JP2013027107A - Device for controlling on-vehicle electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow wheels to ride over a level difference as much as possible while adequately protecting components of an electric motor or the like.SOLUTION: When a hybrid vehicle travels using a second motor generator 5, torque reduction processing for reducing a torque of the second motor generator 5 is carried out in a case where wheels 11 cannot ride over a level difference on a road surface and rotation stop may be caused. In the torque reduction processing, a start timing of reducing the torque of the second motor generator 5 and a reduction amount of the torque per unit time are changed according to a gradient of the level difference on a road surface. Accordingly, reduction of the torque can be appropriately performed according to a gradient of the level difference. By appropriately performing reduction of the torque according to a gradient of a level difference, such troubles that reduction of the torque is insufficient to protect components of the second motor generator 5 or the like and the wheels 11 cannot ride over a level difference due to excessive reduction of the torque can be prevented.

Description

  The present invention relates to an on-vehicle motor control device.

  Vehicles such as electric vehicles and hybrid vehicles travel by rotating wheels with an electric motor. During traveling of a vehicle by driving such an electric motor, for example, as shown in Patent Document 1, a wheel may reach a step on a road surface. In this way, when the wheel reaches the step, if the wheel stops rotating without overcoming the step, current flows through the electric motor and the electric circuit for driving the electric motor. There is a risk of malfunction due to heat generation. Therefore, when it is intended to protect the parts from such a failure and the wheel is going over the road step, if there is a possibility that the wheel stops at the same step, it is conceivable to reduce the torque of the motor.

JP 2008-13113 (paragraph [0002])

  As described above, when the wheel tries to get over the step on the road surface, if there is a possibility that the wheel may stop at the step, if the torque of the motor is reduced, it flows to the motor and the electric circuit for driving the motor. Since the current is reduced, it is possible to suppress failure of the electric motor and the electric circuit due to the heat generation. However, if the torque of the motor is not properly reduced, the torque will be excessively reduced, and even if the parts such as the motor and the electric circuit can be protected from the above-mentioned failure, the wheels may have a step difference. You may not be able to get over.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an in-vehicle electric motor capable of overcoming a step as much as possible while accurately protecting components such as an electric motor. It is to provide a control device.

  According to the first aspect of the present invention, when a wheel rotating by driving an electric motor mounted on a vehicle gets over a step on the road surface, if there is a possibility that the wheel stops at the step, the protection of parts such as the electric motor is protected. Intentionally, the torque of the electric motor is reduced by the torque reduction means. Thus, when reducing the torque of the electric motor, the amount of reduction of the torque per unit time is changed according to the gradient of the step on the road surface. Thereby, the torque can be appropriately reduced according to the gradient of the step. And by appropriately reducing the torque according to the gradient of the step, the torque is insufficiently reduced to protect parts such as an electric motor, or the torque is excessively reduced and the wheel It is possible to suppress the inability to get over the steps. As a result, it is possible to allow the wheel to get over the step as much as possible while accurately protecting the components such as the electric motor.

  According to the second aspect of the present invention, when the torque of the motor is reduced by the torque reduction means, when the slope of the road surface step is greater than or equal to the reference value, the torque is less than when the slope is less than the reference value. The reduction start timing is delayed, and the reduction amount per unit time of the same torque is increased. Here, when the gradient of the step is a large value such as a reference value or more, it is difficult for the wheel to get over the step. However, at this time, the torque reduction start timing is delayed so that the wheel can get over the step as much as possible. However, there is a possibility that the period during which current flows through the motor with the wheels stopped rotating at a level difference will cause a failure due to heat generation in components such as the motor and the electric circuit for driving the motor. Is inevitable. Considering this, when the slope of the step is equal to or higher than the reference value, the amount of reduction per unit time of the torque is increased in accordance with the fact that the torque reduction start timing is delayed. Thereby, while suppressing failure of parts such as an electric motor by delaying the torque reduction start timing, the wheels can get over the step as much as possible by delaying the torque reduction start timing. On the other hand, when the slope of the step is a small value less than the reference value, the wheel easily gets over the step, so the timing for starting the torque reduction is not delayed and the amount of reduction of the torque per unit time is large. It is never done. As described above, it is possible to allow the wheel to get over the step as much as possible while accurately protecting the components such as the electric motor.

  Note that when the road surface level difference is equal to or greater than the reference value, the method of delaying the torque reduction start timing is employed as compared with the case where the level difference is less than the standard value. It is preferable. According to the third aspect of the invention, when the integrated value of the drive current of the motor after it is determined that there is a possibility that the wheel may stop at a step on the road surface, the torque reduction of the motor starts. Is done. When the gradient of the step is greater than or equal to the reference value, the threshold value is made larger than when the gradient is less than the reference value.

  According to the fourth aspect of the present invention, the accelerator operation of the driver of the vehicle is performed until it is determined that there is a possibility that the wheel may stop at a step on the road surface until the torque of the motor is started to be reduced by the torque reducing means. The torque of the based motor is increased by the control means. As described above, by increasing the torque of the electric motor before starting the torque reduction of the electric motor by the torque reducing means, it becomes easier for the wheel to get over the step.

  According to the fifth aspect of the present invention, when a wheel rotating by driving an electric motor mounted on a vehicle gets over a step on the road surface, if there is a possibility that the wheel stops at the step, protection of parts such as the electric motor is protected. Intentionally, the torque of the electric motor is reduced by the torque reduction means. Thus, when reducing the torque of the motor, the torque reduction start timing is changed according to the gradient of the road surface level difference. Thereby, the torque can be appropriately reduced according to the gradient of the step. And by appropriately reducing the torque according to the gradient of the step, the torque is insufficiently reduced to protect parts such as an electric motor, or the torque is excessively reduced and the wheel It is possible to suppress the inability to get over the steps. As a result, it is possible to allow the wheel to get over the step as much as possible while accurately protecting the components such as the electric motor.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows the structure of the hybrid vehicle to which the control apparatus of this embodiment is applied. The graph which shows the change of the accelerator operation amount for control with respect to the change of the actual accelerator operation amount. The flowchart which shows the execution procedure of a torque reduction process. The flowchart which shows the setting procedure of the flag F, a threshold value, and a luc reduction inclination. The schematic diagram which shows the state which the wheel contacted the level | step difference of a road surface. (A) And (b) is a time chart which shows the reduction aspect of the torque of a 2nd motor generator, and the transition aspect of the integrated value of the drive current of a 2nd motor generator.

Hereinafter, an embodiment in which the present invention is applied to a hybrid vehicle equipped with an internal combustion engine and a motor as a prime mover will be described with reference to FIGS.
In the hybrid vehicle shown in FIG. 1, the power output from the internal combustion engine 1 is transmitted to the first motor generator 4 and the power transmitted to the drive shaft 3 of the vehicle by a power split mechanism 2 including a planetary gear or the like. Divided into power. The power output from the second motor generator 5 is also transmitted to the drive shaft 3 of the hybrid vehicle. When the wheels 11 connected to the drive shaft 3 are rotated by the transmission of power to the drive shaft 3, the hybrid vehicle travels.

  The first motor generator 4 functions mainly as a generator, but also functions as a motor depending on the driving state of the hybrid vehicle. The second motor generator 5 mainly functions as a motor, but also functions as a generator depending on the operating state of the hybrid vehicle. The hybrid vehicle is provided with an inverter 7 that controls input / output of electric power between the battery 6 and the first and second motor generators 4, 5. The inverter 7 supplies, for example, electric power obtained by the first motor generator 4 that functions mainly as a generator to the battery 6 to charge the battery 6, and also functions as a second motor that mainly functions as a motor. Electric power is supplied from the battery 6 to the motor generator 5.

  The hybrid vehicle is provided with an electronic control unit 15 that controls various devices mounted on the vehicle. The electronic control unit 15 includes a CPU that executes arithmetic processing related to the control of the various devices, a ROM that stores programs and data necessary for the control, a RAM that temporarily stores the arithmetic results of the CPU, and the like. It has input / output ports for inputting and outputting signals between them. An input port of the electronic control unit 15 includes an accelerator position sensor 9 that detects an operation amount (accelerator operation amount) of an accelerator pedal 8 that is operated by a driver of the hybrid vehicle, and a vehicle speed sensor 10 that detects a vehicle speed of the hybrid vehicle. Various sensors are connected. On the other hand, in the output port of the electronic control unit 15, drive circuits for various devices for operating the internal combustion engine 1, drive circuit for the first motor generator 4, drive circuit for the second motor generator 5, and drive circuit for the inverter 7. Etc. are connected.

  The electronic control unit 15 obtains the vehicle required power in the hybrid vehicle based on the driving state such as the vehicle speed and the accelerator operation amount, the power output from the internal combustion engine 1 and the second motor generator so as to obtain the obtained vehicle required power. The power output from 5 is controlled. Such control of the internal combustion engine 1 and the second motor generator 5 is performed in consideration of minimizing energy consumption associated with the driving thereof. For example, when the hybrid vehicle is traveling at a low speed, the operation of the internal combustion engine 1 is stopped while the second motor generator 5 is functioning as a motor, so that only the second motor generator 5 travels. Further, when the hybrid vehicle is accelerated, the internal combustion engine 1 is also operated while the second motor generator 5 functions as a motor, so that the second motor generator 5 and the internal combustion engine 1 travel together.

  Here, the vehicle required power for controlling the power output from the internal combustion engine 1 or the second motor generator 5 is required to increase as the accelerator operation amount increases by the driver. The increasing tendency of the required vehicle power based on the increase in the accelerator operation amount is made variable according to the mode selection by the driver or the like among the power mode, normal mode, and economy mode. Specifically, with respect to changes in the actual accelerator operation amount by the driver, the control accelerator operation amount for obtaining the vehicle required power differs as indicated by the solid lines L1 to L3 in FIG. Vary in the manner. That is, when the power mode is selected, the control accelerator operation amount is changed as indicated by the solid line L1 with respect to the actual change in the accelerator operation amount. When the normal mode is selected, the control accelerator operation amount is changed as indicated by the solid line L2 with respect to the actual change in the accelerator operation amount. Further, when the economy mode is selected, the control accelerator operation amount is changed as indicated by the solid line L3 with respect to the actual change in the accelerator operation amount. As described above, since the vehicle required power is obtained based on the control accelerator operation amount that changes in a different manner with respect to the actual change in the accelerator operation amount according to each mode, the change in the vehicle required power with respect to the actual change in the accelerator operation amount. The mode is variable according to each mode. More specifically, the required vehicle power based on the actual accelerator operation amount is increased in the order of economy mode, normal mode, and power mode.

  By the way, in the hybrid vehicle, the wheel 11 may reach a step on the road surface while traveling by the second motor generator 5. When the wheel 11 approaches the step as described above, if the wheel 11 stops rotating without overcoming the step, a current flows through the electric circuit including the second motor generator 5 and the inverter 7 for driving the second motor generator 5. As a result, the second motor generator 5 and the electric circuit may be damaged due to heat generation. Therefore, when the wheel 11 tries to get over the road step with the intention of protecting the parts from such a failure, the torque of the second motor generator 5 is reduced when the wheel 11 may stop at the same step. Torque reduction processing is executed. When the torque of the second motor generator 5 is reduced by this torque reduction process, the current flowing through the second motor generator 5 and the electric circuit for driving the second motor generator 5 is reduced. It can suppress that a circuit fails by the said heat_generation | fever.

  In the torque reduction process, when the torque of the second motor generator 5 is reduced, the torque reduction start timing and the amount of reduction of the torque per unit time are changed according to the gradient of the road surface step. Thereby, the torque can be appropriately reduced according to the gradient of the step. Then, by appropriately performing the torque reduction according to the gradient of the step, the torque reduction becomes insufficient in protecting the components such as the second motor generator 5 or the torque reduction is excessive. Thus, it is possible to prevent the wheel 11 from getting over the step. As a result, it is possible to allow the wheel 11 to get over the step as much as possible while accurately protecting the components such as the second motor generator 5.

  Next, a detailed execution procedure of the torque reduction process will be described with reference to a flowchart of FIG. 3 showing a torque reduction process routine. This torque reduction processing routine is periodically executed by, for example, a time interruption every predetermined time through the electronic control device 15 when the hybrid motor is driven by the second motor generator 5.

  In this routine, it is determined whether or not the flag F for determining whether or not the wheel 11 is in a situation where there is a possibility that the wheel 11 may stop rotating without overcoming the step, is “1 (being over the step)”. Is performed (S101). Regarding the flag F, when it is determined based on the vehicle speed, the driving force acting on the wheels 11, the vehicle acceleration, and the like that the wheels 11 are in a situation where they may stop rotating without overcoming the step, 1 ”. Incidentally, the driving force acting on the wheel 11 is a value obtained from the vehicle required power or the like, and the vehicle acceleration is a value obtained from the rotation speed of the wheel 11 obtained based on the detection value or the like of the vehicle speed sensor 10. On the other hand, when the torque reduction of the second motor generator 5 by the torque reduction process is completed, or when the wheel 11 gets over the step and the torque reduction of the second motor generator 5 by the torque reduction process is not necessary, the torque reduction is completed. In some cases, the flag F is set to “0 (not over the step)”.

  If an affirmative determination is made in the process of S101, it is determined whether or not the hybrid vehicle is in a power mode (S102). If it is determined that the power mode is not selected, the power mode is selected (S103). In this state, the integrated value of the drive current of the second motor generator 5 after the flag F becomes “1” is calculated (S104). Specifically, every time the process of S104 is executed, the current driving current of the second motor generator 5 is accumulated, and the value obtained by such accumulation is accumulated as the driving current of the second motor generator 5. Value. When the integrated value obtained in S104 is equal to or greater than the threshold value (S105: YES), the torque of second motor generator 5 is reduced with a predetermined torque reduction gradient (S106). Here, the torque reduction slope means a torque reduction amount of the second motor generator 5 that is reduced per unit time.

  Then, after the torque reduction process is executed, it is determined whether or not the torque reduction of the second motor generator 5 by the process is completed (S107). Incidentally, the determination that the torque reduction of the second motor generator 5 by the torque reduction processing is completed is made when the torque of the second motor generator 5 is reduced to a predetermined value. If an affirmative determination is made in the process of S107, the flag F is set to “0” (S108), the accumulated value accumulated in S104 is reset to the initial value “0” (S109), and the power mode is selected. Release (S110) is performed.

  Next, for the procedure for setting the flag F to “1”, setting the threshold value used in the process of S105, and setting the torque reduction slope used in the process of S106, refer to the flowchart of FIG. To explain. This setting routine is periodically executed, for example, by a time interruption every predetermined time through the electronic control device 15 when the second motor generator 5 travels the hybrid vehicle.

  In this routine, first, it is determined whether or not there is a possibility that the wheel 11 is approaching the step and may stop rotating without overcoming the step. Here, the determination that the wheel 11 is in a situation where there is a possibility that the wheel 11 may stop rotating without overcoming the step is determined whether the vehicle speed is less than a predetermined value A (S201), and the driving force of the hybrid vehicle is a predetermined value. The determination is made based on whether the determination is positive or not (S202) and whether the acceleration of the hybrid vehicle is less than a predetermined value C (S203). If all the determinations in S201 to S203 are affirmative, it is determined whether or not the flag F is “0 (not over the step)” (S204: YES). In the setting routine, when it is determined for the first time in the processes of S201 to S203 that all are affirmative, an affirmative determination is made in S204 because the flag F is “0”, and the flag F is set to “1 (being over the step)”. It is set (S205).

  After the flag F is set to “1”, the gradient θ of the step which the wheel 11 is about to get over is obtained (S206). Here, the step gradient θ is the inclination angle between the tangent of the wheel 11 and the horizontal plane at the contact portion of the wheel 11 with respect to the step which the wheel 11 is about to get over. Hereinafter, a method of obtaining the step gradient θ will be described in detail with reference to FIG. In addition, the figure has shown typically the state which the wheel 11 contacted the level | step difference of the road surface.

The step gradient θ shown in FIG. 5 is obtained by calculating the step height X using the following equations (1) to (4) and then solving the following equation (5) using the height X. Desired.
X = α + (α ^ 2-4β) ^ 0.5 / 2 (1)
α = 2 · WR (2)
β = {Tp · DEF / (M · WR) −a} ^ 2 / (WR · g) ^ 2 (3)
a = WR · (d / dt) ω (4)
sinθ = (2X · WR−X ^ 2) ^ 0.5 / WR (5)
In Expressions (1) to (5), “^ 2” represents the square, and “^ 0.5” represents the 0.5th power (square root). The term “α” used in the equation (1) is calculated using the equation (2) based on the radius WR of the wheel 11. The term “β” used in the equation (1) is calculated using the equation (3) based on the driving force Tp acting on the vehicle, the gear ratio DEF of the differential gear, the load M acting on the wheel 11, and the gravitational acceleration g. Is done. Equation (4) is for calculating the acceleration a of the vehicle used in Equation (3). That is, based on the time differential value (d / dt) ω of the rotational speed ω of the wheel 11 and the radius WR of the wheel 11, the acceleration a of the vehicle is calculated using Expression (4).

  After the step gradient θ is obtained in S206 of the setting routine of FIG. 4, it is determined whether or not the step gradient θ is equal to or greater than a reference value D that is predetermined by experiment or the like (S207). If it is determined that the step gradient θ is less than the reference value D, the threshold used in the process of S105 of the torque reduction process routine (FIG. 3) is set to “E2”, and S106 of the same routine is set. The torque reduction slope used in the process is set to “F2” (S208). On the other hand, when it is determined in step S207 of FIG. 4 that the gradient θ of the step is equal to or greater than the reference value D, the threshold value is set to “E1” larger than “E2”, and the torque reduction gradient is set. Is set to F1 larger than “F2” (S209).

  Further, the processing of S210 to S214 in the setting routine is for dealing with a situation in which the wheel 11 gets over the step after the wheel 11 reaches the step and the torque reduction processing is executed. This series of processing is executed when a negative determination is made in any one of S201 to S203 based on the fact that the wheel 11 has overcome the step or is traveling on a road surface without the step. Specifically, it is first determined whether or not the flag F is “1 (being over the step)” (S210). If the determination is affirmative, the torque reduction process is terminated (S211). Further, the flag F is set to “0 (not stepped over)” (S212), the accumulated value accumulated in S104 is reset to the initial value “0” (S213), and the power mode selection is canceled (S214). ) Is performed. When the torque reduction process is finished by this series of processes, the torque reduction of the second motor generator 5 is finished. As a result, the normal drive control of the second motor generator 5, in other words, the drive control of the second motor generator 5 for obtaining the vehicle required power corresponding to the accelerator operation amount is performed.

Next, the torque reduction mode of the second motor generator 5 by the torque reduction process will be described in detail with reference to the time chart of FIG.
When the hybrid vehicle is driven by the second motor generator 5, if the wheel 11 approaches a step and the flag F is set to “1 (passing over the step)” (timing T <b> 1), the power mode is set in a mode other than the power mode. Is selected, and the torque of the second motor generator 5 is increased as shown in FIG. The fact that the flag F is set to “1” means that the wheel 11 may stop rotating without getting over the step. Then, the integrated value obtained as the cumulative value of the driving current of the second motor generator 5 after the flag F becomes “1” gradually increases after the timing T1, as shown in FIG. 6B. .

  When the gradient θ of the step is less than the reference value D, the torque reduction of the second motor generator 5 is started by the torque reduction process when the integrated value rises to the threshold value E2 (timing T2). The torque reduction at this time, that is, the torque reduction indicated by the solid line in FIG. 6A is performed with a torque reduction gradient F2. On the other hand, when the gradient θ of the step is equal to or greater than the reference value D, the second motor by the torque reduction process is performed when the integrated value shown in FIG. 6B rises to a threshold value E1 larger than the threshold value E2 (timing T3). Reduction of the torque of the generator 5 is started. The torque reduction at this time, that is, the torque reduction indicated by the broken line in FIG. 6A is performed with a torque reduction slope F1 larger than the torque reduction slope F2.

  As can be seen from the above, when the torque of the second motor generator 5 is reduced through the torque reduction process, when the step gradient θ is greater than or equal to the reference value D, the above gradient θ is less than the reference value D. The torque reduction start timing is delayed, and the reduction amount (torque reduction slope) per unit time of the torque is increased.

  Here, when the gradient θ of the step is a large value such as the reference value D or more, it is difficult for the wheel 11 to get over the step. However, at this time, the torque reduction start timing is delayed from the timing T2 to the timing T3, so that the wheel 11 can get over the step as much as possible. However, there is a possibility that the period during which a current flows through the second motor generator 5 with the wheel 11 stopped rotating at a level difference, the second motor generator 5 and components such as an electric circuit for driving the second motor generator 5 in that case. It is inevitable that a failure due to heat is likely to occur.

  Considering this, when the step gradient θ is greater than or equal to the reference value D, the amount of torque reduction per unit time (torque reduction slope) is reduced in accordance with the delay of the torque reduction start timing. Increased. Thereby, while suppressing failure of components such as the second motor generator 5 due to delaying the torque reduction start timing, the wheel 11 can get over the step as much as possible by delaying the torque reduction start timing. To do. On the other hand, when the step gradient θ is a small value less than the reference value D, the wheel 11 easily gets over the step, and therefore the torque reduction start timing is not delayed to the timing T3. The amount of reduction per hour is not increased.

According to the embodiment described in detail above, the following effects can be obtained.
(1) Torque reduction processing for reducing the torque of the second motor generator 5 when the second motor generator 5 is traveling the hybrid vehicle and there is a possibility that the wheels 11 may stop rotating without getting over the road step. Is executed. In this torque reduction process, the torque reduction start timing of the second motor generator 5 and the amount of torque reduction per unit time (torque reduction slope) are changed in accordance with the road surface gradient θ. Thus, the torque can be appropriately reduced according to the step gradient θ. Then, by appropriately reducing the torque according to the step gradient θ, the torque is insufficiently reduced to protect components such as the second motor generator 5 or the torque is excessively reduced. It can be suppressed that the wheel 11 cannot get over the step. As a result, it is possible to allow the wheel 11 to get over the step as much as possible while accurately protecting the components such as the second motor generator 5.

  (2) When reducing the torque of the second motor generator 5 through the torque reduction process, when the step gradient θ is greater than or equal to the reference value D, the torque is reduced more than when the gradient θ is less than the reference value D. The start timing is delayed, and the reduction amount (torque reduction slope) of the same torque per unit time is increased. Thereby, while suppressing failure of components such as the second motor generator 5 due to delaying the torque reduction start timing, the wheel 11 can get over the step as much as possible by delaying the torque reduction start timing. To do. On the other hand, when the step gradient θ is a small value less than the reference value D, the wheel 11 easily gets over the step, and therefore the torque reduction start timing is not delayed to the timing T3. The amount of reduction per hour is not increased. As described above, it is possible to allow the wheel 11 to get over the step as much as possible while accurately protecting the components such as the second motor generator 5.

  (3) When it is determined that there is a possibility that the wheel 11 may stop at a step on the road surface when the hybrid motor vehicle is driven by the second motor generator 5, the mode other than the power mode is set after the flag F is set to "1". The power mode is selected on the condition that As a result, the torque of the second motor generator 5 based on the accelerator operation from when it is determined that there is a possibility that the wheel 11 may stop at a step on the road surface until the torque of the second motor generator 5 is started to be reduced by the torque reduction process. Is increased. As described above, by increasing the torque of the second motor generator 5 before the torque reduction of the second motor generator 5 by the torque reduction process is started, the wheel 11 easily gets over the step. If the torque of the second motor generator 5 is not increased as described above, when the wheel 11 is approaching the step, if the driver has insufficient increase in the amount of accelerator operation, the wheel 11 has a step. Before getting over, the integrated value of the drive current of the second motor generator 5 rises above the threshold. As a result, the torque of the second motor generator 5 is reduced through the torque reduction process, and a situation occurs in which the wheel 11 cannot get over the step, and the occurrence of such a situation can be suppressed. .

In addition, the said embodiment can also be changed as follows, for example.
When reducing the torque of the second motor generator 5 through the torque reduction process, only the torque reduction start timing may be changed according to the gradient of the road surface step. In this case, when the gradient θ of the step is greater than or equal to the reference value D, it is possible to delay the torque reduction start timing compared to when the gradient θ is less than the reference value D. In this way, by performing the torque reduction according to the step gradient θ, the torque reduction becomes insufficient to protect the components of the second motor generator 5, or the torque reduction becomes excessive. Thus, it is possible to prevent the wheel 11 from getting over the step. As a result, it is possible to allow the wheel 11 to get over the step as much as possible while accurately protecting the components such as the second motor generator 5.

  The torque of the second motor generator 5 based on the accelerator operation until the reduction of the torque of the second motor generator 5 by the torque reduction process is started after it is determined that there is a possibility that the wheel 11 stops at the road surface level difference. Although increased, it is not necessary to perform such torque increase. That is, when the hybrid vehicle is driven by the second motor generator 5, it is necessary to select the power mode after it is determined that there is a possibility that the wheel 11 may stop at a road step and the flag F is set to “1”. However, when the mode is other than the power mode, the same mode may be maintained.

  When reducing the torque of the second motor generator 5 through the torque reduction process, only the reduction amount (torque reduction slope) of the torque per unit time may be changed according to the slope of the road surface step. In this case, when the gradient θ of the step is greater than or equal to the reference value D, the torque reduction gradient can be made smaller than when the gradient θ is less than the reference value D. In this way, by performing the torque reduction according to the step gradient θ, the torque reduction becomes insufficient to protect the components of the second motor generator 5, or the torque reduction becomes excessive. Thus, it is possible to prevent the wheel 11 from getting over the step. As a result, it is possible to allow the wheel 11 to get over the step as much as possible while accurately protecting the components such as the second motor generator 5.

The step gradient θ may be obtained by actual measurement with a sensor or the like instead of by calculation using the equations (1) to (5).
-You may apply this invention to the vehicle which rotates a wheel only with electric motors, such as an electric vehicle, and drive | works.

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Power split mechanism, 3 ... Drive shaft, 4 ... 1st motor generator, 5 ... 2nd motor generator, 6 ... Battery, 7 ... Inverter, 8 ... Accelerator pedal, 9 ... Accelerator position sensor, 10 ... Vehicle speed sensor, 11 ... Wheel, 15 ... Electronic control device (torque reduction means, control means).

Claims (5)

Control of an on-vehicle motor provided with torque reducing means for reducing the torque of the motor when there is a possibility that when the wheel rotating by driving of the motor mounted on the vehicle gets over the road level difference, the wheel may stop at the level difference In the device
The on-vehicle motor control device according to claim 1, wherein the torque reduction means changes the amount of reduction of the torque per unit time according to the gradient of the step when the torque of the motor is reduced. When reducing the torque of the electric motor, the torque reducing means delays the torque reduction start timing when the gradient of the road surface step is greater than or equal to a reference value than when the gradient is less than the reference value. The on-vehicle electric motor control device according to claim 1, wherein the reduction amount of the same torque per unit time is increased. The torque reduction means starts to reduce the torque of the electric motor when the integrated value of the driving current of the electric motor after it is determined that the wheel may stop at a step on the road surface is equal to or greater than a threshold value. The control device for an in-vehicle electric motor according to claim 2, wherein when the gradient of the step is greater than or equal to the reference value, the threshold value is made larger than when the gradient is less than the reference value. In the control apparatus of the vehicle-mounted motor according to any one of claims 1 to 3,
The torque of the electric motor is increased based on the accelerator operation of the driver of the vehicle from when it is determined that the wheel may stop at a step on the road until the torque of the electric motor starts to be reduced by the torque reducing means. A control device for an on-vehicle electric motor, comprising: Control of an on-vehicle motor provided with torque reducing means for reducing the torque of the motor when there is a possibility that when the wheel rotating by driving of the motor mounted on the vehicle gets over the road level difference, the wheel may stop at the level difference In the device
The torque reduction means changes the torque reduction start timing in accordance with a step gradient of the road surface when reducing the torque of the electric motor.

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