JP6191777B2 - Electric vehicle control device and electric vehicle control method - Google Patents

Description

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

  Conventionally, there has been known a control device that suppresses drive shaft torsional vibration by constructing a pseudo drive shaft torsion angular velocity feedback system using a vehicle model that models characteristics from the torque of an electric motor to the drive shaft torsion angular velocity. (WO / 2013 / 157315A).

  However, even if a vehicle model simulating a real vehicle in detail is used, if a disturbance occurs due to changes in the surrounding environment (running resistance, etc.) of the vehicle or friction brake intervention, the vehicle model and the actual vehicle An error occurs with the above behavior, and the drive shaft torsional vibration cannot be suppressed with high accuracy.

  An object of the present invention is to provide a technique for accurately suppressing drive shaft torsional vibration even when disturbance occurs.

  An electric vehicle control device according to an aspect of the present invention is a control device for an electric vehicle that sets a target torque command value based on vehicle information and controls the torque of a motor connected to a drive wheel, the target torque command value, And at least a part of the disturbance acting on the vehicle, feedforward calculation means for calculating the first torque target value by feedforward calculation, and motor torque control means for controlling the motor torque according to the first torque target value With. The feedforward calculation means is a vehicle model that models characteristics from motor torque and disturbance to drive shaft torsional angular velocity, and inputs a target torque command value and at least a part of the disturbance acting on the vehicle, and drive shaft torsion A vehicle model that outputs an angular velocity, and a drive shaft torsion angular velocity feedback model that calculates a first torque target value by feeding back a drive shaft torsion angular velocity output from the vehicle model to a target torque command value.

  Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating a main configuration of an electric vehicle including a control device for an electric vehicle according to the first embodiment. FIG. 2 is a flowchart showing a flow of processing performed by the motor controller. FIG. 3 is a diagram illustrating an example of an accelerator opening-torque table. FIG. 4 is a diagram modeling a vehicle driving force transmission system. FIG. 5 is a control block diagram for realizing the vibration suppression control calculation process. FIG. 6 is a flowchart showing a processing procedure for calculating vehicle body driving force disturbance and driving wheel disturbance. FIG. 7 is a diagram showing a control block for calculating a vehicle body driving force disturbance estimated value based on the motor angular velocity and the final torque target value. FIG. 8 is a flowchart showing a processing procedure for calculating vehicle body driving force disturbance and driving wheel disturbance in the second embodiment. FIG. 9 is a control block diagram for calculating vehicle body driving force disturbance and driving wheel disturbance. FIG. 10 is a block diagram illustrating a detailed configuration of the disturbance estimation calculation processing unit. FIG. 11 is a flowchart showing a processing procedure for calculating vehicle body driving force disturbance and driving wheel disturbance in the third embodiment. FIG. 12 is a control block diagram for calculating vehicle body driving force disturbance and driving wheel disturbance. FIG. 13 is a diagram illustrating a control result by the control device for the electric vehicle according to the first embodiment and a control result by the conventional control device (WO2013 / 157315A).

-First embodiment-
FIG. 1 is a block diagram illustrating a main configuration of an electric vehicle including a control device for an electric vehicle according to the first embodiment. An 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 not only electric cars but also hybrid cars and fuel cell cars. . Further, the electric vehicle may be a vehicle that can control acceleration / deceleration and stop of the vehicle only by operating an accelerator pedal. In this vehicle, the driver depresses the accelerator pedal at the time of acceleration and reduces the amount of depression of the accelerator pedal at the time of deceleration or stop, or sets the depression amount of the accelerator pedal to zero.

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

  The inverter 3 includes, for example, two switching elements (for example, power semiconductor elements such as IGBTs and MOS-FETs) for each phase, and turns on / off the switching elements in accordance with a drive signal, thereby removing from the battery 1. The supplied direct current is converted into alternating current, and 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. . Further, when the vehicle is driven and rotated by the drive wheels 9a and 9b, the kinetic energy of the vehicle is recovered as electric energy by generating a regenerative driving force. 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 10 generates a brake fluid pressure corresponding to the friction braking amount command value.
The friction brake 11 is provided on the left and right drive wheels 9a, 9b, and presses the brake pad against the brake rotor according to the brake fluid pressure to generate a braking force on the vehicle.

G sensor 12 detects an acceleration a _s in the longitudinal direction of the vehicle.

  FIG. 2 is a flowchart showing a flow of processing performed by the motor controller 2.

In step S201, a signal indicating the vehicle state is input. 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 angular velocity ω (rad / of the rotor) s), currents iu, iv, iw of the electric motor 4, DC voltage value Vdc (V) between the battery 1 and the inverter 3, driven wheel friction brake command value Fbf ^* and driving wheel friction brake command value Fbd ^* , vehicle longitudinal acceleration a Enter _s .

  The vehicle speed V (km / h) is acquired by communication from a vehicle speed sensor (not shown) or another controller such as the brake controller 10. Alternatively, the motor angular velocity ωm is multiplied by the tire dynamic radius R, and the vehicle speed v (m / s) is obtained by dividing by the gear ratio of the final gear, and unit conversion is performed by multiplying by 3600/1000 to obtain the vehicle speed V ( km / h).

  The accelerator opening θ (%) is acquired from an accelerator opening sensor (not shown), or is acquired by communication 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 angular speed ω (electrical angle) of the rotor by the number of pole pairs of the electric motor 4 to obtain a motor angular speed ωm (rad / s) that is a mechanical angular speed of the electric motor 4. ) And is obtained by multiplying the obtained motor angular velocity ωm by 60 / (2π). The angular velocity ω (rad / s) of the rotor is obtained by differentiating the rotor phase α.

  The electric currents iu, iv, iw (A) of the electric motor 4 are acquired from the current sensor 7.

  The DC voltage value Vdc (V) is obtained from a power supply voltage value transmitted from a voltage sensor (not shown) provided on a DC power supply line between the battery 1 and the inverter 3 or a battery controller (not shown).

The driven wheel friction brake command value Fbf ^* and the drive wheel friction brake command value Fbd ^* are acquired from the brake controller 10 by communication.

Vehicle longitudinal acceleration a _s is obtained from the G sensor 12. Vehicle longitudinal acceleration a _s defines the code so that the value during acceleration of a flat road is positive.

In step S202, a basic torque target value Tm1 ^* is calculated. Specifically, the basic torque target value Tm1 ^* is calculated by referring to the accelerator opening-torque table shown in FIG. 3 based on the accelerator opening θ and the vehicle speed V input in step S201.

  In step S203, disturbance calculation processing is performed. Specifically, the vehicle body driving force disturbance Fdv and the driving wheel disturbance Fdw are calculated. Details of the calculation processing of the vehicle body driving force disturbance Fdv and the driving wheel disturbance Fdw will be described later.

In step S204, vibration suppression control calculation processing is performed. Specifically, the basic torque target value Tm1 ^* set in step S202, the vehicle body driving force disturbance Fdv and driving wheel disturbance Fdw calculated in step S203, and the motor angular velocity ωm are input, and the drive shaft torque response is input. The final torque target value Tm2 ^* that suppresses drive force transmission system vibration (such as torsional vibration of the drive shaft 8) is calculated without sacrificing. Details of the vibration suppression control calculation process will be described later.

In step S205, the d-axis current target value id ^* and the q-axis current target value iq ^* are obtained based on the final torque target value Tm2 ^* , the motor angular velocity ωm, and the DC voltage value Vdc calculated in step S204. For example, a table that defines the relationship between the torque target value, the motor angular velocity, the DC voltage value, the d-axis current target value, and the q-axis current target value is prepared in advance, and d is referred to by referring to this table. An axis current target value id ^* and a 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 AC 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. In addition, you may make it add the non-interference voltage required in order to cancel the interference voltage between dq orthogonal coordinate axes with respect 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 DC voltage value Vdc. The electric motor 4 can be driven with a desired torque indicated by the final torque target value by opening and closing the switching element of the inverter 3 by the PWM signals tu, tv, and tw thus obtained.

  Hereinafter, details of the disturbance calculation process performed in step S203 of FIG. 2 and the vibration suppression control calculation process performed in step S204 will be described. First, a vehicle model used in both processes will be described.

FIG. 4 is a diagram in which a driving force transmission system of a vehicle is modeled, and an equation of motion of the vehicle is expressed by equations (1) to (6). However, the asterisk ( ^* ) attached to the upper right of the code | symbol in Formula (1)-(3) represents the time differentiation.

In particular, when the backlash characteristic from the electric motor 4 to the drive shaft 8 is modeled in the dead zone, the drive shaft torque Td is expressed by the following equation (7).

Here, each parameter in Formula (1)-(7) is as follows.
J _m : Inertia of electric motor J _w : Inertia of drive wheel (for one axis)
M: Weight of vehicle K _d : Torsional rigidity of drive shaft K _t : Coefficient related to friction between tire and road surface N: Overall gear ratio r: Tire load radius ω _m : Angular speed ω _{w of} electric motor: Angular speed T _{m of} driving wheel : Motor torque T _d : Drive shaft torque F: Drive force (for two axes)
F _dv : Vehicle driving force disturbance F _dw : Driving wheel disturbance (for two axes)
V: Vehicle speed θ: Torsion angle θ of drive shaft _d : Overall backlash amount from electric motor to drive shaft

Expressions (1) to (6) are subjected to Laplace conversion, and the transmission characteristics from the motor torque Tm, the vehicle body driving force disturbance Fdv, and the driving wheel disturbance Fdw to the motor angular velocity ωm are obtained as the following expression (8).

However, G _p in the formula (8) (s), G pFdv (s), G pFdw (s) are respectively expressed by the following equation (9) to (11).

Each parameter in the equations (9) to (11) is expressed by the following equations (12) to (21).

  Next, details of the vibration suppression control calculation process performed in step S204 of FIG. 2 will be described.

  FIG. 5 is a control block diagram for realizing the vibration suppression control calculation process. The vibration suppression control calculation process is performed by a feedforward compensator 501 (hereinafter referred to as F / F compensator 501), a feedback compensator 502 (hereinafter referred to as F / B compensator 502), and an adder 503. Is called.

The F / F compensator 501 includes a vehicle model 503 configured by a dead zone model that simulates vehicle parameters and gear backlash, a torsional angular velocity F / B model 504, and a control system delay element 505, and has a basic torque target. A value Tm1 ^* and a disturbance acting on the vehicle are input, and a first torque target value is calculated by feedforward calculation.

The torsional angular velocity F / B model 504 calculates a value obtained by multiplying the previous calculated value of the pseudo drive shaft torsional angular velocity ωd ^ calculated by the vehicle model 503 by the F / B gain K _FBI from the basic torque target value Tm1 ^*. The value obtained by the subtraction is set as the first torque target value. The F / B gain K _FBI is set to a value that satisfies the damping performance.

The control system delay element 505 calculates the motor torque response target value Tmr ^* in consideration of the motor response delay Ga (s) in the first torque target value output from the torsional angular velocity F / B model 504. The motor response delay Ga (s) is expressed by the following equation (22). However, τa is a motor response time constant.

The vehicle model 503 is based on the motor torque response target value Tmr ^* output from the control system delay element 505, the vehicle body driving force disturbance Fdv, and the driving wheel disturbance Fdw. ^ Is calculated. The vehicle model 503 also calculates a pseudo drive shaft torsion angular velocity ωd ^ (ωd ^ = ωm ^ / N-ωw) based on the calculated motor angular speed estimated value ωm ^ and the drive wheel angular speed ωw.

  The F / B compensator 502 calculates a second torque target value based on the deviation between the estimated motor angular velocity value ωm ^ output from the vehicle model 503 and the motor angular velocity ωm (motor angular velocity detection value).

The adder 503 calculates the final torque target value Tm2 ^* by adding the first torque target value and the second torque target value.

  Next, details of the disturbance calculation process performed in step S203 of FIG. 2 will be described. FIG. 6 is a flowchart showing a processing procedure for calculating the vehicle body driving force disturbance Fdv and the driving wheel disturbance Fdw.

In step S601, a vehicle body driving force disturbance estimated value Fdv ^ is calculated based on the motor angular velocity ωm and the final torque target value Tm2 ^* . Here, the friction brake braking amount, road surface gradient resistance, air resistance, and tire rolling resistance are estimated as overall disturbances.

FIG. 7 is a diagram showing a control block for calculating the vehicle body driving force disturbance estimated value Fdv ^ based on the motor angular velocity ωm and the final torque target value Tm2 ^* .

  The control block 701 functions as a filter having a transfer characteristic of H (s) / Gp (s), and performs the filtering process by inputting the motor angular velocity ωm, thereby obtaining the first motor torque estimated value. calculate. H (s) is set so that the order of the denominator of H (s) / Gp (s) is equal to or higher than the order of the numerator. Specifically, since Gp (s) is a third-order / fourth-order filter, here, H (s) is set as a zero-order / first-order low-pass filter. The gain of the low-pass filter is set to a value that optimizes the smoothness and responsiveness of the calculated vehicle body driving force disturbance estimated value Fdv ^.

The control system delay element 702 inputs the final torque target value Tm2 ^* and takes into ^{account the} control calculation time delay e ^−L1s , the sensor signal processing time delay e ^−L2s , and the motor response delay Ga (s) shown in Expression (22). Time delay calculation is performed to calculate a final torque response target value Tm2r ^* .

By the way, the final torque target value Tm2 ^* input to the control system delay element 702 is calculated by a vibration suppression control calculation process performed at a later stage of this process (disturbance calculation process). Therefore, the control system delay element 702 adjusts the delay element in consideration of the fact that the input final torque target value Tm2 ^* is a past value for the control period.

The control block 703 functions as a low-pass filter having a transfer characteristic of H (s), and performs a filtering process by inputting the final torque response target value Tm2r ^* calculated by the control system delay element 702. Then, a second estimated motor torque value is calculated.

  The subtractor 704 calculates a motor torque disturbance estimated value by subtracting the second motor torque estimated value from the first motor torque estimated value.

The control block 705 multiplies the estimated motor torque disturbance value by a gain K _FvTm expressed by the following equation (23) to calculate a vehicle body driving force disturbance estimated value Fdv ^.

  Here, when a vibration of a specific frequency appears in the calculated vehicle body driving force disturbance estimated value Fdv ^, a filtering process such as a notch filter for removing the vibration may be applied to the vehicle body driving force disturbance estimated value Fdv ^.

Returning to FIG. 6, the description will be continued. In step S602, the vehicle body driving force disturbance Fdv is calculated by the following equation (24).

In step S603, the driving wheel disturbance Fdw is calculated from the following equation (25).

As described above, according to the control apparatus for the electric vehicle in the first embodiment, the basic torque target value Tm1 ^* (target torque command value) is set based on the vehicle information, and the torque of the electric motor 4 connected to the drive wheels is controlled. An F / F compensator 501 that inputs a basic torque target value Tm1 ^* and a disturbance acting on the vehicle and calculates a first torque target value by feedforward calculation, and a first torque target And a motor controller 2 for controlling the motor torque according to the value. The F / F compensator 501 is a vehicle model in which characteristics from motor torque and disturbance to drive shaft torsional angular velocity are modeled. The F / F compensator 501 inputs a basic torque target value Tm1 ^* and a disturbance acting on the vehicle, and receives a pseudo drive shaft. The vehicle model 503 that outputs the torsional angular velocity ωd ^ and the pseudo drive shaft torsional angular velocity ωd ^ that is output from the vehicle model 503 are fed back to the basic torque target value Tm1 ^* to thereby calculate the first torque target value. And an F / B model 504. Since the vehicle model 503 calculates the pseudo drive shaft torsion angular velocity ωd ^ in consideration of the disturbance acting on the vehicle, the pseudo drive shaft torsion angular velocity ωd ^ can be obtained with high accuracy even when a disturbance occurs. Thus, drive shaft torsional vibration can be accurately suppressed.

  In the gear backlash section where the drive shaft torque dead zone occurs, the influence of the modeling error due to the disturbance appears prominently in the drive shaft torsion angular velocity. In the apparatus, there was a possibility that the drive shaft torsional vibration could not be accurately suppressed when backlash occurred. However, according to the control apparatus for an electric vehicle in the present embodiment, it is possible to accurately suppress drive shaft torsional vibration even when a gear backlash occurs. Also, in a vehicle that uses a motor as a travel drive source and can control acceleration / deceleration and stop of the vehicle only by operating the accelerator pedal, the motor is compared to a conventional vehicle that uses a brake pedal to decelerate and stop the vehicle. Since the regenerative braking area due to is expanded, the frequency of the traveling scene across the gear backlash section increases. If the vibration suppression control of the present invention is applied to this vehicle, as described above, the drive shaft torsional vibration can be accurately suppressed even when a gear backlash occurs, so that the ride quality can be remarkably improved.

  Further, according to the control device for an electric vehicle in the first embodiment, the disturbance acting on the vehicle is estimated by the motor controller 2, and the estimated disturbance is input to the vehicle model 503. This makes it possible to obtain an accurate disturbance that takes into account changes in the surrounding environment of the vehicle, compared to when the disturbance is a fixed value or when the disturbance is calculated based on relevant parameters. The pseudo drive shaft torsion angular velocity ωd ^ can be obtained well.

  The disturbance estimated by the motor controller 2 includes the braking amount of the friction brake. Therefore, even when the regenerative braking and the friction brake are cooperatively controlled by the electric motor 4 or when the driver performs a braking operation, The drive shaft torsion angular velocity ωd ^ can be obtained with high accuracy, and in particular, the drive shaft torsional vibration can be suppressed with high accuracy even when gear backlash occurs.

  Further, since the disturbance estimated by the motor controller 2 includes the gradient resistance of the road surface, the pseudo drive shaft torsion angular velocity ωd ^ can be obtained with high accuracy even when traveling on a slope, especially when a gear backlash occurs. Drive shaft torsional vibration can be accurately suppressed.

  Furthermore, since the disturbance estimated by the motor controller 2 includes air resistance, the pseudo drive shaft torsion angular velocity ωd ^ can be obtained with high accuracy even under a situation where the air resistance increases, for example, during high-speed traveling. In particular, the drive shaft torsional vibration can be accurately suppressed even when a gear backlash occurs.

  Further, since the disturbance estimated by the motor controller 2 includes the rolling resistance of the tire, the pseudo drive shaft torsion angular velocity ωd ^ can be obtained with high accuracy, and particularly when the gear backlash occurs, the drive shaft torsional vibration is also detected. It can be suppressed with high accuracy.

  Since the motor controller 2 estimates the disturbance acting on the vehicle based on the vehicle model Gp (s) that models the characteristics from the torque input to the vehicle to the motor angular velocity, the disturbance acting on the vehicle is accurately detected. Can be estimated. In addition, because disturbance is estimated from existing vehicle signals with reliable reliability, it is not necessary to add a new sensor to detect the disturbance, which can suppress an increase in cost and make the system complicated. This can reduce the possibility of deterioration of electronic reliability.

-Second Embodiment-
In the first embodiment, the friction brake braking amount, road surface gradient resistance, air resistance, and rolling resistance are estimated as overall disturbances. In the control apparatus for an electric vehicle according to the second embodiment, the disturbance is estimated in consideration of the amount of friction brake braking and the gradient resistance of the road surface without considering air resistance and rolling resistance.

  FIG. 8 is a flowchart showing a processing procedure for calculating the vehicle body driving force disturbance Fdv and the driving wheel disturbance Fdw in the second embodiment. FIG. 9 is a control block diagram for calculating the vehicle body driving force disturbance Fdv and the driving wheel disturbance Fdw.

In step S801 of FIG. 8, the driven wheel brake braking is performed based on the following equations (26) to (29) based on the driven wheel friction brake command value Fbf ^* , the drive wheel friction brake command value Fbd ^* , and the vehicle speed V. An amount Fdbf, a driving wheel brake braking amount Fdbd, and a total brake braking amount Fdb are calculated. This process is performed by the friction brake braking amount calculation unit 901 in FIG.

Here, each parameter in the equations (26) to (29) is as follows.
τ _b : Brake response delay time constant L _b : Brake response delay dead time F _bf ^* : Drive wheel friction brake command value (absolute value of braking amount for two wheels)
F _bd ^* : Driving wheel friction brake command value (absolute value of braking amount for two wheels)
F _dbf : Driven wheel brake braking amount (for two wheels)
F _dbd : Driving wheel brake braking amount (for two wheels)
F _db : Total brake braking amount (for four wheels)

Further, sgn (V) is a function that is 1 when the vehicle speed V is positive, -1 when the vehicle speed V is negative, and 0 when the vehicle speed V is negative. Therefore, the driven wheel friction brake command value F _bf ^* and the drive wheel friction brake command value F _bd ^* are negative values when the vehicle speed V is positive, and positive values when the vehicle speed V is negative.

In place of the driven wheel friction brake command value Fbf ^* and the drive wheel friction brake command value Fbd ^* , friction brake braking, such as a hydraulic pressure sensor for detecting the brake hydraulic pressure, a stroke sensor for detecting the brake operation amount of the driver, etc. The detected wheel brake braking amount Fdbf, the driving wheel brake braking amount Fdbd, and the total brake braking amount Fdb may be calculated using the detected value related to the amount.

In step S802, the air resistance Fda is calculated from the following equation (30). This processing is performed by the air resistance calculation processing unit 902 in FIG.

  In Expression (30), Kρ is an air resistance calculation proportional constant. However, the air resistance calculation proportional constant Kρ may not be a fixed value, but may be variable according to conditions such as the sign of the vehicle speed V and the temperature. Since the air resistance acts in the reverse direction of the vehicle longitudinal direction, the air resistance Fda is set to a negative value when the vehicle speed V is positive, and the air resistance Fda is set to a positive value when the vehicle speed V is negative.

In step S803, the rolling resistance Fdr is calculated from the following equation (31). This process is performed by the rolling resistance calculation processing unit 903 in FIG.

  In Formula (31), Fdrc is a representative value obtained by experimentally determining the rolling resistance in advance. Since the rolling resistance acts in the reverse direction of the vehicle longitudinal direction, the rolling resistance Fdr is set to a negative value when the vehicle speed V is positive, and the rolling resistance Fdr is set to a positive value when the vehicle speed V is negative. Note that the rolling resistance Fdr may be calculated based on a sensor detection value related to a tire pressure sensor or the like.

  In step S804, a vehicle body driving force disturbance estimated value Fdv ^ is calculated. This processing is performed by the disturbance estimation calculation processing unit 904 in FIG.

  FIG. 10 is a block diagram illustrating a detailed configuration of the disturbance estimation calculation processing unit 904. The disturbance estimation calculation processing unit 904 includes a control block 1001, a control system delay element 1002, a control block 1003, an adder 1004, a control system delay element 1005, a control block 1006, a control block 1007, and a control system delay. An element 1008, a control block 1009, a control block 1010, an adder 1011, a subtractor 1012, and a control block 1013 are provided.

  The control block 1001 functions as a filter having a transfer characteristic of H (s) / Gp (s), and performs the filtering process by inputting the motor angular velocity ωm, similarly to the control block 701 in FIG. Thus, the first estimated motor torque value is calculated.

Similarly to the control system delay element 702 in FIG. 7, the control system delay element 1002 inputs the final torque target value Tm2 ^* , and controls control time delay e ^−L1s , sensor signal processing time delay e ^−L2s , Equation (22) The time delay calculation in consideration of the motor response delay Ga (s) shown in FIG.

  Like the control block 703 in FIG. 7, the control block 1003 has a function as a low-pass filter having a transfer characteristic of H (s), and the final torque subjected to the time delay calculation process by the control system delay element 1002. The second motor torque estimated value is calculated by inputting the target value and performing the filtering process.

  The adder 1004 adds the rolling resistance Fdr, the air resistance Fda, and the driven wheel brake braking amount Fdbf to calculate the vehicle body driving force resistance total value.

The control system delay element 1005 receives the vehicle body driving force resistance total value calculated by the adder 1004, and performs a time delay calculation considering the sensor signal processing time delay e- ^L2s .

The control block 1006 inputs the vehicle body driving force resistance combined value that has been subjected to the time delay calculation processing by the control system delay element 1005 to G _pFdv (s) represented by Expression (10), and obtains the motor angular velocity response.

  The control block 1007 functions as a filter having a transfer characteristic of H (s) / Gp (s). The motor angular speed response obtained in the control block 1006 is input to input a third motor torque estimated value. Is calculated.

The control system delay element 1008 receives the driving wheel brake braking amount Fdbd and performs a time delay calculation in consideration of the sensor signal processing time delay e ^−L2s .

The control block 1009 inputs the driving wheel brake braking amount that has been subjected to the time delay calculation process by the control system delay element 1008 to G _pFdw (s) represented by Expression (11), and obtains the motor angular velocity response.

  The control block 1010 functions as a filter having a transfer characteristic of H (s) / Gp (s). The motor angular speed response obtained in the control block 1009 is input to obtain a fourth motor torque estimated value. Is calculated.

  The adder 1011 calculates a fifth motor torque estimated value by adding the third motor torque estimated value and the fourth motor torque estimated value.

  The subtractor 1012 calculates a motor torque disturbance estimated value by subtracting the second motor torque estimated value and the fifth motor torque estimated value from the first motor torque estimated value.

The control block 1013 calculates the vehicle driving force disturbance estimated value Fdv ^ by multiplying the estimated motor torque disturbance value output from the subtractor 1012 by the gain K _FvTm represented by the equation (23).

Returning to the flowchart of FIG. In step S805, the vehicle body driving force disturbance Fdv is calculated from the following equation (32). This processing is performed by the vehicle body driving force disturbance calculation processing unit 905 in FIG.

In step S806, the driving wheel disturbance Fdw is calculated from the following equation (33). This process is performed by the drive wheel disturbance calculation processing unit 906 in FIG.

  As described above, according to the control apparatus for an electric vehicle in the second embodiment, the vehicle model 503 takes into account the disturbance acting on the vehicle in the same manner as the control apparatus for the electric vehicle in the first embodiment. Since the torsional angular velocity ωd ^ is calculated, even if a disturbance occurs, the pseudo drive shaft torsional angular velocity ωd ^ can be obtained with high accuracy, whereby the drive shaft torsional vibration can be suppressed with high accuracy.

Further, based on the driven wheel friction brake command value Fbf ^* and the driving wheel friction brake command value Fbd ^* , the braking amount of the friction brake (the driven wheel brake braking amount Fdbf, the driving wheel brake braking amount Fdbd, and the total brake braking amount Fdb). ) Is calculated. Thereby, compared with the method of calculating | requiring the braking amount of a friction brake using a sensor, the braking amount of a friction brake can be calculated | required stably, without being influenced by the detection error and detection delay of a sensor. In addition, it is not necessary to add a new sensor for detecting the braking amount of the friction brake, so that an increase in cost can be suppressed, and an increase in calculation amount due to the addition of sensor detection signal processing can be suppressed.

  Further, as shown in the equations (26) to (29), the braking amount of the friction brake is considered in consideration of a response delay until the braking force acting on the vehicle changes after the braking amount command value of the friction brake changes. Therefore, the friction brake braking amount can be obtained more accurately.

Instead of the driven wheel friction brake command value Fbf ^* and the driving wheel friction brake command value Fbd ^* , a friction brake amount related value (brake hydraulic pressure, driver brake operation amount, etc.) related to the friction brake braking amount is detected. The braking amount of the friction brake can also be calculated based on the detected value related to the friction braking amount. In this case, the friction brake braking amount that accurately reflects the characteristics and response of the brake actuator can be obtained. In addition, by calculating the braking amount of the friction brake in consideration of the response delay from when the detected value of the friction braking amount related value changes until the braking force acting on the vehicle changes, the friction brake can be calculated more accurately. The amount of braking can be determined.

-Third embodiment-
In the first and second embodiments, the vehicle body driving force disturbance estimated value Fdv ^ is calculated, and then the vehicle body driving force disturbance Fdv and the driving wheel disturbance Fdw are calculated. In the control apparatus for an electric vehicle according to the third embodiment, the vehicle body driving force disturbance Fdv and the driving wheel disturbance Fdw are calculated without calculating the vehicle body driving force disturbance estimated value Fdv ^.

  FIG. 11 is a flowchart showing a processing procedure for calculating the vehicle body driving force disturbance Fdv and the driving wheel disturbance Fdw in the third embodiment. FIG. 12 is a control block diagram for calculating the vehicle body driving force disturbance Fdv and the driving wheel disturbance Fdw.

In step S1101 of FIG. 11, as shown in the following equation (34), a deviation between the differential value and the G sensor 12 thus detected is a vehicle longitudinal acceleration a _s the vehicle speed V, the by multiplying the vehicle weight M, the slope The resistance Fds is calculated. This process is performed by the gradient resistance calculation processing unit 1201 in FIG.

  Here, the vehicle mass M uses the same value as the vehicle mass set in the vehicle model of the vibration suppression control calculation process and the disturbance calculation process. However, when the vehicle mass set in the vehicle model is made variable according to the vehicle mass detection value detected by the suspension stroke sensor or the like, the vehicle mass used for the gradient resistance calculation is also made variable.

  Note that the gradient resistance Fds may be obtained by acquiring the gradient of the road surface by communication or the like from another in-vehicle system such as a car navigation system and multiplying the acquired gradient by the vehicle mass M.

In step S1102, driven wheel brake braking is performed based on equations (26), (27), and (29) based on driven wheel friction brake command value Fbf ^* , driving wheel friction brake command value Fbd ^* , and vehicle speed V. An amount Fdbf and a driving wheel brake braking amount Fdbd are calculated. This process is performed by the friction brake disturbance calculation processing unit 1202 of FIG.

  In step S1103, air resistance Fda is calculated from equation (30). This process is performed by the air resistance calculation processing unit 1203 in FIG.

  In step S1104, the rolling resistance Fdr is calculated from the equation (31). This process is performed by the rolling resistance calculation processing unit 1204 in FIG.

In step S1105, as shown in the following equation (35), the vehicle body driving force disturbance Fdv is calculated by adding the driven wheel brake braking amount Fdbf, the gradient resistance Fds, the air resistance Fda, and the rolling resistance Fdr. . This processing is performed by the vehicle body driving force disturbance calculation processing unit 1205 in FIG.

In step S1106, the driving wheel disturbance Fdw is calculated from the following equation (36). This process is performed by the drive wheel disturbance calculation processing unit 1206 in FIG.

  As described above, according to the control device for an electric vehicle in the third embodiment, the vehicle model 503 takes into account the disturbance acting on the vehicle, similarly to the control device for the electric vehicle in the first and second embodiments. Since the pseudo drive shaft torsional angular velocity ωd ^ is calculated, the pseudo drive shaft torsional angular velocity ωd ^ can be obtained with high accuracy even when a disturbance occurs, and thus the drive shaft torsional vibration can be accurately suppressed.

  FIG. 13 is a diagram illustrating a control result by the control device for the electric vehicle according to the first embodiment and a control result by the conventional control device (WO2013 / 157315A). In FIG. 13, in a situation where the vehicle is traveling in a coordinated control state of the regenerative brake and friction brake of the electric motor 4 on a downhill road, the target is a situation where the driver gently releases the brake pedal and then depresses the accelerator pedal gently. The torque command value, the final torque target value, and the longitudinal acceleration of the vehicle are shown in order from the top. In FIG. 13, a solid line is a control result by the control apparatus of the electric vehicle in 1st Embodiment, and a dotted line is a control result by the conventional control apparatus.

  During the period from time t0 to t2, the driver gently releases the brake pedal that was depressed, and completely releases the brake pedal at time t2. As a result, the basic torque target value gradually increases from a negative value toward 0 from time t0 to time t2, and becomes 0 at time t2.

  The driver gently depresses the accelerator pedal at the same time as releasing the brake pedal at time t2. Thereby, the basic torque target value gradually increases after time t2.

  By the way, since the value of the motor torque changes from negative to positive at times t2 to t4, the gear backlash section is straddled. In the conventional control device, vibration control is performed in consideration of gear backlash, so that the final torque target value is set again from the time the gear is jammed while keeping the final torque target value constant until the gear is jammed. increase.

  When there is no disturbance, 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, the disturbance is applied because the friction brake intervention continues while driving downhill. In the conventional control device, an error occurs between the vehicle model of vibration suppression control that does not consider these disturbances and the actual vehicle state. Therefore, at time t3 to t4, the final target torque value before the gear is jammed. From the relationship of the action of the F / B compensator for vibration suppression control, the acceleration suddenly increases from time t4 to t5.

  On the other hand, according to the control apparatus for an electric vehicle in the first embodiment, since disturbance is taken into consideration as the vehicle model 503 for vibration suppression control, the vehicle model 503 matches the actual vehicle state. Therefore, since the final torque target value rises at the timing when the gear is jammed, a smooth acceleration response without a shock can be obtained from time t4 to t5.

  The present invention is not limited to the embodiment described above.

Claims (12)

In a control device for an electric vehicle that sets a target torque command value based on vehicle information and controls the torque of a motor connected to drive wheels,
Feedforward calculation means for inputting the target torque command value and at least a part of the disturbance acting on the vehicle, and calculating a first torque target value by feedforward calculation;
Motor torque control means for controlling motor torque according to the first torque target value;
With
The feedforward calculation means is a vehicle model that models characteristics from motor torque and disturbance to drive shaft torsional angular velocity, and inputs the target torque command value and at least a part of the disturbance acting on the vehicle. A vehicle model that outputs a drive shaft torsion angular velocity in accordance with the input disturbance, and a drive shaft torsion angular velocity output from the vehicle model is fed back to the target torque command value to thereby provide the first torque target value. A drive shaft torsion angular velocity feedback model for calculating
Control device for electric vehicle. In the control apparatus of the electric vehicle according to claim 1,
Disturbance estimation means for estimating at least part of the disturbance acting on the vehicle is further provided,
The vehicle model is inputted with the disturbance estimated by the disturbance estimating means.
Control device for electric vehicle. In the control apparatus of the electric vehicle according to claim 1 or 2,
The disturbance includes a braking amount of a friction brake.
Control device for electric vehicle. In the control apparatus of the electric vehicle as described in any one of Claims 1-3,
The disturbance includes road surface gradient resistance,
Control device for electric vehicle. In the control apparatus of the electric vehicle as described in any one of Claims 1-4,
The disturbance includes air resistance,
Control device for electric vehicle. In the control apparatus of the electric vehicle as described in any one of Claims 1-5,
The disturbance includes tire rolling resistance,
Control device for electric vehicle. In the control apparatus of the electric vehicle according to claim 2,
The disturbance estimation means estimates at least a part of the disturbance acting on the vehicle based on a vehicle model obtained by modeling characteristics from torque input to the vehicle to a motor angular velocity.
Control device for electric vehicle. In the control apparatus of the electric vehicle according to claim 3,
Detecting means for detecting a friction braking amount related value related to the braking amount of the friction brake;
Braking amount calculating means for calculating the braking amount of the friction brake based on the friction braking amount related value detected by the detecting means;
An electric vehicle control device further comprising: The control apparatus for an electric vehicle according to claim 8,
The braking amount calculating means calculates a braking amount of the friction brake in consideration of a response delay until a braking force acting on the vehicle changes after a detection value of the detecting means changes;
Control device for electric vehicle. In the control apparatus of the electric vehicle according to claim 3,
Further comprising braking amount calculating means for calculating a braking amount of the friction brake based on a braking amount command value of the friction brake;
Control device for electric vehicle. In the control apparatus of the electric vehicle according to claim 10,
The braking amount calculating means calculates the braking amount of the friction brake in consideration of a response delay from when the braking amount command value of the friction brake changes to when the braking force acting on the vehicle changes;
Control device for electric vehicle. In a control method for an electric vehicle that sets a target torque command value based on vehicle information and controls the torque of a motor connected to drive wheels,
Inputting the target torque command value and at least a part of the disturbance acting on the vehicle, and calculating a first torque target value by feedforward calculation;
Controlling the motor torque according to the first torque target value;
With
In the step of calculating the first torque target value, a vehicle model in which characteristics from motor torque and disturbance to drive shaft torsional angular velocity are modeled, the target torque command value and at least a part of the disturbance acting on the vehicle, , The drive shaft torsion angular velocity corresponding to the input disturbance is output, and the output drive shaft torsion angular velocity is fed back to the target torque command value to calculate the first torque target value. ,
Control method of electric vehicle.

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