Control method for electric vehicle and control device for electric vehicle

Abstract

To provide a control method for electric vehicle and a control device for electric vehicle that can suppress vibrations that a vehicle has even when one drive shaft comprises a drive power transmission mechanism which transmits composite power of a plurality of electric motors to drive wheels.SOLUTION: When a drive power transmission mechanism inputs a total torque quantity which is the sum of torque command values to a vehicle model obtained by modeling characteristics assuming that a plurality of electric motors are a body of inertia which rotates in one body so as to calculate a parameter correlating with rotary motion of the vehicle model, and corrects the total torque quantity based upon a correction quantity obtained by multiplying the parameter by a predetermined gain so that the rotary motion is a norm response, distribution gains summed up to the gain are individually set to the electric motors, and the torque command values are individually corrected based upon a distribution correction quantity obtained by multiplying the parameter by the distribution gains.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a control method for an electric vehicle and a control device for an electric vehicle. [Background technology]

[0002] Patent Document 1 discloses a technique for suppressing vibrations occurring in a vehicle by taking into consideration the transmission characteristics of a driving force transmission mechanism connected between the output shaft of a motor and the drive wheels. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2013 / 157315 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, motor control is performed based on a vehicle model that models the transmission characteristics of the driving force transmission mechanism and the motor characteristics. Therefore, in a configuration in which multiple motors are connected to the same drive shaft, if control to suppress vibrations individually is applied to each motor, the output torques of the motors affect each other, making it difficult to suppress vibrations.

[0005] The present invention aims to provide a control method for an electric vehicle and a control device for an electric vehicle that can suppress vibrations generated in the vehicle even when the vehicle is equipped with a driving force transmission mechanism that combines the power of multiple electric motors on one drive shaft and transmits the power to the drive wheels. [Means for solving the problem]

[0006] A control method for an electric vehicle according to the present invention includes a driving force transmission mechanism that combines the power of multiple electric motors on one drive shaft and transmits the combined power to drive wheels, sets a torque command value for the electric motor based on vehicle information, and controls the torque of the electric motor based on the torque command value. This control method includes: inputting a total torque amount, which is the sum of the torque command values, into a vehicle model that models the characteristics of the multiple electric motors in the driving force transmission mechanism when they are assumed to be an inertial body that rotates integrally; calculating a parameter correlated with the rotational motion of the vehicle model; and correcting the total torque amount based on a correction amount obtained by multiplying the parameter by a predetermined gain so that the rotational motion becomes a reference response. A distribution gain, which is the sum of the gains, is set individually for the electric motors, and the torque command value is individually corrected based on the distribution correction amount obtained by multiplying the parameter by the distribution gain. [Effects of the Invention]

[0007] According to the present invention, even in a vehicle equipped with a driving force transmission mechanism that combines the power of multiple electric motors on a drive shaft, by simulating an electric motor of a single inertial body that is rigidly connected and rotates substantially integrally, it is possible to perform vibration suppression control using a controller that individually controls each electric motor, just as in the case of a single electric motor on a drive shaft. In this case, parameters correlated with the rotational motion of the driving force transmission system (e.g., motor rotation speed, motor angular acceleration, drive shaft torsional angular velocity, drive shaft torque, etc.) are calculated based on the total torque generated by the multiple electric motors, rather than the torque of each individual electric motor. This enables accurate calculation of the parameters, and effectively suppresses vibrations (especially torsional vibration of the drive shaft) generated in the vehicle without the torque generated by each electric motor acting as a disturbance. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of a basic configuration of a control device for an electric vehicle according to a first embodiment. [Figure 2] FIG. 2 is a diagram showing an example of an accelerator opening-torque table. [Figure 3]FIG. 3 is a flowchart of the motor current control executed by the first motor controller and the second motor controller. [Figure 4] FIG. 4 is a block diagram showing an example of a functional configuration for executing vibration damping control processing in the control device for the electric vehicle of the first embodiment. [Figure 5] FIG. 5 is a diagram showing a model of the driving force transmission system of an electric vehicle. [Figure 6] FIG. 6 is a block diagram of the rotational motion parameter calculator. [Figure 7] FIG. 7 is a block diagram of the F / F compensator. [Figure 8] FIG. 8 is a block diagram of the F / B compensator. [Figure 9] FIG. 9 is a table showing the first drive shaft torsional angular velocity gain and first F / B gain allocated to the first motor controller, and the second drive shaft torsional angular velocity gain and second F / B gain allocated to the second motor controller in the control device for an electric vehicle of the first embodiment. [Figure 10] FIG. 10 is a diagram showing an example of a basic configuration of a control device for an electric vehicle according to the second embodiment. [Figure 11] FIG. 11 is a block diagram showing an example of a functional configuration for executing vibration damping control processing in a control device for an electric vehicle according to the second embodiment. [Figure 12] FIG. 12 is a table showing the first drive shaft torsional angular velocity gain and first F / B gain allocated to the first motor controller, and the second drive shaft torsional angular velocity gain and second F / B gain allocated to the second motor controller in the control device for an electric vehicle of the third embodiment. [Figure 13] FIG. 13 is a table showing the first drive shaft torsional angular velocity gain and first F / B gain allocated to the first motor controller, and the second drive shaft torsional angular velocity gain and second F / B gain allocated to the second motor controller in the control device for an electric vehicle of the fourth embodiment. [Figure 14]FIG. 14 is a graph comparing the time charts for switching from negative torque to positive torque between the conventional technology and this embodiment in the control devices for electric vehicles of the first, third, and fourth embodiments, in which [A] is the total torque amount and torque command value, [B] is the drive shaft torsion angular velocity estimated value, [C] is the motor rotational angular velocity estimated value, [D] is F / F torque, [E] is the final torque command value, [F] is drive shaft torque, [G] is the motor rotational angular velocity detected value, and [H] is F / B torque. [Figure 15] FIG. 15 is a graph comparing the time charts when switching from positive torque (small) to positive torque (large) in the control device for an electric vehicle of the second embodiment between the conventional technology and this embodiment, where [A] is the total torque amount and torque command value, [B] is the motor rotational angular velocity estimated value, [C] is the F / B torque, [D] is the drive shaft torque, and [G] is the motor rotational angular velocity detected value. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0010] [Basic configuration of the first embodiment] FIG. 1 is a diagram showing an example of the basic configuration of a control device for an electric vehicle according to the first embodiment. An electric vehicle to which the control device for an electric vehicle according to the first embodiment is applied includes a driving force transmission mechanism in which two motors (a first motor 8A and a second motor 8B) are coupled to one drive shaft 10 via a reduction gear 9, and drives itself by transmitting the torque of the first motor 8A and the second motor 8B to drive wheels 11A and 11B attached to the drive shaft 10. Note that electric vehicles include not only electric vehicles using the first motor 8A and the second motor 8B as driving force, but also hybrid vehicles and fuel cell vehicles. The control device for an electric vehicle according to the first embodiment controls the first motor 8A and the second motor 8B.

[0011] The control device for an electric vehicle of the first embodiment includes a vehicle controller 1, a first motor controller 2A, a second motor controller 2B, a first inverter 3A, a second inverter 3B, a battery 4, a first current sensor 5A, a second current sensor 5B, a first rotation sensor 6A, a second rotation sensor 6B, and a wheel rotation sensor 7.

[0012] The vehicle controller 1 calculates a total torque T corresponding to the sum of the torques to be instructed to the first motor controller 2A and the second motor controller 2B from the accelerator opening-torque table shown in FIG. 2 based on the vehicle speed V [km / h] obtained from the wheel rotation sensor 7 and the accelerator opening θ [%] obtained from the accelerator opening sensor (not shown). mall * After calculating the total torque T mall * is the first torque command value T m1 * , second torque command value T m2 * and outputs the first torque command value T m1 * and total torque T mall * and the second motor controller 2B is instructed to output the second torque command value T m2 * and total torque T mall * command.

[0013] The first motor controller 2A controls the current of the first motor 8A (i u , i v , iw) and rotor phase α1 are input as digital signals, a PWM signal is generated to control the first motor 8A in accordance with the various vehicle variables, and a drive signal for the first inverter 3A is generated through a drive circuit in accordance with the PWM signal.

[0014] The second motor controller 2B operates independently of the first motor controller 2A, but has the same configuration as the first motor controller 2A.

[0015] The first inverter 3A is configured with, for example, two pairs of switching elements (power semiconductor elements such as IGBTs and MOS-FETs) for each phase, and by turning the switching elements ON / OFF in response to a drive signal, converts the direct current supplied from the battery 4 into alternating current and supplies the desired current to the first motor 8A. Conversely, when regenerative power is generated in the first motor 8A, the first inverter 3A converts the regenerative power into direct current and charges the battery 4.

[0016] The second inverter 3B operates independently of the first inverter 3A, but has the same configuration as the first inverter 3A.

[0017] The battery 4 supplies drive power to the first motor 8A via the first inverter 3A, and to the second motor 8B via the second inverter 3B. The battery 4 is charged with regenerative power generated by the first motor 8A via the first inverter 3A, and is charged with regenerative power generated by the second motor 8B via the second inverter 4B.

[0018] The reducer 9 combines the driving force generated by the first motor 8A and the driving force generated by the second motor 8B, and transmits the driving force to the drive wheels 11A and 11B by driving the drive shaft 10 at a predetermined reduction ratio.

[0019] When the first motor 8A and the second motor 8B rotate in conjunction with the drive wheels 11A and 11B while the vehicle is running, they can generate regenerative driving force, thereby recovering the vehicle's kinetic energy as electrical energy (regenerative power).

[0020] In addition, the first motor 8A is equipped with a first current sensor 5A that detects each phase current and a first rotation sensor 6A (resolver or encoder) that detects the rotor phase α1 of the first motor 8A, and the second motor 8B is equipped with a second current sensor 5B that detects each phase current and a second rotation sensor 6B that detects the rotor phase α2 of the second motor 8B.

[0021] [Motor current control] 3 is a flowchart of the motor current control executed by the first motor controller 2A and the second motor controller 2B. Here, the motor current control by the first motor controller 2A will be explained as an example.

[0022] In the input process of step S301, signals required for the control calculations described below are acquired from sensor inputs or communication from other controllers.

[0023] Three-phase current value i flowing through the first motor 8A u1 ,i v1 ,i w1 is acquired by the first current sensor 5A. Since the sum of the three-phase current values ​​is 0, for example, i w1 is no sensor input, i u1 and i v1 It may be calculated from the value of

[0024] The rotor phase α1 (electrical angle) [rad] of the first motor 8A is acquired by a first rotation sensor 6A such as a resolver or an encoder.

[0025] The rotor angular velocity ω (electrical angle) [rad / s] is obtained by differentiating the rotor phase α1 (electrical angle).

[0026] The motor rotation speed Nm [rpm] is calculated by dividing the rotor angular speed ω (electrical angle) by the number of pole pairs of the electric motor to obtain the motor rotation angular speed detection value ω m After calculating [rad / s], multiply it by the unit conversion factor (60 / 2π) from [rad / s] to [rpm] to calculate the value.

[0027] The DC voltage value Vdc [V] is obtained from a voltage sensor attached to the DC power supply line or from a power supply voltage value transmitted from a battery controller.

[0028] In the vibration suppression control calculation process in step S302, the vibration suppression control calculation of the present invention is performed. As will be described in detail later, in the vibration suppression control calculation of the present invention, the first torque command value Tm1 * (and total torque T mall * ) and the like, the first final torque command value T mf1 * Calculate.

[0029] In the current command value calculation process in step S303, the first final torque command value T mf1 * The first dq-axis current target value i is calculated from the motor rotation angular velocity detection value ωm and the DC voltage value Vdc. d1 * ,i q1 * is found by looking up the value in the table.

[0030] In the current control of step S304, first, the three-phase current value i of the first motor 8A is u1 ,i v1 ,i w1 and the first dq-axis current value i from the rotor phase α1 of the first motor 8A. d1 ,i q1 Calculate the following.

[0031] Next, the first dq-axis current target value i calculated in step S304 is d1 * ,i q1 * and the first dq-axis current value i d1 ,i q1 The first dq-axis voltage command value v d1 ,v q1 In addition, decoupling control may be added to this part.

[0032] Next, the first dq-axis voltage command value v d1 ,v q1 and the rotor phase α1 of the first motor 8A to the three-phase voltage command value v u1 ,v v1 ,v w1 This three-phase voltage command value v u1 , v v1 , v w1 and the DC voltage value Vdc to the first PWM signal (on duty) tu1 [%], t v1 [%], t w1 Calculates [%].

[0033] The first PWM signal thus obtained controls the opening and closing of the switching elements of the first inverter 3A, thereby driving the first motor 8A at the first final torque command value T mf1 * The motor can be driven at a desired torque indicated by the arrow.

[0034] The processing of the first motor controller 2A has been described above, but the second motor controller 2B also independently performs similar processing on the second motor 8B. That is, the second motor controller 2B controls the opening and closing of the switching elements of the second inverter 3AB using the second PWM signal calculated by the same processing as above, thereby controlling the second motor 8B to the second final torque command value T mf2 * The motor is driven at the desired torque indicated by the arrow.

[0035] [Vibration suppression control calculation overview] Fig. 4 is a block diagram showing an example of a functional configuration for executing vibration damping control processing in the control device for an electric vehicle of the first embodiment. As shown in Fig. 4, the control device for an electric vehicle of the first embodiment includes, as components (programs) that execute the vibration damping control processing, a rotational motion parameter calculator 21, an F / F compensator 22 (feedforward compensator), an F / B compensator 23 (feedback compensator), and an adder 24. Note that Fig. 4 shows the components implemented in the first motor controller 2A, but similar components are also implemented in the second motor controller 2B.

[0036] The rotational motion parameter calculator 21 calculates the total torque T mall *The rotational motion parameter calculator 21, which will be described in detail later, has a vehicle model that represents the response of the driving force transmission mechanism including the first motor 8A, the second motor 8B, the speed reducer 9, and the drive shaft 10, and assumes that the first motor 8A and the second motor 8B are an inertial body that rotates integrally. The rotational motion parameter calculator 21 then calculates the total torque T mall * When the vehicle model is input, a parameter related to the rotational motion of the driving force transmission mechanism, for example, a drive shaft torsional angular velocity estimate ω d ^, motor rotation angular velocity estimate ω m Calculate ^.

[0037] The F / F compensator 22, which will be described in detail later, calculates a first torque command value T m1 * , total torque T mall * , the estimated drive shaft torsional angular velocity ω d When ^ is input, the first torque command value T m1 * and total torque T mall * The first F / F torque command value T mff1 * Calculate.

[0038] The F / B compensator 23, which will be described in detail later, calculates the first torque command value T m1 * , total torque T mall * , motor rotation angular velocity estimate ω m ^, motor rotation angular velocity detection value ω m When is input, the first F / B torque command value T mfb1 * Calculate.

[0039] The adder 24 calculates the first F / F torque command value T mff1 * and the first feedback torque command value T mfb1 * The first final torque command value T mf1 * Output.

[0040] [Drive force transmission system model] Figure 5 is a diagram showing a model of the driving force transmission system of an electric vehicle. The equations of motion of the vehicle are expressed by equations (1) to (6).

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[0041]

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[0042]

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[0043]

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[0044]

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[0045]

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[0046] J m : Motor inertia J w : Drive shaft inertia (for one shaft) K d : Torsional rigidity of the drive shaft K f : Coefficient of friction between the drive wheels and the road surface N: Overall gear ratio r: tire load radius ω m : Motor rotation angular velocity θ m : Motor rotation angle ω w : Drive wheel rotation angular velocity θw : Drive wheel rotation angle T m :Motor torque T d : Drive shaft torque F:: Driving force (for 2 axes) V: Vehicle speed θ d : Drive shaft twist angle

[0047] In addition, J m is the motor inertia when the first motor 8A and the second motor 8B are regarded as an inertial body that rotates substantially as one unit in the driving force transmission system, and has the relationship of equation (7).

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[0048] J m1 : Inertia of the first motor 8A J m2 : Inertia of the second motor 8B Equations (1) to (6) are Laplace transformed to obtain the motor torque T m from the motor rotation angular velocity ω m The transfer characteristics up to this point are calculated as follows:

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[0049]

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[0050]

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[0051]

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[0052]

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[0053] From equations (2), (4), (5), and (6), the motor rotation angular velocity ω m from the drive shaft angular velocity ω w The transfer characteristics up to this point are calculated as follows:

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[0054] From equations (8), (9), and (14), the motor torque T m from the drive shaft angular velocity ω w The transfer characteristic is as follows:

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[0055] From equations (11) and (15), the drive shaft torque T d from the drive shaft angular velocity ω w The transfer characteristic is as follows:

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[0056] Now, transforming equation (1) gives:

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[0057] however,

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[0058]

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[0059]

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[0060]

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[0061]

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[0062] Also, equation (9) is

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[0063] Furthermore, when we examine the poles and zeros of equation (24), we find that α≒c0 / c1, so when the poles and zeros cancel out, we get the following equation.

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[0064] Here, the standard value of the vibration damping torque T mr * of

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[0065] where T m =T mr * By substituting equation (26) into equation (24), the following equation can be obtained:

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[0066] When the reference response from the motor torque to the drive shaft torque is expressed as follows:

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[0067]

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[0068] Next, equations (1) to (30) are applied to model the backlash characteristics from the motor to the drive shaft using a dead zone.

[0069] Drive shaft torque T d is expressed as follows instead of equation (4).

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[0070] Motor rotation angular velocity estimate ω m ^ is the integration of equation (1),

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[0071] Estimated drive shaft torsional angular velocity ω d ^ is the same as in equation (18),

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[0072] In the vibration control model 2113 (Fig. 6), the reference value of the vibration control torque T mr * Similarly to equation (26),

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[0073] [Rotational motion parameter calculator 21] 6 is a block diagram of the rotational motion parameter calculator 21. The rotational motion parameter calculator 21 includes a driving force transmission system model 2101 and a vibration damping model 2113 as vehicle models.

[0074] The driving force transmission system model 2101 includes a proportional element 2102 , a proportional element 2103 , a subtractor 2104 , an integral element 2105 , an integral element 2106 , a dead band element 2107 , a proportional element 2108 , a proportional element 2109 , a filter 2110 , a subtractor 2111 , and an integral element 2112 .

[0075] The vibration suppression model 2113 includes a subtractor 2114 and a proportional element 2115 .

[0076] The proportional element 2102 is a function of the output from the subtractor 2114 (the damping torque reference value T mr * ) is input, it is multiplied by a gain (1 / Jm) and output to a subtractor 2111.

[0077] The proportional element 2103 is a function of the output from the subtractor 2114 (the vibration damping torque reference value T mr * ) is input, the gain (1 / (Jm The result is multiplied by N) and output to the subtractor 2104.

[0078] Subtractor 2104 outputs the difference obtained by subtracting the output of filter 2110 from the output of proportional element 2103 to integral element 2105 .

[0079] The integral element 2105 integrates the output of the subtractor 2104 and outputs the result (the drive shaft torsional angular velocity estimate value ω d ^: Equation (33)) is output to the integral element 2106, the F / F compensator 22 (FIGS. 4 and 7), and the proportional element 2115.

[0080] The integral element 2106 is a function of the output of the integral element 2105 (the drive shaft torsional angular velocity estimate ω d ^) and integrate the output (θ d : Equation (31)) is output to the dead zone element 2107.

[0081] The deadband element 2107 is the output (θ d ) plus the backlash amount, and outputs the result to the proportional element 2108.

[0082] Proportional element 2108 applies a gain (K d : the torsional rigidity of the drive shaft 10) and its output (drive shaft torque T d : Equation (31) is input to a proportional element 2109 and a filter 2110.

[0083] Proportional element 2109 multiplies the output from proportional element 2108 by a gain (1 / (Jm·N)) and outputs the result to subtractor 2111 .

[0084] The filter 2110 applies a filter (H w (s): (19)) and output to the subtractor 2104.

[0085] Subtractor 2111 calculates the difference by subtracting the output of proportional element 2109 from the output of proportional element 2102 , and outputs the difference to integral element 2112 .

[0086] The integral element 2112 integrates the output from the subtractor 2111 and calculates the motor rotation angular velocity estimate ω m ^: Equation (32)) is output to the F / B compensator 23 (FIGS. 4 and 8).

[0087] The proportional element 2115 is a function of the output of the integral element 2105 (the estimated drive shaft torsional angular velocity ω d ^) torsional angular velocity gain k of the drive shaft all and outputs the result to the subtractor 2114.

[0088] The subtractor 2114 calculates the total torque T mall * The difference between the output of the proportional element 2115 and the output of the damping torque standard value T mr * : Equation (34)) is output to proportional element 2102 and proportional element 2103.

[0089] [F / F compensator 22] 7 is a block diagram of the F / F compensator 22. The F / F compensator 22 includes a drive shaft torsion angular velocity gain setting unit 221 and a subtractor 222.

[0090] The drive shaft torsion angular velocity gain setting unit 221 receives the first torque command value T m1 * , total torque T mall * , the estimated drive shaft torsional angular velocity ω d Then, the drive shaft torsional angular velocity gain setting unit 221 determines the first drive shaft torsional angular velocity gain k based on the following equation (36): ff1 and calculate the drive shaft torsional angular velocity estimate ω d ^1st drive shaft torsional angular velocity gain K ff1 The value obtained by multiplying the value by is output to the subtractor 222.

[0091] The subtractor 222 calculates the first torque command value T m1 * and the output of the drive shaft torsional angular velocity gain setting unit 221, the first F / F torque command value T mff1 *Calculate.

[0092] In equation (34), the estimated drive shaft torsional angular velocity ω generated by the combined torque of the first motor 8A and the second motor 8B is d ^ Drive shaft torsional angular velocity gain k all The reference response of equation (29) is realized by feeding back the value multiplied by the torque command value T. This pseudo feedback torque can be fed back to only one of the first motor 8A and the second motor 8B, or can be distributed to the first motor 8A and the second motor 8B. In the first embodiment, the torque distribution ratio between the first motor 8A and the second motor 8B (first torque command value T m1 * and the second torque command value T m2 * The feedback torque is distributed according to the ratio of the magnitude of

[0093] Therefore, the first F / F torque command value T mff1 * to the following equation

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[0094] [F / B compensator] 8 is a block diagram of the F / B compensator 23. The F / B compensator 23 includes an adder 231 , a subtractor 232 , a filter 233 , a filter 234 , and an F / B gain setting unit 235 .

[0095] The adder 231 calculates the motor rotation angular velocity estimate value ω m^ and the output of the filter 234 (the motor rotation angular velocity estimated value for the F / B torque command value), and the resulting output (the final motor rotation angular velocity estimated value ω mf ^) is output to the subtractor 232.

[0096] The subtractor 232 subtracts the output of the adder 231 (the final motor rotation angular velocity estimate value ω mf ^, or motor rotation angular velocity estimate ω m ^) to the motor rotation angular velocity detection value ω m The difference is calculated by subtracting the difference, and the difference is output to the filter 233.

[0097] The filter 233 applies a transfer characteristic (H(s) / G p (s)) and outputs the result to the filter 234 and the F / B gain setting unit 235.

[0098] The filter 234 applies a transfer characteristic (G p (s)) and outputs the output (motor rotation angular velocity estimate value for the F / B torque command value) to the adder 231.

[0099] The F / B gain setting unit 235 receives the first torque command value T m1 * , total torque T mall * , and the output of the filter 233 are input.

[0100] The F / B gain setting unit 235 sets the first F / B gain k fb1 is calculated as follows:

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[0101] The F / B gain setting unit 235 also sets the first F / B torque command value T mfb1 * is calculated as follows:

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[0102] As described above, the F / B compensator 23 calculates the motor rotation angular velocity estimated value ω m ^(or estimated final motor rotation angular velocity ω mf ^) and motor rotation angular velocity detection value ω m The deviation of the first F / B gain k is passed through a filter H(s) / Gp(s) (filter 233) consisting of the inverse characteristic of the transfer characteristic Gp(s) of the controlled object and a band-pass filter H(s). fb1 By multiplying this, the first F / B torque command value T mfb1 * Calculate.

[0103] Here, the transfer characteristic G p (s) is applied to equation (9). The bandpass filter H(s) is set so that the attenuation characteristics of the low-pass side and the high-pass side are approximately the same, and the torsional resonance frequency of the drive system is near the center of the passband on a logarithmic axis (log scale). For example, if H(s) is configured with a first-order high-pass filter and a first-order low-pass filter, the frequency f p is the torsional resonance frequency of the drive train, and k is an arbitrary value, and the equation is constructed as shown in equation (39).

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[0104] By the way, the actual motor rotation angular velocity detection value ω m The above-mentioned F / B compensation based on the above can be fed back to only one of the first motor 8A and the second motor 8B, or can be distributed to the first motor 8A and the second motor 8B simultaneously. In this embodiment, as described above, the F / B torque is distributed according to the torque distribution ratio between the first motor 8A and the second motor 8B.

[0105] The vibration suppression control calculation process executed by the first motor controller 2A has been described above, but the second motor controller 2B also executes the same process.

[0106] FIG. 9 shows the first drive shaft torsional angular velocity gain k assigned to the first motor controller 2A in the control device for an electric vehicle according to the first embodiment. ff1 and the first F / B gain k fb1 , and the second drive shaft torsional angular velocity gain k allocated to the second motor controller 2B ff2 and 2nd floor / Bk fb2 10 is a table showing gains.

[0107] As shown in FIG. 9, the first torque command value T m1 * and the second torque command value T m2 * The sum of these is the total torque T mall * In addition, the drive shaft torsional angular velocity gain for realizing a reference response (reducing drive shaft torsional vibration) in a vehicle model that represents the response of the drive force transmission mechanism including the first motor 8A, the second motor 8B, the reducer 9, and the drive shaft 10 and that assumes the first motor 8A and the second motor 8B as an inertial body that rotates integrally is defined as k all Furthermore, the F / B gain that satisfies a predetermined stability margin (gain margin, phase margin) of the F / B control system (step S304 in FIG. 3) of the control device for an electric vehicle according to this embodiment is set to k fball Let's say.

[0108] At this time, as described above, the first drive shaft torsional angular velocity gain k ff1 k ff1 =k all (T m1 * / T mall * ) and the first F / B gain k fb1 k fb1 =k fball (T m1 * / T mall * )

[0109] Also, the second drive shaft torsional angular velocity gain k applied to the second motor controller 2B ff2 k ff2 =k all (T m2 * / T mall * ) and set the second F / B gain k fb2 k fb2 =k fball (T m2 * / T mall * ), where k all =k ff1 +k ff2 , k fball =k fb1 +k fb2 is.

[0110] As is clear from FIG. 9, the first torque command value T m1 * and the second torque command value T m2 * If there is a difference between the two, the F / B gain will be variable depending on the distribution ratio, but the total amount of F / B torque when F / B control is performed by the first motor 8A and the second motor 8B will be constant regardless of the distribution ratio, so the stability margin will also be constant.

[0111] [Second embodiment] 10 is a diagram showing an example of the basic configuration of a control device for an electric vehicle according to the second embodiment. In the second embodiment, the outputs of the first motor 8A and the second motor 8B are the same, and the first torque command value T m1 * and the second torque command value T m2 * It is assumed that the magnitudes of

[0112] The vehicle controller 1 determines a first torque command value T to be instructed to the first motor controller 2A from the accelerator opening-torque table shown in FIG. 2 based on the vehicle speed V [km / h] obtained from the wheel rotation sensor 7 and the accelerator opening θ [%] obtained from the accelerator opening sensor (not shown). m1 * , a second torque command value T m2 * and outputs the first torque command value T m1 * and the second motor controller 2B is instructed to output the second torque command value T m2 * command.

[0113] The current control (FIG. 3) executed by the first motor controller 2A and the second motor controller 2B is the same as in the first embodiment.

[0114] 11 is a block diagram showing an example of a functional configuration for executing vibration damping control processing in a control device for an electric vehicle according to the second embodiment. The first motor controller 2A (and the second motor controller 2B) includes an F / F compensator 22, a rotational motion parameter calculator 21, an F / B compensator 23, and an adder 24 as components that also execute vibration damping control processing, similar to the first embodiment.

[0115] The F / F compensator 22 calculates the first torque command value T m1 * The first F / F torque command value T is calculated based on the following equation: mff1 * is calculated and output to the adder 24.

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[0116] The rotational motion parameter calculator 21 calculates the first F / F torque command value T mff1 When input, the motor rotation angular velocity estimate ω is calculated using the following equation based on equation (8). m Calculate ^.

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[0117] The F / B compensator 23 receives the motor rotation angular velocity estimate ω m ^ and motor rotation angular velocity detection value ω m is entered.

[0118] As in the first embodiment, the F / B compensator 23 calculates the motor rotation angular velocity estimated value ωm^ and the motor rotation angular velocity detected value ω m The deviation of the control target is taken and passed through a filter H(s) / Gp(s) consisting of the inverse characteristic of the transfer characteristic Gp(s) of the control target and a band-pass filter H(s) to generate a gain k fball / 2 to obtain the first F / B torque command value T mfb1 * Calculate the gain k fball is a value that satisfies the stability margin (gain margin, phase margin) of the F / B control system (step S304 in FIG. 3). Therefore, when setting the F / B gain in the first motor controller 2A and the second motor controller 2B, the F / B gain k fball You need to set half the value of each.

[0119] As in the first embodiment, the adder 24 calculates the first F / F torque command value T mff1 * and the first feedback torque command value T mfb1 * The first final torque command value T mf1 * Output.

[0120] [Third embodiment] FIG. 12 shows the first drive shaft torsional angular velocity gain k 1 allocated to the first motor controller 2A in the control device for an electric vehicle according to the third embodiment. ff1 and the first F / B gain k fb1 , and the second drive shaft torsional angular velocity gain k allocated to the second motor controller 2B ff2 and second F / B gain k fb2 1 is a table showing the above.

[0121] The control device for an electric vehicle of the third embodiment and the electric vehicle to which it is applied are similar to those of the first embodiment, but the drive shaft torsional angular velocity gain and F / B gain are allocated according to the ratio between the maximum output Pmax1 (maximum torque) of the first motor 8A and the maximum output Pmax2 (maximum torque) of the second motor 8B.

[0122] That is, the first torque command value T m1 * Regardless of ff1 k ff1 =k all (P max1 / (P max1 +P max2 )) and the first F / B gain k fb1 k fb1 =k fball (P max1 / (P max1 +P max2 )).

[0123] In addition, the second torque command value Tm2 * Regardless of ff2 k ff2 =k all (P max2 / (P max1 +P max2 )) and set the second F / B gain k fb2 k fb2 =k fball (P max2 / (P max1 +P max2 )).

[0124] By allocating the drive shaft torsional angular velocity gain and F / B gain as described above, the drive shaft torsional angular velocity gain and F / B gain can be set to fixed values, thereby reducing the calculation burden on the first motor controller 2A and the second motor controller 2B.

[0125] [Fourth embodiment] FIG. 13 shows the first drive shaft torsional angular velocity gain k assigned to the first motor controller 2A in the control device for an electric vehicle according to the fourth embodiment. ff1 and the first F / B gain k fb1 , and the second drive shaft torsional angular velocity gain k allocated to the second motor controller 2B ff2 and second F / B gain k fb2 1 is a table showing the above.

[0126] The control device for an electric vehicle of the fourth embodiment and the electric vehicle to which it is applied are similar to those of the first embodiment, but are applied to the case where, for example, motors with different rotation detection accuracies are used in combination.

[0127] When combining two types of electric motors, if there are differences in the type of rotation sensor used or in the detection method (actually measured value versus estimated value), using an electric motor with higher rotation detection accuracy will improve torque accuracy and make it easier to demonstrate performance, at least when using the motor rotation angular velocity detection value in feedback compensation. Therefore, for example, if the rotation detection accuracy of first motor 8A is higher than that of second motor 8B, the drive shaft torsional angular velocity gain and F / B gain applied to first motor controller 2A and second motor controller 2B are allocated as shown in Figure 13.

[0128] That is, the first torque command value T m1 * Regardless of ff1 k ff1 =k all and the first F / B gain k fb1 k fb1 =k fball Set to.

[0129] In addition, the second torque command value T m2 * Regardless of ff2 k ff2 = 0, and the second F / B gain k fb2 k fb2 Set =0.

[0130] [Time chart 1] FIG. 14 is a graph comparing the time charts for switching from negative torque to positive torque between the conventional technology and this embodiment in the control devices for electric vehicles of the first, third, and fourth embodiments, in which [A] is the total torque amount and torque command value, [B] is the drive shaft torsion angular velocity estimated value, [C] is the motor rotational angular velocity estimated value, [D] is F / F torque, [E] is the final torque command value, [F] is drive shaft torque, [G] is the motor rotational angular velocity detected value, and [H] is F / B torque.

[0131] FIG. 14 shows the response in a scene where the torque command value is changed in a stepwise manner from a state where regenerative torque is being generated and the vehicle is decelerating, and then the vehicle accelerates again.

[0132] A control device for an electric vehicle according to the prior art (see Patent Document 1) to which the present invention is compared is applied to an electric vehicle in which a pair of motors are attached to a reducer and the torque of the pair of motors can be transmitted to a drive shaft, and the drive shaft torsional angular velocity gain and F / B gain applied to one of the pair of motors (the same goes for the other motor) (controller) are set so that the drive force transmission system, which includes one motor, reducer, and drive shaft, has a standard response to a torque command value commanded to one motor (controller).

[0133] That is, in the prior art, the drive shaft torsional angular velocity gain is set to a value for calculating an F / F torque that offsets drive shaft torsional vibration related to the drive shaft torsional angular velocity estimated value when torque is input to only one motor (similar to the other), and the F / B gain is set to a value that satisfies a stability margin when F / B control is performed based on the difference between the estimated motor rotational angular velocity value and the detected motor rotational angular velocity value, and the drive shaft torsional angular velocity estimated value when torque is input to only one motor (similar to the other).

[0134] Therefore, in the prior art, when calculating the drive shaft torsion angular velocity estimate value and the motor rotational angular velocity estimate value, the case where two motors are driven simultaneously is not taken into consideration.

[0135] As shown in FIG. 14[A], at time t0, the torque command value (first torque command value T m1 * , second torque command value T m2 * ) changes stepwise. For simplicity, the first torque command value T m1 * = Second torque command value T m2 * = (Total torque T mall* ) / 2.

[0136] As shown in Figure 14[B], in the prior art (dashed line), the drive shaft torsional angular velocity estimate is calculated based on the torque of one motor, which deviates from the value calculated based on the torque of two motors. On the other hand, in the present invention (solid line), the drive shaft torsional angular velocity estimate is calculated based on the torque of two motors.

[0137] As shown in Fig. 14[C], in the present invention (solid line), the estimated motor rotational angular velocity is calculated based on the torque of two motors. Therefore, in the present invention, the estimated motor rotational angular velocity and the detected motor rotational angular velocity (solid line) shown in Fig. 14[G] almost coincide with each other, and almost no F / F torque is generated, as shown in Fig. 14[H].

[0138] On the other hand, as shown in Fig. 14[C], in the conventional technology (dashed line), the estimated motor rotational angular velocity is calculated based on the torque of one motor. Therefore, in the conventional technology, the estimated motor rotational angular velocity deviates significantly from the detected motor rotational angular velocity (solid line) shown in Fig. 14[G], and as shown in Fig. 14[H], unnecessary F / B torque oscillates in response to the drive shaft torsion angular velocity after time t0. Therefore, as shown in Fig. 14[G], the detected motor rotational angular velocity also oscillates.

[0139] As mentioned above, in the prior art, the set value of the F / B gain is set for each of the two motors to satisfy the stability margin when driven by one motor, resulting in excessive gain and causing oscillation. On the other hand, in the present invention, the sum of the F / B gains of the two motors (k fb1 +k fb2 ) is the gain (k fball ) so there is no vibration.

[0140] As shown in Figure 14[D], in the prior art (dashed line), the F / F torque is calculated based on the torque of one motor. On the other hand, in this embodiment (solid line), the F / F torque is calculated based on the torque of two motors. There is no difference between the prior art and the present invention regarding the F / F torque from time t0 to time t1.

[0141] In both cases, torque is applied to the two motors, and the dead zone for gear backlash is passed at time t1. However, in conventional technology, the F / F torque is calculated based on the torque of one motor, so the dead zone is determined to have been passed at time t2, which is delayed from time t1, and the F / F torque is increased. In contrast, in this embodiment, the F / F torque is calculated based on the torque of two motors, and the F / F torque is increased at the timing when the dead zone is actually passed.

[0142] The final torque command value (solid line) of the present invention shown in Figure 14[E] corresponds to the sum of the solid curve shown in Figure 14[D] and the solid curve shown in Figure 14[H]. Similarly, the final torque command value (dashed line) of the prior art shown in Figure 14[E] corresponds to the sum of the dashed curve shown in Figure 14[D] and the dashed curve shown in Figure 14[H]. Furthermore, the drive shaft torque (solid line, dashed line) in Figure 14[F] is calculated using the curves (solid line, dashed line) in Figure 14[E], equations (28), and (31).

[0143] As shown by the final torque command value (dashed line) in Figure 14[E] and the drive shaft torque (dashed line) in Figure 14[F], in the prior art, torque begins to rise after time t2, which is later than time t1 when the dead zone is crossed, causing a feeling of stagnation in acceleration. Furthermore, in the drive shaft torque (dashed line) in Figure 14[F], the vibration component appearing in the dashed curve in Figure 14[G] is offset by the vibration component appearing in the dashed curve in Figure 14[E]. However, the drive shaft torque (dashed line) still has a vibrational response, which can be uncomfortable for the driver. Furthermore, the torque reaches a steady value at approximately time t4.

[0144] On the other hand, as shown by the final torque command value (solid line) in Figure 14[E] and the drive shaft torque (solid line) in Figure 14[F], in the present invention, the torque starts to rise after time t1 when the dead zone is passed, significantly improving the feeling of sluggish acceleration. Furthermore, by accelerating the torque to a steady value earlier (from time t4 to time t3), the feeling of sluggish acceleration is also significantly reduced. Furthermore, the vibration response caused by excessive F / B gain is also improved, improving ride comfort. As a result, even when two motors are used, it is possible to accelerate again without causing discomfort to the driver.

[0145] [Time chart 2] FIG. 15 is a graph comparing the time charts when switching from positive torque (small) to positive torque (large) in the control device for an electric vehicle of the second embodiment between the conventional technology and this embodiment, where [A] is the total torque amount and torque command value, [B] is the motor rotational angular velocity estimated value, [C] is the F / B torque, [D] is the drive shaft torque, and [G] is the motor rotational angular velocity detected value.

[0146] Here we see the response when power torque is generated and the accelerator is pressed during gentle acceleration.

[0147] As shown in FIG. 15[A], at time t0, the torque command value and the total torque amount change stepwise.

[0148] As shown in Fig. 15[B], in the prior art (dashed line), the motor rotational angular velocity estimate is calculated based on the torque of one motor, which deviates from the motor rotational angular velocity detection value (solid line) shown in Fig. 15[E]. Therefore, as shown by the dashed curve in Fig. 15[C], unnecessary F / B torque is generated after time t0.

[0149] On the other hand, in the present invention (solid line), the estimated motor rotational angular velocity is calculated based on a torque twice that of one motor, which is almost the same as the detected motor rotational angular velocity value (solid line) shown in Fig. 15[E]. Therefore, as shown by the solid curve in Fig. 15[C], almost no unnecessary F / B torque is generated even after time t0.

[0150] Therefore, as shown in Figure 15[D], the time when the drive shaft torque reaches a steady value is delayed until t2 in the prior art, but is accelerated to t1 in the present invention, significantly reducing the sluggish feeling during acceleration. As a result, even when two motors are used, acceleration is possible without causing discomfort to the driver.

[0151] [Effects of this embodiment] According to the control method for an electric vehicle of this embodiment, a driving force transmission mechanism (reduction gear 9, drive shaft 10) is provided that combines the power of multiple electric motors (first motor 8A, second motor 8B) on one drive shaft 10 and transmits the power to drive wheels 11A, 11B, and a torque command value (first torque command value T m1 * , second torque command value T m2 * ) and set the torque command value (first torque command value T m1 * , second torque command value T m2 * ) is a control method for an electric vehicle that controls the torque of electric motors (first motor 8A, second motor 8B) by a vehicle model (G p (s)) to the torque command value (first torque command value T m1 * , second torque command value T m2 * ) is the total torque T mall * Enter the vehicle model (G p (s)) parameter correlated with the rotational motion (drive shaft torsional angular velocity estimate ω d ^, motor rotation angular velocity estimate ω m ^) and calculate the total torque T so that the rotational motion becomes the standard response. mall * The parameter (drive shaft torsional angular velocity estimate ω d^, motor rotation angular velocity estimate ω m ^) to a given gain (k all , k fball ) and the correction amount (k fall ω d ^, k fball (H(s) / G p (s)(ω m ^-ω m ))) when correcting based on the gain (k all , k fball The distribution gain ((k ff1 ,k ff2 ), (k fb1 ,k fb2 )) are set individually to the electric motors (first motor 8A, second motor 8B), and the parameter (drive shaft torsion angular velocity estimated value ω d ^, motor rotation angular velocity estimate ω m ^) to the distribution gain ((k ff1 ,k ff2 ), (k fb1 ,k fb2 )) is multiplied by the distribution correction amount (first F / F torque command value T mff1 * , the first F / B torque command value T mfb1 * , the second F / F torque command value T mff2 * , the second F / B torque command value T mfb2 * ) based on the torque command value (first torque command value T m1 * , second torque command value T m2 * ) are corrected individually.

[0152] The above method allows a vehicle equipped with a driving force transmission mechanism (reduction gear 9, drive shaft 10) that combines the power of multiple electric motors (first motor 8A, second motor 8B) on the drive shaft 10 to simulate a single inertial body that is rigidly connected and rotates substantially as one unit. This allows vibration damping control to be performed using controllers (first motor controller 2A, second motor controller 2B) that individually control the electric motors (first motor 8A, second motor 8B), just as in the case of a single electric motor for the drive shaft 10. In this case, parameters correlated with the rotational motion of the driving force transmission system (e.g., motor rotation speed, motor angular acceleration, drive shaft torsional angular velocity, drive shaft torque, etc.) are calculated based on the total torque generated by the multiple electric motors, rather than the torque of each individual electric motor. This allows the parameters to be calculated accurately, preventing the torque generated by each electric motor from acting as a disturbance, and effectively suppressing vibrations occurring in the vehicle (particularly torsional vibration of the drive shaft 10).

[0153] In the above control method, the parameter (drive shaft torsion angular velocity estimated value ω d ^, motor rotation angular velocity estimate ω m ^) is the estimated rotational angular velocity of the electric motor (first motor 8A, second motor 8B) (the estimated motor rotational angular velocity ω m ^), and the gain (k all , k fball ) is the estimated rotational angular velocity (the estimated motor rotational angular velocity ω m ^) and the rotational angular velocity detection value of the electric motor (first motor 8A, second motor 8B) (motor rotational angular velocity detection value ω m ) is multiplied by the difference between the feedback gain (k fbll ) and the feedback gain (k fbll ) and the difference, so as to reduce the difference. mall * In the case of correcting the distribution gain, the feedback gain (k fbll ) is the sum of the distributed feedback gain (k fb1 , f fb2 ) and the difference is the distributed feedback gain (k fb1 , ffb2 ) is multiplied by the distribution correction amount (first F / B torque command value T mfb1 * , the second F / B torque command value T mfb2 * ) based on the torque command value (first torque command value T m1 * , second torque command value T m2 * ) are corrected individually.

[0154] If the same feedback compensation as when the drive shaft 10 is driven by one electric motor is performed using multiple electric motors using the above method, overcompensation may occur and the necessary stability margin may not be ensured. Therefore, by individually setting the feedback gains of the multiple electric motors so that the necessary stability margin is ensured, feedback compensation can be performed without compromising stability.

[0155] In the above control method, the distribution feedback gain (k fb1 , f fb2 ) to the maximum output (P max1 , P max2 ) is higher, the higher the setting.

[0156] Using the above method, when electric motors with different maximum outputs are used in combination, the electric motor with the higher maximum output can perform a large amount of torque compensation. Therefore, by setting a large F / B gain for the electric motor with the higher maximum output, it is possible to perform the necessary F / B compensation while avoiding torque shortages in the electric motor with a small range of torque compensation possible.

[0157] In addition, in the above control method, the distribution feedback gain (k fb1 , f fb2 ) to the total torque T mall * Torque command value (first torque command value T m1 * , second torque command value T m2 * ) ratio. This allows you to easily set the distributed F / B gain (k fb1 , ffb2 ) can be set.

[0158] In the above control method, the distribution feedback gain (k fb1 , f fb2 ) is converted into the rotational speed detection value (motor rotational angular velocity detection value ω m The higher the detection accuracy of , the higher the setting.

[0159] By using the above method, when electric motors with different performance of angle detectors such as resolvers (or electric motors with and without angle detectors) are used in combination, it is possible to obtain a higher rotation speed (motor rotation angular velocity detection value ω m ) detection accuracy, the rotation speed (motor rotation angular velocity detection value ω m ) can improve the accuracy of F / B compensation based on

[0160] In the above control method, the parameter (drive shaft torsion angular velocity estimated value ω d ^, motor rotation angular velocity estimate ω m ^) is the estimated torsional angular velocity of the drive shaft 10 (the estimated torsional angular velocity of the drive shaft ω d ^) and gain (k all , k fball ) is the estimated torsional angular velocity (the estimated drive shaft torsional angular velocity ω d Drive shaft torsional angular velocity gain k multiplied by all and a drive shaft torsional angular velocity gain k all and the estimated torsional angular velocity (the estimated drive shaft torsional angular velocity ω d The total torque T is calculated based on the product of mall * When correcting the distribution gain, the drive shaft torsional angular velocity gain k all The distribution drive shaft torsional angular velocity gain (first drive shaft torsional angular velocity gain k ff1 , second drive shaft torsional angular velocity gain k ff2 ), and the torsional angular velocity estimate (drive shaft torsional angular velocity estimate ω d^) to the distribution drive shaft torsional angular velocity gain (first drive shaft torsional angular velocity gain k ff1 , second drive shaft torsional angular velocity gain k ff2 ) is multiplied by the distribution correction amount (first F / F torque command value T mff1 * , the second F / F torque command value T mff2 * ) based on the torque command value (first torque command value T m1 * , second torque command value T m2 * ) are corrected individually.

[0161] The above method makes it possible to accurately simulate nonlinear responses including dead zones such as gear backlash, and to perform F / F compensation appropriately.

[0162] In the above control method, the distribution feedforward gain (k ff1 , k ff2 ) to the total torque T mall * Torque command value (first torque command value T m1 * , second torque command value T m2 * ) ratio. This allows the distribution drive shaft torsional angular velocity gain (k ff1 , f ff2 ) can be set.

[0163] Furthermore, according to the control device for an electric vehicle of the present invention, the control device for an electric vehicle includes a plurality of electric motors (first motor 8A, second motor 8B) and a driving force transmission mechanism (reduction gear 9, drive shaft 10) that combines the power of the plurality of electric motors (first motor 8A, second motor 8B) on one drive shaft 10 and transmits the power to drive wheels 11A, 11B, and the control device calculates a torque command value (first torque command value T) for the electric motors (first motor 8A, second motor 8B) based on vehicle information (vehicle speed V, accelerator opening θ). m1 * , second torque command value T m2 * ) and a vehicle controller 1 that sets a torque command value (first torque command value Tm1 * , second torque command value T m2 * The vehicle is provided with a plurality of motor controllers (first motor controller 2A, second motor controller 2B) that individually control the torque of the electric motors (first motor 8A, second motor 8B) by a drive force transmission mechanism (reduction gear 9, drive shaft 10). The motor controllers (first motor controller 2A, second motor controller 2B) are based on a vehicle model (G p (s)) to the torque command value (first torque command value T m1 * , second torque command value T m2 * ) is the total torque T mall * Enter the vehicle model (G p (s)) parameter correlated with the rotational motion (drive shaft torsional angular velocity estimate ω d ^, motor rotation angular velocity estimate ω m ^), and a parameter calculation means (rotational motion parameter calculator 21) for calculating the total torque T mall * The parameter (drive shaft torsional angular velocity estimate ω d ^, motor rotation angular velocity estimate ω m The correction amount (k fall ω d ^, k fball (H(s) / G p (s)(ω m ^-ω m ))) when correcting based on the gain (k all , k fball The distribution gain ((k ff1 ,k ff2 ), (k fb1 ,k fb2 )) are set individually to the electric motors (first motor 8A, second motor 8B), and the parameter (drive shaft torsion angular velocity estimated value ω d ^, motor rotation angular velocity estimate ω m ^) to the distribution gain ((k ff1 ,kff2 ), (k fb1 ,k fb2 )) is multiplied by the distribution correction amount (first F / F torque command value T mff1 * , the first F / B torque command value T mfb1 * , the second F / F torque command value T mff2 * , the second F / B torque command value T mfb2 * ) based on the torque command value (first torque command value T m1 * , second torque command value T m2 * and torque command value correcting means (F / F compensator 22, F / B compensator 23) for individually correcting the torque command values.

[0164] With the above configuration, even in a vehicle equipped with a driving force transmission mechanism (reduction gear 9, drive shaft 10) that combines the power of multiple electric motors (first motor 8A, second motor 8B) on the drive shaft 10, simulating an electric motor of a single inertial body that is rigidly connected and rotates substantially as one unit enables vibration suppression control using controllers (first motor controller 2A, second motor controller 2B) that individually control the electric motors (first motor 8A, second motor 8B), just as in the case of a single electric motor for the drive shaft 10. In this case, parameters correlated with the rotational motion of the driving force transmission system (e.g., motor rotation speed, motor angular acceleration, drive shaft torsional angular velocity, drive shaft torque, etc.) are calculated based on the total torque generated by the multiple electric motors, rather than the torque of each individual electric motor. This enables accurate calculation of the parameters, preventing the torque generated by each electric motor from acting as a disturbance, and effectively suppressing vibrations occurring in the vehicle (particularly torsional vibration of the drive shaft 10).

[0165] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and the technical scope of the present invention is not intended to be limited to the specific configurations of the above embodiments. Furthermore, the above embodiments can be combined as appropriate. [Explanation of symbols]

[0166] 1 vehicle controller, 2A first motor controller, 2B second motor controller, 8A first motor, 8B second motor, 9 reducer, 10 drive shaft, 11A drive wheel, 11B drive wheel, rotational motion parameter calculator 21, 22 F / F compensator, 23 F / B compensator

Claims

1. A control method for an electric vehicle including a driving force transmission mechanism that combines power from a plurality of electric motors on one drive shaft and transmits the combined power to drive wheels, setting a torque command value for the electric motor based on vehicle information, and controlling torque of the electric motor based on the torque command value, a total torque amount, which is the sum of the torque command values, is input to a vehicle model that models the characteristics of the plurality of electric motors in the driving force transmission mechanism when they are assumed to be inertial bodies that rotate together, and a parameter correlated with the rotational motion of the vehicle model is calculated; When the total torque amount is corrected based on a correction amount obtained by multiplying the parameter by a predetermined gain so that the rotational motion becomes a reference response, A distribution gain, which is the sum of the gains, is set individually for each of the electric motors; a control method for an electric vehicle, the torque command value being individually corrected based on a distribution correction amount obtained by multiplying the parameter by the distribution gain;

2. the parameters include an estimated rotational angular velocity of the electric motor; the gain includes a feedback gain that is multiplied by a difference between the rotational angular velocity estimation value and the rotational angular velocity detection value of the electric motor, When the total torque amount is corrected based on the product of the feedback gain and the difference so as to reduce the difference, the distributed gain includes a distributed feedback gain that is a sum of the feedback gains, 2. The method for controlling an electric vehicle according to claim 1, wherein the torque command values ​​are individually corrected based on the distribution correction amount obtained by multiplying the difference by the distribution feedback gain.

3. The method for controlling an electric vehicle according to claim 2, wherein the distribution feedback gain is set higher as the maximum output of the electric motor increases.

4. The method for controlling an electric vehicle according to claim 2 , wherein the distribution feedback gain is set based on a ratio of the torque command value to the total torque amount.

5. The method for controlling an electric vehicle according to claim 2, wherein the distribution feedback gain is set higher as the detection accuracy of the rotational speed detection value of the electric motor increases.

6. the parameters further include an estimated torsional angular velocity of the drive shaft; the gain further includes a drive shaft torsional angular velocity gain by which the torsional angular velocity estimate value is multiplied; In a case where the total torque amount is corrected based on the product of the drive shaft torsional angular velocity gain and the torsional angular velocity estimation value so as to reduce torsional vibration of the drive shaft, the distribution gain includes a distribution drive shaft torsional angular velocity gain that is a sum of the drive shaft torsional angular velocity gains, 6. The method for controlling an electric vehicle according to claim 2, wherein the torque command values ​​are individually corrected based on the distribution correction amount obtained by multiplying the torsional angular velocity estimate value by the distribution drive shaft torsional angular velocity gain.

7. The method for controlling an electric vehicle according to claim 6, wherein the distribution drive shaft torsional angular velocity gain is set based on a ratio of the torque command value to the total torque amount.

8. A control device for an electric vehicle including a plurality of electric motors and a driving force transmission mechanism that combines power of the plurality of electric motors on one drive shaft and transmits the power to a drive wheel, a vehicle controller that sets a torque command value for the electric motor based on vehicle information; a plurality of motor controllers that individually control the torque of the electric motors according to the torque command values; The motor controller a parameter calculation means for calculating a parameter correlated with rotational motion of a vehicle model obtained by inputting a total torque amount, which is the sum of the torque command values, into the vehicle model, which models the characteristics of the plurality of electric motors in the driving force transmission mechanism when they are assumed to be an inertial body rotating as a unit; a torque command value correcting means for individually setting a distribution gain, which is a sum of the gains, for the electric motors, and individually correcting the torque command value based on a distribution correction amount obtained by multiplying the parameter by the distribution gain, when correcting the total torque amount based on a correction amount obtained by multiplying the parameter by a predetermined gain so that the rotational motion becomes a reference response.

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