JP2019103320A - Vehicle control device and vehicle control method - Google Patents

Abstract

To suppress an impact of stick slip by control without changing a mechanical mechanism.SOLUTION: A vehicle control device includes: target driving force setting means for setting driving force of a vehicle; torque control means for controlling torque output by a motor according to output of the target driving force setting means; a current control device for controlling a driving current of the motor according to output of the torque control means; the motor for driving the vehicle; target braking force setting means for setting braking force of the vehicle; and braking control device for braking the vehicle according to output of the target braking force setting means. Rotation amount control means is provided for determining a rotation amount controlled variable by detecting a state in which braking force and driving force are balanced when one of the driving force and the braking force decreases and the other increases in performing a start operation of the vehicle or performing a stop operation of the vehicle, and the rotation amount controlled variable determined by the rotation amount control means is given to the current control device.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a control device for a vehicle such as an electric vehicle or a hybrid vehicle provided with a motor for driving a vehicle and an inverter for controlling a drive current of the motor, and a control method of the vehicle.

  In recent years, automobiles with low fuel consumption and low displacement have been sought as part of global environmental protection, and automobiles that drive motors by electric power and travel, for example, electric cars, hybrid cars, and fuel cell cars, are attracting attention.

  These vehicles are equipped with at least an electronic control unit (hereinafter simply referred to as an ECU; ECU is an abbreviation of Electronic Control Unit), a motor control unit, and a brake control unit as a system for controlling the driving force and braking force of the vehicle. It is done.

  Among them, the ECU determines the driving force and the braking force necessary for traveling based on the vehicle operation information by the driver and the information from the plurality of sensors mounted on the vehicle, and the motor control device corresponds to the motor corresponding to the driving force. The brake control device requires a braking force corresponding to the braking force.

  The motor control device comprises a motor for driving the vehicle and an inverter for controlling the drive current of the motor, and controls the motor current with the inverter based on the output torque of the motor requested from the ECU, thereby applying torque to the motor. Make it output. The output shaft of the motor and the wheel are connected via a reduction gear, and the torque output by the motor is amplified by the reduction gear and transmitted to the wheel.

  The brake control device includes a disk rotor, a brake pad, and a brake mechanism, and generates a frictional force by pressing the brake pad fixed to the vehicle body against the disk rotor provided on the wheel portion. The force pressing the brake pad is adjusted by operating the brake mechanism based on the brake force required from the ECU. Generally, the brake mechanism operates by controlling the brake hydraulic pressure with a hydraulic circuit, but in recent years, the purpose is to control the braking force more precisely, and a motor is mounted on the brake mechanism, and the brake pad is used. There is also a so-called electric control type brake control device that adjusts the force generated by the motor with a motor.

  In addition to the above-described brake control device, there is also a vehicle including a regenerative brake control device that generates a braking force by controlling the amount of regeneration of a vehicle drive motor as a system for controlling the braking force.

  Patent documents 1 and patent documents 2 are known about a method of starting operation from a stop in vehicles provided with such a system.

JP, 2000-324619, A JP 2002-39237 A

  According to Patent Document 1, when the driver releases the brake pedal while the vehicle is stopped, the driving force of the vehicle and the braking force of the wheel brake are simultaneously controlled according to the depression amount of the brake pedal to start the vehicle. It is.

  According to the control method of Patent Document 1, when the brake pedal is released, the output torque of the motor is gradually increased, the brake hydraulic pressure is gradually decreased, and the brake pad is released. At this time, when the rotational force of the wheel due to the output torque of the motor becomes larger than the frictional force of the wheel brake, the vehicle gradually creeps off.

  In such a start operation method, when stick-slip occurs at the start operation, there is a problem that the rotation of the vehicle drive motor minutely fluctuates. Stick-slip is a phenomenon in which the friction surfaces of the disk rotor and the brake pad repeat adhesion and sliding, and occurs especially near the balance point between the rotational force of the wheel by the output torque of the motor and the frictional force by the brake. The variation of the frictional force between the disc rotor and the brake pad, which occurs when the stick-slip occurs, relates to the motor for driving the vehicle through the reduction gear. Therefore, when only the output torque of the motor is controlled as in the known example, the rotation of the motor may slightly fluctuate. As a result, when the vehicle performs a start operation, the driver is given a sense of drag.

  Although the above describes the stick-slip phenomenon at the time of start operation, the same problem occurs at the time of stop operation. When the rotational force of the wheel due to the output torque of the motor is in the process of decreasing at the time of stop operation and the frictional force by the brake is in the process of increasing, the stick-slip phenomenon occurs near the balance point of both.

  Although the brake mechanism which suppresses a stick-slip is proposed by patent document 2 with respect to such a subject, another subject that complication and enlargement of a mechanical mechanism arise arises.

  Therefore, an object of the present invention is to provide a control apparatus for a vehicle and a control method of a vehicle capable of suppressing the influence of the stick-slip by control without changing the mechanical mechanism.

From the above, in the present invention, “the target driving force setting means for setting the driving force of the vehicle, the torque control means for controlling the torque output by the motor according to the output of the target driving force setting means, and the torque control means Current control device for controlling the drive current of the motor according to the output of the motor, the motor for driving the vehicle, the target braking force setting means for setting the braking force of the vehicle, and the vehicle according to the output of the target braking force setting means A control device for a vehicle comprising a brake control device for braking.
At the time of start operation or stop operation of the vehicle, when one of the driving force and the braking force decreases and the other increases, it detects the state where the braking force and the driving force are balanced, and determines the rotation amount control amount. And a control unit for providing a rotation amount control amount determined by the rotation amount control unit to the current control unit.

  Furthermore, in the present invention, “a method of controlling a vehicle driven by a torque-controlled motor, wherein one of the driving force and the braking force is decreased and the other is increased, at the time of start operation or stop operation of the vehicle. A control method of the vehicle is characterized in that a rotation amount control amount is determined by detecting a state in which the braking force and the driving force are balanced, and the rotation amount control of the motor is performed.

  According to the vehicle control device of the present invention, the influence of the stick-slip can be suppressed by control without changing the mechanical mechanism, and the vehicle can be stably traveled.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the structural example of the vehicle to which this invention is applied, and a control system. The time chart which shows the vehicle information at the time of start operation from a stop by Example 1. FIG. FIG. 2 is a control block diagram for realizing the control method according to the first embodiment. FIG. 6 is a control flow diagram for realizing the control method according to the first embodiment. FIG. 7 is a control block diagram of a vehicle control device according to a second embodiment. FIG. 10 is a control flow diagram for realizing a control method according to a third embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a configuration example of a vehicle and a control system to which the present invention is applied.

  The vehicle shown in FIG. 1 includes a wheel 1, a motor 2 for driving the vehicle, a brake mechanism 3 of the wheel 1, a storage device (not shown) for storing, monitoring and controlling electric power supplied to an electric system, an ECU 4, a motor An output shaft 5 for transmitting the output torque of 2 to the wheel 1, a gear mechanism 6 for reducing the speed between the output shaft 5 and the motor 2, an inverter 7 for controlling the current flowing to the motor 2, a brake control device 8 for controlling the braking force , And a sensor group 9. In the present embodiment, one ECU is used, but the ECU may be divided into a plurality of parts, such as a motor control ECU and a brake control ECU.

  It is as follows if it adds further about each above-mentioned apparatus carried in vehicles. First, although the brake mechanism 3 of the first embodiment is a hydraulic control type brake mechanism, a motor is mounted on the brake mechanism 3 and the force generated by the brake pad is controlled by the brake control device 8 controlling the motor. It may be a so-called motor-controlled brake control device that adjusts

  The motor 2 is an AC motor of a brushless structure, and is a permanent magnet type motor.

  The sensor group 9 includes an accelerator pedal stroke sensor 10, a brake pedal stroke sensor 11, a wheel speed sensor 12, a gradient sensor 13, and a brake force detection sensor 14. A signal representing a detection result of each sensor is input to the ECU 4 Ru.

  The accelerator pedal stroke sensor 10 detects the depression amount of the accelerator pedal. The brake pedal stroke sensor 11 detects the amount of depression of the brake pedal. The wheel speed sensor 12 detects the rotational speed of the wheel. In the first embodiment, the rotational speed of the front wheel is detected, but the rotational speed of the rear wheel (not shown) may be used. Alternatively, the rotational speeds of the front and rear wheels may be detected. The slope sensor 13 detects the amount of slope of the road surface. The brake force detection sensor 14 is mounted on an oil pressure input portion of a master cylinder (not shown) of the brake mechanism 3 and measures the brake oil pressure.

  In the first embodiment, the brake force detection sensor 14 is a hydraulic pressure sensor that measures the brake hydraulic pressure. However, the present invention is not limited to this, and the brake force detection sensor 14 may be configured to use a brake force detection method according to the configuration of the brake control device.

  The ECU 4 is composed of a microcomputer and an IC group that processes input and output (not shown), and the process of control according to the present invention is that the program stored in the memory of the ECU 4 repeatedly operates in a fixed cycle. Is realized by

  Based on the signal output from the sensor group 9 described above, the map stored in the memory of the ECU 4, and the program, the ECU 4 sets the target driving force and braking force of the vehicle such that the vehicle is in a desired driving state. decide.

  In the first embodiment, the driving force and the braking force to be targeted for traveling are determined from the sensor information and the memory information, but a processor equipped with artificial intelligence AI (Artificial Intelligence), for example, a central processing unit, It may be determined by a computer unit provided with a storage device, a computer program, an input / output unit and the like.

  The ECU 4 calculates an output torque required of the motor 2 based on the determined target driving force and target braking force, and outputs a power element drive signal 15 serving as the required output torque to the inverter 7. Also, based on the determined target braking force, the required brake hydraulic pressure is calculated, and a drive signal 18 that becomes the required brake hydraulic pressure is output to the brake control device 8.

  The inverter 7 has a configuration (not shown) in which a power element IGBT (insulated gate bipolar transistor) is combined (not shown), and the IGBT is turned on and off by the power element drive signal 15 output from the ECU 4 The current is supplied to the motor 2 to control the output torque. Further, the inverter 7 is provided with a circuit (not shown) for detecting the value of the current flowing through the motor 2, calculates the output torque value generated by the motor 2 from the detected current value, and represents the output torque to the ECU 4. The signal 16 is output.

  In the first embodiment, the power element drive signal 15 is a signal from the switch output of the microcomputer, and the signal 16 representing the output torque is a signal from CAN communication. However, the inverter 7 includes a microcomputer for generating the power element drive signal. Alternatively, CAN communication may be used between the ECU 4 and the inverter 7.

  The motor 2 includes a resolver (not shown) that detects the amount of rotation of the motor, and outputs a signal 17 representing the detected amount of rotation to the ECU 4. In the first embodiment, the signal 17 representing the rotation amount is configured to use high-speed serial communication, but it is not limited thereto.

  The gear mechanism 6 decelerates between the output shaft 5 and the motor 2 to amplify the output torque of the motor.

  The brake control device 8 comprises a brake force detection sensor 14, a solenoid valve for hydraulic pressure and a solenoid current control circuit (not shown), and drives the solenoid valve based on the drive signal output from the ECU 4 to control the brake hydraulic pressure. Do.

The brake mechanism 3 is composed of a disc rotor, brake pads, and a hydraulic mechanism (not shown), and presses a brake pad fixed to the vehicle body against a disc rotor provided on the wheel 1 to generate a frictional force. The force pressing the brake pad is adjusted by controlling the braking force by the brake control device 8 based on the drive signal 18 output from the ECU 4.
Although the control device for the braking force according to the first embodiment is configured of the control device 8 and the brake mechanism 3, it is not limited thereto, and a regenerative brake control device that controls the amount of regeneration of the motor and generates the braking force is also used. It is good also as composition included.

  FIG. 2 is a time chart showing vehicle information at the time of start operation from a stop according to the first embodiment of the present invention. First, the outline of the invention will be described using this time chart diagram. In the time chart of FIG. 2, the horizontal axis represents each time at the time of the start operation from the stop, and the followings are described in (A) to (H) on the vertical axis side.

  The top row (A) shows the amount of depression of the brake pedal. (B) shows the driving force (DF: solid line) required for the vehicle determined by the ECU 4 and the braking force (BF: dotted line). (C) shows the brake hydraulic pressure controlled by the hydraulic control device 8. (D) shows the output torque of the motor 2 controlled by the inverter 7. (E) shows the target rotation amount of the motor 2 for driving the vehicle. (F) shows the vehicle speed. (G) shows a scene where stick-slip easily occurs. (H) shows the control state of the motor 2.

  As the state of control of motor 2 shown in (H), the state of torque control before time t3 and after time t4 is the output torque of motor 2 based on the driving force required for the vehicle determined by ECU 4. It shows the state of controlling only. Also, in the state of torque and rotation amount control between time t3 and t4, the rotation amount correction value for suppressing the rotational fluctuation of the motor not intended for the vehicle control with respect to the output torque of the motor 2 in the torque control state. , Indicates that control to add is in operation.

  Although the details will be described later, the embodiment 1 of the present invention basically provides a period during which the torque / rotation amount control is performed at the time of the start operation from the stop. Normally, vehicle control is performed by torque control, but at the time of start operation from a stop, control is performed as torque / rotation amount control taking in a viewpoint of rotation amount control. In the second embodiment, only the rotation amount control is applied instead of the torque / rotation amount control at the time of the start operation from the stop. Further, the third embodiment is applied to the stop operation as the event at the start operation from the stop also occurs at the stop operation.

  In addition, in order to control taking in the viewpoint of rotation amount control, it is necessary to determine the application time and the application amount, and this point is shown as a target rotation amount of the motor 2 of (E). The target rotation amount of the motor 2 is the rotation amount of the motor intended for vehicle control, and is used to calculate the rotation amount correction value in the state of the torque / rotation amount control described above. The method of calculation will be described in the next section.

  The operation in the time chart of FIG. 2 will be described in order below.

  Before time t1, the vehicle is stopped by stepping on the brake. Therefore, the vehicle speed shown in (F) is zero. Further, at this time, the braking force BF shown in (B) is set to a magnitude necessary for stopping the vehicle, and the brake hydraulic pressure shown in (C) is controlled to a pressure that generates the braking force BF. The driving force DF is set near the zero point, and the motor output torque shown in (D) is controlled near the zero point. At the time of the vehicle stop operation, since the rotation of the wheel is stationary, the occurrence area of the stick-slip shown in (G) is an area where the stick-slip is less likely to occur. Further, the control state of the motor 2 shown in (H) is a torque control state.

  When the driver slowly releases the brake pedal (A) at time t1, the braking force BF starts to decrease and the brake hydraulic pressure (C) gradually decreases.

  At time t2, when the depression amount of the brake pedal (A) further decreases, the braking force BF and the brake hydraulic pressure (C) decrease further, and preparation for start is started. At this time, the driving force DF starts to rise, and the output torque (D) of the motor starts to increase. Between time t2 and time t3, the increase of the driving force DF and the decrease of the braking force BF continue simultaneously.

  At time t3, the driving force DF becomes larger than the braking force BF. At this time, since the rotational force of the wheel by the output torque (D) of the motor becomes larger than the frictional force of the wheel brake, the vehicle gradually creeps.

  However, at this time, stick-slip may occur. As described above, stick-slip tends to occur near the balance point between the rotational force of the wheel due to the output torque (D) of the motor and the frictional force due to the brake when the wheel starts to rotate. The fluctuation of the frictional force between the disc rotor and the brake pad when the stick-slip occurs is applied to the motor 2 for driving the vehicle through the reduction gear. Therefore, when the torque control state is continued also after time t3, the rotation of the motor slightly fluctuates, which causes the deterioration of the drivability.

  Therefore, in the present invention, when the driving force DF becomes larger than the braking force BF after the time t3, it is determined that the wheel starts to rotate, and the output of the motor 2 controlled in the state of torque control Control was performed to add a correction amount that suppresses the fluctuation of the rotation amount to the torque.

  As shown in (G), the control state of the motor between time t3 and time t4 is the state of torque and rotation amount control, and as described above, the rotation amount correction value is added to the output torque of the motor 2 Be done. The rotation amount correction value is calculated based on the target rotation amount of the motor 2 described in (E) and the actual rotation amount detected by the rotation amount detection means, and the motor necessary for the actual rotation amount to be the target rotation amount Output required torque.

  At time t4, the depression amount of the brake pedal is zero, and the vehicle is creeping with only the driving force DF. At this time, since the vehicle speed is several km / h and exceeds the vehicle speed region where stick-slip is likely to occur, the torque control state is restored.

  After time t4, the output torque of the motor is controlled based on the target driving force, as in a normal vehicle. That is, it travels in a torque control state.

  In the first embodiment, the start operation from the stop is described. However, the scene to which the present invention is applied is not limited thereto, and the start operation when the accelerator pedal is depressed after the stop is in progress. You may apply at the time of deceleration.

  Furthermore, in the first embodiment, the start operation on a flat ground is described, but the scene to which the present invention is applied is not limited thereto, and may be applied to the start operation on an uphill or downhill.

  FIG. 3 is a control block diagram for realizing the control method according to the first embodiment of the present invention.

  In the ECU shown in the configuration of FIG. 3, the feature of the present invention is that a rotation amount control unit 100 shown by 100 is added. Therefore, the conventional ECU configuration other than the rotation amount control unit 100 will be described first.

  The conventional ECU configuration includes target driving force setting means 301, torque control means 303, and drive signal generating means 307 on the driving force side, and controls the inverter 313 to drive the vehicle. Further, the conventional ECU configuration includes target braking force setting means 302 and target braking force calculation means 312 on the braking force side, and controls the brake control device 314 to brake the vehicle.

  As is apparent from this configuration, in the conventional ECU, torque control is performed to obtain the driving force, but in the present invention, the viewpoint of rotation amount control is adopted to cope with the stick-slip phenomenon. The rotation amount control unit 100 determines a condition, a period, a size to be given, and the like in which the rotation amount control should be performed. In the first embodiment, this rotation amount control is used in combination with the torque control to perform torque / rotation amount control.

  Hereinafter, the ECUs of FIG. 3 will be sequentially described.

  First, the target driving force setting means 301 determines the target driving force of the vehicle based on the information from the sensor group 9 of FIG. 1 (not shown). For example, the driver's vehicle request is determined from the vehicle speed, the accelerator opening degree, and the brake pedal stroke sensor, and the driving force is determined according to the purpose.

  The target braking force setting means 302 determines the target braking force of the vehicle (not shown) based on the information from the sensor group 9 of FIG. 1 as in the case of the target driving force setting means 301. The target driving force and the target braking force may be determined by a computer unit equipped with artificial intelligence.

  The torque control means 303 calculates the output torque required of the motor 2 based on the target driving force set by the target driving force determining means 301. For example, the output torque required for the motor is calculated by multiplying the reduction ratio of the gear mechanism 6 of FIG. 1 and the target driving force.

  The rotation amount control unit 304 additionally installed according to the present invention further includes a target rotation setting unit 311. In the target rotation setting unit 311, the target driving force set by the target driving force setting unit 301, and the target control From the target braking force set by the power setting means 302 and the information of the vehicle information 310, a target rotation amount to be a control target of the motor is calculated and set as a target value.

  Below, an example of the calculation method of target rotation amount is demonstrated.

The vehicle information 310 includes the slope amount of the road surface obtained from the sensor group 9 of FIG. 1 and the actual rotation amount information of the motor obtained from the signal 17 of FIG. It also includes physical specification information such as wheel radius and vehicle weight. Here, the target driving force is DF [N], the target braking force is BF [N], the wheel radius is r [m], the reduction ratio is R, the vehicle weight is M [kg], the gravitational acceleration is G [N], Assuming that the gradient amount of the road surface is θ [rad] and the target rotation amount θ sp [deg] of the motor, the rotational speed Nout [deg / s] of the wheel is expressed by the equation (1).
[Equation 1]
Nout = {360 / (2πrM)} * ∫ (DF−BF−MG sin θ) dt (1)
At this time, the target rotation amount θsp [deg] of the motor is expressed by equation (2).
[Equation 2]
θsp = R * ∫ (Nout) dt (2)
In the first embodiment, the method of calculating the driving force acting on the vehicle itself regards the force acting on the vehicle by the gradient of the road surface as the braking force and calculates it as MGsinθ, and subtracts MGsinθ from the driving force DF on flat ground However, the present invention is not limited to this, and when determining the driving force DF and the braking force BF of the vehicle, it may be determined in advance in consideration of the gradient amount θ.

  In addition, the target rotation amount θsp [deg] of the motor in the first embodiment may be the rotation speed ωsp [deg / s] and [rad / s].

  The rotation amount control unit 304 performs feedback control of the rotation amount based on the target rotation amount θsp calculated by the above-described target rotation amount setting unit 311 and the actual value of the rotation amount detected by the resolver. A rotation amount correction value is calculated to suppress rotational fluctuation of the motor.

  The addition determination unit 305 further includes a comparison unit 305a that compares the magnitudes of the target driving force and the target braking force. In the comparison unit 305a, the value of the difference between the target driving force and the target braking force is larger than the specified value. It is detected whether or not it continues for a fixed time, and when it is detected that it continues, it is determined to be added. As a result of this determination, the time at which (target driving force-target braking force)> specified value is obtained is time t3 in FIG. When it is determined that the addition is performed by the comparison unit 305a, the output processing unit 305b outputs the rotation amount correction value calculated by the rotation amount control unit 304.

  Also, if the vehicle speed value 308 is above the specified value, that is, if the vehicle speed exceeds the low vehicle speed area where stick-slip is likely to occur, or if the brake pedal depression amount 309 is above the specified value, that is, the driver When it is stepped on, it is determined that the addition is not performed, and zero is output from the output processing 305b.

  In the comparison means 305 a of the first embodiment, it is determined that the addition is performed when the difference between the target driving force and the target braking force is larger than the specified value and continues for a certain period of time. The method is not limited to that, and the determination may be made based on values from sensor information, estimated values, and the like of the vehicle.

  In short, it is sufficient that the time t3 can be determined in FIG. 2B. For example, the value of the difference between the target driving force increasing at the start operation and the target braking force decreasing at the start operation exceeds the specified value. It is sufficient that the rotation amount correction value is given when the period of the driving force> the target braking force continues for a predetermined time or more.

  The addition means 306 adds the zero or the rotation amount correction value output from the addition determination means 305 to the output torque calculated by the torque control means 303. The added value is output to the drive signal generation means 307 as the required torque value of the motor.

  The drive signal generation unit 307 generates a power element drive signal to be output from the ECU to the inverter 313 such that the output torque generated by the motor becomes the required torque value output from the addition unit 306.

  The target braking force calculating means 312 calculates a target braking force to be generated by the brake device based on the target braking force set by the target braking force determining means 302. Also, a drive signal is output to the brake control device 314 so as to achieve the target brake force.

  In the first embodiment, although one ECU is used, a plurality of ECUs may be provided like the motor control ECU and the brake control ECU, and the control blocks 301 to 312 shown in FIG. The corresponding function may be configured across multiple ECUs.

  FIG. 4 shows the control flow of the present invention described above. Note that this control flow is repeatedly executed at fixed time intervals in accordance with a control cycle in a computer that constitutes the ECU.

  In the first processing step S401 in the control flow of FIG. 4, it is determined whether the driver steps on the brake pedal. In the first embodiment, when the brake pedal stroke amount is equal to or more than the specified value, it is determined that the brake is ON. On the other hand, when it is below the prescribed value, it is determined that the brake is OFF. Different values are set to the prescribed values of the ON and OFF states of the brake, which are determined by hysteresis.

  If the brake is ON, the timer for addition determination is cleared in processing step S408, and the motor continues torque control. If the brake is off, it is determined in process step S402 that the brake pedal has been released.

  In processing step S402, the target driving force and the target braking force are compared by the comparison means 305, and the difference between the target driving force and the target braking force is equal to or greater than the specified value ((target driving force-target braking force)> specified value) In step S403, the timer for addition determination is incremented. If the value is smaller than the specified value, the timer for addition determination is cleared in processing step S408, and the motor performs only torque control.

In processing step S404, it is determined whether the addition determination timer is greater than or equal to a specified value.
Therefore, in processing step S402 to processing step S404, it is determined whether or not the target driving force is larger than the target braking force continuously for the prescribed time or more, and if it is the prescribed time or more, the process proceeds to processing step S405. The calculation of the rotation amount correction value for suppressing the rotation fluctuation of the motor is started. If it is less than the specified time, it is not processed.

  In the processing of the processing step S402 to the processing step S404 in the first embodiment, the state in which the difference between the target driving force and the target braking force is equal to or more than the specified value continues for a fixed period of time. It is determined to start the calculation. However, the embodiment of the present invention is not limited to the above method, and a scene where the rotation of the vehicle drive motor becomes unstable during traveling may be detected and determined from a sensor or the like. For example, each sensor detects each of the vehicle speed, steering angle, vehicle acceleration, and current value of the drive motor, and it is determined that calculation of the rotation amount correction value is started when each value satisfies a predetermined condition. You may

  At processing step S405, a rotation amount correction value is calculated based on the target rotation amount of the motor calculated by the target rotation amount setting means 311 described above and the actual value of the motor rotation amount detected by the resolver. The calculated rotation amount correction value is added to the output torque calculated by the torque control means 303, and the rotation amount of the motor is controlled.

  In processing step S406, it is determined whether the vehicle speed exceeds a low vehicle speed area where stick-slip is likely to occur. If the vehicle speed is equal to or higher than the specified value, the process proceeds to step S407 and the torque control state is set.

  In processing step S407, only the torque of the motor is controlled based on the driving force without adding the rotation amount correction value.

  By configuring as described above, it is possible to control the amount of rotation of the motor when starting to start, so that the influence of the friction fluctuation due to the stick-slip is suppressed.

  The first embodiment of the present invention may be as in the second embodiment described below.

  The vehicle control device according to the second embodiment will be described below with reference to FIGS. 3 and 4.

  The addition means 306 of FIG. 3 according to the first embodiment described above adds the rotation amount correction value to the torque control amount in order to suppress the fluctuation of the rotation amount of the motor. On the other hand, in the second embodiment, the control itself is switched from torque control to rotation amount control, and control is performed using only the rotation amount correction value.

  FIG. 5 is a control block diagram of a vehicle control device according to a second embodiment. A difference from the first embodiment is that the addition means 306 of FIG. 3 according to the first embodiment is the control switching means 506, and the other points are the same.

  Therefore, in the second embodiment, the motor for driving the vehicle, the current control device for controlling the driving current of the motor, the target driving force setting means for setting the driving force of the vehicle, and the target braking force for setting the braking force of the vehicle Setting means, means for detecting the torque output by the motor, means for detecting the rotation amount of the motor, torque control means for controlling the torque output by the motor, rotation amount control means for controlling the rotation amount of the motor And the switching means for switching between the rotation amount control means and the torque control means, the target driving force set by the target driving force setting means, and the target control. The apparatus further comprises switching determination means for determining whether or not to switch the switching means based on the target braking force set by the power setting means, and the switching determination means determines that the amount of rotation of the motor is to be controlled. Stage by switching the rotation amount control means from the torque control means so that the amount of rotation of the motor becomes a desired amount of rotation, and controls the current control device.

  With the above-described configuration, the same effect as that of the first embodiment can be obtained. In short, according to the present invention described in the first and second embodiments, in the process of starting the vehicle, the value of the difference between the target driving force increasing at the start operation and the target braking force decreasing at the start operation exceeds the specified value. The rotation amount control is executed when the period of the driving force> the target braking force continues for a predetermined time or more, and in the second embodiment, the total amount of rotation amount is switched by switching between torque control and rotation amount control. There is only a difference in implementation method, such as whether to use control or torque / rotation amount control (partial rotation amount control) by using in combination with torque control as in the first embodiment.

  In the first embodiment and the second embodiment, the stick-slip phenomenon at the start operation of the vehicle is dealt with, but the same problem also occurs at the stop operation. When the rotational force of the wheel due to the output torque of the motor is in the process of decreasing at the time of stop operation and the frictional force by the brake is in the process of increasing, the stick-slip phenomenon occurs near the balance point of both.

  Therefore, it is preferable to take measures against the stick-slip phenomenon at the time of stop operation as well as the first embodiment and the second embodiment.

  In this case, the control flow of FIG. 4 may be changed for the stop operation while leaving the configurations of the ECUs of FIGS. 3 and 5 as they are. For example, the control flow of FIG. 6 can be made.

  The control flow of FIG. 6 differs from the control flow of FIG. 3 in the following two points. The first point is to reverse the processing of processing step S401A to the processing of processing step S401 of FIG. 3. If the brake is OFF, the timer for addition determination is cleared in processing step S408, and the motor is Continues torque control. If the brake is ON, it is determined in processing step S402 that the brake pedal has been strengthened.

  The second point is to reverse the process of the process step S402A from the process of the process step S402 of FIG. 3 and to determine that braking force-driving force> specified value.

  In addition, when taking measures against the stick-slip phenomenon at the time of start operation and at the time of stop operation, the judgments of FIG. 4 and FIG. 6 are effective only when both the braking force and the driving force are generated. Good. For example, in the case of judging braking force-driving force> specified value, the flow is such that the rotation amount control is instructed even when the driving force is zero, but such a case should naturally be excluded.

  According to the present invention through the above-described first embodiment, second embodiment and third embodiment, when one of the braking force and the driving force decreases while the other increases during the start operation or the stop operation of the vehicle in which the torque control is performed. In addition, the rotation amount control is performed by detecting a state in which the braking force and the driving force are balanced. Methods of rotation amount control include total amount rotation amount control and partial rotation amount control.

  According to the conventional method, the output torque of the vehicle drive motor is controlled based on the driving force at the time of the start operation. Therefore, even if the rotation of the motor fluctuates due to the change of the frictional force around the wheel, the control is not performed to correct it. In this respect, according to the present invention, since the viewpoint of the rotation amount control is taken, it is possible to cope with the change of the frictional force around the wheel.

  With such a control device for a vehicle, in a situation where stick-slip easily occurs, a target rotation amount of a vehicle drive motor intended for vehicle control is determined based on the target driving force and the target braking force of the vehicle. It becomes possible to control the actual rotation of the motor so as to achieve the target rotation amount. As a result, minute fluctuations in the rotation of the vehicle drive motor can be suppressed, and the vehicle can be stably traveled.

  As mentioned above, although the embodiment of the present invention has been described in detail using the drawings, the specific configuration is not limited to this embodiment, and there are design changes and the like within the scope of the present invention. Also, they are included in the present invention.

1: Wheel 2: Motor 3: Brake mechanism 4: ECU
5: output shaft 6: gear mechanism 7: inverter 8: brake control device 9: sensor group 10: accelerator pedal stroke sensor 11: brake pedal stroke sensor 12: wheel speed sensor 13: gradient sensor 14: brake force detection sensor 15: power Element drive signal 16: Motor output torque 17: Motor rotation amount signal 18: Drive signal

Claims (10)

Target driving force setting means for setting the driving force of the vehicle, torque control means for controlling the torque output by the motor according to the output of the target driving force setting means, and the motor of the motor according to the output of the torque control means A current control device for controlling a drive current, the motor for driving the vehicle, a target braking force setting means for setting a braking force of the vehicle, and a brake for braking the vehicle according to the output of the target braking force setting means A control device for a vehicle, comprising: a control device;
At the time of start operation or stop operation of the vehicle, when one of the driving force and the braking force decreases and the other increases, a state in which the braking force and the driving force are balanced is detected to determine the rotation amount control amount A control device for a vehicle, comprising: control means for giving a rotation amount control amount determined by the rotation amount control means to the current control device. The vehicle control device according to claim 1, wherein
For a vehicle characterized in that the current control device controls the drive current of the motor according to the output of the torque control means and the output of the rotation amount control means when detecting a state in which the braking force and the driving force are balanced. Control device. The vehicle control device according to claim 1, wherein
When detecting a state in which the braking force and the driving force are balanced, the current control device controls the driving current of the motor according to the output of the rotation amount control means instead of the output of the torque control means. Control device for vehicles. A vehicle control device according to any one of claims 1 to 3, wherein
At the time of start operation of the vehicle, when the braking force is reduced and the driving force is increased, the state where the braking force and the driving force are balanced is detected as (driving force-braking force> specified value) continues for a predetermined time. A control device for a vehicle, comprising: The vehicle control device according to any one of claims 1 to 4, wherein
At the time of the stop operation of the vehicle, when the braking force increases and the driving force decreases, the state where the braking force and the driving force are balanced is detected as (braking force-driving force> specified value) continues for a predetermined time. A control device for a vehicle, comprising: A control device for a vehicle according to any one of claims 1 to 5, wherein
The control device for a vehicle according to claim 1, wherein the driving force is a target driving force set by the target driving force setting means, and the braking force is a target braking force set by the target braking force setting means. The vehicle control device according to claim 6, wherein
The rotation amount control means further includes target rotation setting means.
The target rotation setting means sets a target rotation amount or a target rotation speed to be a control target of the motor from the target driving force and the target braking force.
The control device for a vehicle, wherein the rotation amount control means calculates the rotation amount control amount such that the rotation amount or rotation speed of the motor becomes the target rotation amount or the target rotation speed. . The vehicle control device according to claim 6 or 7, wherein
The target driving force setting means and the target braking force setting means are means for measuring the current amount of the driving current of the motor, means for detecting the rotation amount of the motor, and means for detecting the slope amount of the road surface. And a means for detecting an accelerator pedal opening degree, a means for detecting an amount of depression of a brake pedal, and a means for detecting the speed of the vehicle, wherein the target driving force and the target braking force are determined. Control device for vehicles. The vehicle control device according to any one of claims 6 to 8, wherein
The system further comprises a braking force generator that generates a braking force that results in the target braking force,
The control device for a vehicle, wherein the braking force generating device comprises a motor for generating a braking force and a motor control device. A control method of a vehicle driven by a torque controlled motor, comprising:
At the time of start operation or stop operation of the vehicle, when one of the driving force and the braking force decreases and the other increases, a state in which the braking force and the driving force are balanced is detected to determine a rotation amount control amount. A control method of a vehicle, comprising: controlling a rotation amount.

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