JP2016123172A - Vehicle drive force control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle drive force control device capable of suppressing the generation of acceleration feel different from a driver's intention due to a drive force difference control accompanying steering.SOLUTION: A vehicle controller 11 as a vehicle drive force control device for controlling electric motors 3RL, 3RR to be driven on the basis of a sensor group 100, comprises: a front-rear-direction drive-torque control unit (a one-wheel-motor-torque arithmetic unit 102, a power-performance control unit 109) setting an acceleration one-wheel torque to each of right and left rear wheels 1RL, 1RR in response to a demand drive torque by the driver; and a right/left-wheel-drive-torque-difference setting unit (a target-yaw-rate arithmetic unit 103, a vehicle-moment arithmetic unit 104, a right/left-motor-torque-difference arithmetic unit 105) setting a right/left-wheel motor torque difference ΔtTm as a right/left drive torque difference for controlling a vehicle state to each of the right and left rear wheels 1RL, 1RR in response to the vehicle state, and is further provided with a power-performance-limitation-amount arithmetic unit 108 setting a limitation amount for limiting a motor maximum torque in response to a steering angle θ.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle driving force control device that executes control for giving a driving force difference to left and right driving wheels in a vehicle including an electric motor that can independently apply driving force to left and right driving wheels of the vehicle. It is about.

2. Description of the Related Art Conventionally, there is known a vehicle driving force control device that includes an electric motor that drives left and right driving wheels and controls a yaw rate behavior of the vehicle by setting a driving force difference between the left and right driving wheels by motor torque control ( For example, see Patent Document 1).
In addition, in this conventional technique, when the driving force difference control cannot satisfy the required driving torque in the front-rear direction and the required driving torque based on the driving force difference control at the same time, torque control that gives priority to the driving torque based on the driving force difference control is performed. Is doing.

Japanese Patent Laying-Open No. 2005-073457

  However, when the driving force difference control is executed during acceleration, if the driving torque of the driving force difference control is prioritized over the driving torque for acceleration, the driving force for acceleration cannot be secured sufficiently, and the driver's There was a risk that the intended acceleration could not be obtained.

  The present invention has been made paying attention to the above-mentioned conventional problems, and is a vehicle driving force control device capable of suppressing a feeling of acceleration different from the driver's intention due to the driving force difference control accompanying steering. The purpose is to provide.

In order to achieve the above-described object, the vehicle driving force control device of the present invention includes:
Included in a drive control device that controls the drive of the electric motor based on detection by a vehicle state detection device that detects a vehicle state including a driver's operation state. A front / rear direction drive torque control unit for setting a front / rear direction drive torque for the drive wheel, and a left / right wheel drive for independently setting a left / right drive torque difference for vehicle state control to the left and right drive wheels according to the vehicle state A vehicle driving force control device including a torque difference setting unit,
A drive force control device for a vehicle, wherein the drive control device is provided with a limit amount setting unit for setting a limit amount for limiting the maximum motor torque according to a steering angle obtained from the vehicle state detection device. .

In the vehicle driving force control device of the present invention, when the left / right driving force difference control is executed, the motor maximum torque is limited according to the steering angle.
That is, when cornering, cornering resistance is generated, resulting in a decrease in acceleration performance. Therefore, when turning without causing a sense of incongruity even when the acceleration performance is reduced in this way, by limiting the motor maximum torque according to the steering angle, it is possible to limit the vehicle longitudinal driving torque without a sense of incongruity. Then, by executing the left / right driving force difference control after limiting the motor maximum torque, the left / right driving force difference control can be executed within a range not exceeding the motor maximum torque.
Therefore, it is possible to execute the left / right driving force difference control while limiting the maximum motor torque while suppressing deterioration in acceleration performance and the resulting uncomfortable feeling.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic system diagram which shows the whole control system regarding the drive system of the electric vehicle provided with the drive force control apparatus of Embodiment 1 of this invention. FIG. 3 is a functional block diagram illustrating a configuration for executing steering response DYC control in the driving force control apparatus of the first embodiment. 6 is a flowchart showing a flow of processing of steering response DYC control in the driving force control apparatus of the first embodiment. FIG. 3 is a motor torque characteristic diagram showing a relationship between a motor maximum torque and an in-phase limit torque according to a vehicle speed and an accelerator opening degree in the driving force control apparatus of the first embodiment. FIG. 3 is a characteristic diagram of a limit amount at the time of turning in the driving force control apparatus of the first embodiment. 3 is a lateral acceleration calculation map used for calculating lateral acceleration from a vehicle speed and a steering angle in the driving force control apparatus of the first embodiment. 3 is a time chart showing an operation example during acceleration turning in the driving force control apparatus of the first embodiment. FIG. 3 is a functional block diagram illustrating a configuration for performing steady lateral acceleration DYC control in the driving force control apparatus of the first embodiment. 6 is a flowchart showing a flow of processing of steady lateral acceleration DYC control in the driving force control apparatus of the first embodiment. FIG. 3 is a functional block diagram illustrating a configuration for performing cross wind DYC control in the driving force control apparatus of the first embodiment. 3 is a flowchart showing a flow of cross wind DYC control processing in the driving force control apparatus of the first embodiment. FIG. 3 is a functional block diagram illustrating a configuration for executing acceleration / deceleration DYC control in the driving force control apparatus according to the first embodiment. 4 is a flowchart showing a flow of acceleration / deceleration DYC control processing in the driving force control apparatus of the first embodiment. FIG. 6 is a response characteristic diagram showing a relationship between responsiveness of each DYC control and lateral responsiveness obtained from the vehicle speed and the steering angle in the driving force control apparatus of the first embodiment. FIG. 4 is a limit amount characteristic diagram showing a relationship among responsiveness of each DYC control, responsiveness of lateral acceleration, and a limit amount in the driving force control apparatus of the first embodiment. FIG. 6 is a functional block diagram illustrating a main part of a modification of the first embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<Configuration of Embodiment 1>
FIG. 1 is a schematic system diagram showing an overall control system related to a drive system of an electric vehicle equipped with a vehicle driving force control apparatus according to Embodiment 1 of the present invention.

This electric vehicle includes left and right front wheels 1FL and 1FR and left and right rear wheels 1RL and 1RR. The left and right rear wheels 1RL and 1RR are driven by electric motors (in-wheel motors IWN) 3RL and 3RR incorporated in the respective wheels. It is possible to run.
Further, steering is possible by steering the steering wheel 13 to steer the left and right front wheels 1FL, 1FR.
The electric motors 3RL and 3RR are motor / generators that can also function as generators, and the left and right rear wheels 1RL and 1RR can be regeneratively braked.

  The electric vehicle in FIG. 1 includes a vehicle controller 11 that performs drive control and regenerative control of the electric motors 3RL and 3RR. Further, the vehicle controller 11 controls the behavior of the vehicle by controlling the driving force difference between the left and right rear wheels 1RL and 1RR that are left and right driving wheels via the electric motors 3RL and 3RR.

A detection signal from the sensor group 100 is input to the vehicle controller 11. The sensor group 100 includes an accelerator opening sensor 112, a steering angle sensor 113, a yaw rate sensor 114, a longitudinal acceleration sensor 115, a lateral acceleration sensor 116, wheel speed sensors 117a to 117d, and a brake pedal sensor 118.
The accelerator opening sensor 112 detects an accelerator opening APO, which is an accelerator pedal depression amount (not shown).
The steering angle sensor 113 detects the steering angle θ of the steering wheel 13. Instead of the steering angle sensor 113, the turning angle of the left and right front wheels 1FL, 1FR may be detected.
The yaw rate sensor 114 detects a yaw rate φ that is a behavior around the vertical axis of the vehicle. The longitudinal acceleration sensor 115 detects the longitudinal acceleration Gx of the vehicle. The lateral acceleration sensor 116 detects the lateral acceleration Gy of the vehicle.
Wheel speed sensors 117a to 117d detect wheel speeds VwFL, VwFR, VwRL, and VwRR of each wheel 1FL, 1FR, 1RL, and 1RR.
The brake pedal sensor 118 detects the amount of depression of the brake pedal (not shown) (the amount of depression of the brake pedal BPO).

Based on the input information from the sensor group 100, the vehicle controller 11 calculates a final left wheel torque command value Tm_L and a final right wheel torque command value Tm_R corresponding to the target motor torques of the electric motors 3RL and 3RR.
The calculated torque command values Tm_L and Tm_R are output to the inverter 18, and electric power corresponding to the torque command values Tm_L and Tm_R is supplied from the inverter 18 to the electric motors 3RL and 3RR, and the target drive torque Is output from the left and right rear wheels 1RL, 1RR.

<Yaw control control>
In the first embodiment, the yaw control control for controlling the yaw rate of the vehicle is executed by independently setting the drive torques of the left and right electric motors 3RL and 3RR and giving the left and right drive torque difference.

Hereinafter, yaw control control executed by the vehicle controller 11 in the electric vehicle will be described.
As the yaw control control, steering response DYC control (Direct Yaw Control), steady lateral acceleration DYC control, acceleration / deceleration DYC control, and cross wind DYC control are executed. Each DYC control is always executed in parallel.
The steering response DYC control is a control for setting a driving force difference between the left and right motor drive wheels so as to optimize the steering response at the time of steering.
The steady lateral acceleration DYC is a control for setting a driving force difference between the left and right motor driving wheels so as to reduce a change in the yaw rate when the vehicle turns in a vehicle width direction.
The acceleration DYC control is a control for setting a driving force difference between the left and right motor driving wheels so as to reduce a yaw rate change during an acceleration / deceleration operation in which a longitudinal load movement of the vehicle occurs.
The crosswind DYC control is a control for setting a driving force difference between the left and right motor drive wheels so as to suppress disturbance caused by the crosswind.

Below, the structure which performs each DYC control, and its control flowchart are demonstrated.
(Steering response DYC control)
FIG. 2 is a functional block diagram showing a configuration for executing the steering response DYC control in the vehicle controller 11. FIG. 3 is a flowchart showing the flow of the steering response DYC control process.
In the steering response DYC control, when the vehicle is likely to become an understeer state or an oversteer state due to a steering operation by the driver, a yaw rate is generated in a direction to suppress the vehicle.

  As shown in FIG. 2, the vehicle controller 11 includes a one-wheel motor torque calculation unit 102, a target yaw rate calculation unit 103, a vehicle moment calculation unit 104, a left and right wheel motor torque difference calculation unit 105, a turning state estimation unit 106, and a motor maximum torque. A calculation unit 107, a power performance limit amount calculation unit 108, a power performance limit unit 109, and a final left and right torque command value calculation unit 110 are provided.

Note that each processing step in the flowchart of FIG. 3 corresponds to processing executed by each of the units 102 to 110 shown in FIG.
In the following, processing of each configuration shown in FIG. 2 will be described in correspondence with the flowchart of FIG.

The single-wheel motor torque calculation unit 102 reads the accelerator opening APO, the vehicle speed (vehicle speed) VSP, and the common-mode limit torque described later, and based on the preset single-wheel motor torque setting map shown in FIG. A single wheel motor torque command value tTm corresponding to the required drive torque is obtained. The single-wheel motor torque command value tTm obtained by the single-wheel motor torque calculation unit 102 corresponds to the front-rear direction drive torque according to the driver's requested drive torque, and outputs torque to the left and right rear wheels 1RL, 1RR. It is calculated as an in-phase torque component having the same direction. Then, the obtained single-wheel motor torque command value tTm is output to the power performance limiting unit 109.
The vehicle speed VSP is obtained from the wheel speeds of the left and right front wheels (driven wheel speed), for example.
Further, the one-wheel motor torque setting map in FIG. 4 shows the motor torque on the acceleration side. On the regeneration side, the motor torque is the absolute value of the motor maximum torque lower as the vehicle speed becomes higher as in FIG. It becomes the negative value of the characteristic. Then, the limit amount is set so as to suppress the limit amount on the regeneration side with respect to the acceleration side, as shown in FIG.

  Further, the common-mode limit torque is a torque obtained by giving a limit amount to the motor maximum torque according to the lateral acceleration YG obtained from the steering angle θ in the power performance limit amount calculation unit 108 described later with respect to the motor maximum torque. The value obtained in the previous control cycle is used.

  Here, the allocation of the accelerator opening APO to the vehicle speed in the one-wheel motor torque setting map shown in FIG. 4 is set according to the common mode limit torque. That is, the relationship between the accelerator opening APO and the motor torque (single-wheel motor torque command value tTm) according to the vehicle speed VSP is set so that the common-mode limiting torque can be obtained at the accelerator opening APO = 100%. For example, a characteristic corresponding to the minimum accelerator opening in the control region that responds to the accelerator opening APO is set in advance. Then, intermediate characteristics such as 20, 40, and 60% shown in the figure are equally allocated between the characteristics of the in-phase limiting torque with the accelerator opening APO = 100% and the characteristics of the minimum accelerator opening.

Returning to FIG. 2, the target yaw rate calculation unit 103 obtains the target yaw rate tφ of the vehicle from the steering angle θ and the vehicle speed VSP, and outputs the obtained target yaw rate tφ to the vehicle moment calculation unit 104 (step S103 in FIG. 3).
The target yaw rate tφ may be obtained according to the steering angle θ and the vehicle speed VSP with reference to a preset map, or may be calculated using an arithmetic expression such as the following expression (1). .
tφ = (VSP × θ) / L (1)
In equation (1), L is the wheel base of the vehicle, θ is the steering angle (or actual turning angle = θ × steering gear ratio), and VSP is the vehicle speed (vehicle speed).

The vehicle moment calculation unit 104 calculates a vehicle moment My necessary for realizing the target yaw rate tφ from the vehicle speed VSP and the target yaw rate tφ. Then, the obtained vehicle moment My is output to the left and right wheel motor torque difference calculation unit 105 (step S104 in FIG. 3).
Note that the vehicle moment My can be obtained by numerically solving a vehicle motion model that is built based on a vehicle motion equation in advance.

The left and right wheel motor torque difference calculation unit 105 calculates a left and right wheel motor torque difference ΔtTm that forms a torque difference between the left and right rear wheels 1RL and 1RR necessary to generate the vehicle moment My obtained by the vehicle moment calculation unit 104 by the following equation. Obtained by (2) (step S105 in FIG. 3).
ΔtTm = My × (1 / Lw) × (1 / i) × Rw (2)
Note that My is a vehicle moment, Lw is a tread width, i is a transmission gear ratio, and Rw is a tire moving radius.
Further, in the first embodiment, the left / right wheel motor torque difference ΔtTm is a value that forms the vehicle moment My in the counterclockwise direction (left steering direction) when the vehicle is viewed from above, and the clockwise direction ( The value that forms the vehicle moment My in the right steering direction) is calculated as negative.

  The turning state estimation unit 106 calculates the lateral acceleration YG of the vehicle from the vehicle speed VSP and the steering angle θ (step S106 in FIG. 3). The lateral acceleration YG can be obtained using, for example, a lateral acceleration calculation map shown in FIG. 6, and based on this map, the lateral acceleration YG is set to a larger value as the vehicle speed VSP and the steering angle θ are increased. The obtained lateral acceleration YG is used to obtain a value for limiting the longitudinal driving torque according to the steering angle θ.

The motor maximum torque calculation unit 107 calculates the motor maximum torque from the motor rotation speeds of the left and right wheels (step S107 in FIG. 3).
This calculation is performed based on a map (not shown). This map is set so that the maximum motor torque decreases as the motor rotation speed increases. The specifications of the electric motors 3RL and 3RR are preliminarily set. The characteristics are set based on

The power performance limit calculation unit 108 calculates the common-mode limit torque according to the lateral acceleration YG obtained by the turning state estimation unit 106 and the motor maximum torque obtained by the motor maximum torque calculation unit 107 (FIG. 3). Step S108).
In calculating the common-mode limiting torque, first, a limiting amount corresponding to the lateral acceleration YG is obtained based on the map shown in FIG. As shown in the figure, the limit amount is set differently on the acceleration side and the regeneration side, and the limit amount is set larger on the acceleration side than on the regeneration side.
Then, the power performance limit amount calculation unit 108 calculates the common mode limit torque according to the following equation (3) based on the limit amount calculated based on the map of FIG. 5 and the motor maximum torque input from the motor maximum torque calculation unit 107. calculate.
In-phase limit torque = Motor maximum torque-Limit amount (3)

Here, in-phase refers to the same direction in the front-rear direction from the left and right rear wheels 1RL, 1RR when the vehicle is accelerated or decelerated in accordance with the required drive torque (vehicle target acceleration) according to the driver's acceleration / deceleration operation. The torque that is output.
On the other hand, when the yaw control control for controlling the yaw rate of the vehicle is performed, reverse torque (reverse phase torque) is added to each of the rear wheels 1RL and 1RR. That is, for both rear wheels 1RL and 1RR, torque in the same direction as the in-phase torque is added to one side, while torque in the opposite direction to the in-phase torque is added to the other side (in-phase torque). Subtraction).

  The above-described limit amount characteristics shown in FIG. 5 are set according to the size of the cornering resistance. That is, at the time of turning, the cornering resistance is usually generated, so that the acceleration performance is lowered. Therefore, it is known for the driver that the acceleration performance is reduced to some extent when turning, and it is difficult to give a sense of incongruity. Therefore, the limit amount in FIG. 5 is set in a range in which the driver does not feel a decrease in acceleration performance more than the decrease in acceleration performance due to turning.

  Returning to FIG. 2, the power performance limiting unit 109 accelerates from the single-wheel motor torque command value tTm obtained by the single-wheel motor torque calculation unit 102 and the common-mode limit torque obtained by the power performance limit amount calculation unit 108. One-wheel torque is obtained (step S109 in FIG. 3). That is, the power performance limiting unit 109 selects (selects low) the smaller value of the one-wheel motor torque command value tTm and the common-mode limiting torque. Thereby, when the single-wheel motor torque command value tTm exceeds the common mode limit torque, the single mode motor torque command value tTm is limited to the common mode limit torque.

The final left and right torque command value calculation unit 110 calculates a final left wheel torque command value Tm_L and a final right wheel torque command value Tm_R that are final torque command values for the left and right electric motors 3RL and 3RR (step S110 in FIG. 3). .
Here, the final right wheel torque command value Tm_R is obtained by adding the left and right wheel motor torque difference ΔtTm obtained by the left and right wheel motor torque difference calculating unit 105 to the acceleration one wheel torque obtained by the power performance limiting unit 109. Ask.
On the other hand, the final left torque command value is obtained by subtracting the left and right wheel motor torque difference ΔtTm obtained by the left and right wheel motor torque difference computing unit 105 from the acceleration single wheel torque obtained by the power performance limiting unit 109.

  In this addition / subtraction, for example, when the direction of the target yaw rate tφ is the same as the steering direction, the left / right wheel motor torque difference ΔtTm is added to the turning outer wheel side with respect to the common acceleration one-wheel torque on the left and right, and the turning Subtract from the inner ring side.

In the configuration for executing the steering response DYC control described above, the one-wheel motor torque calculation unit 102 and the power performance limiting unit 109 correspond to a front-rear direction drive torque control unit that sets the front-rear direction drive torque. Further, the target yaw rate calculation unit 103, the vehicle moment calculation unit 104, and the left and right wheel motor torque difference calculation unit 105 set the left and right wheel drive torque difference setting for setting the left and right torque difference drive torque that forms the left and right drive torque difference for vehicle state control. It corresponds to the part.
The turning state estimation unit 106, the motor maximum torque calculation unit 107, the power performance limit amount calculation unit 108, and the power performance limit unit 109 correspond to a front-rear direction drive torque limit unit that limits the front-rear direction drive torque.

(Steady lateral acceleration DYC control)
Next, the steady lateral acceleration DYC control will be described based on FIGS.
FIG. 8 is a block diagram showing a configuration in which the steady lateral acceleration DYC control for generating the vehicle moment My so as to suppress the yaw rate change according to the lateral acceleration Gy generated in the vehicle in the vehicle controller 11 is executed. FIG. 9 is a flowchart showing the flow of processing for steady lateral acceleration DYC control.

  Of the configurations that execute the steady lateral acceleration DYC control, configurations that are the same as the configurations that execute the steering response DYC control described with reference to FIG. Similarly, in the acceleration DYC control and the crosswind DYC control described below, the description of the same configuration as the steering response DYC control is omitted.

  In the steady lateral acceleration DYC control, when obtaining the left and right wheel motor torque difference ΔtTm, calculation is performed so as to suppress a yaw rate change during turning traveling that causes load movement in the vehicle width direction of the vehicle. As a configuration for that purpose, a lateral acceleration yaw rate suppression target value calculation unit 200 and a vehicle moment calculation unit 204 are provided.

  The lateral acceleration yaw rate suppression target value calculation unit 200 obtains a lateral acceleration yaw rate suppression target yaw rate tφ_Gy_ΔY from the lateral acceleration Gy of the vehicle detected by the lateral acceleration sensor 116 and the target yaw rate tφ obtained by the target yaw rate calculation unit 103 ( Step S200 in FIG. 9).

  In this case, first, the vehicle width direction load movement of the vehicle is obtained from the detected lateral acceleration Gy of the vehicle. Next, the yaw rate change accompanying the vehicle width direction load movement is calculated from the vehicle width direction load movement and the target yaw rate tφ. Then, a target yaw rate tφ_Gy_ΔY for lateral acceleration yaw rate suppression necessary to suppress this as intended is determined.

  The vehicle moment calculation unit 204 calculates the vehicle moment My by adding together the yaw moment necessary for realizing the target yaw rate tφ and the yaw moment required for realizing the target yaw rate tφ_Gy_ΔY for suppressing the lateral acceleration yaw rate. (Step S204 in FIG. 9).

Therefore, the left and right wheel motor torque difference calculation unit 105 forms the torque difference between the left and right rear wheels 1RL and 1RR necessary to suppress the lateral acceleration yaw rate due to the detected lateral acceleration Gy of the vehicle based on the vehicle moment My. The wheel motor torque difference ΔtTm is calculated.
About another structure and process, it is the same as that of the structure and process which perform steering response DYC control.

(Cross wind DYC control)
Next, the cross wind DYC control will be described with reference to FIGS.
FIG. 10 is a block diagram showing a configuration for executing the cross wind DYC control for generating the vehicle moment My so as to suppress the yaw rate change due to the cross wind disturbance in the vehicle controller 11. FIG. 11 is a flowchart showing the flow of the cross wind DYC control process.

  The target yaw rate calculation unit 300 for suppressing the side wind disturbance is a deviation between the yaw rate φ detected by the yaw rate sensor 114 (see FIG. 1) and the target yaw rate tφ obtained by the target yaw rate calculation unit 103 (a disturbance due to a transient side wind). Change in yaw rate). And the target wind rate tφ_Gyw_ΔY for cross wind disturbance suppression necessary to suppress this as intended is determined (step S300 in FIG. 11).

  The vehicle yaw moment calculation unit 304 adds the yaw moment necessary for realizing the target yaw rate tφ and the yaw moment required for realizing the target yaw rate tφ_Gyw_ΔY for suppressing the side wind disturbance. Then, the vehicle moment My capable of realizing the combined target yaw rate is calculated (step S304).

  Therefore, the left and right wheel motor torque difference calculation unit 105 forms the torque difference between the left and right rear wheels 1RL and 1RR necessary to suppress the lateral wind disturbance based on the detected yaw rate φ based on the vehicle moment My. The difference ΔtTm is calculated.

(Acceleration / deceleration DYC control)
Next, acceleration / deceleration DYC control will be described with reference to FIGS.
FIG. 12 is a block diagram showing a configuration for executing acceleration / deceleration DYC control for generating the vehicle moment My so as to suppress the yaw rate change caused by the acceleration / deceleration operation in the vehicle controller 11. FIG. 13 is a flowchart showing the flow of acceleration / deceleration DYC control processing.

The acceleration / deceleration yaw rate change suppression target yaw rate calculation unit 400 first calculates the vehicle longitudinal acceleration XG from the accelerator opening APO detected by the accelerator opening sensor 112 and the brake pedal depression amount BPO detected by the brake pedal sensor 118. Note that the longitudinal acceleration Gx detected by the longitudinal acceleration sensor 115 may be used as the longitudinal acceleration.
Further, the acceleration / deceleration yaw rate change suppression target yaw rate calculation unit 400 obtains the longitudinal load movement of the vehicle from the longitudinal acceleration XG. Then, the yaw rate change accompanying the forward / backward load movement is calculated from the front / rear load movement and the target yaw rate tφ, and the acceleration / deceleration yaw rate change suppression target yaw rate tφ_Gx_ΔY necessary to suppress this as desired is determined.

  The vehicle yaw moment calculating unit 404 adds the yaw moment necessary for realizing the target yaw rate tφ and the yaw moment required for realizing the target yaw rate tφ_Gx_ΔY for suppressing acceleration / deceleration yaw rate change. Then, the vehicle moment My capable of realizing the combined target yaw rate is calculated (step S404).

  Therefore, the left and right wheel motor torque difference calculation unit 105 determines the acceleration of the left and right rear wheels 1RL and 1RR necessary to suppress the acceleration / deceleration yaw rate change based on the detected accelerator opening APO and the brake pedal depression amount BPO according to the vehicle moment My. The left and right wheel motor torque difference ΔtTm that forms the torque difference is calculated.

(Request responsiveness)
Next, the left and right wheel driving force difference request response of each DYC control will be described.
FIG. 14 shows the request responsiveness of each DYC control. As shown in this figure, the required responsiveness of the steering response DYC control and the crosswind DYC control is higher than the required responsiveness of the acceleration DYC control and the steady lateral acceleration DYC control.
Further, the response responsiveness of the steering response DYC control and the crosswind DYC control is higher than the response of the lateral acceleration YG calculated from the vehicle speed VSP and the steering angle θ, and the required responsiveness of the acceleration DYC control and the steady lateral acceleration DYC control is It has low characteristics.

  In view of this, control with a high responsiveness of the left-right torque difference with respect to the responsiveness of the lateral acceleration YG has a risk that the restriction of the common-mode limiting torque based on the lateral acceleration YG may not be in time, so the amount of restriction is set relatively large.

  That is, as shown in FIG. 15, when the responsiveness of the lateral acceleration YG is used as a reference and the responsiveness of the DYC control is lower than the responsiveness of the lateral acceleration YG, the limit amount is constant based on the responsiveness of the DYC control. Value. On the other hand, when the responsiveness of the DYC control is higher than the responsiveness of the lateral acceleration YG, the limit amount is set higher as the responsiveness is higher according to the responsiveness of the DYC control.

(Operation of Embodiment 1)
Below, based on the time chart of FIG. 7, the operation | movement at the time of execution of steering response DYC control is demonstrated as an effect | action of Embodiment 1. FIG.
FIG. 7 shows changes in driving torque when starting and accelerating from a stopped state and when steering is performed during acceleration.

  That is, in the operation example of FIG. 7, the driver depresses the accelerator pedal from time t10 to start and accelerate, and the accelerator opening APO reaches 100% at time t11. After the time t11, the accelerator opening APO = 100% is maintained and acceleration is continued, and steering is performed from the time t12, and the lateral acceleration YG is generated in the vehicle.

  In this case, until the time t12 when the steering is started, the one-wheel motor torque command value tTm, which is the left and right motor torque command values, is calculated according to the driver's accelerator operation (step S102). Further, the single-wheel motor torque command value tTm is the same value (in-phase) on the left and right, and at this point of time, the vehicle is in a straight traveling state where steering is not performed, so the maximum motor torque shown in FIG. Be regulated.

  Next, when steering is started at time t12, a limit amount is calculated according to the turning state, and the maximum value of the acceleration one-wheel torque is calculated by subtracting the limit amount from the motor maximum torque as shown in FIG. The torque is limited (steps S107 → S108).

Here, the acceleration one-wheel torque is limited by a value obtained by subtracting the limit amount from the motor maximum torque, so that the acceleration with respect to the accelerator operation may be reduced.
However, since the vehicle has started a turning operation from time t12, and the vehicle is decelerated by the running resistance during the turning, it is difficult for the driver to feel uncomfortable even if the acceleration of the vehicle decreases.
Therefore, the limit amount is set to a value corresponding to deceleration due to running resistance due to steering according to the lateral acceleration YG obtained based on the steering angle θ, so that the motor maximum torque is limited so as not to give a sense of incongruity even if deceleration occurs. It is set.

  Further, when the driver is steering, the left and right wheel motor torque difference ΔtTm based on the steering response DYC control is calculated in parallel with the calculation of the final in-phase limiting torque (steps S103 → S104 → S105). That is, the left and right wheel motor torque difference ΔtTm is obtained so as to generate the optimum vehicle moment My corresponding to the steering.

  Therefore, in this operation example, the positive and negative left and right wheel motor torque difference ΔtTm is given to the left and right electric motors 3RL and 3RR from the time t13. Then, the right and left wheel motor torque difference ΔtTm is added to the acceleration single wheel torque to obtain the final right wheel torque command value Tm_R, and the left and right wheel motor torque difference ΔtTm is subtracted from the acceleration single wheel torque to obtain the final left wheel torque command value Tm_L. The time chart of FIG. 7 shows a case where the left and right wheel motor torque difference ΔtTm is a positive value. When the left and right wheel motor torque difference ΔtTm is a negative value, the magnitude relationship between the torque command values Tm_R and Tm_L. Is the reverse of FIG.

As described above, at the time of turning, even when the accelerator opening APO is 100%, the motor maximum torque is limited from the time t12, and the maximum acceleration single wheel torque is kept lower than the motor maximum torque. ing.
For this reason, when a torque difference is given to the left and right electric motors 3RL and 3RR based on the steering response DYC control from the time point t13, the maximum motor torque can be prevented from exceeding.
In addition, the limit amount is set according to the steering angle θ so as not to give a sense of incongruity even if running resistance occurs. Therefore, the maximum value of the acceleration single wheel torque is limited to the common mode limit torque, and the accelerator opening Even if the motor torque at APO = 100% is limited, it is difficult for the driver to feel uncomfortable.
Therefore, it is possible to generate the vehicle moment My necessary for the vehicle by providing the left and right wheel motor torque difference ΔtTm for steering response DYC control while ensuring acceleration that does not give the driver a sense of incongruity.

Here, to add a description, when the steering angle θ is small and the vehicle speed VSP is low and the lateral acceleration YG is small, the limit amount is set to be relatively small. In this case, the common-mode limiting torque is a value close to the motor maximum torque, for example, as shown by a one-dot chain line in FIG.
As described above, when the steering angle θ is small and the running resistance is small, it is difficult to give the driver a sense of incongruity by suppressing the reduction in acceleration by suppressing the limit amount.
Further, when the lateral acceleration YG is low in this way, the required vehicle moment My is also small by the steering response DYC control, and the motor maximum torque can be prevented from exceeding even if the left and right wheel motor torque difference ΔtTm is added to the acceleration one-wheel torque. .

On the other hand, when the steering angle θ is large and the vehicle speed VSP is high and the lateral acceleration YG is large, the limit amount is set to be relatively large. In this case, the common-mode limiting torque can be set to a value indicated by a solid line in FIG. 4 or a lower value, for example.
As described above, when the steering angle θ is large and the running resistance is large, even if the limit amount is increased and the acceleration is reduced, it is difficult for the driver to feel uncomfortable.
Further, when the lateral acceleration YG is large as described above, the required vehicle moment My is also large due to the steering response DYC control, and the value obtained by adding the left and right wheel motor torque difference ΔtTm to the acceleration one-wheel torque is also large. A large amount can be secured so as not to exceed the maximum motor torque.

(Effect of Embodiment 1)
The effects of the vehicle driving force control apparatus according to Embodiment 1 are listed below.
1) A vehicle driving force control apparatus according to Embodiment 1
Left and right rear wheels 1RL and 1RR as drive wheels that are driven by individual electric motors 3RL and 3RR and make a pair on the left and right,
A vehicle controller 11 as a drive control device that controls the driving of the electric motors 3RL and 3RR based on detection of a sensor group 100 as a vehicle state detection device that detects a vehicle state including an operation state of a driver;
One wheel as a front-rear direction drive torque control unit included in the vehicle controller 11 for setting an acceleration one-wheel torque as a front-rear direction drive torque for the left and right rear wheels 1RL, 1RR according to the driver's required drive torque. The left and right wheel motor torque difference ΔtTm, which is a left and right rear wheel 1RL, 1RR, which is a left / right driving torque difference for vehicle state control, is set independently on the left and right sides depending on the motor torque calculation unit 102, the power performance limiting unit 109, and the vehicle state. A target yaw rate calculation unit 103, a vehicle moment calculation unit 104, a left and right wheel motor torque difference calculation unit 105 as wheel drive torque difference setting units;
A vehicle driving force control device comprising:
The vehicle controller 11 is provided with a power performance limit amount calculation unit 108 as a limit amount setting unit that sets a limit amount for limiting the maximum motor torque according to the steering angle θ obtained from the sensor group 100. To do.
Therefore, during acceleration turning, the left and right wheel motor torque difference ΔtTm is set independently on the left and right sides according to the vehicle state while driving the electric motors 3RL and 3RR based on the acceleration single wheel torque according to the acceleration operation of the driver. , Improve turning performance.
At this time, since the motor torque is limited by the maximum motor torque, if priority is given to the control that gives the driving force difference between the left and right, the driving force for acceleration cannot be secured sufficiently when shifting from straight to turning during acceleration. There is a fear.
On the other hand, the power performance limit amount calculation unit 108 sets the common-mode limit torque in which the motor maximum torque is limited by the limit amount according to the steering angle θ. That is, during cornering, cornering resistance is generated, resulting in a reduction in acceleration performance. Therefore, by setting a limiting amount (common mode limiting torque) according to the cornering resistance, it becomes possible to limit the acceleration one-wheel torque that is the front-rear driving torque without giving a sense of incongruity.
This makes it possible to limit the torque of the electric motors 3RL and 3RR so as not to exceed the motor maximum torque without making the driver feel uncomfortable during turning.

2) The vehicle driving force control apparatus according to Embodiment 1
The power performance limit amount calculation unit 108 serving as the limit amount setting unit estimates a lateral acceleration YG in a turning state based on the steering angle θ and the vehicle speed VSP obtained from the sensor group 100, and determines the estimated lateral acceleration YG. The limit amount is determined accordingly.
Therefore, the limiting amount (common-mode limiting torque) can be determined in accordance with the magnitude of the cornering resistance, and the limiting amount that does not give the driver an uncomfortable feeling can be set.
Further, the lateral acceleration YG, which is a turning state corresponding to the cornering resistance, can be detected before the actual vehicle behavior (lateral acceleration Gy) occurs. Compared with the case where the limit amount is set after the vehicle behavior occurs. Thus, high control responsiveness can be obtained.

3) The vehicle driving force control apparatus according to Embodiment 1 is
The power performance limit amount calculation unit 108 as the limit amount setting unit sets the regeneration side limit amount so as to be less than the acceleration side limit amount.
That is, during regeneration, a braking force is generated by the motor torque. For this reason, when the amount of restriction becomes relatively large, the braking force due to regeneration is restricted, and there is a risk that the braking force may be lost during turning. Thus, by suppressing the regeneration-side limit amount more than the acceleration-side limit amount, it is possible to suppress the occurrence of this feeling of braking force loss.
Therefore, the uncomfortable feeling given to the driver can be suppressed by accurately setting the limit amount of the motor torque corresponding to the direction in which the motor torque acts.

4) The vehicle driving force control apparatus according to Embodiment 1
The front-rear direction drive torque control unit sets the one-wheel motor torque command value tTm as the front-rear direction drive torque according to the driver required drive torque from the accelerator opening APO obtained from the sensor group 100 and the vehicle speed VSP. A single-wheel motor torque calculation unit 102 as a torque setting unit;
The one-wheel motor torque calculation unit 102 can obtain a common-mode limit torque, which is the maximum torque when the motor maximum torque is limited by the limit amount, at the maximum accelerator opening APO (100%) according to the limit amount. The characteristic of the single wheel motor torque command value tTm corresponding to the accelerator opening APO is changed.
If the limit amount is simply set without changing the characteristic of the single wheel motor torque command value tTm corresponding to the accelerator opening APO, it is limited by the common mode limit torque before reaching the maximum accelerator opening (the common mode limit torque is There is a risk of reaching. In this case, a dead zone in which the one-wheel motor torque command value tTm does not change occurs in the region from the accelerator opening when the common-mode limit torque is reached to the maximum accelerator opening.
On the other hand, in the first embodiment, the accelerator opening APO is set so that the maximum torque (in-phase limit torque) when the motor maximum torque is limited by the limit amount can be obtained by the maximum accelerator opening APO (100%). The characteristic of the corresponding one-wheel motor torque command value tTm is changed. Thereby, it is possible to eliminate such a dead zone, and it becomes more difficult to give the driver a sense of incongruity in acceleration performance.

5) The vehicle driving force control apparatus of Embodiment 1
The power performance limit amount calculation unit 108 as the limit amount setting unit adjusts the limit amount based on responsiveness of control for setting the left and right wheel motor torque difference ΔtTm according to the vehicle state.
Therefore, an optimal limit amount can be set according to the response of the left and right wheel motor torque difference ΔtTm.
Specifically, the control with higher responsiveness of the left and right wheel motor torque difference ΔtTm than the responsiveness of the lateral acceleration YG obtained by estimating the steering state is in-phase compared to the control with low control responsiveness. Increase the torque limit relatively. Thereby, it can suppress that the limitation by the common mode limiting torque based on the lateral acceleration YG is delayed with respect to the control of the left and right wheel motor torque difference ΔtTm.

6) The vehicle driving force control apparatus of Embodiment 1
In the control for setting the left and right wheel motor torque difference ΔtTm of the power performance limit amount calculation unit 108 as the limit amount setting unit, the steering angle θ and the vehicle speed VSP obtained by the steering angle sensor 113 of the vehicle state detection device are used. Accordingly, steering response DYC control, which is control for setting the left and right wheel motor torque difference ΔtTm, is included.
Therefore, with respect to the steering response DYC control in which the left and right wheel motor torque difference ΔtTm is set according to the steering angle θ and the vehicle speed VSP obtained by the vehicle state detection device, the setting of the limit amount is not delayed and at an appropriate timing. It is possible to set.

7) The vehicle driving force control apparatus of Embodiment 1
In the control for setting the left and right wheel motor torque difference ΔtTm of the power performance limit amount calculation unit 108 as the limit amount setting unit, the left and right wheel motors are set according to the yaw rate φ obtained by the yaw rate sensor 114 of the vehicle state detection device. A crosswind DYC control that is a control for setting the torque difference ΔtTm is included.
Therefore, the setting of the common-mode limit torque as the limit amount is set at an appropriate timing without delay for the cross wind DYC control that sets the left and right wheel motor torque difference ΔtTm according to the yaw rate φ obtained by the vehicle state detection device. Is possible.

8) The vehicle driving force control apparatus according to Embodiment 1
In the control for setting the left and right wheel motor torque difference ΔtTm of the power performance limit amount calculation unit 108 as the limit amount setting unit, vehicle acceleration obtained by the accelerator opening sensor 112 and the brake pedal sensor 118 of the vehicle state detection device is used. Acceleration / deceleration DYC control as control for setting the left and right wheel motor torque difference ΔtTm according to deceleration is included.
Therefore, with respect to the acceleration / deceleration DYC control that sets the left and right wheel motor torque difference ΔtTm according to the vehicle acceleration / deceleration obtained by the vehicle state detection device, the setting of the common-mode limit torque as the limit amount is not delayed. It is possible to set with.

9) The vehicle driving force control apparatus according to Embodiment 1
The control for setting the left and right wheel motor torque difference ΔtTm of the power performance limit amount calculation unit 108 as the limit amount setting unit is performed according to the lateral acceleration Gy of the vehicle obtained by the lateral acceleration sensor 116 of the vehicle state detection device. It is characterized in that steady lateral acceleration DYC control is included as control for setting the left-right drive torque difference.
Accordingly, the setting of the common-mode limiting torque as the limiting amount is not delayed with respect to the steady lateral acceleration DYC control that sets the left and right wheel motor torque difference ΔtTm according to the lateral acceleration Gy of the vehicle obtained by the vehicle state detection device. It is possible to set at an appropriate timing.

  As mentioned above, although the transmission device of the hybrid vehicle of the present invention has been described based on the embodiment, the specific configuration is not limited to this embodiment, and the invention according to each claim of the claims Design changes and additions are permitted without departing from the gist of the present invention.

For example, although the one-wheel motor torque calculation part showed the example which calculates | requires a motor torque command value from an accelerator opening, a vehicle speed, and an in-phase limiting torque, it is not limited to this.
Specifically, the single wheel motor torque command value tTm may be obtained from the accelerator opening APO and the vehicle speed VSP. In this case, it may be obtained by a map as shown in the first embodiment, but may be obtained by a target acceleration calculating unit 01 and a single wheel motor torque calculating unit 02 as shown in FIG.
The target acceleration calculation unit 01 reads the accelerator opening APO and the vehicle speed VSP, and obtains a vehicle target acceleration α, which is a vehicle target acceleration requested by the driver, based on a preset map. Then, the obtained vehicle target acceleration α is output to the one-wheel motor torque calculation unit 02 and converted into torque. As is well known, the vehicle target acceleration setting map is set to a higher value as the accelerator opening is larger, and is set to a lower value as the vehicle speed is higher at the accelerator opening.
The single-wheel motor torque calculation unit 02 calculates a single-wheel motor torque command value tTm to be output to each of the left and right electric motors from the vehicle target acceleration α calculated by the target acceleration calculation unit 01 by the following equation (4). .
tTm = α × W × (1 / i) × Rw × (1/2) (4)
Α is a vehicle target acceleration, W is a vehicle weight W, i is a transmission gear ratio, and Rw is a tire moving radius.

  In the first embodiment, the accelerator opening degree sensor and the brake pedal sensor are used to detect the acceleration / deceleration of the vehicle. However, the acceleration / deceleration of the vehicle is detected using the detection values of the wheel speed sensor and the longitudinal acceleration sensor. You may do it.

1RL Left rear wheel (drive wheel)
1RR Right rear wheel (drive wheel)
3RL Electric motor 3RR Electric motor 11 Vehicle controller (drive control device)
100 sensor group (vehicle state detection device)
102 Single-wheel motor torque calculation unit (front-rear direction drive torque control unit: drive torque setting unit)
103 Target yaw rate calculation unit (right and left wheel drive torque difference setting unit)
104 Vehicle moment calculation unit (left and right wheel drive torque difference setting unit)
105 Left and right wheel motor torque difference calculation unit (left and right wheel drive torque difference setting unit)
106 Turning state estimation unit 108 Power performance limit amount calculation unit (limit amount setting unit)
109 Power performance limiting unit (front-rear direction driving torque control unit)
112 Accelerator opening sensor 113 Steering angle sensor 114 Yaw rate sensor 115 Longitudinal acceleration sensor 116 Lateral acceleration sensor 118 Brake pedal sensor

Claims (9)

Drive wheels driven by individual electric motors and paired on the left and right,
A drive control device for controlling the driving of the electric motor based on detection by a vehicle state detection device that detects a vehicle state including an operation state of a driver;
A front-rear direction drive torque control unit included in the drive control device for setting a front-rear direction drive torque for the left and right drive wheels according to the driver's required drive torque for the vehicle; A left and right wheel drive torque difference setting unit that sets left and right drive torque difference for vehicle state control on the drive wheels independently;
A vehicle driving force control device comprising:
A driving force control apparatus for a vehicle, wherein the driving control apparatus is provided with a limiting amount setting unit that sets a limiting amount for limiting the maximum motor torque in accordance with a steering angle obtained from the vehicle state detection device. The vehicle driving force control device according to claim 1,
The limit amount setting unit estimates a turning state based on a steering angle and a vehicle speed obtained from the vehicle state detection device, and determines the limit amount according to the estimated turning state. Force control device. In the vehicle driving force control device according to claim 1 or 2,
The vehicular driving force control device is characterized in that the limit amount setting unit sets the regeneration side limit amount to be less than the acceleration side limit amount. In the vehicle driving force control device according to any one of claims 1 to 3,
The front-rear direction drive torque control unit includes a drive torque setting unit that sets the front-rear direction drive torque from an accelerator opening and a vehicle speed obtained from the vehicle state detection device,
The driving torque setting unit corresponds to the front-rear direction corresponding to the accelerator opening so that the maximum torque when the motor maximum torque is restricted by the restriction amount can be obtained by the maximum accelerator opening according to the restriction amount. A driving force control apparatus for a vehicle, wherein the driving torque characteristic is changed. In the vehicle driving force control device according to any one of claims 1 to 4,
The vehicular driving force control apparatus, wherein the limiting amount setting unit adjusts the limiting amount based on responsiveness of control for setting the left / right driving torque difference according to the vehicle state. In the vehicle driving force control device according to claim 5,
The control for setting the left and right driving torque difference of the limit amount setting unit includes control for setting the left and right driving torque difference according to a steering angle and a vehicle speed obtained by the vehicle state detection device. A vehicle driving force control device. In the vehicle driving force control device according to claim 5 or 6,
Control for setting the left / right driving torque difference of the limit amount setting unit includes control for setting the left / right driving torque difference according to a yaw rate obtained by the vehicle state detection device. Force control device. In the vehicle driving force control device according to any one of claims 5 to 7,
The control for setting the left / right driving torque difference of the limit amount setting unit includes a control for setting the left / right driving torque difference according to vehicle acceleration / deceleration obtained by the vehicle state detection device. Driving force control device. In the vehicle driving force control device according to any one of claims 5 to 8,
The control for setting the left and right driving torque difference of the limit amount setting unit includes a control for setting the left and right driving torque difference according to the vehicle lateral acceleration obtained by the vehicle state detecting device. Driving force control device.