JP5566582B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle control device that switches between an electric vehicle traveling mode and a hybrid vehicle traveling mode by connecting and disconnecting a friction clutch.

Conventionally, as a travel mode, a hybrid vehicle having an electric vehicle travel mode with a friction clutch disconnected and a hybrid vehicle travel mode with a friction clutch fastened is known. The driving force control in this hybrid vehicle calculates the timing at which the stepped transmission starts automatic shifting, gradually decreases the torque assist by the motor torque by the motor generator before the shifting starts, and the friction clutch is disengaged at the time of shifting. The torque disparity generated when the torque disappears is reduced, and the gradient of the torque change is made gentle to reduce the shock at the time of shifting (see, for example, Patent Document 1).
JP 2001-315552 JP

  However, the conventional hybrid vehicle driving force control is not a control that takes into account the change in the clutch capacity of the friction clutch. Therefore, if the driving force demand increases during traveling in the electric vehicle traveling mode, the friction clutch Is engaged and the engine is connected to shift to the hybrid vehicle running mode, but this scene exists even during the shift of the automatic transmission, and if the clutch capacity change (partial to complete engagement) is not taken into account, the clutch is connected. There was a problem that sometimes shock occurred.

  The present invention has been made paying attention to the above-mentioned problem. By taking into account the change in clutch capacity and controlling a highly responsive motor in the drive system, the smooth occurrence of shocks due to clutch engagement / disconnection is suppressed. It is an object of the present invention to provide a control device for a hybrid vehicle that can perform driving force control.

In order to achieve the above object, the hybrid vehicle control apparatus of the present invention comprises a drive system in which a clutch is interposed between the engine and the motor, and a transmission is installed between the motor and the drive wheel, and the clutch is disconnected. A transmission input for detecting an actual transmission input rotational speed of the transmission, and a driving force control means for controlling an output torque of the motor. A rotation speed detecting means is provided.
When the driving force demand increases during traveling in the electric vehicle traveling mode, the driving force control means engages the clutch in a half-clutch state, connects the stopped engine, and starts the motor. When starting the engine as a motor and shifting to the hybrid vehicle travel mode, the engine from the engine via the clutch is based on the engine speed, the clutch engagement state, and the transmission gear ratio state. calculating a target transmission input rotational speed which is the input rotating speed estimated value for the transmission, the differential value for calculating a difference value by subtracting the rotational speed the target transmission input from said by the motor for performing speed control the actual transmission input rotational speed a calculation unit, the difference value is determined to exceed zero During multiplies the gain to increase the normal rate of increase of the output torque to the motor torque when performing speed control to set the motor compensation torque, motor compensation torque for outputting a command to obtain a motor compensation torque set to the motor And an output unit.

Therefore, in the hybrid vehicle control apparatus of the present invention, when the driving force demand increases during driving in the electric vehicle driving mode in the driving force control means, the engine is engaged and stopped in the half-clutch state. Are connected, the engine is started using the motor as an engine start motor, and the hybrid vehicle travel mode is entered . At this time, based on the engine speed, the clutch engagement state, and the transmission gear ratio state , a target transmission input rotation speed that is an estimated input rotation speed from the engine to the transmission via the clutch is calculated . When the difference value obtained by subtracting the target transmission input rotation speed from the actual transmission input rotation speed by the motor that performs the rotation speed control is calculated and it is determined that the difference value exceeds zero, the rotation speed control is performed. The motor compensation torque is set by multiplying the normal motor torque by a gain for increasing the increase rate of the output torque, and a command for obtaining the set motor compensation torque is output to the motor .
That is, the change direction of the input rotational speed of the transmission is prefetched by comparing the target transmission input rotational speed and the actual transmission input rotational speed in consideration of the clutch engagement state and the transmission gear ratio state. And, by compensating the output torque of the motor with high control response, the change in the input rotational speed of the transmission is suppressed in advance, and accordingly, the occurrence of the vehicle speed fluctuation (change in the output rotational speed of the transmission) unintended by the user is generated. Depressing action.
As a result, by taking into account changes in the clutch capacity and controlling a highly responsive motor in the drive system, it is possible to perform smooth driving force control that suppresses the occurrence of shock due to clutch engagement / disengagement.

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

FIG. 1 is an overall system diagram illustrating an FF hybrid vehicle (an example of a hybrid vehicle) to which the control device of the first embodiment is applied. In FIG. 1, the strong electric system is indicated by a thin broken line, the weak electric system is indicated by a thin solid line, the power system is indicated by a thick solid line, and the hydraulic circuit is indicated by a thick dashed line.

  As shown in FIG. 1, the FF hybrid vehicle of the first embodiment includes a CPU 101, an auxiliary battery 102, a brake actuator 201, a mechanical brake 202, a high-power battery 301, an inverter 302, and a motor generator 303 (motor). Engine 304, transmission 305, clutch 306, accelerator sensor 401, brake sensor 402, DC / DC converter 403, inter-vehicle sensor 404 (inter-vehicle distance detecting means), and navigation system 405 (terrain information acquiring means) A mode selection switch 406 (mode selection means), a motor speed sensor 407 (transmission input speed detection means), a vehicle speed sensor 408, an engine speed sensor 409 (engine speed detection means), and a clutch stroke sensor 410.

  The CPU 101 monitors the state of the high-power battery 301, calculates the input / output possible electric energy according to the battery SOC, the battery temperature, and the battery deterioration state, and controls the inverter 302 based on this to generate the motor generator 303 ( And the engine 304 is controlled (including driving force distribution).

  The CPU 101 considers the regenerative braking force by the motor generator 303 and transmits a braking force calculation command value (including front / rear braking force distribution) generated by the mechanical brake 202 to the brake actuator 201.

  The CPU 101 controls a clutch 306 for connecting / disconnecting the motor generator 303 and the engine 304, and selects “HEV mode (fastening the clutch 306 and using the motor generator 303 and engine 304 as a power source)”, “EV mode (clutch 306 Is switched to “ENG mode (clutch 306 is engaged and only engine 304 is used as a power source)”.

  The CPU 101 collects the inter-vehicle distance and size between the host vehicle and the preceding vehicle (obstacle) based on a signal from the inter-vehicle sensor 404, and applies it to the control as necessary. The own vehicle speed is basically determined based on the number of revolutions of the motor generator 303, and the detected vehicle speed fluctuation state and average vehicle speed data are stored and updated.

  The CPU 101 monitors the carry-out power from the auxiliary battery 102 and applies this to the control as an “auxiliary machine load”.

  The auxiliary battery 102 serves to provide an operating power source for the CPU 101. In this system, power is supplied by a DC / DC converter 403 that uses a high-power battery 301 as a power source.

  The brake actuator 201 receives a braking force calculation command value to be generated by the mechanical brake 202 calculated by the CPU 101 based on the amount of depression (stroke) of the driver detected by the brake sensor 402, and in response thereto, the mechanical brake Apply the necessary hydraulic pressure to 202.

  The mechanical brake 202 generates a braking force according to the hydraulic pressure generated by the brake actuator 201.

  The high-power battery 301 assists vehicle travel by supplying electric power to the motor generator 303 (for driving) via the inverter 302, and transmits electric power generated by the motor generator 303 via the inverter 302. Has the role of collecting.

  The inverter 302 is directly controlled by the CPU 101. The electric energy of the high-power battery 301 is supplied to the motor generator 303 according to the generated torque and the rotational speed of the engine 304, and the electric energy generated by operating the motor generator 303 is returned to the high-power battery 301.

  The motor generator 303 generates drive torque independently when the vehicle speed is low. Further, when the vehicle speed is high, the driving torque of the engine 304 is assisted. Furthermore, it has a function of generating electric energy by generating power (regenerative braking) during deceleration and returning this electric energy to the high-power battery 301 via the inverter 302.

  The engine 304 is directly controlled by the CPU 101. Specifically, when the vehicle speed is high, torque is generated to drive the vehicle (when the vehicle speed is low, the motor travels, so no control is necessary. For this reason, control that does not start is applied). .

  The transmission 305 has a function of transmitting the driving force generated by the motor generator 303 and the engine 304 to the driving wheels, and a function of transmitting the kinetic energy of the driving wheels to the motor generator 303 when regenerative braking is performed. Note that it may be a stepped AT or a continuously variable transmission (CVT). The proposed system also includes a “rotational speed sensor” that detects the input rotational speed and the output rotational speed.

  The clutch 306 is connected when the torque generated by the engine 304 is transmitted to the motor generator 303 and the transmission 305, and is disconnected when traveling only by the motor generator 303 ("EV mode").

  The accelerator sensor 401 transmits to the CPU 101 the stroke amount of the accelerator pedal that the driver has depressed during acceleration.

  The brake sensor 402 transmits to the CPU 101 the stroke amount of the brake pedal that the driver has depressed during deceleration.

  The DC / DC converter 403 converts the energy from the high voltage battery 301 into about 12 V and supplies it to the auxiliary battery 102. That is, it has the same function as an alternator in a conventional engine vehicle.

  The inter-vehicle sensor 404 collects the distance from the vehicle in front of the host vehicle (or an obstacle) using a radar or the like, and inputs information obtained thereby to the CPU 101.

  The navigation system 405 has a GPS (Global Positioning System) built-in, and detects information such as signals on traffic routes, intersections, toll booths, traffic jams, distances from current locations to traffic jams, grades, and speed limits. The information obtained thereby is transmitted to the CPU 101.

  The mode selection switch 406 is a switch that allows the user to arbitrarily select a travel mode. As the selection mode, “normal mode” which is a normal specification, “sport mode” in which the driving torque is higher than normal, “eco mode” in which fuel consumption performance is improved than normal, and the like can be set. The set mode information is transmitted to the CPU 101.

  The motor rotation speed sensor 407 detects the input rotation speed of the transmission 303 and transmits information obtained thereby to the CPU 101.

  The vehicle speed sensor 408 detects the output rotation speed (= vehicle speed) of the transmission 303 and transmits information obtained thereby to the CPU 101.

  The engine speed sensor 409 detects the speed of the engine 304 and transmits information obtained thereby to the CPU 101.

  The clutch stroke sensor 410 detects the stroke of the hydraulic actuator of the clutch 306, and transmits the clutch interval information obtained thereby to the CPU 101.

FIG. 2 is a flowchart showing the flow of driving force control processing by the motor generator 303 executed by the CPU 101 of the first embodiment (driving force control means). FIG. 3 is a characteristic diagram showing the relationship of the clutch gain with respect to the clutch interval of the clutch 306 used in the driving force control process of the first embodiment. FIG. 4 is a characteristic diagram showing the relationship of the gear ratio with respect to an example of the AT gear stage that sets the gear ratio of the transmission 305 used in the driving force control process of the first embodiment. FIG. 5 is a diagram illustrating an example of a shift line map in the transmission 305 of the first embodiment. FIG. 6 is a characteristic diagram illustrating the relationship of the compensation torque gain with respect to the distance from the preceding vehicle used in the driving force control process of the first embodiment. FIG. 7 is a characteristic diagram illustrating the relationship of the compensation torque gain with respect to the gradient used in the driving force control process of the first embodiment. FIG. 8 is a characteristic diagram illustrating the relationship of the compensation torque gain with respect to “eco mode”, “normal mode”, and “sport mode” selected by the user, which is used in the driving force control process of the first embodiment. Hereinafter, each step of the flowchart of FIG. 2 will be described. In step S20, the vehicle speed VSP from the vehicle speed sensor 408 and the accelerator opening APO from the accelerator sensor 401 are read, and the process proceeds to step S21.

In step S21, following the reading of the vehicle speed VSP and the accelerator opening APO in step S20, a region where the operating point based on the vehicle speed VSP and the accelerator opening APO exists on the EV-HEV switching map characteristics is searched, and the process proceeds to step S22. Transition.
Here, as the EV-HEV switching map characteristics, there are three characteristics of “eco-mode characteristics”, “normal mode characteristics”, and “sport mode characteristics”, and map characteristics corresponding to the mode selected by the user are used. Searched.

  In step S22, following the EV-HEV switching map search in step S21, when the operating point based on the vehicle speed VSP and accelerator opening APO crosses the EV → HEV switching line, the mode transition from EV mode to HEV mode begins. It is determined whether (= when engine start command is output). If YES (when transition from EV to HEV mode starts), the process proceeds to step S23, and if NO (when EV mode or HEV mode is fixed) Returns to step S20.

In step S23, following the determination that the transition from EV to HEV mode is started in step S22, the clutch interval S detected by the clutch stroke sensor 410 and the clutch with respect to the clutch interval S of the clutch 306 shown in FIG. The clutch gain α is set using the relational characteristic of the gain α, and the process proceeds to step S24 (clutch gain setting unit).
Here, as shown in FIG. 3, the relational characteristic of the clutch gain α with respect to the clutch interval S is that α = 1 when the clutch interval S is in the clutch engagement region of S = 0 to S1, and S = S1 to S2 Α = 1 to α = 0 in the half-clutch region, and is given by a value of α = 0 in the clutch release region of S ≧ S2. That is, when the clutch 306 shifts from disengagement to engagement, the clutch gain α changes from α = 0 to α = 1. Conversely, when the clutch 306 shifts from engagement to disengagement, the clutch gain α is , Α = 1 to α = 0.

In step S24, following the setting of the clutch gain α with respect to the clutch interval S in step S23, a gear ratio gradient di / dt, which is a change gradient of the gear ratio i in the transmission 305, is set, and the process proceeds to step S25 (speed ratio). Gradient setting part).
Here, when the AT gear stage is fixed at any one of the first gear to the seventh gear, the change of the gear ratio i with respect to the AT gear stage in the transmission 305 (forward 7-speed automatic transmission) shown in FIG. The gear ratio gradient di / dt is given by di / dt = 1. Further, when the driving point based on the vehicle speed VSP and the accelerator opening APO crosses the downshift line or the upshift line of the shift map shown in FIG. 5, the type of shift (upshift, downshift) and the estimated value of the shift progress speed Thus, the gear ratio gradient di / dt is given by di / dt> 1 (during downshift) and di / dt <1 (during upshift).

In step S25, following the setting of the gear ratio with respect to the AT gear stage in step S24, the engine speed Ne from the engine speed sensor 409, the clutch gain α set in step S23, and the step S24 are set. The target transmission input rotational speed NT ^* is calculated using the gear ratio gradient di / dt, and the process proceeds to step S26 (target transmission input rotational speed calculation unit).
Where the target transmission input speed NT ^* is
NT ^* = Ne x α x di / dt
It is calculated by the following formula.
That is, target transmission input speed NT ^* is a value that converges to actual transmission input speed NT as clutch 306 shifts from disengagement to engagement.

In step S26, following the calculation of the target transmission input speed NT ^* in step S25, a difference value ΔNT obtained by subtracting the target transmission input speed NT ^* from the actual transmission input speed NT obtained by the motor speed sensor 407 is obtained. Calculate and move to step S27.

  In step S27, following the calculation of the difference value ΔNT in step S26, it is determined whether or not the difference value ΔNT is ΔNT> 0. If YES (ΔNT> 0), the process proceeds to step S28, and NO (ΔNT If ≦ 0), the process proceeds to step S34.

In step S28, following the determination that ΔNT> 0 in step S27, the compensation torque gain characteristic with respect to the distance L from the preceding vehicle from the inter-vehicle sensor 404 and the distance L from the preceding vehicle shown in FIG. The compensation torque gain G1 is set, and the process proceeds to step S29 (compensation torque gain setting unit).
Here, the compensation torque gain characteristic shown in FIG. 6 is obtained when the compensation torque gain G1 is given as a maximum value in a region where the distance L to the preceding vehicle is L1 or more and the interval L from the preceding vehicle is less than L1. A compensation torque gain G1 is set to a smaller value as the distance L with the preceding vehicle becomes smaller, and the acceleration limitation is strengthened.

In step S29, following the setting of the compensation torque gain G1 for the distance L from the preceding vehicle in step S28, the compensation torque gain characteristic using the topographic information from the navigation system 405 and the compensation torque gain characteristic for the gradient degree θ shown in FIG. The gain G2 is set, and the process proceeds to step S30 (compensation torque gain setting unit).
Here, in the compensation torque gain characteristic shown in FIG. 7, a flat road having a slope of 0 is used as a reference value of the compensation torque gain G2, and the slope of the slope θ on the uphill road indicates a steep slope uphill. The compensation torque gain G2 is given as a smaller value as the slope degree θ indicates a steep slope downhill on the downhill road.

In step S30, following the setting of the compensation torque gain G2 for the gradient degree θ in step S29, the selected mode information from the mode selection switch 406 and the compensation torque gain characteristic for the user selection mode shown in FIG. The compensation torque gain G3 is set, and the process proceeds to step S31 (compensation torque gain setting unit).
Here, the compensation torque gain characteristic shown in FIG. 8 is based on the reference value of the compensation torque gain G3 when “normal mode” is selected, and the compensation torque gain G3 when “sport mode” is selected compared to when “normal mode” is selected. The compensation torque gain G3 when “Eco mode” is selected is set to a larger value than when “Normal mode” is selected.

In step S31, following the setting of the compensation torque gain G3 for the user selection mode in step S30, the MG compensation torque (acceleration) is set using the normal MG torque and each compensation torque gain G1, G2, G3, etc. Move on to S32.
Here, in calculating the MG compensation torque, a unit state compensation torque gain G4 and various fail-safe gains G5 are set in addition to the compensation torque gains G1, G2, and G3.
The unit state compensation torque gain G4 is set according to each unit state in consideration of the temperature of the high-power battery 301, the inverter 302, the motor generator 303, the engine 304, the transmission 305, the clutch 306, and the battery SOC.
The various failsafe gains G5 are output torque limit gains set in the “restricted travel mode” corresponding to each ECU failure.
And MG compensation torque is
MG compensation torque = normal MG torque x G1 x G2 x G3 x G4 x G5
Set by the following formula.

  In step S32, following the setting of the MG compensation torque in step S31, a control command for obtaining the set MG compensation torque is output to the motor generator 303, and the process proceeds to step S33 (motor compensation torque output unit).

  In step S33, following the output of the MG compensation torque in step S32 or the normal MG torque output in step S34, it is determined whether or not the transition from the EV mode to the HEV mode is completed, and YES (HEV mode In the case of NO (in the middle of transition to the HEV mode), the process returns to step S23.

  In step S34, following the determination that ΔNT ≦ 0 in step S27, a control command for obtaining normal MG torque is output to motor generator 303, and the process proceeds to step S33.

Next, the operation will be described.
The operation of the control apparatus for the FF hybrid vehicle according to the first embodiment will be described by dividing it into “driving force control operation by accelerator depression operation during EV traveling” and “MG compensation torque gain setting operation”.

[Driving force control action by depressing the accelerator during EV travel]
FIG. 9 shows changes in the actual transmission input rotational speed and the target transmission input rotational speed in the traveling scene in which the engine start and the downshift proceed simultaneously by the accelerator depressing operation during EV traveling in the control device for the FF hybrid vehicle of the first embodiment. It is a time chart which shows. FIG. 10 shows the engine rotation in the driving scene in which the control mode of the FF hybrid vehicle of the first embodiment transits to the EV mode by performing the accelerator return operation after temporarily transiting to the HEV mode by the accelerator depressing operation during the EV running. 4 is a time chart showing characteristics of a motor speed, a motor generator rotational speed, a transmission input rotational speed, an AT shift stage, a required torque, and a clutch engagement state.

  While traveling, the process proceeds from step S20 to step S21 to step S22 in the flowchart of FIG. 2, and at step S22, the operating point depending on the vehicle speed VSP and the accelerator opening APO exists in the EV mode region or HEV mode region. However, as long as the travel mode is fixed, the flow from step S20 to step S21 to step S22 is repeated. Note that when traveling in the EV mode, the clutch 306 is released, and the motor generator 303 is controlled in accordance with a control rule in the EV mode. Further, when traveling in the HEV mode, the clutch 306 is engaged, and the operation of the engine 304 and the motor generator 303 is controlled according to the control law in the HEV mode.

Then, in step S22, when the mode transition from the EV mode to the HEV mode is started by the driving point based on the vehicle speed VSP and the accelerator opening APO crossing the EV → HEV switching line, the step S23 → The process proceeds from step S24 to step S25. In step S25, the engine speed Ne from the engine speed sensor 409, the clutch gain α set in step S23, and the gear ratio gradient di / set in step S24. Using dt, the target transmission input speed NT ^* is calculated.

Then, the process proceeds from step S25 to step S26, and in step S26, a difference value ΔNT obtained by subtracting the target transmission input rotational speed NT ^* from the actual transmission input rotational speed NT obtained by the motor rotational speed sensor 407 is calculated. If it is determined in the next step S27 that the difference value ΔNT is ΔNT> 0, in the flowchart of FIG. 2, the process proceeds from step S28 → step S29 → step S30 → step S31 → step S32, and in step S32 Then, a control command for obtaining the MG compensation torque set in step S31 is output to motor generator 303.

  Then, while it is determined in step S27 that the difference value ΔNT is ΔNT> 0, in other words, while a change in the input rotational speed of the transmission 395 is predicted, step S23 → step S24 → step S25 → step The flow from S26 → step S27 → step S28 → step S29 → step S30 → step S31 → step S32 → step S33 is repeated, and a control command for obtaining the MG compensation torque set in step S31 is output to the motor generator 303. to continue.

  When it is determined in step S27 that the difference value ΔNT is ΔNT ≦ 0 and the input rotation speed of the transmission 395 does not change, the process proceeds from step S27 to step S34 in the flowchart of FIG. A control command for obtaining normal MG torque is output to motor generator 303. While the difference value ΔNT is determined to be ΔNT ≦ 0 in step S27, the flow of steps S23 → step S24 → step S25 → step S26 → step S27 → step S34 → step S33 is repeated. The control command for obtaining the normal MG torque continues to be output to the motor generator 303.

  For example, when the driving force demand increases during traveling in the EV mode, the clutch 306 is engaged in a half-clutch state, the engine 304 is connected, and the engine 304 is started using the motor generator 303 as an engine starter motor. However, the mode transition from the EV mode to the HEV mode has a mode transition scene from the EV mode to the HEV mode even when the transmission 305 (automatic transmission) is shifting. Therefore, if the clutch capacity (partial to complete ON) is not taken into account, a shock occurs when the clutch is engaged. That is, in the case of a downshift, the shift proceeds by increasing the transmission input rotation speed, but when the transmission input torque for the clutch capacity temporarily decreases by connecting the engine 304, the clutch 306 is completely engaged. When this occurs, a shock due to a sudden torque increase with a drop difference occurs, and the progress of the shift is delayed, giving a feeling of extension between the shifts.

On the other hand, in the first embodiment, during traveling in the EV mode, the engaged state of the clutch 306 and the gear ratio state of the transmission 305 are considered (step S23 and step S24), and the clutch 306 (partial to complete ON) is used. An estimated value of the input rotational speed from the engine 304 to the transmission 305 is set as the target transmission input rotational speed NT ^* (step S25). As shown in FIG. 9, the difference value ΔNT between the actual transmission input rotational speed NT and the target transmission input rotational speed NT ^* is set as a control target, and the increase speed of the output torque of the motor generator 303 is compensated for this control target. Is controlled.

Thus, by comparing the target transmission input rotational speed NT ^* taking into account the engaged state of the clutch 306 and the transmission gear ratio state of the transmission 305 and the actual transmission input rotational speed NT, the change direction of the input rotational speed of the transmission 305 (clutch The change in the direction in which the input rotational speed decreases during downshifting in the fastening direction is prefetched. In addition, the torque compensation control that increases the increase speed of the output torque in the motor generator 303 with high control responsiveness suppresses the change in the input rotation speed of the transmission 305. Depressing action.

Then, as shown in FIG. 10D, when the clutch 306 gradually shifts from the released state to the connected state, as shown in FIG. 10C, the output torque that causes the motor generator 303 to take a leading role. By performing the increase control, as shown in FIG. 10B, the engine speed rises quickly, and as a result, the acceleration lag (A) in FIG. 10 decreases.
Here, in order to reduce the acceleration lag (A), it is necessary to devise a method for adjusting the secondary side rotational speed (= MG rotational speed) of the clutch 306 with the motor generator 303. However, the motor generator 303 has a leading role. It is possible to cope with this by performing the control. That is, by taking into account the clutch capacity and controlling the rotational speed of the highly responsive motor generator 303, the latch-on time can be shortened, so that the responsiveness of the vehicle system can be improved.

[Gain setting effect of compensation torque]
In the first embodiment, in step S28, the compensation torque gain G1 is set using the compensation torque gain characteristic with respect to the distance L from the front vehicle from the inter-vehicle sensor 404 and the distance L from the front vehicle shown in FIG. The compensation torque gain G1 is given as a maximum value in a region where the distance L from the preceding vehicle is L1 or more. When the distance L from the preceding vehicle is an area less than L1, a smaller value is given as the distance L from the preceding vehicle becomes smaller.
For this reason, when the interval L with the preceding vehicle is wide and vehicle acceleration is allowed, the increase speed of the output torque in the motor generator 303 is increased, and smooth driving force control is achieved. Further, when the distance L from the preceding vehicle is narrow, the acceleration limitation can be strengthened according to the fact that the vehicle acceleration is not allowed as the distance is narrower.

In the first embodiment, in step S29, the compensation torque gain G2 is set using the topographic information from the navigation system 405 and the compensation torque gain characteristic with respect to the gradient degree θ shown in FIG. The compensation torque gain G2 is given as a reference value on a flat road with a grade of 0 as a reference value, and is given a larger value when the grade of inclination θ indicates a steep uphill on an uphill road, and the gradient degree θ on a downhill road has a steep value. It is given as a smaller value to indicate a slope downhill.
For this reason, on the uphill road where the running resistance increases and acceleration limitation is imposed, the increase speed of the output torque in the motor generator 303 is increased in accordance with the increase in running resistance, and smooth driving force control is achieved. On the downhill road where the running resistance is reduced and acceleration assist is provided, the increase speed of the output torque in the motor generator 303 is lowered in accordance with the reduction of the running resistance, and smooth driving force control is achieved. That is, stable driving force control can be achieved regardless of the gradient degree θ of the travel path.

In the first embodiment, in step S30, the compensation torque gain G3 is set using the selected mode information from the mode selection switch 406 and the compensation torque gain characteristic for the user selection mode shown in FIG. The compensation torque gain G3 is set to a reference value when “normal mode” is selected, and is set to a larger value when “sport mode” is selected than when “normal mode” is selected, and “normal mode” when “eco mode” is selected. The value is smaller than that at the time of selection.
For this reason, when the “sports mode” in which the driver intends to accelerate is selected, the increase speed of the output torque in the motor generator 303 is increased, and the driving force control corresponding to the driver's intention to accelerate is achieved. In addition, when the “eco mode” in which the driver's intention to accelerate is small and the fuel efficiency is important is selected, the increase speed of the output torque in the motor generator 303 is kept low, and the driving force control that meets the driver's fuel efficiency requirements is achieved.

Next, the effect will be described.
In the control apparatus for the FF hybrid vehicle according to the first embodiment, the effects listed below can be obtained.

(1) A driving force that includes a drive system in which a clutch 306 is interposed between an engine 304 and a motor (motor generator 303) and a transmission 305 is installed between the motor and driving wheels, and controls the output torque of the motor. In the control device for the FF hybrid vehicle provided with the control means, transmission input speed detection means (motor speed sensor 407) for detecting the actual transmission input speed NT of the transmission 305 is provided, and the driving force control means (FIG. 2). ) Is the target transmission input rotational speed NT ^* , where the input rotational speed of the transmission 305 for prefetching the change in the input rotational speed is considered in consideration of the engaged state of the clutch 306 and the gear ratio state of the transmission 305 during traveling. The actual transmission input speed NT and the target transmission input speed NT ^* The output torque of the motor is controlled so as to compensate for the control target. For this reason, by taking into account the change in clutch capacity and controlling a highly responsive motor in the drive system, it is possible to perform smooth drive force control that suppresses the occurrence of shock due to clutch engagement / disengagement.

(2) The engine speed detecting means (engine speed sensor 409) for detecting the engine speed Ne of the engine 304 is provided, and the driving force control means (FIG. 2) is configured such that the clutch 306 is in the fully engaged side. The clutch gain setting unit (step S23) for setting the clutch gain α to a larger value as the value increases, and the transmission ratio gradient setting unit for setting the transmission ratio gradient di / dt, which is the change gradient of the transmission ratio i that the transmission 305 can take. (Step S24), a target transmission input rotational speed calculation unit (step S25) that calculates a target transmission input rotational speed NT ^* by multiplying the engine rotational speed Ne, the clutch gain α, and the gear ratio gradient di / dt; Have For this reason, the target transmission input rotational speed NT ^* for prefetching the change in the input rotational speed can be accurately calculated in consideration of the engaged state of the clutch 306 and the transmission gear ratio state of the transmission 305.

(3) The driving force control means (FIG. 2) includes a difference value calculation unit (step S26) that calculates a difference value ΔNT obtained by subtracting the target transmission input rotation speed NT ^* from the actual transmission input rotation speed NT. When the value ΔNT is not zero (YES in step S27), a motor compensation torque output unit that controls the increase / decrease speed of the output torque of the motor (motor generator 303) so as to compensate for the read-ahead change of the input rotational speed that appears in the difference value ΔNT. (Step S32). For this reason, it is possible to control the motor output torque so as to compensate for the difference value ΔNT with a high degree of freedom simply by changing the gain without calculating the increase / decrease amount of the corrected output torque.

  (4) A compensation torque gain setting unit (steps S28 to S30) for setting the compensation torque gains G1, G2, and G3 for obtaining the optimum motor torque increase / decrease speed according to the traveling condition in which the allowable degree of acceleration of the vehicle changes is provided. The motor compensation torque output unit (step S32) controls the increase / decrease speed of the output torque of the motor (motor generator 303) using the compensation torque gains G1, G2, G3. For this reason, the driving force control corresponding to the change in the clutch capacity is added with a traveling condition in which the allowable degree of vehicle acceleration changes, and an optimal motor torque increase / decrease speed can be obtained according to the allowable degree of vehicle acceleration.

  (5) An inter-vehicle distance detection means (inter-vehicle sensor 404) for detecting an inter-vehicle distance between the host vehicle and an obstacle existing in front of the host vehicle is provided, and the compensation torque gain setting unit (step S28) sets an inter-vehicle distance detection value. The compensation torque gain G1 is set so that the limit is strengthened as the detected value of the inter-vehicle distance is smaller in the region below the value. For this reason, when the inter-vehicle distance is wide and vehicle acceleration is allowed, smooth driving force control can be achieved, and when the inter-vehicle distance is narrow, the acceleration limitation is strengthened as the narrow inter-vehicle distance can be maintained.

  (6) A terrain information acquisition means (navigation system 405) for acquiring terrain information of the travel route on which the vehicle travels is provided, and the supplementary torque gain setting unit (step S29) performs vehicle acceleration indicated by the acquired terrain information. In consideration of the tolerance, the compensation torque gain G2 is set to an optimum value according to the tolerance of the vehicle acceleration. Therefore, for example, stable driving force control can be achieved by adjusting the gain according to the allowable degree of vehicle acceleration regardless of the gradient degree θ of the traveling path, the turning radius of the traveling path, and the like.

  (7) A mode selection unit (mode selection switch 406) that allows the user to arbitrarily select an operation mode is provided, and the compensation torque gain setting unit (step S30) accelerates the vehicle indicated by the operation mode selected by the mode selection unit. The compensation torque gain G3 is set to an optimum value according to the vehicle acceleration tolerance. For this reason, the driving force control according to the driver's intention can be achieved by the gain adjustment reflecting the driver's mode selection intention.

  As mentioned above, although the control apparatus of the hybrid vehicle of this invention was demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, The invention which concerns on each claim of a claim Design changes and additions are permitted without departing from the gist of the present invention.

  In the first embodiment, the mode transition from the EV mode to the HEV mode, the clutch 306 is changed from the released state to the engaged state, and the engine 304 is started is shown. However, the present invention can also be adopted when the mode is changed from the HEV mode to the EV mode, the clutch 306 is changed from the engaged state to the released state, and the engine 304 is stopped.

  In the first embodiment, an example in which a downshift is performed in the transmission 305 simultaneously with the connection and disconnection of the clutch 306 is shown. However, when the clutch 306 is connected or disconnected, the transmission 305 can also employ the present invention when the AT gear stage remains fixed. The present invention can also be adopted when the transmission 305 is upshifted simultaneously with the connection / disconnection of the clutch 306.

  In the first embodiment, as an output control of the MG compensation torque, an example in which an increase speed and a decrease speed are controlled by setting a gain has been shown. However, for example, the compensation torque may be obtained according to the difference value, and the compensation torque may be added to the normal MG torque.

  In the first embodiment, the application example to the FF hybrid vehicle is shown, but the present invention can also be applied to the FR hybrid vehicle. In short, the present invention can be applied to any control device for a hybrid vehicle having a drive system in which a clutch is interposed between the engine and the motor and a transmission is installed between the motor and the drive wheels.

1 is an overall system diagram illustrating an FF hybrid vehicle (an example of a hybrid vehicle) to which a control device according to a first embodiment is applied. 3 is a flowchart illustrating a flow of a driving force control process performed by a motor generator 303 executed by a CPU 101 according to the first embodiment. FIG. 6 is a characteristic diagram illustrating a relationship of clutch gain with respect to a clutch interval of a clutch 306 used in the driving force control process of the first embodiment. FIG. 6 is a characteristic diagram illustrating a relationship of a gear ratio with respect to an example of an AT gear stage that sets a gear ratio of the transmission 305 used in the driving force control process according to the first embodiment. 6 is a diagram illustrating an example of a shift line map in the transmission 305 of Embodiment 1. FIG. It is a characteristic view which shows the relationship of the compensation torque gain with respect to the space | interval with the front vehicle used for the driving force control process of Example 1. FIG. It is a characteristic view which shows the relationship of the compensation torque gain with respect to the grade used for the driving force control process of Example 1. FIG. 6 is a characteristic diagram illustrating a relationship of a compensation torque gain with respect to “eco mode”, “normal mode”, and “sport mode” selected by a user and used in the driving force control process of the first embodiment. 4 is a time chart showing changes in the actual transmission input rotational speed and the target transmission input rotational speed in a traveling scene in which the engine start and the downshift proceed simultaneously by the accelerator depressing operation during EV traveling in the control device for the FF hybrid vehicle of the first embodiment. is there. In the control apparatus for the FF hybrid vehicle of the first embodiment, the engine speed / motor generator in the travel scene in which the transition to the EV mode is performed by performing the accelerator return operation after the transition to the HEV mode by temporarily depressing the accelerator during the EV travel. It is a time chart which shows each characteristic of rotation speed, transmission input rotation speed, AT shift stage, required torque, and clutch connection state.

Explanation of symbols

101 CPU
102 Auxiliary battery
201 Brake actuator
202 Mechanical brake
301 Heavy battery
302 inverter
303 Motor generator (motor)
304 engine
305 transmission
306 clutch
401 accelerator sensor (accelerator opening detection means)
402 Brake sensor
403 DC / DC converter
404 Inter-vehicle sensor (inter-vehicle distance detection means)
405 Navigation system (terrain information acquisition means)
406 Mode selection switch (mode selection means)
407 Motor rotation speed sensor (transmission input rotation speed detection means)
408 Vehicle speed sensor
409 Engine speed sensor (Engine speed detection means)
410 Clutch stroke sensor

Claims (6)

An electric vehicle running mode in which a clutch is interposed between the engine and the motor, and a transmission is installed between the motor and the drive wheel, the clutch is disengaged, and a hybrid vehicle running mode in which the clutch is engaged; And a hybrid vehicle control device provided with driving force control means for controlling the output torque of the motor,
A transmission input rotational speed detection means for detecting an actual transmission input rotational speed of the transmission is provided;
When the driving force demand increases during traveling in the electric vehicle traveling mode, the driving force control means engages the clutch in a half-clutch state, connects the stopped engine, and uses the motor as an engine starter motor. When the engine is started and the hybrid vehicle travel mode is entered, the transmission from the engine to the transmission via the clutch is based on the engine speed, the clutch engagement state, and the transmission gear ratio state . A difference value calculation unit that calculates a target transmission input rotation number that is an estimated value of the input rotation number and calculates a difference value obtained by subtracting the target transmission input rotation number from the actual transmission input rotation number by the motor that performs rotation number control If, while the difference value is determined to exceed zero, times By multiplying a gain to increase the normal rate of increase of the output torque to the motor torque when performing several control sets the motor compensation torque, and the motor filling torque output unit for outputting a command to obtain a motor compensation torque set to the motor A control apparatus for a hybrid vehicle characterized by comprising: In the hybrid vehicle control device according to claim 1,
Providing an engine speed detecting means for detecting the engine speed of the engine;
The driving force control means is a clutch gain setting unit which is 1 when the clutch is engaged, and is proportionally decreased from 1 to 0 when the clutch is in a half-clutch region, and is given by a value 0 when the clutch is in an open region. The gear ratio gradient, which is the gear ratio change gradient that the transmission can take, is given by gear ratio gradient = 1 when there is no change in gear ratio, given by gear ratio gradient> 1 during downshift, and gear ratio gradient during upshift. A transmission ratio gradient setting section given by <1; and a target transmission input rotation speed calculation section that calculates a target transmission input rotation speed by multiplying the engine rotation speed, the clutch gain, and the transmission ratio gradient. A control device for a hybrid vehicle. In the hybrid vehicle control device according to claim 1 or 2,
A compensation torque gain setting unit for setting a compensation torque gain to obtain an optimum motor torque increase / decrease speed according to a traveling condition in which the allowable degree of acceleration of the vehicle changes,
The motor compensation torque output unit controls the speed of increase / decrease of the output torque of the motor using the compensation torque gain. In the hybrid vehicle control device according to claim 3,
An inter-vehicle distance detecting means for detecting the inter-vehicle distance between the own vehicle and an obstacle existing in front of the own vehicle is provided.
The supplemental torque gain setting unit sets the supplemental torque gain with a more restrictive limit as the inter-vehicle distance detection value is a region where the inter-vehicle distance detection value is less than or equal to the set value. apparatus. In the hybrid vehicle control device according to claim 3 or 4,
Providing terrain information acquisition means for acquiring terrain information of the travel path on which the vehicle is traveling,
The compensation torque gain setting unit sets a compensation torque gain to an optimum value according to the allowable degree of vehicle acceleration in consideration of the allowable degree of vehicle acceleration indicated by the acquired terrain information. apparatus. In the control apparatus of the hybrid vehicle described in any one of Claims 3 thru | or 5,
Provide mode selection means that allows the user to arbitrarily select the operation mode,
The compensation torque gain setting unit sets the compensation torque gain to an optimum value according to the allowable degree of vehicle acceleration in consideration of the allowable degree of vehicle acceleration indicated by the operation mode selected by the mode selection unit. A control device for a hybrid vehicle.

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