Vehicle control devices

Abstract

Vehicle posture is controlled without the use of a dedicated electric motor. [Solution] The vehicle control device includes a first electric motor connected to a wheel via a first path, a second electric motor connected to the wheel via a second path, a first clutch provided in the first path, and a control system comprising a processor and memory that are communicated with each other. The control system includes a turning control mode that can be executed during turning, in which the first clutch is released to disconnect the first electric motor from the wheel. When the turning control mode is executed, the control system accelerates or decelerates the first electric motor based on the turning conditions.

Description

Technical Field

[0001] The present disclosure relates to a vehicle control device.

Background Art

[0002] Vehicles such as automobiles have a control device that controls the vehicle posture during turning travel (see Patent Document 1 or 2). Further, the control device that controls the vehicle posture includes a rotating body that applies a rotational torque in the roll direction or yaw direction to the vehicle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the rotating body that applies a rotational torque to the vehicle is rotationally driven by an electric motor. However, rotating the rotating body using a dedicated electric motor is a factor that causes the control device to increase in size and cost. For this reason, it is required to control the vehicle posture without using a dedicated electric motor.

Means for Solving the Problems

[0005] According to this disclosure, a vehicle control device includes a first electric motor connected to a wheel via a first path, a second electric motor connected to the wheel via a second path, a first clutch provided in the first path, and a control system comprising a processor and memory that are communicated with each other. The control system includes a control mode that can be executed during straight-line driving, which is a straight-line control mode in which the first clutch is engaged and the first electric motor is connected to the wheel. The control system includes a control mode that can be executed during turning driving, which is a turning control mode in which the first clutch is released and the first electric motor is disconnected from the wheel. When executing the turning control mode, the control system accelerates or decelerates the first electric motor based on the turning driving conditions. [Effects of the Invention]

[0006] According to this disclosure, the vehicle attitude can be controlled using a first electric motor that is detached from the wheels in the turning control mode, and the vehicle attitude can be controlled without using a dedicated electric motor. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 shows a vehicle equipped with a vehicle control device, which is one embodiment of the present disclosure. [Figure 2] Figure 2 shows an example of a power unit and control system. [Figure 3] Figure 3 shows an example of the basic structure of an electronic control unit. [Figure 4] Figure 4 is a collinear diagram showing the rotation of the motor-generator during forward driving. [Figure 5] Figure 5 is a cross-sectional view showing the vehicle along the VV line in Figure 1. [Figure 6] Figure 6 is a flowchart showing an example of the procedure for executing roll suppression control. [Figure 7A] Figure 7A shows an example of the rotational state of the motor generator during a left turn. [Figure 7B]Figure 7B shows an example of the rotational state of the motor generator during a left turn. [Figure 8A] Figure 8A shows an example of the rotational state of the motor generator during a right turn. [Figure 8B] Figure 8B shows an example of the rotational state of the motor generator during a right turn. [Figure 9A] Figure 9A shows an example of the rotational state of the motor generator during a right turn. [Figure 9B] Figure 9B shows an example of the rotational state of the motor generator during a right turn. [Figure 10] Figure 10 shows a modified example of a vehicle control device. [Figure 11] Figure 11 shows a vehicle with a modified mounting position for the power unit. [Figure 12] Figure 12 is a cross-sectional view showing the vehicle along the line XII-XII in Figure 11. [Figure 13] Figure 13 is a flowchart showing an example of the procedure for performing control to improve turning ability. [Figure 14] Figure 14 shows an example of the rotational state of the motor generator during a left turn. [Figure 15] Figure 15 shows an example of the rotational state of the motor generator during a right turn. [Figure 16] Figure 16 shows an example of the rotational state of the motor generator during a right turn. [Figure 17] Figure 17 is a flowchart showing an example of the procedure for executing oversteer suppression control. [Figure 18] Figure 18 shows an example of the rotational state of the motor generator during a right turn. [Figure 19] Figure 19 shows an example of the rotational state of the motor generator during a left turn. [Figure 20] Figure 20 shows an example of the rotational state of the motor generator during a left turn.

Best Mode for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present disclosure will be described in detail based on the drawings. In the following description, the same or substantially the same components and elements are denoted by the same reference numerals, and repeated descriptions thereof are omitted.

[0009] <Power Unit> FIG. 1 is a diagram showing a vehicle 11 equipped with a vehicle control device 10 according to an embodiment of the present disclosure. As shown in FIG. 1, the vehicle control device 10 mounted on the vehicle 11 has a power unit 12 and a control system 13. The power unit 12 includes a differential 16 connected to front wheels (wheels) 14L and 14R via an axle 15, and a planetary gear mechanism 17 connected to the differential 16. Further, the power unit 12 includes a motor generator (first electric motor) MG1 connected to the planetary gear mechanism 17, and a motor generator (second electric motor) MG2 connected to the planetary gear mechanism 17.

[0010] FIG. 2 is a diagram showing an example of the power unit 12 and the control system 13. As shown in FIG. 2, the planetary gear mechanism 17 of the power unit 12 is constituted by a so-called single pinion type planetary gear train 20. That is, the planetary gear mechanism 17 includes a sun gear (first rotating element) S meshing with a pinion P, a carrier C rotatably supporting the pinion P, and a ring gear (second rotating element) R meshing with the pinion P. As will be described later, the planetary gear mechanism 17 has a structure in which the sun gear S and the ring gear R are arranged at both ends on a collinearity diagram. Note that the ring gear R is also called an internal gear.

[0011] The sun gear S of the planetary gear mechanism 17 is connected to the front wheels 14L and 14R via the gear train 21, differential 16, and axle 15. Furthermore, the sun gear S of the planetary gear mechanism 17 is connected to the rotor 31r of the motor generator MG1 via a power transmission path (first path) 24 consisting of the gear train 22, first clutch C1, and shaft 23. Additionally, the ring gear R of the planetary gear mechanism 17 is connected to the rotor 32r of the motor generator MG2 via a power transmission path (second path) 27 consisting of the gear train 25, second clutch C2, and shaft 26. In short, the planetary gear mechanism 17 is connected to the front wheels 14L and 14R, the power transmission path 24, and the power transmission path 27. Note that the clutches C1 and C2 may be hydraulic friction clutches or meshing clutches equipped with hydraulic chambers, or electromagnetic friction clutches or meshing clutches equipped with electromagnets. Furthermore, the carrier C of the planetary gear mechanism 17 is fixed to the housing 28 of the power unit 12.

[0012] Motor generator MG1 has a stator 31s equipped with stator coils and a rotor 31r housed inside the stator 31s. Similarly, motor generator MG2 has a stator 32s equipped with stator coils and a rotor 32r housed inside the stator 32s. The axes 23 and 26 of the rotors 31r and 32r of motor generators MG1 and MG2 are arranged parallel to each other. In other words, motor generators MG1 and MG2 are arranged parallel to each other. Furthermore, the end faces 31x and 32x of the rotors 31r and 32r of motor generators MG1 and MG2 are positioned facing the front-rear direction of the vehicle 11. In addition, inverter 35 is connected to the stator 31s of motor generator MG1, and inverter 36 is connected to the stator 32s of motor generator MG2. A battery pack 37 consisting of a lithium-ion battery or the like is connected to the power conversion devices inverters 35 and 36.

[0013] <Control System> As shown in Figure 2, the vehicle control device 10 has a control system 13 consisting of a plurality of electronic control units. The control system 13 includes a first motor control unit 41 that outputs a control signal to an inverter 35, and a second motor control unit 42 that outputs a control signal to an inverter 36. The control system 13 also includes a first clutch control unit 43 that outputs a control signal to a clutch C1, and a second clutch control unit 44 that outputs a control signal to a clutch C2. Furthermore, the control system 13 includes a vehicle control unit 45 that outputs control signals to the aforementioned motor control units 41, 42 and clutch control units 43, 44.

[0014] These control units 41 to 45 are connected to each other via an in-vehicle network 46 so that they can communicate with one another. The vehicle control unit 45 sets the operating targets for the motor generators MG1 and MG2 and the clutches C1 and C2 based on input information from the various control units 41 to 44 and various sensors described later. The vehicle control unit 45 also generates control signals corresponding to the operating targets for the motor generators MG1 and MG2 and the clutches C1 and C2, and outputs these control signals to the motor control units 41 and 42 and the clutch control units 43 and 44.

[0015] The control system 13 has a sensor group 50 consisting of multiple sensors connected to the vehicle control unit 45. The sensor group 50 includes a steering angle sensor 51 for detecting the steering angle of the steering wheel 47, an accelerator sensor 52 for detecting the amount of operation of the accelerator pedal, and a brake sensor 53 for detecting the amount of operation of the brake pedal. The sensor group 50 also includes an acceleration sensor 54 for detecting acceleration in the forward, backward, left, and right directions acting on the vehicle 11, and a yaw rate sensor 55 for detecting the yaw angular velocity, which is the angular velocity of the vehicle 11 around its vertical axis.

[0016] The sensor group 50 includes a rotor rotation sensor 56 for detecting the rotational speed of the rotor 31r of the motor generator MG1, and a rotor rotation sensor 57 for detecting the rotational speed of the rotor 32r of the motor generator MG2. The sensor group 50 also includes a wheel speed sensor 58 for detecting the rotational speed of the front wheel 14L, a wheel speed sensor 59 for detecting the rotational speed of the front wheel 14R, a wheel speed sensor 60 for detecting the rotational speed of the rear wheel 48L, and a wheel speed sensor 61 for detecting the rotational speed of the rear wheel 48R. In addition, a start switch 62, which is operated when starting and stopping the control system 13, is connected to the vehicle control unit 45.

[0017] Figure 3 shows an example of the basic structure of electronic control units 41 to 45. As shown in Figure 3, electronic control units 41 to 45 have a microcontroller 72 that incorporates a processor 70 and main memory (memory) 71, etc. The main memory 71 stores the program, and the processor 70 executes the program. The processor 70 and the main memory 71 are connected to each other so as to be able to communicate with each other. Note that the microcontroller 72 may incorporate multiple processors 70, and the microcontroller 72 may also incorporate multiple main memory 71.

[0018] The electronic control units 41-45 include an input circuit 73, a drive circuit 74, a communication circuit 75, an external memory 76, and a power supply circuit 77. The input circuit 73 converts signals input from various sensors into signals that can be input to the microcontroller 72. The drive circuit 74 generates drive signals for devices such as inverters 35 and 36 based on signals output from the microcontroller 72. The communication circuit 75 converts signals output from the microcontroller 72 into communication signals destined for other electronic control units. The communication circuit 75 also converts communication signals received from other electronic control units into signals that can be input to the microcontroller 72. Furthermore, the power supply circuit 77 supplies power voltage to the microcontroller 72, input circuit 73, drive circuit 74, communication circuit 75, and external memory 76. The external memory 76, consisting of non-volatile memory, stores programs and various data.

[0019] <Direction and speed of rotation of the motor-generator> Figure 4 is a collinear diagram showing the rotation of motor generators MG1 and MG2 during forward travel, and Figure 5 is a cross-sectional view showing the vehicle 11 along the VV line in Figure 1. As shown in Figure 4, the planetary gear mechanism 17 has a structure in which the sun gear S and ring gear R are arranged at both ends in the collinear diagram. In addition, the carrier C of the planetary gear mechanism 17 is located between the sun gear S and the ring gear R in the collinear diagram. Furthermore, as shown in Figure 2, the carrier C of the planetary gear mechanism 17 is fixed to the housing 28 of the power unit 12. Therefore, as shown by the solid line L1 in Figure 4, when the vehicle 11 is traveling forward, the motor generator MG1 rotates in the forward direction D1, while the motor generator MG2 rotates in the reverse direction D2.

[0020] In other words, as shown in Figures 2, 4, and 5, the rotation direction D1 of motor generator MG1 and the rotation direction D2 of motor generator MG2 are different from each other. Also, as shown in Figure 4, the rotation speed of motor generator MG1 is "N1" and the rotation speed of motor generator MG2 is "N2", but rotation speeds N1 and N2 are the same. That is, the number of teeth of the sun gear S, ring gear R, gear train 22 and gear train 25 are set so that rotation speeds N1 and N2 are the same.

[0021] As shown in Figure 2, the control system 13 executes a straight-line control mode in which both clutches C1 and C2 are engaged when the vehicle 11 is traveling in a straight line. In this straight-line control mode, both clutches C1 and C2 are engaged, so the front wheels 14L and 14R can be driven by both motor generators MG1 and MG2. Thus, the control system 13 has a straight-line control mode that can be executed when traveling in a straight line, in which clutch C1 is engaged to connect motor generator MG1 to the front wheels 14L and 14R, and clutch C2 is engaged to connect motor generator MG2 to the front wheels 14L and 14R.

[0022] <Roll suppression control> Next, roll suppression control for suppressing the rolling of the vehicle 11 will be described. Figure 6 is a flowchart showing an example of the procedure for executing roll suppression control. Figures 7A and 7B show an example of the rotation status of the motor generator MG1 during a left turn. Figures 8A and 8B show an example of the rotation status of the motor generator MG2 during a right turn. Figures 7A and 8A show the same cross-section as in Figure 5, and Figures 7B and 8B show a part of the power unit 12 shown in Figure 2.

[0023] Each step shown in the flowchart of Figure 6 is executed by the processor 70 that constitutes the control system 13. Roll suppression control is a control that is executed by the control system 13 at predetermined intervals after the control system 13 is activated by the start switch operation. Rolling of the vehicle 11 refers to the rotational motion of the vehicle 11 with the longitudinal axis of the vehicle 11 as the axis.

[0024] As shown in Figure 6, the control system 13 proceeds to step S10 and determines whether the vehicle 11 has started turning, that is, whether it has transitioned from straight-line driving to turning, based on signals from the steering angle sensor 51 and the like. If the control system 13 determines in step S10 that turning has started, it proceeds to step S11 and calculates a target reaction torque based on data indicating the turning conditions, such as vehicle speed, steering angle, and steering speed. For example, the control system 13 calculates a larger target reaction torque as the vehicle speed increases, as the steering angle increases, and as the steering speed increases.

[0025] In step S11, the control system 13 calculates the target reaction torque and then proceeds to step S12, where it determines whether the vehicle 11 is turning left based on signals from the steering angle sensor 51 and the like. If the control system 13 determines in step S12 that the vehicle is turning left, it proceeds to step S13, where it releases the clutch C1 while keeping the clutch C2 engaged and executes a first turning control mode in which it controls the motor generator MG1 based on the turning driving conditions.

[0026] In other words, as shown in Figure 7B, when the control system 13 transitions from straight-line driving to left-turn driving, it releases the clutch C1 to disconnect the motor generator MG1 from the front wheels 14L and 14R, and accelerates the motor generator MG1 based on the target reaction torque. Thus, the control system 13 has a first turning control mode (turning control mode) as a control mode that can be executed during turning driving, in which it releases the clutch C1 to disconnect the motor generator MG1 from the front wheels 14L and 14R, and engages the clutch C2 to connect the motor generator MG2 to the front wheels 14L and 14R.

[0027] As shown in Figure 7A, during a left turn, a roll moment RM1 acts on the vehicle 11, tilting it to the right. However, when transitioning from straight-line driving to a left turn, the control system 13 executes a first turning control mode that accelerates the rotor 31r of the motor generator MG1. For example, as shown by the arrow α in Figure 4, in the first turning control mode, the rotational speed of the motor generator MG1 is increased from "N1" to "N1x". As a result, as shown in Figure 7A, a reaction torque RT1 is applied from the motor generator MG1 to the vehicle 11, and this reaction torque RT1 reduces the roll moment RM1, thereby suppressing the rolling of the vehicle 11 and stabilizing the vehicle's posture.

[0028] Thus, in the first turning control mode, the motor generator MG1 is used as a reaction wheel, thereby reducing the roll moment RM1 and stabilizing the vehicle's posture. In other words, by using the motor generator MG1, which is used for wheel drive, as a reaction wheel, the vehicle's posture can be controlled without using a dedicated electric motor. Furthermore, since the first turning control mode is executed in a turning driving situation where the required driving force of the power unit 12 decreases, even if the motor generator MG1 is disconnected from the front wheels 14L and 14R, it is possible to ensure power performance using only the motor generator MG2.

[0029] When the control system 13 executes the first turning control mode in step S13, it proceeds to step S14, where it gradually decelerates the motor generator MG1, synchronizes the rotational speeds before and after the clutch, and then engages the clutch C1. In step S14, it is desirable to gradually decelerate the motor generator MG1 so as not to excessively increase the roll moment RM1. If the roll moment RM1 cannot be sufficiently reduced in step S13, the acceleration of the motor generator MG1 may be repeated multiple times.

[0030] On the other hand, if the control system 13 determines in step S12 that it is turning to the right, it proceeds to step S15, where it releases clutch C2 while clutch C1 remains engaged, and executes a second turning control mode in which it controls the motor generator MG2 based on the turning driving conditions.

[0031] In other words, as shown in Figure 8B, when the control system 13 transitions from straight-line driving to right-hand turning driving, it releases the clutch C2 to disconnect the motor generator MG2 from the front wheels 14L and 14R, and accelerates the motor generator MG2 based on the target reaction torque. Thus, the control system 13 has a second turning control mode (second turning control mode) as a control mode that can be executed during turning driving, in which the clutch C1 is engaged to connect the motor generator MG1 to the front wheels 14L and 14R, and the clutch C2 is released to disconnect the motor generator MG2 from the front wheels 14L and 14R.

[0032] As shown in Figure 8A, during a right turn, a roll moment RM2 acts on the vehicle 11, tilting it to the left. However, when transitioning from straight-line driving to a right turn, the control system 13 executes a second turning control mode that accelerates the rotor 32r of the motor generator MG2. For example, as shown by the arrow β in Figure 4, in the second turning control mode, the rotational speed of the motor generator MG2 is increased from "N2" to "N2x". As a result, as shown in Figure 8A, a reaction torque RT2 is applied from the motor generator MG2 to the vehicle 11, and this reaction torque RT2 reduces the roll moment RM2, thereby suppressing the rolling of the vehicle 11 and stabilizing the vehicle's posture.

[0033] Thus, in the second turning control mode, the motor generator MG2 is used as a reaction wheel, which reduces the roll moment RM2 and stabilizes the vehicle's posture. In other words, by using the motor generator MG2, which is used for wheel drive, as a reaction wheel, the vehicle's posture can be controlled without using a dedicated electric motor. Furthermore, since the second turning control mode is executed in a turning driving situation where the required driving force of the power unit 12 decreases, it is possible to ensure power performance using only the motor generator MG1, even if the motor generator MG2 is disconnected from the front wheels 14L and 14R.

[0034] When the control system 13 executes the second turning control mode in step S15, it proceeds to step S16, where it gradually decelerates the motor generator MG2, synchronizes the rotational speeds before and after the clutch, and then engages the clutch C2. In step S16, it is desirable to gradually decelerate the motor generator MG2 so as not to excessively increase the roll moment RM2. If the roll moment RM2 cannot be sufficiently reduced in step S15, the acceleration of the motor generator MG2 may be repeated multiple times.

[0035] As explained above, motor generator MG1 is used as a reaction wheel when turning to the right, and motor generator MG2 is used as a reaction wheel when turning to the left. Here, as shown in Figure 5, the rotation direction D1 of motor generator MG1 and the rotation direction D2 of motor generator MG2 are different from each other. As a result, when using motor generators MG1 and MG2 as reaction wheels, the rotor 31r of motor generator MG1 can be accelerated, and the rotor 32r of motor generator MG2 can be accelerated.

[0036] In other words, the vehicle speed range in which the turning control mode is executed is assumed to be the low vehicle speed range, that is, the range in which the rotational speed of rotors 31r and 32r is low. For this reason, it is difficult to obtain a large reaction torque by decelerating rotors 31r and 32r, but a large reaction torque can be obtained by accelerating rotors 31r and 32r, making it easy to reduce the roll moments RM1 and RM2 by the reaction torque.

[0037] In the above explanation, reaction torque is generated by accelerating the motor generators MG1 and MG2, but this is not the only method; reaction torque can also be generated by decelerating the motor generators MG1 and MG2. Here, Figures 9A and 9B show an example of the rotational state of motor generator MG1 during a right turn. Figure 9A shows a cross-section similar to that in Figure 5, and Figure 9B shows a part of the power unit 12 shown in Figure 2.

[0038] As shown in Figures 9A and 9B, when the control system 13 transitions from straight-line driving to right-hand turning, it releases the clutch C1 to disconnect the motor generator MG1 from the front wheels 14L and 14R, and decelerates the motor generator MG1 based on the target reaction torque. As shown in Figure 9A, during right-hand turning, a roll moment RM2 acts on the vehicle 11, tilting it to the left. However, when the control system 13 transitions from straight-line driving to right-hand turning, it executes a first turning control mode that decelerates the rotor 31r of the motor generator MG1. For example, as shown by the arrow γ in Figure 4, in the first turning control mode, the rotational speed of the motor generator MG1 is reduced from "N1" to "N1y". As a result, as shown in Figure 9A, a reaction torque RT3 is applied from the motor generator MG1 to the vehicle 11, and this reaction torque RT3 reduces the roll moment RM2, thereby suppressing the rolling of the vehicle 11 and stabilizing the vehicle's posture.

[0039] <Example 1> In the example shown in Figure 2, a clutch C2 is provided in the power transmission path connecting the planetary gear mechanism 17 and the motor generator MG2, but this is not the only option, and the clutch C2 may be omitted from the power transmission path. Figure 10 shows a modified vehicle control device 80. As shown in Figure 10, the vehicle control device 80 has a power unit 81 and a control system 82.

[0040] As shown in Figure 10, the control system 82 that controls the power unit 81 comprises a first motor control unit 41, a second motor control unit 42, a first clutch control unit 43, and a vehicle control unit 45. The power unit 81 also includes a planetary gear mechanism 17, a clutch C1, and motor generators MG1 and MG2. Furthermore, the ring gear R of the planetary gear mechanism 17 is connected to the rotor 32r of the motor generator MG2 via a power transmission path (second path) 83 consisting of a gear train 25 and a shaft 26.

[0041] Thus, even when the clutch is omitted from the power transmission path 83 connecting the planetary gear mechanism 17 and the motor generator MG2, the roll moments RM1 and RM2 can be reduced and the vehicle posture stabilized by using the motor generator MG1 as a reaction wheel. In other words, as shown in Figures 7A and 7B, when turning left, the clutch C1 is released to disconnect the motor generator MG1 from the front wheels 14L and 14R, and the motor generator MG1 is accelerated based on the target reaction torque. On the other hand, as shown in Figures 9A and 9B, when turning right, the clutch C1 is released to disconnect the motor generator MG1 from the front wheels 14L and 14R, and the motor generator MG1 is decelerated based on the target reaction torque.

[0042] As mentioned above, even when turning to the left or right, the motor generator MG1 alone can be used as a reaction wheel. Therefore, as shown in Figure 10, even when using a power unit 81 in which the clutch is omitted from the power transmission path 83, the vehicle posture can be stabilized. In other words, the control system 82 has a straight-line control mode that can be executed when driving straight, in which the clutch C1 is engaged and the motor generator MG1 is connected to the front wheels 14L and 14R. The control system 13 also has a turning control mode that can be executed when driving around, in which the clutch C1 is released and the motor generator MG1 is disconnected from the front wheels 14L and 14R.

[0043] <Modification 2> <Turning performance improvement control> In the example shown in Figure 1, the motor generators MG1 and MG2 are positioned so that the end faces 31x and 32x of the rotors 31r and 32r face in the front-rear direction of the vehicle 11. However, this is not the only option, and the motor generators MG1 and MG2 may be positioned so that the end faces 31x and 32x of the rotors 31r and 32r face in the up-down direction of the vehicle 11. Figure 11 shows a vehicle 90 with a modified mounting orientation of the power unit 12, and Figure 12 is a cross-sectional view of the vehicle 90 along the line XII-XII in Figure 11. As shown in Figures 11 and 12, the motor generators MG1 and MG2 of the power unit 12 are positioned parallel to each other. Furthermore, the motor generators MG1 and MG2 are positioned so that the end faces 31x and 32x of the rotors 31r and 32r face in the up-down direction of the vehicle 90.

[0044] Next, we will explain the control for improving turning ability to promote yawing of the vehicle 90. Figure 13 is a flowchart showing an example of the procedure for executing the control for improving turning ability. Figure 14 shows an example of the rotation status of the motor generator MG1 during a left turn. Figure 15 shows an example of the rotation status of the motor generator MG2 during a right turn. Figures 14 and 15 show a part of the power unit 12 shown in Figure 11.

[0045] Each step shown in the flowchart of Figure 13 is executed by the processor 70 that constitutes the control system 13. Furthermore, the turning performance improvement control is a control that is executed by the control system 13 at predetermined intervals after the control system 13 is activated by the operation of the start switch. Note that the yawing of the vehicle 90 is the rotational motion of the vehicle 90 with the vertical axis of the vehicle 90 as the axis.

[0046] As shown in Figure 13, the control system 13 proceeds to step S20 and determines whether the vehicle 90 has started turning, that is, whether it has transitioned from straight-line driving to turning, based on signals from the steering angle sensor 51, etc. If the control system 13 determines in step S20 that turning has started, it proceeds to step S21 and calculates the target reaction torque based on data indicating the turning conditions, such as vehicle speed, steering angle, and steering speed. For example, the control system 13 calculates a larger target reaction torque as the vehicle speed increases, as the steering angle increases, and as the steering speed increases.

[0047] In step S21, the control system 13 calculates the target reaction torque and then proceeds to step S22, where it determines whether the vehicle 90 is turning left based on signals from the steering angle sensor 51 and the like. If the control system 13 determines in step S22 that the vehicle is turning left, it proceeds to step S23, where it releases the clutch C1 while keeping the clutch C2 engaged and executes a first turning control mode in which it controls the motor generator MG1 based on the turning driving conditions.

[0048] In other words, as shown in Figure 14, when the control system 13 transitions from straight-line driving to left-turn driving, it releases clutch C1 to disconnect the motor generator MG1 from the front wheels 14L and 14R, and accelerates the motor generator MG1 based on the target reaction torque. Thus, the control system 13 has a first turning control mode (turning control mode) as a control mode that can be executed during turning driving, in which it releases clutch C1 to disconnect the motor generator MG1 from the front wheels 14L and 14R, and engages clutch C2 to connect the motor generator MG2 to the front wheels 14L and 14R.

[0049] As shown in Figure 14, in order to improve the turning ability of the vehicle 90 when turning left, it is necessary to apply a yaw moment YM1 to the vehicle 90 that causes the front of the vehicle to turn to the left. Therefore, when the control system 13 transitions from straight driving to left turning driving, it executes a first turning control mode in which it accelerates the rotor 31r of the motor generator MG1. For example, as shown by the arrow α in Figure 4, in the first turning control mode, the rotational speed of the motor generator MG1 is increased from "N1" to "N1x". As a result, as shown in Figure 14, a reaction torque RTa1 is applied from the motor generator MG1 to the vehicle 90, and this reaction torque RTa1 increases the yaw moment YM1, thereby promoting yawing of the vehicle 90 and improving its turning ability.

[0050] Thus, in the first turning control mode, the motor generator MG1 is used as a reaction wheel, which increases the yaw moment YM1 and improves turning ability. In other words, by using the motor generator MG1 for wheel drive as a reaction wheel, turning ability can be improved without using a dedicated electric motor, and the vehicle attitude can be actively controlled. Furthermore, since the situation in which the first turning control mode is executed is a turning driving situation in which the required driving force of the power unit 12 decreases, it is possible to ensure power performance using only the motor generator MG2 even if the motor generator MG1 is disconnected from the front wheels 14L and 14R.

[0051] When the control system 13 executes the first turning control mode in step S23, it proceeds to step S24, where it gradually decelerates the motor generator MG1, synchronizes the rotational speeds before and after the clutch, and then engages the clutch C1. In step S24, it is desirable to gradually decelerate the motor generator MG1 so as not to excessively reduce the yaw moment YM1. Also, if it is not possible to sufficiently increase the yaw moment YM1 in step S23, the acceleration of the motor generator MG1 may be repeated multiple times.

[0052] On the other hand, if the control system 13 determines in step S22 that it is turning to the right, it proceeds to step S25, where it releases clutch C2 while clutch C1 remains engaged, and executes a second turning control mode in which it controls the motor generator MG2 based on the turning driving conditions.

[0053] In other words, as shown in Figure 15, when the control system 13 transitions from straight-line driving to right-hand turning driving, it releases the clutch C2 to disconnect the motor generator MG2 from the front wheels 14L and 14R, and accelerates the motor generator MG2 based on the target reaction torque. Thus, the control system 13 has a second turning control mode (second turning control mode) as a control mode that can be executed during turning driving, in which the clutch C1 is engaged to connect the motor generator MG1 to the front wheels 14L and 14R, and the clutch C2 is released to disconnect the motor generator MG2 from the front wheels 14L and 14R.

[0054] As shown in Figure 15, in order to improve the turning ability of the vehicle 90 when turning right, it is necessary to apply a yaw moment YM2 to the vehicle 90 that causes the front of the vehicle to turn to the right. Therefore, when the control system 13 transitions from straight driving to right turning driving, it executes a second turning control mode in which it accelerates the rotor 32r of the motor generator MG2. For example, as shown by the arrow β in Figure 4, in the second turning control mode, the rotational speed of the motor generator MG2 is increased from "N2" to "N2x". As a result, as shown in Figure 15, a reaction torque RTa2 is applied from the motor generator MG2 to the vehicle 90, and this reaction torque RTa2 increases the yaw moment YM2, thereby promoting yawing of the vehicle 90 and improving its turning ability.

[0055] Thus, in the second turning control mode, the motor generator MG2 is used as a reaction wheel, which increases the yaw moment YM2 and improves turning ability. In other words, by using the motor generator MG2 for wheel drive as a reaction wheel, turning ability can be improved without using a dedicated electric motor, and the vehicle attitude can be actively controlled. Furthermore, since the second turning control mode is executed in a turning driving situation in which the required driving force of the power unit 12 decreases, it is possible to ensure power performance using only the motor generator MG1 even if the motor generator MG2 is disconnected from the front wheels 14L and 14R.

[0056] When the control system 13 executes the second turning control mode in step S25, it proceeds to step S26, where it gradually decelerates the motor generator MG2, synchronizes the rotational speeds before and after the clutch, and then engages the clutch C2. In step S26, it is desirable to gradually decelerate the motor generator MG2 so as not to excessively reduce the yaw moment YM2. Also, if it is not possible to sufficiently increase the yaw moment YM2 in step S25, the acceleration of the motor generator MG2 may be repeated multiple times.

[0057] As explained above, motor generator MG1 is used as a reaction wheel when turning to the right, and motor generator MG2 is used as a reaction wheel when turning to the left. Here, as shown in Figure 2, the rotation direction D1 of motor generator MG1 and the rotation direction D2 of motor generator MG2 are different from each other. As a result, when using motor generators MG1 and MG2 as reaction wheels, the rotor 31r of motor generator MG1 can be accelerated, and the rotor 32r of motor generator MG2 can be accelerated.

[0058] In other words, the vehicle speed range in which the turning control mode is executed is assumed to be the low vehicle speed range, that is, the range in which the rotational speed of rotors 31r and 32r is low. For this reason, it is difficult to obtain a large reaction torque by decelerating rotors 31r and 32r, but a large reaction torque can be obtained by accelerating rotors 31r and 32r, making it easy to increase the yaw moments YM1 and YM2 by using the reaction torque.

[0059] In the explanation above, reaction torque is generated by accelerating the motor generators MG1 and MG2, but this is not the only way; reaction torque can also be generated by decelerating the motor generators MG1 and MG2. Here, Figure 16 shows an example of the rotational state of motor generator MG1 during a right turn. Figure 16 shows a part of the power unit 12 shown in Figure 2.

[0060] As shown in Figure 16, in order to improve the turning ability of the vehicle 90 when turning right, it is necessary to apply a yaw moment YM2 to the vehicle 90 that causes it to turn to the right. Therefore, when the control system 13 transitions from straight driving to right turning driving, it releases the clutch C1 to disconnect the motor generator MG1 from the front wheels 14L and 14R and executes a first turning control mode in which the motor generator MG1 is decelerated based on the target reaction torque. For example, as shown by the arrow γ in Figure 4, in the first turning control mode, the rotational speed of the motor generator MG1 is reduced from "N1" to "N1y". As a result, as shown in Figure 16, a reaction torque RTa3 is applied from the motor generator MG1 to the vehicle 90, and this reaction torque RTa3 increases the yaw moment YM2, thereby promoting yawing of the vehicle 90 and improving its turning ability.

[0061] <Variation 3> <Oversteer suppression control> The flowchart in Figure 13 describes the execution of turn-response improvement control that promotes yawing of vehicle 90, but the execution of control is not limited to turn-response improvement control. In other words, using the vehicle 90 shown in Figure 11, oversteer suppression control that suppresses yawing of vehicle 90 may also be executed. The following describes oversteer suppression control for suppressing yawing of vehicle 90. Figure 17 is a flowchart of an example of the execution procedure for oversteer suppression control. Figure 18 is a diagram showing an example of the rotation status of motor generator MG1 during a right turn. Figure 19 is a diagram showing an example of the rotation status of motor generator MG2 during a left turn. Figures 18 and 19 show a part of the power unit 12 shown in Figure 11.

[0062] Each step shown in the flowchart of Figure 17 is performed by the processor 70 that constitutes the control system 13. Oversteer suppression control is a control that is performed by the control system 13 at predetermined intervals after the control system 13 is activated by the start switch operation.

[0063] As shown in Figure 17, the control system 13 proceeds to step S30 and determines whether the vehicle 90 is turning based on signals from the steering angle sensor 51, etc. If the control system 13 determines in step S30 that the vehicle is turning, it proceeds to step S31 and determines whether the yaw rate, or yaw angular velocity, of the vehicle 90 exceeds the threshold YR1. If the control system 13 determines in step S31 that the yaw angular velocity exceeds the threshold YR1, it proceeds to step S32 and calculates the target reaction torque based on the yaw acceleration, which indicates the turning condition of the vehicle 90. For example, the control system 13 calculates a larger target reaction torque as the yaw acceleration increases.

[0064] In step S32, the control system 13 calculates the target reaction torque and then proceeds to step S33, where it determines whether the vehicle 90 is turning to the right based on signals from the steering angle sensor 51 and the like. If the control system 13 determines in step S33 that the vehicle is turning to the right, it proceeds to step S34, where it releases the clutch C1 while keeping the clutch C2 engaged and executes a first turning control mode in which it controls the motor generator MG1 based on the turning driving conditions.

[0065] In other words, as shown in Figure 18, when the yaw angular velocity increases during right-hand turning, the control system 13 releases clutch C1 to disconnect the motor generator MG1 from the front wheels 14L and 14R, and accelerates the motor generator MG1 based on the target reaction torque. Thus, the control system 13 has a first turning control mode (turning control mode) as a control mode that can be executed during turning, in which clutch C1 is released to disconnect the motor generator MG1 from the front wheels 14L and 14R, and clutch C2 is engaged to connect the motor generator MG2 to the front wheels 14L and 14R.

[0066] As shown in Figure 18, in order to suppress oversteer during a right turn, it is necessary to reduce the yaw moment YMb1 that causes the front of the vehicle to turn to the right. Therefore, when the yaw angular velocity increases during a right turn, the control system 13 executes a first turning control mode in which it accelerates the rotor 31r of the motor generator MG1. For example, as shown by the arrow α in Figure 4, in the first turning control mode, the rotational speed of the motor generator MG1 is increased from "N1" to "N1x". As a result, as shown in Figure 18, a reaction torque RTb1 is applied from the motor generator MG1 to the vehicle 90, and this reaction torque RTb1 reduces the yaw moment YMb1, thereby suppressing oversteer of the vehicle 90 and stabilizing the vehicle's attitude.

[0067] Thus, in the first turning control mode, the motor generator MG1 is used as a reaction wheel, which reduces the yaw moment YMb1 and stabilizes the vehicle's attitude. In other words, by using the motor generator MG1, which is used for wheel drive, as a reaction wheel, the vehicle's attitude can be controlled without using a dedicated electric motor. Furthermore, since the first turning control mode is executed in a turning driving situation where the required driving force of the power unit 12 decreases, even if the motor generator MG1 is disconnected from the front wheels 14L and 14R, it is possible to ensure power performance using only the motor generator MG2.

[0068] When the control system 13 executes the first turning control mode in step S34, it proceeds to step S35, where it gradually decelerates the motor generator MG1, synchronizes the rotational speeds before and after the clutch, and then engages the clutch C1. In step S35, it is desirable to gradually decelerate the motor generator MG1 so as not to excessively increase the yaw moment YMb1. If the yaw moment YMb1 cannot be sufficiently reduced in step S34, the acceleration of the motor generator MG1 may be repeated multiple times.

[0069] On the other hand, if the control system 13 determines in step S33 that it is turning left, it proceeds to step S36, where it releases clutch C2 while clutch C1 remains engaged, and executes a second turning control mode in which it controls the motor generator MG2 based on the turning driving conditions.

[0070] In other words, as shown in Figure 19, when the yaw angular velocity increases during left-hand turning, the control system 13 releases the clutch C2 to disconnect the motor generator MG2 from the front wheels 14L and 14R, and accelerates the motor generator MG2 based on the target reaction torque. Thus, the control system 13 has a second turning control mode (second turning control mode) as a control mode that can be executed during turning, in which the clutch C1 is engaged to connect the motor generator MG1 to the front wheels 14L and 14R, and the clutch C2 is released to disconnect the motor generator MG2 from the front wheels 14L and 14R.

[0071] As shown in Figure 19, in order to suppress oversteer during a left turn, it is necessary to reduce the yaw moment YMb2 that causes the front of the vehicle to turn to the left. Therefore, when the yaw angular velocity increases during left turn driving, the control system 13 executes a second turning control mode in which it accelerates the rotor 32r of the motor generator MG2. For example, as shown by the arrow β in Figure 4, in the second turning control mode, the rotational speed of the motor generator MG2 is increased from "N2" to "N2x". As a result, as shown in Figure 19, a reaction torque RTb2 is applied from the motor generator MG2 to the vehicle 90, and this reaction torque RTb2 reduces the yaw moment YMb2, thereby suppressing oversteer of the vehicle 90 and stabilizing the vehicle's attitude.

[0072] Thus, in the second turning control mode, the motor generator MG2 is used as a reaction wheel, which reduces the yaw moment YMb2 and stabilizes the vehicle's attitude. In other words, by using the motor generator MG2, which is used for wheel drive, as a reaction wheel, the vehicle's attitude can be controlled without using a dedicated electric motor. Furthermore, since the second turning control mode is executed in a turning driving situation where the required driving force of the power unit 12 decreases, it is possible to ensure power performance using only the motor generator MG1, even if the motor generator MG2 is disconnected from the front wheels 14L and 14R.

[0073] When the control system 13 executes the second turning control mode in step S36, it proceeds to step S37, where it gradually decelerates the motor generator MG2, synchronizes the rotational speeds before and after the clutch, and then engages the clutch C2. In step S37, it is desirable to gradually decelerate the motor generator MG2 so as not to excessively increase the yaw moment YMb2. If the yaw moment YMb2 cannot be sufficiently reduced in step S36, the acceleration of the motor generator MG2 may be repeated multiple times.

[0074] As explained above, motor generator MG1 is used as a reaction wheel when turning to the right, and motor generator MG2 is used as a reaction wheel when turning to the left. Here, as shown in Figure 2, the rotation direction D1 of motor generator MG1 and the rotation direction D2 of motor generator MG2 are different from each other. As a result, when using motor generators MG1 and MG2 as reaction wheels, the rotor 31r of motor generator MG1 can be accelerated, and the rotor 32r of motor generator MG2 can be accelerated.

[0075] In other words, the vehicle speed range in which the turning control mode is executed is assumed to be the low vehicle speed range, that is, the range in which the rotational speed of rotors 31r and 32r is low. For this reason, it is difficult to obtain a large reaction torque by decelerating rotors 31r and 32r, but a large reaction torque can be obtained by accelerating rotors 31r and 32r, making it easy to reduce the yaw moments YMb1 and YMb2 by the reaction torque.

[0076] In the explanation above, reaction torque is generated by accelerating the motor generators MG1 and MG2, but this is not the only way; reaction torque can also be generated by decelerating the motor generators MG1 and MG2. Here, Figure 20 shows an example of the rotational state of motor generator MG1 during left turn. Figure 20 shows a part of the power unit 12 shown in Figure 11.

[0077] As shown in Figure 20, in order to suppress oversteer during a left turn, it is necessary to reduce the yaw moment YMb2 that causes the front of the vehicle to turn to the left. Therefore, when the yaw angular velocity increases during left turn driving, the control system 13 releases the clutch C1 to disconnect the motor generator MG1 from the front wheels 14L and 14R, and executes a first turning control mode in which the motor generator MG1 is decelerated based on the target reaction torque. For example, as shown by the arrow γ in Figure 4, in the first turning control mode, the rotational speed of the motor generator MG1 is reduced from "N1" to "N1y". As a result, as shown in Figure 20, a reaction torque RTb3 is applied from the motor generator MG1 to the vehicle 90, and this reaction torque RTb3 reduces the yaw moment YMb2, thereby suppressing oversteer of the vehicle 90 and stabilizing the vehicle's attitude.

[0078] <Other variations> This disclosure is not limited to the embodiments described above, and it goes without saying that various modifications are possible without departing from the spirit thereof. In the illustrated example, a power unit 12 that drives the front wheels 14L and 14R is used, but it is not limited thereto. For example, it may be a power unit that drives the rear wheels 48L and 48R, or a power unit that drives both the front wheels 14L and 14R and the rear wheels 48L and 48R. In the illustrated example, the control system 13 is configured by a plurality of electronic control units 41 to 45, but it is not limited thereto, and the control system 13 may be configured by a single electronic control unit.

[0079] In the illustrated example, the motor generator MG1 is connected to the sun gear S and the motor generator MG2 is connected to the ring gear R, but this is not limited to this configuration. The motor generator MG1 may be connected to the ring gear R and the motor generator MG2 may be connected to the sun gear S. In the illustrated example, the planetary gear mechanism 17 is configured using a single-pinion type planetary gear train 20, but this is not limited to this configuration. For example, the planetary gear mechanism 17 may be configured using a double-pinion type planetary gear train. In the illustrated example, the planetary gear mechanism 17 is incorporated into the power unit 12, but this is not limited to this configuration. For example, the motor generators MG1 and MG2 may be connected to the front wheels 14L and 14R or the rear wheels 48L and 48R without using the planetary gear mechanism 17.

[0080] In the above explanation, the rotational speeds N1 of motor-generator MG1 and N2 of motor-generator MG2 are the same when both clutches C1 and C2 are engaged, but this is not the only case. In other words, when both clutches C1 and C2 are engaged, the rotational speeds N1 of motor-generator MG1 and N2 of motor-generator MG2 may be different. Furthermore, by making the rotational speeds N1 and N2 the same, it becomes easier to set the target reaction torque for controlling motor-generators MG1 and MG2. Also, in the illustrated example, the carrier C of the planetary gear mechanism 17 is fixed to the housing 28, but this is not the only case, and the rotational speed of the carrier C may be controlled using an electric motor.

[0081] In the above explanation, the power unit 12 shown in Figure 2 is used to perform the turning performance improvement control in Figure 13 and the oversteer suppression control in Figure 17, but this is not the only option. For example, the power unit 81 shown in Figure 10 may be used to perform the turning performance improvement control in Figure 13 and the oversteer suppression control in Figure 17. In other words, turning performance improvement control may be performed by accelerating or decelerating one of the motor generators MG1 to increase the left and right yaw moments YM1 and YM2. Alternatively, oversteer suppression control may be performed by accelerating or decelerating one of the motor generators MG1 to decrease the left and right yaw moments YMb1 and YMb2. [Explanation of symbols]

[0082] 10...Vehicle control device, 13...Control system, 14L, 14R...Front wheel, 17...Planetary gear mechanism, 24...Power transmission path (first path), 27...Power transmission path (second path), 70...Processor, 71...Main memory, 80...Vehicle control device, 82...Control system, 83...Power transmission path (second path), MG1...Motor generator (first electric motor), MG2...Motor generator (second electric motor), C1...Clutch (first clutch), C2...Clutch (second clutch), S...Sun gear (first rotating element), R...Ring gear (second rotating element), D1, D2...Rotation direction

Claims

1. A first electric motor connected to the wheel via a first path, A second electric motor connected to the wheel via a second path, A first clutch provided in the first path, A control system comprising a processor and memory connected to each other in a manner that enables communication, It has, The control system is A control mode that can be executed when driving in a straight line, comprising a straight-line control mode in which the first clutch is engaged and the first electric motor is connected to the wheel, A control mode that can be executed during turning, comprising a turning control mode in which the first clutch is released and the first electric motor is disconnected from the wheel, It is equipped with, The control system is When the turning control mode is executed, the first electric motor is accelerated or decelerated based on the turning driving conditions. Vehicle control device.

2. In the vehicle control device according to claim 1, The second path has a second clutch, The control system is When executing the straight-line control mode, the first clutch is engaged to connect the first electric motor to the wheel, and the second clutch is engaged to connect the second electric motor to the wheel. When executing the turning control mode, the first clutch is released to disconnect the first electric motor from the wheel, and the second clutch is engaged to connect the second electric motor to the wheel. Vehicle control device.

3. In the vehicle control device according to claim 2, The control system is This control mode is executable during turning and includes a second turning control mode in which the first clutch is engaged to connect the first electric motor to the wheel, and the second clutch is released to disconnect the second electric motor from the wheel. The control system is When executing the second turning control mode, the second electric motor is accelerated or decelerated based on the turning driving conditions. Vehicle control device.

4. In the vehicle control device according to claim 1, The vehicle has the aforementioned wheels, a planetary gear mechanism connected to the first path and the second path, The planetary gear mechanism comprises a first rotating element connected to the first path and a second rotating element connected to the second path. The planetary gear mechanism has a structure in which the first rotating element and the second rotating element are arranged at both ends in the collinear diagram. Vehicle control device.

5. In the vehicle control device according to claim 1, The first electric motor and the second electric motor are arranged parallel to each other. When the straight-line control mode is executed, the rotation direction of the first electric motor and the rotation direction of the second electric motor are different from each other. Vehicle control device.

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