JP7079111B2 - Vehicle travel control device - Google Patents

Description

The present invention relates to a vehicle travel control device, and more particularly to suppression of a slip state.

Patent Document 1 describes a power control device for an electric vehicle that prevents torque switching of a motor from occurring due to a sudden change in the motor rotation speed when the drive wheels slip or lock. That is, in an electric vehicle equipped with a plurality of motors, the required output calculation means calculates the required travel output according to the driving conditions detected by the traveling condition detecting means, and the shared output to be shared by each motor in the shared output setting means. To set. Normally, the above-mentioned shared output is set each time the traveling condition is detected, and the command means outputs a command signal to each motor based on this. When the abnormality detecting means detects an abnormal state of the rotation speed of the motor, the state holding means does not set a new shared output and keeps the output of the command signal to the motor in the previous state during the abnormal state. .. As a result, even if the motor rotation speed suddenly changes due to tire slip or the like, a stable driving state is maintained without immediately changing the shared output.

Japanese Unexamined Patent Publication No. 7-143618

When the motor rotation speed changes suddenly, the slip ratio increases and the stability of the vehicle deteriorates, so it is necessary to immediately suppress the slip. Since the signal output is maintained in the previous state, there is a problem in terms of running stability.

An object of the present invention is to provide a technique capable of effectively suppressing a slip state.

The present invention includes an operation amount detecting means for detecting the operation amount of the vehicle, a vehicle state detecting means for detecting at least the vehicle speed of the vehicle, and a motor state detecting means for detecting at least the motor rotation speed of the motor for driving the vehicle. The target vehicle speed calculation means for calculating the target vehicle speed of the vehicle based on the operation amount and the vehicle speed, and the slip ratio of the vehicle calculated based on the vehicle speed and the motor rotation speed are the maximum at which the tire generation force of the vehicle is stable. The motor is provided with a control means for executing target vehicle speed tracking control that follows the target vehicle speed when the slip ratio is within, and executing the slip suppression control instead of the target vehicle speed tracking control when the maximum slip ratio is exceeded. Consists of a first motor and a second motor, the first motor being connected to the sun gear of the planetary gear, the second motor being connected to the ring gear of the planetary gear, and the carrier of the planetary gear being of the vehicle. Connected to the output shaft, the control means minimizes the change in the rotation speeds of the first motor and the second motor for keeping the slip ratio within the maximum slip ratio as the slip suppression control. It is a vehicle traveling control device characterized by controlling.

In yet another embodiment of the invention, the control means is
N1: Rotational speed of the first motor N2: Rotational speed of the second motor Np: Output shaft rotational speed Nt: Tire rotational speed Gr: Differential gear ratio R: Tire radius V: Vehicle speed ρ: Planetary gear ratio S *: Maximum slip ratio g1, g2: Weight coefficient u1: Change in rotation speed of the first motor u2: Change in rotation speed of the second motor
As an evaluation function
J1 = min {g1 ・ u1 ² + g2 ・ u2 ² }
And as a constraint,
(N1 + u1) + (1 / ρ) ・ (N2 + u2) --f (S *) = 0
However, f (S *) = (1 + ρ) ・ Gr ・ V / (ρ ・ R ・ (1-S *))
Control to meet.

Further, the present invention includes an operation amount detecting means for detecting the operation amount of the vehicle, a vehicle state detecting means for detecting at least the vehicle speed of the vehicle, and a motor state detecting means for detecting at least the motor rotation speed of the motor for driving the vehicle. The target vehicle speed calculation means for calculating the target vehicle speed of the vehicle based on the operation amount and the vehicle speed, and the slip ratio of the vehicle calculated based on the vehicle speed and the motor rotation speed are stable in the tire generation force of the vehicle. A control means for executing target vehicle speed tracking control that follows the target vehicle speed within the maximum slip ratio, and performing slip suppression control instead of the target vehicle speed tracking control when the maximum slip ratio is exceeded. The motor comprises a first motor and a second motor, the first motor is connected to the sun gear of the planetary gear, the second motor is connected to the ring gear of the planetary gear, and the carrier of the planetary gear is , Connected to the output shaft of the vehicle, the control means controls the slip suppression control so that the arrival time for keeping the slip ratio within the maximum slip ratio is minimized.

In yet another embodiment of the invention,
N1: First motor rotation speed N2: Second motor rotation speed Np: Output shaft rotation speed Nt: Tire rotation speed Gr: Differential gear ratio R: Tire radius V: Vehicle speed ρ: Planetary gear ratio S *: Maximum slip ratio u1: Change in the rotation speed of the first motor u2: Change in the rotation speed of the second motor du1: Response speed of the first motor du2: Response speed of the second motor
As an evaluation function
J2 = min {(u1 / du1) ² + (u2 / du2) ² }
And as a constraint,
(N1 + u1) + (1 / ρ) ・ (N2 + u2) --f (S *) = 0
However, f (S *) = (1 + ρ) ・ Gr ・ V / (ρ ・ R ・ (1-S *))
Control to meet.

According to the present invention, since the target vehicle speed control and the slip suppression control are selectively switched and controlled by using the slip ratio, it is possible to control so as not to enter the slip state and when the slip state is assumed. Can also quickly suppress the slip state. Further, according to the present invention, the slip state can be efficiently suppressed by coordinating control of the first motor and the second motor.

It is a block diagram of the configuration of an embodiment. It is a collinear diagram of the drive system of an embodiment. It is a graph which shows the relationship between a slip ratio and a tire generation force. It is a processing flowchart of an embodiment. It is a detailed flowchart of the slip suppression control of embodiment. It is a μ characteristic diagram in a simulation. It is a simulation result of the target vehicle speed follow-up control (high μ road). It is a simulation result of the target vehicle speed follow-up control (low μ road). This is the simulation result of target vehicle speed tracking control and slip suppression control (low μ road).

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

<Overall configuration>
FIG. 1 shows a block diagram of a vehicle traveling control device according to the present embodiment. The vehicle travel control device includes an operation amount detection means 10, a target derivation means 12, a vehicle state detection means 14, a motor state detection means 16, an optimum control means 18, a slip determination means 20, a slip suppression control means 22, and a control amount determination means. 24 and a motor control means 26 are provided.

The operation amount detecting means 10 detects the driver operation amount such as the accelerator opening degree. The operation amount detecting means 10 outputs the detected driver operation amount to the target derivation means 12.

The vehicle state detecting means 14 detects the vehicle speed of the vehicle from the driven wheel rotation speed and the like. The vehicle state detecting means 14 outputs the detected vehicle state, that is, the vehicle speed, to the target derivation means 12, the optimum control means 18, the slip determination means 20, and the slip suppression control means 22.

The target derivation means 12 calculates the target speed of the vehicle using the driver operation amount from the operation amount detection means 10 and the vehicle speed from the vehicle state detection means 14. The target derivation means 12 outputs the calculated target speed of the vehicle to the optimum control means 18.

The motor state detecting means 16 detects the motor rotation speed of the vehicle motor. The motor state detecting means 16 outputs the detected motor rotation speed to the optimum control means 18, the slip determination means 20, and the slip suppression control means 22.

The optimum control means 18 uses the target speed calculated by the target derivation means 12, the vehicle speed from the vehicle state detecting means 14, and the motor rotation speed from the motor state detecting means 16, and the target rotation of the motor for which the efficiency is optimized is optimized. Calculate control targets such as number and torque. The optimum control means 18 outputs the calculated control target, for example, the target rotation speed, to the control amount determining means 24.

The slip determining means 20 calculates the slip state of the tire by using the vehicle speed from the vehicle state detecting means 14 and the motor rotation speed from the motor state detecting means 16. The details of the slip state calculation will be described later. The slip determining means 20 outputs the calculated slip state to the control amount determining means 24.

The slip suppression control means 22 uses the vehicle speed from the vehicle state detecting means 14 and the motor rotation speed from the motor state detecting means 16 to minimize the amount of change in the motor speed so as to be within the target slip rate. Calculate the motor target rotation speed to keep the speed within the target. The calculation of the motor target rotation speed will also be described later. The slip suppression control means 22 outputs the calculated motor target rotation speed to the control amount determining means 24.

The control amount determining means 24 selects either the target rotation speed which is the output of the optimum control means 18 or the target rotation speed which is the output of the slip suppression control means 22 according to the slip state, and controls the target rotation speed by the motor. Output to means 26.

The motor control means 26 controls the motor so as to reach the target rotation speed, which is the output of the control amount determining means 24.

Specifically, the operation amount detecting means 10 is composed of an accelerator opening degree sensor, the vehicle state detecting means 14 is composed of a vehicle speed sensor, and the motor state detecting means 16 is composed of a rotation speed sensor. Further, the target derivation means 12, the optimum control means 18, the slip determination means 20, the slip suppression control means 22, and the control amount determination means 24 are composed of an electronic control unit (ECU) including a processor, a memory, and an input / output interface. The motor control means 26 may be composed of a driver circuit that supplies drive power to the motor. The processor of the ECU realizes the target derivation means 12, the optimum control means 18, the slip determination means 20, the slip suppression control means 22, and the control amount determining means 24 by reading and executing the processing program stored in the program memory. do. An example of the processing content in the processor is as follows.
・ Calculate the target vehicle speed using the operation amount and vehicle speed ・ Calculate the control amount to follow the target vehicle speed using the vehicle speed, target vehicle speed and motor rotation speed ・ Calculate the slip ratio using the vehicle speed and motor rotation speed・ Compare the calculated slip rate with the maximum slip rate to determine whether the slip rate exceeds the maximum slip rate. ・ If the calculated slip rate is within the maximum slip rate, execute control to follow the target vehicle speed. If the maximum slip ratio is exceeded, slip suppression control is executed. ・ The evaluation function for slip suppression control is calculated and the evaluation function value is minimized.

FIG. 2 shows a collinear diagram of the drive system in the embodiment. A motor is connected to each of the sun gear and the ring gear of the planetary gear (the motor connected to the sun gear is referred to as a motor 1 and the motor connected to the ring gear is referred to as a motor 2), and the output shaft is connected to the carrier.
N1: Motor rotation speed N2: Motor 2 rotation speed Np: Output shaft rotation speed Nt: Tire rotation speed Gr: Def gear (differential gear) ratio R: Tire radius V: Vehicle speed ρ: Planetary gear ratio
Np = Gr ・ Nt
Np = ρ / (1 + ρ) ・ N1 + 1 / (1 + ρ) ・ N2
There is a relationship.

Next, the slip determination in the slip determination means 20 will be described.

FIG. 3 shows the relationship between the slip ratio and the tire generating force. Generally, it is known that when the slip ratio is S * or higher, the inclination of the tire generating force is reversed and the tire becomes unstable. Therefore, it is desirable to keep the slip ratio within S * during driving. To satisfy this,
S *: The maximum slip ratio may be controlled so as to always satisfy the following equation.
(Np --G ・ V / R) / (Np) ≦ S * ・ ・ ・ (1)

From the above equation, the output shaft rotation speed Np needs to satisfy the following equation.
Np ≤ Gr ・ V / (R ・ (1-S *)) ・ ・ ・ (2)
Therefore, the rotation speeds N1 and N2 of the motor 1 and the motor 2 need to be controlled so as to satisfy the following equation.
ρ / (1 + ρ) ・ N1 + 1 / (1 + ρ) ・ N2 ≤ Gr ・ V / (R ・ (1-S *))
N1 + (1 / ρ) ・ N2 ≦ (1 + ρ) ・ Gr ・ V / (ρ ・ R ・ (1-S *)) ・ ・ ・ (3)

The left side of (3) is calculated for the current or target motor rotation speeds N1 and N2. Next, the right side of the equation (3) is calculated from the current vehicle speed V (or estimated speed) using a predetermined maximum slip ratio S *.

Then, from the obtained values of both, it is determined whether or not the inequality sign of the equation (3) is satisfied, and if it is satisfied, it can be determined as a stable region, and if it is not satisfied, it is determined as an unstable region. Slip determination is realized by repeatedly executing this at predetermined control cycles. The slip determination means 20 determines whether or not the equation (3) is satisfied, and outputs the determination result to the control amount determination means 24.

When the determination result from the slip determination means 20 satisfies the equation (3), that is, it is determined that the control amount determination means 24 is in the stable region, the control amount determining means 24 selects the target rotation speed from the optimum control means 18. On the other hand, when it is determined that the determination result does not satisfy the equation (3), that is, it is in the unstable region, the target rotation speed from the slip suppression control means 22 is selected.

<Slip suppression control>
Next, the slip suppression control in the slip suppression control means 22 will be described.

The target rotation speeds for preventing the motor rotation speed N1 of the motor 1 and the motor rotation speed N2 of the motor 2 from slipping are set to N1 + u1 and N2 + u2, respectively. By minimizing the change in rotation speed (u1, u2), the energy required for correction can be minimized, that is, the cooperative control efficiency can be optimized.

Therefore, u1 and u2 that satisfy the following evaluation function (4) and constraint condition (5) are derived as follows.
Evaluation: J1 = min {g1 ・ u1 ² + g2 ・ u2 ² } ・ ・ ・ (4)
Constraints: (N1 + u1) + (1 / ρ) ・ (N2 + u2) --f (S *) = 0 ・ ・ ・ (5)
However, f (S *) = (1 + ρ) ・ Gr ・ V / (ρ ・ R ・ (1-S *))

Here, g1 and g2 are weight constants. f (S *) = (1 + ρ) ・ Gr ・ V / (ρ ・ R ・ (1-S *)) corresponds to the right side of equation (3), and the constraint is the target rotation speed. It is a condition for the equation (3) to be established as an equation in N1 + u1 and N2 + u2. This means that if the left side of the equation (3) is the slip ratio of the vehicle, the slip ratio becomes equal to the maximum slip ratio.

Assuming that the Lagrange multiplier is λ, the optimization problem of the above equation is replaced with the problem of minimizing the evaluation function JJ1 of the following equation.
JJ1 = g1 ・ u1 ² + g2 ・ u2 ² + λ ・ ((N1 + u1) + (1 / ρ) ・ (N2 + u2) --f (S *)) ・ ・ ・ (6)

Taking the partial derivative of the above equation,
∂JJ1 / u1 = 2 ・ g1 ・ u1 + λ = 0 ⇒ u1 = --λ / (2 ・ g1) ・ ・ ・ (7)
∂JJ1 / u2 = 2 ・ g2 ・ u2 + λ / ρ = 0 ⇒ u2 = --λ / (2 ・ g2 ・ ρ) ・ ・ ・ (8)
Will be. Substituting the obtained u1 and u2 into the constraint condition (5) gives the following equation.
(N1 --λ / (2 ・ g1)) + (1 / ρ) ・ (N2 --λ / (2 ・ g2 ・ ρ)) --f (S *) = 0

Solving this for λ gives the following equation.
λ = (2 ・ g1 ・ g2 ・ ρ ² ) (N1 + (1 / ρ) ・ N2 --f (S *)) / (g2 ・ ρ ² + g1) ・ ・ ・ (9)
By substituting this λ into the equations (7) and (8), the target rotation speeds N1 and N2 are obtained.
u1 =-(g2 ・ ρ ² ) ・ (N1 + (1 / ρ) ・ N2 --f (S *)) / (g2 ・ ρ ² + g1) ・ ・ ・ (10)
u2 =-(g1 ・ ρ) ・ (N1 + (1 / ρ) ・ N2 --f (S *)) / (g2 ・ ρ ² + g1) ・ ・ ・ (11)

Since it can be calculated in the form of a function like the above equation, it can be easily calculated even with a small calculation load and a fast cycle.

On the other hand, the time to reach the target value as shown in the following equation (12) can be similarly calculated as an evaluation function. Here, du1 and du2 are values corresponding to the response speed of each motor.
Evaluation: J2 = min {(u1 / du1) ² + (u2 / du2) ² } ・ ・ ・ (12)
Constraints: (N1 + u1) + (1 / ρ) ・ (N2 + u2) --f (S *) = 0 ・ ・ ・ (13)

By performing the same calculation as above, u1 and u2 can be obtained as shown in the following equation.
u1 = --ρ ²・ du1 ・ (N1 + (1 / ρ) ・ N2 --f (S *)) / (du1 ・ ρ ² + du2) ・ ・ ・ (14)
u2 = --ρ ・ du2 ・ (N1 + (1 / ρ) ・ N2 --f (S *)) / (du1 ・ ρ ² + du2) ・ ・ ・ (15)

By using such an evaluation function, it is possible to control the slip state to be suppressed quickly.

<Process flow chart>
FIG. 4 shows a processing flowchart of the present embodiment. This process is repeatedly executed in a predetermined control cycle.

First, the operation amount detecting means 10 detects the driver operation amount, the vehicle state detecting means 14 detects the vehicle speed V, and the motor state detecting means 16 detects the motor rotation speeds N1 and N2 of each of the motors 1 and 2. S101).

Next, the target derivation means 12 calculates the target vehicle speed Vr using the detected driver operation amount and the vehicle speed V (S102).

Next, the slip determination means 20 calculates the output shaft (pera shaft) rotation speed Np (S103). The output shaft rotation speed Np is as described above.
Np = ρ / (1 + ρ) ・ N1 + 1 / (1 + ρ) ・ N2
Is calculated by.

Next, the slip determination means 20 calculates the slip ratio Sc (S104). The slip ratio Sc is
Sc = (Np --G ・ V / R) / (Np) ・ ・ ・ (16)
It is calculated by.

This slip ratio Sc corresponds to the left side of the equation (1).

Next, the slip determination means 20 compares the calculated slip ratio Sc with the maximum slip ratio S * (S105). That is, it is determined whether or not Sc ≦ S *. Needless to say, in this determination process, it may be determined whether or not (Sc—S *) ≦ 0. The slip determination means 20 outputs the determination result to the control amount determination means 24.

When Sc ≦ S *, the control amount determining means 24 selects the control target from the optimum control means 18 and executes the target vehicle speed tracking control (S106). On the other hand, when Sc> S *, the control amount determining means 24 selects the control target from the slip suppression control means 22 and executes the slip suppression control (S107).

In the target vehicle speed follow-up control (S106), the target torques of the motor 1 and the motor 2 for which the efficiency is optimized are controlled. Specifically, for example, the motor 1 is controlled by integration.
dT1 / dt = K1 ・ (Gr ・ Vr / R-Np) ・ ・ ・ (17)
Controlled by. here,
T1: Control amount (torque) of motor 1
K1: Gain. In addition, the motor 2 is controlled proportionally.
T2 = K2 ・ (N1-N2) ・ ・ ・ (18)
Controlled by. here,
T2: Control amount (torque) of motor 2
K2: Gain.

In the slip suppression control (S107), the rotation speed change u1 and u2 for preventing N1 and N2 from slipping are controlled to be minimized.

FIG. 5 shows a processing flowchart of slip suppression control.

The slip suppression control means 22 estimates the torque (S201). Torque Tp is
Tpe (k) = (1 + ρ) ・ (-I1 ・ N1 (・) (k-1) + T1 (k-1)) ・ ・ ・ (19)
Is calculated by. Here, N1 (.) Indicates the time derivative of the motor rotation speed N1 of the motor 1.

Next, the target speed change amount of the motor 1 and the motor 2 is calculated (S202). The target speed change amount is coordinated and controlled by calculating the speed change amounts u1 and u2 that satisfy the constraint conditions with the evaluation function. The evaluation condition minimizes the evaluation function, and the constraint condition is Sc-S * = 0. As the evaluation function, either an evaluation function such as Eq. (4) or an evaluation function such as Eq. (12) can be used. Specifically, if you select equation (4),
u1 =-(g2 ・ ρ ² ) ・ (N1 + (1 / ρ) ・ N2 --f (S *)) / (g2 ・ ρ ² + g1) ・ ・ ・ (20)
u2 =-(g1 ・ ρ) ・ (N1 + (1 / ρ) ・ N2 --f (S *)) / (g2 ・ ρ ² + g1) ・ ・ ・ (21)
Is calculated as. Here, g1 and g2 are weights. These equations are the same as the equations (10) and (11).

Next, the motor torques of the motor 1 and the motor 2 are calculated (S203). Motor torque is
T1 = (I1 / dT) ・ u1 + (1 / (1 + ρ) ・ Tpe) ・ ・ ・ (22)
T2 = (I2 / dT) ・ u2 + (ρ / (1 + ρ) ・ Tpe) ・ ・ ・ (23)
Is calculated by.

<Simulation>
The inventors have executed a computer simulation in order to confirm the effectiveness of the control method of the present embodiment.

FIG. 6 shows the μ characteristics used in the simulation. In the figure, the horizontal axis indicates the slip ratio, and the vertical axis indicates μ between the road surface and the tire. Two road surface conditions, a high μ road and a low μ road, were set, and running conditions for accelerating from 20 km / h to 40 km / h were set.

7, 8 and 9 show the simulation results.

FIG. 7 shows the result when the vehicle travels on a high μ road with the target vehicle speed tracking control (S106). FIG. 7A shows a time change of the vehicle speed, and shows how the vehicle speed (indicated by the solid line in the figure) follows the target vehicle speed (indicated by the dotted line in the figure). FIG. 7B shows a time change of the rotation speed, in which the rotation speed N1 of the motor 1 follows the target rotation speed (corresponding to a vehicle speed of 40 km / h) by integral control, and the rotation speed N2 of the motor 2 is proportionally controlled. The state of following the rotation speed N1 is shown. FIG. 7 (c) shows a time change of the slip ratio, and since it is a high μ path, it is shown that the slip ratio is controlled within the maximum slip ratio (0.2).

FIG. 8 shows the result when the vehicle travels on a low μ road with the target vehicle speed tracking control (S106). FIG. 8A shows a time change of the vehicle speed, and it is shown that the vehicle speed (solid line) does not easily follow the target vehicle speed (dotted line) because μ is low, that is, the road surface is slippery. FIG. 8B shows a time change of the rotation speed, and the tire slips because the road surface is slippery, and the rotation speeds of the motor 1 and the motor 2 repeatedly vibrate. That is, when a driving force is applied in an attempt to follow the target rotation speed, the vehicle slips and the rotation speed increases, and the control of reducing the rotation speed is repeated in order to suppress the increase. FIG. 8 (c) shows the time variation of the slip ratio, which is not controlled within the maximum slip ratio (0.2).

FIG. 9 is a control method of the present embodiment, and is a result of traveling on a low μ road in combination with a target vehicle speed tracking control (S106) and a slip suppression control (S107). FIG. 9 (a) shows the time change of the vehicle speed, and as in FIG. 8 (a), the force generated by the tire is small because the μ is low and the road surface is slippery (the force generated by the tire is μ · Fz (Fz =). m · g, where m is the load applied to the tire)), indicating that the driving force becomes smaller and the follow-up to the target vehicle speed becomes slightly slower. FIG. 9 (b) shows the time change of the rotation speed, and when the tire exceeds the slip limit (maximum slip ratio), the slip suppression control is executed, so that the vibration as shown in FIG. 8 (b) does not occur and the tire rotates smoothly. Indicates that the number will increase. FIG. 9C shows a time change of the slip ratio, which is controlled within the maximum slip ratio (0.2).

As described above, in the present embodiment, the slip determination means 20 determines whether or not the slip ratio exceeds the maximum slip ratio, and if it is within the maximum slip ratio, the target vehicle speed tracking control is executed and the maximum slip ratio is exceeded. If so, by executing the slip suppression control, it is possible to control so as not to shift to the slip state, and even if the slip state is reached, the slip state can be suppressed.

Further, as can be seen from the equation (3), not only the current motor rotation speed and the current vehicle speed are used to determine whether or not the vehicle is in the stable region, but also the target motor rotation speed and the target vehicle speed are used to determine whether or not the vehicle is in the stable region. Since it is possible to determine whether or not, it is possible to always determine the upper limit of the motor rotation speed in the stable region with respect to the current vehicle speed, and it is possible to control so as not to enter the slip state.

Further, in the slip suppression control, the redundancy of a plurality of motors 1 and 2 is used to coordinately control each motor so as to minimize the given evaluation function, so that the minimum operation amount or the minimum operation is performed. The slip state can be suppressed in time.

10 Operation amount detection means, 12 Target derivation means, 14 Vehicle state detection means, 16 Motor state detection means, 18 Optimal control means, 20 Slip determination means, 22 Slip suppression control means, 24 Control amount determination means, 26 Motor control means.

Claims (4)

Operation amount detection means for detecting the operation amount of the vehicle, and
Vehicle condition detection means that detects at least the vehicle speed of the vehicle,
A motor state detecting means that detects at least the motor rotation speed of the motor that drives the vehicle, and
A target vehicle speed calculation means for calculating a target vehicle speed of a vehicle based on the operation amount and the vehicle speed, and
When the slip ratio of the vehicle calculated based on the vehicle speed and the motor rotation speed is within the maximum slip ratio at which the tire generation force of the vehicle is stable, the target vehicle speed tracking control that follows the target vehicle speed is executed. A control means that executes slip suppression control instead of the target vehicle speed tracking control when the maximum slip ratio is exceeded, and
Equipped with
The motor includes a first motor and a second motor.
The first motor is connected to the sun gear of the planetary gear and is connected to the sun gear.
The second motor is connected to the ring gear of the planetary gear.
The carrier of the planetary gear is connected to the output shaft of the vehicle and is connected to the output shaft of the vehicle.
The control means is characterized in that, as the slip suppression control, the slip ratio is controlled so as to minimize the change in the rotation speed of the first motor and the second motor in order to keep the slip ratio within the maximum slip ratio. Vehicle travel control device. In the vehicle travel control device according to claim 1,
The control means is
N1: Rotational speed of the first motor N2: Rotational speed of the second motor Np: Output shaft rotational speed Nt: Tire rotational speed Gr: Differential gear ratio R: Tire radius V: Vehicle speed ρ: Planetary gear ratio S *: Maximum slip ratio g1, g2: Weight coefficient u1: Change in rotation speed of the first motor u2: Change in rotation speed of the second motor
As an evaluation function
J1 = min {g1 ・ u1 ² + g2 ・ u2 ² }
And as a constraint,
(N1 + u1) + (1 / ρ) ・ (N2 + u2) --f (S *) = 0
However, f (S *) = (1 + ρ) ・ Gr ・ V / (ρ ・ R ・ (1-S *))
Control to meet,
A vehicle travel control device characterized by this. Operation amount detection means for detecting the operation amount of the vehicle, and
Vehicle condition detection means that detects at least the vehicle speed of the vehicle,
A motor state detecting means that detects at least the motor rotation speed of the motor that drives the vehicle, and
A target vehicle speed calculation means for calculating a target vehicle speed of a vehicle based on the operation amount and the vehicle speed, and
When the slip ratio of the vehicle calculated based on the vehicle speed and the motor rotation speed is within the maximum slip ratio at which the tire generation force of the vehicle is stable, the target vehicle speed tracking control that follows the target vehicle speed is executed. A control means that executes slip suppression control instead of the target vehicle speed tracking control when the maximum slip ratio is exceeded, and
Equipped with
The motor includes a first motor and a second motor.
The first motor is connected to the sun gear of the planetary gear and is connected to the sun gear.
The second motor is connected to the ring gear of the planetary gear.
The carrier of the planetary gear is connected to the output shaft of the vehicle and is connected to the output shaft of the vehicle.
As the slip suppression control, the control means controls so that the arrival time for keeping the slip rate within the maximum slip rate is minimized.
A vehicle travel control device characterized by this. In the vehicle traveling control device according to claim 3,
N1: First motor rotation speed N2: Second motor rotation speed Np: Output shaft rotation speed Nt: Tire rotation speed Gr: Differential gear ratio R: Tire radius V: Vehicle speed ρ: Planetary gear ratio S *: Maximum slip ratio u1: Change in the rotation speed of the first motor u2: Change in the rotation speed of the second motor du1: Response speed of the first motor du2: Response speed of the second motor
As an evaluation function
J2 = min {(u1 / du1) ² + (u2 / du2) ² }
And as a constraint,
(N1 + u1) + (1 / ρ) ・ (N2 + u2) --f (S *) = 0
However, f (S *) = (1 + ρ) ・ Gr ・ V / (ρ ・ R ・ (1-S *))
Control to meet,
A vehicle travel control device characterized by this.

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