JP4277823B2 - Electric vehicle and control method thereof - Google Patents

Description

  The present invention relates to an electric vehicle and a control method thereof, and more particularly to an electric vehicle including an electric motor capable of outputting driving power and a control method thereof.

Conventionally, this type of electric vehicle has been proposed in which an electric motor is attached to the axle side via a transmission that shifts in two stages by connecting or releasing a hydraulically driven clutch (for example, Patent Documents). 1). In this electric vehicle, when the transmission is downshifted while torque is being output from the electric motor, the hydraulic pressure of the clutch that is disconnected along with the downshift is adjusted so that the rotational speed of the electric motor is smoothly changed. The feedback control is performed based on the rotational speed of the motor and the torque output from the electric motor is corrected.
JP 2004-204960 A

  In this way, in an electric vehicle that adjusts the engagement force of the clutch that releases the connection in accordance with the downshift so that the rotation speed of the electric motor is smoothly changed, when the torque required for the electric motor rapidly increases during the downshift, Since the response of the adjustment of the hydraulic pressure of the clutch for releasing the connection with respect to the fluctuation of the rotation speed of the electric motor is low, the command in the feedback control may not be properly performed. In this case, a shift shock occurs.

  An object of the electric vehicle and the control method thereof of the present invention is to suppress a shift shock that may occur when the driving force of the electric motor is rapidly increased during a downshift.

  The electric vehicle and the control method thereof according to the present invention employ the following means in order to achieve the above-described object.

The electric vehicle of the present invention is
An electric vehicle including an electric motor capable of outputting driving power,
A plurality of clutches from the motor with a change in gear position by connecting at least one of the plurality of clutches and releasing at least one clutch different from the clutch. Shift transmission means for shifting power to transmit to the axle side;
A required driving force setting means for setting a required driving force required for traveling;
Electric motor driving force setting means for setting an electric motor driving force to be output from the electric motor based on the set required driving force and the state of the shift transmission means;
Drive control means for driving and controlling the electric motor so that the set electric motor driving force is output;
When the shift transmission means is downshifted, the clutch that is disengaged in association with the downshift during a normal shift in which the required drive force set by the required drive force setting means is within a predetermined range during the downshift. By adjusting the engagement force, the rotational speed of the electric motor is smoothly changed, and the shift transmission means is controlled so that the engagement force of the clutch connected with the downshift becomes a predetermined change, and the requested drive is performed during the downshift. At the time of non-normal shift where the required driving force set by the force setting means greatly changes beyond the predetermined range, the engaging force of the clutch for releasing the connection is released and the engaging force of the connecting clutch is changed to the predetermined change. Shift control means for controlling the shift transmission means,
It is a summary to provide.

  In the electric vehicle according to the present invention, when the shift transmission means for shifting the power from the electric motor and transmitting it to the axle side is downshifted, the required driving force required for traveling during the downshift is within a predetermined range. Shift transmission means for smoothly changing the number of revolutions of the motor by adjusting the engagement force of the clutch that is disengaged along with the downshift at the time of the normal shift, and the predetermined change of the engagement force of the clutch being connected with the downshift To control. As a result, it is possible to suppress a shift shock that may occur when the shift transmission means shifts. In addition, when downshifting the transmission means, the clutch engaging force is released and the clutch is released at the time of non-normal shift in which the required driving force greatly changes beyond a predetermined range during the downshift. The shift transmission means is controlled so that the engaging force of the gear changes to a predetermined value. In other words, in order to smoothly change the rotation speed of the electric motor, the adjustment of the engagement force of the clutch for releasing the connection is stopped, and the engagement force of the clutch for releasing the connection is released. As a result, it is possible to suppress a shift shock that may be caused by adjusting the engagement force of the clutch for releasing the connection in order to smoothly change the rotation speed of the electric motor.

  In such an electric vehicle according to the present invention, the shift transmission means is means for driving the plurality of clutches using hydraulic pressure, and the shift control means is configured to change the rotation speed of the motor smoothly during the normal shift. It is also possible to adjust the hydraulic pressure of the clutch that releases the connection based on the number of revolutions of the electric motor, and to suddenly reduce the hydraulic pressure to the clutch that releases the connection during the non-normal shift. If it carries out like this, transmission control of a transmission transmission means can be performed using oil_pressure | hydraulic. In this case, the shift control means adjusts so that the hydraulic pressure to the clutch to be connected is maintained at a substantially predetermined pressure until the rotational speed of the electric motor reaches the rotational speed after the downshift, and the rotational speed of the electric motor is After reaching the number of revolutions after downshifting, the hydraulic pressure to the clutch to be connected may be adjusted so as to gradually increase until reaching the hydraulic pressure at the time of normal connection. In this way, even if the motor speed increases rapidly due to a sudden increase in the required driving force after the motor speed reaches the speed after the downshift, the rapid increase is allowed. Torque shock that can occur with a sudden increase in the number of revolutions of the motor can be suppressed as compared with the control that does not allow the sudden increase during the rapid increase.

  Further, the electric vehicle of the present invention may include an internal combustion engine capable of outputting traveling power. In this case, the power power input / output means connected to the output shaft and the axle of the internal combustion engine and capable of outputting at least part of the power from the internal combustion engine to the axle side with input and output of power and power, Target power setting means for setting target power to be output from the internal combustion engine based on the set required driving force, and the motor driving force setting means sets the motor driving force based on the set target power. The drive control means may be means for controlling the internal combustion engine and the power power input / output means so that the set target power is output. Furthermore, in this case, the power power input / output means is connected to three shafts of the output shaft of the internal combustion engine, the axle shaft and the rotating shaft, and is based on power input / output to any two of the three shafts. It may be a means provided with a three-axis power input / output means for inputting / outputting power to the remaining shaft and a generator for inputting / outputting power to / from the rotating shaft.

  Furthermore, the electric vehicle according to the present invention may include a fuel cell that generates electric power upon receiving fuel supply, and may include a fuel cell device that can supply electric power generated by the fuel cell to the electric motor.

The electric vehicle control method of the present invention includes:
Speed change by having an electric motor capable of outputting driving power, and having a plurality of clutches and connecting at least one of the plurality of clutches and releasing at least one clutch different from the clutches Shift control means for shifting the power from the electric motor with a stage change and transmitting it to the axle side, and a control method for an electric vehicle comprising:
Set the required driving force required for driving,
Based on the set required driving force and the state of the shift transmission means, the motor driving force to be output from the motor is set,
Driving and controlling the electric motor so that the set electric motor driving force is output;
When the shift transmission means is downshifted, if the set required driving force is within a predetermined range during the downshift, the rotation speed of the electric motor is adjusted by adjusting the engagement force of the clutch that is disconnected with the downshift. The shift transmission means is controlled so that the engaging force of the clutch to be connected changes smoothly along with the downshift, and the set required driving force increases greatly beyond the predetermined range during the downshift. The shift transmission means is controlled so that the engaging force of the clutch for releasing the connection is released and the engaging force of the connecting clutch becomes the predetermined change when changed.
This is the gist.

  In the electric vehicle control method according to the present invention, when downshifting the shift transmission means for shifting the power from the electric motor and transmitting it to the axle, the required driving force required for traveling during the downshift is predetermined. During normal shifting within the range, the engagement force of the clutch that releases the connection with the downshift is adjusted to smoothly change the rotation speed of the motor, and the engagement force of the clutch that is connected with the downshift is changed to a predetermined change. Controls transmission transmission means. As a result, it is possible to suppress a shift shock that may occur when the shift transmission means shifts. In addition, when downshifting the transmission means, the clutch engaging force is released and the clutch is released at the time of non-normal shift in which the required driving force greatly changes beyond a predetermined range during the downshift. The shift transmission means is controlled so that the engaging force of the gear changes to a predetermined value. In other words, in order to smoothly change the rotation speed of the electric motor, the adjustment of the engagement force of the clutch for releasing the connection is stopped, and the engagement force of the clutch for releasing the connection is released. As a result, it is possible to suppress a shift shock that may be caused by adjusting the engagement force of the clutch for releasing the connection in order to smoothly change the rotation speed of the electric motor.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a three-shaft power distribution and integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and power distribution and integration. A motor MG1 capable of generating electricity connected to the mechanism 30, a motor MG2 connected to the power distribution and integration mechanism 30 via a transmission 60, and a hybrid electronic control unit 70 for controlling the entire drive system of the vehicle.

  The engine 22 is an internal combustion engine that outputs power using a hydrocarbon-based fuel such as gasoline or light oil, and an engine electronic control unit (hereinafter referred to as an engine ECU) that receives signals from various sensors that detect the operating state of the engine 22. ) 24 is subjected to operation control such as fuel injection control, ignition control, intake air amount adjustment control and the like. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70.

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotational elements. In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the motor MG2 is connected to the ring gear 32 via the transmission 60. The motor MG1 generates power. When the motor MG1 functions as a motor, the power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine 22 input from the carrier 34. And the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32. The ring gear 32 is mechanically connected to the drive wheels 39a and 39b via a gear mechanism 37 and a differential gear 38. Therefore, the power output to the ring gear 32 is output to the drive wheels 39a and 39b via the gear mechanism 37 and the differential gear 38.

  Both the motor MG1 and the motor MG2 are configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive and negative bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG 1 and MG 2 is supplied to another motor. It can be consumed at. Therefore, battery 50 is charged / discharged by electric power generated from motors MG1 and MG2 or insufficient electric power. Note that the battery 50 is not charged / discharged if the electric power balance is balanced by the motor MG1 and the motor MG2. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 calculates the rotational speeds Nm1 and Nm2 of the rotors of the motors MG1 and MG2 by a rotational speed calculation routine (not shown) based on signals input from the rotational position detection sensors 43 and 44. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70.

  The transmission 60 connects and disconnects the rotating shaft 48 of the motor MG2 and the ring gear shaft 32a and reduces the rotational speed of the rotating shaft 48 of the motor MG2 to two stages by connecting the both shafts to the ring gear shaft 32a. It is configured to be able to communicate. An example of the configuration of the transmission 60 is shown in FIG. The transmission 60 shown in FIG. 2 includes a double-pinion planetary gear mechanism 60a, a single-pinion planetary gear mechanism 60b, and two brakes B1 and B2. The planetary gear mechanism 60a of a double pinion includes an external gear sun gear 61, an internal gear ring gear 62 arranged concentrically with the sun gear 61, a plurality of first pinion gears 63a meshing with the sun gear 61, and the first pinion gear 63a. A plurality of second pinion gears 63b that mesh with the one pinion gear 63a and mesh with the ring gear 62, and a carrier 64 that holds the plurality of first pinion gears 63a and the plurality of second pinion gears 63b so as to rotate and revolve freely. The sun gear 61 can be freely rotated or stopped by turning on and off the brake B1. The single-pinion planetary gear mechanism 60 b includes an external gear sun gear 65, an internal gear ring gear 66 disposed concentrically with the sun gear 65, and a plurality of pinion gears 67 that mesh with the sun gear 65 and mesh with the ring gear 66. And a carrier 68 that holds a plurality of pinion gears 67 so as to rotate and revolve. The sun gear 65 is connected to the rotating shaft 48 of the motor MG2, the carrier 68 is connected to the ring gear shaft 32a, and the ring gear 66 is braked. The rotation can be freely or stopped by turning on and off B2. The double pinion planetary gear mechanism 60a and the single pinion planetary gear mechanism 60b are connected by a ring gear 62 and a ring gear 66, and a carrier 64 and a carrier 68, respectively. The transmission 60 can disconnect the rotating shaft 48 of the motor MG2 from the ring gear shaft 32a by turning off both the brakes B1 and B2, and can turn off the brake B1 and turn on the brake B2 to turn on the rotating shaft 48 of the motor MG2. Is rotated at a relatively large reduction ratio and transmitted to the ring gear shaft 32a (hereinafter, this state is referred to as a Lo gear state), the brake B1 is turned on and the brake B2 is turned off to rotate the rotating shaft 48 of the motor MG2. Is rotated at a relatively small reduction ratio and transmitted to the ring gear shaft 32a (hereinafter, this state is referred to as a Hi gear state). Note that when the brakes B1 and B2 are both turned on, the rotation of the rotary shaft 48 and the ring gear shaft 32a is prohibited.

  The brakes B1 and B2 are turned on and off by the hydraulic pressure from the hydraulic circuit 100 illustrated in FIG. The hydraulic circuit 100 is pumped from the mechanical pump 102 driven by the rotation of the engine 22, the electric pump 104 driven by the built-in electric motor 104a, and the mechanical pump 102 or the electric pump 104 as shown in the figure. A three-way solenoid 106 and a pressure control valve 108 for adjusting the oil line oil pressure PL, linear solenoids SLB1 and SLB2 for adjusting the engagement force of the brakes B1 and B2 using the line oil pressure PL, control valves 110 and 111, an accumulator 112, 113. In this hydraulic circuit 100, the line hydraulic pressure PL can be adjusted by driving the three-way solenoid 106 to control the opening / closing of the pressure control valve 108, and the engagement force of the brakes B1, B2 is linear solenoids SLB1, SLB2. It can be adjusted by controlling the opening and closing of the control valves 110 and 111 for controlling the current applied to the control valve and transmitting the line oil pressure PL to the brakes B1 and B2. In the transmission 60 of the embodiment, “brake” is used synonymously with “clutch”.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between the terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature from the temperature sensor (not shown) attached to the battery 50, and the like are input. Output to the control unit 70. The battery ECU 52 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 50.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72. In addition to the CPU 72, a ROM 74 that stores processing programs, a RAM 76 that temporarily stores data, an input / output port and communication (not shown), and the like. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. From the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the temperature sensor 114 that detects the temperature of oil in the hydraulic circuit 100. The oil temperature Toil etc. is input via the input port. The hybrid electronic control unit 70 outputs a drive signal to the electric motor 104a, a drive signal to the three-way solenoid 106, a drive signal to the linear solenoids SLB1, SLB2, and the like via an output port. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via communication ports, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. Is doing.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, the operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is the power distribution and integration mechanism 30. Torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that suitable power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is the power distribution and integration mechanism 30, the motor MG1, and the motor. The required power is converted to the ring gear shaft 32 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled to be output to each other, and a motor operation mode in which the operation of the engine 22 is stopped and the power corresponding to the required power from the motor MG2 is output to the ring gear shaft 32a. and so on.

  Next, the operation of the hybrid vehicle 20 of the embodiment, particularly the operation when the transmission 60 is downshifted from the Hi gear state to the Lo gear state will be described. FIG. 4 is a shift drive control routine executed by the hybrid electronic control unit 70 of the embodiment as drive control of the engine 22 and the motors MG1, MG2 at the time of downshift, and FIG. FIG. 6 is a connection side control routine executed by the hybrid electronic control unit 70 of the embodiment as a control of the brake B2 of the machine 60, and FIG. 6 is executed as a control of the brake B1 of the transmission 60 that is released in connection with the downshift. It is the cancellation | release side control routine performed by the hybrid electronic control unit 70 of an example. 4 is repeatedly executed every predetermined time (for example, every several msec) after the downshift of the transmission 60 is started. The connection side control routine of FIG. 5 and the release side control of FIG. The routine is executed concurrently with the transmission axis control routine when a downshift of the transmission 60 is started. Hereinafter, first, drive control will be described, and then connection side control and release side control will be described.

  4 is executed, first, the CPU 72 of the hybrid electronic control unit 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the motors MG1, MG2. A process of inputting data necessary for control, such as the rotation speed Nm1, Nm2, charge / discharge required power Pb *, input / output limits Win, Wout of the battery 50, is executed (step S100). Here, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. To do. The charge / discharge required power Pb * is input from the battery ECU 52 by communication from the battery ECU 52 as power to be charged / discharged by the battery ECU 52 based on the remaining capacity (SOC) of the battery 50 or the like. Further, the input / output limits Win and Wout of the battery 50 are set based on the battery temperature Tb of the battery 50 and the remaining capacity (SOC) of the battery 50 and input from the battery ECU 52 by communication.

  When the data is input in this way, the gear ratio Gr of the transmission 60 is calculated by dividing the input rotational speed Nm2 of the motor MG2 by the rotational speed Nr (kv · V) of the ring gear shaft 32a (step S110). The required torque Tr * to be output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 39a and 39b as the torque required for the vehicle based on the degree Acc and the vehicle speed V and the required power Pe required for the engine 22 * Is set (step S120). In the embodiment, the required torque Tr * is determined in advance by storing the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Tr * in the ROM 74 as a required torque setting map, and the accelerator opening Acc, the vehicle speed V, , The corresponding required torque Tr * is derived and set from the stored map. FIG. 7 shows an example of the required torque setting map. The required power Pe * can be calculated as the sum of the set required torque Tr * multiplied by the rotation speed Nr of the ring gear shaft 32a, the battery required power Pb *, and the loss Loss. The rotational speed Nr of the ring gear shaft 32a can be obtained by multiplying the vehicle speed V by the conversion factor kv, or can be obtained by dividing the rotational speed Nm2 of the motor MG2 by the gear ratio Gr of the transmission 60.

  Based on the set required power Pe *, the target rotational speed Ne * and the target torque Te * of the engine 22 are set (step S130). In this setting, the target rotational speed Ne * and the target torque Te * are set based on the operation line for efficiently operating the engine 22 and the required power Pe *. FIG. 8 shows an example of the operation line of the engine 22 and how the target rotational speed Ne * and the target torque Te * are set. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained from the intersection of the operation line and a curve with a constant required power Pe * (Ne * × Te *).

  Next, using the set target rotational speed Ne *, the rotational speed Nr (kv · V) of the ring gear shaft 32a, and the gear ratio ρ of the power distribution and integration mechanism 30, the target rotational speed Nm1 of the motor MG1 is given by the following equation (1). * And a torque command Tm1 * of the motor MG1 is calculated by the equation (2) based on the calculated target rotational speed Nm1 * and the current rotational speed Nm1 (step S140). Here, Expression (1) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 9 is a collinear diagram showing a dynamic relationship between the number of rotations and torque in the rotating elements of the power distribution and integration mechanism 30. In the figure, the left S-axis indicates the rotation speed of the sun gear 31 that is the rotation speed Nm1 of the motor MG1, the C-axis indicates the rotation speed of the carrier 34 that is the rotation speed Ne of the engine 22, and the R-axis indicates the rotation speed of the motor MG2. The rotational speed Nr of the ring gear 32 obtained by multiplying the number Nm2 by the gear ratio Gr of the transmission 60 is shown. Expression (1) can be easily derived by using this alignment chart. The two thick arrows on the R axis indicate that torque Te * output from the engine 22 when the engine 22 is normally operated at the operation point of the target rotational speed Ne * and the target torque Te * is transmitted to the ring gear shaft 32a. Torque and torque that the torque Tm2 * output from the motor MG2 acts on the ring gear shaft 32a via the transmission 60. Expression (2) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (2), “k1” in the second term on the right side is a gain of a proportional term. “K2” in the third term on the right side is the gain of the integral term.

Nm1 * ＝ Ne * ・ (1 + ρ) / ρ−kv ・ V / ρ (1)
Tm1 * = previous Tm1 * + k1 (Nm1 * −Nm1) + k2∫ (Nm1 * −Nm1) dt (2)

  Subsequently, the deviation between the power limit (generated power) of the motor MG1 obtained by multiplying the output limit Wout of the battery 50 and the calculated torque command Tm1 * of the motor MG1 by the current rotational speed Nm1 of the motor MG1 is the rotation of the motor MG2. Torque limits Tmin and Tmax as upper and lower limits of the torque that may be output from the motor MG2 by dividing by several Nm2 are calculated by the following equations (3) and (4) (step S150), and the required torque Tr * Using the torque command Tm1 * and the gear ratio ρ of the power distribution and integration mechanism 30, a temporary motor torque Tm2tmp as a torque to be output from the motor MG2 is calculated by the equation (5) (step S160), and the calculated torque limits Tmin and Tmax are calculated. Is limited to the temporary motor torque Tm2tmp in the torque command Tm2 * of the motor MG2. (Step S170). By setting the torque command Tm2 * of the motor MG2 in this way, the required torque Tr * output to the ring gear shaft 32a as the drive shaft is limited to the input / output limit of the battery 50 even while the transmission 60 is downshifted. It can be set as a torque limited within the range of Win and Wout. Equation (5) can be easily derived from the collinear diagram of FIG. 9 described above.

Tmin ＝ (Win−Tm1 * ・ Nm1) / Nm2 (3)
Tmax ＝ (Wout−Tm1 * ・ Nm1) / Nm2 (4)
Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (5)

  Thus, when the target engine speed Ne *, the target torque Te *, and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2 are set, the target engine speed Ne * and the target torque Te * of the engine 22 are set in the engine ECU 24. The torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S180), and the drive control routine is terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * performs fuel injection control in the engine 22 such that the engine 22 is operated at an operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as ignition control. The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * controls the switching elements of the inverters 41 and 42 so that the motor MG1 is driven by the torque command Tm1 * and the motor MG2 is driven by the torque command Tm2 *. To do.

  Next, the control of the brake B2 of the transmission 60 to be connected with the downshift will be described using the connection side control routine of FIG. In the connection side control routine, the CPU 72 of the hybrid electronic control unit 70 first executes fast fill in order to fill the cylinder of the brake B2 with working oil (step S200), and then gradually increases the engagement force of the brake B2. It waits at a low pressure so that it can be increased (step S210). Fast fill or low pressure standby can be performed by changing the adjustment pressure of the control valve 111 by changing the duty ratio DB2 of the current applied to the linear solenoid SLB2.

  Subsequently, the duty ratio DB2 is set so that the duty ratio DB2 gradually increases as time elapses after waiting for low pressure (step S220), and the rotational speed Nm2 of the motor MG2 and the vehicle speed V are input. (Step S230), the vehicle speed V is multiplied by the conversion factor kv to calculate the rotational speed Nr of the ring gear shaft 32a (Step S240), and the calculated rotational speed Nr of the ring gear shaft 32a and the rotational speed Nm2 of the motor MG2 are in the state of the Lo gear. A rotation speed difference ΔN from the rotation speed divided by the gear ratio Glow is calculated (step S250). Then, the calculated rotation speed difference ΔN is compared with the threshold value Nref (step S260). Here, the threshold value Nref is used to determine whether or not the rotation speed Nm2 of the motor MG2 has substantially reached the rotation speed after the downshift, that is, synchronization of the rotation speed, and is set as a relatively small value. When the rotational speed difference ΔN is greater than or equal to the threshold value Nref, it is determined that synchronization has not been performed yet, the process returns to step S220, and the processes of steps S220 to S260 are repeatedly executed.

  When the rotational speed difference ΔN becomes less than the threshold value Nref, it is determined that the rotation synchronization of the transmission 60 has been performed, and the duty ratio DB2 of the current applied to the linear solenoid SLB2 is completely set so that the engagement force of the brake B2 gradually increases. When the rate value Drt is increased so as to gradually increase until the threshold value Dhref slightly smaller than the engagement duty ratio Dhi is reached, a process of waiting for a predetermined time to elapse (steps S270 to S290) is repeated, and the duty ratio DB2 reaches the threshold value Dhref. Then, the duty ratio DB2 is set to the fully engaged duty ratio Dhi (step S295), and the connection side control routine is terminated. Thus, the engagement force of the brake B2 can be gradually increased by changing the duty ratio DB2 of the current applied to the linear solenoid SLB2 every time the duty ratio DB2 is changed and set. Here, the reason for gradually increasing the engagement force of the brake B2 after determining the rotation synchronization of the transmission 60 is that the driver further depresses the accelerator pedal 83 during the downshift of the transmission 60, so that the motor MG2 Brake B2 so that the rotational speed Nm2 of the motor MG2 gradually returns to the rotational speed after the downshift when the rotational speed Nm2 of the motor MG2 rises beyond the rotational speed after the downshift. By gradually increasing the engagement force of the brake B2, the torque shock caused by the inertia torque caused by suddenly increasing the engagement force of the brake B2 to suddenly change the rotation speed Nm2 of the motor MG2 to the rotation speed after the downshift is suppressed. It is to do. Therefore, the unexpected torque shock that may occur when the transmission 60 is downshifted can be suppressed by gradually increasing the engagement force of the brake B2 after determining the rotation synchronization of the transmission 60 in this way. It can be done.

  Next, the control of the brake B1 of the transmission 60 that releases the connection along with the downshift will be described using the release side control routine of FIG. In the release-side control routine, the CPU 72 of the hybrid electronic control unit 70 first executes a process of inputting the required torque Tr * set when the downshift of the transmission 60 is started as the start required torque Trst. (Step S300). Then, the currently set required torque Tr * and the rotation speed Nm2 of the motor MG2 are input (step S310), and the start required torque Trst is subtracted from the input required torque Tr * to calculate the torque deviation ΔT ( In step S320, the calculated torque deviation ΔT is compared with the threshold value Tref (step S330). Here, the threshold value Tref is used to determine whether or not the engagement force of the brake B1 can be feedback-controlled in order to smoothly change the rotation speed of the motor MG2 in accordance with the downshift. It can be set as the upper limit value of the change range of the required torque Tr * that can smoothly change the rotational speed of MG2.

  When the torque deviation ΔT is less than the threshold Tref, the target rotational speed Nm2 * of the motor MG2 is set based on the elapsed time t from the start of the downshift of the transmission 60 (step S340), and the motor MG2 is set to the target rotational speed Nm2 *. The duty ratio DB1 of the current of the linear solenoid SLB1 is set by the following equation (6) so that the difference between the rotational speed Nm2 input so as to rotate at the target rotational speed Nm2 * is eliminated (step S350), and the linear solenoid SLB1 It is determined whether or not the current duty ratio DB1 has become equal to or less than the threshold value Dlref set as a value slightly larger than the complete cancellation duty ratio Dlow (step S360). Here, in equation (6), “kb” is a gain. When the duty ratio DB2 is set in this way, the hybrid electronic control unit 70 sets the duty ratio DB1 of the current applied to the linear solenoid SLB1 to the set duty ratio, so that the rotational speed Nm2 of the motor MG2 becomes the target rotational speed Nm2 *. To match. When the duty ratio DB1 does not reach the threshold value Dlref or less, the process returns to step S310 and repeats steps S310 to S360. When the duty ratio DB1 reaches the threshold value Dlref or less, the duty ratio DB1 of the current of the linear solenoid SLB1 is set to the duty for complete cancellation. The ratio Dlow is set (step S370), and the release side control routine is terminated.

  DB1 = previous DB1 + kb ・ (Nm2 * -Nm2) (6)

  When the driver depresses the accelerator pedal 83 and the required torque Tr * is largely changed during execution of feedback control so that the motor MG2 rotates at the target rotational speed Nm2 *, the torque deviation calculated in step S320 ΔT is equal to or greater than the threshold value Tref. In this case, the feedback control of the rotational speed of the motor MG2 is stopped, the duty ratio DB1 of the current of the linear solenoid SLB1 is set to the complete release duty ratio Dlow (step S370), and the release side control routine is ended. Thus, the reason why the feedback control is stopped when the torque deviation ΔT becomes equal to or greater than the threshold value Tref is that the control of the hydraulic circuit 100 is less responsive than the control of the electric motor such as the motor MG2. If the feedback control is continued even when the torque deviation ΔT is equal to or greater than the threshold value Tref, it is necessary to suppress the rotation speed Nm2 of the motor MG2 from greatly exceeding the target rotation speed Nm2 *, so that the engagement force of the brake B1 is increased. The duty ratio DB1 of the solenoid SLB1 is increased to make the hydraulic pressure act on the brake B1. At this time, the hydraulic pressure remains large, the release of the engagement force of the brake B1 is delayed, and a shift shock occurs. In the embodiment, in order to suppress such a shift shock, when the torque deviation ΔT becomes equal to or greater than the threshold value Tref, the feedback control by the engagement force of the brake B1 of the rotation speed of the motor MG2 is stopped.

  FIG. 10 shows an example of a change over time in the duty ratio for obtaining the rotational speed Nm2 of the motor MG2 and the engaging force of the brakes B1 and B2 during downshifting of the transmission 60. In the figure, the broken line of the normal time hydraulic pressure command is the time change of the duty DB2 of the brake B2 on the connection side, and the solid line of the normal time hydraulic pressure command is the brake B1 on the release side when the required torque Tr * does not change significantly during the downshift. The solid line of the non-normal time hydraulic pressure command is the time change of the duty ratio DB1 of the release-side brake B1 when the required torque Tr * changes greatly during the downshift. Further, in the figure, the solid line of the motor rotational speed is the change over time of the target rotational speed Nm2 * of the motor MG2 and the rotational speed Nm2 of the motor MG2 when the required torque Tr * does not change significantly during the downshift. A broken line is a time change of the rotation speed Nm2 of the motor MG2 when the accelerator pedal 83 is depressed. During normal time when the accelerator pedal 83 is depressed during downshift and the required torque Tr * does not change significantly, the downshift of the transmission 60 is started at time T1, as indicated by the solid line of the motor speed and the normal time hydraulic pressure command. Then, the duty ratio DB1 of the release-side brake B1 is feedback controlled so as to rotate the rotational speed Nm2 of the motor MG2 at the target rotational speed Nm2 *. The duty ratio DB2 of the brake B2 on the connection side is once increased for fast fill, then decreased to wait at a low pressure, and then gradually increased. Then, at time T3 when the rotation synchronization of the transmission 60 is determined, the duty ratio DB1 of the release-side brake B1 is set to the complete release duty ratio Dlow, and the duty ratio DB2 of the connection-side brake B2 is increased so as to gradually increase. Thus, the fully engaged duty ratio Dhi is set. When the accelerator pedal 83 is depressed during the downshift and the required torque Tr * changes significantly, the rotational speed of the motor MG2 is changed at the time T2 when the required torque Tr * changes greatly as shown in the non-normal hydraulic command. The feedback control for rotating Nm2 at the target rotational speed Nm2 * is stopped, and the duty ratio DB1 of the brake B1 on the release side is set to the duty ratio Dlow for complete release. As a result, it is possible to suppress a shift shock that may be caused by continuing the feedback control. At this time, the rotational speed Nm2 of the motor MG2 blows up, but the blow-up is suppressed by the engagement force of the brake B2 on the connection side. Even if the motor MG2 blows up after the determination of the rotation synchronization of the transmission 60, the engagement force of the brake B2 on the connection side is gradually increased, so that the motor MG2 is also lifted relatively slowly. The torque shock that occurs at that time is suppressed.

  According to the hybrid vehicle 20 of the above-described embodiment, when the required torque Tr * changes greatly due to the accelerator pedal 83 being depressed when the transmission 60 is downshifted, the motor is based on the engagement force of the brake B1 on the release side. By stopping the feedback control for rotating MG2 at the target rotational speed Nm2 *, it is possible to suppress a shift shock that may occur based on the low control response of the hydraulic circuit 100. Further, after the rotation synchronization of the transmission 60 is determined, the engagement force of the brake B2 on the connection side is gradually increased. Therefore, even if the motor MG2 blows up at this time, the motor MG2 blows up relatively. The torque shock that occurs can be suppressed. Of course, when the transmission 60 is downshifted, feedback control is performed to rotate the motor MG2 by the engagement force of the brake B1 on the release side at the target rotational speed Nm2 *, thereby smoothing the downshift while suppressing the shift shock. Can be done.

  In the hybrid vehicle 20 of the embodiment, when the required torque Tr * changes greatly when the transmission 60 is downshifted, feedback control is performed to rotate the motor MG2 by the engagement force of the release-side brake B1 at the target rotational speed Nm2 *. Although it is supposed to be canceled, it is not a change in the required torque Tr *, but a feedback that rotates the motor MG2 by the engagement force of the brake B1 on the release side at the target rotational speed Nm2 * when the torque command Tm2 * of the motor MG2 changes greatly. The control may be stopped.

  In the hybrid vehicle 20 of the embodiment, the transmission 60 is configured as a two-stage stepped transmission, but may be configured as a three-stage or more stepped transmission.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is changed by the transmission 60 and output to the ring gear shaft 32a. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. May be connected to an axle (an axle connected to wheels 39c and 39d in FIG. 11) different from an axle to which the ring gear shaft 32a is connected (an axle to which the drive wheels 39a and 39b are connected).

  In the hybrid vehicle 20 of the embodiment, the power of the engine 22 is output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 39a and 39b via the power distribution and integration mechanism 30, but the modified example of FIG. The hybrid vehicle 220 includes an inner rotor 232 connected to the crankshaft 26 of the engine 22 and an outer rotor 234 connected to a drive shaft that outputs power to the drive wheels 39a and 39b. A counter-rotor motor 230 that transmits a part of the power to the drive shaft and converts the remaining power into electric power may be provided.

  In the hybrid vehicle 20 of the embodiment, the engine 22, the power distribution and integration mechanism 30, the two motors MG <b> 1 and MG <b> 2, and the transmission 60 constitute a power system, but the axle side and the electric motor are connected via the transmission. Since the above-described control in the downshift of the transmission can be performed with the connected configuration, the power system may be configured by the power generation device, the electric motor, and the transmission. For example, as illustrated in the electric vehicle 320 of the modified example of FIG. 13, a power system is configured by a fuel cell device FC in which a fuel cell is incorporated as a power generation device and a motor MG connected to the axle side via a transmission. It is good also as what to do.

  In the examples, the embodiment of the present invention has been described as a hybrid vehicle. However, the present invention is not limited to an automobile, and may be applied to a vehicle such as a train. Moreover, it is good also as a form of the control method of not only the form of a vehicle but an electric vehicle.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention can be used in the manufacturing industry of electric vehicles.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. FIG. 3 is a configuration diagram showing an outline of a configuration of a transmission 60. 1 is a configuration diagram showing an outline of the configuration of a hydraulic circuit 100. FIG. This is a shift drive control routine executed by the hybrid electronic control unit 70 of the embodiment as drive control of the engine 22 and the motors MG1, MG2 during downshift. This is a connection-side control routine that is executed by the hybrid electronic control unit 70 of the embodiment as control of the brake B2 of the transmission 60 that is connected along with the downshift. This is a release-side control routine that is executed by the hybrid electronic control unit 70 of the embodiment as control of the brake B1 of the transmission 60 that is released in connection with a downshift. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows a mode that an example of the operating line of the engine 22, and target rotational speed Ne * and target torque Te * are set. FIG. 4 is an explanatory diagram showing an example of a collinear diagram for dynamically explaining rotational elements of a power distribution and integration mechanism 30; It is explanatory drawing which shows an example of the time change of the duty ratio for obtaining the rotation speed Nm2 of motor MG2 in the middle of downshifting transmission 60, and the engaging force of brakes B1 and B2. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example. FIG. 11 is a configuration diagram illustrating an outline of a configuration of an electric vehicle 320 according to a modification.

Explanation of symbols

20, 120, 220 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier , 37 gear mechanism, 38 differential gear, 39a, 39b drive wheel, 39c, 39b wheel, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 52 battery Electronic control unit (battery ECU), 54 power line, 60 transmission, 60a planetary gear mechanism of double pinion, 60b planetary gear mechanism of single pinion, 61 sun gear, 62 ring gear, 63a first pinion gear, 63b Second pinion gear, 64 carrier, 65 sun gear, 66 ring gear, 67 pinion gear, 68 carrier, 70 electronic control unit for hybrid, 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator Pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 102 Mechanical pump, 104 Electric pump, 104a Electric motor, 106 3-way solenoid, 108 Pressure control valve, 110, 111 Control valve 112, 113 Accumulator, 114 Temperature sensor, 320 Electric vehicle, SLB1, SLB2 Linear solenoid, MG1, MG2 Motor, B 1, B2 Brake, FC Fuel cell device.

Claims (8)

An electric vehicle including an electric motor capable of outputting driving power,
A plurality of clutches from the motor with a change in gear position by connecting at least one of the plurality of clutches and releasing at least one clutch different from the clutch. Shift transmission means for shifting power to transmit to the axle side;
A required driving force setting means for setting a required driving force required for traveling;
Electric motor driving force setting means for setting an electric motor driving force to be output from the electric motor based on the set required driving force and the state of the shift transmission means;
Drive control means for driving and controlling the electric motor so that the set electric motor driving force is output;
When the shift transmission means is downshifted, the clutch that is disengaged in association with the downshift during a normal shift in which the required drive force set by the required drive force setting means is within a predetermined range during the downshift . The speed change transmission means is controlled so that the engagement force of the clutch to be connected with the downshift is changed by a predetermined change by changing the rotation speed of the electric motor by feedback control by the engagement force, and the required driving force during the downshift. At the time of a non-normal shift in which the required driving force set by the setting means greatly increases beyond the predetermined range, the engagement force of the clutch that releases the connection is released without performing the feedback control, and the engagement of the clutch that is connected Shift control means for controlling the shift transmission means so that the resultant force becomes the predetermined change;
An electric vehicle comprising: The electric vehicle according to claim 1,
The transmission transmission means is means for driving the plurality of clutches using hydraulic pressure,
The shift control means is a means for feedback-controlling the hydraulic pressure of the clutch that releases the connection based on the number of revolutions of the electric motor during the normal shift, and for rapidly decreasing the hydraulic pressure to the clutch that releases the connection during the non-normal shift. There is an electric vehicle.   The shift control means adjusts so that the hydraulic pressure to the clutch to be connected is maintained at a substantially predetermined pressure until the rotational speed of the electric motor reaches the rotational speed after the downshift, and the rotational speed of the electric motor is 3. The electric vehicle according to claim 2, wherein the electric vehicle is a means for adjusting the hydraulic pressure to the clutch to be gradually increased until reaching the hydraulic pressure at the time of normal connection after reaching the number of revolutions.   The electric vehicle according to claim 1, further comprising an internal combustion engine capable of outputting driving power. The electric vehicle according to claim 4,
Power power input / output means connected to the output shaft and axle of the internal combustion engine and capable of outputting at least part of the power from the internal combustion engine to the axle side with input and output of power and power;
Target power setting means for setting target power to be output from the internal combustion engine based on the set required driving force;
With
The electric motor driving force setting means is means for setting an electric motor driving force based on the set target power,
The drive control means is means for controlling the internal combustion engine and the power power input / output means so that the set target power is output. The power power input / output means is connected to the three shafts of the output shaft of the internal combustion engine, the axle and the rotating shaft, and is used as a remaining shaft based on power input / output to / from any two of the three shafts. The electric vehicle according to claim 5, wherein the electric vehicle includes a three-shaft power input / output unit that inputs / outputs power and a generator that inputs / outputs power to / from the rotating shaft.   The electric vehicle according to any one of claims 1 to 3, further comprising a fuel cell device that has a fuel cell that generates power upon receiving fuel supply and that can supply the electric power generated by the fuel cell to the electric motor. Speed change by having an electric motor capable of outputting driving power, and having a plurality of clutches and connecting at least one of the plurality of clutches and releasing at least one clutch different from the clutches Shift control means for shifting the power from the electric motor with a stage change and transmitting it to the axle side, and a control method for an electric vehicle comprising:
Set the required driving force required for driving,
Based on the set required driving force and the state of the shift transmission means, the motor driving force to be output from the motor is set,
Driving and controlling the electric motor so that the set electric motor driving force is output;
When the shift transmission means is downshifted, if the set required driving force is within a predetermined range during the downshift, the rotational speed of the electric motor is controlled by feedback control based on the clutch engaging force that is disengaged with the downshift. And the shift transmission means is controlled so that the engagement force of the clutch to be connected changes along with the downshift, and the set required driving force greatly increases beyond the predetermined range during the downshift. A control method for an electric vehicle that controls the shift transmission means so that the engagement force of the clutch that releases the connection is released without performing the feedback control and the engagement force of the clutch that is connected changes to the predetermined change without performing the feedback control .

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