JP2017046419A - Control method of electric vehicle and control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform suitable drive shaft torque control corresponding to a vehicle status even if a disturbance caused by the intervention of a friction brake occurs when passing a gear-back rush.SOLUTION: A torque command value is set according to vehicle information, a dead zone in which motor torque is not transmitted to a drive shaft of a vehicle is compensated, a torque target value is calculated by applying filtering processing for reducing a natural vibration frequency component of a drive force transmission system of the vehicle to the torque command value, and the torque of a motor is controlled on the basis of the torque target value. Then, a compensation amount to the dead zone which is considered in the filtering processing is adjusted according to a friction brake amount for imparting a brake force to the vehicle.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electric vehicle control method and a control device.

  Conventionally, a linear filter that reduces the natural vibration frequency component in the vehicle torque transmission system, taking into account the dead band characteristics due to gear backlash, a filter that calculates the drive shaft torsion angle, and the calculated drive shaft torsion angle By calculating the motor torque command value by feed-forward calculation using a saturation function that gives the upper and lower limit values to the wheel, a wheel inertia of the drive shaft torsion angle, and a filter that compensates for phase shift due to tire friction force, the vehicle 2. Description of the Related Art A control device for an electric vehicle that suppresses torsional vibration generated on the drive shaft is known (see Patent Document 1).

JP 2013-223373 A

  By the way, when an actual vehicle travels, a disturbance due to friction brake intervention or the like occurs. When the braking force resulting from such disturbance acts on the drive shaft of the vehicle, the relative positional relationship between the gear on the motor shaft side and the gear on the drive shaft side is affected. In particular, in a scene in which the rotation of the drive shaft passes through the gear backlash section, a behavioral difference between the behavior of the gear when no disturbance occurs and the behavior of the gear when the disturbance occurs significantly appears.

  However, the electric vehicle control device described in Patent Document 1 does not consider disturbance due to the action of a friction brake or the like. For this reason, if the braking force due to the intervention of the friction brake acts on the drive shaft when passing through the gear backlash, the motor torque calculated in the state of misrecognizing the relative positional relationship between the motor shaft side gear and the drive shaft side gear. Since the drive shaft torque is controlled based on the command value, the drive shaft torsional vibration cannot be effectively suppressed.

  The present invention realizes appropriate drive shaft torque control according to vehicle conditions and effectively suppresses drive shaft torsional vibration even when disturbance due to friction brake occurs when passing through the gear backlash. Objective.

  The electric vehicle control method according to the present invention sets a torque command value based on vehicle information, compensates for a dead zone in which motor torque is not transmitted to the drive shaft of the vehicle, and reduces the natural vibration frequency component of the drive force transmission system of the vehicle. A torque target value is calculated by applying a filtering process to the torque command value, and the torque of the motor is controlled based on the torque target value. Then, the compensation amount for the dead zone considered in the filtering process is adjusted according to the friction brake braking amount that applies a braking force to the vehicle.

  According to the present invention, by adjusting the compensation amount for the dead zone considered in the filtering process according to the friction brake braking amount, it is possible to perform appropriate drive shaft torque control according to the vehicle situation. Thus, even when a disturbance due to the intervention of the friction brake occurs when passing through the gear backlash, it is possible to suppress the deterioration of the torque controllability and effectively suppress the drive shaft torsional vibration.

FIG. 1 is a block diagram illustrating a main configuration of an electric vehicle including the control device according to the first embodiment. FIG. 2 is a flowchart showing a flow of processing performed by the electric motor controller. FIG. 3 is a diagram illustrating an example of an accelerator opening-torque table. FIG. 4 is an example of a control block diagram for performing vibration damping control calculation processing for setting the final torque target value Tm2 ^* based on the target torque command value Tm1 ^* . FIG. 5 is a diagram modeling a vehicle driving force transmission system. FIG. 6 is an example of a block diagram of the vibration suppression control FF calculation unit. FIG. 7 is an example of a block diagram of the vibration suppression control FF calculation unit. FIG. 8 is an example of a block diagram of the vibration suppression control FB calculation unit. FIG. 9 is an example of a block diagram of the vibration suppression control FB calculation unit. FIG. 10 is a diagram illustrating the characteristics of the transfer function H (s). FIG. 11 is a flowchart showing a flow of processing executed by the electric motor controller. FIG. 12 is a flowchart showing a process related to a gear backlash compensation amount adjustment permission determination value. FIG. 13 is a flowchart showing a process related to a gear backlash compensation amount adjustment non-permission determination value. FIG. 14 is a flowchart showing processing for setting the value of the gear backlash amount θ _BL according to the first embodiment. FIG. 15 is a graph showing the relationship between the friction brake braking amount and the gear backlash amount to be compensated for in the driving force transmission system of the vehicle model. FIG. 16 is a time chart showing an example of a control result when the control device of the first embodiment is applied to an electric vehicle and a control result according to a conventional example. FIG. 17 is a flowchart showing processing for setting the value of the gear backlash amount θ _BL according to the second embodiment.

-First embodiment-
FIG. 1 is a block diagram illustrating a main configuration of an electric vehicle including the control device according to the first embodiment. The electric vehicle is an automobile that includes an electric motor as a part or all of the drive source of the vehicle and can run by the driving force of the electric motor, and includes an electric car and a hybrid car.

  The electric motor controller 2 is input with signals indicating the vehicle state such as the vehicle speed V, the accelerator opening θ, the rotor phase α of the electric motor 4, the currents iu, iv, and iw of the electric motor 4 as digital signals. The electric motor controller 2 generates a PWM signal for controlling the electric motor 4 based on the input signal. Further, a drive signal for the inverter 3 is generated according to the generated PWM signal.

  The inverter 3 converts the direct current supplied from the battery 1 into alternating current by turning on / off two switching elements (for example, power semiconductor elements such as IGBT and MOS-FET) provided for each phase. Then, a desired current is passed through the electric motor 4.

  The electric motor (three-phase AC motor) 4 generates a driving force by the AC current supplied from the inverter 3, and transmits the driving force to the left and right driving wheels 9 a and 9 b via the speed reducer 5 and the driving shaft 8. . The electric motor 4 collects the kinetic energy of the vehicle as electric energy by generating a regenerative driving force when the electric motor 4 rotates with the drive wheels 9a and 9b and rotates when the vehicle is traveling. In this case, the inverter 3 converts an alternating current generated during the regenerative operation of the electric motor 4 into a direct current and supplies the direct current to the battery 1.

  The current sensor 7 detects three-phase alternating currents iu, iv, iw flowing through the electric motor 4. However, since the sum of the three-phase alternating currents iu, iv, and iw is 0, any two-phase current may be detected, and the remaining one-phase current may be obtained by calculation.

  The rotation sensor 6 is, for example, a resolver or an encoder, and detects the rotor phase α of the electric motor 4.

  The brake controller 11 sets a friction brake braking amount command value according to the operation amount (depression amount) of the brake pedal 13, and controls the brake fluid pressure according to the friction brake braking amount command value. Further, the brake controller 11 outputs a friction brake braking amount command value to the electric motor controller 2 for use in a friction brake braking amount calculation process described later.

The friction brake 10 raises the brake fluid pressure according to the brake braking amount _Fdb input from the brake controller 11, thereby pressing the brake pad against the rotor and generating a braking force on the drive wheels 9a, 9b. The brake braking amount F _db will be described later.

  FIG. 2 is a flowchart showing a flow of processing performed by the electric motor controller 2. The processing from step S201 to step S206 is always executed at regular intervals while the vehicle system is activated.

In step S <b> 201, a signal indicating the vehicle state is input to the electric motor controller 2. Here, the vehicle speed V (km / h), the accelerator opening θ (%), the rotor phase α (rad) of the electric motor 4, the rotational speed Nm (rpm) of the electric motor 4, and the three-phase AC flowing through the electric motor 4 Current iu, iv, iw, DC voltage value Vdc (V) of battery 1, driven wheel friction brake command value F _bf ^* , driving wheel friction brake command value F _bd ^* , driving shaft torque T _dsft , and vehicle longitudinal acceleration detection The value a _s is entered.

  The vehicle speed V (km / h) is acquired by communication from a vehicle speed sensor (not shown) or another controller. Alternatively, the electric motor controller 2 obtains the vehicle speed v (m / s) by multiplying the rotor mechanical angular velocity ωm by the tire moving radius r and dividing by the gear ratio of the final gear, and multiplies by 3600/1000. Unit conversion is performed to determine the vehicle speed V (km / h).

  The electric motor controller 2 acquires the accelerator opening θ (%) from an accelerator opening sensor (not shown). The accelerator opening degree θ (%) may be acquired from another controller such as a vehicle controller (not shown).

  The rotor phase α (rad) of the electric motor 4 is acquired from the rotation sensor 6. The rotational speed Nm (rpm) of the electric motor 4 is obtained by dividing the rotor angular speed ω (electrical angle) by the pole pair number p of the electric motor, and the motor rotational speed ωm (rad / s) that is the mechanical angular speed of the electric motor 4. ) And the obtained motor rotation speed ωm is multiplied by 60 / (2π). The rotor angular velocity ω is obtained by differentiating the rotor phase α.

  Currents iu, iv, iw (A) flowing through the electric motor 4 are acquired from the current sensor 7.

The DC current value V _dc (V) is detected by a voltage sensor (not shown) provided on the DC power supply line between the battery 1 and the inverter 3. The DC voltage value V _dc (V) may be detected by a signal transmitted from a battery controller (not shown).

The driven wheel friction brake command value F _bf ^* and the drive wheel friction brake command value F _bd ^* are acquired from the brake controller 11. The friction brake braking amount command value shown in FIG. 1 is a comprehensive description of these.

The drive shaft torque T _dsft is a value calculated by another controller (not shown) based on the vehicle state, and is acquired from the controller by communication or the like.

The vehicle longitudinal acceleration detection value a _s is acquired from the G sensor 12 that detects the vehicle longitudinal acceleration. The sign of the vehicle longitudinal acceleration detection value a _s is determined so that the value when the vehicle is accelerating on a flat road is positive.

In step S202, the electric motor controller 2 sets a target torque command value Tm1 ^* as a basic target torque. Specifically, the electric motor controller 2 refers to the accelerator opening-torque table shown in FIG. 3 on the basis of the accelerator opening θ and the vehicle speed V input in step S201, and thereby the target torque command value Tm1 ^*. Set.

In step S203, the electric motor controller 2 determines the driven wheel brake braking amount F _dbf and the drive wheel based on the driven wheel friction brake command value F _bf ^* , the drive wheel friction brake command value F _bd ^* , and the vehicle speed V. The brake braking amount F _dbd is calculated. The electric motor controller 2 adds the driven wheel brake braking amount F _dbf and the driving wheel brake braking amount F _dbd to calculate the total brake braking amount F _db .

Specifically, the driven wheel brake braking amount F _dbf is calculated using the following equation (1), and the driving wheel brake braking amount F _dbd is calculated using the following equation (2). The total brake braking amount _Fdb is calculated by the following equation (3).

The transfer function G _b (s) used in the above equations (1) and (2) is as shown in the following equation (4).

Each parameter in said formula (1)-(4) is as showing below.
τ _b : brake response delay time constant L _b : brake response delay dead time F _bf ^* : driven wheel friction brake command value (indicating the absolute value of the braking amount for two wheels)
F _bd ^* : Driving wheel friction brake command value (indicating the absolute value of the braking amount for two wheels)
F _dbf : Driven wheel brake braking amount (for 2 wheels)
F _dbd : Driving wheel brake braking amount (for two wheels)
F _db : Total brake braking amount (for 4 wheels)
V: Vehicle speed The values of the driven wheel brake braking amount F _dbf , the driving wheel brake braking amount F _dbd , and the total brake braking amount F _db are determined by a hydraulic pressure sensor (not shown) that detects the brake hydraulic pressure, A detection value of the stroke sensor 13a or the like that detects the brake operation amount may be used. In the following description, these values related to the brake braking amount are collectively referred to as a friction brake braking amount.

In step S204, the electric motor controller 2 performs vibration suppression control calculation processing. Specifically, the electric motor controller 2 drives the driving force transmission system vibration (without driving shaft torque waste based on the target torque command value Tm1 ^* set in step S202 and the motor rotation speed ωm. A final torque target value Tm2 ^* after damping control that suppresses torsional vibration of the drive shaft 8) is calculated. Details of the vibration suppression control calculation process will be described later.

In step S205, the electric motor controller 2 performs a current command value calculation process. Specifically, the electric motor controller 2 determines the d-axis current target value id ^* and the q-axis based on the motor rotation speed ωm and the DC voltage value V _dc in addition to the final torque target value Tm2 ^* calculated in step S204. The current target value iq ^* is obtained. For example, by preparing in advance a table that defines the relationship between the torque command value, motor rotation speed, DC voltage value, d-axis current target value, and q-axis current target value, and referring to this table D-axis current target value id ^* and q-axis current target value iq ^* are obtained.

In step S206, current control is performed to match the d-axis current id and the q-axis current iq with the d-axis current target value id ^* and the q-axis current target value iq ^* obtained in step S205, respectively. For this reason, first, the d-axis current id and the q-axis current iq are obtained based on the three-phase alternating current values iu, iv, iw input in step S201 and the rotor phase α of the electric motor 4. Subsequently, d-axis and q-axis voltage command values vd and vq are calculated from a deviation between the d-axis and q-axis current command values id ^* and iq ^* and the d-axis and q-axis current id and iq. Here, non-interference control may be applied to the calculated d-axis and q-axis voltage command values vd and vq.

Next, three-phase AC voltage command values vu, vv, vw are obtained from the d-axis and q-axis voltage command values vd, vq and the rotor phase α of the electric motor 4. Then, PWM signals tu (%), tv (%), and tw (%) are obtained from the obtained three-phase AC voltage command values vu, vv, and vw and the current voltage value Vdc. The electric motor 4 can be driven with a desired torque indicated by the target torque command value Tm ^* by opening and closing the switching element of the inverter 3 by the PWM signals tu, tv, and tw thus obtained.

<Damping control calculation processing>
Below, the detail of the vibration suppression control calculation process performed in above-mentioned step S204 is demonstrated. The vibration suppression control calculation process is a process executed for the purpose of reducing a natural vibration frequency component in a driving force transmission system of a vehicle having a dead zone due to a delay due to wheel characteristics or a gear backlash.

FIG. 4 is an example of a control block diagram for setting the final torque target value Tm2 ^* by performing the vibration suppression control process on the target torque command value Tm1 ^* in the control apparatus for the electric vehicle according to the present embodiment. The vibration suppression control calculation unit 400 that sets the final torque target value Tm2 ^* includes a vibration suppression control feedforward calculation unit 401 (hereinafter referred to as a vibration suppression control FF calculation unit 401) and a vibration suppression control feedback calculation unit 402 (hereinafter referred to as a vibration suppression control feedback calculation unit 401). A vibration suppression control FB calculation unit 402) and a control backlash amount calculation unit 403.

The control backlash amount calculation unit 403 is a configuration characteristic of the present invention. In the vibration suppression control calculation process executed by the vibration suppression control calculation unit 400, the compensation amount for the dead zone of the driving force transmission system is determined by the friction brake. Adjust according to the amount of braking. Here, the compensation amount is determined according to the value of the overall gear backlash amount θ _BL from the motor 4 to the drive shaft 8 used for a saturation function St described later.

Therefore, the control backlash amount calculation unit 403 calculates the value of θ _BL suitable for the vehicle state according to the friction brake braking amount, and uses the calculated values as the vibration suppression control FF calculation unit 401 and the vibration suppression control FB calculation unit. By substituting into the saturation function of 402, the compensation amount for the dead zone of the driving force transmission system is adjusted.

Then, the first torque target value FF _out output from the vibration suppression control FF calculation unit 401 adjusted to an appropriate compensation amount and the second torque target output from the vibration suppression control FB calculation unit 402 adjusted similarly. ^* final torque target value Tm2 is calculated and the value FB _out is summed been to. By controlling the torque based on this final torque target value Tm2 ^* , it is possible to realize appropriate drive shaft torque control even if a disturbance related to brake braking occurs when the gear backlash section elapses. Details of the control backlash amount calculation unit 403 will be described later.

A feedforward calculation process performed by the vibration suppression control FF calculation unit 401 will be described. FIG. 5 is a diagram modeling a driving force transmission system of a vehicle, and each parameter in the figure is as shown below.
Jm: Motor inertia Jw: Drive wheel inertia (for one axis)
Kd: torsional rigidity Kt of the drive shaft: tires and a coefficient N _al Friction road: overall gear ratio r: tire load radius .omega.m: motor angular velocity Omegadaburyu: driving wheel velocity Tm: motor torque Td: drive wheel torque F: driving force ( (For two axes)
V: Vehicle speed θ: Torsion angle of drive shaft When the dead zone due to backlash is expressed by the difference between the linear function and the saturation function, the following equations of motion (5) to (10) can be derived from FIG.

  However, St (θ) in the equation (8) is a saturation function, and is defined by the following equation (11).

In equation (11), θ _BL is the overall gear backlash amount from the motor to the drive shaft.

  From equations (5) to (10), the transmission characteristics from the torque command value to the drive shaft torsion angle can be expressed by the following equations (12) to (14).

However, equation (13) is represented by p ₁ in _{(14), p 0, a} 3, a 2, a 1, a 0 , respectively, the following equation (15). Ζ _p is a damping coefficient of the driving torque transmission system, and ω _p is a natural vibration frequency of the driving torque transmission system.

  Therefore, the drive shaft torque is expressed by the following equation (16) from the equations (8) and (12).

  Here, the normative response of the drive shaft torque is defined by the following equations (17) and (18).

Where ζ _m and ω _m are the damping coefficient and natural vibration frequency of the ideal model, respectively.

When obtaining the torque command value such as a drive shaft torque T _d and the motor torque T _m are identical, the following equation (19) and (20).

Therefore, the configuration of the vibration suppression control FF calculation unit 401 includes a linear filter G _INV (s) for reducing the natural vibration frequency component of the torque transmission of the vehicle, a filter G _t (s) for calculating the drive shaft torsion angle, The lower limit value is expressed in FIG. 6 by a saturation function St (limiter) defined by St (θ), and a filter F _s (s) that compensates for a phase shift caused by a wheel inertia of a drive shaft torsion angle and tire friction force. The Referring to FIG. 6, the vibration suppression control FF calculation unit 401 includes a control block 601 having a transfer characteristic G _INV (s), a control block 602 having a transfer characteristic G _t (s), and an expression (11 ), A control block 604 having a transfer characteristic F _s (s), an adder 605, an adder 606, and a subtractor 607.

The adder 605 adds the first torque target value FF _out that is the output of the subtracter 607 and the output of the control block 604.

  The control block 602 outputs the torsion angle θ of the drive shaft as a calculation result based on the addition result of the adder 605.

  The limiter 603 limits the drive shaft torsion angle θ output from the control block 602 to a predetermined upper limit value when the drive shaft torsion angle θ exceeds a predetermined upper limit value. When the value is below the lower limit value, the predetermined lower limit value is set.

  The control block 604 compensates for the phase shift caused by the wheel inertia of the drive shaft twist angle and the tire friction force with respect to the limit value St (θ) of the drive shaft twist angle after the upper and lower limit values are limited by the limiter 603.

The adder 606 adds the target torque command value Tm1 ^* and the output of the control block 604.

  The control block 601 reduces the natural vibration frequency component of the torque transmission of the vehicle with respect to the addition result of the adder 606.

The subtractor 607 calculates FF _out which is a deviation between the output of the control block 601 and the output of the control block 604, and outputs the calculated value as the first torque target value FF _out .

  Further, by substituting the equation (19) into the equation (12), an equivalent conversion to the following equation (21) can be performed.

Therefore, the vibration suppression control FF calculation unit 401 has a filter G _tm (s) for calculating an ideal response of the drive shaft torsion angle, a saturation function St (limiter), a wheel inertia of the drive shaft torsion angle, and a phase of the tire friction force. As shown in FIG. 7, a filter F _s (s) that compensates for the deviation and a linear filter G _INV (s) that reduces the natural vibration frequency component of the torque transmission of the vehicle as shown in FIG. It can also be configured. According to the configuration illustrated in FIG. 7, the vibration suppression control FF calculation unit 401 includes a control block 701 having a transfer characteristic G _INV (s), a limiter 703 having a characteristic represented by Expression (11), and F _s ( s), a control block 704 having a transfer characteristic, an adder 706, a subtractor 707, a control block 702 having a transfer characteristic _Gtm (s), and an adder 705, and a first torque target value Based on the target torque command value Tm1 ^* without feedback of FFout, the same vibration damping control effect as the vibration damping control with the configuration shown in FIG. 6 can be realized.

  Next, feedback calculation processing performed by the vibration suppression control FB calculation unit 402 will be described.

FIG. 8 is a detailed block diagram of the vibration suppression control FB calculation unit 402. The vibration suppression control FB calculation unit 402 includes a control block 801 having a transfer characteristic of G _p (s), a control block 802 having a transfer characteristic of G _ps (s), and H (s) / G _p (s). A control block 805 having a transfer characteristic, an adder 808, a subtractor 809, a control block 806 having a transfer characteristic G _t (s), a limiter 803 having a characteristic expressed by the equation (11), and F _s A control block 804 having a transfer characteristic (s) and an adder 810 are provided.

G _p (s) is a linear plant model indicating the transfer characteristic of the motor rotation speed with respect to the motor torque input to the vehicle, and G _ps (s) is the twist angle St (θ) of the drive shaft that is the output of the limiter 803. Is a transfer function for calculating the backlash compensation amount of the motor rotation speed based on G _t (s) is a filter that calculates the drive shaft torsion angle. F _s (s) is a filter that compensates for the phase shift caused by the wheel inertia of the drive shaft torsion angle and the tire friction force, and is specifically expressed by equations (13) and (14).

The vibration suppression control FB calculation unit 402 having such a configuration is based on the final torque target value Tm2 ^* after the vibration suppression control and the first torque target value FF _out which is the output of the vibration suppression control FF calculation unit 401. The motor rotational speed estimated value ωm ^ is calculated from the linear plant model G _p (s), filter G _t (s), filter F _s (s), saturation function S _t (limiter), and transfer function G _ps (s). .

Further, based on the calculated motor rotation speed estimated value ωm ^ and the difference between the actual motor rotation speed ωm, the second output which is the output of the vibration suppression control FB calculation unit 402 is obtained from the transfer function H (s) / Gp (s). The torque target value FB _{out of} is calculated. The transfer characteristic H (s) is set so that the difference between the denominator order and the numerator order of the transfer characteristic H (s) is equal to or greater than the difference between the denominator order and the numerator order of the transfer characteristic Gp (s). .

Then, the adder 404 adds the first torque target value FFout, which is the output of the vibration suppression control FF calculation unit 401, and the second torque target value FBout, which is the output of the vibration suppression control FB calculation unit 402. Then, a final torque target value Tm2 ^* is calculated.

Note that the configuration of the vibration suppression control FB calculation unit 402 is not limited to the configuration illustrated in FIG. 8, and the drive shaft torsion angle limit value St (θ calculated by the vibration suppression control FF calculation unit 401 is illustrated in FIG. 9. ) _May be the input of the transfer function G _ps (s).

The linear plant model G _p (s) indicating the transfer characteristic of the motor rotation speed with respect to the motor torque input to the vehicle and the transfer function G _ps (s) for calculating the backlash compensation amount of the motor rotation speed will be described below.

  Expressions (5) to (10) are subjected to Laplace conversion, and transmission characteristics from the torque command value to the motor angular velocity are obtained, and can be expressed by the following expressions (22) to (24).

However, b ₃ , b ₂ , b ₁ , b ₀ , c ₂ , and c ₁ in the formulas (23) and (24) are each expressed by the following formula (25).

By arranging the equation (23), Gp (s) can be expressed as the following equation (26). In a general vehicle, when the poles and zeros of the transfer function of Equation (26) are examined, one pole and one zero show extremely close values. This corresponds to the fact that α and β in Equation (26) show extremely close values. Here, ζ _p and ω _p are the damping coefficient and natural vibration frequency of the drive shaft torsional vibration system, respectively.

Therefore, by performing pole-zero cancellation (approximate with α = β) in equation (26), the transfer characteristic G _p (s) of (second order) / (third order) is obtained as shown in the following equation (27). Configure.

  Next, the transfer function H (s) will be described. H (s) is a feedback element that reduces only vibration when a band-pass filter is used. At this time, the greatest effect can be obtained by setting the filter characteristics as shown in FIG. That is, the transfer function H (s) has substantially the same attenuation characteristics on the low-pass side and the high-pass side, and the torsional resonance frequency of the drive system is close to the center of the passband on the logarithmic axis (log scale). Is set to In order to realize this, when H (s) is composed of a primary high-pass filter and a primary low-pass filter, the frequency fp is the torsional resonance frequency of the drive system, k is an arbitrary value, and H (s) is It is expressed as equation (28).

_{However, τ L = 1 / (2πf} HC), f HC = k · f p, τ H = 1 / (2πf LC), it is f _LC = f _p / k.

  Next, details of the control backlash amount calculation unit 403 (see FIG. 4), which are characteristic of the control apparatus for an electric vehicle according to the present embodiment, will be described.

  The vibration suppression control FF calculation unit 401 and the vibration suppression control FB calculation unit 402 (hereinafter collectively referred to simply as a compensator) transmit torque in consideration of the dead zone of the vehicle driving force transmission system as described above. Since it is configured to reduce the vibration of the system, the natural frequency component of the torque transmission system such as the drive shaft torsional vibration can be suppressed even when the gear backlash occurs.

Here, the gear backlash amount compensated by the compensator is determined based on the gear backlash amount θ _BL used for setting the upper and lower limit values of the saturation function St (see Expression (11)). This gear backlash amount θ _BL is an overall gear backlash amount from the electric motor 4 to the drive shaft 8 that is set in advance for use during normal driving, and is obtained from a vehicle design value or a previously conducted experiment. This is a value obtained from experimental values.

However, if the braking force due to the intervention of the friction brake 10 acts on the driving shaft 8 when the rotation of the driving shaft 8 passes through the gear backlash section, the gear in the actual vehicle is clogged according to the magnitude of the braking force. And the time assumed based on the equation (11) in which the gear backlash amount θ _BL is set, the apparent gear backlash amount in the actual vehicle changes. As a result, an error occurs between the gear backlash amount compensated in the compensator and the gear backlash amount to be compensated in the actual vehicle. If the drive shaft torque is controlled with this error occurring, the torque controllability deteriorates. For this reason, when the braking force due to the intervention of the friction brake 10 acts on the drive shaft 8 when passing through the gear backlash section, a sense of incongruity due to a delay in the rise of torque or acceleration vibration (acceleration shock due to drive shaft torsional vibration). ) Occurs.

  For example, when the brake braking amount that gives the braking force is input to the drive shaft 8 at a substantially constant value, the gear backlash tends to be clogged because the drive shaft side gear decelerates. Rush amount is reduced. As a result, the final torque target value does not rise until the vehicle state assumed by the compensator matches the state that has passed the gear backlash, even though the actual vehicle has already passed the gear backlash section. A response delay with respect to the target torque command value occurs. As a result, there is a scene in which the torque does not rise despite passing through the gear backlash, and the vehicle occupant feels a sense of incongruity such as a stagnation due to a delay in the rise of the torque.

  In addition, if the brake braking amount input to the drive shaft 8 in the gear backlash section becomes zero before the gear backlash is completely clogged, the motor shaft side gear is driven immediately after the brake braking is released. Since the rotation of the shaft side gear may become faster, the gear backlash is less likely to be clogged, and the apparent gear backlash amount in an actual vehicle increases. Then, the final torque target value rises based on the vehicle state assumed by the compensator, even though the actual vehicle is passing through the gear backlash section. As a result, the torque rises sharply while passing through the gear backlash, causing an acceleration shock to the vehicle.

In the processing described below, the control backlash amount calculation unit 403 shown in FIG. 4 adjusts the gear backlash amount θ _BL used for setting the upper and lower limit values of the saturation function St according to the friction brake braking amount, and compensates for it. By suppressing the deterioration in torque controllability caused by the error between the gear backlash amount to be compensated based on the vehicle condition assumed by the device and the apparent gear backlash amount in the actual vehicle, The purpose is to reduce the sense of incongruity due to delay and acceleration shock caused by drive shaft torsional vibration. Details will be described below with reference to FIG.

11, according to the adjustment of the gear backlash amount theta _BL used in the upper and lower limits of the saturation function St which compensator having a flowchart showing the flow of the gear backlash amount set value calculation processing.

  In step S1101, the electric motor controller 2 determines the gear backlash amount to be compensated for in the actual vehicle based on the friction brake braking amount, and the gear backlash amount that the compensator compensates based on the upper and lower limit values of the saturation function St. It is determined whether or not an error occurs. As described above, the electric motor controller 2 functions as a compensation amount adjustment permission determination unit that determines whether or not it is necessary to adjust the compensation amount with respect to the gear backlash amount.

  In step S1102, the electric motor controller 2 determines the gear backlash amount to be compensated for in the actual vehicle based on the friction brake braking amount and the final torque target value, and the compensator is based on the upper and lower limit values of the saturation function St. It is determined whether or not the error from the gear backlash amount to be compensated has been eliminated. That is, the electric motor controller 2 returns the gear backlash amount compensated by the compensator in the vibration suppression control calculation unit 400 to the overall gear backlash amount from the electric motor 4 to the drive shaft 8 which is the original compensation amount. It functions as a compensation amount adjustment non-permission determination unit for determining whether or not.

In step S1103, the gear backlash amount θ _BL used for the upper and lower limit values of the saturation function St is calculated based on the determination results in steps S1101 and S1102.

  Hereinafter, details of the processing executed in steps S1101 to S1103 will be described.

  FIG. 12 is a flowchart showing the flow of processing executed in step S1101.

In step S1201, the electric motor controller 2 determines whether the friction brake braking amount is larger than a predetermined value. When the friction brake braking amount is larger than the predetermined value, there is an error between the gear backlash amount to be compensated in the actual vehicle by the intervention of the friction brake 10 and the gear backlash amount compensated based on the upper and lower limit values of the saturation function St. occurs is determined that, for setting the permit gear backlash calculation permission determination value as the indication of whether the computing the appropriate settings of the gear backlash theta _BL in the process of a subsequent stage, the following step S1202 Execute the process.

  Note that the predetermined value here is an appropriate value obtained in advance by experiment or the like to determine the brake braking amount that may cause an error between the gear backlash amount compensated in the compensator and the gear backlash amount to be compensated in the actual vehicle. However, it is a value determined by the relationship with the vehicle design value. When the brake braking amount in the gear backlash section is larger than 0, an error may occur between the vehicle state assumed by the compensator and the actual vehicle state, so the lower limit value of the predetermined value is 0.

  In step S1202, the electric motor controller 2 sets the gear backlash amount calculation permission determination value that is an index as to whether or not to perform adjustment of the compensation amount for the gear backlash in the subsequent process (step S1103) to be permitted. And the electric motor controller 2 complete | finishes the process which concerns on FIG. 12, and performs the process of subsequent step S1102 of FIG.

  If the friction brake braking amount is equal to or less than the predetermined value in step S1201, the permission / non-permission determination relating to the adjustment of the gear backlash amount to be compensated is not performed, and the gear backlash amount compensation amount adjustment non-permission determination according to step S1102 is performed. Therefore, the compensation amount adjustment permission determination process according to FIG. 12 is terminated. The control gear backlash amount calculation permission determination value holds the gear backlash amount calculation permission determination value related to the previous process including the determination result of step S1102 one cycle before.

  In step S1102 (see FIG. 11), the electric motor controller 2 determines whether or not to prohibit the execution of the arithmetic processing for adjusting the gear backlash amount (compensation amount adjustment non-permission determination).

  FIG. 13 is a flowchart showing the process related to the gear backlash amount compensation amount adjustment non-permission determination executed in step S1102.

  In step S1301, the electric motor controller 2 determines whether the friction brake braking amount is larger than a predetermined value. When it is larger than the predetermined value, there is an error between the vehicle state assumed by the compensator and the actual vehicle state, and the state in which the gear backlash amount needs to be adjusted continues from the time of processing in step S1101. Therefore, the gear backlash amount calculation permission determination value is held in a permission state, and the process related to the compensation amount adjustment non-permission determination is terminated. When the friction brake braking amount is equal to or less than the predetermined value, that is, when it is determined that there is no intervention of the friction brake 10 that causes an error, the process of the subsequent step S1302 is executed.

In step S1302, the electric motor controller 2 determines whether or not the final torque target value calculated by the vibration suppression control calculation unit 400 is greater than a predetermined value. If the friction brake braking amount is less than the predetermined value and the final torque target value is larger than the specified value, it is considered that at least the error between the vehicle state assumed by the compensator and the actual vehicle has been eliminated. It is necessary to return the gear backlash amount compensated by the device to the value corresponding to the overall gear backlash amount θ _BL which is the original setting value.

  For this reason, when the final torque target value is larger than the predetermined value in step S1302, the process of step S1303 for setting the compensation amount adjustment permission determination value to non-permission is executed. Note that the default value here is an appropriate value obtained in advance by experiment or the like for the final torque target value that can be determined that there is no error between the vehicle state assumed by the compensator and the actual vehicle, or that the error has been eliminated. However, it is a value determined by the relationship with the vehicle design value.

  In step S1303, the electric motor controller 2 disallows the gear backlash amount calculation permission determination value that is an index as to whether or not to execute the process related to the adjustment of the gear backlash amount to be compensated in the subsequent process (step S1103). Then, the process of step S1103 in FIG. 11 is executed.

  If the friction brake braking amount is larger than the predetermined value in step S1301, or if the final torque command value is less than or equal to the predetermined value in step S1302, the electric motor controller 2 is permitted / not permitted for adjusting the gear backlash amount. The determination is not performed, the gear backlash amount calculation permission determination value set at the time of step S1101 (see FIG. 11), which is the preceding process, is retained, and the subsequent process of step S1103 is executed.

In step S1103 (see FIG. 11), the electric motor controller 2 sets the upper and lower limit values in the saturation function St according to the gear backlash amount calculation permission determination value set in the processing according to step S1101 or step S1102. The process of setting the value of the gear backlash amount θ _d ^* used in the above is executed. The gear backlash amount θ _d ^* is a value that is substituted for the gear backlash amount θ _BL in the equation (11) that constitutes the saturation function St. The preset gear backlash amount θ _BL is the overall gear backlash amount from the electric motor 4 to the drive shaft 8 determined from the vehicle design value, etc., and therefore by changing this value, the gear backlash in the compensator The compensation amount for the rush amount can be adjusted. The process of setting the value of the gear backlash amount θ _d ^* is executed according to the flowchart shown in FIG.

Figure 14 is executed in step S1103, the gear backlash amount calculation processing, and is a flowchart showing the flow of processing for setting the value of the gear backlash theta _BL based on the calculation result.

In step S1401, the electric motor controller 2 determines the gear backlash amount calculation permission determination value set in the processing of steps S1101 and S1102 described above. If the determination value is permitted, an error has occurred between the actual vehicle and the vehicle state assumed by the compensator, so the gear backlash amount θ _BL used for setting the upper and lower limit values of the saturation function St is adjusted. Steps S1402 and S1403 are executed. When the gear backlash amount calculation permission determination value is not permitted, the actual vehicle and the vehicle state assumed by the compensator are in a state of coincidence, and therefore used for setting the upper and lower limit values of the saturation function St. The process of step S1404 is executed to set the gear backlash amount θ _d ^* to the original set value set in advance.

In step S1402, the electric motor controller 2 determines the optimum gear back according to the friction brake braking amount based on the relational expression (see FIG. 15) between the friction brake braking amount and the gear backlash amount to be compensated by the compensator. Calculate the rush amount θ _d1 .

FIG. 15 is a relational diagram showing the relationship between the friction brake braking amount and the gear backlash amount to be compensated for by the compensator, which are determined from vehicle design values and experimental values obtained by experiments conducted in advance. The horizontal axis represents the friction brake braking amount, and the vertical axis represents the gear backlash amount to be compensated. The gear backlash amount when the friction brake braking amount is 0 is the overall gear backlash amount θ _d0 from the electric motor 4 to the drive shaft 8. The gear backlash amount θ _d0 is the same value as the overall gear backlash amount from the electric motor 4 to the drive shaft 8 that is set in advance during normal travel. As shown in FIG. 15, it can be seen that the gear backlash amount θ _d1 to be compensated by the compensator decreases as the friction brake braking amount increases with respect to the gear backlash amount θ _d0 .

  As described above, when the braking force by the friction brake 10 acts on the drive shaft 8 of the vehicle, there is an error between the time until the gear is clogged in the actual vehicle and the time until the gear assumed by the compensator of the conventional setting value is clogged. As a result, the apparent amount of gear backlash changes.

In the present embodiment, the gear backlash amount θ _d ^* is smaller than the gear backlash amount θ _d0 in both cases where the apparent gear backlash amount decreases and increases due to the action of the brake braking amount. The gear backlash amount θ _d1 calculated according to the brake braking amount is set based on the relationship diagram shown in FIG.

  As a result, when the apparent gear backlash amount is reduced by the action of the brake braking force, the gear backlash amount compensated by the vehicle model 503 and the gear backlash amount to be compensated in the actual vehicle are substantially the same. Therefore, it is possible to eliminate the error caused by the intervention of the friction brake 10 between the actual vehicle and the vehicle state assumed by the compensator, and to suppress the deterioration of the torque controllability.

  Even if the apparent gear backlash amount increases, the drive shaft torque rises slowly from an early timing by setting the gear backlash amount compensated by the compensator to be smaller, and the drive shaft side gear On the other hand, since the motor shaft side gear can be gradually closed, it is possible to reduce the acceleration shock accompanying the deterioration of the torque controllability.

Therefore, in step S1403 of FIG. 14, the electric motor controller 2 performs a process for setting the gear backlash theta _d1 is smaller than the gear backlash theta _d0 to gear backlash theta _d ^*. In the subsequent process of step S1405, the gear backlash amount θ _d ^* in which the gear backlash amount θ _d1 is set is used as the gear backlash amount θ _BL used when setting the upper and lower limits of the saturation function of the compensator ^. And Thereby, the deterioration of the torque controllability caused by the error between the actual vehicle caused by the intervention of the friction brake 10 and the vehicle state assumed by the compensator can be suppressed.

  On the other hand, when the compensation amount adjustment permission determination value is not permitted, the actual vehicle and the vehicle state assumed by the compensator are in a state that matches, so the compensation amount of the gear backlash amount in the compensator is In order to obtain the original set value, the process of step S1404 is executed.

In step S < _b ^> 1404, the electric motor controller 2 sets the gear backlash amount θ _d ^* compensated by the compensator to the overall gear backlash amount θ _d0 from the electric motor 4 to the drive shaft 8. The gear backlash amount θ _d0 is a value obtained from a vehicle design value or an experimental value obtained by a previous experiment, and is the same value as the gear backlash amount θ _BL set in advance in the above equation (11). is there. In the subsequent process of step S1405, the gear backlash amount θ _d ^* in which the gear backlash amount θ _d0 is set is used as the gear backlash amount θ _BL used when setting the upper and lower limit values of the saturation function of the compensator ^. And

  Thereby, it is possible to return to the vibration suppression control by the compensator in which the gear backlash amount (compensation amount) of the conventional setting value determined based on the vehicle design value or the like is set, so that disturbance due to the intervention of the friction brake 10 is prevented. In addition, the drive shaft torsional vibration at the time of passing through the gear backlash section can be appropriately suppressed even in a situation where an error between the actual vehicle and the vehicle state assumed by the compensator does not occur.

  Thus, the vehicle state calculation process including adjustment of the compensation amount for the gear backlash shown in FIG. 11 is completed. By this processing, the gear backlash amount compensated in the compensator can be made variable according to the friction brake braking amount. Thereby, the final torque target value suitable for the actual vehicle state can be calculated. As a result, even when the braking force due to the intervention of the friction brake 10 acts on the drive shaft of the vehicle in the section passing through the gear backlash, the drive shaft torsional vibration of the vehicle and the occupant are not deteriorated without deteriorating torque controllability. The feeling of strangeness can be effectively suppressed.

  Here, with regard to drive shaft torque control (vibration control) in a scene that passes through the gear backlash section, a comparison between a control result of the electric vehicle control device of the first embodiment and a control result of the conventional example is shown in FIG. The description will be given with reference.

  FIG. 16 is a time chart showing an example of a control result when the control device of the first embodiment is applied to an electric vehicle and a control result according to a conventional example. FIG. 16 shows the target torque command value, the final torque target value, the brake braking amount, and the longitudinal acceleration of the vehicle in order from the top. Moreover, the broken line in the chart which shows a final torque target value and a longitudinal acceleration shows the control result by a comparative example.

  FIG. 16 shows that on a flat road, the driver slowly releases the brake pedal from the state where the friction brake and the motor regenerative brake are in a coordinated control state, and switches to the accelerator pedal. It is a time chart in the scene where a motor torque reverses from negative to positive and passes through a gear backlash when a pedal is gently depressed. In such a situation, the brake braking amount that was input during the gear backlash becomes zero, so that the rotation of the drive shaft side gear becomes faster than the rotation of the motor side shaft gear. The amount of rush increases.

  From around time t0.5 to t5, the brake pedal is gently released, so the brake braking amount gradually decreases. At time t5, the brake pedal is completely released, and the brake braking amount becomes zero. At the same time, the accelerator pedal is gradually depressed, and the target torque command value gradually increases after time t5.

  By the way, at time t0 to t6, the motor torque reverses from negative to positive, and therefore passes through the gear backlash section. At this time, in the vibration suppression control considering the backlash of the gear, the final torque target value is raised again from the time when the gear is jammed while keeping the final torque target value constant until the gear is jammed. If a disturbance such as a braking force due to the friction brake does not occur during the passage of the gear backlash section, the timing at which the vehicle gear is jammed coincides with the timing at which the final torque target value rises.

  However, in the case of this time chart, since the intervention of the friction brake 10 continues when passing through the gear backlash section relating to t0 to t5, a brake braking amount that becomes a disturbance is applied to the drive shaft 8 of the vehicle. ing.

  In the conventional example, since the influence of disturbance related to the brake braking amount is not considered in the saturation functions of the vibration suppression control FF calculation unit 401 and the vibration suppression control FB calculation unit 402, respectively, the vibration suppression control FF calculation unit 401 and the vibration suppression control FF calculation unit 401 Vibration suppression control is executed in a state where an error has occurred between the assumed vehicle state and the actual vehicle in vibration control FB calculation unit 402. For this reason, torque controllability deteriorates, and the final torque target value rises before the gear is jammed at time t6 to t7. For this reason, from the relationship with the action of the F / B compensator for vibration suppression control, an acceleration shock accompanying a sharp rise in the longitudinal acceleration occurs in the vehicle near time t6.5.

On the other hand, in the case of the control according to the first embodiment, the gear backlash amount θ _BL for setting the upper and lower limit values in the saturation function St is set to an appropriate value according to the actual vehicle state according to the brake braking amount. Adjust to. In this time chart, the upper and lower limit values of the saturation function St are optimal based on the relationship diagram shown in FIG. 15 by detecting a brake braking amount exceeding a predetermined value generated by the driver depressing the brake pedal 13. Set to the correct value. That is, the gear backlash amount compensated by the compensator is set to zero.

  As a result, the drive shaft torque is controlled assuming that there is no dead band width based on the gear backlash amount in the drive force transmission system. Therefore, at time t5, the final torque target value starts to increase following the target torque command value. . As a result, the motor shaft side gear is gradually clogged with the drive shaft side gear at an early timing. Therefore, in this embodiment, the final torque target value at the timing when the gear is clogged (near a) is the timing when the gear is clogged in the comparative example (near b) ) Is a value lower than the final torque command value. As a result, the rapid increase in longitudinal acceleration that occurs at the timing when the gear is jammed can be reduced compared to the comparative example (see times t6 to t7), so that the acceleration shock generated in the vehicle is more effective than the conventional example. Can be suppressed.

  As described above, the control device for the electric vehicle according to the first embodiment sets the torque command value based on the vehicle information, compensates for the dead zone in which the motor torque is not transmitted to the drive shaft of the vehicle, and is unique to the drive force transmission system of the vehicle. A torque target value is calculated by performing a filtering process for reducing the vibration frequency component on the torque command value, and the torque of the motor 4 is controlled based on the torque target value. Then, the compensation amount for the dead zone based on the backlash considered in the filtering process is adjusted according to the friction brake braking amount that applies a braking force to the vehicle. As a result, the compensation amount of the gear backlash amount can be adjusted according to the vehicle state signal such as the friction brake braking amount, so that the deterioration of the torque controllability can be suppressed and an appropriate drive shaft torque corresponding to the vehicle situation can be suppressed. Since control becomes possible, it is possible to avoid a deterioration in riding comfort due to an error between the vehicle state assumed by the compensator and the actual distance between vehicles.

  In addition, when adjusting the compensation amount for the gear backlash according to the friction brake braking amount, the control device for the electric vehicle according to the first embodiment uses the gear backlash amount compensated by the compensator as the friction brake braking amount. The compensation amount is adjusted by reducing the corresponding amount. As a result, the optimum gear backlash amount to be compensated by the compensator can be adjusted according to the friction brake braking amount, so that even if a disturbance due to the friction brake 10 occurs when the gear backlash section elapses, it is appropriate. Drive shaft torque control can be realized.

Further, the control device for the electric vehicle according to the first embodiment, when adjusting the compensation amount for the gear backlash according to the friction brake braking amount, when the friction brake braking amount is equal to or less than a predetermined value, and When at least one of the cases where the motor torque command value exceeds a predetermined value is established, the compensation amount adjusted according to the friction brake braking amount is returned to the original compensation amount. The original compensation amount is a compensation amount during normal traveling of the vehicle, and is a compensation amount corresponding to the overall gear backlash amount θ _BL from the motor 4 to the drive shaft 8 in equation (11). .

Further, the control device for the electric vehicle according to the first embodiment adjusts the compensation amount for the gear backlash by reducing the gear backlash amount θ _BL compensated by the compensator in accordance with the friction brake braking amount. As a result, torque controllability due to modeling errors between the actual vehicle and the vehicle state assumed by the compensator can be achieved with a small amount of calculation that only requires changing the setting of the gear backlash amount θ _d ^* based on the friction brake braking amount. Can be reduced, and the drive shaft torsional vibration suppressing effect and the like as described above can be realized.

-Second Embodiment-
The control device for the electric vehicle according to the second embodiment also suppresses deterioration of torque controllability caused by an error between the actual vehicle when the gear backlash occurs and the vehicle state assumed by the compensator. However, the suppression method is different from that of the first embodiment.

  Specifically, the processing contents in step S1103 described above are different from those in the first embodiment. Details will be described below with reference to FIG.

  FIG. 17 sets the gear backlash amount θBL used for the gear backlash amount calculation process executed in step S1103 in the second embodiment and the upper and lower limit values of the saturation function St executed based on the calculation result. It is the flowchart which showed the flow of the process to perform.

In step S1701, the electric motor controller 2 determines the gear backlash amount calculation permission determination value set in the processing of steps S1101 and S1102 described above. If the determination value is permitted, there is an error between the actual vehicle and the vehicle state assumed by the compensator, so the gear backlash amount θ _BL used when setting the upper and lower limit values used by the saturation function St. The process of step S1702 for adjusting is executed. When the gear backlash amount calculation permission determination value is not permitted, the upper and lower limit values used by the saturation function St are set because the actual vehicle and the vehicle state assumed by the compensator are in agreement. The process of step S1703 is executed with the gear backlash amount θ _d ^* used at the time as the original set value.

In step S1702, the electric motor controller 2 sets the gear backlash amount θ _d ^* to zero. In the subsequent step S1704, the gear backlash amount θ _d ^* is substituted for the gear backlash amount θ _BL used to set the upper and lower limit values of the saturation function of the compensator, so that the gear compensated by the compensator The backlash amount is set to zero.

Then, since the dead zone due to the gear backlash is not considered in the vehicle state assumed in the compensator, the target torque command value input to the vibration suppression control FF calculation unit 401 does not take into account compensation for the gear backlash. 6 and 7 are input to a control block 601 or 701 (hereinafter referred to as inverse filters 601 and 701) related to the linear filter G _INV (s).

Here, the inverse filters 601 and 701 are configured to reduce the natural vibration frequency component of the torque transmission system of the vehicle, and the output value follows the input value. For this reason, when the compensation amount for the gear backlash in the compensator is set to zero in step S1704, the first torque follows the target torque command value Tm1 ^* that is the input of the vibration suppression control FF calculation unit 401. The target value FF _out is output. Since the final torque target value Tm2 ^* follows the first torque target value FF _out , as a result, the final torque target value Tm2 ^* rises following the target torque command value Tm1 ^* as an input.

  Thus, when the friction brake braking amount is larger than the predetermined value in the gear backlash section, the upper and lower limit values in the saturation function St are set to 0, and the torque target value is calculated using the inverse filter 601 or 701. Even in the gear backlash section, the final torque target value can be raised following the target torque command value. As a result, it is possible to avoid a situation in which the torque does not rise despite passing through the gear backlash, or a case where the torque rises steeply while passing through the gear backlash. A sense of incongruity and a drive shaft torsional vibration that a passenger feels can be effectively suppressed.

On the other hand, when the compensation amount adjustment permission determination value is non-permitted, the actual vehicle and the vehicle state assumed by the compensator are in a state that matches, so in the compensator as in the first embodiment. In order to set the compensation amount of the gear backlash amount to the original set value, the process of step S1703 is executed. In other words, the electric motor controller 2 sets the gear backlash amount θ _BL used when setting the upper and lower limits of the saturation function of the compensator to the gear backlash amount θ _d0 .

  Thereby, it is possible to return to the vibration suppression control by the compensator in which the gear backlash amount (compensation amount) of the conventional setting value determined based on the vehicle design value or the like is set, so that disturbance due to the intervention of the friction brake 10 is prevented. In addition, the drive shaft torsional vibration in the gear backlash section can be appropriately suppressed even in a scene where an error between the actual vehicle and the vehicle state assumed by the compensator does not occur.

  In the vibration suppression control by the control device for the electric vehicle in the second embodiment, a control result similar to the control result described with reference to FIG. 16 in the first embodiment can be obtained.

  As described above, the control device for an electric vehicle according to the second embodiment uses the inverse filter 601 or 701 to cancel the vibration characteristics of the vehicle model when the friction brake braking amount is larger than a predetermined default value. By calculating the value, the compensation amount for the gear backlash is adjusted. As a result, the final torque target value rises following the target torque command value while passing through the gear backlash section, so that the drive shaft torsional vibration can be effectively suppressed as in the first embodiment.

  The present invention is not limited to the embodiment described above. For example, although the friction brake braking amount used in the above description is a value based on the friction brake braking amount command value or the detected value of the brake operation amount, it is not necessarily limited thereto. Other means for detecting only whether or not it is used may be provided, and the compensation amount for the gear backlash amount may be adjusted based on the result of the means.

  Further, the amount of friction brake braking indicated as a disturbance during gear backlash considered in the above description is not limited to the amount of friction brake braking caused by the brake pedal 13, but air acting on the drive shaft 8 of the speed reducer of the vehicle. Other resistance components such as resistance may be included.

2. Electric motor controller (torque command value setting unit, torque target value calculation unit, motor torque control unit, compensation amount adjustment unit)
DESCRIPTION OF SYMBOLS 4 ... Electric motor 5 ... Reduction gear 8 ... Drive shaft 11 ... Brake controller 13 ... Brake pedal 13a ... Stroke sensor (brake operation amount detection part)

Claims (9)

In the control method of the electric vehicle for controlling the torque of the motor connected to the drive wheel,
Set torque command value based on vehicle information,
A torque target value is calculated by applying a filtering process to the torque command value that compensates for the dead zone in which the motor torque is not transmitted to the drive shaft of the vehicle and reduces the natural vibration frequency component of the drive force transmission system of the vehicle,
Controlling the torque of the motor based on the torque target value;
Adjusting a compensation amount for the dead zone considered in the filtering process according to a friction brake braking amount that applies a braking force to the vehicle;
An electric vehicle control method characterized by the above. In the control method of the electric vehicle according to claim 1,
The dead zone width of the driving force transmission system is the sum of the gear backlash amounts from the motor to the driving shaft.
An electric vehicle control method characterized by the above. In the control method of the electric vehicle according to claim 1 or 2,
A brake operation amount detection unit for detecting a driver's brake operation amount;
The friction brake braking amount is a detected value of the brake operation amount, or a friction braking amount command value calculated based on the detected value.
An electric vehicle control method characterized by the above. In the control method of the electric vehicle according to any one of claims 1 to 3,
When adjusting the compensation amount according to the friction brake braking amount, a process of reducing the compensation amount according to the friction brake braking amount is performed.
An electric vehicle control method characterized by the above. In the control method of the electric vehicle according to any one of claims 1 to 4,
When adjusting the compensation amount according to the friction brake braking amount, when the brake braking amount is equal to or less than a predetermined value, the compensation amount adjusted according to the friction brake braking amount is restored to the original compensation amount. Return to quantity,
An electric vehicle control method characterized by the above. In the control method of the electric vehicle as described in any one of Claim 1 to 5,
When adjusting the compensation amount according to the friction brake braking amount, when the motor torque command value exceeds a predetermined value, the compensation amount adjusted according to the friction brake braking amount is restored to the original compensation amount. Return to quantity,
An electric vehicle control method characterized by the above. In the control method of the electric vehicle according to claim 1,
When adjusting the compensation amount according to the friction brake braking amount, the dead zone width compensated in the vehicle model is adjusted by reducing according to the friction brake braking amount.
An electric vehicle control method characterized by the above. In the control method of the electric vehicle according to claim 1,
When the friction brake braking amount is larger than a predetermined default value, the compensation amount for the dead zone is adjusted by applying a filtering process to the torque command value by a linear filter that cancels the vibration characteristic of the driving force transmission system of the vehicle. To
An electric vehicle control method characterized by the above. In the control device for an electric vehicle that controls the torque of the motor connected to the drive wheel,
A torque command value setting unit for setting a torque command value based on vehicle information;
Torque target value calculation that calculates a torque target value by applying a filtering process to the torque command value that compensates for the dead band in which the motor torque is not transmitted to the vehicle drive shaft and reduces the natural vibration frequency component of the vehicle drive force transmission system And
A motor torque controller for controlling the torque of the motor based on the torque target value;
A compensation amount adjusting unit that adjusts a compensation amount for the dead zone considered in the filtering process according to a friction brake braking amount that applies a braking force to the vehicle.
A control apparatus for an electric vehicle.