JP7571585B2 - Vehicle control device - Google Patents

Description

This invention relates to a vehicle control device equipped with multiple actuators, such as a drive motor and a brake mechanism, for controlling the driving force and braking force of the vehicle, as well as vehicle behavior such as rolling and pitching.

Patent document 1 describes a vehicle control device that controls the driving force and braking force of the driving wheels to drive the vehicle appropriately and simultaneously controls multiple behaviors occurring in the vehicle body. The vehicle control device described in this patent document 1 includes a braking/driving force generating mechanism (actuator) that generates a driving force or braking force independently for each wheel of the vehicle, a suspension mechanism that connects each wheel arranged under the spring of the vehicle to a vehicle body arranged on the spring of the vehicle, and a control means that controls the braking/driving force generating mechanism to generate an independent driving force or braking force for each wheel. The control means detects the operation state of the vehicle by the driver and the motion state generated in the vehicle body when the vehicle is traveling, and calculates a target longitudinal driving force for traveling the vehicle and multiple target motion state quantities for controlling the behavior of the vehicle body based on at least the operation state of the vehicle and the motion state of the vehicle body. Then, the driving force (target driving force) or braking force (target braking force) to be distributed to each wheel and generated independently for each wheel is calculated so as to realize the calculated target longitudinal driving force and multiple target motion state quantities.

JP 2012-86712 A

A vehicle equipped with the control device described in the above Patent Document 1 is provided with, for example, a drive motor (i.e., a so-called in-wheel motor) that directly drives each wheel as an actuator for generating a driving force and a braking force and controlling the behavior of the vehicle (for example, the vehicle's longitudinal acceleration, rolling, pitching, yawing, etc.). In addition, each wheel is provided with a brake device that brakes each wheel independently. The vehicle control device described in Patent Document 1 individually controls the drive motor of each wheel or the brake device of each wheel to generate the target driving force or target braking force calculated as described above. For example, the ratio of the driving force or braking force to be distributed to the front and rear wheels is controlled. Alternatively, the ratio of the driving force or braking force to be distributed to the front and rear wheels is controlled. In this way, the target longitudinal driving force and multiple target motion state quantities are realized.

However, the actuator that distributes the driving force or braking force as described above may have its output or operation limited depending on its operating state or output condition. For example, the output of the driving motor may be limited due to the upper limit torque or temperature of the driving motor. In addition, the output of the battery that supplies power to the driving motor may be limited, resulting in the output of the driving motor being limited. Alternatively, the operation of the brake device may be limited due to a rise in temperature of the friction material of the brake device. If the output of either the front or rear driving motor is limited, the balance (ratio) of the front and rear driving force distribution will be lost. Alternatively, if the operation of either the left or right brake device is limited, the balance (ratio) of the left and right braking force distribution will be lost. As a result, there is a risk that the vehicle's behavior will become unstable.

This invention was conceived with a focus on the above technical problems, and aims to provide a vehicle control device that can appropriately control the vehicle's behavior even when there are restrictions on the output and operation of the actuators that control the vehicle's behavior.

In order to achieve the above object, the present invention provides a vehicle control device that has a plurality of actuators that can be controlled individually, and controls vehicle behavior by operating the plurality of actuators , the vehicle control device comprising at least two power supply systems, a first power supply system and a second power supply system, and a controller that controls the output or operation of the actuators , the actuators having at least two motors, a first motor that is connected to the first power supply system to receive and transmit power, and a second motor that is connected to the second power supply system to receive and transmit power, the controller determines a state in which the output or operation of the actuators is restricted, and when the output or operation of any of the actuators is restricted, The present invention is characterized in that it limits the output or operation of the other actuator whose output or operation is not in a limited state, and further, when the output of either the first motor or the second motor is in a limited state, it limits the output of the other of the first motor or the second motor whose output is not in a limited state, and determines a state in which the outputs of the first power supply device and the second power supply device are limited, and when the output of either the first power supply device or the second power supply device is in a limited state, it limits the output of the motor connected to the other of the first power supply device or the second power supply device whose output is not in a limited state .

The vehicle to be controlled by the vehicle control device of the present invention is equipped with a plurality of actuators, such as a torque vectoring device that controls the distribution ratio of the driving torque or braking torque to be distributed to each of the front, rear, left and right wheels (four wheels), a so-called in-wheel motor that is provided on each of the front, rear, left and right wheels (four wheels) and can independently control the driving force of each wheel, a brake device that is provided on each of the front, rear, left and right wheels (four wheels) and can independently control the braking force of each wheel, or a so-called active suspension device that is provided on each of the front, rear, left and right wheels (four wheels) and can independently control the spring constant and damping force of the suspension of each wheel. Then, the vehicle behavior such as rolling, pitching, and yawing is controlled by controlling each of the plurality of actuators. For example, the vehicle rolling state is controlled by controlling the distribution ratio of the driving force or braking force to the left and right wheels. Alternatively, the vehicle pitching state (or squat state and nose dive state) is controlled by controlling the distribution ratio of the driving force or braking force to the front and rear wheels. In this way, the output or operation of the actuators that control the vehicle behavior may be limited depending on the operating state, output state, etc. of the actuators. Therefore, when the output or operation of any one or some of the actuators is limited, the balance of the driving force, braking force, etc. of each wheel may be lost, and the vehicle behavior may become unstable. In contrast, in the vehicle control device of the present invention, when the output or operation of any one or some of the actuators is limited, the output or operation of the other actuators whose output or operation is not limited is also limited. For example, when the output or operation of any one actuator is limited (or is limited) due to some constraint condition, the output or operation of the other actuators that are normal, i.e., whose output or operation is not limited, and are controlled together with the actuator whose output or operation is limited, are limited to the same extent as the actuator whose output or operation is limited. Therefore, although the total output of the actuators as a whole is reduced, it is possible to avoid or suppress a situation in which the balance of the driving force, braking force, etc. of each wheel is lost, resulting in unstable vehicle behavior. Therefore, with the vehicle control device of the present invention, when only the output or operation of one of the actuators is restricted, it is possible to prevent imbalance of the driving force, braking force, etc. that control the vehicle behavior, and to appropriately control the vehicle behavior.

The vehicle to be controlled by the vehicle control device of the present invention is equipped with at least a first actuator and a second actuator that are paired front to back or left to right. The first actuator and the second actuator are controlled, respectively, to control vehicle behavior such as rolling, pitching, and yawing. In addition, in the vehicle control device of the present invention, when the output or operation of either the first actuator or the second actuator (e.g., the first actuator) is in a state in which the output or operation is limited, the output or operation of the other actuator (e.g., the second actuator) whose output or operation is not limited is also limited. For example, when the output or operation of the first actuator is in a state in which the output or operation of the first actuator is limited due to some constraint condition or the occurrence of a failure, the output or operation of the second actuator that is normal, i.e., whose output or operation is not limited, and that is controlled in a pair with the first actuator, is limited to the same extent as the first actuator. Therefore, although the total output of the actuators as a whole, including the first actuator and the second actuator, is reduced, it is possible to avoid or suppress a situation in which the vehicle behavior becomes unstable due to an imbalance in the driving force, braking force, etc. of each wheel. Therefore, according to the vehicle control device of the present invention, when the output or operation of only one of the first actuator or the second actuator is limited, it is possible to suppress imbalance in the driving force, braking force, etc. that control the vehicle behavior, and to appropriately control the vehicle behavior.

The vehicle to be controlled by the vehicle control device of the present invention is equipped with at least two power supply systems, a first power supply device and a second power supply device. The vehicle is also equipped with at least two motors, a first motor connected to the first power supply device to receive and transmit power (i.e., the first motor is driven by power supplied from the first power supply device and supplies regenerative power to the first power supply device to charge the first power supply device), and a second motor connected to the second power supply device to receive and transmit power (i.e., the second motor is driven by power supplied from the second power supply device and supplies regenerative power to the second power supply device to charge the second power supply device). The vehicle control device controls the first motor and the second motor, respectively, to control vehicle behavior such as rolling, pitching, and yawing. In addition, in the vehicle control device of the present invention, when the output of either the first motor or the second motor (e.g., the first motor) is in a state in which the output is limited, the output of the other motor (e.g., the second motor) whose output is not in a state in which the output is limited is also limited. For example, when the output of the first motor is limited due to constraints such as the upper limit torque or temperature of the motor, or the occurrence of a failure, the output of the second motor paired with the first motor and normal, i.e., not limited in output or operation, is limited to the same extent as the first motor. Also, when the output of either one of the first power supply device or the second power supply device (e.g., the first power supply device) is limited, the output of the motor (i.e., the second motor) connected to the other power supply device (e.g., the second power supply device) whose output is not limited is also limited. For example, when the output of the first power supply device is limited due to constraints such as the SOC (State Of Charge) or temperature of the battery, or the occurrence of a failure, the output of the second motor paired with the first power supply device and connected to the second power supply device which is normal, i.e., not limited in output or operation, is limited to the same extent as the first motor whose output is limited due to the limit on the output of the first power supply device. Therefore, although the total output of the actuator as a whole, which combines the first motor and the second motor, is reduced, it is possible to avoid or suppress a situation in which the vehicle behavior becomes unstable due to a loss of balance between the driving force and braking force of each wheel. Therefore, according to the vehicle control device of the present invention, when the output of only one of the first power supply device or the second power supply device is limited, and when the output of only one of the first motor or the second motor is limited, it is possible to suppress the loss of balance between the driving force and braking force that control the vehicle behavior, and to appropriately control the vehicle behavior.

1 is a diagram showing an example of a configuration and control system of a vehicle to be controlled by a vehicle control device of the present invention; FIG. 2 is a diagram showing an overview of the configurations and positional relationships of the components of the vehicle shown in FIG. 1 , including a “second motor (rear wheel drive motor)”, a “second torque vectoring device (electric torque distribution differential device with a differential limiting mechanism)”, an “electric parking brake”, and an “on-board brake device (electromagnetic brake)”. 1 is a flowchart for explaining an example of control executed by the vehicle control device of the present invention (a control example in which a restriction is imposed on the control target value of the driving force or braking force acting on each wheel when a restriction is imposed on any one of the wheels). 1A is a diagram illustrating the forces and moments acting on the center of gravity of the vehicle, and FIG. 1B is a diagram illustrating the forces acting on the wheels of the vehicle, and FIG. 11 is a flowchart for explaining another example of the control contents executed by the vehicle control device of the present invention (a control example in which, when a restriction is imposed on any one of the wheels, a restriction is imposed on the control input value of the driving force or braking force acting on each wheel, and a control input value of the moment acting on the vehicle body). A flowchart to explain another example of the control contents executed by the vehicle control device of this invention (a control example in which a limit is imposed on the control target values of the triaxial forces acting on each wheel when a limit is imposed on any one of the wheels). 11 is a flowchart for explaining another example of the control contents executed by the vehicle control device of the present invention (a control example in which restrictions are imposed on the control input values of the three-axial forces acting on each wheel and the control input value of the moment acting on the vehicle body when restrictions are imposed on any one of the wheels). 11 is a flowchart for explaining another example of the control contents executed by the vehicle control device of the present invention (a control example in which, when a restriction is imposed on one of the two power supply systems (front and rear) (batteries), a restriction is imposed on the motor connected to the other power supply system (battery), thereby maintaining the torque distribution between the front and rear wheels). FIG. 9 is a diagram showing an image of a map that is set based on the “battery temperature-torque upper limit characteristic” that is applied when calculating the upper limit of motor torque in the control shown in the flowchart of FIG. 8 . 9 is a diagram for explaining the content and action/effect of “torque distribution correction due to battery constraints (maintaining front/rear distribution ratio)” executed in the control shown in the flowchart of FIG. 8 . FIG. 11 is a flowchart for explaining another example of the control executed by the vehicle control device of the present invention (a control example in which, when a restriction is imposed on one of two power supply devices (batteries) (front and rear), the control for the motor connected to the other power supply device (battery) is corrected to maintain the yaw rate acting on the vehicle body). 12 is a flowchart for explaining the control executed after a positive determination is made in step S53 in the control shown in the flowchart of FIG. 11. 13 is a diagram for explaining the contents and effects of "torque distribution correction due to battery constraints (maintenance of yaw rate)" executed by the control shown in the flowcharts of FIGS. 11 and 12. FIG. 11 is a flowchart for explaining another example of the control executed by the control device of the vehicle of the present invention (a control example for changing the “constraint (limit) compliant mode” according to the state of the power supply device (battery) when there is little margin for the battery constraint). FIG. 15 is a diagram showing an image of a map used when determining a "state in which there is little margin until the battery constraint" in the control shown in the flowchart of FIG. 14, and is a diagram for explaining a "preparation area for battery temperature."

The embodiment of the present invention will be described with reference to the drawings. Note that the embodiment shown below is merely an example of how the present invention can be realized, and is not intended to limit the present invention.

Figure 1 shows an example of a drive system and control system of a vehicle Ve to be controlled in an embodiment of the present invention. The main components of the vehicle Ve shown in Figure 1 include a first motor (MG) 1, a second motor (MG) 2, a first torque vectoring device (TVD) 3, a second torque vectoring device (TVD) 4, a first power supply device (BAT) 5, a second power supply device (BAT) 6, a first brake device 7, a second brake device 8, a third brake device 9, a fourth brake device 10, a detection unit 11, and a controller (ECU) 12.

The first motor 1 converts electrical energy into mechanical energy (or rotational energy) or converts mechanical energy (or rotational energy) into electrical energy. The first motor 1 is connected to the left and right front wheels (fl) 13 and the front wheel (fr) 14 so as to be capable of transmitting power via the first torque vectoring device 3 described below. The first motor 1 is a motor having a power generating function (a so-called motor generator), and is configured, for example, by a permanent magnet synchronous motor or an induction motor. In the embodiment shown in FIG. 1, the first motor 1 is configured by a permanent magnet synchronous motor as a drive power source for the front wheels 13, 14.

The second motor 2 converts electrical energy into mechanical energy (or rotational energy) or converts mechanical energy (or rotational energy) into electrical energy. The second motor 2 is connected to the left and right rear wheels (rl) 15 and the rear wheel (rr) 16 so as to be capable of transmitting power via the first torque vectoring device 3 described below. The second motor 2 is a motor having a power generating function (a so-called motor generator), and is configured, for example, by a permanent magnet synchronous motor or an induction motor. In the embodiment shown in FIG. 1, the second motor 2 is configured by an induction motor as a drive power source for the rear wheels 15, 16.

The first torque vectoring device 3 is an electric torque distribution differential device that functions as a differential device for the left and right front wheels 13, 14 and distributes and transmits the output torque of the first motor 1 to the left and right front wheels 13, 14. Like the second torque vectoring device 4 described later, the first torque vectoring device 3 is composed of, for example, two sets of planetary gear mechanisms (not shown), a reversing gear mechanism (not shown) that connects and reverses the ring gears (not shown) of the two sets of planetary gear mechanisms, an input gear mechanism (not shown) to which the torque is transmitted from the first motor 1, and a differential motor (not shown) that controls the differential state and torque distribution state (allocation ratio) of the left and right output shafts (not shown) connected to the left and right front wheels 13, 14, respectively. Also, like the second torque vectoring device 4 described later, the first torque vectoring device 3 may be provided with a differential limiting mechanism (not shown) that limits the differential state of the left and right output shafts.

The second torque vectoring device 4 is an electric torque distribution differential device that functions as a differential device for the left and right rear wheels 15, 16 and distributes and transmits the output torque of the second motor 2 to the left and right rear wheels 15, 16. As shown in FIG. 2, the second torque vectoring device 4 is composed of, for example, two planetary gear mechanisms 4a, 4b, a reversing gear mechanism 4c that connects and reverses the ring gears (not shown) of the two planetary gear mechanisms, an input gear mechanism 4d to which the torque is transmitted from the first motor 1, and a differential control motor 4e that controls the differential state and torque distribution state (distribution ratio) of the left and right output shafts (not shown) connected to the left and right rear wheels 15, 16, respectively. In the embodiment shown in FIG. 2, the second torque vectoring device 4 is provided with a differential limiting mechanism (electromagnetic brake of non-excitation operation type) 4f that limits the differential state of the left and right output shafts.

The vehicle Ve in this embodiment of the invention is equipped with at least two power supply systems, a first power supply device 5 and a second power supply device 6. The first power supply device 5 has, for example, an inverter (not shown) and a battery (not shown), and the battery and the first motor 1 are connected via the inverter. The first power supply device 5 supplies power to the first motor 1 to drive the first motor 1. The first power supply device 5 also receives power (regenerative power) generated by the first motor 1 to charge the battery. That is, the first power supply device 5 is connected to the first motor 1 and exchanges power with the first motor 1. The first power supply device 5 is also connected to a differential control motor (not shown) of the first torque vectoring device 3, and supplies power to the differential control motor of the first torque vectoring device 3 to drive the differential control motor.

On the other hand, the second power supply device 6 has, for example, an inverter (not shown) and a battery (not shown), and the battery and the second motor 2 are connected via the inverter. The second power supply device 6 supplies power to the second motor 2 to drive the second motor 2. The second power supply device 6 also receives power (regenerative power) generated by the second motor 2 to charge the battery. That is, the second power supply device 6 is connected to the second motor 2 and exchanges power with the second motor 2. The second power supply device 6 is also connected to the differential control motor 4e of the second torque vectoring device 4, and supplies power to the differential control motor 4e to drive the differential control motor 4e.

The first brake device 7, the second brake device 8, the third brake device 9, and the fourth brake device 10 are all devices that generate a braking force for the vehicle Ve, and are activated when braking the vehicle Ve to generate a braking torque. In the embodiment shown in FIG. 1, the first brake device 7 generates a braking force on the left front wheel 13 of the vehicle Ve. The second brake device 8 generates a braking force on the right front wheel 14 of the vehicle Ve. The third brake device 9 generates a braking force on the left rear wheel 15 of the vehicle Ve. And the fourth brake device 10 generates a braking force on the right rear wheel 16 of the vehicle Ve.

In the embodiment shown in FIG. 2, the vehicle Ve is provided with an electric parking brake device 17 and an on-board brake device 18. The electric parking brake device 17 is driven by an electric motor (not shown) or an electromagnet (not shown), and locks the rotation of the input gear mechanism 4d to maintain the vehicle Ve in a stopped state. The on-board brake device 18 is, for example, configured with an electromagnetic brake (not shown), and generates a braking torque and transmits the braking torque to the left and right output shafts via the input gear mechanism 4d.

The detection unit 11 is a device or apparatus for acquiring various data and information required for controlling the vehicle Ve, and includes, for example, a power supply unit, a microcomputer, a sensor, an input/output interface, etc. Specifically, the detection unit 11 in this embodiment of the present invention includes:
The vehicle includes, as sensors for detecting the operation state of the vehicle Ve by the driver, an accelerator position sensor 11a for detecting the amount of operation (i.e., accelerator position or accelerator opening) and operation speed of an accelerator pedal (not shown) by the driver, a brake stroke sensor (or brake switch) 11b for detecting the amount of operation and the pressing force of a brake pedal (not shown) by the driver, and a steering sensor (or steering angle sensor) 11c for detecting the amount of operation of the steering wheel by the driver and the corresponding steering angle. The vehicle also includes, as sensors for detecting the motion state (vehicle behavior), a wheel speed sensor 11d for detecting the rotation speeds of the wheels 13, 14, 15, and 16 to calculate the vehicle speed, an acceleration sensor 11e for detecting the acceleration (longitudinal acceleration and lateral acceleration) of the vehicle Ve, and a yaw rate sensor 11f for detecting or calculating the yaw rate of the vehicle Ve. As sensors for detecting the state of the first motor 1 and the state of the second motor 2, for example, a motor rotation speed sensor (or resolver) 11g for detecting the rotation speed of the first motor 1 and the rotation speed of the second motor 2, a motor temperature sensor 11h for detecting the temperature (or oil temperature) of the first motor 1 and the temperature (or oil temperature) of the second motor 2, and a motor torque sensor 11i for detecting the load (or torque) of the first motor 1 and the load (or torque) of the second motor 2. Furthermore, as sensors for detecting the state of the first power supply device 5 and the state of the second power supply device 6, for example, a battery temperature sensor 11j for detecting the temperature of the battery in the first power supply device 5 and the temperature of the battery in the second power supply device 6, and an SOC sensor 11k for detecting the SOC of the battery in the first power supply device 5 and the SOC of the battery in the second power supply device 6, are provided. The detection unit 11 is electrically connected to a controller 12 (described later) and outputs an electrical signal corresponding to the detected or calculated values of the various sensors, instruments, devices, etc. described above to the controller 12 as detection data.

The controller 12 is an electronic control device mainly composed of a microcomputer, for example. In the embodiment of the present invention, the controller 12 mainly controls the operation of the first motor 1, the second motor 2, the first torque vectoring device 3, the second torque vectoring device 4, the first brake device 7, the second brake device 8, the third brake device 9, and the fourth brake device 10. The controller 12 receives various data detected or calculated by the detection unit 11. The controller 12 performs calculations using the various input data and pre-stored data and calculation formulas. The controller 12 outputs the calculation results as control command signals and is configured to control the operation of the drive motors 1 and 2, the torque vectoring devices 3 and 4, and the brake devices 7, 8, 9, and 10, as described above. Note that while FIG. 1 shows an example in which one controller 12 is provided, multiple controllers 12 may be provided, for example, for each device or equipment to be controlled, or for each control content.

As described above, the vehicle Ve in the embodiment of the present invention is provided with a plurality of actuators that can be controlled individually. That is, in the embodiment shown in FIG. 1 and FIG. 2, the vehicle Ve is provided with a pair of front and rear actuators, a first motor 1 that drives the front wheels 13 and 14, and a second motor that drives the rear wheels 15 and 16. The vehicle Ve is also provided with a pair of front and rear actuators, a first torque vectoring device 3 that distributes and transmits the output torque of the first motor 1 to the front wheels 13 and 14, and a second torque vectoring device 4 that distributes and transmits the output torque of the second motor 2 to the rear wheels 15 and 16. The vehicle Ve is further provided with a first brake device 7 that brakes the front wheels 13, a second brake device 8 that brakes the front wheels 14, a third brake device 9 that brakes the rear wheels 15, and a fourth brake device 10 that brakes the rear wheels 16. These four brake devices 7, 8, 9, and 10 can be controlled independently of each other. For example, the first brake device 7 and the second brake device 8, and the third brake device 9 and the fourth brake device 10 can be controlled as a pair of actuators on the front and rear. Alternatively, the first brake device 7 and the third brake device 9, and the second brake device 8 and the fourth brake device 10 can be controlled as a pair of actuators on the left and right.

The controller 12 in this embodiment of the present invention controls the motion state of the vehicle Ve, i.e., the vehicle behavior, by controlling each of the multiple actuators as described above. For example, the first motor 1 and the second motor 2 are independently controlled to control the drive force distribution between the front wheels 13, 14 and the rear wheels 15, 16 of the vehicle Ve. Alternatively, the first torque vectoring device 3 and the second torque vectoring device 4 are independently controlled to control the drive force distribution between the left front wheel 13 and the right front wheel 14 of the vehicle Ve, and the drive force distribution between the left rear wheel 15 and the right rear wheel 16 of the vehicle Ve. Therefore, by independently and cooperatively controlling the first motor 1 and the second motor 2, and the first torque vectoring device 3 and the second torque vectoring device 4, the drive force distribution between the wheels 13, 14, 15, 16 can be controlled. In addition, by independently controlling each of the brake devices 7, 8, 9, and 10, it is possible to control the braking force distribution (driving force distribution minus the braking force component) between each of the wheels 13, 14, 15, and 16. In this way, by controlling the driving force distribution or braking force distribution between each of the wheels 13, 14, 15, and 16, it is possible to control vehicle behavior such as rolling, pitching, and yawing. For example, by controlling the distribution ratio of the driving force or braking force to the left and right wheels (front wheels 13 and rear wheels 15 and front wheels 14 and rear wheels 16), it is possible to control the rolling state of the vehicle Ve. Alternatively, by controlling the distribution ratio of the driving force or braking force to the front and rear wheels (front wheels 13, 14 and rear wheels 15, 16), it is possible to control the pitching state (or squat state and nose dive state) of the vehicle.

Note that the vehicle to be controlled by the vehicle control device in the embodiment of the present invention is not limited to the vehicle Ve shown in FIG. 1 and FIG. 2 as described above. For example, a vehicle equipped with a so-called in-wheel motor that is provided separately for each of the front, rear, left and right wheels (four wheels) and can independently control the driving force of each wheel, as shown in FIG. 1 of the above-mentioned Patent Document 1 and FIG. 1 of JP-A-2019-108104, can be the control target. Alternatively, a vehicle equipped with a so-called active suspension device that is provided separately for each of the front, rear, left and right wheels (four wheels) and can independently control the spring constant and damping force of the suspension of each wheel, can be the control target. Alternatively, a vehicle equipped with two sets of steering devices (a first steering actuator on the front wheel side and a second steering actuator on the rear wheel side) that are provided separately for each of the front and rear wheels and can independently control the steering angle of the front wheels and the steering angle of the rear wheels, as shown in FIG. 1 of JP-A-2019-108104, can be the control target.

As mentioned above, the output and operation of the actuators that control the vehicle behavior as described above may be limited depending on their operating state and output state. For example, when the driving force requirements and braking force requirements for each wheel 13, 14, 15, 16 are different, the loads on the first motor 1 and the second motor, the loads on the in-wheel motors of each wheel 13, 14, 15, 16, or the loads on the brake devices 7, 8, 9, 10 of each wheel 13, 14, 15, 16 are different. Any motor or any brake device with a high load will experience a significant increase in temperature, and its output or operation will be more likely to be limited. Alternatively, the load on the actuator (electric motor) used in the steering device will be higher when the vehicle Ve runs on a winding road in a mountain area or a road with frequent corners, for example, compared to when the vehicle Ve runs straight. As shown in Figure 1 of JP 2019-108104 A mentioned above, if there are two sets of steering devices separated into front and rear, there will be a difference in the load on each of the actuators (electric motors) in the two sets of steering devices, which will likely result in restrictions on the output or operation of one of the actuators (electric motors).

In this way, if the output or operation of any one or some of the actuators is restricted, the balance of the driving force, braking force, etc. of each wheel 13, 14, 15, 16 may be lost, and the vehicle behavior may become unstable. Therefore, in the vehicle control device according to the embodiment of the present invention, when the output or operation of any one or some of the actuators is restricted, the output or operation of the other actuators that are not restricted are also restricted. An example of the control executed by the controller 12 for this purpose is shown in the flowchart of FIG. 3.

The flowchart in Figure 3 shows an example of control in which a limit is imposed on the control target value of the driving force or braking force (forward and backward forces) acting on each wheel 13, 14, 15, 16 when a limit is imposed on any one of the four wheels 13, 14, 15, 16. First, in step S1, the target values (F_fl, F_fr, F_rl, F_rr) of the driving force and braking force to be generated at each wheel 13, 14, 15, 16 are calculated from the input value (Fx) of the force acting on the vehicle Ve and the input values (Mx, My, Mz) of the moment acting on the vehicle Ve. As shown in Figure 4(a), the input value Fx is the force in the forward and backward directions acting on the vehicle Ve (forward and backward forces). Furthermore, the input value Mx is the moment in the roll direction (roll moment) acting on the vehicle Ve, the input value My is the moment in the pitch direction (pitch moment) acting on the vehicle Ve, and the input value Mz is the moment in the yawing direction (yaw moment) acting on the vehicle Ve.

The target values F_fl, F_fr, F_rl, and F_rr of the driving force and braking force can be calculated by the same method as in the past or based on the same idea as in the past. For example, the target values F_fl, F_fr, F_rl, and F_rr of the driving force and braking force can be calculated from a determinant that expresses the relationship between the input value and the target value of the driving force and braking force at each wheel 13, 14, 15, and 16 as shown in the following formula (1) by using the inverse matrix of the determinant shown in formula (1) as shown in the following formula (2).


The applicant of the present application has disclosed in detail the calculation method for calculating the target values F_fl, F_fr, F_rl, F_rr of the driving forces and braking forces as described above in the specification of Patent Document 1 mentioned above.

Next, in step S2, it is determined whether any of the calculated driving force and braking force target values F_fl, F_fr, F_rl, F_rr is at the upper or lower limit. Specifically, it is determined whether any of the driving force and braking force target values F_fl, F_fr, F_rl, F_rr is equal to or greater than the upper limit of a predetermined target value, or is smaller than the lower limit of a predetermined target value.

If the result of step S2 is negative because all of the target values F_fl, F_fr, F_rl, and F_rr of the driving and braking forces are smaller than the upper limit of the target values and all of the target values F_fl, F_fr, F_rl, and F_rr of the driving and braking forces are equal to or greater than the lower limit of the target values, i.e., none of the calculated target values F_fl, F_fr, F_rl, and F_rr of the driving and braking forces hit the upper or lower limit, proceed to step S3.

In step S3, the calculated driving force and braking force target values F_fl, F_fr, F_rl, and F_rr are output as control target values. Therefore, the vehicle Ve is controlled so that each wheel 13, 14, 15, and 16 generates the driving force and braking force target values F_fl, F_fr, F_rl, and F_rr, respectively. After that, the routine shown in the flowchart of FIG. 3 is temporarily terminated.

On the other hand, if the answer to step S2 above is YES because any of the target values F_fl, F_fr, F_rl, F_rr of the driving force and braking force is equal to or greater than the upper limit of the target value, or any of the target values F_fl, F_fr, F_rl, F_rr of the driving force and braking force is smaller than the lower limit of the target value, i.e., any of the calculated target values F_fl, F_fr, F_rl, F_rr of the driving force and braking force hits the upper or lower limit, the process proceeds to step S4.

In step S4, the target values F_fl, F_fr, F_rl, and F_rr of the driving force and braking force are each corrected. That is, depending on the correction amount (correction coefficient, limit amount) of any of the target values F_fl, F_fr, F_rl, and F_rr of the driving force and braking force that is limited by being equal to or greater than the upper limit of the target value or smaller than the lower limit of the target value, the other target values that are not limited are also corrected by the same level of correction amount (correction coefficient, limit amount).

Specifically, the target value F_fl of the driving force and braking force for the left front wheel 13 is set as follows:
F_fl＝F_fl_Min≦Previous_F_fl＋ΔF_fl×β_fl＜F_fl_Max
Here, F_fl_Min is the lower limit of the target value F_fl of the driving force and braking force for the left front wheel 13, and F_fl_Max is the upper limit of the target value F_fl of the driving force and braking force for the left front wheel 13. The lower limit F_fl_Min and the upper limit F_fl_Max are set in advance based on the results of, for example, a running experiment using an actual vehicle or a simulation. ΔF_fl is the difference between the target value F_fl calculated in the current routine and the target value F_fl calculated in the previous routine. β_fl is a correction coefficient for the target value F_fl of the driving force and braking force for the left front wheel 13. This correction coefficient β_fl is a value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the limited state. For example, a value that is close to the limit value (coefficient) of any of the target values in the limited state is set as the correction coefficient β_fl.

Similarly, the target value F_fr of the driving force and braking force for the right front wheel 14 is
F_fr＝F_fr_Min≦Previous_F_fr＋ΔF_fr×β_fr＜F_fr_Max
Here, F_fr_Min is the lower limit of the target value F_fr of the driving force and braking force for the right front wheel 14, and F_fr_Max is the upper limit of the target value F_fr of the driving force and braking force for the right front wheel 14. The lower limit F_fr_Min and the upper limit F_fr_Max are set in advance based on the results of, for example, a running experiment using an actual vehicle or a simulation. ΔF_fr is the difference between the target value F_fr calculated in the current routine and the target value F_fr calculated in the previous routine. β_fr is a correction coefficient for the target value F_fr of the driving force and braking force for the right front wheel 14. This correction coefficient β_fr is a value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the limited state. For example, a value that is close to the limit value (coefficient) of any of the target values in the limited state is set as the correction coefficient β_fr.

Similarly, the target value F_rl of the driving force and braking force for the left rear wheel 15 is
F_rl＝F_rl_Min≦Previous_F_rl＋ΔF_rl×β_rl＜F_rl_Max
Here, F_rl_Min is the lower limit of the target value F_rl of the driving force and braking force for the left rear wheel 15, and F_rl_Max is the upper limit of the target value F_rl of the driving force and braking force for the left rear wheel 15. The lower limit F_rl_Min and the upper limit F_rl_Max are set in advance based on the results of, for example, a running experiment using an actual vehicle or a simulation. ΔF_rl is the difference between the target value F_rl calculated in the current routine and the target value F_rl calculated in the previous routine. β_rl is a correction coefficient for the target value F_rl of the driving force and braking force for the left rear wheel 15. This correction coefficient β_fr is a numerical value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the limited state. For example, a numerical value that is close to the limit value (coefficient) of any of the target values in the limited state is set as the correction coefficient β_rl.

Similarly, the target value F_rr of the driving force and braking force for the right rear wheel 16 is
F_rr＝F_rr_Min≦Previous_F_rr＋ΔF_rr×β_rr＜F_rr_Max
Here, F_rr_Min is the lower limit of the target value F_rr of the driving force and braking force for the right rear wheel 16, and F_rr_Max is the upper limit of the target value F_rr of the driving force and braking force for the right rear wheel 16. The lower limit F_rr_Min and the upper limit F_rr_Max are set in advance based on the results of, for example, a running experiment using an actual vehicle or a simulation. ΔF_rr is the difference between the target value F_rr calculated in the current routine and the target value F_rr calculated in the previous routine. β_rr is a correction coefficient for the target value F_rr of the driving force and braking force for the right rear wheel 16. This correction coefficient β_rr is a value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the limited state. For example, a value that is close to the limit value (coefficient) of any of the target values in the limited state is set as the correction coefficient β_rr.

The above correction coefficients β_fl, β_fr, β_rl, and β_rr may be changed according to the driving state and driving environment of the vehicle Ve. For example, when the vehicle Ve is driven in the danger avoidance mode, if the driving force and braking force of one of the wheels are limited, changing the driving force and braking force of the other wheels may cause an unstable state. In such a case, the correction coefficients β_fl, β_fr, β_rl, and β_rr are all set to "0". Also, when the vehicle Ve is accelerating in a straight line, for example, if the target value F_fl of the driving force and braking force for the left front wheel 13 reaches the upper limit value and a limit is imposed, it is given priority to prevent an imbalance in the driving force and braking force for the left and right front wheels 13 and 14, but it is not essential to impose a limit on the rear wheels 15 and 16. Therefore, in such a case, for example, the correction coefficient β_fr for the right front wheel 14 may be set to "0" (i.e., the driving force and braking force for the right front wheel 14 are matched to the driving force and braking force for the left front wheel 13), and the correction coefficient β_rl for the left rear wheel 15 and the correction coefficient β_rr for the right rear wheel 16 may both be set to "1.0" (i.e., the target values F_rl, F_rr of the driving force and braking force for the left and right rear wheels 15, 16 are not corrected).

Furthermore, when the vehicle Ve is traveling at high speed, imposing a restriction with a large correction value can easily upset the balance of the vehicle behavior. Therefore, as shown in Table 1 (map) below, the correction coefficients β_** (i.e., each of the correction coefficients β_fl, β_fr, β_rl, β_rr) may be set so that the higher the vehicle speed, the smaller the value.

When the target values F_fl, F_fr, F_rl, F_rr of the driving force and braking force for each wheel 13, 14, 15, 16 are corrected in step S4 as described above, the process proceeds to step S3, where the corrected target values F_fl, F_fr, F_rl, F_rr of the driving force and braking force are output as control target values. Therefore, in this case, the vehicle Ve is controlled so that the corrected, i.e., limited, target values F_fl, F_fr, F_rl, F_rr of the driving force and braking force are generated in each wheel 13, 14, 15, 16. Then, the routine shown in the flowchart of FIG. 3 is temporarily terminated.

The flowchart in FIG. 5 shows an example of control in which, when a restriction is imposed on any one of the four wheels 13, 14, 15, 16, the control input value of the driving force or braking force (forward and backward forces) acting on each wheel 13, 14, 15, 16 and the control input value of the moment acting on the vehicle Ve are restricted. Note that in the control example shown in the flowchart in FIG. 3 or the previously mentioned flowchart, steps having the same control content as those shown in the flowchart in FIG. 3 or the previously mentioned flowchart are given the same step numbers as those used in the flowchart in FIG. 3 or the previously mentioned flowchart.

In the control example shown in the flowchart of FIG. 5, if the answer to step S2 is YES because any of the target values F_fl, F_fr, F_rl, F_rr of the driving force and braking force is equal to or greater than the upper limit of the target value, or any of the target values F_fl, F_fr, F_rl, F_rr of the driving force and braking force is smaller than the lower limit of the target value, i.e., any of the calculated target values F_fl, F_fr, F_rl, F_rr of the driving force and braking force hits the upper or lower limit, the process proceeds to step S11.

In step S11, the input values (Fx, Mx, My, Mz) used when calculating the target values F_fl, F_fr, F_rl, F_rr of the driving force and braking force for each wheel 13, 14, 15, 16, i.e., the input value (Fx) of the force acting on the vehicle Ve and the input value (Mx, My, Mz) of the moment acting on the vehicle Ve, are each corrected.

Specifically, an input value Fx of a force in the front-rear direction (front-rear force) acting on the vehicle Ve is expressed as follows:
Fx = previous_Fx + ΔFx × γ_Fx
Here, ΔFx is the difference between the longitudinal force input value Fx calculated in the current routine and the longitudinal force input value Fx calculated in the previous routine. And, γ_Fx is a correction coefficient for the longitudinal force input value Fx. This correction coefficient γ_Fx is a numerical value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the restricted state. For example, a numerical value approximating the limit value (coefficient) of any of the target values in the restricted state is set as the correction coefficient γ_Fx.

Similarly, the input value Mx of the roll moment acting on the vehicle Ve is expressed as follows:
Mx = previous_Mx + ΔMx × γ_Mx
Here, ΔMx is the difference between the input value Mx of the roll moment calculated in the current routine and the input value Mx of the roll moment calculated in the previous routine. And, γ_Mx is a correction coefficient for the input value Mx of the roll moment. This correction coefficient γ_Mx is a numerical value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the restricted state. For example, a numerical value approximating the limit value (coefficient) of any of the target values in the restricted state is set as the correction coefficient γ_Mx.

Similarly, the input value My of the pitch moment acting on the vehicle Ve is expressed as follows:
My = previous_My + ΔMy × γ_My
Here, ΔMy is the difference between the pitch moment input value My calculated in the current routine and the pitch moment input value My calculated in the previous routine. And γ_My is a correction coefficient for the pitch moment input value My. This correction coefficient γ_My is a numerical value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the limited state. For example, a numerical value approximating the limit value (coefficient) of any of the target values in the limited state is set as the correction coefficient γ_My.

Similarly, the input value Mz of the yaw moment acting on the vehicle Ve is expressed as follows:
Mz = previous_Mz + ΔMz × γ_Mz
Here, ΔMz is the difference between the input value Mz of the yaw moment calculated in the current routine and the input value Mz of the yaw moment calculated in the previous routine. And, γ_Mz is a correction coefficient for the input value Mz of the yaw moment. This correction coefficient γ_Mz is a numerical value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the restricted state. For example, a numerical value approximating the limit value (coefficient) of any of the target values in the restricted state is set as the correction coefficient γ_Mz.

The above correction coefficients γ_Fx, γ_Mx, γ_My, and γ_Mz may be changed depending on the driving state and driving environment of the vehicle Ve. For example, when the vehicle Ve is being driven in the danger avoidance mode and the driving force and braking force of any wheel are restricted, changing the driving force and braking force of the other wheels may result in an unstable state. In such a case, the correction coefficients γ_Fx, γ_Mx, γ_My, and γ_Mz are all set to "0."

In addition, when the vehicle Ve is traveling at high speed, imposing a restriction with a large correction value can easily upset the balance of the vehicle behavior. Therefore, as shown in Table 2 (map) below, the correction coefficients γ_** (i.e., each of the correction coefficients γ_Fx, γ_Mx, γ_My, γ_Mz) may be set so that the higher the vehicle speed, the smaller the value.

Next, in step S12, target values F_fl, F_fr, F_rl, and F_rr of the driving and braking forces for each wheel 13, 14, 15, and 16 are calculated based on the corrected input values Fx, Mx, My, and Mz. Here, new target values F_fl, F_fr, F_rl, and F_rr are calculated using the same control content as in step S1 in the flowchart of FIG. 3 described above.

As described above, when the target values F_fl, F_fr, F_rl, and F_rr of the driving force and the braking force for each wheel 13, 14, 15, and 16 are calculated in step S12, the process proceeds to step S3, and the newly calculated target values F_fl, F_fr, F_rl, and F_rr of the driving force and the braking force are output as control target values. Therefore, in this case, the vehicle Ve is controlled so that each wheel 13, 14, 15, and 16 generates the target values F_fl, F_fr, F_rl, and F_rr of the driving force and the braking force calculated based on the corrected, i.e., limited, input values Fx, Mx, My, and Mz. Then, the routine shown in the flowchart of FIG. 5 is temporarily terminated.

The flowchart in Figure 6 shows an example of control in which restrictions are imposed on the control target values of the triaxial forces acting on each wheel 13, 14, 15, 16 when restrictions are imposed on any one of the four wheels 13, 14, 15, 16. First, in step S21, the target values (Fx_**, Fy_**, Fz_**) of the triaxial forces to be generated at each wheel 13, 14, 15, 16 are calculated from the input values (Fx, Fy, Fz, Mx, My, Mz) of the forces and moments acting on the vehicle Ve.

As shown in FIG. 4(a), the input value Fx is a force in the front-rear direction (x-axis direction) acting on the center of gravity Cg of the vehicle Ve. The input value Fy is a force in the lateral direction (y-axis direction) acting on the center of gravity Cg of the vehicle Ve. The input value Fz is a force in the up-down direction (z-axis direction) acting on the center of gravity Cg of the vehicle Ve. On the other hand, the input value Mx is a moment in the roll direction acting on the vehicle Ve. The input value My is a moment in the pitch direction acting on the vehicle Ve. The input value Mz is a moment in the yawing direction acting on the vehicle Ve.

As shown in FIG. 4B, the target values Fx_** (i.e., target values Fx_fl, Fx_fr, Fx_rl, Fx_rr), Fy_** (i.e., target values Fy_fl, Fy_fr, Fy_rl, Fy_rr), and Fz_** (i.e., target values Fz_fl, Fz_fr, Fz_rl, Fz_rr) of the forces in the three axes acting on each wheel 13, 14, 15, 16 can be calculated using a method similar to that of the past or based on a concept similar to that of the past. That is, the target values Fx_**, Fy_**, Fz_** can be calculated in the same manner as step S1 in the flowchart of FIG. 3 described above and in the same manner as the calculation method disclosed in the specification of the above-mentioned Patent Document 1.

Next, in step S22, it is determined whether any of the calculated target values Fx_**, Fy_**, Fz_** falls within the upper or lower limit. Specifically, it is determined whether any of the target values Fx_**, Fy_**, Fz_** is equal to or greater than the upper limit of a predetermined target value, or whether it is smaller than the lower limit of a predetermined target value.

If the result of step S22 is negative because each of the target values Fx_**, Fy_**, Fz_** is smaller than the upper limit of the target value and each of the target values Fx_**, Fy_**, Fz_** is equal to or greater than the lower limit of the target value, i.e., none of the calculated target values Fx_**, Fy_**, Fz_** hits the upper or lower limit, proceed to step S23.

In step S23, the calculated target values Fx_**, Fy_**, Fz_** are output as control target values. Therefore, the vehicle Ve is controlled so that each of the wheels 13, 14, 15, and 16 generates the target values Fx_**, Fy_**, and Fz_** of the forces in the three axial directions. After that, the routine shown in the flowchart of FIG. 6 is temporarily terminated.

On the other hand, if the answer to step S22 is YES because any of the target values Fx_**, Fy_**, Fz_** is equal to or greater than the upper limit of the target value, or any of the target values Fx_**, Fy_**, Fz_** is smaller than the lower limit of the target value, i.e., any of the calculated target values Fx_**, Fy_**, Fz_** hits the upper or lower limit, the process proceeds to step S24.

In step S24, the target values Fx_**, Fy_**, and Fz_** of the forces in the three axial directions are corrected. That is, depending on the correction amount (correction coefficient, limit amount) of any of the target values Fx_**, Fy_**, and Fz_** that is in a state of being limited by being equal to or greater than the upper limit value of the target value or smaller than the lower limit value of the target value, the other target values that are not in a state of being limited are also corrected by the same level of correction amount (correction coefficient, limit amount).

Specifically, the target value Fx_** of the force in the front-rear direction (front-rear force) on each of the wheels 13, 14, 15, and 16 is expressed as follows:
Fx_**＝Fx_**_Min≦Previous_Fx_**＋ΔFx_**×βx_**＜Fx_**_Max
Here, Fx_**_Min is the lower limit of the target value Fx_** of the force in the longitudinal direction for each wheel 13, 14, 15, 16, and Fx_**_Max is the upper limit of the target value Fx_** of the force in the longitudinal direction for each wheel 13, 14, 15, 16. The lower limit Fx_**_Min and the upper limit Fx_**_Max are set in advance based on the results of, for example, a running experiment using an actual vehicle or a simulation. Also, ΔFx_** is the difference between the target value Fx_** calculated in the current routine and the target value Fx_** calculated in the previous routine. And, βx_** is a correction coefficient for the target value Fx_** of the force in the longitudinal direction for each wheel 13, 14, 15, 16. This correction coefficient βx_** is a numerical value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the limited state. For example, a numerical value that is close to the limit value (coefficient) of any of the target values in the limited state is set as the correction coefficient βx_**.

Similarly, the target value Fy_** of the lateral force (lateral force) for each of the wheels 13, 14, 15, and 16 is expressed as
Fy_**＝Fy_**_Min≦Previous_Fy_**＋ΔFy_**×βy_**＜Fy_**_Max
Here, Fy_**_Min is the lower limit of the target value Fy_** of the lateral force for each wheel 13, 14, 15, 16, and Fy_**_Max is the upper limit of the target value Fy_** of the lateral force for each wheel 13, 14, 15, 16. The lower limit Fy_**_Min and the upper limit Fy_**_Max are set in advance based on the results of, for example, a running experiment using an actual vehicle or a simulation. ΔFy_** is the difference between the target value Fy_** calculated in the current routine and the target value Fy_** calculated in the previous routine. βy_** is a correction coefficient for the target value Fy_** of the lateral force for each wheel 13, 14, 15, 16. This correction coefficient βy_** is a value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the limited state. For example, a numerical value that is close to the limit value (coefficient) of any of the target values in the limited state is set as the correction coefficient βy_**.

Similarly, the target value Fz_** of the vertical force (ground load) on each of the wheels 13, 14, 15, and 16 is expressed as follows:
Fz_**＝Fz_**_Min≦Previous_Fz_**＋ΔFz_**×βz_**＜Fz_**_Max
Here, Fz_**_Min is the lower limit of the target value Fz_** of the vertical force for each wheel 13, 14, 15, 16, and Fz_**_Max is the upper limit of the target value Fz_** of the vertical force for each wheel 13, 14, 15, 16. The lower limit Fz_**_Min and the upper limit Fz_**_Max are set in advance based on the results of, for example, a running experiment using an actual vehicle or a simulation. Also, ΔFz_** is the difference between the target value Fz_** calculated in the current routine and the target value Fz_** calculated in the previous routine. And, βz_** is a correction coefficient for the target value Fz_** of the vertical force for each wheel 13, 14, 15, 16. This correction coefficient βz_** is a value in the range from 0 to 1.0, and is set according to the limit level of any of the target values in the limited state. For example, a numerical value that is close to the limit value (coefficient) of any of the target values in the limited state is set as the correction coefficient βz_**.

The above correction coefficients βx_**, βy_**, and βz_** may be changed according to the driving state and driving environment of the vehicle Ve. For example, when the vehicle Ve is driven in the danger avoidance mode, if the driving force and braking force of one of the wheels are limited, changing the driving force and braking force of the other wheels may result in an unstable state. In such a case, the correction coefficients βx_**, βy_**, and βz_** are all set to "0". Also, when the vehicle Ve is accelerating in a straight line, for example, if the target value Fx_fl of the driving force and braking force for the left front wheel 13 reaches the upper limit value and a limit is imposed, it is given priority to prevent an imbalance in the driving force and braking force for the left and right front wheels 13 and 14, but it is not essential to limit the driving force and braking force or the steering angle of the rear wheels 15 and 16. Therefore, in such a case, for example, the correction coefficient βx_fr for the right front wheel 14 may be set to "0" (i.e., the driving force and braking force for the right front wheel 14 are matched to the driving force and braking force for the left front wheel 13), and the other correction coefficients βx_rl, βx_rr, βy_**, and βz_** may all be set to "1.0" (i.e., the target values Fx_rl, Fx_rr of the longitudinal forces for the left and right rear wheels 15, 16, and the target values Fy_fl, Fy_fr, Fy_rl, Fy_rr, Fz_fl, Fz_fr, Fz_rl, and Fz_rr of the lateral and vertical forces for each wheel 13, 14, 15, 16 are not corrected).

Furthermore, when the vehicle Ve is traveling at high speed, imposing restrictions with large correction values can easily upset the balance of the vehicle behavior. Therefore, as shown in Table 3 (map) below, the correction coefficients βx_**, βy_**, and βz_** may be set so that the higher the vehicle speed, the smaller the values become.

When the target values Fx_**, Fy_**, Fz_** of the forces in the three axes directions for each wheel 13, 14, 15, 16 are corrected in step S24 as described above, the process proceeds to step S23, where the corrected target values Fx_**, Fy_**, Fz_** are output as control target values. Therefore, in this case, the vehicle Ve is controlled so that the wheels 13, 14, 15, 16 generate corrected, i.e., limited, target values Fx_**, Fy_**, Fz_** of the forces in the three axes directions. Then, the routine shown in the flowchart of FIG. 6 is temporarily terminated.

The flowchart in Figure 7 shows an example of control that places restrictions on the control input values of the triaxial forces acting on each wheel 13, 14, 15, 16 and the control input value of the moment acting on the vehicle Ve when restrictions are placed on any one of the four wheels 13, 14, 15, 16.

In the control example shown in the flowchart of FIG. 7, if the answer to step S22 is affirmative because any of the target values Fx_**, Fy_**, Fz_** of the forces in the three axes acting on each wheel 13, 14, 15, 16 is equal to or greater than the upper limit of the target value, or any of the target values Fx_**, Fy_**, Fz_** is smaller than the lower limit of the target value, i.e., any of the calculated target values Fx_**, Fy_**, Fz_** hits the upper or lower limit, the process proceeds to step S31.

In step S31, the input values Fx, Fy, Fz, Mx, My, and Mz used when calculating the target values Fx_**, Fy_**, and Fz_** of the three-axial forces for each wheel 13, 14, 15, and 16 are corrected.

Specifically, the input value Fx of the force acting on the vehicle Ve in the forward/rearward direction is expressed as follows:
Fx = previous_Fx + ΔFx × γ_Fx
Here, ΔFx is the difference between the input value Fx of the force in the front-rear direction calculated in the current routine and the input value Fx of the force in the front-rear direction calculated in the previous routine. And, γ_Fx is a correction coefficient for the input value Fx of the force in the front-rear direction. This correction coefficient γ_Fx is a numerical value in the range from 0 to 1.0, and is set according to the limit level of any of the target values in the restricted state. For example, a numerical value that is close to the limit value (coefficient) of any of the target values in the restricted state is set as the correction coefficient γ_Fx.

Similarly, the input value Fy of the lateral force acting on the vehicle Ve is expressed as follows:
Fy = previous_Fy + ΔFy × γ_Fy
Here, ΔFy is the difference between the lateral force input value Fy calculated in the current routine and the lateral force input value Fy calculated in the previous routine. And, γ_Fy is a correction coefficient for the lateral force input value Fy. This correction coefficient γ_Fy is a numerical value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the restricted state. For example, a numerical value approximating the limit value (coefficient) of any of the target values in the restricted state is set as the correction coefficient γ_Fy.

Similarly, the input value Fz of the vertical force acting on the vehicle Ve is expressed as follows:
Fz = previous_Fz + ΔFz × γ_Fz
Here, ΔFz is the difference between the vertical force input value Fz calculated in the current routine and the vertical force input value Fz calculated in the previous routine. And, γ_Fz is a correction coefficient for the vertical force input value Fz. This correction coefficient γ_Fz is a numerical value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the restricted state. For example, a numerical value that is close to the limit value (coefficient) of any of the target values in the restricted state is set as the correction coefficient γ_Fz.

Similarly, the input value Mx of the roll moment acting on the vehicle Ve is expressed as follows:
Mx = previous_Mx + ΔMx × γ_Mx
Here, ΔMx is the difference between the input value Mx of the roll moment calculated in the current routine and the input value Mx of the roll moment calculated in the previous routine. And, γ_Mx is a correction coefficient for the input value Mx of the roll moment. This correction coefficient γ_Mx is a numerical value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the restricted state. For example, a numerical value approximating the limit value (coefficient) of any of the target values in the restricted state is set as the correction coefficient γ_Mx.

Similarly, the input value My of the pitch moment acting on the vehicle Ve is expressed as follows:
My = previous_My + ΔMy × γ_My
Here, ΔMy is the difference between the pitch moment input value My calculated in the current routine and the pitch moment input value My calculated in the previous routine. And γ_My is a correction coefficient for the pitch moment input value My. This correction coefficient γ_My is a numerical value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the limited state. For example, a numerical value approximating the limit value (coefficient) of any of the target values in the limited state is set as the correction coefficient γ_My.

Similarly, the input value Mz of the yaw moment acting on the vehicle Ve is expressed as follows:
Mz = previous_Mz + ΔMz × γ_Mz
Here, ΔMz is the difference between the input value Mz of the yaw moment calculated in the current routine and the input value Mz of the yaw moment calculated in the previous routine. And, γ_Mz is a correction coefficient for the input value Mz of the yaw moment. This correction coefficient γ_Mz is a numerical value ranging from 0 to 1.0, and is set according to the limit level of any of the target values in the restricted state. For example, a numerical value approximating the limit value (coefficient) of any of the target values in the restricted state is set as the correction coefficient γ_Mz.

The above correction coefficients γ_Fx, γ_Fy, γ_Fz, γ_Mx, γ_My, and γ_Mz may be changed according to the driving state and driving environment of the vehicle Ve. For example, when the vehicle Ve is being driven in the danger avoidance mode and the driving force and braking force of any wheel are restricted, changing the driving force and braking force of the other wheels may result in an unstable state. In such a case, the correction coefficients γ_Fx, γ_Fy, γ_Fz, γ_Mx, γ_My, and γ_Mz are all set to "0."

In addition, when the vehicle Ve is traveling at high speed, imposing a restriction with a large correction value can easily upset the balance of the vehicle behavior. Therefore, as shown in Table 4 (map) below, the correction coefficients γ_* (i.e., each of the correction coefficients γ_Fx, γ_Fy, γ_Fz, γ_Mx, γ_My, γ_Mz) may be set so that the higher the vehicle speed, the smaller the value.

Next, in step S32, the target values Fx_**, Fy_**, Fz_** of the forces in the three axes for each wheel 13, 14, 15, 16 are calculated based on the corrected input values Fx, Fy, Fz, Mx, My, Mz. Here, the target values Fx_**, Fy_**, Fz_** are newly calculated using the same control content as in step S1 in the flowchart of FIG. 3 described above.

As described above, when the target values Fx_**, Fy_**, Fz_** of the force in the three axial directions for each wheel 13, 14, 15, 16 are calculated in step S32, the process proceeds to step S23, where the newly calculated target values Fx_**, Fy_**, Fz_** of the force in the three axial directions are output as control target values. Therefore, in this case, the vehicle Ve is controlled so that the target values Fx_**, Fy_**, Fz_** of the force in the three axial directions are generated for each wheel 13, 14, 15, 16, which are calculated based on the corrected, i.e., limited, input values Fx, Fy, Fz, Mx, My, Mz. Then, the routine shown in the flowchart of FIG. 7 is temporarily terminated.

The flowchart in FIG. 8 shows an example of control in which, when a restriction is imposed on one of the two power supplies 5, 6 (front and rear), a restriction is imposed on the motor connected to the other power supply (battery) to maintain the torque distribution of the front and rear wheels 13, 14, 15, 16. First, in step S41, it is determined whether the Fr battery temperature is equal to or higher than a predetermined value A, that is, whether the temperature (battery temperature) of the battery in the first power supply 5 on the front wheel 13, 14 side is equal to or higher than a predetermined value A. The predetermined value A is a threshold value for determining whether the output of the first power supply 5 is in a limited (or restricted) state, and is set in advance based on the results of, for example, driving experiments using an actual vehicle or simulations. When the temperature of the battery in the first power supply 5 is equal to or higher than the predetermined value A, it is determined that the output of the first power supply 5 is in a limited (or restricted) state.

If the battery temperature in the first power supply device 5 on the front wheel 13, 14 side is lower than the predetermined value A and therefore the result of step S41 is negative, i.e., if it is determined that the output of the first power supply device 5 is not in a limited (or restricted) state, the process proceeds to step S42.

In step S42, it is determined whether the Rr battery temperature is equal to or higher than a predetermined value B, i.e., whether the temperature of the battery in the second power supply device 6 on the rear wheel 15, 16 side is equal to or higher than a predetermined value B. The predetermined value B is a threshold value for determining whether the output of the second power supply device 6 is in a limited (or restricted) state, and is set in advance based on the results of, for example, driving experiments using an actual vehicle or simulations. If the temperature of the battery in the second power supply device 6 is equal to or higher than the predetermined value B, it is determined that the output of the second power supply device 6 is in a limited (or restricted) state.

If the battery temperature in the second power supply device 6 on the rear wheel 15, 16 side is lower than the predetermined value B and thus the result of step S42 is negative, i.e., if it is determined that the output of the second power supply device 6 is not in a state in which it is limited (or has not been limited), the routine shown in the flowchart of FIG. 8 is temporarily terminated without executing any further control.

On the other hand, if the battery temperature in the first power supply device 5 on the front wheel 13, 14 side is equal to or higher than the predetermined value A, and thus the answer in step S41 is affirmative, i.e., if it is determined that the output of the first power supply device 5 is in a limited (or has been limited) state, the process proceeds to step S43.

In step S43, the Fr motor torque upper limit is calculated. That is, the upper limit of the output torque of the first motor 1 on the front wheels 13, 14 side, which is connected to the first power supply 5 in an output-limited (or restricted) state, is calculated. For example, the upper limit of the output torque of the first motor 1 can be obtained from a map set based on the "battery temperature-torque upper limit characteristic" as shown in FIG. 9.

In step S44, a front/rear distribution request value is calculated. The front/rear distribution request value determines the distribution ratio between the drive torque on the front wheels 13, 14 side and the drive torque on the rear wheels 15, 16 side, and is the ratio between the output torque (Fr motor torque) of the first motor 1 on the front wheels 13, 14 side and the output torque (Rr motor torque) of the second motor 2 on the rear wheels 15, 16 side, which is calculated in the current routine. In other words, the front/rear distribution request value is
The front/rear distribution requirement value is calculated as Fr motor torque/Rr motor torque.

In step S45, an Rr motor torque correction value is calculated. That is, a correction value (or limit value) for the output torque of the second motor 2 on the rear wheels 15, 16 side, which is connected to the second power supply device 6 whose output is not limited (or restricted), is calculated. Specifically, the Rr motor torque correction value is calculated from the Fr motor torque upper limit value and the front/rear distribution request value calculated in each step above, as follows:
The Rr motor torque correction value is calculated as follows: Rr motor torque upper limit value / front/rear distribution request value. At the same time, the output torque of the second motor 2 is corrected based on the calculated Rr motor torque correction value. In other words, the output of the second motor 2 is limited. Then, the routine shown in the flowchart of FIG. 8 is temporarily terminated.

On the other hand, if the battery temperature (battery temperature) of the second power supply device 6 on the rear wheel 15, 16 side is equal to or higher than the predetermined value B, and thus the answer to the above-mentioned step S42 is affirmative, that is, if it is determined that the output of the second power supply device 6 is in a limited (or has been limited) state, the process proceeds to step S46.

In step S46, the Rr motor torque upper limit is calculated. That is, the upper limit of the output torque of the second motor 2 on the rear wheels 15, 16 side, which is connected to the second power supply 6 in an output-limited (or restricted) state, is calculated. For example, the upper limit of the output torque of the second motor 2 can be found from a map set based on the "battery temperature-torque upper limit characteristic" as shown in FIG. 9.

In step S47, a front/rear distribution request value is calculated. This front/rear distribution request value is the same as the front/rear distribution request value calculated in the above-mentioned step S43. Therefore, the front/rear distribution request value is expressed as follows:
The front/rear distribution requirement value is calculated as Fr motor torque/Rr motor torque.

In step S48, an Fr motor torque correction value is calculated. That is, a correction value (or limit value) for the output torque of the first motor 1 on the front wheels 13, 14 side, which is connected to the first power supply device 5 whose output is not limited (or restricted), is calculated. Specifically, the Fr motor torque correction value is calculated from the Rr motor torque upper limit value and the front/rear distribution request value calculated in the above steps as follows:
The Fr motor torque correction value is calculated as follows: Fr motor torque upper limit value x front/rear distribution request value. At the same time, the output torque of the first motor 1 is corrected based on the calculated Fr motor torque correction value. In other words, the output of the first motor 1 is limited. Then, the routine shown in the flowchart of FIG. 8 is temporarily terminated.

As described above, when one of the two power supplies 5, 6 (front and rear) is restricted, the output of the motor connected to the other power supply (battery) is restricted, thereby maintaining the torque distribution of the front and rear wheels 13, 14, 15, 16. For example, as shown in FIG. 10, when the ratio of the driving force of the front wheels 13, 14 (Fr) to the driving force of the rear wheels 15, 16 (Rr), i.e., the front/rear distribution, is "40:60", if the ratio of the driving force of the rear wheels 15, 16 (Rr) is limited to "40", the ratio of the driving force of the front wheels 13, 14 (Fr) is limited to "26". As a result, although the total output of the actuator as a whole, including the first motor 1 and the second motor 2, is reduced, it is possible to avoid or suppress a situation in which the balance of the driving forces between the front wheels 13, 14 and the rear wheels 15, 16 is lost, resulting in unstable vehicle behavior.

The flowcharts in Figures 11 and 12 show an example of control in which, when one of the two power supplies (batteries) 5, 6 (front and rear) is restricted while the vehicle Ve is turning or steering at a predetermined steering angle or more, the control content for the motor connected to the other power supply (battery) is corrected to maintain the yaw rate acting on the body of the vehicle Ve, as shown in Figure 13. First, in step S51 shown in the flowchart in Figure 11, the yaw rate value α (target value) is detected. In order to control the vehicle Ve to maintain its yaw rate, the yaw rate value α is detected or calculated as the target value or reference value for control.

In step S52, it is determined whether the Fr battery temperature is equal to or higher than a predetermined value A, i.e., whether the temperature of the battery (battery temperature) in the first power supply device 5 on the front wheel 13, 14 side is equal to or higher than a predetermined value A. As with step S41 in the flowchart of FIG. 8 described above, the predetermined value A is a threshold value for determining whether the output of the first power supply device 5 is in a limited (or restricted) state. If the temperature of the battery in the first power supply device 5 is equal to or higher than the predetermined value A, it is determined that the output of the first power supply device 5 is in a limited (or restricted) state.

If the battery temperature in the first power supply device 5 on the front wheel 13, 14 side is lower than the predetermined value A and therefore the result of step S52 is negative, i.e., if it is determined that the output of the first power supply device 5 is not in a state in which it is limited (or has not been limited), the process proceeds to step S53.

In step S53, it is determined whether the Rr battery temperature is equal to or higher than a predetermined value B, i.e., whether the temperature of the battery (battery temperature) in the second power supply device 6 on the rear wheel 15, 16 side is equal to or higher than a predetermined value B. As with step S42 in the flowchart of FIG. 8 described above, the predetermined value B is a threshold value for determining whether the output of the second power supply device 6 is in a limited (or restricted) state. If the temperature of the battery in the second power supply device 6 is equal to or higher than the predetermined value B, it is determined that the output of the second power supply device 6 is in a limited (or restricted) state.

If the battery temperature in the second power supply device 6 on the rear wheel 15, 16 side is lower than the predetermined value B and thus the result of step S53 is negative, i.e., if it is determined that the output of the second power supply device 6 is not in a state in which it is limited (or has not been limited), the routine shown in the flowcharts of Figures 11 and 12 is temporarily terminated without executing any further control.

On the other hand, if the battery temperature in the first power supply device 5 on the front wheel 13, 14 side is equal to or higher than the predetermined value A, and thus the answer to step S52 is affirmative, i.e., if it is determined that the output of the first power supply device 5 is in a limited (or has been limited) state, the process proceeds to step S54.

In step S54, the Fr motor torque upper limit is calculated. That is, the upper limit of the output torque of the first motor 1 (on the front wheels 13, 14 side) connected to the first power supply 5, whose output is limited (or has been limited), is calculated. For example, the upper limit of the output torque of the first motor 1 can be found from a map set based on the "battery temperature-torque upper limit characteristic" as shown in FIG. 9 above.

In step S55, the Fr motor torque is subtracted by a predetermined value. That is, the output torque of the first motor 1 (on the front wheels 13, 14 side) connected to the first power supply 5, whose output is limited (or has been limited), is reduced to below the upper limit calculated in step S54 above.

In step S56, the yaw rate value β (current value) is detected. Here, the latest value (yaw rate value β) of the yaw rate of the vehicle Ve that changes as a result of the output torque of the first motor 1 being reduced to the upper limit value as described above is detected. It may be calculated as an estimate based on the output torque of the first motor 1 that is reduced.

In step S57, it is determined whether the yaw rate value β is greater than the yaw rate value α. In other words, it is determined whether the yaw rate of the vehicle Ve has increased due to a decrease in the output torque of the first motor 1 while the vehicle Ve is turning or steering.

If the answer to step S57 is affirmative because the yaw rate value β is greater than the yaw rate value α, i.e., the yaw rate of the vehicle Ve has increased, the process proceeds to step S58.

In step S58, the outer wheel torque is subtracted by a predetermined value, and the inner wheel torque is added by a predetermined value. That is, in order to maintain the increased (increasing) yaw rate at the initial yaw rate (yaw rate value α), the output torque of the wheels 13, 15 (or wheels 14, 16) that are the outer wheels of the turning vehicle Ve is reduced. At the same time, the output torque of the wheels 14, 16 (or wheels 13, 15) that are the inner wheels of the turning vehicle Ve is increased. After that, the process returns to the aforementioned step S56, and the previous control from step S56 onwards is executed.

If the yaw rate value β is equal to or less than the yaw rate value α, i.e., the yaw rate of the vehicle Ve has not increased and a negative determination is made in step S57, the process proceeds to step S59. In other words, when the output torque of the first motor 1 is reduced toward the upper limit value and the yaw rate of the vehicle Ve (yaw rate value β) increases, the control of step S58 is repeated until the increase is reduced again.

In step S59, it is determined whether the Fr motor torque has reached the upper limit. In other words, it is determined whether the output torque of the first motor 1, whose upper limit was set in step S54 above due to the first power supply device 5 being in an output-limited (or output-restricted) state, has decreased to the upper limit.

If the Fr motor torque has not yet reached the upper limit, i.e., the output torque of the first motor 1 exceeds the upper limit set in step S54, and a negative determination is made in step S59, the process returns to step S55, and the previous control from step S55 onwards is executed.

On the other hand, if the Fr motor torque has reached its upper limit, i.e., the output torque of the first motor 1 is equal to or lower than the upper limit set in step S54 above, and the result of the affirmative determination in step S59 is that the process proceeds to step S60.

In step S60, the inner and outer wheel motor torques are determined. Also, the left and right distribution of the motor torque is determined. That is, with the output torque of the first motor 1 limited to the upper limit, the output torque of the wheels 13, 15 (or wheels 14, 16) that are the outer wheels of the turning vehicle Ve, the output torque of the wheels 14, 16 (or wheels 13, 15) that are the inner wheels of the turning vehicle Ve, and the torque distribution ratio of the left and right wheels (wheels 13, 15 and wheels 14, 16) are determined. Then, each motor 1, 2 and each torque vectoring device 3, 4 are controlled based on this. Then, the routine shown in the flowchart of FIG. 11 and FIG. 12 is temporarily terminated.

On the other hand, if the battery temperature in the second power supply device 6 on the rear wheel 15, 16 side is equal to or higher than the predetermined value B and the result of the above step S53 is affirmative, that is, if it is determined that the output of the second power supply device 6 is in a limited (or has been limited) state, the process proceeds to step S61 shown in the flowchart of FIG. 12.

In step S61, the Rr motor torque upper limit is calculated. That is, the upper limit of the output torque of the second motor 2 (on the rear wheels 15, 16 side) connected to the second power supply 6, whose output is limited (or has been limited), is calculated. For example, the upper limit of the output torque of the second motor 2 can be found from a map that is set based on the "battery temperature-torque upper limit characteristic" as shown in FIG. 9 above.

In step S62, the Rr motor torque is subtracted by a predetermined value. That is, the output torque of the second motor 2 (on the rear wheels 15, 16 side) connected to the second power supply 6, whose output is limited (or has been limited), is reduced to below the upper limit calculated in step S61 above.

In step S63, the yaw rate value γ (current value) is detected. Here, the latest value (yaw rate value γ) of the yaw rate of the vehicle Ve that changes as a result of the output torque of the second motor 2 being reduced to the upper limit value as described above is detected. It may be calculated as an estimate based on the output torque of the second motor 2 that is reduced.

In step S64, it is determined whether the yaw rate value γ is smaller than the yaw rate value α. In other words, it is determined whether the yaw rate of the vehicle Ve has decreased due to a decrease in the output torque of the second motor 2 while the vehicle Ve is turning or steering.

If the answer to step S64 is affirmative because the yaw rate value γ is smaller than the yaw rate value α, i.e., the yaw rate of the vehicle Ve has decreased, the process proceeds to step S65.

In step S65, the outer wheel torque is increased by a predetermined value, and the inner wheel torque is decreased by a predetermined value. That is, in order to maintain the decreased (decreasing) yaw rate at the initial yaw rate (yaw rate value α), the output torque of the wheels 13, 15 (or wheels 14, 16) that are the outer wheels of the turning vehicle Ve is increased. At the same time, the output torque of the wheels 14, 16 (or wheels 13, 15) that are the inner wheels of the turning vehicle Ve is decreased. After that, the process returns to the aforementioned step S63, and the previous control from step S63 onwards is executed.

If the yaw rate value γ is equal to or greater than the yaw rate value α, i.e., the yaw rate of the vehicle Ve has not decreased and a negative determination is made in step S64, the process proceeds to step S66. In other words, when the yaw rate of the vehicle Ve (yaw rate value β) decreases as a result of the output torque of the second motor 2 being reduced toward the upper limit value, the control of step S65 is repeated until the amount of decrease increases again.

In step S66, it is determined whether the Rr motor torque has reached the upper limit. In other words, it is determined whether the output torque of the second motor 2, whose upper limit was set in step S61 above, has decreased to the upper limit because the second power supply 6 is in an output-limited (or output-restricted) state.

If the Fr motor torque has not yet reached the upper limit, i.e., the output torque of the second motor 2 exceeds the upper limit set in step S61, and a negative determination is made in step S66, the process returns to step S62, and the previous control from step S62 onwards is executed.

On the other hand, if the Fr motor torque has reached its upper limit, i.e., the output torque of the second motor 2 has fallen below the upper limit set in step S61, and the result of the affirmative determination in step S66 is that the process proceeds to step S67.

In step S67, the inner and outer wheel motor torques are determined. Also, the left and right distribution of the motor torque is determined. That is, with the output torque of the second motor 2 limited to the upper limit, the output torque of the wheels 13, 15 (or wheels 14, 16) that are the outer wheels of the turning vehicle Ve, the output torque of the wheels 14, 16 (or wheels 13, 15) that are the inner wheels of the turning vehicle Ve, and the torque distribution ratio of the left and right wheels (wheels 13, 15 and wheels 14, 16) are determined. Then, each motor 1, 2 and each torque vectoring device 3, 4 are controlled based on this. Then, the routine shown in the flowchart of FIG. 11 and FIG. 12 is temporarily terminated.

The flowchart in FIG. 14 shows an example of control for changing the "constraint (restriction) response mode" according to the state of the power supply device (battery) in a "state where there is little margin to the battery constraint". That is, the control shown in the flowchart in FIG. 14 is executed when the first power supply device 5 or the second power supply device 6 is in a "state where there is little margin to the battery constraint". The "state where there is little margin to the battery constraint" is a state where the temperature (battery temperature) of the battery in the first power supply device 5 has risen to a temperature at which the output of the first power supply device 5 is limited, that is, a temperature close to the above-mentioned predetermined value A, and a state where the temperature (battery temperature) of the battery in the second power supply device 6 has risen to a temperature at which the output of the second power supply device 6 is limited, that is, a temperature close to the above-mentioned predetermined value B. For example, when the temperature of the battery in the first power supply device 5 or the temperature of the battery in the second power supply device 6 is within the temperature region shown as the "preparation area" in the map set based on the "battery temperature-torque upper limit characteristic" as shown in FIG. 15, it is determined that there is a "state where there is little margin to the battery constraint".

In the flowchart of FIG. 14, first, in step S71, it is determined whether or not the Fr battery temperature preparation area is present. In other words, it is determined whether or not the temperature of the battery (battery temperature) in the first power supply device 5 has risen to the temperature region of the "preparation area" in the map shown in FIG. 15.

If the result of step S71 is negative because the area is not yet the Fr battery temperature preparation area, i.e., the temperature of the battery (battery temperature) in the first power supply device 5 has not risen to the temperature range of the "preparation area," proceed to step S72.

In step S72, it is determined whether or not the Rr battery temperature preparation area is reached. In other words, it is determined whether or not the temperature of the battery (battery temperature) in the second power supply device 6 has risen to the temperature region of the "preparation area" in the map shown in FIG. 15.

If the result of step S72 is negative because the Rr battery temperature preparation area is not yet reached, that is, the temperature of the battery (battery temperature) in the second power supply device 6 has not yet risen to the temperature range of the "preparation area," proceed to step S73.

In step S73, the "normal mode" is set. That is, the driving mode of the vehicle Ve is set to a normal driving mode in which the output of neither of the power supplies 5, 6 is limited. In the "normal mode", when executing the yaw rate control as shown in FIG. 11 and FIG. 12, either the front-rear distribution type in which the power is divided between the front wheels 13, 14 and the rear wheels 15, 16, or the left-right distribution type in which the power is divided between the left wheels 13, 15 and the right wheels 14, 16, is selected. In the vehicle Ve in this embodiment of the invention, the front-rear distribution type distributes the driving force across the first power supply 5 and the second power supply 6. The left-right distribution type distributes the driving force without crossing between the first power supply 5 and the second power supply 6.

In this "normal mode", the above-mentioned front/rear distribution type and left/right distribution type are appropriately selected according to the driving state of the vehicle Ve. Normally, when the vehicle accelerates or decelerates while cornering, the dynamic load of the vehicle moves in the front/rear direction. Therefore, the greater the load, the stronger the grip force, and the more driving force or braking force can be transmitted to the road surface. In addition, a control technology is known that stabilizes the vehicle behavior by distributing driving force more toward rear wheel drive when entering a corner, suppressing understeer of the vehicle, and distributing driving force more toward front wheel drive after the middle of the corner in order to suppress oversteer of the vehicle. When the "normal mode" is set in this step S73, the routine shown in the flowchart of FIG. 14 is then temporarily terminated.

On the other hand, if the above step S71 is answered in the affirmative because the Fr battery temperature preparation area is reached, that is, the battery temperature (battery temperature) in the first power supply device 5 has risen to the temperature range of the "preparation area," the process proceeds to step S74.

In step S74, the "constraint response mode" is set. In the "constraint response mode," when executing yaw rate control as shown in Figures 11 and 12 described above, the left/right distribution type is primarily selected, and the front/rear distribution type is secondarily selected. In other words, yaw rate control is primarily performed in a state in which the driving force is distributed without spanning between the first power supply unit 5 and the second power supply unit 6. After that, the routine shown in the flowchart of Figure 14 is temporarily terminated.

If the above step S72 is answered in the affirmative because the Rr battery temperature preparation area is reached, that is, the battery temperature (battery temperature) in the second power supply device 6 has risen to the temperature range of the "preparation area," the process proceeds to step S75.

In step S74, the "constraint-compliant mode" is set, as in step S74 above. Then, the routine shown in the flowchart in FIG. 14 is temporarily terminated.

In this way, with the control shown in the flowchart of FIG. 14, when the vehicle Ve turns, it is possible to switch in advance to a yaw rate control mode that can reduce the distribution torque of the power supply system that is expected to be constrained. Therefore, after the vehicle Ve starts turning, it is possible to achieve smooth and stable vehicle behavior.

As described above, in the vehicle control device according to the embodiment of the present invention, when the output or operation of any one or a part of the actuators (e.g., the first motor 1 or the second motor 2) is in a state in which the output or operation is limited, the output or operation of the other actuators whose output or operation is not limited is also limited. For example, when the output or operation of any one actuator (e.g., the first motor 1) is in a state in which the output or operation is limited (or is in a limited state) due to some constraint condition, temperature condition, or the occurrence of a failure, the output or operation of the other actuators (e.g., the second motor 2) that are normal, i.e., whose output or operation is not limited, and are controlled together with the actuator (the first motor 1) whose output or operation is limited, is limited to the same extent as the actuator (the first motor 1) whose output or operation is limited. Therefore, although the total output of the actuators as a whole is reduced, it is possible to avoid or suppress a situation in which the vehicle behavior becomes unstable due to a loss of balance in the driving force, braking force, etc. of each of the wheels 13, 14, 15, 16. Therefore, according to the vehicle control device of this embodiment of the invention, when the output or operation of only one of the actuators (first motor 1 or second motor 2) is limited, it is possible to prevent imbalance of the driving force, braking force, etc. that control the vehicle behavior, and to appropriately control the vehicle behavior.

1. First motor (MG; actuator)
2. Second motor (MG; actuator)
3. First Torque Vectoring Device (TVD; Actuator)
4. Second Torque Vectoring Device (TVD; Actuator)
4a (of the second torque vectoring device) planetary gear mechanism 4b (of the second torque vectoring device) reversing gear mechanism 4c (of the second torque vectoring device) reversing gear mechanism 4d (of the second torque vectoring device) input gear mechanism 4e (of the second torque vectoring device) differential control motor 4f (of the second torque vectoring device) limited differential mechanism 5 First power supply device (BAT; power supply device)
6 Third power supply device (BAT; power supply device)
7 First brake device (actuator)
8 Second brake device (actuator)
9. Third brake device (actuator)
10 Fourth brake device (actuator)
11 Detection unit
11a (detection part) accelerator position sensor 11b (detection part) brake stroke sensor (or brake switch)
11c (detection section) steering sensor (or steering angle sensor)
11d (detection section) wheel speed sensor 11e (detection section) acceleration sensor 11f (detection section) yaw rate sensor 11g (detection section) motor rotation speed sensor (or resolver)
11h (detection section) motor temperature sensor 11i (detection section) motor torque sensor 11j (detection section) battery temperature sensor 11k (detection section) SOC sensor 12 Controller (ECU)
13 Front wheel (fl; left side)
14 Front wheel (fr; right side)
15 Rear wheel (rl; left side)
16 Rear wheel (rr; right side)
17 Electric parking brake device 18 On-board brake device Ve Vehicle

Claims (1)

A vehicle control device that includes a plurality of actuators that can be individually controlled, and controls a vehicle behavior by operating the plurality of actuators,
At least two power supply systems including a first power supply system and a second power supply system;
a controller for controlling an output or operation of the actuator ;
The actuator has at least two motors, a first motor connected to the first power supply device to receive and transmit electric power, and a second motor connected to the second power supply device to receive and transmit electric power,
The controller:
determining a condition in which the output or operation of the actuator is limited;
When the output or operation of any one of the actuators is in a state in which the output or operation is limited, the output or operation of the other actuators that are not in a state in which the output or operation is limited is limited;
When the output of either the first motor or the second motor is in a state in which the output of the other of the first motor or the second motor is not in a state in which the output of the other motor is not limited,
determining a state in which the outputs of the first power supply device and the second power supply device are limited;
When the output of either the first power supply device or the second power supply device is in a limited state, the output of the motor connected to the other power supply device of the first power supply device or the second power supply device, the other power supply device of which the output is not in a limited state, is limited.
A vehicle control device comprising:

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