JP4527736B2 - VEHICLE, ITS CONTROL METHOD AND DRIVE DEVICE - Google Patents

Description

  The present invention relates to a vehicle, a control method thereof, and a drive device.

Conventionally, as this type of vehicle, a vehicle that travels using power from a motor has been proposed (see, for example, Patent Document 1). In this vehicle, when it is stopped on the uphill road while maintaining the accelerator opening constant, that is, the vehicle is in a current concentration state where the current concentrates on only one specific phase of each phase coil of the motor. In some cases, the torque output from the motor is reduced at a predetermined rate, the vehicle is moved backward to temporarily leave the current concentration state, thereby suppressing the heat generation of the motor and its drive circuit.
JP-A-11-215687

  Generally, in the above-described vehicle, after executing the control for reducing the torque output from the motor and moving the vehicle backward, the torque increase control for increasing the torque output from the motor is executed to stop the vehicle. If the torque is increased slowly when such torque increase control is executed, the driver will feel a sense of inconvenience because the torque based on the drive request cannot be quickly output from the motor the next time the accelerator pedal is depressed. . Therefore, when executing the torque increase control, it is desirable to perform control in consideration of the driver's drive request.

  An object of the vehicle, the control method thereof, and the drive device of the present invention is to perform control in consideration of a driver's drive request.

  The vehicle, the control method thereof, and the drive device of the present invention employ the following means in order to achieve the above-described object.

The vehicle of the present invention
An electric motor capable of outputting power to the axle, an accelerator operation amount detection means for detecting an accelerator operation amount, a gradient reflection physical quantity detection means for detecting a gradient reflection physical quantity that is a physical quantity reflecting a road surface gradient, and the accelerator operation amount In a vehicle comprising: required driving force setting means for setting required driving force required for traveling; and control means for controlling the electric motor so that torque based on the set required driving force is output from the electric motor. ,
When the predetermined torque decrease / increase condition is satisfied in a state where the vehicle is substantially stopped, the control means is provided until the predetermined reverse occurs in the vehicle on the condition that the detected accelerator operation amount does not change. The motor is controlled so that the torque output from the motor decreases with a first change amount, and the torque output from the motor after the predetermined reverse movement is detected as the detected accelerator operation amount. It is means for controlling the electric motor so as to increase with a second change amount based on the gradient reflected physical quantity.

  In the vehicle according to the present invention, when a predetermined torque decrease / increase condition is satisfied in a state where the vehicle is substantially stopped, from the electric motor until the predetermined reverse occurs in the vehicle on condition that there is no change in the detected accelerator operation amount. The motor is controlled so that the output torque decreases with the first amount of change, and after a predetermined reverse occurs, the torque output from the motor is based on the detected accelerator operation amount and the detected gradient reflecting physical amount. The electric motor is controlled so as to increase with the second change amount. In general, the smaller the accelerator operation amount, the smaller the driver's request for driving.However, even when the accelerator operation amount is small, the driver requests driving instead of stopping when the vehicle stops on a gentle slope. It is thought that. Conversely, when the vehicle is stopped on a steep road even when the accelerator operation amount is large, it is considered that the driver is requesting a stop rather than driving the vehicle. Therefore, after a predetermined reverse occurs, the torque output from the motor is increased by the second change amount based on the accelerator operation amount and the gradient reflected physical amount, thereby performing control in consideration of the driver's drive request. Can do. Here, “predetermined retreat” includes retreat to such an extent that the phase in which the current is concentrated among the phase coils of the electric motor is switched.

  In such a vehicle of the present invention, the second change amount is set to increase as the road surface gradient based on the detected gradient reflected physical quantity decreases and as the detected accelerator operation amount increases. You can also When the accelerator operation amount is constant, it is considered that the driving demand of the driver increases as the road surface gradient decreases. In addition, when the road surface gradient is constant, it is considered that the driver's drive demand increases as the accelerator operation amount increases. Therefore, the torque output from the electric motor is rapidly increased by setting the tendency that the second change amount is increased as the road surface gradient is smaller and the accelerator operation amount is larger, that is, as the driver's driving request is larger. The torque based on the drive request can be output from the electric motor more quickly when the next drive request is made by the driver. In addition, the torque output from the electric motor can be slowly increased by setting the second change amount to be smaller as the road surface gradient is larger and the accelerator operation amount is smaller, thereby improving riding comfort. be able to.

  In the vehicle of the present invention, the first change amount may be set based on the detected accelerator operation amount, and the first change amount may be set by the set request. It can also be set based on the driving force. If it carries out like this, when reducing the torque output from an electric motor, the control which considered the driver | operator's drive request | requirement can be performed. In this case, the first change amount may be set so as to increase as the detected accelerator operation amount increases. The greater the accelerator operation amount, that is, the greater the driver's drive request, the faster the vehicle can be moved backward to suppress heat generation of the electric motor. Further, since the first change amount is set to be smaller as the accelerator operation amount is smaller, the vehicle can be slowly moved backward to improve the riding comfort. The first change amount may be set so as to increase as the torque to be output from the electric motor set based on the set required driving force increases. If it carries out like this, a vehicle will be reverse | retreated rapidly, so that the torque which should be output from an electric motor becomes large, ie, the electric current which flows into an electric motor is large, and the heat_generation | fever of an electric motor can be suppressed.

  Furthermore, in the vehicle of the present invention, the predetermined torque decrease / increase condition may be a condition in which a torque equal to or greater than a predetermined torque is output from the electric motor for a predetermined time or more.

  And the vehicle of this invention can also be equipped with the internal combustion engine which can output motive power to an axle. In this way, in a vehicle that can travel using the power from the internal combustion engine and the power from the electric motor, it is possible to perform control in consideration of the driver's drive request.

The drive device of the present invention is
An electric motor capable of outputting power to the axle, an accelerator operation amount detection means for detecting an accelerator operation amount, a gradient reflection physical quantity detection means for detecting a gradient reflection physical quantity that is a physical quantity reflecting a road surface gradient, and the accelerator operation amount A required driving force setting means for setting the required driving force required for traveling, and a control means for controlling the electric motor so that torque based on the set required driving force is output from the electric motor, In the drive device mounted on
When the predetermined torque decrease / increase condition is satisfied in a state where the vehicle is substantially stopped, the control means is configured until the predetermined reverse movement occurs in the vehicle on the condition that the detected accelerator operation amount does not change. The motor is controlled so that the torque output from the motor decreases with a first amount of change, and the torque output from the motor after the predetermined reverse movement is detected as the detected accelerator operation amount. It is means for controlling the electric motor so as to increase with a second change amount based on the gradient reflected physical quantity.

  In the drive device according to the present invention, when a predetermined torque decrease / increase condition is satisfied in a state where the vehicle is substantially stopped, the electric motor is operated until a predetermined reverse occurs in the vehicle on condition that there is no change in the detected accelerator operation amount. The motor is controlled so that the torque output from the motor decreases with the first change amount, and after a predetermined reverse, the torque output from the motor is detected as the accelerator operation amount detected and the detected gradient reflecting physical amount. The electric motor is controlled so as to increase with the second change amount based thereon. In general, the smaller the accelerator operation amount, the smaller the driver's request for driving.However, even when the accelerator operation amount is small, the driver requests driving instead of stopping when the vehicle stops on a gentle slope. It may be thought that On the contrary, even when the accelerator operation amount is large, when the vehicle is stopped on a steep road surface, it may be considered that the driver is requesting a stop instead of driving the vehicle. Therefore, after a predetermined reverse occurs, the torque output from the motor is increased by the second change amount based on the accelerator operation amount and the gradient reflected physical amount, thereby performing control in consideration of the driver's drive request. Can do. Here, “predetermined retreat” includes retreat to such an extent that the phase in which the current is concentrated among the phase coils of the electric motor is switched.

The vehicle control method of the present invention includes:
In a vehicle including an electric motor capable of outputting power to an axle, a required driving force required for traveling is set based on an accelerator operation amount, and the torque based on the set required driving force is output from the electric motor. In a vehicle control method for controlling an electric motor,
When a predetermined torque increase condition is satisfied when the vehicle is substantially stopped, the torque output from the electric motor until the predetermined reverse occurs on the vehicle on the condition that there is no change in the accelerator operation amount. The electric motor is controlled so as to decrease with a change amount of 1, and after the predetermined backward movement occurs, the torque output from the electric motor is based on the accelerator operation amount and a gradient reflecting physical quantity that is a physical quantity reflecting the road surface gradient. The electric motor is controlled so as to increase with the second change amount.

  In the vehicle control method according to the present invention, when a predetermined torque decrease / increase condition is satisfied with the vehicle substantially stopped, a predetermined reverse movement occurs in the vehicle on condition that there is no change in the detected accelerator operation amount. The motor is controlled so that the torque output from the motor decreases with the first change amount, and after a predetermined reverse movement, the accelerator operation amount in which the torque output from the motor is detected and the detected gradient reflecting physical quantity The motor is controlled so as to increase with the second change amount based on the above. In general, the smaller the accelerator operation amount, the smaller the driver's request for driving.However, even when the accelerator operation amount is small, the driver requests driving instead of stopping when the vehicle stops on a gentle slope. It may be thought that On the contrary, even when the accelerator operation amount is large, when the vehicle is stopped on a steep road surface, it may be considered that the driver is requesting a stop instead of driving the vehicle. Therefore, after a predetermined reverse occurs, the torque output from the motor is increased by the second change amount based on the accelerator operation amount and the gradient reflected physical amount, thereby performing control in consideration of the driver's drive request. Can do. Here, “predetermined retreat” includes retreat to such an extent that the phase in which the current is concentrated among the phase coils of the electric motor is switched.

  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 a configuration of an electric vehicle 20 as an embodiment of the present invention. As shown in the drawing, the electric vehicle 20 of the embodiment includes a motor 22 that can input and output power to a drive shaft 32 connected to drive wheels 30 a and 30 b via a differential gear 31, and an inverter 24 that drives the motor 22. A battery 26 that exchanges electric power with the motor 22, an electronic control unit 40 that controls the entire vehicle, and a navigation system 60 that communicates with the electronic control unit 40.

  The motor 22 is configured as a PM type synchronous generator motor including a rotor having a permanent magnet attached to the outer peripheral surface and a stator around which a three-phase coil is wound. The inverter 24 is configured by six switching elements, converts the DC power supplied from the battery 26 into pseudo three-phase AC power, and supplies the pseudo three-phase AC power to the motor 22.

  The electronic control unit 40 is configured as a microprocessor centered on a CPU. In addition to the CPU 42, a ROM 44 for storing processing programs, a RAM 46 for temporarily storing data, an input / output port and a communication port (not shown), Is provided. The electronic control unit 40 includes a rotation position θm from the rotation position detection sensor 23 that detects the rotation position of the motor 22, a battery temperature tb from the temperature sensor 26a that detects the temperature of the battery 26, an ignition signal from the ignition switch 50, A shift position SP from the shift position sensor 52 that detects the operation position of the shift lever 51, an accelerator opening Acc from the accelerator pedal position sensor 54 that detects the depression amount of the accelerator pedal 53, and a brake that detects the depression amount of the brake pedal 55 The brake pedal position BP from the pedal position sensor 56, the vehicle speed V from the vehicle speed sensor 58, and the like are input via the input port. From the electronic control unit 40, a switching control signal to the switching element of the inverter 24 for driving and controlling the motor 22 is output via an output port.

  Next, the operation of the electric vehicle 20 according to the embodiment thus configured will be described. FIG. 2 is a flowchart showing an example of a drive control routine executed by the electronic control unit 40.

  When the drive control routine is executed, the CPU 42 of the electronic control unit 40 firstly has the accelerator opening Acc from the accelerator pedal position sensor 54, the vehicle speed V from the vehicle speed sensor 58, and the motor rotational position θm from the rotational position detection sensor 23. Data necessary for control is input (step S100), and a required torque Td * to be output to the drive shaft 32 is set based on the input accelerator opening Acc and the vehicle speed V (step S110). Here, in the embodiment, the required torque Td * is determined in advance by storing the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Td * in the ROM 44 as a required torque setting map. When the vehicle speed V is given, the corresponding required torque Td * is derived from the stored map and set. An example of the required torque setting map is shown in FIG.

  Subsequently, based on the vehicle speed V, it is determined whether or not the vehicle is substantially stopped (step S120). Here, whether or not the vehicle is substantially stopped is determined based on whether or not the absolute value of the vehicle speed V is equal to or lower than a vehicle speed (for example, 2 km / hour) at which it can be determined that the vehicle is substantially stopped. And Whether or not the vehicle is substantially stopped is determined by a current concentration state in which current concentrates and flows in a specific phase of each phase coil of the motor 22 when the vehicle is substantially stopped. This is because the inverter 24 may reach a high temperature. When the vehicle is not substantially stopped, it is determined that the current is not concentrated, and the required torque Td * is set as the torque command Tm * of the motor 22 (step S130), and the motor is set with the set torque command Tm *. Switching control of the switching element of the inverter 24 is performed so that 22 is driven (step S140), and the drive control routine is terminated. As described above, when the vehicle is not substantially stopped, control for outputting the required torque Td * to be output to the drive shaft 32 from the motor 22 is executed.

  When the vehicle is substantially stopped (step S120), the required torque Td * is compared with a threshold value T1 as an upper limit value of torque that can allow the motor 22 and the inverter 24 to generate heat (step S150). When the required torque Td * is equal to or less than the threshold value T1, even if a torque based on the required torque Td * is output from the motor 22, the current flowing through each phase coil of the motor 22 is small, so that the inverter 24 and the motor 22 may reach a high temperature. If it is determined that there is no, the processes of steps S130 and S140 are executed, and this routine is terminated. Thus, when the required torque Td * is equal to or less than the threshold value T1 when the vehicle is stopped, control for outputting the power based on the required torque Td * from the motor 22 is executed.

  On the other hand, when the required torque Td * is greater than the threshold T1 (step S150), if the measurement of the duration tmd in which the request torque Td * is greater than the threshold T1 has not started, the measurement of the duration tmd is started ( In step S160), the threshold tref1 is compared as the upper limit of the time during which heat generation of the motor 22 and the inverter 24 can be permitted even if the output of the required torque Td * is continued from the motor 22 (step S170). When the duration tmd is equal to or less than the threshold value tref1, it is determined that the motor 22 and the inverter 24 are not damaged by heat even if the output of the torque based on the required torque Td * is continued from the motor 22, and steps S130 and S140 are performed. The process is executed and this routine is terminated. As described above, when the duration tmd during which the requested torque Td * is greater than the threshold value T1 is equal to or less than the threshold value tref1, control for outputting torque based on the requested torque Td * from the motor 22 is executed.

  On the other hand, when the duration tmd exceeds the threshold value tref1 (step S170), it is determined that there is a possibility that the motor 22 or the inverter 24 may be damaged by heat if the control for outputting the required torque Td * from the motor 22 is continued. Then, the torque decrease / increase control illustrated in FIG. 4 is executed (step S180). After the torque decrease / increase control is executed, the duration tmd is reset (step S190), and this routine is terminated.

  Next, the torque decrease / increase control executed in step S180 will be described. FIG. 4 is a flowchart illustrating an example of a torque decrease / increase control routine. When the torque decrease / increase control routine is executed, the accelerator opening degree Acc and the rotation position θm of the rotor of the motor 22 input in the process of step S100 of the drive control routine illustrated in FIG. That is, the accelerator opening when the condition for executing the torque reduction control is satisfied, the accelerator opening Acci when the condition is satisfied as the rotational position of the rotor of the motor 22, and the rotational position θmi when the condition is satisfied are set (step S300). ), Whether or not the flag F is set to 0 is checked (step S310). Here, the flag F is set to a value of 1 during execution of control for increasing torque from the motor 22 described later, and a value of 0 is set as an initial value. Therefore, when execution of this routine is started and step S310 is executed first, the flag F is set to 0.

  When the flag F is 0, the current rotation position θm of the rotor of the motor 22 is input (step S320), and the difference between the rotation position θm and the rotation position θmi when the condition is satisfied is determined as the current of the motor 22. Is compared with the amount of rotation dθref of the motor necessary for the phase in which is concentrated to switch to another phase (step S330). That is, here, it is determined whether or not the rotor of the motor 22 has rotated to such an extent that the phase in which the current of the motor 22 is concentrated switches from the phase in which the current is concentrated to another phase when the routine is started. Judgment.

  When the difference between the rotational position θm and the rotational position θmi when the condition is satisfied is less than the rotational amount dθref, that is, from the phase in which the current is concentrated when the current of the motor 22 is concentrated. When it is not switched to another phase, torque reduction control for reducing the torque from the motor 22 is executed.

  In the torque reduction control, if the measurement of the torque reduction time td as the elapsed time from the start of the torque reduction control is not started, the measurement of the torque reduction time td is started (step S340), and the torque reduction time td The threshold value tref2 is compared (step S350). Here, the threshold value tref2 is set as a time during which the heat generation of the motor 22 and the inverter 24 can be sufficiently suppressed when the torque from the motor 22 is reduced with a torque reduction rate Rd1 described later.

  When the torque reduction time td is equal to or less than the threshold value tref2 (step S350), the torque reduction rate Rd1 (for example, 0. 0) that the torque from the motor 22 quickly suppresses the heat generation of the motor 22 and the inverter 24 with respect to the torque reduction time td. 4) A value obtained by multiplying the torque reduction rate Rd1 by the torque reduction time td from the required torque Td * so as to decrease in accordance with 4) is set as the torque command Tm * of the motor 22 (step S360), and the set torque command Tm * Is used to control the motor 22 (step S390).

  Subsequently, the current accelerator opening Acc is input (step S400), and the absolute value of the difference between the input current accelerator opening Acc and the accelerator opening Acci when the condition is satisfied and the driving request by the driver have changed. The threshold value dAref of the change amount of the accelerator opening Acc to be determined is compared (step S410). When the absolute value of the difference between the current accelerator opening Acc and the accelerator opening Acci when the condition is satisfied is equal to or less than the threshold value dAref, it is determined that the driver's drive request has not changed, and the process returns to step S310. Processing of steps S310 to S360, S390 to S410 until the difference between the rotation position θm and the rotation position θmi when the condition is satisfied is equal to or greater than the threshold value dθref (step S330) or until the torque reduction time td exceeds the threshold value tref2 (step S350). The motor 22 is driven so that the torque from the motor 22 decreases from the required torque Td * with the torque reduction rate Rd1. By driving the motor 22 in this manner, the amount of current flowing through the motor 22 is gradually reduced, so that heat generation of the motor 22 and the inverter 24 can be suppressed and damage due to heat of the motor 22 and the inverter 24 can be suppressed. At this time, since the torque from the motor 22 decreases from the required torque Td *, the vehicle moves backward and the rotor of the motor 22 connected to the drive shaft 32 rotates.

  When the torque reduction time td has passed the threshold value tref2 (step S350), the torque reduction rate Rd2 is set as the torque reduction rate when the torque from the motor 22 is reduced (step S370), and the currently set motor The torque obtained by reducing the torque command Tm * of 22 by the torque reduction rate Rd2 is set as the motor torque command Tm * (step S380). Here, the torque reduction rate Rd2 is stored in the ROM 74 as a torque reduction rate setting map by predetermining the relationship between the currently set torque command Tm * of the motor 22 and the accelerator opening degree Acci when the condition is satisfied in the embodiment. In addition, when the currently set torque command Tm * of the motor 22 and the accelerator opening degree Acci when the condition is satisfied are given, the corresponding torque reduction rate Rd2 is set from the stored map. FIG. 5 shows an example of the torque reduction rate setting map. Here, the torque reduction rate Rd2 is set so as to increase as the accelerator opening at the time of stopping (accelerator opening Acci when the condition is satisfied) increases and as the currently set torque command Tm * of the motor 22 increases. The torque reduction rate Rd2 is set so as to increase as the accelerator opening at the time of stopping (accelerator opening Acci when the condition is satisfied) is larger. The accelerator opening at the time of stopping (accelerator opening Acci when the condition is satisfied) is larger. As a result, it is determined that the driving demand by the driver is large, and by quickly reducing the torque from the motor 22 and quickly reversing the vehicle, priority is given to quickly exiting the current concentration state rather than the riding comfort. It is judged that the driver's drive request is smaller as the accelerator opening (accelerator opening Acci at the time when the condition is satisfied) is smaller, the torque from the motor 22 is slowly decreased, the vehicle is slowly moved backward, and the current concentration state is changed. This is because priority is given to ride comfort over exiting quickly. Further, the torque reduction rate Rd2 is set to increase as the torque command Tm * of the motor 22 currently set increases. The motor 22 increases as the torque command Tm * of the motor 22 currently set increases. This is because priority is given to the suppression of heat generation of the motor 22 over the ride comfort, and the torque reduction rate Rd2 is set to tend to decrease as the currently set torque command Tm * of the motor 22 decreases. The reason is that, as the torque command Tm * of the motor 22 that is currently set is larger, the current flowing through the motor 22 is smaller. Therefore, the vehicle is slowly moved backward so that the ride comfort is prioritized over the heat generation of the motor 22. It is.

 When the torque command Tm * is set, the motor 22 is controlled using the torque command Tm * thus set (step S390), and the absolute value of the difference between the input accelerator opening Acc and the accelerator opening Acci when the condition is satisfied is a threshold value. When it is equal to or less than dAref (steps S400 and S410), the process returns to step S310 until the difference between the rotation position θm of the rotor of the motor 22 and the rotation position θmi when the condition is satisfied is equal to or greater than the threshold value dθref (step S330). Steps S310 to S350 and steps S370 to S410 are repeated. Thus, since the motor 22 is driven so that the torque from the motor 22 decreases with the torque reduction rate Rd2, the vehicle further moves backward and the rotor of the motor 22 connected to the ring gear shaft 32a as the drive shaft rotates. become. At this time, the larger the accelerator opening Acci when the condition is established and the larger the currently set torque command Tm * of the motor 22, the quicker the torque from the motor 22 is reduced and the vehicle is quickly moved backward. The phase in which the current is concentrated among the phase coils of the motor 22 can be quickly switched, heat generation in the motor 22 can be more quickly suppressed, and torque from the motor 22 can be reduced, which will be described later. It is possible to quickly switch to control that increases the torque. Further, as the accelerator opening Acci when the condition is satisfied is smaller, and as the torque command set when the routine is executed is smaller, the torque from the motor 22 is gradually decreased and the vehicle is slowly moved backward. , The ride comfort can be improved.

  When the control for reducing the torque from the motor 22 is being executed in this way, when the difference between the current rotational position θm of the rotor of the motor 22 and the rotational position θmi when the condition is satisfied becomes equal to or greater than the threshold value dθref (step S330), since the rotor of the motor 22 is rotated by the backward movement of the vehicle and the phase in which the current is concentrated among the respective phase coils of the motor 22 is switched to the other phase, it is determined that it is not necessary to further reverse the vehicle. Subsequently, torque increase control for increasing the torque from the motor 22 after step S420 is executed.

  In the torque increase control, first, the measurement of the torque increase time ti as the elapsed time from the start of the torque increase control is started (step S420), and the currently set torque command Tm * is changed to the torque command at the start of increase. It is set as Tmi (step S430), and a value 1 is set to a flag F indicating that control for increasing the torque from the motor 22 is being executed (step S440).

  Subsequently, an estimated gradient value θ as an estimated value of the road surface gradient is calculated from the following equation (1) using the required torque Td * and the vehicle weight M set in step S110 of the drive control routine illustrated in FIG. (Step S450), a torque increase rate Ri for increasing the torque from the motor 22 is set (Step S460). Here, in the embodiment, the torque increase rate Ri is stored in the ROM 74 as a torque increase rate setting map by predetermining the relationship between the estimated gradient value θ, the accelerator opening when the condition is satisfied, and the torque increase rate Ri. When the estimated gradient position θ and the accelerator opening degree Acci when the condition is satisfied are given, the corresponding torque increase rate Ri is set from the stored map. FIG. 6 shows an example of the torque increase rate setting map. Here, the torque increase rate Ri is set so as to increase as the estimated gradient value θ decreases and to increase as the accelerator opening Acc when the vehicle stops (accelerator opening Acci when the condition is satisfied) increases. The reason why the torque increase rate Ri is set to increase as the estimated gradient value θ decreases is based on the following reason. In general, the smaller the accelerator operation amount, the smaller the driver's request for driving.However, even when the accelerator operation amount is small, the driver requests driving instead of stopping when the vehicle stops on a gentle slope. It may be thought that On the contrary, even when the accelerator operation amount is large, when the vehicle is stopped on a steep road surface, it may be considered that the driver is requesting a stop instead of driving the vehicle. Therefore, when the accelerator operation amount Acci is constant, it is considered that the driver's drive request is larger as the estimated gradient value θ is smaller, and the torque increase rate Ri is increased so that the torque from the motor 22 is rapidly increased to quickly move the vehicle. The driving request is prioritized over the ride comfort, and the driver's driving request is considered to be smaller as the estimated gradient value θ increases, and the torque increase rate Ri is decreased to increase the torque from the motor 22 slowly. This is because the ride quality is given priority over the driving demand by stopping the vehicle slowly. The torque increase rate Ri is set so as to increase as the accelerator opening Acc when the vehicle stops (accelerator opening Acci when the condition is satisfied) increases. Considering that the demand is large, the torque from the motor 22 is quickly increased to give priority to the driving request over the ride comfort. The smaller the accelerator opening Acc at the time of stop is, the smaller the driving demand of the driver is. This is because the torque is slowly increased so that the ride comfort is given priority over the driving demand.

  θ = arcsin (Td * / (M ・ g)) (1)

  When the torque increase rate Ri is set in this way, a value obtained by multiplying the torque start time Ti and the torque increase rate Ri by the torque increase time ti so that the torque from the motor 22 increases with the torque increase rate Ri as the torque increase time ti elapses. Is set as the torque command Tm * of the motor 22 (step S470), and the set torque command Tm * is compared with the required torque Td * (step S480). When the set torque command Tm * is less than or equal to the required torque Td *, the motor is controlled using the torque command Tm * (step S390), and the absolute value of the current accelerator opening degree Acc and the accelerator opening degree Acci when the condition is satisfied. When the value difference is less than the threshold value dAref (steps S400 and S410), the process returns to step S310, and it is determined whether or not the flag F is 0 (step S310). Since the flag F is set to the value 1 while the torque increase control is being executed, the processing after step S450 is executed, and the set motor torque command Tm * exceeds the required torque Td *. Until (step S480), the processes of steps S310, S450 to S480, S390 to S410 are executed, and the torque from the motor 22 is increased to suppress the reverse of the vehicle. When the set motor torque command Tm * exceeds the required torque Td * or more (step S480), the flag F is reset to 0 (step S490), and this routine ends. Thus, by increasing the torque output from the motor 22, the vehicle can be stopped, and the next time the accelerator pedal 53 is depressed can be prepared.

  When the control to increase or decrease the torque from the motor 22 is performed, when the difference between the absolute values of the current accelerator opening Acc and the accelerator opening Acci when the condition is satisfied is equal to or greater than the threshold value dAref (steps S400 and S410). ), It is determined that the driver's drive request has changed, the flag F is reset to 0 (step S490), and this routine is terminated.

  According to the electric vehicle 20 of the embodiment described above, after the reverse of the vehicle occurs, the motor has a torque increase rate Ri based on the accelerator opening when stopping (accelerator opening Acci when the condition is satisfied) and the estimated gradient value θ. By increasing the torque output from the motor 22, it is possible to perform control in consideration of the driver's drive request. In addition, the torque increase rate Ri is set so as to become larger as the gradient estimation θ becomes smaller and the accelerator opening at the time of stopping becomes larger. Therefore, the torque output from the electric motor is increased as the driver's driving request becomes larger. Since it can be increased rapidly, the torque based on the drive request can be output from the electric motor more quickly when the driver makes a drive request next time.

  In the electric vehicle 20 of the embodiment, the estimated gradient value θ is calculated based on the required torque Td * and the vehicle weight M, but any estimated physical value that reflects the road surface gradient is used. θ may be calculated, or a gradient sensor that measures the gradient of the road surface may be provided, and a detected value directly detected by the gradient sensor may be used as the estimated gradient value θ.

  In the electric vehicle 20 according to the embodiment, the motor torque command Tm * is decreased by the torque decrease rate Rd1 that quickly suppresses the heat generation in the motor MG2 and the inverter 41 until the torque decrease time td exceeds the threshold value tref2, and then the accelerator is opened when the condition is satisfied. Although the torque reduction rate Rd2 based on the degree Acci and the required torque Td * is reduced, the torque from the motor MG2 is immediately driven without driving the motor MG2 so that the motor torque command Tm * is reduced at the torque reduction rate Rd1. The motor MG2 may be driven so as to decrease at a torque reduction rate Rd2.

  In the electric vehicle 20 according to the embodiment, in the drive control routine illustrated in FIG. 2, the duration tmd during which the requested torque Td * continues to exceed the threshold T1 when the vehicle is stopped is greater than the threshold tref1. 4 is executed to decrease the torque from the motor MG2, but the required torque Td * exceeds the threshold T1 when the vehicle is stopped. Sometimes, the torque decrease / increase control routine illustrated in FIG. 4 may be executed immediately.

  In the embodiment, the electric vehicle 20 including the motor 22 that can input and output power to the drive shaft 32 and the battery 26 that exchanges electric power with the motor 22 has been described, but in addition to the motor 22 and the battery 26, FIG. As exemplified in the electric vehicle 120 of the modification, the present invention may be applied to the electric vehicle 120 in which the engine 122 and the motor 124 are connected to the drive shaft 32 via the planetary gear mechanism 126, or the modification of FIG. As illustrated in the electric vehicle 220, the engine includes an engine 222, an inner rotor 232 connected to the crankshaft of the engine 222, and an outer rotor 234 connected to the drive shaft 32 connected to the drive wheels 30a and 30b. A counter-rotor motor 230 that transmits a part of the power of the engine 222 to the drive shaft 32 and converts the remaining power into electric power; It may alternatively be applied to an electric vehicle 220 equipped. Moreover, although the Example demonstrated the electric vehicle 20 which can drive | work with the motive power from the motor 22 as a motive power source, you may apply to the motor vehicle which can drive | work with the motive power from the internal combustion engine as a motive power source. Moreover, it is good also as a form of the control method of such a vehicle.

  Here, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the motor 22 that can output power to the axle connected to the drive shaft 32 corresponds to an “electric motor”, and an accelerator position sensor 54 that detects an accelerator operation amount of the driver is an “accelerator operation amount detection means”. The electronic control unit 40 that executes the processing of step S110 for setting the required torque Td * required for traveling based on the accelerator operation amount corresponds to “required driving force setting means”, and the set required torque Td. The duration tmd during which the processing of steps S130 and S140 for controlling the motor 22 to output torque based on * and the state where the required torque Td * is greater than the threshold T1 while the vehicle is stopped is longer than the threshold tref1. Sometimes the processing of steps S120 and S150 to S190 for executing the torque decrease / increase control routine illustrated in FIG. The motor 22 is controlled so that the torque output from the motor 22 decreases with the torque reduction rate Rd1 or the torque reduction rate Rd2 until the rotational position θm of the motor becomes equal to or greater than the threshold value dθref on the condition that the cell operation amount Acc does not change. Processing in steps S310 to S410, processing in step S460 for setting the torque increase rate Ri based on the accelerator opening degree Acci and the estimated gradient value θ when the condition is satisfied when the rotational position θm of the motor becomes equal to or greater than the threshold value dθref, motor 22 The electronic control unit 40 that sets the motor torque command Tm * so that the torque output from the motor increases at the set torque increase rate Ri and controls the motor 22 and executes the processes of steps S470, S480, and S390 is "control means". Is equivalent to. The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. It is an example for specifically explaining the best mode for doing so, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  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 is applicable to a vehicle manufacturing industry or the like.

It is a block diagram which shows the outline of a structure of the electric vehicle 20 as one Example of this invention. It is a flowchart which shows an example of the drive control routine performed by the electronic control unit 40 of an Example. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows an example of the torque reduction increase control routine performed by the electronic control unit 40 of an Example. It is explanatory drawing which shows an example of the map for torque reduction rate setting. It is explanatory drawing which shows an example of the map for torque increase rate setting. 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.

Explanation of symbols

  20, 120, 220 Electric vehicle, 22 Motor, 23 Rotation position detection sensor, 24 Inverter, 26 Battery, 30a, 30b Drive wheel, 31 Differential gear, 32 Drive shaft, 40 Electronic control unit, 42 CPU, 44 ROM, 46 RAM , 50 ignition switch, 51 shift lever, 52 shift position sensor, 53 accelerator pedal, 54 accelerator pedal position sensor, 55 brake pedal, 56 brake pedal position sensor, 58 vehicle speed sensor, 122, 222 engine, 124 motor, 126 planetary gear mechanism 230 rotor motor, 232 inner rotor, 234 outer rotor.

Claims (7)

An electric motor capable of outputting power to the axle, an accelerator operation amount detection means for detecting an accelerator operation amount, a gradient reflection physical quantity detection means for detecting a gradient reflection physical quantity that is a physical quantity reflecting a road surface gradient, and the accelerator operation amount In a vehicle comprising: required driving force setting means for setting required driving force required for traveling; and control means for controlling the electric motor so that torque based on the set required driving force is output from the electric motor. ,
When the predetermined torque decrease / increase condition is satisfied in a state where the vehicle is substantially stopped, the control means is configured until the predetermined reverse movement occurs in the vehicle on the condition that the detected accelerator operation amount does not change. The motor is controlled so that the torque output from the motor decreases with a first amount of change, and the torque output from the motor after the predetermined reverse movement is detected as the detected accelerator operation amount. A vehicle for controlling the electric motor so as to increase with a second change amount based on the gradient reflected physical quantity.   2. The vehicle according to claim 1, wherein the second change amount is set to increase as the road surface gradient based on the detected gradient reflecting physical quantity decreases and as the detected accelerator operation amount increases.   The vehicle according to claim 1, wherein the first change amount is set based on the detected accelerator operation amount.   The vehicle according to any one of claims 1 to 3, wherein the first change amount is set based on the set required driving force.   5. The vehicle according to claim 1, wherein the predetermined torque decrease / increase condition is a condition in which a torque greater than a predetermined torque is output from the electric motor for a predetermined time or more. An electric motor capable of outputting power to the axle, an accelerator operation amount detection means for detecting an accelerator operation amount, a gradient reflection physical quantity detection means for detecting a gradient reflection physical quantity that is a physical quantity reflecting a road surface gradient, and the accelerator operation amount A required driving force setting means for setting a required driving force required for traveling, and a control means for controlling the electric motor so that torque based on the set required driving force is output from the electric motor. In the drive device mounted on
When the predetermined torque decrease / increase condition is satisfied in a state where the vehicle is substantially stopped, the control means is provided until the predetermined reverse occurs in the vehicle on the condition that the detected accelerator operation amount does not change. The motor is controlled so that the torque output from the motor decreases with a first change amount, and the torque output from the motor after the predetermined reverse movement is detected as the detected accelerator operation amount. A drive device that controls the electric motor so as to increase with a second change amount based on the gradient reflected physical quantity. In a vehicle including an electric motor capable of outputting power to an axle, a required driving force required for traveling is set based on an accelerator operation amount, and the torque based on the set required driving force is output from the electric motor. In a vehicle control method for controlling an electric motor,
When a predetermined torque increase condition is satisfied when the vehicle is substantially stopped, the torque output from the electric motor until the predetermined reverse occurs on the vehicle on the condition that there is no change in the accelerator operation amount. The electric motor is controlled so as to decrease with a change amount of 1, and after the predetermined backward movement occurs, the torque output from the electric motor is based on the accelerator operation amount and a gradient reflecting physical quantity that is a physical quantity reflecting the road surface gradient. A method for controlling a vehicle, wherein the electric motor is controlled to increase with a second amount of change.

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