JP7449128B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device mounted on a vehicle.

As a method for determining the vehicle speed, which is the moving speed of the vehicle, a method has been proposed in which the slowest rotational speed of each wheel is determined as the vehicle speed (see Patent Document 1 or 2). Further, as a method for determining the vehicle speed, there are a method of calculating the vehicle speed from vehicle acceleration, etc., and a method of calculating the vehicle speed from a position signal of a GPS (Global Positioning System).

Japanese Patent Application Publication No. 2005-343398 JP2016-103867A

However, it has been difficult to appropriately detect the vehicle speed in situations where all wheels slip or when the vehicle is traveling on an uphill or downhill road.

An object of the present invention is to appropriately detect the moving speed of a vehicle.

A vehicle control device of the present invention is a vehicle control device mounted on a vehicle, and includes a power source including a rotating body connected to a drive wheel via a power transmission path, and a state in which the drive wheel is in slip state. an angular acceleration detection unit that detects the angular acceleration generated on the rotating body under the conditions of a target angular acceleration setting unit that sets a target angular acceleration of the rotary body at which slip of the drive wheel is eliminated based on the angular acceleration and the torque; and a rotation comprising the drive wheel, the power transmission path, and the rotary body. a target torque setting unit that multiplies the inertia of the system by the target angular acceleration to set a target torque of the rotating body; and a vehicle speed detection section that detects the rotational speed of the drive wheels.

The vehicle control device of the present invention is a vehicle control device mounted on a vehicle, and includes a first motor including a first rotor connected to one of the front and rear first drive wheels via a first power transmission path. and a second motor having a second rotor connected to the other front and rear second drive wheels via a second power transmission path, and a slip control execution condition based on the slip state of the first drive wheel. a slip determination unit that determines whether the slip control execution condition is satisfied; a slip control unit that controls the first motor and maintains the first drive wheel at a predetermined slip rate when the slip control execution condition is satisfied; an angular acceleration detection unit that detects angular acceleration generated at the second rotor when the second drive wheel is in a slip state; a torque detection unit that detects a torque acting on the second rotor; and a target angular acceleration setting unit that sets a target angular acceleration of the second rotor to eliminate slip of the second drive wheel based on the angular acceleration and the torque. , a target torque setting unit that multiplies the inertia of a rotation system including the second drive wheel, the second power transmission path, and the second rotor by the target angular acceleration to set a target torque of the second rotor; a vehicle speed detection section that detects the rotational speed of the second drive wheel as the moving speed of the vehicle under a state in which the second motor is controlled based on the target torque, and the slip control section A slip rate of the first drive wheel used for the slip control is calculated based on the rotation speed of the first drive wheel and the rotation speed of the second drive wheel, which is the moving speed of the vehicle.

According to the present invention, it is possible to eliminate slippage of the drive wheels, and the rotational speed of the drive wheels can be used as the moving speed of the vehicle. Thereby, the moving speed of the vehicle can be appropriately determined.

1 is a schematic diagram showing a configuration example of a vehicle equipped with a vehicle control device according to an embodiment of the present invention. FIG. 3 is a diagram showing an example of a driving force map showing required driving force. 5 is a timing chart showing an example of the execution status of front wheel slip control and rear wheel slip control during acceleration driving. 3 is a flowchart illustrating an example of an execution procedure of slip elimination control. It is a diagram showing the relationship between angular acceleration of a motor generator and power running torque. It is a diagram showing the relationship between angular acceleration of a motor generator and power running torque. 3 is a flowchart illustrating an example of an execution procedure of vehicle speed identification control. 5 is a timing chart showing an example of execution status of front wheel slip control and rear wheel slip control. 3 is a flowchart illustrating an example of an execution procedure of front wheel slip control. 3 is a flowchart illustrating an example of an execution procedure of rear wheel slip control. 3 is a flowchart illustrating an example of an execution procedure of rear wheel slip control. 5 is a timing chart showing an example of the execution status of front wheel slip control and rear wheel slip control during deceleration driving. 3 is a flowchart illustrating an example of an execution procedure of slip elimination control. FIG. 3 is a diagram showing the relationship between angular acceleration of a motor generator and regenerative torque. FIG. 3 is a diagram showing the relationship between angular acceleration of a motor generator and regenerative torque. 5 is a timing chart showing an example of execution status of front wheel slip control and rear wheel slip control.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

[Vehicle configuration]
FIG. 1 is a schematic diagram showing an example of the configuration of a vehicle 11 including a vehicle control device 10 according to an embodiment of the present invention. As shown in FIG. 1, the vehicle 11 is provided with a motor generator (first motor) MG1 that drives a front wheel (first drive wheel) 20. As shown in FIG. A front wheel 20 is connected to a rotor (first rotor) 21 of this motor generator MG1 via a first power transmission path 22. Further, a first power transmission path 22 that transmits motor power is configured by a motor output shaft 23, a front differential mechanism 24, and a front wheel drive shaft 25. Furthermore, the rotor 21, the first power transmission path 22, and the front wheels 20 constitute a front wheel rotation system 26. Note that the front wheel rotation system 26 is a rotation system that includes the front wheel 20 and each rotating element that rotates together with the front wheel 20.

The vehicle 11 is also provided with a motor generator (power source, motor, second motor) MG2 that drives the rear wheels (drive wheels, second drive wheels) 30. A rear wheel 30 is connected to a rotor 31 (rotating body, second rotor) 31 of this motor generator MG2 via a second power transmission path 32. Further, the second power transmission path 32 that transmits the motor power is constituted by a motor output shaft 33, a rear differential mechanism 34, and a rear wheel drive shaft 35. Further, the rotor 31, the second power transmission path 32, and the rear wheel 30 constitute a rear wheel rotation system (rotation system) 36. Note that the rear wheel rotation system 36 is a rotation system that includes the rear wheel 30 and each rotating element that rotates together with the rear wheel 30.

Furthermore, a battery 43 such as a lithium ion battery is connected to stators 40 and 41 of motor generators MG1 and MG2 via an inverter unit 42 that is a power conversion device. An inverter unit 42 that controls the energization state of the stators 40 and 41 is provided with an inverter 44 that connects the stator 40 and the battery 43, and an inverter 45 that connects the stator 41 and the battery 43.

[Control system]
The vehicle control device 10 is provided with a main controller 50 and a motor controller 51 including a microcomputer or the like to control the torque and rotational speed of motor generators MG1 and MG2. The main controller 50 is provided with a driving force setting section 52, a first motor control section 53, and a second motor control section 54. The driving force setting unit 52 of the main controller 50 sets the required driving force Fv for the vehicle 11 based on the driver's accelerator operation, etc., and converts this required driving force Fv into the required driving force of the front wheels 20 (hereinafter, front wheel required driving force Fft). ) and the required driving force for the rear wheels 30 (hereinafter referred to as rear wheel required driving force Frr). Note that the front-to-rear distribution ratio of the required driving force Fv may be a fixed distribution ratio set in advance, or may be a distribution ratio that changes depending on the driving situation.

First motor control section 53 of main controller 50 sets target torque Tm1 of motor generator MG1 based on front wheel required driving force Fft, and outputs this target torque Tm1 to motor controller 51. The motor controller 51 that has received the target torque Tm1 sets a target current value, etc. corresponding to the target torque Tm1, and controls the inverter 44 based on the target current value, etc. Similarly, second motor control unit 54 of main controller 50 sets target torque Tm2 of motor generator MG2 based on rear wheel required driving force Frr, and outputs this target torque Tm2 to motor controller 51. The motor controller 51 that has received the target torque Tm2 sets a target current value, etc. corresponding to the target torque Tm2, and controls the inverter 45 based on the target current value, etc.

The main controller 50 is also provided with a front wheel slip determination section (slip determination section) 55, a front wheel slip control section (slip control section) 56, a rear wheel slip determination section 57, and a rear wheel slip control section 58. As will be described later, the front wheel slip determination unit 55 determines whether an execution condition Fa for slip control of the front wheels 20 (hereinafter referred to as front wheel slip control) is satisfied based on the slip rate of the front wheels 20. Then, when execution condition Fa for front wheel slip control is satisfied, front wheel slip control section 56 executes torque control of motor generator MG1 as front wheel slip control, and rotates front wheel 20 while maintaining a predetermined slip ratio.

Similarly, the rear wheel slip determination unit 57 determines whether execution condition Ra for slip control of the rear wheels 30 (hereinafter referred to as rear wheel slip control) is satisfied based on the slip rate of the rear wheels 30. do. When execution condition Ra of rear wheel slip control is satisfied, rear wheel slip control section 58 executes torque control of motor generator MG2 as rear wheel slip control to maintain rear wheel 30 at a predetermined slip rate. Rotate while Note that the control signal from the front wheel slip control section 56 is output to the motor controller 51 via the first motor control section 53, and the control signal from the rear wheel slip control section 58 is output to the motor controller 51 via the second motor control section 54. It is output to the motor controller 51.

As a sensor connected to the main controller 50, an accelerator sensor 61 that detects the amount of depression of an accelerator pedal 60 (hereinafter referred to as accelerator opening degree Acc) is provided, and a brake sensor that detects the amount of depression of a brake pedal 62 is provided. A sensor 63 is provided. Further, as a sensor connected to the main controller 50, a front wheel rotation sensor 64 is provided that detects the rotational speed of the front wheel 20 (hereinafter referred to as front wheel speed Vft), and the rotational speed of the rear wheel 30 (hereinafter referred to as front wheel speed Vft). A rear wheel rotation sensor 65 is provided to detect the rear wheel speed Vrr. Further, as sensors connected to the main controller 50, a rotor rotation sensor 66 that detects the rotation speed of the rotor 21 of the motor generator MG1 is provided, and a rotor rotation sensor 67 that detects the rotation speed of the rotor 31 of the motor generator MG2. etc. are provided. Note that the main controller 50 and the motor controller 51 are communicably connected to each other via an in-vehicle network 68 such as CAN.

FIG. 2 is a diagram showing an example of a driving force map showing the required driving force Fv. As shown in FIG. 2, characteristic lines L1 to L5 indicating the required driving force Fv for each accelerator opening degree Acc are set in the driving force map. In other words, when the accelerator opening Acc is 0%, the required driving force Fv is set along the characteristic line L1, and when the accelerator opening Acc is 25%, the required driving force Fv is set along the characteristic line L2. The force Fv is set. Similarly, when the accelerator opening Acc is 50%, the required driving force Fv is set along the characteristic line L3, and when the accelerator opening Acc is 75%, the required driving force Fv is set along the characteristic line L4. When the driving force Fv is set and the accelerator opening degree Acc is 100%, the required driving force Fv is set along the characteristic line L5. For example, when the accelerator opening degree Acc is "50%" and the vehicle speed is "Vx", "Fx" is set as the required driving force Fv requested by the driver. Note that in the driving force map shown in FIG. 2, five characteristic lines L1 to L5 are set as an example, but the present invention is not limited to this, and the driving force map shown in FIG. You can also use a map.

[Front wheel slip control and rear wheel slip control (timing chart)]
An overview of front wheel slip control and rear wheel slip control will be explained. FIG. 3 is a timing chart showing an example of the execution status of front wheel slip control and rear wheel slip control during acceleration driving. Note that both the front wheel slip control and the rear wheel slip control are described together in the timing chart of FIG. 3. Furthermore, in FIG. 3, from the viewpoint of clarifying the transition of torque, driving force, etc., even when the lines overlap each other, these lines are shown shifted slightly.

In the following description, the slip ratio SLft of the front wheels 20 is a value indicating the slip state of the front wheels 20, and is a value calculated using the following equation (1). Further, the slip rate SLrr of the rear wheels 30 is a value indicating the slip state of the rear wheels 30, and is a value calculated using the following equation (2). Further, in equations (1) and (2), "Vv" is the vehicle speed, that is, the moving speed of the vehicle 11. That is, when the front wheels 20 and the rear wheels 30 do not spin and the front wheel speed Vft and the rear wheel speed Vrr match the vehicle speed Vv, the slip ratios SLft and SLrr are calculated as 0%. On the other hand, if the front wheels 20 and rear wheels 30 spin during acceleration and the front wheel speed Vft and rear wheel speed Vrr exceed the vehicle speed Vv, the slip ratios SLft and SLrr are on the positive side (+ side) from 0%. It is calculated as follows.
SLft={(Vft-Vv)/Vv}×100...(1)
SLrr={(Vrr-Vv)/Vv}×100...(2)

Hereinafter, front wheel slip control and rear wheel slip control during acceleration driving will be explained. Front wheel slip control and rear wheel slip control adjust the motor torque of motor generators MG1 and MG2 to control the front wheel 20 and rear wheel 30 when the front wheel 20 and rear wheel 30 are spinning on a low μ road such as a frozen road surface. This is control to maintain a predetermined slip rate Sx1 (for example, 10%). By executing this slip control, it is possible to avoid excessive spinning of the front wheels 20 and rear wheels 30, thereby improving running stability on frozen road surfaces and the like. As a condition for executing this slip control, for example, slip rates SLft and SLrr may exceed a predetermined threshold value SL1. That is, whether or not the slip control execution conditions are satisfied is determined based on the slip ratios SLft and SLrr of the front wheels 20 and the rear wheels 30. Further, as a condition for stopping the slip control, for example, slip ratios SLft and SLrr are less than a predetermined threshold value SL2.

As shown at time t1 in FIG. 3, when the accelerator opening degree Acc increases due to depression of the accelerator pedal 60, the required front wheel driving force Fft and the required rear wheel driving force Frr increase, and the target torque Tm1 of the motor generators MG1 and MG2 increases. , Tm2 increases. Then, the powering torques Tm1' and Tm2' of motor generators MG1 and MG2 increase so as to follow the target torques Tm1 and Tm2, and the actual driving forces Fft' and Frr' of the front wheels 20 and the rear wheels 30 increase. Note that the power running torques Tm1' and Tm2' are motor torques [Nm] output from the motor generators MG1 and MG2 to the power running side, and the actual driving forces Fft' and Frr' are the motor torques [Nm] output from the front wheels 20 and the rear wheels 30. The driving force is [N].

Subsequently, as shown at time t2, when the actual driving forces Fft', Frr' of the front wheels 20 and rear wheels 30 increase and exceed the road reaction force, the front wheels 20 and rear wheels 30 spin, and the slip rate SLft increases. , SLrr starts to increase. Then, as shown at time t3, when the slip ratios SLft and SLrr exceed the threshold value SL1, the front wheel slip control and the rear wheel slip control reduce the target torques Tm1 and Tm2 in order to suppress the front wheels 20 and the rear wheels 30 from spinning. is executed.

In front wheel slip control and rear wheel slip control, motor generator MG1, Target torques Tm1 and Tm2 of MG2 are controlled. That is, when the slip ratios SLft and SLrr exceed the target slip ratio Sx1, the target torques Tm1 and Tm2 are set lower, while when the slip ratios SLft and SLrr are lower than the target slip ratio Sx1, the target torque Tm1 , Tm2 are set higher. Thereby, even in a situation where the front wheels 20 and the rear wheels 30 are spinning, the slip ratios SLft and SLrr can be maintained at the target slip ratio Sx1, and the running stability of the vehicle 11 can be improved.

That is, even in a situation where the front wheel required driving force Fft and the rear wheel required driving force Frr are set large due to depression of the accelerator pedal 60, and the target torques Tm1 and Tm2 can be set large as shown by the broken line Tx, the arrow α As shown, the target torques Tm1 and Tm2 are set lower. As a result, as shown by the arrow β, the actual driving force Fft', Frr' of the front wheels 20 and rear wheels 30 can be lowered, so it is possible to avoid excessive spinning of the front wheels 20 and rear wheels 30, and to reduce the The running stability of the vehicle 11 on the μ road can be improved.

[Slip elimination control]
Next, slip elimination control for eliminating slip of the rear wheels 30 will be explained. As described above, in order to appropriately execute the front wheel slip control and the rear wheel slip control, it is necessary to detect the vehicle speed Vv with high accuracy, which affects the calculation of the slip ratios SLft and SLrr. As this vehicle speed Vv, as described later, it is possible to use the slower rotational speed of the front wheel speed Vft and the rear wheel speed Vrr, but for example, when slip occurs in both the front wheels 20 and the rear wheels 30, Since both the front wheel speed Vft and the rear wheel speed Vrr deviate from the vehicle speed Vv, it is difficult to accurately detect the vehicle speed Vv. Therefore, when slip occurs in both the front wheels 20 and the rear wheels 30, the vehicle control device 10 executes slip elimination control to eliminate the slip in the rear wheels 30 from the viewpoint of accurately detecting the vehicle speed Vv. do. In order to execute this slip elimination control, the main controller 50 is provided with an angular acceleration detection section 70, a torque detection section 71, a target angular acceleration setting section 72, a target torque setting section 73, and a vehicle speed detection section 74.

FIG. 4 is a flowchart showing an example of an execution procedure of slip cancellation control. As shown in FIG. 4, in step S10, it is determined whether or not both the front wheels 20 and the rear wheels 30 are slipping. In step S10, if both the front wheels 20 and the rear wheels 30 are slipping, that is, if both the front wheel speed Vft and the rear wheel speed Vrr deviate from the vehicle speed Vv, the process advances to step S11, and the rear wheels 30 Slip elimination control is started to eliminate the slip.

In step S11, the angular acceleration ω' of the rotor 31 of the motor generator MG2 connected to the rear wheel 30 in slip is detected, and in the subsequent step S12, the rotor 31 of the motor generator MG2 connected to the rear wheel 30 in slip is detected. The powering torque (torque) Tm2' of is detected. That is, in step S11, angular acceleration detection section 70 of main controller 50 calculates angular acceleration ω' generated in rotor 31 based on the rotational speed of motor generator MG2. In the subsequent step S12, the torque detection unit 71 of the main controller 50 calculates the power running torque Tm2' acting on the rotor 31 based on the current supplied to the stator 41 and the like.

Here, FIG. 5 is a diagram showing the relationship between angular acceleration ω' of motor generator MG2 and power running torque Tm2'. As shown by arrow A1 in FIG. 5, when the vehicle 11 runs on a high μ road such as a dry road surface, that is, when the vehicle 11 runs without idling the rear wheels 30, the power running torque is increased along the characteristic line L1a. As Tm2' increases, angular acceleration ω' gradually increases. Further, as shown by arrows B1, C1, and D1, when the vehicle 11 runs on a low μ road such as a frozen road surface or a packed snow road surface, that is, when the rear wheels 30 spin due to the magnitude of the power running torque Tm2'. In this case, when the power running torque Tm2' exceeds a predetermined value, the angular acceleration ω' increases rapidly along the characteristic lines L1b, L1c, and L1d.

That is, when the frictional resistance is small even on a low μ road, when the power running torque Tm2' exceeds the predetermined value T1, the rear wheels 30 begin to spin and the angular acceleration ω' increases rapidly. Further, when the frictional resistance is moderate even on a low μ road, when the power running torque Tm2' exceeds the predetermined value T2, the rear wheels 30 start spinning and the angular acceleration ω' increases rapidly. Further, when the frictional resistance is large even on a low μ road, when the power running torque Tm2' exceeds the predetermined value T3, the rear wheels 30 start spinning and the angular acceleration ω' increases rapidly. Note that the slopes of the characteristic lines L1b, L1c, and L1d are hardly affected by the frictional resistance of the road surface because the rear wheels 30 are idling, and are substantially constant. Further, in the illustrated example, three characteristic lines L1b, L1c, and L1d are shown, but the present invention is not limited to this, and a large number of characteristic lines can be shown depending on the frictional resistance of the road surface.

As shown in the flowchart of FIG. 4, in step S13, a characteristic line indicating the slip state of the rear wheel 30 is estimated based on the angular acceleration ω' and the power running torque Tm2', and in the subsequent step S14, the motor A target angular acceleration Tω' of the generator MG2 is set. The procedure for setting the target angular acceleration Tω' by the target angular acceleration setting section 72 will be described below. Here, FIG. 6 is a diagram similar to FIG. 5, and is a diagram showing the relationship between angular acceleration ω' of motor generator MG2 and power running torque Tm2'.

As shown in FIG. 6, when the angular acceleration ω' is "A1a" and the power running torque Tm2' is "T1a", it is considered that the rear wheel 30 is spinning along the characteristic line L1b. . Therefore, in order to eliminate the slip of the rear wheels 30, it is necessary to reduce the angular acceleration ω' until it reaches the characteristic line L1a. That is, the slip of the rear wheels 30 can be eliminated by setting the target angular acceleration Tω' to "A1b" and lowering the power running torque Tm2' as shown by the arrow X1. Further, for example, if the angular acceleration ω' is "A2a" and the power running torque Tm2' is "T2a", it is considered that the rear wheel 30 is spinning along the characteristic line L1e shown by the broken line. It will be done. In this case, the slip of the rear wheels 30 can be eliminated by setting the target angular acceleration Tω' to "A2b" and lowering the power running torque Tm2' as shown by the arrow X2.

In this way, when the target angular acceleration Tω' for eliminating the slip of the rear wheels 30 is set, the target torque setting unit 73 calculates the target torque Tm2 according to the following procedure. That is, as shown in the flowchart of FIG. 4, the process proceeds to step S15, and target torque Tm2 of motor generator MG2 is calculated based on the following equation (3). That is, by multiplying the inertia I of the rear wheel rotation system 36 by the target angular acceleration Tω', the target torque Tm2 for eliminating the slip of the rear wheel 30 is calculated. That is, in FIG. 6 described above, when the angular acceleration ω' is "A1a" and the powering torque Tm2' is "T1a", "T1b" is calculated as the target torque Tm2, and the angular acceleration ω' is "A2a" and the power running torque Tm2' is "T2a", "T2b" is calculated as the target torque Tm2. Note that the inertia I of the rear wheel rotation system 36 is the inertia of the rotation system including the rotor 31, the second power transmission path 32, and the rear wheel 30, and is an inertia that is set in advance through experiments, simulations, and the like.
Tm2=I×Tω'...(3)

As shown in the flowchart of FIG. 4, in step S15, when target torque Tm2 of motor generator MG2 is calculated, the process proceeds to step S16, and motor generator MG2 is controlled based on target torque Tm2. As a result, it is possible to reduce the powering torque Tm2' of the motor generator MG2 and eliminate the slippage of the rear wheels 30, so that the rear wheel speed Vrr can be made to match the vehicle speed Vv, and the rear wheel speed Vrr is directly used as the vehicle speed Vv. Can be set. As a result, the vehicle speed Vv can be detected accurately even in situations where slip may occur in the front and rear wheels 20 and 23, or when driving on an uphill or downhill road. Wheel slip control can be appropriately executed.

[Vehicle speed specific control]
As described above, the method for identifying vehicle speed Vv differs depending on whether slip elimination control is executed. Vehicle speed identification control for identifying vehicle speed Vv will be described below. FIG. 7 is a flowchart showing an example of an execution procedure of vehicle speed identification control.

As shown in FIG. 7, in step S20, it is determined whether slip cancellation control is being executed. If it is determined in step S20 that the slip elimination control is being executed, the process proceeds to step S21, where the rear wheel speed Vrr is specified as the vehicle speed Vv. In other words, since the slipping of the rear wheels 30 has been eliminated by the slip elimination control, the rear wheel speed Vrr is directly read as the vehicle speed Vv. That is, with the slip elimination control being executed, the vehicle speed detection unit 74 of the main controller 50 detects the rear wheel speed Vrr as the vehicle speed Vv.

If it is determined in step S20 that the slip elimination control is not being executed, the process proceeds to step S22, where it is determined whether or not the front wheel speed Vft is lower than the rear wheel speed Vrr. If it is determined in step S22 that the front wheel speed Vft is lower than the rear wheel speed Vrr, it is assumed that the lower speed side front wheel speed Vft matches the vehicle speed Vv, so the process proceeds to step S23, and the front wheel speed Vft is lower than the rear wheel speed Vrr. It is specified as vehicle speed Vv. On the other hand, if it is determined in step S22 that the front wheel speed Vft is equal to or higher than the rear wheel speed Vrr, it is assumed that the low speed side rear wheel speed Vrr matches the vehicle speed Vv, so the process proceeds to step S21. Rear wheel speed Vrr is specified as vehicle speed Vv.

[Front wheel slip control and rear wheel slip control (timing chart)]
Next, the execution status of slip control based on slip elimination control will be explained in detail. FIG. 8 is a timing chart showing an example of the execution status of front wheel slip control and rear wheel slip control. In the example shown in the timing chart of FIG. 8, the front and rear driving force distribution ratio is set to 50:50, and the front wheel required driving force Fft and the rear wheel required driving force Frr are equal to each other. . In addition, in the timing chart of FIG. 8, from the viewpoint of clarifying the transition of torque, driving force, speed, etc., even when the lines overlap each other, these lines are shown slightly shifted from each other.

In addition, in FIG. 8, a situation where the front wheel slip control is "ON" is a situation where the execution condition Fa is satisfied and the front wheel slip control is executed, and a situation where the front wheel slip control is "OFF" is a situation where the front wheel slip control is "OFF". This is a situation where Fb is established and front wheel slip control is stopped. Furthermore, a situation in which the rear wheel slip control is "ON" is a situation in which the execution condition Ra is satisfied and the rear wheel slip control is executed, and a situation in which the rear wheel slip control is "OFF" is a situation in which the execution condition Ra is satisfied and the rear wheel slip control is executed. This is a situation in which the following holds true and rear wheel slip control is stopped.

As shown at time t1 in FIG. 8, when the accelerator pedal 60 is depressed and the accelerator opening degree Acc increases (symbol a1), the required front wheel driving force Fft and the required rear wheel driving force Frr increase (symbol b1), Target torques Tm1 and Tm2 of motor generators MG1 and MG2 increase (symbol c1). As a result, the actual driving force Fft' of the front wheels 20 changes in line with the required front wheel driving force Fft, and the actual driving force Frr' of the rear wheels 30 changes in line with the required rear wheel driving force Frr (symbol b1). . Note that the broken line α shown in FIG. 8 indicates the motor torque required to obtain the required driving forces Fft and Frr linked to the accelerator operation.

As shown at time t2 in FIG. 8, when the vehicle 11 enters a low μ road such as a frozen road surface, the front wheels 20 and rear wheels 30 begin to spin, causing the front wheel speed Vft and the rear wheel speed Vrr to deviate from the vehicle speed Vv. and begins to rise (symbol d1). Subsequently, as shown at time t3, when the front wheel speed Vft and the rear wheel speed Vrr further increase apart from the vehicle speed Vv (symbol d2), the slip ratios SLft and SLrr exceed the predetermined threshold value SL1 (symbol e1). , front wheel slip control to suppress the slipping of the front wheels 20 is executed (symbol f1), and rear wheel slip control to suppress the slipping of the rear wheels 30 is executed (symbol g1). In this way, when the front wheel slip control and the rear wheel slip control are executed, the target torques Tm1 and Tm2 of the motor generators MG1 and MG2 are lowered (symbol c2), and the actual driving force Fft' of the front wheels 20 and the rear wheels 30 is reduced. Frr' is lowered (symbol b2).

Here, since front wheel slip control is executed for the motor generator MG1 that drives the front wheels 20, the slip rate SLft of the front wheels 20 is maintained at the target slip rate Sx1 (for example, 10%) (symbol e2). Target torque Tm1 of motor generator MG1 is controlled (symbol c3). On the other hand, regarding the motor generator MG2 that drives the rear wheels 30, since both the front wheels 20 and the rear wheels 30 are spinning, the slip elimination control described above is executed. That is, a target torque Tx1 for eliminating the slip of the rear wheels 30 is set, and the target torque Tm2 is lowered toward this target torque Tx1 (symbol c4). Thereby, as shown at time t4 in FIG. 8, it is possible to eliminate the slippage of the rear wheels 30 (symbol e3), and it is possible to make the rear wheel speed Vrr match the vehicle speed Vv (symbol d3).

In this way, when the rear wheel speed Vrr is made to match the vehicle speed Vv by the slip elimination control, the main controller 50 specifies the rear wheel speed Vrr as the vehicle speed Vv, and uses it as the vehicle speed Vv when executing the front wheel slip control. It will be done. Thereby, the accurately detected vehicle speed Vv can be used for front wheel slip control, so front wheel slip control can be appropriately executed.

Further, after the rear wheel speed Vrr is made to match the vehicle speed Vv by the slip elimination control, the target torque Tm2 of the motor generator MG2 is set based on the following equation (4). That is, in order to set the target torque Tm2 at which the grip state of the rear wheel 30 is maintained, the target torque Tm1 of the motor generator MG1 is multiplied by a predetermined coefficient k1 (for example, 0.9). Torque Tm2 is calculated. In this embodiment, since the target slip rate Sx1 of the front wheels 20 is "10%", in order to control the slip rate SLrr of the rear wheels 30 toward "0%", "0%" is set as the predetermined coefficient k1. .9" is used.
Tm2=Tm1×k1...(4)

Thereby, the motor generator MG2 that drives the rear wheels 30 can be controlled so that the slip ratio SLrr of the rear wheels 30 is maintained at "0%", so the vehicle speed Vv can be continuously detected with high accuracy. In this way, since the vehicle speed Vv can be continuously detected with high accuracy, front wheel slip control can be appropriately executed, and the running stability of the vehicle 11 can be improved.

[Front wheel slip control (flow chart)]
The execution procedure of the front wheel slip control described above will be explained according to a flowchart. FIG. 9 is a flowchart showing an example of the procedure for executing front wheel slip control.

As shown in FIG. 9, in step S30, the slip rate SLft of the front wheels 20 is calculated, and in the subsequent step S31, based on the slip rate SLft of the front wheels 20, etc., it is determined whether the execution condition Fa for front wheel slip control is satisfied. It will be judged. If it is determined in step S31 that the execution condition Fa is satisfied, the process proceeds to step S32 and front wheel slip control is executed. In step S32, target torque Tm1 of motor generator MG1 is controlled so that slip rate SLft of front wheels 20 maintains target slip rate Sx1 (for example, 10%).

Subsequently, in step S33, the slip rate SLft of the front wheels 20 is calculated, and in the subsequent step S34, it is determined based on the slip rate SLft of the front wheels 20, etc., whether or not the stop condition Fb of the front wheel slip control is satisfied. If it is determined in step S34 that the stop condition Fb is satisfied, the process proceeds to step S35, and the front wheel slip control is stopped. In step S35, target torque Tm1 of motor generator MG1 is controlled based on front wheel required driving force Fft.

[Rear wheel slip control (flow chart)]
The execution procedure of the rear wheel slip control described above will be explained according to a flowchart. FIGS. 10 and 11 are flowcharts showing an example of an execution procedure of rear wheel slip control. In the flowcharts of FIGS. 10 and 11, they are connected to each other at points A and connected to each other at points B.

As shown in FIG. 10, in step S40, the slip rate SLrr of the rear wheels 30 is calculated, and in the subsequent step S41, based on the slip rate SLrr of the rear wheels 30, etc., it is determined whether the execution condition Ra of the rear wheel slip control is satisfied. It is determined whether or not. If it is determined in step S41 that the execution condition Ra is satisfied, the process proceeds to step S42, where it is determined whether slip cancellation control is being executed. In step S42, if it is determined that the slip cancellation control is being executed, that is, if the rear wheel speed Vrr is specified as the vehicle speed Vv by the slip cancellation of the rear wheels 30, the process proceeds to step S43, and the motor generator MG2 is activated. Target torque Tm2 is set. In step S43, target torque Tm1 of motor generator MG1 is multiplied by a predetermined coefficient k1 (for example, 0.9) by using equation (4) described above to calculate target torque Tm2 of motor generator MG2.

Subsequently, in step S44, the slip rate SLft of the front wheels 20 is calculated, and in the subsequent step S45, it is determined based on the slip rate SLft of the front wheels 20, etc., whether or not the stop condition Fb of the front wheel slip control is satisfied. That is, since the slip rate SLrr of the rear wheels 30 becomes "0%" due to the slip elimination control, the return to normal control is determined using the stop condition Fb of the front wheel slip control. If it is determined in step S45 that the stop condition Fb is satisfied, the process proceeds to step S46, where the rear wheel slip control is stopped. In step S46, target torque Tm2 of motor generator MG2 is controlled based on rear wheel required driving force Frr.

On the other hand, if it is determined in step S42 that slip elimination control is not being executed, the process proceeds to step S47, where rear wheel slip control is executed. In step S47, target torque Tm2 of motor generator MG2 is controlled so that slip rate SLrr of rear wheels 30 maintains target slip rate Sx1 (for example, 10%). Next, in step S48, the slip rate SLrr of the rear wheels 30 is calculated, and in the subsequent step S49, it is determined based on the slip rate SLrr of the rear wheels 30, etc., whether or not the stop condition Rb of the rear wheel slip control is satisfied. Ru. If it is determined in step S49 that the stop condition Rb is satisfied, the process proceeds to step S50, and the rear wheel slip control is stopped. In step S50, target torque Tm2 of motor generator MG2 is controlled based on rear wheel required driving force Frr.

[Other embodiments]
In the above description, the slip elimination control during deceleration traveling was explained using the flowchart of FIG. 4, but the slip elimination control may be executed during deceleration traveling without being limited to this. In other words, the state in which the rear wheel 30 slips includes not only a state in which the rear wheel 30 slips in the acceleration direction due to the power running torque of the motor generator MG2, but also a state in which the rear wheel 30 slips in the deceleration direction due to the regenerative torque of the motor generator MG2. There is. That is, the state in which the rear wheels 30 slip is not only the state in which the rear wheels 30 spin while the vehicle is running due to depression of the accelerator pedal 60, but also the state in which the rear wheels 30 are locked while the vehicle is running due to the depression of the accelerator pedal 60 being released. There is a condition.

In the following explanation, since various controls are performed during vehicle deceleration, motor torque appears on the regeneration side (-side) opposite to the powering side (+ side). Therefore, the target torques Tm1, Tm2 and powering torques Tm1', Tm2' described above are described as target regenerative torques Tm1, Tm2 and regenerative torques Tm1', Tm2'. Note that the fact that the target regenerative torques Tm1, Tm2 and the regenerative torques Tm1', Tm2' are large means that the target torques Tm1, Tm2 and the power running torques Tm1', Tm2' are large on the negative side.

In addition, since these are various controls during vehicle deceleration, the above-mentioned front wheel required driving force Fft, rear wheel required driving force Frr, and actual driving force Fft', Frr' are braking in the opposite direction to the drive side (+ side). Output to the negative side (- side). Therefore, the front wheel required driving force Fft is written as the front wheel required driving force Fft, the rear wheel required driving force Frr is written as the rear wheel required braking force Frr, and the actual driving forces Fft', Frr' are written as the actual braking force Fft', It is written as Frr'. Note that the fact that front wheel required braking force Fft, rear wheel required braking force Frr, and actual braking force Fft', Frr' are large means that front wheel required driving force Fft, rear wheel required driving force Frr, and actual driving force Fft', Frr' are large. This means that it is large on the negative side.

[Slip control during deceleration driving (timing chart)]
Slip control during deceleration traveling will be explained. FIG. 12 is a timing chart showing an example of the execution status of front wheel slip control and rear wheel slip control during deceleration driving. In the timing chart of FIG. 12, both front wheel slip control and rear wheel slip control are described together. In addition, in FIG. 12, from the viewpoint of clarifying the transition of torque, driving force, etc., even when the lines overlap each other, these lines are shown shifted slightly. Note that the slip ratio SLft of the front wheels 20 is a value calculated using the above-mentioned formula (1), and the slip ratio SLrr of the rear wheels 30 is a value calculated using the above-mentioned formula (2). It is. That is, when the front wheels 20 and the rear wheels 30 are not locked and the front wheel speed Vft and the rear wheel speed Vrr match the vehicle speed Vv, the slip ratios SLft and SLrr are calculated as 0%. On the other hand, if the front wheels 20 and rear wheels 30 lock during deceleration driving and the front wheel speed Vft and rear wheel speed Vrr are lower than the vehicle speed Vv, the slip ratios SLft and SLrr are on the negative side (-side) from 0%. It is calculated as follows.

Front wheel slip control and rear wheel slip control during deceleration driving mean that when the front wheels 20 and rear wheels 30 are locked on a low μ road such as a frozen road surface, the motor torque of motor generators MG1 and MG2 is adjusted to prevent the front wheels 20 and This is control to maintain the rear wheels 30 at a predetermined slip ratio Sx2 (for example, -10%). By executing this slip control, it is possible to avoid excessive locking of the front wheels 20 and the rear wheels 30, thereby improving driving stability on frozen road surfaces and the like. As a condition for executing this slip control, for example, the absolute values of the slip ratios SLft and SLrr exceed a predetermined threshold value SL3. That is, whether or not the slip control execution conditions are satisfied is determined based on the slip ratios SLft and SLrr of the front wheels 20 and the rear wheels 30. Further, as a condition for stopping the slip control, for example, the absolute values of the slip ratios SLft and SLrr are less than a predetermined threshold value SL4.

As shown at time t1 in FIG. 12, when the accelerator opening degree Acc decreases due to release of the accelerator pedal 60, the required front wheel braking force Fft and the required rear wheel braking force Frr increase, and the target regeneration of motor generators MG1 and MG2 increases. Torques Tm1 and Tm2 increase. Then, regenerative torques Tm1' and Tm2' of motor generators MG1 and MG2 increase so as to follow target regenerative torques Tm1 and Tm2, and actual braking forces Fft' and Frr' of front wheels 20 and rear wheels 30 increase.

Subsequently, as shown at time t2, when the actual braking force Fft', Frr' of the front wheels 20 and rear wheels 30 increases and exceeds the road reaction force, the front wheels 20 and rear wheels 30 lock, so that the slip rate SLft increases. , SLrr begin to increase in absolute value. Then, as shown at time t3, when the absolute values of the slip ratios SLft and SLrr exceed the threshold value SL3, front wheel slip control is performed to reduce the target regenerative torques Tm1 and Tm2 in order to suppress locking of the front wheels 20 and rear wheels 30. Rear wheel slip control is executed.

In the front wheel slip control and the rear wheel slip control, the motor generator MG1 is controlled so that the slip rates SLft and SLrr of the front wheels 20 and the rear wheels 30 maintain a target slip rate Sx2 (for example, -10%), which is a predetermined slip rate. , MG2 target regenerative torques Tm1 and Tm2 are controlled. In other words, when the slip ratios SLft and SLrr exceed the target slip ratio Sx2, the target regeneration torques Tm1 and Tm2 are set lower, while when the slip ratios SLft and SLrr are lower than the target slip ratio Sx2, the target regeneration torques Tm1 and Tm2 are set lower. Torques Tm1 and Tm2 are set higher. Thereby, even in a situation where the front wheels 20 and the rear wheels 30 are locked, the slip ratios SLft and SLrr can be maintained at the target slip ratio Sx2, and the running stability of the vehicle 11 can be improved.

That is, even in a situation where the front wheel required braking force Fft and the rear wheel required braking force Frr are set large by releasing the accelerator pedal 60, and the target regenerative torques Tm1 and Tm2 can be set large as shown by the broken line Tx, As shown by arrow α, target regenerative torques Tm1 and Tm2 are set lower. As a result, as shown by the arrow β, the actual braking force Fft', Frr' of the front wheels 20 and rear wheels 30 can be lowered, so it is possible to avoid excessive locking of the front wheels 20 and rear wheels 30, and to reduce the The running stability of the vehicle 11 on the μ road can be improved.

[Slip elimination control during deceleration driving (flow chart)]
FIG. 13 is a flowchart illustrating an example of an execution procedure of slip cancellation control. As shown in FIG. 13, in step S60, it is determined whether or not both the front wheels 20 and the rear wheels 30 are slipping. In step S60, if both the front wheels 20 and the rear wheels 30 are slipping, that is, if both the front wheel speed Vft and the rear wheel speed Vrr deviate from the vehicle speed Vv, the process advances to step S61, and the rear wheels 30 Slip elimination control is started to eliminate the slip.

In step S61, the angular acceleration ω' of the rotor 31 of the motor generator MG2 connected to the rear wheel 30 in slip is detected, and in the subsequent step S62, the rotor 31 of motor generator MG2 connected to the rear wheel 30 in slip is detected. A regenerative torque (torque) Tm2' is detected. That is, in step S61, angular acceleration detection section 70 of main controller 50 calculates angular acceleration ω' generated in the rotor based on the rotational speed of motor generator MG2. In the subsequent step S62, the torque detection unit 71 of the main controller 50 calculates the regenerative torque Tm2' acting on the rotor based on the current supplied to the stator.

Here, FIG. 14 is a diagram showing the relationship between angular acceleration ω' of motor generator MG2 and regenerative torque Tm2'. As shown by arrow A2 in FIG. 14, when the vehicle 11 runs on a high μ road such as a dry road surface, that is, when the vehicle 11 runs without locking the rear wheels 30, the regenerative torque is increased along the characteristic line L2a. As Tm2' increases, angular acceleration ω' gradually increases. Further, as shown by arrows B2, C2, and D2, when the vehicle 11 runs on a low μ road such as a frozen road surface or a packed snow road surface, that is, when the rear wheels 30 are locked due to the magnitude of the regenerative torque Tm2'. In this case, when the regenerative torque Tm2' exceeds a predetermined value, the angular acceleration ω' rapidly increases along the characteristic lines L2b, L2c, and L2d.

That is, when the frictional resistance is small even on a low μ road, when the regenerative torque Tm2' exceeds the predetermined value T4, the rear wheels 30 start to lock and the angular acceleration ω' increases rapidly. Furthermore, when the frictional resistance is moderate even on a low μ road, when the regenerative torque Tm2' exceeds the predetermined value T5, the rear wheels 30 begin to lock and the angular acceleration ω' increases rapidly. Further, when the frictional resistance is large even on a low μ road, when the regenerative torque Tm2' exceeds the predetermined value T6, the rear wheels 30 start to lock and the angular acceleration ω' increases rapidly. Note that since the rear wheels 30 are locked, the slopes of the characteristic lines L2b, L2c, and L2d are hardly affected by the frictional resistance of the road surface, and are substantially constant. Further, in the illustrated example, three characteristic lines L2b, L2c, and L2d are shown, but the present invention is not limited to this, and a large number of characteristic lines can be shown depending on the frictional resistance of the road surface.

As shown in the flowchart of FIG. 13, in step S63, a characteristic line indicating the slip state of the rear wheel 30 is estimated based on the angular acceleration ω' and the regenerative torque Tm2', and in the subsequent step S64, based on the characteristic line, the motor A target angular acceleration Tω' of the generator MG2 is set. The procedure for setting the target angular acceleration Tω' by the target angular acceleration setting section 72 will be described below. Here, FIG. 15 is a diagram similar to FIG. 14, and is a diagram showing the relationship between angular acceleration ω' of motor generator MG2 and regenerative torque Tm2'.

As shown in FIG. 15, when the angular acceleration ω' is "A3a" and the regenerative torque Tm2' is "T3a", it is considered that the rear wheel 30 is locked along the characteristic line L2b. . Therefore, in order to eliminate the slip of the rear wheels 30, it is necessary to lower the negative angular acceleration ω' until it reaches the characteristic line L2a. That is, the slip of the rear wheels 30 can be eliminated by setting the target angular acceleration Tω' to "A3b" and lowering the regenerative torque Tm2' as shown by the arrow X1. Further, for example, if the angular acceleration ω' is "A4a" and the regenerative torque Tm2' is "T4a", it is considered that the rear wheel 30 is locked along the characteristic line L2e shown by the broken line. It will be done. In this case, the slip of the rear wheels 30 can be eliminated by setting the target angular acceleration Tω' to "A2b" and lowering the regenerative torque Tm2' as shown by the arrow X2.

In this way, when the target angular acceleration Tω' for eliminating the slip of the rear wheels 30 is set, the target torque setting unit 73 calculates the target regenerative torque (target torque) Tm2 according to the following procedure. That is, as shown in the flowchart of FIG. 13, the process proceeds to step S65, and target regenerative torque Tm2 of motor generator MG2 is calculated based on the above-mentioned equation (3). That is, by multiplying the inertia I of the rear wheel rotation system 36 by the target angular acceleration Tω', the target regenerative torque Tm2 for eliminating the slip of the rear wheel 30 is calculated. That is, in FIG. 15 described above, when the angular acceleration ω' is "A3a" and the regenerative torque Tm2' is "T3a", "T3b" is calculated as the target regenerative torque Tm2, and the angular acceleration ω When ' is "A4a" and regenerative torque Tm2' is "T4a", "T4b" is calculated as target regenerative torque Tm2.

As shown in the flowchart of FIG. 13, in step S65, when target regenerative torque Tm2 of motor generator MG2 is calculated, the process proceeds to step S66, and motor generator MG2 is controlled based on target regenerative torque Tm2. As a result, it is possible to reduce the regenerative torque Tm2' of the motor generator MG2 and release the lock of the rear wheels 30, so that the rear wheel speed Vrr can be made to match the vehicle speed Vv, and the rear wheel speed Vrr is directly used as the vehicle speed Vv. Can be set. Thereby, the vehicle speed Vv can be detected with high accuracy, so that front wheel slip control and rear wheel slip control, which will be described later, can be appropriately executed.

[Front wheel slip control and rear wheel slip control during deceleration driving (timing chart)]
Next, the execution status of slip control based on slip elimination control will be explained in detail. FIG. 16 is a timing chart showing an example of the execution status of front wheel slip control and rear wheel slip control. In the example shown in the timing chart of FIG. 16, the front and rear braking force distribution ratio is set to 50:50, and the front wheel required braking force Fft and the rear wheel required braking force Frr are equal to each other. . Further, in the timing chart of FIG. 16, from the viewpoint of clarifying the transition of torque, braking force, speed, etc., even when the lines overlap each other, these lines are shown slightly shifted from each other.

As shown at time t1 in FIG. 16, when the accelerator pedal 60 is released and the accelerator opening degree Acc decreases (symbol a1), the front wheel required braking force Fft and the rear wheel required braking force Frr increase (symbol b1). ), target regenerative torques Tm1 and Tm2 of motor generators MG1 and MG2 increase (symbol c1). As a result, the actual braking force Fft' of the front wheels 20 changes in line with the front wheel required braking force Fft, and the actual braking force Frr' of the rear wheels 30 changes in line with the rear wheel required braking force Frr (symbol b1). . Note that the broken line α shown in FIG. 16 indicates the motor torque required to obtain the required braking forces Fft and Frr linked to the accelerator operation.

As shown at time t2 in FIG. 16, when the vehicle 11 enters a low μ road such as a frozen road surface, the front wheels 20 and rear wheels 30 begin to lock, so that the front wheel speed Vft and the rear wheel speed Vrr deviate from the vehicle speed Vv. and begins to decrease (symbol d1). Subsequently, as shown at time t3, when the front wheel speed Vft and the rear wheel speed Vrr further decrease away from the vehicle speed Vv (symbol d2), the absolute values of the slip ratios SLft and SLrr exceed a predetermined threshold value SL3 ( code e1), front wheel slip control to suppress locking of the front wheels 20 is executed (code f1), and rear wheel slip control to suppress locking of the rear wheels 30 is executed (code g1). In this way, when the front wheel slip control and the rear wheel slip control are executed, the target regenerative torques Tm1 and Tm2 of the motor generators MG1 and MG2 are lowered (symbol c2), and the actual braking force Fft' of the front wheels 20 and the rear wheels 30 is reduced. , Frr' are lowered (symbol b2).

Here, since front wheel slip control is executed for the motor generator MG1 that drives the front wheels 20, the slip rate SLft of the front wheels 20 is maintained at the target slip rate Sx2 (for example, -10%) (symbol e2). , target regenerative torque Tm1 of motor generator MG1 is controlled (symbol c3). On the other hand, regarding the motor generator MG2 that drives the rear wheels 30, since both the front wheels 20 and the rear wheels 30 are locked, the above-described slip elimination control is executed. That is, a target regenerative torque Tx2 for releasing the lock of the rear wheel 30 is set, and the target regenerative torque Tm2 is lowered toward this target regenerative torque Tx2 (symbol c4). As a result, as shown at time t4 in FIG. 16, the lock of the rear wheels 30 can be released (symbol e3), and the rear wheel speed Vrr can be made to match the vehicle speed Vv (symbol d3).

In this way, when the rear wheel speed Vrr is made to match the vehicle speed Vv by the slip elimination control, the main controller 50 specifies the rear wheel speed Vrr as the vehicle speed Vv, and uses it as the vehicle speed Vv when executing the front wheel slip control. It will be done. Thereby, the accurately detected vehicle speed Vv can be used for front wheel slip control, so front wheel slip control can be appropriately executed.

Further, after the rear wheel speed Vrr is made to match the vehicle speed Vv by the slip elimination control, the target regenerative torque Tm2 of the motor generator MG2 is set based on the above-mentioned equation (4). That is, in order to set the target regenerative torque Tm2 at which the grip state of the rear wheel 30 is maintained, the target regenerative torque Tm1 of the motor generator MG1 is multiplied by a predetermined coefficient k1 (for example, 0.9). The target regenerative torque Tm2 is calculated. In this embodiment, since the target slip rate Sx2 of the front wheels 20 is "-10%", in order to control the slip rate SLrr of the rear wheels 30 toward "0%", " 0.9'' is used.

Thereby, the motor generator MG2 that drives the rear wheels 30 can be controlled so that the slip ratio SLrr of the rear wheels 30 is maintained at "0%", so the vehicle speed Vv can be continuously detected with high accuracy. In this way, since the vehicle speed Vv can be continuously detected with high accuracy, front wheel slip control can be appropriately executed, and the running stability of the vehicle 11 can be improved.

It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit thereof. In the above description, an electric vehicle without an engine is exemplified as the vehicle 11 to which the vehicle control device 10 is applied; however, the present invention is not limited to this, and a hybrid vehicle having an engine as a power source may also be used. Alternatively, the vehicle may have only an engine as a power source. In addition, in the above explanation, front wheel slip control, rear wheel slip control, and slip elimination control are executed, but the present invention is not limited to this, and slip elimination control is performed without executing front wheel slip control or rear wheel slip control. may be executed. In other words, even when slip elimination control is executed without executing slip control, it is possible to accurately detect vehicle speed Vv. Further, the vehicle to which the vehicle control device 10 is applied is not limited to the all-wheel drive vehicle described above, and may be a front-wheel drive vehicle or a rear-wheel drive vehicle.

In the above description, the first drive wheel on one of the front and rear wheels is the front wheel 20, and the second drive wheel on the other front and rear wheel is the rear wheel 30. In the slip release control, the motor generator MG2 is controlled to drive the rear wheel 30. Although the slip is eliminated, it is not limited to this. That is, by performing slip release control on the front wheels 20, motor generator MG1 may be controlled to eliminate the slip of the front wheels 20. Thereby, the front wheel speed Vft can be made to match the vehicle speed Vv, and the front wheel speed Vft can be used as it is as the vehicle speed Vv. In this case, the angular acceleration ω' and torque Tm1' of the rotor 21 are detected with the front wheel 20 slipping, and the goal is to eliminate the slip of the front wheel 20 based on these angular acceleration ω' and torque Tm1'. The angular acceleration Tω' is set. Then, target torque Tm1 is calculated by multiplying inertia I of front wheel rotation system 26 by target angular acceleration Tω', and motor generator MG1 is controlled based on this target torque Tm1. In this way, when performing slip release control on the front wheels 20, the rear wheels 30 function as the first drive wheels, the motor generator MG2 functions as the first motor, and the front wheels 20 function as the drive wheels or the second drive wheels. It functions as a driving wheel, and motor generator MG1 functions as a power source, a motor, or a second motor.

Further, when calculating the angular acceleration generated in the rotor 31 of the motor generator MG2, it is possible to calculate using the rotational speed of the rotor 31 detected by the rotor rotation sensor 67, but the calculation is not limited to this. Instead, for example, the angular acceleration generated in the rotor 31 may be calculated using the rear wheel speed Vrr, which is the rotation speed of the rear wheel rotation system 36. Similarly, when calculating the angular acceleration generated in the rotor 21 of the motor generator MG1, it is possible to calculate using the rotational speed of the rotor 21 detected by the rotor rotation sensor 66, but the calculation is not limited to this. For example, the angular acceleration generated in the rotor 21 may be calculated using the front wheel speed Vft, which is the rotation speed of the front wheel rotation system 26.

Although the illustrated vehicle 11 has one motor generator MG1 driving two front wheels 20 and one motor generator MG2 driving two rear wheels 30, the present invention is not limited to this. For example, by installing four motor generators, one motor generator may drive one wheel. Furthermore, in the above description, the main controller 50 includes a front wheel slip determination section 55, a front wheel slip control section 56, a rear wheel slip determination section 57, a rear wheel slip control section 58, an angular acceleration detection section 70, a torque detection section 71, a target Although it is made to function as the angular acceleration setting section 72, the target torque setting section 73, and the vehicle speed detection section 74, the present invention is not limited thereto. For example, using another controller or a plurality of controllers, a front wheel slip determination section 55, a front wheel slip control section 56, a rear wheel slip determination section 57, a rear wheel slip control section 58, an angular acceleration detection section 70, a torque detection section 71, A target angular acceleration setting section 72, a target torque setting section 73, and a vehicle speed detection section 74 may be configured.

In the above description, slip control is executed based on the slip rates SLft and SLrr, but the slip control is not limited to this. For example, the rotational speed difference between the vehicle speed Vv and the front wheel speed Vft may be used as a numerical value indicating the slip state of the front wheels 20, and the rotational speed difference between the vehicle speed Vv and the rear wheel speed Vrr may be used as a numerical value indicating the slip state of the rear wheels 30. A speed difference may also be used. In addition, in the above explanation, the slip rates SLft and SLrr are controlled to the common target slip rates Sx1 and Sx2 in both the front wheel slip control and the rear wheel slip control, but the front wheel slip rate is not limited to this. The target slip rate used in slip control and the target slip rate used in rear wheel slip control may be different from each other.

In the above description, the execution condition for slip control is that the absolute values of the slip rates SLft and SLrr exceed the predetermined thresholds SL1 and SL3, and the condition for stopping the slip control is that the absolute values of the slip rates SLft and SLrr are Although being below the predetermined thresholds SL2 and SL4 is illustrated, the present invention is not limited to this. For example, the conditions for executing slip control during acceleration traveling may be that the accelerator opening degree Acc exceeds a predetermined threshold value and that the slip ratios SLft and SLrr exceed a predetermined threshold value SL1. In addition, as a condition for stopping the slip control during accelerated driving, it is also possible to adopt that the accelerator opening degree Acc is less than a predetermined threshold value, or that the slip ratios SLft and SLrr are less than a predetermined threshold value SL2. Further, when the slip release control is not performed, the vehicle speed Vv may be calculated from the acceleration of the vehicle 11, etc., or may be calculated from the position signal of a GPS (Global Positioning System).

10 Vehicle control device 11 Vehicle 20 Front wheel (first drive wheel)
21 Rotor (first rotor)
22 First power transmission path 30 Rear wheel (drive wheel, second drive wheel)
31 Rotor (rotating body, second rotor)
32 Second power transmission path 36 Rear wheel rotation system (rotation system)
55 Front wheel slip determination section (slip determination section)
56 Front wheel slip control section (slip control section)
70 Angular acceleration detection section 71 Torque detection section 72 Target angular acceleration setting section 73 Target torque setting section 74 Vehicle speed detection section MG1 Motor generator (first motor)
MG2 motor generator (power source, motor, second motor)
Vv Vehicle speed (vehicle movement speed)
Vrr Rear wheel speed (rotational speed of drive wheels)
Tm2 Target torque, target regeneration torque (target torque)
Tm2' Powering torque, regenerative torque (torque)
ω' Angular acceleration Tω' Target angular acceleration I Inertia Fa Execution conditions

Claims (7)

A vehicle control device installed in a vehicle,
a power source including a rotating body connected to a drive wheel via a power transmission path;
an angular acceleration detection unit that detects angular acceleration generated in the rotating body when the drive wheel is in a slip state;
a torque detection unit that detects torque acting on the rotating body when the drive wheel is in a slip state;
a target angular acceleration setting unit that sets a target angular acceleration of the rotating body at which slip of the driving wheels is eliminated based on the angular acceleration and the torque;
a target torque setting unit that multiplies the inertia of a rotating system including the drive wheels, the power transmission path, and the rotating body by the target angular acceleration to set a target torque of the rotating body;
a vehicle speed detection unit that detects a rotational speed of the driving wheels as a moving speed of the vehicle under a state in which the power source is controlled based on the target torque;
A vehicle control device having: The vehicle control device according to claim 1,
the power source is a motor;
Vehicle control device. The vehicle control device according to claim 2,
The state in which the drive wheel slips is a state in which the drive wheel slips due to the power running torque of the motor, or a state in which the drive wheel slips due to regenerative torque of the motor.
Vehicle control device. A vehicle control device installed in a vehicle,
a first motor including a first rotor connected to one of the front and rear first drive wheels via a first power transmission path;
a second motor including a second rotor connected to the other front and rear second drive wheels via a second power transmission path;
a slip determination unit that determines whether a slip control execution condition is satisfied based on the slip state of the first drive wheel;
a slip control unit that controls the first motor and maintains the first drive wheel at a predetermined slip ratio when a condition for executing the slip control is satisfied;
an angular acceleration detection unit that detects angular acceleration generated in the second rotor when the second drive wheel is in a slip state;
a torque detection unit that detects torque acting on the second rotor when the second drive wheel is in a slip state;
a target angular acceleration setting unit that sets a target angular acceleration of the second rotor at which slip of the second drive wheel is eliminated based on the angular acceleration and the torque;
a target torque setting unit that multiplies the inertia of a rotation system including the second drive wheel, the second power transmission path, and the second rotor by the target angular acceleration to set a target torque of the second rotor;
a vehicle speed detection unit that detects the rotational speed of the second drive wheel as the moving speed of the vehicle while the second motor is controlled based on the target torque;
has
The slip control section controls the slip rate of the first drive wheel used for the slip control based on the rotation speed of the first drive wheel and the rotation speed of the second drive wheel, which is the moving speed of the vehicle. calculate,
Vehicle control device. The vehicle control device according to claim 4,
The state in which the second drive wheel slips is a state in which the second drive wheel slips due to the power running torque of the second motor, or a state in which the second drive wheel slips due to regenerative torque of the second motor. ,
Vehicle control device. The vehicle control device according to claim 4 or 5,
The first driving wheel is a front wheel, and the second driving wheel is a rear wheel.
Vehicle control device. The vehicle control device according to claim 4 or 5,
The first driving wheel is a rear wheel, and the second driving wheel is a front wheel.
Vehicle control device.

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