WO2019054382A1 - Slip control device - Google Patents

Abstract

Provided is a slip control device with which it is possible to exercise stable slip control even when the accuracy of measuring a wheel rotation speed deteriorates during low speed time and prevent vehicle behavior from being disturbed. The present invention is applied to a slip control device 11 for calculating deviation (Δω) between a wheel rotation speed (ω) and a permissible rotation speed (ω') or deviation (Δλ) of a slip ratio (λ), and exercising feedback control by the deviation (Δω) using each of variable gains (PKI, KP, KD) for performing integral compensation and proportional compensation or differential compensation or both. A feedback gain change unit (14, 14A) is included which, when a vehicle speed (V) is less than or equal to a threshold (Vth), reduces one or both of a proportional gain (KP) and a differential gain (KD) and maintains as is or reduces an integral gain (KI) among the gains used for the feedback control.

Description

Slip control device Related application

This application claims the priority of Japanese Patent Application No. 2017-175418 filed on Sep. 13, 2017 and Japanese Patent Application No. 2018-016389 filed on Feb. 1, 2018, which are incorporated by reference in their entirety. Quoted as making money.

The present invention relates to a slip control device that suppresses tire slip of a vehicle, and more particularly to a slip control device of an electric vehicle in which each wheel is driven by an electric motor.

Conventionally, a slip control device is known that prevents the wheels from spinning or locking when the vehicle is accelerating or decelerating. For example, in the method described in Patent Document 1, when the value of the angular acceleration of the drive wheel exceeds the angular acceleration threshold during acceleration, a torque command correction value including a term obtained by multiplying the angular acceleration by the feedback gain is used. Feedback control to the torque command.

JP-A-8-182119 JP 2017-022870 A

In Patent Document 1, when the value of the angular acceleration of the drive wheel exceeds the angular acceleration threshold during acceleration, feedback to torque command is performed using a torque command correction value including a value obtained by multiplying the angular acceleration by a feedback gain. A method of performing slip control by performing control is described. In this slip control, the angular acceleration threshold or the feedback gain is changed in accordance with the wheel rotational speed.

Here, in the method of Patent Document 1, in consideration of the output characteristics of the motor, the feedback gain is changed because a large torque can not be produced in the high rotation range. However, it does not take into consideration fluctuations in measured values of wheel rotational speed at low speeds. The wheel rotational speed is measured from the change in the number of input pulses per unit time. When traveling at low speed, the number of input pulses per unit time itself decreases, so the measurement accuracy deteriorates. If the measurement accuracy of the wheel rotational speed is degraded, vibration is generated by feedback control, so stable feedback control can not be performed.

When feedback control is performed using the slip ratio instead of the wheel rotational speed, similar to the above, stable feedback control can not be performed if the measured value of the wheel rotational speed fluctuates. The slip ratio λ is calculated from the wheel rotation speed ω and the vehicle speed V according to the following equation (Equation (1)), and the wheel rotation speed is included in the equation (1). R ₀ is the radius of the tire.

Although it is conceivable to uniformly reduce the gain in order to suppress the vibration, if the gain is reduced, the responsiveness of the slip control may be reduced, so that it may not be possible to prevent the spin or lock of the wheel.
In addition, if the wheels spin or lock when the vehicle speed V is high, the vehicle behavior may be disturbed and dangerous.

An object of the present invention is to provide a slip control device capable of performing stable slip control even when the measurement accuracy of the wheel rotation speed deteriorates at low speed, and preventing the vehicle behavior from being disturbed.

Hereinafter, in order to facilitate understanding, for convenience, reference will be made to the reference numerals of the embodiments.

The slip control device 11 according to the first configuration of the present invention is mounted on a vehicle 1 capable of being accelerated by power running of the electric motor 4 and decelerated by regeneration, and the wheel rotational speed deviation Δω with respect to the allowable rotational speed ω ′ of the wheel rotational speed ω. The wheel is calculated using at least one of a variable proportional gain K _P performing proportional compensation and a variable differential gain K _D performing differential compensation and a variable integral gain K _I performing integral compensation. A slip control device 11 which acquires a feedback calculation value K _PID from a rotational speed deviation Δω, changes an input braking / driving command value using the feedback calculation value K _PID , and drives the motor 4,
When the vehicle speed V is less than or equal to a predetermined threshold value V _th (V _{th_P} , V _{th_I} , V _{th_D} D), a gain used to obtain the feedback calculation value K _PID among the proportional gain K _P and the differential gain K _D If both are the proportional gain K _P and the derivative gain K _D , both gains K _P , K _D or any one of the gains are decreased, and the gain used to obtain the feedback calculation value K _PID is the proportional gain K If either _P or differential gain K _D is used, the gain to be used is reduced, and the integral gain K _I is maintained or reduced as it is,
The ratio of the size after reduction to the size before reduction of each gain K _P , K _I , K _{D After} the reduction of the integral gain K _I among the ratios α _P , α _I , α _D after reduction The feedback gain change unit 14 that maximizes the ratio α _I is provided.

The post-decrease rates α _P , α _I and α _D also include the rates when maintaining the gains not to be decreased. Further, the "integral gain K _I wherein the greatest proportion alpha _I after reduction in" is one of the other gain K _P, decreases after the ratio of K _D alpha _P, reduction of alpha _D and integral gain K _I As long as the post proportion α _I is the same, it may be sufficient to satisfy the items described in “Relationship to be satisfied” to be described later. The predetermined threshold value V _th and the allowable rotation speed ω ′ are appropriately determined by design and the like.

In this configuration, the feedback gain changing unit 14 reduces the feedback gain when the vehicle speed V is less than or equal to the predetermined threshold value V _th , but the slip control device 11 calculates the feedback calculation value K _PID. The feedback control to be performed may be any of PID control, PI control, and ID control. When the vehicle speed threshold V _th or less, the gain is reduced as described above, but the magnitude relationship of the ratio of the magnitude of the gain after the reduction to that before the reduction is the after-reduction ratio α _I of the integral gain K _I The other may be any relationship as long as it is the largest.

If PID control, may be either lowered only one of the proportional gain K _P and the differential gain K _D. However, since the after-reduction ratio α _{I of the} integral gain K _I must always be the largest, in this case, the value of the integral gain K _I is not necessarily reduced.

That is, the after-reduction rates α _P , α _I and α _D of the respective gains K _P , K _I and K _D include all cases where the following conditions are satisfied.
[Relationship to be satisfied]
In the case of PID control, α _I αα _P and α _I α α _D (however, the relation between α _P and α _D does not matter).
If PI control, α _I α α _P
In the case of ID control, α _I α α _D
However,
α _P = K _P / K _{B_P} , α _I = K _I / K _{B_I} , and α _D = K _D / K _{B_D} .
here,
K _P , K _I , and K _D are the magnitudes of the respective gains after the decrease (during the decrease),
K _{B — P} , K _{B — I} , and K _{B — D} are magnitudes (reference values) of the respective gains before reduction.
In this specification, in the case where each gain is indicated before and after the drop, it is marked as K _P , K _I and K _{D in the} same manner as after the drop (during the drop).

Here, the threshold _{V Th_P} of the vehicle speed V to lower from the reference value of each gain, _{V Th_I,} When _{V Th_d,} inevitably, it is necessary to satisfy the following equation.
V _{th_I} ≦ V _{th_P} , V _{th_D}
At this time, all the three threshold _values may be the same ( _{Vth_P} = _{Vth_I} = _{Vth_D} = _Vth ) regardless of the magnitude relationship between _{Vth_P} and _{Vth_D} .

_Assuming that the post-drop ratio of each gain at 0 km / h is α 0 _{_ P} , α 0 _{_ I} , α 0 _{_ D} , the above α _P = K _P / K _{B _ P} , α _I = K _I / K _{B _ I} , α _D = K _D / If the relational expression K _{B _D} is satisfied, α 0 _{_P} , α 0 _{_I} , and α 0 _{_D} may be set in any way. ₀ <V 0 <V _th is set to V ₀ such that ₍₌ V th_P, either larger or V _{Th_d),} until V ₀ α _{0_P,} α _{0_I,} by keeping one or more alpha _{0_D} It is also good.

The slip control device 11 according to the second configuration of the present invention is mounted on a vehicle 1 capable of being accelerated by power running of the electric motor 4 and decelerated by regeneration and has a slip ratio λ calculated from the wheel rotation speed ω and the vehicle speed V. A variable that performs integral compensation with at least one of a variable proportional gain K _P that performs proportional compensation and a variable differential gain K _D that performs differential compensation while calculating slip ratio deviation Δλ with respect to slip ratio tolerance λ ′ The feedback calculation value K _PID is calculated from the slip ratio deviation Δλ using the integral gain K _I of the above, and the input driving / driving command value is changed using the feedback calculation value K _PID to drive the electric motor 4 The slip control device 11 is
The vehicle speed V is a predetermined threshold value _{V th (V th_P, V th_I} , V th_D) when: among the proportional gain _{K P} and the derivative gain _{K D,} the gain to be used for acquisition of the feedback calculation value _{K PID} is proportional gain K _P and the derivative gain K _D both gain K _P of both the case of _the, K _D, or any decrease one of the gain, the gain used for calculation of the feedback calculation value K _PID proportional gain K _P and derivative gain K if either one of the _D reduces the gain of using them, the integral gain K _I is or decrease as it is maintained,
The ratio of the size after reduction to the size before reduction of each gain K _P , K _I , K _{D After} the reduction of the integral gain K _I among the ratios α _P , α _I , α _D after reduction A feedback gain changing unit 14A that maximizes the ratio α _I is provided.

The post-decrease rates α _P , α _I and α _D also include the rates when maintaining the gains not to be decreased. Further, the conditions and the method for reducing the gain are the same as the slip control device 11 according to the first configuration. For example, as in the slip control device 11 according to the first configuration, the feedback control may be any of PID control, PI control, and ID control. When reducing the gain in the case of PID control, may reduce both the proportional gain K _P and the differential gain K _D, or may be either only to reduce the.
The predetermined threshold value V _th and slip ratio allowable value λ ′ are values appropriately determined by design and the like.

The operation of the slip control device 11 according to the first and second configurations will be described.
During low-speed traveling, when the detection output of the wheel rotational speed ω is a pulse, the number of input pulses per unit time decreases, and the measurement accuracy of the wheel rotational speed ω deteriorates. Therefore, wheel rotational speed deviation Δω (for example, deviation Δω of wheel rotational speed ω with respect to allowable rotational speed ω ′ obtained by multiplying wheel rotational speed ω by a predetermined constant, slip ratio deviation Δλ (slip ratio allowable value λ ′ (upper limit The variation of slip ratio λ with respect to (> 0) or the lower limit (≦ 0) becomes large.

Here, feedback control includes proportional compensation, integral compensation and differential compensation. Differential compensation and proportional compensation tend to be oscillatory due to fluctuations of the wheel rotational speed deviation Δω and the slip ratio deviation Δλ. The differential compensation differentiates the wheel rotational speed deviation Δω and the slip ratio deviation Δλ, and thus amplifies the vibration. The proportional compensation also reflects the fluctuation of the wheel rotational speed deviation Δω and the slip ratio deviation Δλ as it is on the compensation value. On the other hand, integral compensation does not easily become oscillatory even if the wheel rotational speed deviation Δω and the slip ratio deviation Δλ change. Integral compensation integrates the wheel rotational speed deviation Δω and the slip ratio deviation Δλ, and therefore reduces the influence of fluctuations in the wheel rotational speed deviation Δω and the slip ratio deviation Δλ.

Therefore, at low speeds, the gains (proportional gain K _P and derivative gain K _{D, respectively} ) of the proportional compensation and derivative compensation that are likely to generate vibrations are reduced or zeroed to weaken or ineffective the proportional compensation and derivative compensation. Turn As a result, stable slip control can be performed even when the measurement accuracy of the wheel rotation speed ω deteriorates at low speed, and the vehicle behavior can be prevented from being disturbed.

The feedback gain changing unit 14 (14A) determines whether the vehicle is accelerating or decelerating, and the proportional gain K _P , the integral gain K _I , and the differential gain K _D are determined during acceleration and deceleration. The method of reducing the gain to be reduced when the vehicle speed V is less than or equal to the threshold value V _th may be changed for any one or more. That is, the type of compensation for reducing the gain may be changed between acceleration and deceleration, or the degree of reduction may be changed, or the change of the degree of reduction may be changed. Since the influence of each gain K _P , K _I , and K _{D on} stable slip control differs between deceleration and acceleration, it is preferable to change the method of reducing the gain between deceleration and acceleration.

The slip control device 11 according to the first configuration further applies an established rule, and acquires the allowable wheel rotation speed ω ′ from the detection value of the state quantity of the factor of the vehicle affecting the slip. Using the gains K _P , K _I , and K _D of the speed compensation unit 12, the wheel rotation speed deviation calculation unit 13 for calculating the wheel rotation speed deviation Δω, and the proportional compensation, integral compensation, and differential compensation, respectively. A controller 15A that acquires a feedback operation value K _PID from the wheel rotational speed deviation Δω, and a control that changes the input braking / driving command value using the feedback operation value K _PID and outputs it to the controller 10 of the motor 4 The feedback gain changing unit 14 includes a drive command value calculating unit 16, and the feedback gain changing unit 14 performs proportional gain control during acceleration at the same vehicle speed when the vehicle is decelerating. Down K _P or derivative gain K the post-change ratio alpha _P of _{D ', α I', α} D may 'an integral gain K _I the ratio after reduction alpha _I' of a structure to reduce the divided by the.

That is, the post-change ratio of each gain K _P , K _I , K _D at deceleration (the ratio after change to the size before change) is α _P ', α _I ', α _D ', each at acceleration Assuming that the post-change ratio of the gains K _P , K _I and K _D (the ratio after the change to the size before change) is α _P , α _I and α _D , respectively, the gain K _P satisfies the following relationship , K _I , change K _D.
In the case of PID control, α _P / α _I αα _P '/ α _I ' and α _D / α _I αα _D '/ α _I '
In the case of PI control, α _P / α _I α α _P '/ α _I '
In the case of ID control, α _D / α _I α α _D '/ α _I '
At the time of deceleration, by changing the gains K _P , K _I and K _D so that integral compensation becomes dominant, more stable feedback control becomes possible. In this case, when comparing the percentage alpha _I integral gain K _I at acceleration and deceleration is better to reduce the person at the time of acceleration is more effective. In addition, when the proportions α _P 'and α _D ' of the gains K _P and K _D for proportional compensation and differential compensation are compared between acceleration and deceleration, it is more effective to reduce the deceleration. .

As the established rules, for example, a map or the like is determined in advance the relationship between the detection value of the vehicle speed V and the steering wheel angle [delta] _h and the allowable rotation speed omega 'by the allowable rotation speed acquisition section 12, the defined relationship May be used to obtain the allowable rotation speed ω ′. Furthermore, the allowable rotation speed ω ′ may be acquired in consideration of the yaw rate γ. Alternatively, the allowable rotation speed acquisition unit 12 may set a value obtained by multiplying the detected value of the wheel rotation speed ω by a predetermined constant as the allowable rotation speed ω ′.

The slip control device 11 according to the second configuration further includes a slip ratio calculation unit 21 that calculates a slip ratio λ from the wheel rotational speed ω and the vehicle speed V5, and a slip ratio deviation that calculates the slip ratio deviation Δλ. A controller 15A for acquiring a feedback calculation value K _PID from the slip ratio deviation Δλ using the calculation unit 22, the gains K _P , K _I , and K _D of the proportional compensation, the integral compensation, and the differential compensation, and And a braking / driving command value calculating unit 16A for changing the inputted braking / driving command value using the feedback calculation value K _PID and outputting the same to the controller of the motor 4. The feedback gain changing unit 14A when you are in, than during acceleration at the same vehicle speed, the proportional gain K _P or the change after the proportion of the derivative gain _{K D α P ', α I} ' alpha _D may 'an integral gain K _I the ratio after reduction alpha _I' of a structure to reduce the divided by the.
As in the first configuration, the gains K _P , K _I , and K _D are changed so as to satisfy the following relationship.
In the case of PID control, α _P / α _I αα _P '/ α _I ' and α _D / α _I αα _D '/ α _I '
In the case of PI control, α _P / α _I α α _P '/ α _I '
In the case of ID control, α _D / α _I α α _D '/ α _I '
As described above, by changing the gains K _P , K _I and K _D so that integral compensation becomes dominant during deceleration, more stable feedback control is possible.

The feedback gain changing unit 14, when the vehicle speed V is less than the threshold value V _th, either or both of the proportional gain K _P and the derivative gain K _D, a configuration for changing a value equal to or close to zero It is also good. Thus, by changing one or both of the proportional gain K _P and the differential gain K _D to zero or a value close to zero, the after-reduction ratio α _P (α 0 _{_P} ) or α _D (α 0 _{_D} ) or Both of them may be zero or close to zero. The “value close to zero” is a value that can be regarded as zero in control, and is determined by design.

A plurality of drive wheels 2 may be independently controlled in the vehicle 1, and the electric motor 4 may be configured to drive the corresponding drive wheels 2 of the plurality of drive wheels 2. The electric motor 4 in the vehicle 1 capable of independently controlling the drive wheels 2 may be an in-wheel motor type or an on-board type. In the case of the vehicle 1 in which the drive wheels 2 can be controlled independently, the slip control of each drive wheel 2 can be performed independently, so that the slip control effect can be obtained more effectively.

Any combination of the at least two configurations disclosed in the claims and / or the description and / or the drawings is included in the present invention. In particular, any combination of two or more of the claims is included in the present invention.

The invention will be more clearly understood from the following description of the preferred embodiments with reference to the accompanying drawings. However, the embodiments and the drawings are for the purpose of illustration and description only and are not to be taken as limiting the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in multiple drawings indicate the same or corresponding parts.
BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the conceptual structure of an example of the vehicle carrying the slip control apparatus which concerns on the 1st and 2nd embodiment of this invention. It is a functional block diagram which shows the conceptual structure of the slip control apparatus of FIG. It is a functional block diagram showing a conceptual composition of a slip control device concerning a 2nd embodiment. It is a graph which shows the example of a change of the feedback gain by the slip control apparatus of FIG. 1 or FIG. It is a graph which shows the other example of a change of the feedback gain by the slip control apparatus of FIG. 1 or FIG. It is a graph which shows the other example of a change of the feedback gain by the slip control apparatus of FIG. 1 or FIG. It is a graph which shows the other example of a change of the feedback gain by the slip control apparatus of FIG. 1 or FIG. It is a graph which shows the time change example of compensation value, a vehicle speed, and a wheel speed. It is a graph which shows the other example of a change of the feedback gain by the slip control apparatus of FIG. 1 or FIG. It is a graph which shows the other example of a change of the feedback gain by the slip control apparatus of FIG. 1 or FIG. It is a graph which shows the other example of a change of the feedback gain by the slip control apparatus of FIG. 1 or FIG. It is a graph which shows the compensation value, a vehicle speed, and the other example of time change of a wheel speed. It is a sectional view showing an example of an in-wheel motor drive.

<< Whole vehicle configuration >>
A first embodiment of the present invention will be described in conjunction with FIG. 1, FIG. 2 and FIG. As shown in FIG. 1, the slip control device according to this embodiment is provided in a vehicle 1 provided with a rotary electric motor 4 that constitutes an in-wheel motor drive device 3 for each of the four drive wheels 2. . The vehicle 1 is capable of accelerating by powering and decelerating by regeneration of the electric motor 4, and can control four wheels independently.

For example, as shown in FIG. 13, each in-wheel motor drive device 3 decelerates the rotation output of the wheel bearing 5, the electric motor 4, and the electric motor 4 to the hub wheel 5 a that is the rotating wheel of the wheel bearing 5. And a speed reducer 6 for transmission. The wheel of the drive wheel 1 (FIG. 1) is attached to the hub wheel 5a. The motor 4 is, for example, an AC motor such as a synchronous motor, and includes a stator 4a and a rotor 4b. The in-wheel motor drive device 3 is provided with a wheel rotational speed sensor 7 (FIG. 1). The wheel rotation speed sensor 7 includes, for example, a magnetic encoder and a magnetic sensor, and outputs a pulse train of pulse intervals proportional to the wheel rotation speed ω. Further, instead of the wheel rotational speed sensor 7, the value of the resolver 23 of FIG. 13 may be used. The resolver 23 is a sensor that detects the rotational speed of the rotor of the motor 4 and outputs a value proportional to the wheel rotational speed.

In FIG. 1, the amount of depression of an accelerator pedal and a brake pedal is input from various sensors 9 to a host ECU 8 such as a VCU that comprehensively controls the vehicle 1, and the host ECU 8 controls the motor 4 of each drive wheel 1. Distribute the braking and driving command to ten. The motor controller 10 controls an inverter that converts DC power of a battery (not shown) into AC power according to the motor 3, and controls the output of the inverter according to the input control command and outputs the rotational phase of the motor 3 and the like. It is comprised with the control means which performs control of efficiency etc. according to it. The motor controller 10 is provided for each of the individual electric motors 4, but two each of the front wheel side and the rear wheel side are combined in one case, and in FIG. Shown as a block of one motor controller 10.

The various sensors 9 represent an accelerator pedal sensor, a brake pedal sensor, and other various sensors as one representative. The slip control device 11 intervenes between the host ECU 8 and the motor controller 10.

The slip control device 11 is provided for each of the motors 4 but is represented by one block in FIG. The vehicle speed V is input to the slip control device 11 from the vehicle speed detection means 17, and each wheel rotational speed ω detected by the wheel rotational speed sensor 7 of each motor 4 is input via the motor controller 10.

<< First Embodiment, Slip Control Device >>
FIG. 2 shows an example of a conceptual configuration of the slip control device 11. The slip control device 11 includes an allowable rotation speed acquisition unit 12, a wheel rotation speed deviation calculation unit 13, a feedback gain change unit 14, a controller 15, and a braking / driving command value calculation unit 16. The allowable rotation speed acquisition unit 12 is a unit that acquires the allowable wheel rotation speed ω ′ from the detection value of the state quantity of the factor of the vehicle that affects the slip by applying a defined rule. As the determined rule, for example, the relationship between the detected values of the vehicle speed V, the steering wheel angle δ _h and the yaw rate γ and the allowable rotation speed ω ′ is determined by a map (not shown) etc. The unit 12 is to obtain the allowable rotation speed ω ′ using this relationship. The yaw rate γ may not necessarily be included in the above relationship. Alternatively, the allowable rotation speed acquisition unit 12 may obtain the allowable wheel rotation speed ω ′ by multiplying the wheel rotation speed ω by a predetermined constant. The map is stored in storage means such as a memory of the slip control device 11.

The vehicle speed V is detected by the vehicle speed detection means 17. The steering wheel angle [delta] _h is the steering angle from the neutral position of the steering wheel (not shown), is measured by the steering wheel angle measuring means 18. The yaw rate γ is measured by the yaw rate measurement means 19 installed in the vehicle 1. The wheel rotational speed ω is detected by the wheel rotational speed sensor 7 (see FIG. 1) and transferred from the motor controller 10.

The wheel rotational speed deviation calculation unit 13 is a means for calculating the deviation of the wheel rotational speed ω with respect to the allowable rotational speed ω ′, that is, the wheel rotational speed deviation Δω (the deviation of the actual wheel rotational speed ω from the allowable rotational speed). . The controller 15 is, for example, a PID controller, and uses feedback gains for the wheel rotational speed deviation Δω using variable gains K _P , K _I and K _D for performing proportional compensation, integral compensation, and differential compensation, respectively. It is a means to calculate K _PID . The feedback calculation value _KPID is a value in the same unit as the braking / driving instruction given from the host ECU 8 to the slip control device 11, and is a torque value in this example.

The braking / driving command value calculation unit 16 is means for changing the braking / driving command value input from the host ECU 8 using the feedback calculation value _KPID and outputting it to the motor controller 10. In this example, the braking / driving command value commanded by the host ECU 8 is a torque command value, and the feedback operation value K _PID is also a torque value. Therefore, in this example, the braking / driving command value calculation unit 16 is a torque command value calculation unit.

The feedback gain changing unit 14 is means for changing the gains K _P , K _I , and K _D of the proportional compensation, integral compensation, and differential compensation used by the controller 15, and the vehicle speed V is a threshold value V _th. when: the proportional gain K _P and the derivative gain K out and _D, the gain used for calculation of the feedback calculation value K _PID proportional gain K _P and the differential gain K gain both in which case both _D K _P , K _D or one of the gains is decreased, and when the gain used for calculation of the feedback calculation value K _PID is any one of the proportional gain K _P and the differential gain K _D , the used gain is decreased, integral gain K _I is or decreased to maintain it, the relative magnitude of the pre-reduction of the gain K _P, K _I, K _D The proportion of the size is reduced after the ratio alpha _P after _below, α _I, α _{D (but} also the ratio after reduction ratio when the gain does not decrease was maintained alpha _P, alpha _I, referred to as alpha _D) for, The post-reduction ratio α _I of the integral gain K _I is maximized.

Here, “to make the ratio α _I after the decrease of the integral gain K _I the largest” means to satisfy the following relationship.
[Relationship to be satisfied]
In the case of PID control, α _I αα _P and α _I α α _D (however, the relation between α _P and α _D does not matter).
If PI control, α _I α α _P
In the case of ID control, α _I α α _D
However,
α _P = K _P / K _{B_P} , α _I = K _I / K _{B_I} , and α _D = K _D / K _{B_D} .
here,
K _P , K _I , and K _D are the magnitudes of the respective gains after the decrease (during the decrease),
K _{B — P} , K _{B — I} , and K _{B — D} are magnitudes (reference values) of the respective gains before reduction.
Note that α _I may be larger than α _P and α _D as follows. That is, the same value may be excluded.
For PID control, α _I > α _P and α _I > α _D (however, the relationship between α _P and α _D does not matter).
If PI control, α _I > α _P
In the case of ID control, α _I > α _D

More specifically, the feedback gain changing unit 14 performs the proportional compensation and integration when the vehicle speed V is _{equal to} or less than the threshold values V _{th_P} , V _{th_I} , and V _{th_D} determined for each gain as the threshold value V _th. The ratio of the size after reduction to the size before reduction of the gain K _I of the integral compensation by reducing the gains K _P , K _I and K _D of the compensation and the differential compensation, the gain of the proportional compensation and the derivative compensation The ratio of the size after reduction to the size before reduction of K _P and K _D is made larger. _Assuming that the size of each gain before reduction is K _{B — P} , K _{B — I} and K _{B — D,} and the ratio after reduction which is the ratio of the size after reduction is α, α of each gain is expressed by the following equations (2) to (2) It becomes 4).
α _P = K _P / K _{B_P} (2)
α _I = K _I / K _{B_I} (3)
α _D = K _D / K _{B_D} (4)
The feedback gain changing unit 14 makes the after-reduction rates α _P and α _D of the proportional gain K _P and the differential gain K _D smaller than the after-reduction rate α _I of the integral gain K _I. For example, the feedback gain changing unit 14 changes the gains K _P and K _D of the proportional compensation and the differential compensation to zero. The gains K _P and K _D of the proportional compensation and the differential compensation may not necessarily be reduced to zero, but may be values close to zero. Proportions after reduction α _P and α _D of proportional gain K _P and differential gain K _D may be different values or may be the same value as each other.

As an example, the feedback gain changing unit 14
The proportional gain K _P is changed from 1000 to 0, and at this time, the ratio α _P of the size after change is 0%,
The integral gain K _I is changed from 10 to 2, and at this time, the ratio α _I of the size after the change is 20%,
The derivative gain K _D is changed from 0 to 100, this time, the ratio alpha _D size after the change is 0%. In this example was zero both alpha _P and alpha _D, alpha _P and alpha value of _D is may be smaller than α _I, α _P and alpha _D so that different values K _P, a K _D You may change it.

Note that the threshold values V th — _P , V _{th — I} and V _{th — D of} the velocity determined for each gain may be different values or may be the same value. However, the magnitude relationship is necessarily as follows (see FIGS. 4 and 5).
In the case of PID control, V _{th_I} V V th _{_ P} and V th _{_ I} V V th _{_ D} (however, the magnitude relationship between V th _{_ P} and V th _{_ D} does not matter)
In the case of PI control, V _{th_I} V V _{th_P}
In the case of ID control, V _{th_I} V V _{th_D}

The feedback gain changing unit 14 changes the gain of the integral compensation (integral gain K _I ) by determining whether the vehicle is accelerating or decelerating. Specifically, when accelerating, the gain K _{I of the} integral compensation is made smaller than the reference value. When decelerating, the integral gain is made larger than that during acceleration at the same vehicle speed V. The "reference value" is a value appropriately and independently determined by design. The feedback gain changing unit 14 includes an acceleration / deceleration determination unit 14a that determines whether the vehicle 1 is accelerating or decelerating. The acceleration / deceleration determination unit 14a determines whether the vehicle is accelerating or decelerating based on, for example, the positive / negative acceleration signal of an acceleration sensor (not shown).

<Action and effect>
During low-speed traveling, the number of pulses per unit time of the wheel rotational speed sensor 7 input to the slip control device 11 as the wheel rotational speed ω decreases, and the measurement accuracy of the wheel rotational speed ω deteriorates. Therefore, the fluctuation of the wheel rotational speed deviation Δω becomes large. Here, differential compensation in feedback control and proportional compensation are likely to become oscillatory due to fluctuations in the wheel rotational speed deviation Δω. Differential compensation amplifies the vibration to differentiate the wheel rotational speed deviation Δω. The proportional compensation also reflects the fluctuation of the wheel rotational speed deviation Δω as it is to the compensation value. On the other hand, integral compensation is less likely to become oscillatory even if the wheel rotational speed deviation Δω changes. The integral compensation integrates the wheel rotational speed deviation Δω, thereby reducing the influence of the fluctuation of the wheel rotational speed deviation Δω. Therefore, at the time of low speed traveling, the proportional compensation gain K _P and the differential compensation gain K _D which easily cause vibration are reduced or made zero to invalidate the proportional compensation and the differential compensation. As a result, stable slip control can be performed even when the measurement accuracy of the wheel rotation speed ω deteriorates at low speed, and the vehicle behavior can be prevented from being disturbed.

The influence of the gain K _I of the integral compensation differs depending on whether the vehicle 1 is accelerating or decelerating. Therefore, the feedback gain changing unit 14 determines whether the vehicle 1 is accelerating or decelerating, and makes the integral compensation gain K _I smaller than the reference value when accelerating. During acceleration, slip control can be performed while suppressing vibration by making the integral compensation gain K _I smaller than the reference value. As a result, the responsiveness of the slip control is reduced, but this is not a problem because the behavior of the vehicle is less likely to be disturbed even if the responsiveness is reduced at low speed traveling.

When the vehicle is decelerating, the feedback gain changing unit 14 makes the integral gain K _I larger than when accelerating at the same vehicle speed V. At the time of deceleration, the integral value of the wheel rotational speed deviation Δω is large until the vehicle is decelerated to low speed. Therefore, even if the measured value of the wheel rotation speed ω fluctuates at low speed traveling, the influence on the value of the integral compensation becomes small. Therefore, even if the integral gain K _I is made larger than at the time of acceleration, vibrations are less likely to occur. By making the integral gain K _I larger than that during acceleration, feedback control can be performed with better responsiveness. If feedback control can be performed with high responsiveness, it is possible to prevent locking of the wheels and to prevent disturbance of the vehicle behavior. In addition, in the method of changing the gain at the time of acceleration and at the time of deceleration, any one gain may be changed, or there may be a gain not to be changed (see FIG. 11).

As described above, each gain K _P , K _I , K _D in feedback control is changed according to the vehicle speed V, and it is further determined whether the vehicle 1 is accelerating or decelerating. By making the method of reducing the gain K _I different, stable slip control can be performed even if the measurement accuracy of the wheel rotation speed ω deteriorates at low speed, and the vehicle behavior can be prevented from being disturbed.

Moreover, this embodiment is applied to the vehicle 1 which can control each drive wheel 2 of four wheels independently, and since slip control of each drive wheel 2 can be performed independently, a slip control effect is acquired more effectively. Be The details of the operation are the same as those after the decrease and will be described in the second embodiment.

<< Slip Control Device According to Second Embodiment >>
A second embodiment of the present invention will be described in conjunction with FIGS. 3 to 7. This embodiment is the same as the first embodiment, except for items specifically described.

This embodiment differs from the first embodiment in the slip control device 11 in the vehicle 1 described above with FIG. As shown in FIG. 3, the slip control device 11 according to this embodiment includes a slip ratio calculating unit 21, a slip ratio deviation calculating unit 22, a feedback gain changing unit 14A, a controller 15A, and a braking / driving command value calculating unit. And 16A.

Slip rate calculating section 21, a slip ratio lambda, the wheel rotation speed omega, the vehicle speed V, the using yaw rate γ and the steering wheel angle [delta] _h is calculated by the following equation (5) to (10).

Here, R ₀ is a tire radius, β is a side slip angle at the vehicle center of gravity, d _f is a front wheel tread, d _r is a rear wheel tread, and l _f is a distance from the center of gravity position to the front wheel position. The subscripts of V, δ and ω indicate which wheel the vehicle speed V, the steering wheel angle δ _h or the wheel rotational speed ω is. Specifically, FL is the left front wheel, and FR is the right. The front wheel, RL is a left rear wheel, and RR is a right rear wheel. The slip ratio λ represents the degree of slip of the drive wheel 2, and λ = 0 in the grip state, λ> 0 in the locked state, and λ <0 in the wheel spin.

The vehicle speed V is detected by the vehicle speed detection means 17. The steering wheel angle [delta] _h is the steering angle from the neutral position of the steering wheel (not shown), is measured by the steering wheel angle measuring means 18. The yaw rate γ is measured by the yaw rate measuring means 19. The wheel rotational speed ω is detected by the wheel rotational speed sensor 7 (see FIG. 1) and transferred from the motor controller 10.

Slip ratio deviation calculation unit 22 is a deviation of slip ratio λ from slip ratio allowable value λ ′ (upper limit (> 0) or lower limit (<0)), that is, slip ratio deviation Δλ (actual slip ratio λ slip ratio Calculate the deviation from the tolerance value). The slip ratio allowable value λ 'is appropriately determined by design based on simulation and the like.

The controller 15A monitors the slip ratio λ of each drive wheel 2, and when the slip ratio λ exceeds the slip ratio allowable value λ ′ (upper limit (> 0) or lower limit (<0)), the slip ratio A PID operation is performed on the deviation Δλ to obtain a feedback operation value K _PID .

Here, K _P , K _I and K _D are proportional gain, integral gain and differential gain, respectively. In this embodiment, feedback control for performing all of proportional compensation, integral compensation, and differential compensation is shown as an example, but it is also applicable to feedback control for performing proportional compensation and integral compensation or feedback control for performing integral compensation and differential compensation. Good.

The acceleration / deceleration determination unit 14a determines whether the vehicle 1 is accelerating or decelerating. The acceleration / deceleration determining unit 14a determines, for example, whether the vehicle is accelerating or decelerating based on whether the longitudinal acceleration signal of the acceleration sensor (not shown) is positive or negative. The acceleration / deceleration determination unit 14a is provided as a part of the feedback gain change unit 14A.

The feedback gain changing unit 14A obtains the proportional gain K _P , the integral gain K _I , and the differential gain K _D described above according to the vehicle speed V.

The feedback gain changing unit 14A is a means for changing the gains K _P , K _I and K _D of the proportional compensation, integral compensation and differential compensation used by the controller 15A, and the vehicle speed V is determined for each gain. When the threshold values V th _{_ P} , V th _{_ I} and V th _{_ D} are below, the gains K _P , K _I and K _D of the proportional compensation, the integral compensation and the differential compensation are reduced, respectively, and the gain K _I of the integral compensation is reduced. The ratio of the size after reduction to the size before reduction is made larger than the ratio of the size after reduction to the size before reduction of gains K _P and K _D of proportional compensation and differential compensation, respectively. _Assuming that the size of each gain before reduction is K _{B — P} , K _{B — I} , and K _{B — D,} and the ratio of the size after reduction is α, α of each gain is expressed by Equations (12) to (14).
α _P = K _P / K _{B_P} (12)
α _I = K _I / K _{B_I} (13)
α _D = K _D / K _{B_D} (14)
Feedback gain changing unit 14A is the value of alpha _P and alpha _D smaller than alpha _I. For example, the feedback gain changing unit 14A changes the gains K _P and K _D of each of the proportional compensation and the differential compensation to zero. The gains K _P and K _D of the proportional compensation and the differential compensation may not necessarily be reduced to zero, but may be values close to zero.

As an example, the feedback gain changing unit 14A
The proportional gain K _P is changed from 1000 to 0, and at this time, the ratio α _P of the size after change is 0%,
The integral gain K _I is changed from 10 to 2, and at this time, the ratio α _I of the size after the change is 20%,
The derivative gain K _D is changed from 0 to 100, this time, the ratio alpha _D size after the change is 0%. In this example was zero both alpha _P and alpha _D, alpha _P and alpha value of _D is may be smaller than α _I, α _P and alpha _D so that different values K _P, a K _D You may change it.

The feedback gain changing unit 14 changes the gain of the integral compensation (integral gain K _I ) by determining whether the vehicle 1 is accelerating or decelerating. Specifically, when accelerating, the gain K _{I of the} integral compensation is made smaller than the reference value. When decelerating, the integral gain is made larger than that during acceleration at the same vehicle speed V. Further, at the time of deceleration, the value of the integral gain does not necessarily have to be reduced, and may be kept at the reference value. The “reference value” is a value appropriately determined by design.

Braking drive command value calculation unit 16A, by adding the feedback calculation value K _PID to the controller 15A has been calculated braking driving command value higher ECU8 is commanded to acquire a braking drive command value to be output. In this example, the braking / driving command value commanded by the host ECU 8 is a torque command value, and the feedback operation value K _PID is also a torque value. Therefore, in this example, the braking / driving command value calculation unit 16A is a torque command value calculation unit. If the torque command value is negative, that is, if the regenerative brake is applied, the adjusted torque command value that loosens the regenerative brake, and if the torque command value is positive, the adjusted torque command value that loosens the driving torque Calculate As a result, the torque command value of the drive wheel 2 is controlled so that the slip rate λ becomes equal to or less than the slip rate allowable value λ ′, and locking or spin of the drive wheel 2 can be suppressed.

<Action and effect>
As described above, the controller 15A includes proportional compensation and integral compensation and / or differential compensation. Here, at the time of low speed traveling, the measurement accuracy of the wheel rotation speed ω is deteriorated, so that the fluctuation of the slip ratio λ becomes large. Due to the fluctuation of the slip ratio λ, the slip ratio deviation Δλ also changes. When slip ratio deviation Δλ in which fluctuation occurs is input to the controller 15A, differential compensation is the most likely to be the cause of vibration, and next proportional compensation is the cause of the vibration. On the other hand, integral compensation is less likely to cause vibration. The differential compensation amplifies the vibration because it differentiates the slip ratio deviation. Proportional compensation reflects the fluctuation of slip ratio deviation Δλ as it is on the compensation value. On the other hand, integral compensation integrates the slip ratio deviation, thereby reducing the influence of fluctuations in the measured value.

For the above reasons, proportional compensation or differential compensation, which is a cause of vibration, or both of them are weakened or canceled at low speeds. For example, the proportional gain K _P and the differential gain K _D are respectively set to α 0 _{_P} and α _{0 _D} at a vehicle speed of 0 km / h. At this time, by _setting α 0 — _P or α 0 — _D to zero, proportional compensation or differential compensation can be invalidated. These two gains K _P and K _{D change} their values continuously (linearly with respect to the vehicle speed in the illustrated example) at vehicle speeds of 0 to V _th — _P and V _th — _D km / h as shown in FIG. V th — _P and V th — _D are threshold values of gain with respect to the vehicle speed, and are set to 10 to 15 km / h, for example, V _th — _P = 12 km / h and V _th — _D = 15 km / h. In this example, V _{th_P} ≠ V _{th_D} is used, but V _{th_P} and V _{th_D} may have the same value. In FIG. 4, the integral compensation also changes the value continuously at vehicle speeds of 0 to V _{th_I} km / h. In this case, always alpha _I ≧ alpha _P, and changing the value such that α _I ≧ α _D. V _{Th_I,} since it is necessary to set so that _{V th_I} ≦ _{V th_P} and _{V th_I} ≦ _{V th_D,,} for example, 10 km / h. In this _{example, V th_I} the _{V Th_P,} was a value different from the _{V Th_d,} may be set so that _{V th_I} = _{V th_P} or _{V th_I} = _{V th_D,.} For example, the threshold value of the vehicle speed may be increased only for differential compensation, such as V _th — I = V _th — _P ≦ V th — _D.

At this time, as shown in FIG. 5, the magnitude relationship between α _{0 _P} and α 0 _{_D} may be switched depending on the vehicle speed. Integral gain K _I is always in the same manner as FIG. 4 α _I ≧ α _P, and changing the value such that α _I ≧ α _D. In the embodiments of FIGS. 4 and 5, each gain is linearly changed, but the present invention is not limited to this. α _I ≧ α _P, and may be changed non-linearly if the relationship α _I ≧ α _D is satisfied. Further, as shown in FIG. _{6, 0 <V 0} <Set _{V th, V 0 ~ V th} km / h continuously changed value at, ₀ ~ _V 0 km / h to the _{V 0} miles / The value of α set by h may be maintained. α 0 — _P and α 0 — _D may maintain α = 0 as shown in FIG. α is not limited to zero but may be a value close to zero. Further, based on the judgment of the acceleration / deceleration judgment unit, it is assumed that changes in gain are different between acceleration and deceleration.

During acceleration, the gain of integral compensation (integral gain K _I ) is, for example, one-fourth of the reference value (for example, gain of 15 km / h or more) at vehicle speed V ₀ km / h as shown in FIG. As it is done, the gain K _I is changed continuously (linear to the vehicle speed in the illustrated example).

At this time, unlike the proportional gain K _P and the derivative gain K _D , the integral gain K _I is not set to 0 at the vehicle speed V ₀ km / h. This is because slip control does not operate if the integral gain is also set to zero.

FIG. 8 shows vehicle speed V during acceleration, wheel speed, slip control and slip ratio deviation (that is, proportional compensation value), integral compensation value, and differential compensation value in time series. As described above, by setting the gain at the time of acceleration while traveling at low speed, it is possible to perform slip control while suppressing vibration. In addition, although the responsiveness of the slip control is reduced, for example, when the vehicle is traveling at a low speed such as 15 km / h or less, even if the responsiveness of the slip control is reduced, the vehicle behavior is not easily disturbed.

At the time of deceleration, one or more gains are changed to satisfy the following equation (14).
α _P / α _I αα _P '/ α _I ' and α _D / α _I α α _D '/ α _I ' (14)
Here, it is assumed that the post-drop ratio of each gain (the ratio after the drop to the size before the drop) at the time of deceleration is α _P ′, α _P ′, and α _D ′, respectively. That is, when the ratio of the integral compensation gain is compared between the acceleration and the deceleration, the ratio of the gain is larger at the deceleration than at the acceleration. For example, as shown in FIG. 9, a vehicle speed threshold V _{th_I} ′ which is smaller than the vehicle speed threshold V _{th_I} during acceleration is set, and the value is changed in the range of 0 to V _{th_I} km / h. When the after-reduction rates α _I and α _I ′ of the integral compensation gain are compared between acceleration and deceleration, it is more effective to reduce the acceleration as shown in FIG. On the other hand, when the ratio of the gains of proportional compensation or differential compensation is compared, the ratio of gain is made smaller at the time of deceleration than at the time of acceleration. As shown in FIG. 10, for example, the threshold _V 0 which vehicle speed when _{accelerating, V th} different deceleration threshold _{V 0} which vehicle speed _{', V th' the, V 0 <V 0 '<} V th <V _It may be set to be _th ′ and the value may be changed continuously between V ₀ ′ and V _th ′ km / h.

As shown in the figure, when proportional ratios after acceleration / deceleration are compared for the proportional compensation and differential compensation gains after the reductions α _P , α _P ', α _D , α _D ' and α _I '. It is more effective to make it smaller. Here, although the proportional gain and the derivative gain are simultaneously changed in the example of FIG. 10, they may be changed separately. Further, as shown in FIG. 11, it is not necessary to change the method of changing the gain only at the time of acceleration and at the time of deceleration, for example. As described above, by changing the method of changing the gain at the time of acceleration and at the time of deceleration, more stable feedback control becomes possible.

FIG. 11 shows vehicle speed V during deceleration, wheel speed, slip control and slip ratio deviation (that is, proportional compensation value), integral compensation value, and differential compensation value in time series. As described above, slip control can be performed while suppressing vibration by setting the gain at the time of low speed traveling and deceleration. Furthermore, since the integral gain can be set larger than at the time of acceleration, the responsiveness of slip control can be secured, and the vehicle behavior is less likely to be disturbed.

As described above, according to the slip control device 11 of this embodiment, each gain K _P , K _I , K _D in feedback control is changed according to the vehicle speed V, and is the vehicle accelerated or decelerated? By making the change in gain K _I different between acceleration and deceleration, stable slip control can be performed even if the measurement accuracy of wheel rotational speed ω deteriorates at low speed, and vehicle behavior is It can prevent disorder.

Each item described in the second embodiment is the deviation between the slip ratio λ and the slip ratio allowable value λ ′ calculated using the wheel rotational speed ω and the vehicle speed V in the second embodiment. While Δλ is used, the first embodiment can be applied to the first embodiment as it is, except that the deviation Δω between the wheel rotation speed ω and the allowable rotation speed ω ′ is used. . The matters described in the first embodiment can be applied to the second embodiment as it is, except for the difference in the deviation.

Although each of the above embodiments has been described in the case where the invention is applied to a vehicle 1 using the in-wheel motor drive device 3 for four wheels, the present invention relates to an on-board four-wheel independent drive vehicle and left and right wheel independent drive The present invention can be applied to vehicles such as two-wheel drive vehicles of one type and one motor type.

It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all the modifications within the meaning and scope equivalent to the claims.

Reference Signs List 4 motor 7 wheel rotational speed sensor 11 slip control device 14 14A feedback gain changing unit 17 vehicle speed detection means V vehicle speed λ slip ratio λ ′ slip ratio allowable value Δλ slip ratio deviation ω wheel rotation Speed ω '... Permissible rotation speed Δω ... Wheel rotational speed deviation K _PID ... Feedback calculation value

Claims (8)

1. It is mounted on a vehicle that can be accelerated by motor powering and decelerated by regeneration, and it calculates the wheel rotational speed deviation of the wheel rotational speed from the allowable wheel rotational speed, and also performs variable compensation with proportional compensation and variable compensation with proportional compensation. A feedback operation value is obtained from the wheel rotational speed deviation using at least one of the differential gains and a variable integration gain that performs integration compensation, and the input braking / driving command value is used using the feedback operation value. It is a slip control device which changes and drives said electric motor,
   When the vehicle speed is less than a predetermined threshold value and the gain used to obtain the feedback calculation value is both a proportional gain and a differential gain, either one of the proportional gain and the derivative gain, or both of these gains. The gain is decreased, and if the gain used to acquire the feedback operation value is either a proportional gain or a differential gain, the gain used is decreased and the integral gain is maintained or reduced as it is,
   A slip control device, comprising: a feedback gain changing unit that maximizes the after-reduction ratio of the integral gain among the after-reduction ratio that is the ratio of the after-reduction size to the before-reduction size of each gain.
2. A variable proportional unit that is mounted on a vehicle that can be accelerated by power running of an electric motor and decelerated by regeneration, calculates slip ratio deviation with respect to slip ratio allowable value of slip ratio calculated from wheel rotation speed and vehicle speed, and performs proportional compensation. The feedback calculation value is obtained from the slip ratio deviation using at least one of the gain and the variable differential gain that performs differential compensation and the variable integral gain that performs integral compensation, and the input control drive command value is A slip control device for driving the electric motor by changing using the feedback calculation value,
   When the vehicle speed is less than a predetermined threshold value and the gain used to obtain the feedback calculation value is both a proportional gain and a differential gain, either one of the proportional gain and the derivative gain, or both of these gains. The gain is decreased, and if the gain used to acquire the feedback operation value is either a proportional gain or a differential gain, the gain used is decreased and the integral gain is maintained or reduced as it is,
   A slip control device, comprising: a feedback gain changing unit that maximizes the after-reduction ratio of the integral gain among the after-reduction ratio that is the ratio of the after-reduction size to the before-reduction size of each gain.
3. The slip control device according to claim 1, wherein the feedback gain changing unit determines whether the vehicle is accelerating or decelerating, and the proportional gain, the integral gain, and the derivative gain at the time of acceleration and at the time of deceleration. The slip control device according to any one or more of the above, wherein the method of reducing the gain to be reduced when the vehicle speed is less than or equal to the threshold value is different.
4. The slip control device according to claim 2, wherein the feedback gain changing unit determines whether the vehicle is accelerating or decelerating, and the proportional gain, the integral gain, and the derivative gain at the time of acceleration and at the time of deceleration. The slip control device according to any one or more of the above, wherein the method of reducing the gain to be reduced when the vehicle speed is less than or equal to the threshold value is different.
5. In the slip control device according to claim 1 or 3, further,
   An allowable rotation speed acquisition unit that acquires the allowable wheel rotation speed from detection values of state quantities of factors of a vehicle that affect slip by applying a defined rule;
   A wheel rotation speed deviation calculation unit that calculates the wheel rotation speed deviation;
   A controller for obtaining the feedback calculation value from the wheel rotational speed deviation using variable gains respectively performing the integral compensation and proportional compensation and / or derivative compensation;
   And a braking / driving command value calculation unit that changes the input braking / driving command value using the feedback calculation value and outputs the same to the controller of the motor.
   The said feedback gain change part makes a value which divided the ratio after change of proportional gain or derivative gain by ratio after the fall of integral gain smaller than the time of acceleration in the same vehicle speed, when the vehicle is decelerating. Control device.
6. In the slip control device according to claim 2 or 4, further,
   A slip ratio calculation unit that calculates a slip ratio from the wheel rotational speed and the vehicle speed;
   A slip ratio deviation calculation unit that calculates the slip ratio deviation;
   A controller for acquiring the feedback calculation value from the slip ratio deviation using variable gains respectively performing the integral compensation and proportional compensation and / or derivative compensation;
   And a braking / driving command value calculation unit that changes the input braking / driving command value using the feedback calculation value and outputs the same to the controller of the motor.
   The said feedback gain change part makes a value which divided the ratio after change of proportional gain or derivative gain by ratio after the fall of integral gain smaller than the time of acceleration in the same vehicle speed, when the vehicle is decelerating. Control device.
7. The slip control device according to any one of claims 1 to 6, wherein the feedback gain changing unit is configured to set one or both of a proportional gain and a differential gain when the vehicle speed is less than or equal to the threshold. A slip control device that changes the value to zero, or close to zero.
8. The slip control device according to any one of claims 1 to 7, wherein the vehicle is provided with a plurality of drive wheels independently and controllably, and the electric motor corresponds to one of the plurality of drive wheels. A slip control device configured to drive a drive wheel.
   

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