JP5310142B2 - Vehicle driving force control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving force controller for vehicles wherein even when the longitudinal force of either of left and right wheels is saturated, vehicle body vibration arising from input disturbance can be suppressed. <P>SOLUTION: The driving force controller is provided with left and right motors 1, 2 that independently drive the left and right wheels 12, 13, disturbance detectors 3, 4 that detect the input disturbances D<SB>R</SB>^, D<SB>L</SB>^ of the left and right wheels 1, 2, disturbance suppression torque computation units 5, 6 that compute disturbance suppression torques T<SB>R</SB><SP>*</SP>, T<SB>L</SB><SP>*</SP>for suppressing the input disturbances D<SB>R</SB>^, D<SB>L</SB>^, control error computation units 7, 8 that estimate control errors E<SB>R</SB>, E<SB>L</SB>from the disturbances D<SB>R</SB>^, D<SB>L</SB>^ and the disturbance suppression torques T<SB>R</SB><SP>*</SP>, T<SB>L</SB><SP>*</SP>, and a torque correction unit 9 that corrects the disturbance suppression torques T<SB>R</SB><SP>*</SP>, T<SB>L</SB><SP>*</SP>so as to cancel out the control errors E<SB>R</SB>, E<SB>L</SB>. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a vehicle driving force control apparatus.

  In the conventional vehicle driving force control device, the unsprung vibration is suppressed by canceling the wheel speed fluctuation caused by the disturbance input from the road surface to the wheel by the disturbance suppression torque of the motor. An example of a technique related to this description is disclosed in Patent Document 1.

JP 2007-261477 A

  However, in the above prior art, when the longitudinal force of one of the left and right wheels is saturated and the output torque of the motor is less than the disturbance suppression torque, the unsprung vibration is transmitted to the spring and the body vibration is generated. There was a problem to do.

  An object of the present invention is to provide a vehicular driving force control device that can suppress vehicle body vibration accompanying an input disturbance even when the longitudinal force of one of the left and right wheels is saturated.

In the present invention, when it is determined that the longitudinal force of one of the left and right wheels is saturated, vibration generated in the vehicle body due to the saturation is suppressed by the motor torque of the wheel that is not saturated or the combined torque of the left and right motor torques. The left wheel motor torque command value and the right wheel motor torque command value are corrected.

Therefore, even if one of the longitudinal force of the left and right wheel is saturated, it is possible to suppress the vehicle vibration due to input disturbances.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a vehicle drive system showing a vehicle drive force control apparatus according to a first embodiment. FIG. 5 is a control block diagram of a control error calculation unit 7 for the right wheel according to the first embodiment. FIG. 3 is a control block diagram of a torque correction unit 9 according to the first embodiment. 6 is a flowchart illustrating a flow of a correction torque calculation process executed by the torque distributor 33 according to the first embodiment. 1 is a vehicle model according to a first embodiment. It is a block diagram of a vehicle model. FIG. 10 is a control block diagram of a torque correction unit 9 according to a third embodiment. FIG. 10 is a control block diagram of a torque distributor 33 according to a third embodiment. It is a vibration transmission characteristic diagram of yaw rate vibration and vehicle body longitudinal vibration.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the driving force control apparatus for vehicles of this invention is demonstrated by the Example based on drawing.

First, the configuration will be described.
[overall structure]
FIG. 1 is a schematic diagram of a vehicle drive system showing a vehicle driving force control apparatus according to a first embodiment. The vehicle according to the first embodiment is a front-wheel drive vehicle in which left and right rear wheels are independently motor-driven. Hereinafter, the right rear wheel and the left rear wheel are simply referred to as the right wheel and the left wheel. It is called the left wheel. In the following description and drawings, R added to the parameters and symbols represents the right wheel, and L represents the left wheel.

  The vehicle driving force control apparatus according to the first embodiment includes a right wheel motor 1, a left wheel motor 2, a disturbance detector (disturbance detection means) 3, a disturbance detector (disturbance detection means) 4, and a disturbance suppression torque calculator. (Disturbance suppression torque calculation means) 5, disturbance suppression torque calculation section (disturbance suppression torque calculation means) 6, control error calculation section (error estimation means) 7, control error calculation section (error estimation means) 8, torque A correction unit (torque correction means) 9, an adder 10, and an adder 11 are provided.

The right wheel motor 1 rotates the right wheel 12 according to the motor torque command value _TMR of the right wheel 12. The left wheel motor 2 rotates the left wheel 13 in response to the motor torque command value T _ML of the left wheel 13. In the first embodiment, in-wheel motors are used as the right wheel motor 1 and the left wheel motor 2.
The disturbance detector 3 detects an input disturbance D _R for the tire of the right wheel 12. The disturbance detector 4 detects an input disturbance D _L for the tire of the left wheel 13.

The disturbance suppression torque calculator 5 calculates a disturbance suppression torque T _R ^* that suppresses the input disturbance D _R ^ based on the input disturbance D _R ^ detected by the disturbance detector 3 of the right wheel 12. Disturbance suppression torque calculation unit 6, based on the input disturbance D _L ^ detected by the disturbance detector 4 of the left wheel 13 is calculated the input disturbance D _L ^ suppressing disturbance suppression torque T _L ^*.

The control error calculation unit 7 calculates a control error E _R for the input disturbance of the right wheel 12 from the input disturbance D _R and the disturbance suppression torque T _R ^* . The control error calculation unit 8 calculates a control error E _L for the input disturbance of the left wheel 13 from the input disturbance D _L and the disturbance suppression torque T _L ^* .
The torque correction unit 9 corrects the disturbance suppression torque T _R ^* from the control error E _R and corrects the disturbance suppression torque T _L ^* from the control error E _L.

The adder 10 adds the torque command value (requested motor torque) T _{BR of} the right wheel motor 1 according to the accelerator operation of the driver and the corrected disturbance suppression torque T _R to add the motor torque command of the right wheel motor 1 Calculate the value _TMR . The adder 11, the torque command value of the left wheel motor 2 in response to the accelerator operation of the driver (required motor torque) T _BL and, the left wheel motor 2 by adding the disturbance suppression torque T _L of the corrected motor torque command value T Calculate _ML . In the following, for convenience, the motor torque command values T _R and T _L corresponding to the accelerator operation are both assumed to be zero. Therefore, T _R = T _MR and T _L = T _ML .

  Hereinafter, the operation of the disturbance detectors 3 and 4, the disturbance suppression torque calculation units 5 and 6, the control error calculation units 7 and 8 and the torque correction unit 9 will be described in detail. Since the units 5 and 6 and the control error calculation units 7 and 8 have the same configuration on the left and right, only the right wheel side will be described, and the description on the left wheel side will be omitted.

[Disturbance detector]
The disturbance detector 3 detects an input disturbance D _R ^ received by the tire from the ground. If it cannot be detected directly, the acceleration A _R is detected by a G sensor (not shown) provided below the spring (position on the wheel side of the suspension), and the input disturbance D _R ^ is estimated from the following equation (1).
DR ^ = N _R A _R … (1)
However, N _R (s) is a vibration transmission characteristic from the acceleration A _R to the tire ground contact surface (input disturbance D _R ). Incidentally, N _R than to align the units, no problem be treated equivalent to M _R, which will be described later.

[Disturbance suppression torque calculator]
The disturbance suppression torque calculator 5 calculates a disturbance suppression torque T _R ^* according to the input disturbance D _R ^ detected by the disturbance detector 3. The vibration transfer characteristic from the motor torque command value T _R to the tire ground contact surface (input disturbance D _R ) is defined as M _R (M _R = M _{L in the} first embodiment from the left-right symmetry). It calculates the controller K _R.
K _R = F _R M _R ^-1 (2)
However, F _R is a filter for proper the controller, the disturbance suppressing performance is determined by the design of F _R.

ここで、W_Zは入力外乱の抑制性能に関する重みを表し、W_uは操作量に対する重みを表す。これにより、重み関数を設計するだけで最適なコントローラ設計が可能となる。
以上導出されたコントローラを用いると、外乱抑制トルクT_R ^*は下記の式(4)から演算できる。
T_R ^* = -K_RD_R^ …(4) If the formula (2) Design is difficult, as shown in the following equation (3), it may derive the controller K _R that minimizes and H ₂ norm for the input disturbance.

Here, W _Z represents a weight related to the input disturbance suppression performance, and W _u represents a weight for the operation amount. This makes it possible to design an optimal controller simply by designing a weight function.
When the controller derived above is used, the disturbance suppression torque T _R ^* can be calculated from the following equation (4).
T _R ^* = -K _R D _R ^… (4)

[Control error calculation section]
FIG. 2 is a control block diagram of the right wheel control error calculator 7 of the first embodiment, and the control error calculator 7 includes a motor torque converter 21 and a tire control error calculator 22.
The motor torque converter 21 converts the input disturbance D _R ^ into a motor torque converted value D _mR ^ from the following equation (5).
D _mR ^ = M _R ^-1 D _R ^… (5)

The control error calculation unit 22 calculates a control error E _R for the input disturbance from the disturbance suppression torque T _R ^* and the motor torque converted value D _mR ^.
In order to calculate the control error E _R , first consider the following equation (1) considering the motor drive torque maximum value T _{mR_SAT +, the} regenerative torque maximum value T _{mR_SAT-} , and the tire friction circle μW _R determined by the battery capacity and hardware characteristics: The maximum motor torque T _{mR_SAT} that can be transmitted to the ground is derived from 6) and (7).
T _{mR_SAT +} = min [T _{R_SAT +} , μW _R ]… (6)
T _{nR_SAT-} = max [T _{R_SAT-} , -μW _R ]… (7)
Here, M _R is the vibration transmission characteristic from the motor torque command value T _R to the tire ground contact surface. The driving torque is a positive value and the regenerative torque is a negative value.

Next, a control error E _R is calculated from T _{mR_SAT +} and T _{nR_SAT− according} to Expression (8).
E _R = D _mR ^ -sat [T _R ^* | T _{mR_SAT-} , T _{mR_SAT +} ]… (8)
However, the sat function is defined as in the following equation (9).

That is, in Equation (8), when T _R ^* is T _{mR_SAT-} or less, the control error E _R is a value _obtained by subtracting T _{mR_SAT-} from D _mR ^, T _R ^* is _greater than T _{mR_SAT-} , and If _{R m} is smaller than T _{mR_SAT +} , E _R is a value obtained by subtracting T _R ^* from D _mR ^, and if T _R ^* is _{equal to} or greater than T _{mR_SAT +} , E _R is a value _obtained by subtracting T _{mR_SAT +} from D _mR ^.

[Torque correction part]
FIG. 3 is a control block diagram of the torque correction unit 9 according to the first embodiment. The torque correction unit 9 includes a yaw resonance frequency extraction unit 31, a yaw resonance frequency extraction unit 32, a torque distributor 33, and an adder 34. And an adder 35.

Yaw resonance frequency extracting unit 31 extracts the component around the yaw resonance frequency band-pass filter BPF from the control error E _R. Here, the band of the bandpass filter BPF is derived from the vibration transfer characteristic G _R or G _{L with} the yaw resonance frequency f _r (for example, 2 Hz), and f _r -a to f _r + a with f _r as the center. It is set (for example, a = 1 Hz). The configuration of the yaw resonance frequency extraction unit 32 is the same as that of the yaw resonance frequency extraction unit 31, and thus the description thereof is omitted.

The torque distributor 33 calculates correction torques ΔT _R ^* , ΔT _L ^* for the left and right wheel disturbance suppression torques T _R ^* , T _L ^* from the extracted control errors E _R ^* , E _L ^* .
FIG. 4 is a flowchart showing the flow of the correction torque calculation process executed by the torque distributor 33, and each step will be described below.
In step S1, correction torques ΔT _R ^* and ΔT _L ^* are calculated from control errors E _R ^* and E _L ^* after extracting components near the yaw resonance frequency, and the process proceeds to step S2.
The correction torques ΔT _R ^* and ΔT _L ^* are considered so as not to generate yaw rate vibration. For example, ΔT _R ^* and ΔT _L ^* are distributed as in the following formulas (10) and (11).
δT _R ^* = -E _L ^* … (10)
δT _L ^* = -E _R ^* … (11)

In step S2, the longitudinal force saturation of the wheel is calculated from the following equations (12) and (13), and the process proceeds to step S3.
sat [T _R ^* + δT _R ^* | T _{mR_SAT-} , T _{mR_SAT +} ]… (12)
sat [T _L ^* + δT _L ^* | T _{mL_SAT-} , T _{mL_SAT +} ]… (13)

In step S3, saturation is determined. If saturation is assumed in either one of the left and right wheels, the process proceeds to step S4. If saturation is not assumed, this control is terminated. In this step, for example, in the case of the right wheel 12, when the corrected disturbance suppression torque T _R ^* + δT _R ^* exceeds the drive torque maximum value T _{mR_SAT +} of the right wheel motor 1, or falls below the regenerative torque maximum value T _{mR_SAT-} Is determined to be saturated.

In step S4, the correction torque is recalculated from the following equations (14) and (15), and the process proceeds to step S2.
δT _R ^* = -E _L ^* + δE × N (14)
δT _L ^* = -E _R ^* + δE × N… (15)
Here, N is the number of recalculations of the correction torque, and is incremented by 1 for each recalculation, assuming an initial value of zero. Further, ΔE is the minimum value of the correction torque, and is set to about 1N, for example.
Returning to FIG. 3, the adder 34 calculates the corrected disturbance suppression torque by adding T _R ^* and δT _R ^* as shown in the following equation (16).
T _R = T _R ^* + δT _R (16)
Since the configuration of the adder 35 is the same as that of the adder 34, the description thereof is omitted.

Next, the operation will be described.
[Vibration suppression logic when one wheel is saturated]
FIG. 5 shows a vehicle model of the first embodiment. For example, an input disturbance D _R that is input to the right wheel motor 1 is assumed to suppress availability disturbance suppression torque T _R of the right wheel motor 1. If saturation, etc. of the motor torque that can not be completely suppressed D _R> T _R, whereby the input disturbance, [Delta] [gamma] in the yaw rate direction, the vibration in the longitudinal direction .delta.a _x generated in the vehicle body 14 by the control error E _R.

Now, in each of the left and right wheels 12 and 13, the vibration transfer characteristics from the input disturbance to the vehicle body yaw rate δγ are G _R and G _L , the vibration transfer characteristics from the input disturbance to the vehicle body longitudinal vibration δa _x are H _R and H _L , and the motor torque The vibration transfer characteristics from the command value to the tire contact surface are M _R and M _L. The vehicle model at this time can be expressed as shown in FIG. Further, assuming that the left and right wheels have the same vibration transfer characteristics, the vehicle behavior change due to the input disturbance can be expressed by the following equations (17) and (18).
δγ = (D _R -M _R T _R ) G _R -M _L T _L G _R (17)
δa _x = (D _R -M _R T _R ) H _R + M _L T _L H _R (18)
However, the input disturbance D _L of the left wheel is zero, G _R = G _L , H _R = −H _L.
Thus, [Delta] [gamma] = 0, i.e., in order to cancel the yaw rate oscillation [Delta] [gamma] from equation (17), may be given a _{T L = (D R -T R} M R) / M L become torque left wheel motor 2.

[Vibration suppression action]
In the vehicle driving force control apparatus according to the first embodiment, the disturbance detectors 3 and 4 detect the input disturbances D _R ^ and D _L ^ that the tire receives from the ground, and the disturbance suppression torque calculation units 5 and 6 input the disturbance D _R. Disturbance suppression torques T _R ^* and T _L ^* for canceling ^, D _L ^ are calculated. Subsequently, the control error calculation units 7 and 8 subtract the torque that the motor can actually output from the motor torque conversion values D _mR ^ and D _mL ^ of the input disturbances D _R ^ and D _L ^ to _reduce the input disturbance. The control errors E _R and E _L are calculated (see formula (8)). That is, the control errors E _R and E _L are torque inputs to the vehicle body that cause changes in vehicle behavior.

Therefore, the torque distributor 33 of the torque correction unit 9 adds the correction torque ΔT _L ^* = − E _R ^* that cancels the control error E _R on the right wheel 12 side to the disturbance suppression torque T _L ^* of the left motor 2, The correction torque ΔT _R ^* = − E _L ^* that cancels the control error E _L on the left wheel 13 side is added to the disturbance suppression torque T _R ^* of the right motor 1. Thereby, the control errors E _R and E _L with respect to the input disturbance can be canceled, and the vehicle body vibration can be suppressed.

Further, in the torque correction unit 9, the yaw resonance frequency extraction units 31 and 32 that extract components near the yaw resonance frequency from the control errors E _R and E _L using the bandpass filter BPF are provided before the torque distributor 33. The torque distributor 33 calculates correction torques ΔT _R ^* and ΔT _L ^* that cancel out the control errors E _R and E _L obtained by extracting components near the yaw resonance frequency.

Since the input disturbances D _R ^ and D _L ^ are particularly amplified at the resonance frequency, by canceling the control errors E _R and E _L that extract the components near the yaw resonance frequency, particularly the yaw rate that amplifies the input disturbance Resonance can be suppressed and vehicle body vibration can be effectively suppressed.

[Vibration suppression action when wheels are saturated]
In the correction torque calculation process of the torque distributor 33, if it is determined in step S2 that the longitudinal force of at least one of the left and right wheels 12, 13 is saturated from the expressions (12), (13), the process proceeds to step S4. Correction is performed by adding ΔE × N (N is the number of recalculations) to the correction torques ΔT _R ^* , ΔT _L ^* . The correction torque recalculation in step S4 is performed until it is determined that the saturation is not saturated in step S2, that is, the corrected disturbance suppression torque T _R ^* + δT _R ^{* of} the right wheel motor 1 is between T _{mR_SAT-} and T _{mR_SAT +} . The range is continued until the corrected disturbance suppression torque T _L ^* + δT _L ^{* of the} left wheel motor 2 is in a range between T _{mL_SAT−} and T _{mL_SAT +} .

  As a result, the yaw rate vibration δγ generated in the vehicle body due to saturation of the longitudinal force of one of the left and right wheels 12 and 13 can be suppressed by the motor torque of the wheel that is not saturated, or the combined torque of the left and right motor torques. Can be prevented.

Next, the effect will be described.
The vehicle driving force control apparatus according to the first embodiment has the following effects.
(1) Left and right motors 1 and 2 that drive left and right wheels 12 and 13 independently, disturbance detectors 3 and 4 that detect input disturbances D _R ^ and D _L ^ for left and right wheels 1 and 2, and input disturbances D _R ^, D _L suppresses ^ disturbance suppression torque T _R ^*, a disturbance suppression torque calculation unit 5, 6 for calculating the T _L ^*, disturbance D _R ^, D _L ^ and disturbance suppression torque T _R ^*, T _L ^* control error E _R and a, and the control error calculation unit 7, 8 to estimate E _L, control error E _R, disturbance suppression torque T _R ^* to cancel the E _L, a torque correction unit 9 which corrects the T _L ^* , With. As a result, even when the longitudinal force of one of the left and right wheels is saturated, the body vibration caused by the input disturbances D _R ^, D _L ^ can be suppressed by the disturbance suppression torque of the other wheel, and the vehicle control performance is deteriorated and Deterioration of ride comfort can be prevented.

(2) torque correcting unit 9, an input disturbance D _R ^, and yaw resonance frequency extracting unit 31 for extracting a resonant frequency f _r of the vibration transmission characteristic from D _L ^ to the vehicle body yaw rate oscillation [Delta] [gamma], have been extracted yaw resonance frequency f _r given frequency band centered around the f _r -a~f _r + a disturbance suppressing torque to suppress yaw oscillation in T _R ^*, the torque distributor 33 for correcting the T _L ^*, a Prepare. Thereby, it is possible to suppress the yaw rate resonance that particularly amplifies the input disturbance.

  The vehicle driving force control apparatus according to the second embodiment is different from the first embodiment in the method of calculating the correction torque in the torque distributor 33. Since the other configuration is the same as that of the first embodiment, illustration and description of configurations other than the torque distributor 33 are omitted.

First, the configuration will be described.
[Torque distributor]
When the torque distributor 33 according to the second embodiment calculates the correction torques δT _R ^* and δT _L ^* from the control errors E _R ^* and E _L ^* , the left and right wheels 12 and 13 carry out the amount of electric power taken out from the battery (not shown). The correction torques ΔT _R ^* and ΔT _L ^* are set so that becomes zero and does not generate the yaw rate vibration Δγ. For example, the correction torques ΔT _R ^* and ΔT _L ^* are distributed as in the following equations (19) and (20).
δT _R ^* = {(-T _R ^* + E _R ^* ) / 2}-{(T _L ^* + E _L ^* ) / 2}… (19)
δT _L ^* = {(-T _L ^* + E _L ^* ) / 2}-{(T _R ^* + E _R ^* ) / 2}… (20)

Next, the operation will be described.
[Battery current suppression]
In the second embodiment, since the correction torques δT _R ^* and δT _L ^* are set as in the equations (19) and (20), the correction torque δT _R ^* of the right wheel motor 1 and the correction torque δT _L ^{* of} the left wheel motor 2 The value obtained by adding is zero. Here, when the correction torque δT _R ^* is the driving torque and the correction torque δT _L ^* is the regenerative torque, the power required for the correction torque δT _R ^* is due to the regenerative power generation of the left wheel motor 2 by the correction torque δT _L ^*. It can be covered by stored electricity. Therefore, the battery current consumption when suppressing the yaw rate vibration δγ can be minimized.

Next, the effect will be described.
The vehicle driving force control apparatus according to the second embodiment has the following effects in addition to the effects (1) and (2) of the first embodiment.
(3) The torque correction unit 9 corrects the disturbance suppression torques δT _R ^* and δT _L ^* so that the added value δT _R ^* + δT _L ^* of the disturbance suppression torque of the left and right wheels 12 and 13 becomes zero. Battery current consumption during suppression of vibration δγ can be minimized, and fuel consumption can be improved.

  The vehicle driving force control apparatus according to the third embodiment is different from the first embodiment in the configuration of the torque correction unit 9. Since the other configuration is the same as that of the first embodiment, illustration and description of configurations other than the torque correction unit 9 are omitted.

First, the configuration will be described.
[Torque correction part]

FIG. 7 is a control block diagram of the torque correction unit 9 according to the third embodiment.
The torque correction unit 9 according to the third embodiment includes a yaw resonance frequency extraction unit 31, a yaw resonance frequency extraction unit 32, a front / rear resonance frequency extraction unit 36, and a front / rear resonance frequency extraction unit 37.
The yaw resonance frequency extraction unit 31 extracts a component around the yaw resonance frequency (yaw resonance control error E _Rγ ^* ) from the control error E _R. The yaw resonance frequency extraction unit 32 extracts a component (yaw resonance control error E _Lγ ^* ) with a yaw resonance frequency added from the control error E _L.

Longitudinal resonance frequency extracting unit 36 extracts the component around the longitudinal resonance frequency from the control error E _R by the band-pass filter BPF. Here, the band of the bandpass filter BPF is derived from the vibration transfer characteristics H _R or H _L from the front-rear resonance frequency f _r (for example, 30 Hz), and is in the range of f _ax -b to f _ax + b with f _ax as the center. Set (for example, b = 5 Hz). Note that the configuration of the front-rear resonance frequency extraction unit 37 is the same as that of the front-rear resonance frequency extraction unit 36, and thus the description thereof is omitted.

[Torque distributor]
FIG. 8 is a control block diagram of the torque distributor 33 according to the third embodiment. The torque distributor 33 includes a yaw vibration suppression distributor 41, a vehicle body longitudinal vibration suppression distributor 42, an adder 43, and an adder 44. With.

Yaw vibration suppression distributor 41, the yaw resonance control error E _{Rγ ^*,} E ^{Lγ *} correction for yaw resonance from a torque? T _R? ^*, Calculates the _δT Lγ ^*. Correction torque is considered so as not to generate the yaw rate oscillation, for example _δT Rγ ^*, δT Lγ ^* is the following formula (21), is distributed as (22).
^{_{δT Rγ * = -E Lγ * ...}} (21)
^{_{δT Lγ * = -E Rγ * ...}} (22)

The vehicle body longitudinal vibration suppression distributor 42 calculates correction torques ΔT _Rax ^* and ΔT _Lax ^* related to the longitudinal resonance from the longitudinal resonance control errors E _Rax ^* and E _Lax ^* . The correction torque is considered so as not to generate the longitudinal vibration of the vehicle body. For example, ΔT _Rax ^* and ΔT _Lax ^* are distributed as in the following formulas (23) and (24).
δT _Rax ^* = + E _Lax ^* … (23)
δT _Lax ^* = + E _Rax ^* … (24)

The adder 43 and the adder 44 calculate the correction torque from the following equations (25) and (26).
_{^{δT R * = δT Rγ * +}} δT Rax * ... (25)
δT _L ^* = δT _Lγ ^* + δT _Lax ^* … (26)

Returning to FIG. 8, the adder 34 calculates the disturbance suppression torque T _R of the right wheel after correction from the following equation (27).
T _R = T _R ^* + δT _R ^* … (27)
The adder 35 calculates the corrected disturbance suppression torque T _L for the left wheel from the following equation (28).
T _L = T _L ^* + δT _L ^* (28)

Next, the operation will be described.
[Vibration suppression action]
As described above, in order to cancel the yaw rate vibration δγ associated with the input disturbance of the right wheel 12, torque equal to T _L = (D _R -T _R M _R ) / M _L is applied to the left wheel motor 2 from the equation (17). Should be given.
On the other hand, in order to cancel the vehicle body longitudinal vibration δa _x due to the input disturbance of the right wheel 12, it is only necessary to give a torque _satisfying T _L = (− D _R + T _R M _R ) / M _L in equation (18). . As a result, δa _x = 0 and the vehicle body longitudinal vibration δa _x can be suppressed.

However, as shown in FIG. 9, the yaw rate vibration characteristic G has a resonance frequency at the frequency f _r , and the vehicle body longitudinal vibration characteristic H has a resonance frequency at the frequency f _ax , and these two resonance frequencies f _r , f _ax Is f _r ≠ f _ax (eg, f _r = 2 Hz, f _ax = 30 Hz). Therefore, it is difficult to simultaneously suppress the yaw oscillation δγ and body longitudinal vibration .delta.a _x.

On the other hand, in the third embodiment, the torque correction unit 9 extracts a component in the vicinity of the yaw resonance frequency from the control errors E _R and E _L using the bandpass filter BPF before the torque distributor 33. Extraction units 31 and 32 and front and rear resonance frequency extraction units 36 and 37 that extract components near the front and rear resonance frequency from the control errors E _R and E _L using a bandpass filter BPF are provided.

Further, in the torque distributor 33, the yaw resonance control error by the yaw oscillation suppression distributor 41 E _{Rγ ^*,} E ^{Lγ *} correction for yaw resonance from a torque? T _R? ^*, Calculates the _δT Lγ ^*, the vehicle body longitudinal vibration suppression distributor 42, correction torques ΔT _Rax ^* and ΔT _Lax ^* related to the longitudinal resonance are calculated from the longitudinal resonance control errors E _Rax ^* and E _Lax ^* . Then, to calculate the right wheel motor 1? T _R ^* by adding the? T _R? ^* And? T _Rax ^*, calculates the _δT Lγ ^* and? T _Lax ^* and the left wheel motor 2 by adding? T _L ^*.

Therefore, for the yaw rate oscillation δγ yaw resonance frequency f _r, by suppressing the longitudinal resonance frequency f _ax for vehicle longitudinal vibrations a _x, a yaw rate oscillation δγ and body longitudinal vibration .delta.a _x can be simultaneously suppressed.

Next, the effect will be described.
The vehicle driving force control apparatus according to the third embodiment has the following effects in addition to the effects (1) and (2) of the first embodiment.
(4) The torque correction unit 9 is extracted with the longitudinal resonance frequency extraction units 36 and 37 that calculate the resonance frequency f _ax of the vibration transfer characteristic from the input disturbances D _R and D _L to the vehicle body longitudinal vibration δa _x of the vehicle body. longitudinal resonance frequency f _ax predetermined frequency band centered around the f _ax -b~f _ax + b disturbance suppressing torque so as to inhibit the vehicle body longitudinal vibrations .delta.a _x with T _R ^*, the torque distributor 33 for correcting the T _L ^* And comprising. Thereby, the resonance in the longitudinal direction of the vehicle body, in particular, where the input disturbance is amplified can be suppressed.

(5) torque correction unit 9, an input disturbance D _R ^, and yaw resonance frequency extracting unit 31 for extracting a resonant frequency f _r of the vibration transmission characteristic from D _L ^ to the vehicle body yaw rate oscillation [Delta] [gamma], an input disturbance D _R, predetermined frequency around the longitudinal resonance frequency extracting unit 36, extracted yaw resonance frequency f _r for calculating the resonant frequency f _ax of the vibration transmission characteristic from D _L to the vehicle longitudinal vibrations .delta.a _x of the vehicle body suppressing yaw rate oscillation in the band f _r -a~f _r + a, and suppress the vehicle body longitudinal vibrations in the extracted longitudinal resonance frequency f _ax around a predetermined frequency band f _ax -b~f _ax + b And a torque distributor 33 that corrects the disturbance suppression torques T _R ^* and T _L ^* . Thus, the yaw rate oscillation δγ and body longitudinal vibration .delta.a _x can be simultaneously suppressed.

(Other examples)
The best mode for carrying out the present invention has been described above based on the embodiments. However, the specific configuration of the present invention is not limited to the embodiments and is within the scope of the invention. Any design changes are included in the present invention.
For example, in the embodiment, an example in which the present invention is applied to a rear wheel drive vehicle has been shown. However, the present invention can also be applied to a front wheel drive vehicle and a four wheel drive vehicle, and the same effects as the embodiment can be obtained. it can.

1 Right wheel motor
2 Left wheel motor
3 Disturbance detector (disturbance detection means)
4 Disturbance detector (disturbance detection means)
5 Disturbance suppression torque calculator (disturbance suppression torque calculation means)
6 Disturbance suppression torque calculation unit (disturbance suppression torque calculation means)
7 Control error calculator (vehicle behavior change estimation means)
8 Control error calculator (vehicle behavior change estimation means)
9 Torque correction unit (torque correction means)
12 Right drive wheel
13 Left drive wheel

Claims (6)

And the left wheel motor for driving the left wheel,
A right wheel motor that drives the right wheel;
A left wheel disturbance detection means for detecting an input disturbance of the left wheel,
Right wheel disturbance detection means for detecting the input disturbance of the right wheel;
A left wheel disturbance suppression torque calculating means for calculating a suppressing left wheel disturbance suppression torque input disturbance of the left wheel,
A right wheel disturbance suppression torque calculating means for calculating a right wheel disturbance suppression torque for suppressing the input disturbance of the right wheel;
Left wheel motor torque command value calculation means for calculating the left wheel motor torque command value by adding the left wheel disturbance suppression torque to the left wheel request motor torque;
Right wheel motor torque command value calculation means for calculating the right wheel motor torque command value by adding the right wheel disturbance suppression torque to the right wheel request motor torque;
Longitudinal force saturation judging means for judging whether or not the longitudinal force of at least one of the left and right wheels is saturated when the left wheel motor and the right wheel motor are driven by the left wheel motor torque command value and the right wheel motor torque command value. When,
When it is determined that the longitudinal force of one of the left and right wheels is saturated, the left wheel motor is configured to suppress the vibration generated in the vehicle body due to the saturation by the motor torque of the wheel that is not saturated or the combined torque of the left and right motor torques. Torque correction means for correcting the torque command value and the right wheel motor torque command value ;
A vehicle driving force control apparatus comprising: The vehicle driving force control device according to claim 1,
Left wheel control error estimation means for estimating a control error for the left wheel input disturbance from the left wheel input disturbance and the left wheel disturbance suppression torque;
Right wheel control error estimation means for estimating a control error for the right wheel input disturbance from the right wheel input disturbance and the right wheel disturbance suppression torque;
With
The torque correcting means performs initial correction for adding a correction torque for canceling the left wheel control error to the right wheel disturbance suppression torque and adding a correction torque for canceling the right wheel control error to the left wheel disturbance suppression torque. When it is determined that the longitudinal force of one of the left and right wheels is saturated after the initial correction, the left wheel disturbance suppression torque is canceled so that both the left wheel control error and the right wheel control error are canceled and the saturation is eliminated. And correct the right wheel disturbance suppression torque,
The left wheel motor torque command value calculation means calculates the left wheel motor torque command value based on the left wheel disturbance suppression torque corrected by the torque correction means,
The right wheel motor torque command value calculating means calculates the right wheel motor torque command value based on the right wheel disturbance suppression torque corrected by the torque correcting means. In the vehicle driving force control device according to claim 2 ,
The torque correction means includes
A yaw resonance frequency extraction unit for extracting a resonance frequency of a vibration transfer characteristic from an input disturbance to a yaw rate vibration of the vehicle body;
A torque distributor for correcting the left wheel disturbance suppression torque and the right wheel disturbance suppression torque so as to suppress yaw rate vibration in a predetermined frequency band centered on the extracted yaw resonance frequency;
A vehicle driving force control device comprising: In the vehicle driving force control device according to claim 2 ,
The torque correction means includes
A longitudinal resonance frequency extraction unit for calculating a resonance frequency of a vibration transfer characteristic from an input disturbance to a longitudinal vibration of the vehicle body;
A torque distributor for correcting the left wheel disturbance suppression torque and the right wheel disturbance suppression torque so as to suppress vehicle body longitudinal vibration in a predetermined frequency band centered on the extracted longitudinal resonance frequency;
A vehicle driving force control device comprising: In the vehicle driving force control device according to claim 2 ,
The torque correction means includes
A yaw resonance frequency extraction unit for extracting a resonance frequency of a vibration transfer characteristic from an input disturbance to a yaw rate vibration of the vehicle body;
A longitudinal resonance frequency extraction unit for calculating a resonance frequency of a vibration transfer characteristic from an input disturbance to a longitudinal vibration of the vehicle body;
The left wheel disturbance suppression to suppress yaw rate vibration in a predetermined frequency band centered on the extracted yaw resonance frequency, and to suppress vehicle body longitudinal vibration in a predetermined frequency band centered on the extracted front-rear resonance frequency A torque distributor for correcting the torque and the right wheel disturbance suppression torque;
A vehicle driving force control device comprising: In the vehicle driving force control device according to claim 2, 3 or 5,
  The vehicle driving force control device according to claim 1, wherein the torque correction unit corrects the left wheel disturbance suppression torque and the right wheel disturbance suppression torque so that an added value of the disturbance suppression torques of the left and right wheels becomes zero.

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