JP4862624B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle including a fastening element between a motor and a drive wheel.

The technique of patent document 1 is disclosed as a hybrid vehicle. This publication includes an engine clutch that connects and disconnects the engine and the motor, and an output clutch that connects and disconnects the motor and the drive wheel. When the engine is started, the output clutch is slip-controlled and the engine clutch is engaged to start the engine. It is possible.
JP 2000-255285 A

However, with the technique described in Patent Document 1, there are concerns about the problems listed below.
(Problem 1) When the engagement speed of the engine clutch is slow, the engine clutch stays in the low-speed resonance band of the engine, and sound vibration such as floor vibration becomes a problem.

  (Problem 2) On the other hand, when the engagement speed of the engine clutch is fast, the engine inertia is large, and therefore a load more than expected is applied to the motor generator MG. As a result, even if the motor generator MG is controlled in rotational speed, the motor rotational speed is reduced, the output clutch cannot be slip controlled, and sufficient torque is not output to the output shaft, resulting in a driving force shock. There is a fear.

  (Problem 3) If the engine clutch engagement force is weak, the engine clutch may not be completely engaged if the engine torque after the engine complete explosion exceeds the engagement capacity of the engine clutch.

  (Problem 4) If the state where the engagement force of the engine clutch is weak continues, there is a concern that the state where the rotational speed difference between the engine and the motor generator is large may continue, and there is a concern that durability may be deteriorated due to heat generation.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a hybrid vehicle control device capable of avoiding a decrease in the number of revolutions of a motor generator while quickly passing through a low-rotation resonance band when the engine is started. And

In order to achieve the above object, according to the present invention, an engine, a motor generator connected to drive wheels, a first fastening element interposed between the engine and the motor generator, and the engine within a target time. The engine speed is set to the target start time by the difference between the torque capacity required to increase the startable speed and the reached motor generator speed converted from the vehicle speed after the target time and the engine startable speed. A holding fastening capacity setting means for setting a holding fastening capacity based on a torque capacity required to be raised inward, and the holding fastening of the first fastening element at a predetermined gradient when starting the engine. And fastening capacity holding means for raising and holding the capacity.

  Therefore, in the vehicle control apparatus of the present invention, it is possible to quickly pass through the low-rotation resonance band, and after the engine is started, the first fastening element can be completely fastened even when the vehicle is accelerating. can do.

  Hereinafter, the best mode for realizing a control device for a hybrid vehicle of the present invention will be described based on an embodiment shown in the drawings.

  First, the drive system configuration of the hybrid vehicle will be described. FIG. 1 is an overall system diagram showing a hybrid vehicle driven by rear wheels of the first embodiment. As shown in FIG. 1, the drive system of the hybrid vehicle in the first embodiment includes an engine E, a flywheel FW, a first clutch CL1, a motor generator MG, a second clutch CL2, an automatic transmission AT, It has a propeller shaft PS, a differential DF, a left drive shaft DSL, a right drive shaft DSR, a left rear wheel RL (drive wheel), and a right rear wheel RR (drive wheel). Note that FL is the left front wheel and FR is the right front wheel.

  The engine E is a gasoline engine or a diesel engine, and the valve opening degree of the throttle valve and the like are controlled based on a control command from an engine controller 1 described later. The engine output shaft is provided with a flywheel FW.

  The first clutch CL1 is a clutch interposed between the engine E and the motor generator MG, and the control created by the first clutch hydraulic unit 6 based on a control command from the first clutch controller 5 described later. The hydraulic pressure controls the fastening and opening including slip fastening and slip opening.

  The motor generator MG is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and the three-phase AC generated by the inverter 3 is generated based on a control command from a motor controller 2 described later. It is controlled by applying. The motor generator MG can operate as an electric motor that is driven to rotate by receiving power supplied from the battery 4 (hereinafter, this state is referred to as “power running”), or when the rotor is rotated by an external force. Can function as a generator that generates electromotive force at both ends of the stator coil to charge the battery 4 (hereinafter, this operation state is referred to as “regeneration”). The rotor of the motor generator MG is connected to the input shaft of the automatic transmission AT via a damper (not shown).

  The second clutch CL2 is a clutch interposed between the motor generator MG and the left and right rear wheels RL and RR, and is generated by the second clutch hydraulic unit 8 based on a control command from the AT controller 7 described later. The tightening / release including slip fastening and slip opening is controlled by the control hydraulic pressure.

  The automatic transmission AT is a transmission that automatically switches the stepped gear ratio such as 5 forward speeds, 1 reverse speed, etc. according to the vehicle speed, accelerator opening, etc., and the second clutch CL2 is newly added as a dedicated clutch However, some frictional engagement elements are used among a plurality of frictional engagement elements that are engaged at each gear stage of the automatic transmission AT. Details will be described later.

  The output shaft of the automatic transmission AT is connected to the left and right rear wheels RL and RR via a propeller shaft PS, a differential DF, a left drive shaft DSL, and a right drive shaft DSR. The first clutch CL1 and the second clutch CL2 are, for example, wet multi-plate clutches that can continuously control the oil flow rate and hydraulic pressure with a proportional solenoid.

  This hybrid drive system has three travel modes according to the engaged / released state of the first clutch CL1. The first travel mode is an electric vehicle travel mode (hereinafter, abbreviated as “EV travel mode”) as a motor use travel mode in which the first clutch CL1 is disengaged and travels using only the power of the motor generator MG as a power source. It is. The second travel mode is an engine use travel mode (hereinafter abbreviated as “HEV travel mode”) in which the first clutch CL1 is engaged and the engine E is included in the power source.

  The third travel mode is an engine-use slip travel mode (hereinafter referred to as “WSC (Wet Start Clutch) travel mode) in which the first clutch CL1 is engaged and the second clutch CL2 is slip-controlled and the engine E is included in the power source. For short). This mode achieves creep running especially when the battery SOC is low or the engine water temperature is low. Furthermore, in this mode, the driving force can be output while starting the engine when starting from the engine stopped state.

  The “HEV travel mode” has three travel modes of “engine travel mode”, “motor assist travel mode”, and “travel power generation mode”.

  In the “engine running mode”, the drive wheels are moved using only the engine E as a power source. In the “motor assist travel mode”, the drive wheels are moved by using the engine E and the motor generator MG as power sources. The “running power generation mode” causes the motor generator MG to function as a generator at the same time as the drive wheels RR and RL are moved using the engine E as a power source.

  During constant speed operation or acceleration operation, motor generator MG is operated as a generator using the power of engine E. Further, during deceleration operation, braking energy is regenerated and electric power is generated by the motor generator MG and used for charging the battery 4.

  Further, as a further mode, there is a power generation mode in which the motor generator MG is operated as a generator using the power of the engine E when the vehicle is stopped.

  Next, the control system of the hybrid vehicle will be described. As shown in FIG. 1, the hybrid vehicle control system according to the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a first clutch controller 5, and a first clutch hydraulic unit 6. The AT controller 7, the second clutch hydraulic unit 8, the brake controller 9, and the integrated controller 10 are configured. The engine controller 1, the motor controller 2, the first clutch controller 5, the AT controller 7, the brake controller 9, and the integrated controller 10 are connected via a CAN communication line 11 that can exchange information with each other. ing.

  The engine controller 1 inputs the engine water temperature from the engine water temperature sensor 1 a and the engine speed information from the engine speed sensor 12, and according to the target engine torque command from the integrated controller 10, the engine operating point (Ne, Te For example, to a throttle valve actuator (not shown). In the engine controller 1, an engine torque estimation unit 1b that estimates the engine torque Teng based on the fuel injection amount of the engine E, the throttle opening, and the like is provided. Information on the engine speed Ne and the estimated engine torque Teng is supplied to the integrated controller 10 via the CAN communication line 11.

  The motor controller 2 inputs information from the resolver 13 that detects the rotor rotation position of the motor generator MG, and the motor operating point (Nm, Tm) of the motor generator MG in accordance with a target motor generator torque command or the like from the integrated controller 10. Is output to the inverter 3. The motor controller 2 monitors the battery SOC indicating the state of charge of the battery 4. The battery SOC information is used for control information of the motor generator MG and is supplied to the integrated controller 10 via the CAN communication line 11. To do.

  Further, a motor generator torque estimation unit 2b that estimates the motor generator torque Tmg based on the value of the current flowing through the motor generator MG (the driving torque and the regenerative torque are distinguished based on whether the current value is positive or negative) is provided. Information on the estimated motor generator torque Tmg is supplied to the integrated controller 10 via the CAN communication line 11.

  The first clutch controller 5 inputs sensor information from the first clutch hydraulic pressure sensor 14 and the first clutch stroke sensor 15, and according to the first clutch control command from the integrated controller 10, the first clutch CL1 is engaged / released. A command to control is output to the first clutch hydraulic unit 6. Information on the first clutch stroke C1S is supplied to the integrated controller 10 via the CAN communication line 11.

  The AT controller 7 inputs sensor information from the accelerator opening sensor 16, the vehicle speed sensor 17, and the second clutch hydraulic pressure sensor 18, and engages / disengages the second clutch CL2 in response to the second clutch control command from the integrated controller 10. A command for controlling opening is output to the second clutch hydraulic unit 8 in the AT hydraulic control valve. Information on the accelerator pedal opening APO and the vehicle speed VSP is supplied to the integrated controller 10 via the CAN communication line 11.

  The brake controller 9 inputs sensor information from a wheel speed sensor 19 and a brake stroke sensor 20 that detect the wheel speeds of the four wheels. For example, when the brake is depressed, braking is performed with respect to the required braking force obtained from the brake stroke BS. When the braking force is insufficient, the regenerative cooperative brake control is performed based on the regenerative cooperative control command from the integrated controller 10 so that the shortage is supplemented by the mechanical braking force (hydraulic braking force or motor braking force).

  The integrated controller 10 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The integrated controller 10 detects the motor rotational speed Nm, and the second clutch output rotational speed N2out. A second clutch output speed sensor 22 that detects the second clutch torque TCL2, a second clutch torque sensor 23 that detects the second clutch torque TCL2, a brake hydraulic pressure sensor 24, a temperature sensor 10a that detects the temperature of the first clutch CL1, Information from the temperature sensor 10b that detects the temperature of the two-clutch CL2 and information obtained through the CAN communication line 11 are input.

  The integrated controller 10 also controls the operation of the engine E according to the control command to the engine controller 1, the operation control of the motor generator MG based on the control command to the motor controller 2, and the first control command to the first clutch controller 5. Engagement / release control of the clutch CL1 and engagement / release control of the second clutch CL2 by a control command to the AT controller 7 are performed.

  Below, the control calculated by the integrated controller 10 of Example 1 is demonstrated using the block diagram shown in FIG. For example, this calculation is performed by the integrated controller 10 every control cycle of 10 msec. The integrated controller 10 includes a target driving force calculation unit 100, a mode selection unit 200, a target charge / discharge calculation unit 300, an operating point command unit 400, and a shift control unit 500.

  The target driving force calculation unit 100 calculates a target driving force tFoO from the accelerator pedal opening APO and the vehicle speed VSP using the target driving force map shown in FIG.

  The mode selection unit 200 calculates a target mode from the accelerator pedal opening APO and the vehicle speed VSP using the EV-HEV selection map shown in FIG. However, if the battery SOC is equal to or less than the predetermined value, the “HEV travel mode” is forcibly set as the target mode. In the EV-HEV selection map, the WSC mode is set in order to output a large driving force when the accelerator pedal opening APO is large in the low vehicle speed range. The HEV → WSC switching line or EV → WSC switching line is set in a region lower than the vehicle speed VSP1 at which the rotational speed is smaller than the idle rotational speed of the engine E when the automatic transmission AT is in the first gear. A hatched area in FIG. 4 is an area where the HEV traveling mode is switched to the WSC traveling mode, and a shaded area in FIG. 4 is an area where the WSC traveling mode is switched to the EV traveling mode.

  The target charge / discharge calculation unit 300 calculates the target charge / discharge power tP from the battery SOC using the target charge / discharge amount map shown in FIG.

  The operating point command unit 400 uses the accelerator pedal opening APO, the target driving force tFoO, the target mode, the vehicle speed VSP, and the target charging / discharging power tP as a target for reaching the operating point, as a transient target engine torque. And target motor generator torque, target second clutch engagement torque, target automatic shift shift, and first clutch solenoid current command. The operating point command unit 400 is provided with an unillustrated engine start control unit that starts the engine E when the EV travel mode is changed to the HEV travel mode.

  The shift control unit 500 drives and controls the solenoid valve in the automatic transmission AT so as to achieve each clutch engagement torque and the target shift stage according to a preset shift schedule. In this shift schedule, a target gear stage is set in advance based on the vehicle speed VSP and the accelerator pedal opening APO, and an upshift line, a downshift line, and the like are set.

  Further, in the operating point command unit 400, a target engagement torque calculation unit 401 that calculates a target engagement torque based on the target driving force tFoO, and an engagement that controls the engagement torque of the second clutch CL2 to be the target engagement torque. A torque control unit 402 and a motor rotation speed control unit 403 that controls the rotation speed of the motor generator MG so that the rotation speed on the motor generator MG side is higher than the rotation speed on the drive wheel side of the second clutch CL2. Yes.

  Further, the motor torque control unit 404 that controls the motor generator torque Tmg based on the target driving force tFoO, and the engagement torque of the second clutch CL2 based on the estimated motor generator torque Tmg, engine torque Teng, and motor generator rotational speed Nmg. And a switching unit 406 for switching between control by the motor rotation speed control unit 403 and control by the motor torque control unit 404 based on the second clutch engagement torque estimated as the target engagement torque. ing.

(Reason for motor speed control and motor torque control)
Here, the reason for switching between the motor rotation speed control unit 403 and the motor torque control unit 404 will be described.

(Necessity 1): [Necessity to perform slip control of second clutch CL2]
When traveling at a certain vehicle speed, it is most efficient to fully engage the second clutch CL2, control the torque of the motor generator MG and the engine E, and control the torque of the drive wheels.

  On the other hand, when the vehicle starts, the motor generator rotational speed gradually increases from the state where the drive wheels are stopped. At this time, if the engine E is stopped and the first clutch CL1 is released, it is possible to start only by the driving force of the motor generator MG with the second clutch CL2 fully engaged.

  However, when the vehicle starts as described above, the motor generator MG becomes less efficient because it outputs extremely low rotation and high torque, which is not preferable. In addition, when the engine E start request is made and torque is required for engine cranking, the upper limit of the motor generator torque Tmg needs to be allowed to some extent, and when starting as described above There are times when sufficient starting performance cannot be ensured. Further, when the engine E is being driven, it is necessary to ensure the idling speed of the engine E, and if the second clutch CL2 is completely engaged, there is a possibility of causing an engine stall.

  Furthermore, when starting with only the motor generator MG, a greater driving force may be required during the start and an engine start request may be made. In order to meet this request, the first clutch CL1 is engaged and the engine clutch is engaged. Ranking will be executed. At this time, a large load is suddenly applied to the motor generator MG, and the motor generator rotational speed may be reduced at a stretch, which may cause fluctuations in driving wheel speed and driving torque.

  Therefore, at the time of start, the second clutch CL2 controls the fastening torque so as to achieve the target driving force, and maintains the slip state (slip control). At this time, the motor generator MG can cope with various start scenes by independently controlling control such as engine start while achieving the target driving force.

(Necessity 2): [Necessity to execute motor speed control during slip control]
As described above, when the torque of the motor generator MG is controlled during the slip control of the second clutch CL2, the engine generator MG achieves at least the target driving force, and if an engine start request is further made, It is necessary to drive by adding the torque required for ranking. The torque required for engine cranking and the torque transmitted to the engine via the first clutch CL1 are determined by the state of the engine, such as the engine water temperature, and the speed of the required engine start. Since the torque varies greatly depending on the fastening torque, it is necessary to add a torque that can reliably crank the engine to the motor generator torque when an engine start request is made.

  When the actual torque required for engine cranking is small, the load acting on motor generator MG becomes very small, and the rotational speed of motor generator MG increases at a stretch. At this time, since the second clutch CL2 only outputs a torque corresponding to the engagement torque to the drive wheels, the rotational speed of the drive wheels does not change suddenly. Therefore, the slip amount in the second clutch CL2 becomes excessive. This leads to a deterioration in durability of the second clutch CL2, which is not preferable.

  Therefore, when the second clutch CL2 is slip-controlled, motor rotation speed control is performed to control the rotation speed of the motor generator MG to maintain a predetermined rotation speed slightly higher than the rotation speed of the drive wheels. did. In order for motor generator MG to maintain a slightly higher rotational speed, a torque larger than the engagement torque of second clutch CL2 is required. Therefore, if the rotational speed control is performed, motor generator torque Tmg is inevitably higher than target driving force tFoO. Should be set higher.

  In addition, since a target rotational speed is set for motor generator MG, even if a large torque is generated in motor generator MG as a torque for achieving this target rotational speed, this target rotational speed will be greatly exceeded. There is no.

  Thereby, motor generator MG does not rotate excessively, and a decrease in durability of second clutch CL2 can be suppressed.

(Necessity 3): [Necessity of torque control after complete fastening]
Next, when a predetermined condition is satisfied, it is desirable to completely engage the second clutch CL2 from the viewpoint of durability of the second clutch CL2. However, if the second clutch CL2 is completely engaged while the motor generator MG is under motor speed control, there are the following problems.

  In general, the vehicle controls the torque of the drive wheels based on the driver's intention, that is, the accelerator pedal opening. In other words, the driver does not control the vehicle speed with the accelerator pedal, but controls the torque. When the motor generator MG is controlled at the rotational speed as described above with the second clutch CL2 fully engaged, torque corresponding to the deviation from the target rotational speed is output, and torque that does not match the driver's intention is generated. It is given to the driving wheel and gives a sense of incongruity.

  Also, from the viewpoint of durability, it is difficult to slip the second clutch CL2 steadily. After the start control processing and the like are completed, the second clutch CL2 is completely engaged, and the engine E and the motor generator MG It is desirable to switch to torque control.

  In the first embodiment, therefore, the slip control is shifted to the complete fastening when the predetermined condition is satisfied due to the necessity 1 and 2, and the motor rotation speed control is switched to the motor torque control according to the necessity 3. is there.

  Next, the engine start control process according to the first embodiment will be described. FIG. 6 is a flowchart showing the engagement control process of the second clutch CL2 at the time of engine start.

  In step S1, it is determined whether there is an engine start request. When this condition is satisfied, the process proceeds to step S2, and otherwise, the present control flow ends.

  In step S2, the target engagement torque of the second clutch CL2 is calculated based on the target driving force tFoO, and the engagement torque control is executed so that the engagement torque of the second clutch CL2 becomes the target engagement torque. Here, the actual engagement torque TCl2 estimated in step S4 described later is used for detection of the actual engagement torque when executing the engagement torque control.

  The reason for executing the engagement torque control of the second clutch CL2 at the time of starting is that, as explained in the necessity 1, if the engagement torque of the second clutch CL2 is controlled, the input side (engine E or motor generator MG) This is because no torque higher than the engagement torque of the second clutch CL2 is output to the drive wheel side, and a stable running state can be achieved no matter how the torque of the motor fluctuates.

  In step S3, motor rotation speed control is executed so that the rotation speed on the motor generator MG side is higher than the rotation speed on the drive wheel side of the second clutch CL2. The reason for executing the motor rotation speed control is as described in the necessity 2 above. Here, the motor rotation speed control refers to a value obtained by reading the rotation speed on the driving wheel side of the second clutch CL2 and adding a predetermined slip amount γ to the rotation speed on the driving wheel side on the motor generator side of the second clutch CL2. Set as target speed Nm *. Then, a target motor generator rotational speed is set in consideration of a predetermined gear ratio so that the target rotational speed Nm * can be achieved, and the motor generator MG is controlled so as to maintain this rotational speed. Therefore, as a command value to motor generator MG, a command value based on a deviation between target rotation speed Nm * and actual rotation speed Nm is output.

  At this time, how much torque is generated in motor generator MG is not a final control target. Therefore, the motor generator torque estimation unit 2b provided in the motor controller 2 estimates the motor generator torque based on the current value flowing through the motor generator MG, and transmits the estimated motor generator torque Tmg to the integrated controller 10.

  In this way, by using the motor generator MG as the rotational speed control and the second clutch CL2 as the engagement torque control, it is possible to ensure that the value corresponding to the engagement torque of the second clutch CL2 is reliably output to the drive wheels. This is because the motor generator MG needs to maintain its own rotational speed that is higher by a predetermined rotational speed γ than the rotational speed on the drive wheel side of the second clutch CL2, and the torque for maintaining this rotational speed is the second clutch. This is because it cannot be achieved unless it is higher than the fastening torque.

  In step S4, the actual engagement torque TCL2 of the second clutch CL2 is estimated. In this estimation, the engaged state of the first clutch CL1 is detected, and an estimation corresponding to each when the clutch is in the released state, in the engaged state, and during slip control is performed.

  The engagement state of the first clutch CL1 is determined based on other control logic. When the engine needs to be started (request for transition to the HEV travel mode), the slip control is performed and the engine E is started. When torque is output in this state (HEV traveling mode), the engaged state is established, and when the driving force of the engine E is not required (EV traveling mode), the activated state is established.

  In step S5, it is determined whether or not the estimated engagement torque TCL2 of the second clutch CL2 is within a predetermined range in consideration of the error a with respect to the target driving force tFoO. If it is within the predetermined range, the process proceeds to step S6. In other cases, Steps S2 to S9 are repeated until the second clutch engagement torque TCL2 falls within a predetermined range.

  In step S6, control is performed so that the predetermined slip amount becomes zero from the control for securing the predetermined slip amount γ as the motor rotation speed control. That is, motor generator MG outputs a higher torque to ensure a predetermined slip amount γ, and naturally the rotational speed is higher than the rotational speed transmitted to the drive wheel side. If the second clutch CL2 is completely engaged in this state, the inertia torque on the input side of the second clutch CL2 is output to the drive wheel side, resulting in fluctuations in output torque, which may cause the driver to feel uncomfortable. is there.

  Further, if the engagement torque TCL2 of the second clutch CL2 is simply increased while the motor rotation speed control is being performed, the motor generator MG outputs a large drive torque to ensure the slip amount γ.

  Therefore, the slip amount ΔN2 of the second clutch CL2 is gradually decreased by controlling the motor rotation speed control so that the slip amount ΔN2 becomes zero and gradually decreasing the torque of the motor generator.

  In step S7, it is determined whether or not the slip amount ΔN2 of the second clutch CL2 is less than a predetermined value β that represents an allowable range in which torque fluctuation when fully engaged is considered to be small. If it is less than the predetermined value β, the process proceeds to step S8. In other cases, the process returns to step S6 to control the slip amount ΔN2 to be small.

  In step S8, the motor speed control is switched to the motor torque control, and in step S9, the second clutch CL2 is completely engaged.

  Next, the operation based on the control process will be described. In describing the operation of the first embodiment, a comparative example will be used to clarify the features. FIG. 7 is a time chart when the engagement control of the second clutch CL2 in the comparative example is performed.

  For the sake of explanation, the notation on the time chart is defined as follows. The input torque is the input side of the second clutch CL2, and is a value that takes into account the engine torque Teng, the motor generator torque Tmg, and the engaged state of the first clutch CL1. The clutch torque is an engagement torque of the second clutch CL2. The slip rotation speed is the slip amount of the second clutch CL2. The output torque is torque transmitted to the drive wheels. The comparative example represents a case where the engagement torque of the second clutch CL2 is controlled while the input torque is constant.

  As shown in FIG. 7, the input torque is constant, and the second clutch CL2 generates a predetermined slip amount by the slip control. Note that the input side of the second clutch CL2 rotates at a higher speed than the output side. At this time, when the second clutch CL2 is completely engaged from the slip control, since the input torque is controlled to be constant, the engagement torque of the second clutch CL2 is increased to suppress the input side rotational speed of the second clutch CL2. (See (i) in FIG. 7).

  At this time, the load on the input side increases and the rotational speed starts to decrease, but the input torque itself is not changed by the constant input torque control. At this time, the inertia torque on the input side is output to the output side due to the change in the rotational speed on the input side, and the output torque varies. As a result, the driver may feel uncomfortable.

  FIG. 8 is a time chart when the engagement control of the second clutch CL2 in the first embodiment is performed. In the description of the action based on the comparison with the comparative example, the solid line in FIG. 8 represents the action of the first embodiment.

  As shown in FIG. 8, the input torque is shown to be constant, but this torque is merely the torque required to secure the slip amount of the second clutch CL2, and in particular, the input torque constant control. Is not performed (see (ii) in FIG. 8).

  In this state, when the estimated engagement torque TCL2 of the second clutch CL2 falls within a predetermined range in consideration of the error a with respect to the target driving force tFoO, the motor rotation speed control is executed so that the slip amount becomes zero ( (See (iii) in FIG. 8). At this time, an inertia torque is output when the slip amount becomes zero. Therefore, the inertia torque is absorbed by reducing the input torque, and the fluctuation of the output torque is suppressed.

  When the slip amount becomes substantially zero, the motor speed control is switched to the motor torque control, and the second clutch CL2 is completely engaged. Therefore, since the motor torque control is executed in a state where the second clutch CL2 is completely engaged, a value corresponding to the target driving force is output as the output torque. As described above, in the configuration according to the first embodiment, the second clutch CL2 can be completely engaged without causing fluctuation in the output torque.

  Next, the engagement control process of the first clutch CL1 will be described. As described above, when the engine of the first embodiment is started, the second clutch CL2 is slipped to generate the engagement torque TCL2 corresponding to the required driving force, and the first clutch CL1 is engaged while controlling the rotational speed of the motor generator MG. To start engine E. At this time, there are concerns about the problems listed below.

  (Problem 1) If the engaging speed of the first clutch CL1 is slow, that is, if the inclination of the increasing speed of the engaging capacity of the first clutch CL1 is gentle, the engine E will stay in the low rotation resonance band, floor vibration, etc. The sound vibration is a problem. Here, it was found that the low-rotation resonance band that resonates mainly is a region where the engine speed is 300 to 400 rpm.

  (Problem 2) On the other hand, if the engagement speed of the first clutch CL1 is fast, that is, if the inclination of the increase speed of the engagement capacity of the first clutch CL1 is steep or stepwise, the engine inertia is large and the motor generator MG exceeds the expected value. The load of acts. As a result, even if the motor generator MG is controlled in rotational speed, the motor rotational speed is reduced, the slip amount γ of the second clutch CL2 cannot be secured, and sufficient torque is not output to the output shaft. There is a risk of power loss.

  (Problem 3) If the engagement force of the first clutch CL1 is weak, that is, if the engagement capacity of the first clutch CL1 is small, the engine torque after the complete explosion of the engine exceeds the engagement capacity of the first clutch CL1, the first clutch CL1 May not be able to complete fastening.

  (Problem 4) If the weak state of the first clutch CL is continued, there is a possibility that the state where the engine E and the motor generator MG have a large rotational speed difference may continue, and the durability of the first clutch CL1 due to heat generation or the like may continue. There is concern about deterioration. As a scene where the rotational speed difference is particularly large, a case where a downshift is performed in the automatic transmission AT during engine startup and the motor generator rotational speed Nmg increases can be considered.

  Therefore, in the first embodiment, when the engagement capacity of the first clutch CL1 is increased, the first clutch engagement torque TCL1h capable of avoiding a decrease in the rotation speed of the motor generator MG while quickly passing through the low rotation resonance band is calculated. The fastening capacity according to the fastening torque TCL1h is quickly increased to a fastening capacity, and then temporarily held at the fastening torque TCL1h.

  In addition, when the engagement capacity of the first clutch CL1 is quickly increased, this increase gradient is corrected as appropriate, and all of the above-mentioned problems are solved, and the control state of the rotational speed control in the motor generator MG is also considered and stable. It is possible to output the generated driving force.

  Hereinafter, specific processing for realizing the above concept will be described with reference to the flowchart of FIG. FIG. 9 is a flowchart showing a first clutch engagement capacity control process when the engine is started.

  In step S10, it is determined whether or not there is an engine start request. If there is an engine start request, the process proceeds to step S11. Otherwise, this control flow is terminated.

  In step S11, a precharge process is executed. Here, the precharge process is a process for closing a gap between the clutch plate and the piston. Since the fastening capacity is generated from the time when the gap disappears, it is preliminarily padded. The first clutch CL1 of the first embodiment employs a dry-type constant engagement clutch. When the first clutch CL1 is completely released, the hydraulic pressure is supplied, and when the first clutch CL1 is fully engaged, the hydraulic pressure is not supplied. Therefore, in the precharge process, the hydraulic pressure is temporarily set to the non-supplied state, the backlash is reduced, the hydraulic pressure is supplied again, and the stand-by is set in a state where the engagement capacity can be generated immediately.

  In step S12, the engagement capacity of the first clutch CL1 is raised with a gradient α (initial value). The gradient α is the maximum response gradient of the first clutch CL1, and is set so as to quickly reach a holding engagement capacity TCL1h described later. Basically, if the gradient α is given, it is possible to secure the holding fastening capacity TCL1h that quickly leaves the low-rotation resonance band. The holding fastening capacity TCl1h will be described later.

  In step S13, it is determined whether the P range, N range or the target driving force tFo0 is less than a predetermined value tFo1 indicating that the target driving force tFo0 is very small. If any of the conditions is satisfied, the process proceeds to step S15. Proceed to S14. For example, since the driving force is not output to the output shaft in the P range and N range, for example, even if the rotational speed of the motor generator MG is pulled when the engagement capacity of the first clutch CL1 is excessive, It is sufficient to pass through the low-rotation resonance band quickly without giving the person a sense of incongruity. On the other hand, when the target driving force tFo0 is large, the output shaft is affected by pulling in the rotational speed of the motor generator MG described above. In this case, the process proceeds to step S14.

  In step S14, gradient correction processing is executed. In this gradient correction process, the initial value α is appropriately corrected in accordance with the engine start state, and the influence on the output shaft is reliably eliminated. Details will be described later.

  In step S15, it is determined whether or not the engagement capacity of the first clutch CL1 has reached the holding engagement capacity TCL1h. If it has reached, the process proceeds to step S16, and otherwise, steps S13 and S14 are repeated.

  Here, holding engagement capacity TCl1h is an engagement capacity corresponding to the torque required to raise engine E from a stopped state to a rotation speed synchronized with the rotation speed of motor generator MG within the target start time. Specifically, the capacity required to increase the engine E from the stopped state to the startable rotation speed, and the rotation speed change when the rotation speed of the motor generator MG changes within the target start time due to the acceleration of the vehicle. It is a value set based on the capacity required for this.

  The torque capacity required to raise the engine E to the startable rotational speed is a value determined by the inertia, the friction, the target start time, and the startable rotational speed of the engine E.

  Further, the capacity required to increase the rotational speed of motor generator MG when the rotational speed of motor generator MG changes within the target start time by the acceleration of the vehicle is a torque capacity calculated by the following logical configuration. First, it is estimated how much the vehicle accelerates within the target start time. For this estimation, it is sufficient to estimate the vehicle speed reached from the target driving force tFto0, the running resistance, and the inertia of the vehicle. Next, this estimated vehicle speed is read as a motor generator rotation speed calculated by taking into account the gear ratio of the automatic transmission AT and the final gear ratio such as a differential. Then, the reached motor generator rotational speed at which the motor generator rotational speed reaches within the target start time is calculated, and the deviation between the engine startable rotational speed and the reached motor generator rotational speed is calculated. Then, a torque capable of increasing the deviation within the target start time is calculated in consideration of engine inertia and friction. This torque becomes a capacity necessary for increasing the amount of change of the rotational speed when the rotational speed of the motor generator MG changes within the target start time by the acceleration of the vehicle.

  That is, when starting the engine, it is necessary to quickly pass through the low-rotation resonance band, and it is desired to quickly complete the first clutch CL1 immediately after the engine is completely exploded. At this time, if a deviation remains between the rotation speed of motor generator MG and the engine rotation speed after the engine is completely exploded, it takes time to reduce the deviation, which is not preferable. Further, if the fastening is completed with the deviation remaining, a drawing shock or the like is generated, which is not preferable.

  Therefore, the holding fastening capacity TCl1h is set in advance so that the rotational speed deviation between the engine speed and the motor generator speed becomes small within the engine start time. As a result, the low rotation resonance band can be quickly passed, and the first clutch CL1 can be completely fastened immediately after the engine is started.

  In step S17, it is determined whether or not the slip amount ΔN1 of the first clutch CL1 has become less than the predetermined value a1, or whether the engine speed Ne has become greater than the predetermined value b1, and when any of the conditions is satisfied, step S18 is satisfied. Continue to hold the fastening capacity otherwise.

  In step S18, a complete fastening process is executed. Here, the complete fastening process is to quickly increase from the holding fastening capacity TCL1h to the fastening capacity that can be completely fastened. The fully engaged fastening capacity is a value larger than the fastening capacity at which the slip amount ΔN1 of the first clutch CL1 does not increase even if the engine E completes explosion and starts to rotate independently.

  Next, the gradient correction process in step S14 will be described. FIG. 10 is a flowchart illustrating the MG type gradient correction process according to the first embodiment.

  In step S101, it is determined whether or not the absolute value of the deviation between the target rotational speed Nm * of the motor generator MG and the actual rotational speed Nm is larger than the threshold value. If larger, the process proceeds to step S103. Since the control is possible, the process proceeds to step S102, and the current gradient α of the first clutch CL1 is maintained.

  In step S103, it is determined whether or not the actual rotational speed Nm of the motor generator MG is larger than the target rotational speed Nm *. If so, it is because the motor generator MG is controlled to overshoot in the rotational speed control of the motor generator MG. The process proceeds to step S104. On the other hand, when the actual rotational speed Nm is equal to or less than the target rotational speed Nm *, this is a case where sufficient torque is not secured in the rotational speed control of the motor generator MG, and thus the process proceeds to step S105.

  In step S104, the gradient α of the engagement capacity of the first clutch CL1 is corrected more rapidly. When the increase gradient of the engagement capacity of the first clutch CL1 becomes steep, the load acting on the motor generator MG increases and acts in the direction of lowering the rotation speed of the motor generator MG. It is possible to stabilize the taste control.

  In step S105, the gradient α of the engagement capacity of the first clutch CL1 is corrected more gently. When the increasing gradient of the engagement capacity of the first clutch CL1 becomes gentle, the load acting on the motor generator MG decreases and acts in the direction of increasing the rotation speed of the motor generator MG. Sexual deterioration can be prevented.

  Next, the operation based on the flowchart will be described. FIG. 11 is a time chart showing the engagement capacity control of the first clutch CL1 when an engine start request is made during traveling with a very small target driving force tFto0.

  When an engine start request is made at time t1, precharge processing is executed. This precharge process is managed by a timer or the like, and it is determined that the precharge process is completed after a predetermined time has elapsed.

  At time t2, the engagement capacity of the first clutch CL1 is increased by the gradient α. At this time, the fastening capacity is maintained after rising to TCL1h. As a result, the engine speed Ne passes through the low-speed resonance band quickly.

  At time t3, when the engine speed increases and the slip amount ΔN1 of the first clutch CL1 is less than the predetermined value a1 or the engine speed Ne is larger than the predetermined speed b1 representing the complete explosion determination, the engagement capacity holding is finished. The process proceeds to a complete fastening process. At time t4, the complete fastening process ends and the engine start is completed.

  FIG. 12 is a time chart showing the engagement capacity control of the first clutch CL1 when an engine start request is made during traveling with a large target driving force tFto0.

  From time t1 to time t2 is the same as the time chart shown in FIG.

  When the actual rotational speed Nm of the motor generator MG falls below the target rotational speed Nm * at time t3, the gradient α is corrected so as to be gentle. Then, the load acting on motor generator MG is reduced and acts in the direction of increasing the rotational speed of motor generator MG, so that it is possible to prevent the follow-up performance from being deteriorated in the rotational speed control of motor generator MG.

  When the engagement capacity of the first clutch CL1 reaches TCL1h at time t4, it is held. As a result, the engine speed Ne passes through the low-speed resonance band quickly.

  At time t5, when the engine speed increases and the slip amount ΔN1 of the first clutch CL1 is less than the predetermined value a1 or the engine speed Ne is greater than the predetermined speed b1 representing the complete explosion determination, the engagement capacity holding is terminated. The process proceeds to a complete fastening process. At time t6, the complete fastening process is completed and the engine start is completed.

  As described above, in the configuration of the first embodiment, the following effects can be obtained.

  (1) When setting the holding fastening capacity TCl1h according to the torque required to pull up the engine E to the rotational speed synchronized with the rotational speed of the motor generator MG within the target start time, The engagement capacity of the clutch CL1 is raised to a holding engagement capacity TCl1h with a predetermined gradient and held. Specifically, as the holding fastening capacity TCl1h, the capacity required to raise the engine E to the startable speed, and the speed change when the speed of the motor generator MG changes within the target start time due to acceleration of the vehicle The holding fastening capacity TCl1h was set based on the capacity required to raise it by the minute.

  As a result, the low-rotation resonance band can be quickly passed, and even when the vehicle is accelerating, the first clutch CL1 can be fully engaged quickly after the engine is started.

  (2) The predetermined gradient α is the maximum response gradient of the first fastening element. Therefore, the low rotation resonance band can be passed quickly, and the time required for engine start can be shortened.

  (3) The holding is continued until the slip amount ΔN1 of the first clutch CL1 is equal to or less than the predetermined value a1 or the engine speed Ne is equal to or higher than the startable speed b1. Therefore, the first clutch CL1 can be completely engaged after the engine rotation speed and the motor generator rotation speed are synchronized, and the clutch engagement shock can be suppressed. Further, since the complete engagement transition can be performed with the clutch slip amount being small, heat generation and durability deterioration can be suppressed.

  (4) When the holding of the engagement capacity of the first clutch CL1 is finished, the first clutch CL1 is raised to the complete engagement capacity with the maximum response gradient of the first clutch CL1. Therefore, the engine start can be completed quickly.

  (5) Having the second clutch CL2 interposed between the motor generator MG and the driving wheel, when starting the engine E, the slip control is performed so that the second clutch CL2 has a target driving force engagement capacity. To do. Then, the target rotational speed Nm * obtained by adding the predetermined rotational speed γ to the driving wheel side rotational speed of the second clutch CL1 is set, and the rotational speed is controlled so that the motor generator MG becomes the target rotational speed Nm *. At this time, when the actual rotation speed Nm of the motor generator MG is smaller than the target rotation speed Nm *, a gradient correction process for correcting the predetermined gradient α to be gentle is executed.

  The actual rotational speed Nm is smaller than the target rotational speed Nm * when the motor generator MG does not have sufficient torque in the rotational speed control of the motor generator MG. At this time, by correcting the predetermined gradient α so as to be gentle, the engagement capacity of the first clutch CL1 is prevented from becoming excessive, and the actual rotational speed Nm of the motor generator MG is increased so that it acts. Stable engine start control can be achieved.

  Basically, the predetermined gradient α corresponds to the maximum response speed, but after correcting the predetermined gradient α to be gentle as described above, the actual rotational speed Nm of the motor generator MG becomes the target rotational speed Nm *. The case where it becomes larger than this can be assumed. At this time, by correcting the predetermined gradient α to be steep, the shortage of the engagement capacity of the first clutch CL1 can be solved, and the actual rotational speed Nm of the motor generator MG can be increased.

  In the first embodiment, the gradient correction process is executed according to the deviation between the target rotational speed Nm * of the motor generator MG and the actual rotational speed Nm. This deviation is the same as the slip amount ΔN2 of the second clutch CL2. Is the value of That is, when the rotational speed control of the motor generator MG is assumed, the target rotational speed Nm * of the motor generator MG is a value obtained by adding the predetermined rotational speed γ to the rotational speed on the output side of the second clutch CL2, and the second clutch The slip amount of CL2 is controlled to be γ in the first place. When the slip amount ΔN2 of the second clutch CL2 is smaller than γ is the same as when the actual rotational speed Nm of the motor generator MG is smaller than the target rotational speed Nm *, and when the slip amount ΔN2 is larger than γ, the motor generator This is because the actual rotation speed Nm of MG is the same as when the rotation speed is larger than the target rotation speed Nm *.

  Therefore, the gradient correction process based on the rotation speed of motor generator MG can obtain the same effect as the gradient correction process based on slip amount ΔN2 of second clutch CL2.

  Next, Example 2 will be described. Since the basic configuration is the same as that of the first embodiment, only different points will be described.

  In the first embodiment, in step S14 shown in FIG. 9, as a gradient correction process, as shown in FIG. 10, the relationship between the target rotational speed Nm * of the motor generator MG and the actual rotational speed Nm (or the slip amount of the second clutch CL2). Correction based on ΔN2). In contrast, the second embodiment is different in that the correction is made based on the slip amount ΔN1 of the first clutch CL1.

  FIG. 13 is a flowchart illustrating the gradient correction process according to the second embodiment. It is assumed that when the gradient correction process is executed, the rotational speed control of motor generator MG is accurately performed.

  In step S201, it is determined whether or not the absolute value of the deviation between the target slip amount ΔN1 * of the first clutch CL1 and the actual slip amount ΔN1 is larger than the threshold value. If larger, the process proceeds to step S203. Since it is well controlled, the process proceeds to step S202, and the current gradient α of the first clutch CL1 is maintained.

  The target slip amount ΔN1 * is set so that the slip amount gradually decreases within the target start time so as to avoid a fastening shock or the like, and is set in advance on a map or the like. Therefore, an appropriate target slip amount ΔN1 * is read from the map for each control cycle, and the target value is sequentially updated.

  In step S203, it is determined whether or not the actual slip amount ΔN1 of the first clutch CL1 is smaller than the target slip amount ΔN1 *. If the actual slip amount ΔN1 is smaller, it is larger than the engagement torque assumed by the first clutch CL1, and the motor generator MG Since an excessive load may act, at this time, the process proceeds to step S205. On the other hand, when the actual slip amount ΔN1 is less than or equal to the target slip amount ΔN1 *, the engagement amount is smaller than the engagement torque assumed by the first clutch CL1, and the slip amount is larger. At this time, the process proceeds to step S204.

  In step S204, the gradient α of the engagement capacity of the first clutch CL1 is corrected more rapidly. When the increase gradient of the engagement capacity of the first clutch CL1 becomes steep, the action of increasing the engine speed Ne becomes stronger, and the engagement shock or the like can be avoided by reducing the slip amount ΔN1.

  In step S205, the gradient α of the engagement capacity of the first clutch CL1 is corrected more gently. When the increase gradient of the engagement capacity of the first clutch CL1 becomes gentle, the increase speed of the engine speed Ne decreases, and the engagement shock or the like can be avoided by increasing the slip amount ΔN1.

  Next, the operation based on the flowchart will be described. FIG. 14 is a time chart showing the engagement displacement control of the first clutch CL1 when an engine start request is made during traveling with a large target driving force tFto0.

  When an engine start request is made at time t1, precharge processing is executed. This precharge process is managed by a timer or the like, and it is determined that the precharge process is completed after a predetermined time has elapsed.

  At time t2, the engagement capacity of the first clutch CL1 is increased by the gradient α.

  When the actual slip amount ΔN1 of the first clutch CL1 is lower than the target slip amount ΔN1 * at time t3, the gradient α is corrected so as to be gentle. Then, the torque for raising the engine speed Ne decreases, and the slip amount ΔN1 increases, so that the target slip amount ΔN1 * is approached, and a fastening shock or the like can be suppressed.

  When the engagement capacity of the first clutch CL1 reaches TCL1h at time t4, it is held. As a result, the engine speed Ne passes through the low-speed resonance band quickly.

  At time t5, when the engine speed increases and the slip amount ΔN1 of the first clutch CL1 is less than the predetermined value a1 or the engine speed Ne is greater than the predetermined speed b1 representing the complete explosion determination, the engagement capacity holding is terminated. The process proceeds to a complete fastening process. At time t6, the complete fastening process is completed and the engine start is completed.

  As described above, in the configuration of the second embodiment, the following effects can be obtained in addition to (1) to (4) of the first embodiment.

  (6) Having the second clutch CL2 interposed between the motor generator MG and the driving wheel, when starting the engine E, the slip control is performed so that the second clutch CL2 has the engagement capacity of the target driving force. To do. Then, the target rotational speed Nm * obtained by adding the predetermined rotational speed γ to the driving wheel side rotational speed of the second clutch CL1 is set, and the rotational speed is controlled so that the motor generator MG becomes the target rotational speed Nm *. At this time, when the slip amount ΔN1 of the first clutch CL1 is smaller than the target slip amount ΔN1 *, a gradient correction process for correcting the predetermined gradient α to be gentle is executed.

  When actual slip amount ΔN1 is smaller than target slip amount ΔN1 *, it is larger than the engagement torque assumed by first clutch CL1, and an excessive load may be applied to motor generator MG. At this time, by correcting the engagement capacity gradient α of the first clutch CL1 more gently, the rising speed of the engine speed Ne is reduced, and the slip amount ΔN1 is increased to avoid an engagement shock or the like. Can do.

  On the other hand, when the actual slip amount ΔN1 is equal to or less than the target slip amount ΔN1 *, the slip amount is smaller than the engagement torque assumed by the first clutch CL1. At this time, by correcting the engagement capacity gradient α of the first clutch CL1 more rapidly, the action of increasing the engine speed Ne is strengthened, and by reducing the slip amount ΔN1, an engagement shock or the like can be avoided. Can do.

  Next, Example 3 will be described. In the first and second embodiments, it is assumed that the motor generator MG is switched to the rotational speed control when the engine is started. In contrast, in the third embodiment, it is assumed that the motor generator MG always performs torque control.

  FIG. 15 is a block diagram illustrating a control configuration of the integrated controller 10 according to the third embodiment. When compared with the control configuration shown in FIG. 2, the difference is that an engine start-time motor torque control unit 4031 is provided instead of the motor rotation speed control unit 403 of FIG.

  When an engine start request is made, the engine start-time motor torque control unit 4031 sets a torque obtained by adding a torque required for engine start in addition to a normal target drive force to the engine start target torque Tmg *, Feedback control is performed to achieve this torque.

  FIG. 16 is a flowchart showing the engagement control process of the second clutch CL2 at the time of engine start.

  In step S1, it is determined whether there is an engine start request. When this condition is satisfied, the process proceeds to step S2, and otherwise, the present control flow ends.

  In step S2, the target engagement torque of the second clutch CL2 is calculated based on the target driving force tFoO, and the engagement torque control is executed so that the engagement torque of the second clutch CL2 becomes the target engagement torque. Here, the actual engagement torque TCL2 estimated in step S4 described later is used for detection of the actual engagement torque when executing the engagement torque control.

  The reason for executing the engagement torque control of the second clutch CL2 at the time of starting is that, as explained in the necessity 1, if the engagement torque of the second clutch CL2 is controlled, the input side (engine E or motor generator MG) This is because no torque higher than the engagement torque of the second clutch CL2 is output to the drive wheel side, and a stable running state can be achieved no matter how the torque of the motor fluctuates.

  In step S3 ′, in addition to the driving force for achieving the normal target driving force, the torque obtained by adding the torque necessary for starting the engine is set as the target torque Tmg *, and feedback control is performed to achieve this torque. . Therefore, the command value to motor generator MG is output based on the deviation between target torque Tmg * and actual torque Tmg.

  When the motor generator MG is set to torque control and the second clutch CL2 is set to engagement torque control, torque higher than the target driving force is applied to the motor generator MG, so that the second clutch CL2 is surely applied to the driving wheels. It can be ensured that the value corresponding to the fastening torque is output. At this time, torque fluctuation or the like is not transmitted to the drive wheels because the second clutch CL2 is in the slip state.

  In step S4, the actual engagement torque TCL2 of the second clutch CL2 is estimated. In this estimation, the engaged state of the first clutch CL1 is detected, and an estimation corresponding to each when the clutch is in the released state, in the engaged state, and during slip control is performed.

  The engagement state of the first clutch CL1 is determined based on other control logic. When the engine needs to be started (request for transition to the HEV travel mode), the slip control is performed and the engine E is started. When torque is output in this state (HEV traveling mode), the engaged state is established, and when the driving force of the engine E is not required (EV traveling mode), the activated state is established.

  In step S5, it is determined whether or not the estimated engagement torque TCL2 of the second clutch CL2 is within a predetermined range in consideration of the error a with respect to the target driving force tFoO. If it is within the predetermined range, the process proceeds to step S7 ′. In other cases, Steps S2 to S4 are repeated until the second clutch engagement torque TCL2 falls within a predetermined range.

  In step S7 ′, it is determined whether or not the engine E has completely detonated. When the detonation has been completed, the process proceeds to step S8. Otherwise, steps S2 to S5 are repeated.

  In step S8, the engine torque control at the time of engine start is switched to motor torque control. In step S9, the second clutch CL2 is completely engaged.

  Next, the engagement control process of the first clutch CL1 will be described. Since the basic control flow is the same as in the first and second embodiments, only different points will be described. In the third embodiment, the gradient correction process in step S14 is different from the flowchart shown in FIG. Hereinafter, the gradient correction process according to the third embodiment will be described.

FIG. 17 is a flowchart illustrating the gradient correction process according to the third embodiment.
In step S301, it is determined whether or not the absolute value of the deviation between the target torque Tmg * of the motor generator MG and the actual torque Tmg is larger than the threshold value. If it is larger, the process proceeds to step S303. Therefore, the process proceeds to step S302, and the current gradient α of the first clutch CL1 is maintained.

  In step S303, it is determined whether or not the actual torque Tmg of motor generator MG is larger than target torque Tmg *. If it is larger, it is determined that the load acting on motor generator MG is excessive, and the process proceeds to step S305. On the other hand, when the actual torque Tmg is equal to or less than the target torque Tmg *, the load on the motor generator MG is insufficient and sufficient torque is not secured, so the process proceeds to step S304.

  In step S304, the gradient α of the engagement capacity of the first clutch CL1 is corrected more rapidly. If the increase gradient of the engagement capacity of the first clutch CL1 becomes steep, the load acting on the motor generator MG increases and the torque of the motor generator MG increases, so that excessive slip is not caused and stable engagement control is performed. Can be executed.

  In step S305, the gradient α of the engagement capacity of the first clutch CL1 is corrected more gently. When the increasing gradient of the engagement capacity of the first clutch CL1 becomes gentle, the load acting on the motor generator MG decreases and the torque of the motor generator MG decreases. Therefore, both the first clutch CL1 and the second clutch CL2 have an appropriate slip amount. And stable fastening control can be executed.

  Next, the operation based on the flowchart will be described. FIG. 18 is a time chart showing the engagement capacity control of the first clutch CL1 when an engine start request is made during traveling with a large target driving force tFto0.

  When an engine start request is made at time t1, precharge processing is executed. This precharge process is managed by a timer or the like, and it is determined that the precharge process is completed after a predetermined time has elapsed.

  At time t2, the engagement capacity of the first clutch CL1 is increased by the gradient α.

  When the actual torque Tmg of the motor generator MG increases above the target torque Tmg * at time t3, the gradient α is corrected so as to be gentle. Then, the load acting on motor generator MG is reduced and the torque of motor generator MG is reduced, so that it is possible to prevent the follow-up performance from being deteriorated in motor torque control at the time of engine start of motor generator MG.

  When the engagement capacity of the first clutch CL1 reaches TCL1h at time t4, it is held. As a result, the engine speed Ne passes through the low-speed resonance band quickly.

  At time t5, when the engine speed increases and the slip amount ΔN1 of the first clutch CL1 is less than the predetermined value a1 or the engine speed Ne is greater than the predetermined speed b1 representing the complete explosion determination, the engagement capacity holding is terminated. The process proceeds to a complete fastening process. At time t6, the complete fastening process is completed and the engine start is completed.

  As described above, in the configuration of the third embodiment, the following effects can be obtained in addition to (1) to (4) of the first embodiment.

  (7) When starting the engine E, the target torque Tmg * of the motor generator capable of starting the engine is set, and torque control is performed so that the motor generator MG becomes the target torque Tmg *. At this time, when the actual torque Tmg of the motor generator MG is larger than the target torque Tmg *, the predetermined gradient α is corrected to be gentle.

  Therefore, stable engagement control can be performed by controlling the gradient of the engagement capacity of the first clutch CL1 so that the actual torque Tmg of the motor generator MG follows the target torque Tmg *.

  Next, Example 4 will be described. Since the basic configuration is the same as that of the third embodiment, only different points will be described. In the third embodiment, the control based on the target torque Tmg * and the actual torque Tmg is performed as the gradient correction process. In contrast, the fourth embodiment is different in that the gradient correction process is performed based on the slip amount ΔN2 of the second clutch CL2.

FIG. 19 is a flowchart illustrating the gradient correction process according to the fourth embodiment.
In step S401, it is determined whether or not the absolute value of the deviation between the target slip amount ΔN2 * of the second clutch CL2 and the actual slip amount ΔN2 is larger than the threshold value. If larger, the process proceeds to step S403. Since it is well controlled, the process proceeds to step S402, and the current gradient α of the first clutch CL1 is maintained.

  In step S403, it is determined whether or not the actual slip amount ΔN2 of the second clutch CL2 is smaller than the target slip amount ΔN2 *, and if it is smaller, it is determined that the load acting on the motor generator MG is excessive and step S405 is performed. Proceed to On the other hand, when the actual slip amount ΔN2 is equal to or larger than the target slip amount ΔN2g *, it is a case where the load of the motor generator MG is insufficient and sufficient torque is not secured, and thus the process proceeds to step S404.

  In step S404, the gradient α of the engagement capacity of the first clutch CL1 is corrected more rapidly. When the increase gradient of the engagement capacity of the first clutch CL1 becomes steep, the load acting on the motor generator MG increases, and the number of revolutions of the motor generator MG is suppressed. Can be executed.

  In step S405, the gradient α of the engagement capacity of the first clutch CL1 is corrected more gently. When the increasing gradient of the engagement capacity of the first clutch CL1 becomes gentle, the load acting on the motor generator MG decreases and the rotation speed of the motor generator MG increases, so that the second clutch CL2 can secure an appropriate slip amount, Stable fastening control can be executed.

  Next, the operation based on the flowchart will be described. FIG. 20 is a time chart showing engagement capacity control of the first clutch CL1 when an engine start request is made during traveling with a large target driving force tFto0.

  When an engine start request is made at time t1, precharge processing is executed. This precharge process is managed by a timer or the like, and it is determined that the precharge process is completed after a predetermined time has elapsed.

  At time t2, the engagement capacity of the first clutch CL1 is increased by the gradient α.

  When the actual slip amount ΔN2 of the second clutch CL2 becomes smaller than the target slip amount ΔN2 * at time t3, the gradient α is corrected so as to be gentle. Then, the load acting on the motor generator MG is reduced and the rotational speed of the motor generator MG is increased, so that the second clutch CL2 can secure an appropriate slip amount and stable engagement control can be executed.

  When the engagement capacity of the first clutch CL1 reaches TCL1h at time t4, it is held. As a result, the engine speed Ne passes through the low-speed resonance band quickly.

  At time t5, when the engine speed increases and the slip amount ΔN1 of the first clutch CL1 is less than the predetermined value a1 or the engine speed Ne is greater than the predetermined speed b1 representing the complete explosion determination, the engagement capacity holding is terminated. The process proceeds to a complete fastening process. At time t6, the complete fastening process is completed and the engine start is completed.

  As described above, in the configuration of the fourth embodiment, the following effects can be obtained in addition to (1) to (4) of the first embodiment.

  (8) When starting the engine E, the target torque Tmg * of the motor generator MG capable of starting the engine is set, and torque control is performed so that the motor generator MG becomes the target torque Tmg *. At this time, when the actual slip amount ΔN2 of the second clutch CL2 is smaller than the target slip amount ΔN2 *, the predetermined gradient is corrected to be gentle.

  That is, when actual slip amount ΔN2 is smaller than target slip amount ΔN2 *, it can be determined that the load acting on motor generator MG is excessive. At this time, the gradient α of the engagement capacity of the first clutch CL1 is more gently corrected to reduce the load acting on the motor generator MG and increase the rotation speed of the motor generator MG. Therefore, the second clutch CL2 An appropriate slip amount can be secured and stable fastening control can be executed.

  On the other hand, when the actual slip amount ΔN2 is equal to or larger than the target slip amount ΔN2g *, it can be determined that the load of the motor generator MG is insufficient and sufficient torque is not secured. At this time, the load α acting on the motor generator MG increases by correcting the gradient α of the engagement capacity of the first clutch CL1 more rapidly, thereby suppressing the number of revolutions of the motor generator MG, leading to excessive slip. And stable fastening control can be executed.

  Next, Example 5 will be described. Since the basic configuration is the same as that of the third embodiment, only different points will be described. In the third embodiment, the control based on the target torque Tmg * and the actual torque Tmg is performed as the gradient correction process. On the other hand, the fifth embodiment is different in that gradient correction processing is performed based on the slip amount ΔN1 of the first clutch CL1.

FIG. 21 is a flowchart illustrating the gradient correction process according to the fifth embodiment.
In step S501, it is determined whether or not the absolute value of the deviation between the target slip amount ΔN1 * of the first clutch CL1 and the actual slip amount ΔN1 is larger than a threshold value. If larger, the process proceeds to step S503. Since it is well controlled, the process proceeds to step S502, and the current gradient α of the first clutch CL1 is maintained.

  In step S503, it is determined whether the actual slip amount ΔN1 of the first clutch CL1 is smaller than the target slip amount ΔN1 *. If it is smaller, it is determined that the engagement capacity of the first clutch CL1 is too large, and the process proceeds to step S505. On the other hand, when the actual slip amount ΔN1 is equal to or larger than the target slip amount ΔN1g *, it is determined that the engagement capacity of the first clutch CL1 is too small, and the process proceeds to step S504.

  In step S504, the gradient α of the engagement capacity of the first clutch CL1 is corrected more rapidly. When the rising gradient of the engagement capacity of the first clutch CL1 becomes steep, the load acting on the motor generator MG increases, suppressing the rotation speed of the motor generator MG and increasing the engine rotation speed, thereby causing excessive slip. And stable fastening control can be executed.

  In step S505, the gradient α of the engagement capacity of the first clutch CL1 is corrected more gently. When the increase gradient of the engagement capacity of the first clutch CL1 becomes gentle, the load acting on the motor generator MG decreases, and the rotation speed of the motor generator MG is increased and the increase in the engine rotation speed is suppressed. CL1 can secure an appropriate slip amount and can perform stable fastening control.

  Next, the operation based on the flowchart will be described. FIG. 22 is a time chart showing engagement capacity control of the first clutch CL1 when an engine start request is made during traveling with a large target driving force tFto0.

  When an engine start request is made at time t1, precharge processing is executed. This precharge process is managed by a timer or the like, and it is determined that the precharge process is completed after a predetermined time has elapsed.

  At time t2, the engagement capacity of the first clutch CL1 is increased by the gradient α.

  When the actual slip amount ΔN1 of the first clutch CL1 decreases below the target slip amount ΔN1 * at time t3, the gradient α is corrected so as to be gentle. Then, the load acting on the motor generator MG is reduced to increase the rotation speed of the motor generator MG and to suppress the increase of the engine rotation speed, so that the first clutch CL1 can secure an appropriate slip amount and stably engages. Control can be executed.

  When the engagement capacity of the first clutch CL1 reaches TCL1h at time t4, it is held. As a result, the engine speed Ne passes through the low-speed resonance band quickly.

  At time t5, when the engine speed increases and the slip amount ΔN1 of the first clutch CL1 is less than the predetermined value a1 or the engine speed Ne is greater than the predetermined speed b1 representing the complete explosion determination, the engagement capacity holding is terminated. The process proceeds to a complete fastening process. At time t6, the complete fastening process is completed and the engine start is completed.

  As described above, in the configuration of the fifth embodiment, the following effects can be obtained in addition to (1) to (4) of the first embodiment.

  (9) When starting the engine E, the target torque Tmg * of the motor generator MG capable of starting the engine is set, and torque control is performed so that the motor generator MG becomes the target torque Tmg *. At this time, when the actual slip amount ΔN1 of the first clutch CL1 is smaller than the target slip amount ΔN1 *, the predetermined gradient is corrected to be gentle.

  That is, when actual slip amount ΔN1 is smaller than target slip amount ΔN1 *, it can be determined that the load acting on motor generator MG is excessive. At this time, by correcting the engagement capacity gradient α of the first clutch CL1 more gently, the load acting on the motor generator MG is reduced, the rotational speed of the motor generator MG is increased, and the engine rotational speed is increased. Therefore, the first clutch CL1 can secure an appropriate slip amount and can perform stable engagement control.

  On the other hand, when the actual slip amount ΔN1 is equal to or greater than the target slip amount ΔN1 *, it can be determined that the motor generator MG is insufficiently loaded and sufficient torque is not secured. At this time, the load α acting on the motor generator MG increases by correcting the gradient α of the engagement capacity of the first clutch CL1 more rapidly, thereby suppressing the rotation speed of the motor generator MG and increasing the engine rotation speed. Therefore, stable slip control can be executed without causing excessive slip.

  As mentioned above, although each Example 1-5 was demonstrated, you may implement combining not only said each Example but the structure of each Example suitably. For example, since the first embodiment and the second embodiment are common in that the motor rotation speed control is executed at the time of starting the engine as a precondition, both the gradient correction processes of the first embodiment and the second embodiment are executed. The gradient correction amount calculated from both may be added and corrected by appropriate gain setting.

  In addition, since the third to fifth embodiments are common in that motor torque control is executed at the time of engine start as a precondition, the gradient correction processing of each of the third to fifth embodiments is executed and calculated. The three gradient correction amounts may be added and corrected by appropriate gain settings.

  Here, the present invention is preliminarily configured with an engine, a motor generator, a first fastening element interposed between the engine and the motor generator, and a motor generator and drive wheels. A second fastening element, a torque capacity required to raise the engine to a startable rotational speed, and a holding fastening capacity for setting a holding fastening capacity of the first fastening element based on a torque capacity required for acceleration of the vehicle A setting means; a second fastening element control means for slip-controlling the second fastening element when starting the engine; and a fastening capacity of the first fastening element at a predetermined gradient when starting the engine. And an engine starting holding means for holding in a state of being raised to the holding fastening capacity, what is finally achieved is a motor generator of the second fastening element Speed has only to comprise a gradient correction means for correcting the slope to be higher than the rotational speed of the driving wheel of the second coupling element.

  When the engine is running, the first clutch CL1 and the second clutch CL2 are both controlled to slip. At this time, the slip amount of each clutch and the operating state of motor generator MG are closely related.

  Here, a necessary condition for achieving a smooth engine start is that the second clutch CL2 has a slip state in which the number of revolutions on the motor generator side is higher than that on the drive wheel side. Regardless of whether the engine speed is controlled or not, there is no difference.

  In order to achieve this state, the operating state of the motor generator MG must be appropriate. Therefore, there is no choice but to adjust the driving force of the motor generator MG itself or adjust the load acting on the motor generator MG as appropriate. Therefore, in each of the embodiments, the one that controls the drive state of the motor generator MG itself and the one that controls the load state acting on the motor generator MG are proposed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram illustrating a rear-wheel drive hybrid vehicle according to a first embodiment. FIG. 3 is a control block diagram illustrating an arithmetic processing program in the integrated controller according to the first embodiment. It is a figure which shows an example of the target driving force map used for target driving force calculation in the target driving force calculating part of FIG. It is a figure which shows the EV-HEV selection map used for selection of the target mode in the mode selection part of FIG. It is a figure which shows an example of the target charging / discharging amount map used for the calculation of target charging / discharging electric power in the target charging / discharging calculating part of FIG. 6 is a flowchart showing a second clutch engagement control process at the time of engine start according to the first embodiment. It is a time chart at the time of performing fastening control of the 2nd clutch in a comparative example. 6 is a time chart when performing engagement control of a second clutch in the first embodiment. 4 is a flowchart illustrating a first clutch engagement control process according to the first embodiment. 3 is a flowchart illustrating a gradient correction process in the first embodiment. 6 is a time chart illustrating a first clutch engagement control process when the target driving force is small in the first embodiment. 6 is a time chart showing a first clutch engagement control process when the target driving force in Example 1 is large. 10 is a flowchart illustrating a gradient correction process in the second embodiment. 6 is a time chart showing a first clutch engagement control process when the target driving force in Example 2 is large. FIG. 10 is a control block diagram illustrating an arithmetic processing program in an integrated controller according to a third embodiment. 12 is a flowchart showing a second clutch engagement control process at the time of engine start according to a third embodiment. 12 is a flowchart illustrating a gradient correction process in the third embodiment. 12 is a time chart illustrating a first clutch engagement control process when the target driving force is large in the third embodiment. 10 is a flowchart illustrating a gradient correction process in the fourth embodiment. 12 is a time chart illustrating a first clutch engagement control process when the target driving force is large in the fourth embodiment. 10 is a flowchart illustrating a gradient correction process in the fifth embodiment. 10 is a time chart showing a first clutch engagement control process when the target driving force in Example 5 is large.

Explanation of symbols

E engine
FW flywheel
CL1 1st clutch
MG motor generator
CL2 2nd clutch
AT automatic transmission
PS propeller shaft
DF differential
DSL left drive shaft
DSR right drive shaft
RL Left rear wheel (drive wheel)
RR Right rear wheel (drive wheel)
FL Left front wheel
FR Right front wheel 1 Engine controller 2 Motor controller 3 Inverter 4 Battery 5 First clutch controller 6 First clutch hydraulic unit 7 AT controller 8 Second clutch hydraulic unit 9 Brake controller 10 Integrated controller 24 Brake hydraulic sensor
100 Target driving force calculator
200 Mode selection section
300 Target charge / discharge calculator
400 Operating point command section
500 Shift control

Claims (10)

Engine,
A motor generator connected to the drive wheels;
A first fastening element interposed between the engine and the motor generator;
The torque capacity required to raise the engine to the startable speed within the target time, and the deviation between the reached motor generator speed converted from the vehicle speed reached after the target time and the startable speed of the engine Holding fastening capacity setting means for setting the holding fastening capacity based on the torque capacity required to increase the engine speed within the target start time ;
When starting the engine, fastening capacity holding means for raising and holding the fastening capacity of the first fastening element to the holding fastening capacity with a predetermined gradient;
A control apparatus for a hybrid vehicle, comprising: In the hybrid vehicle control device according to claim 1,
The control apparatus for a hybrid vehicle , wherein the predetermined gradient is a maximum response gradient of the first fastening element . In the control apparatus of the hybrid vehicle according to claim 1 or 2 ,
The fastening capacity holding means continues the holding until the slip amount of the first fastening element is equal to or less than a predetermined value or the rotational speed of the engine is equal to or higher than a startable rotational speed. apparatus. In the hybrid vehicle control device according to claim 3 ,
A hybrid vehicle is provided with complete fastening means for raising the maximum fastening gradient of the first fastening element to the full fastening capacity of the first fastening element when holding by the engine starting holding means is finished . Control device. In the hybrid vehicle control device according to any one of claims 1 to 4 ,
A second fastening element interposed between the motor generator and the drive wheel;
When starting the engine, second fastening element control means for slip-controlling the second fastening element;
When starting the engine, an engine that sets a target rotational speed obtained by adding a predetermined rotational speed to the driving wheel side rotational speed of the second fastening element and controls the rotational speed so that the motor generator becomes the target rotational speed A starting speed control means;
Gradient correction means for correcting the predetermined gradient to be gentle when the actual rotational speed of the motor generator is smaller than the target rotational speed;
Control apparatus for a hybrid vehicle, wherein a is provided. In the hybrid vehicle control device according to any one of claims 1 to 4 ,
A second fastening element interposed between the motor generator and the drive wheel;
When starting the engine, second fastening element control means for slip-controlling the second fastening element;
When starting the engine, an engine that sets a target rotational speed obtained by adding a predetermined rotational speed to the driving wheel side rotational speed of the second fastening element and controls the rotational speed so that the motor generator becomes the target rotational speed A starting speed control means;
Slope correction means for correcting the predetermined slope to be gentle when the slip amount of the first fastening element is smaller than a predetermined value;
Control apparatus for a hybrid vehicle, wherein a is provided. In the hybrid vehicle control device according to any one of claims 1 to 4 ,
When starting the engine, engine starting torque control means for setting a target torque of the motor generator capable of starting the engine and controlling the torque so that the motor generator becomes the target torque;
When the actual torque of the motor generator is larger than the target torque, a gradient correction unit that corrects the predetermined gradient so as to be gentle,
Control apparatus for a hybrid vehicle, wherein a is provided. In the hybrid vehicle control device according to any one of claims 1 to 4 ,
A second fastening element interposed between the motor generator and the drive wheel;
When starting the engine, second fastening element control means for slip-controlling the second fastening element;
When starting the engine, engine starting torque control means for setting a target torque of the motor generator capable of starting the engine and controlling the torque so that the motor generator becomes the target torque;
Slope correction means for correcting the predetermined slope to be gentle when the slip amount of the second fastening element is smaller than a predetermined value;
Control apparatus for a hybrid vehicle, wherein a is provided. In the hybrid vehicle control device according to any one of claims 1 to 4 ,
When starting the engine, engine starting torque control means for setting a target torque of the motor generator capable of starting the engine and controlling the torque so that the motor generator becomes the target torque;
Slope correction means for correcting the predetermined slope to be gentle when the slip amount of the first fastening element is smaller than a predetermined value;
Control apparatus for a hybrid vehicle, wherein a is provided. An engine,
A motor generator;
A first fastening element interposed between the engine and the motor generator;
A second fastening element interposed between the motor generator and the drive wheel;
Holding torque capacity setting means for setting a torque capacity required for pulling up the engine to a startable engine speed and a torque capacity required for accelerating the vehicle;
When starting the engine, second fastening element control means for slip-controlling the second fastening element;
When starting the engine, an engine start holding means for holding the first fastening element in a state in which the fastening capacity of the first fastening element is raised to the holding fastening capacity with a predetermined gradient;
Gradient correction means for correcting the gradient so that the rotation speed of the second fastening element on the motor generator side is higher than the rotation speed of the second fastening element on the drive wheel side;
Control apparatus for a hybrid vehicle comprising the.

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