Control method for electric vehicles, and control device for electric vehicles

Abstract

To provide an electric-vehicular control method and an electric-vehicular control apparatus, which are capable of reliably suppressing vibration caused by an external disturbance while securing the performance of an electric motor.SOLUTION: A control method for an electric vehicle 100 includes: computing a basic torque target value Tm1* representing torque to be output from an electric motor 14 and compensation torque TC for compensating for vibration caused by an external disturbance exerting to the electric vehicle 100; setting a torque margin Tmargin being a variable margin relative to torque (TmaxP,TmaxR) that can be output from the electric motor 14; limiting the basic torque target value Tm1* on the basis of the torque margin Tmargin, thus computing a post-limiting torque target value Tm1-lim*; then computing an eventual torque target value Tmf* on the basis of the post-limiting torque target value Tm1-lim* and the compensation torque TC; and controlling the electric motor 14 in accordance with the eventual torque target value Tmf*.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a drive system vibration control device that suppresses torsional vibrations occurring in the drive system during full-throttle acceleration. This drive system vibration control device is configured to limit the required torque by an upper limit torque set according to the rotational speed of the electric motor. Therefore, during full-throttle acceleration when the required torque is limited to the upper limit torque, the upper limit torque vibrates due to vibrations in the rotational speed of the electric motor, resulting in torsional vibrations in the drive system. For this reason, the drive system vibration control device of Patent Document 1 is configured to suppress torsional vibrations occurring in the drive system during full-throttle acceleration by using a low-pass filter to attenuate the resonant frequency component of torsional vibrations included in the rotational speed of the electric motor and suppressing vibrations in the upper limit torque. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2014-128088 [Overview of the initiative] [Problems that the invention aims to solve]

[0004] Electric vehicles are known that suppress torsional vibrations by superimposing a compensation torque, which suppresses vibrations caused by external disturbances such as torsional vibrations occurring in the vehicle's drivetrain, onto the requested torque corresponding to accelerator operation, etc., using feedback control. In such electric vehicles, a fixed torque margin is set in advance for the torque that the electric motor can output, and the requested torque is sometimes limited so that it does not exceed the torque that the electric motor can output even when the compensation torque is superimposed.

[0005] However, when the compensation torque is greater than the torque margin during full-open acceleration using the electric motor at maximum torque or during strong regenerative control, the torque that the electric motor should output exceeds the torque that the electric motor can output and is limited by the performance limit of the electric motor. That is, if the torque margin is fixedly set, vibrations caused by disturbances may not be sufficiently suppressed during full-open acceleration or strong regenerative control even though the torque margin is set.

[0006] On the other hand, if the torque margin is set to a large value in order to sufficiently suppress torsional vibrations and the like occurring in the vehicle drive system in all driving scenes, the required torque is significantly limited by the torque margin, so the performance of the electric motor cannot be fully utilized. For example, when performing full-open acceleration on a road surface where torsional vibrations and the like in the vehicle drive system hardly occur, the maximum acceleration performance of the electric vehicle is impaired due to the setting of the torque margin.

[0007] An object of the present invention is to provide a control method for an electric vehicle and a control device for an electric vehicle that can accurately suppress vibrations caused by disturbances while making the most of the performance of the electric motor.

Means for Solving the Problem

[0008] A certain aspect of the present invention is a control method for an electric vehicle having an electric motor as a drive source. In this control method for an electric vehicle, a basic torque target value representing the torque that the electric motor should output is calculated based on the vehicle information of the electric vehicle, and a compensation torque for compensating for vibrations caused by disturbances acting on the electric vehicle is calculated based on a rotation parameter, which is a parameter representing the rotation state of the electric motor. Also, The absolute value of the compensation torque is calculated, compensation torque absolute value Based on this, a torque margin, which is a variable margin with respect to the torque that the electric motor can output, is set. Then, by limiting the basic torque target value based on the torque margin, a limited torque target value is calculated. Thereafter, a final torque target value is calculated based on the limited torque target value and the compensation torque, and the electric motor is driven according to the final torque target value. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a control method for an electric vehicle and a control device for an electric vehicle that can accurately suppress vibrations caused by disturbances while making full use of the performance of the electric motor. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is an explanatory diagram showing the schematic configuration of an electric vehicle. [Figure 2] Figure 2 is a flowchart showing the control modes of an electric vehicle. [Figure 3] Figure 3 shows an example of an accelerator opening-torque table. [Figure 4] Figure 4 is an explanatory diagram showing the dynamic model of an electric vehicle. [Figure 5] Figure 5 is a graph showing the relationship between the rotational speed and torque of an electric motor. [Figure 6] Figure 6 is a block diagram showing the configuration for limiting the basic torque target value. [Figure 7] Figure 7 is a graph showing an example of the configuration of the filtering processing unit. [Figure 8] Figure 8 is a block diagram showing the configuration for vibration damping control processing. [Figure 9] Figure 9 is a graph showing an example of a bandpass filter configuration. [Figure 10] Figure 10 is a time chart showing the changes in motor torque and other parameters when driving on a well-maintained road surface. [Figure 11] Figure 11 is a time chart showing the changes in motor torque and other parameters when road surface conditions change. [Figure 12] Figure 12 is a time chart showing the changes in motor torque and other parameters when the road surface condition changes from a smooth road surface to an uneven road surface. [Figure 13] Figure 13 is a block diagram showing the configuration for the basic torque target value limiting process in the second embodiment. [Figure 14]Figure 14 is an explanatory diagram showing the schematic configuration of a 4WD electric vehicle. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings.

[0012] [First Embodiment] Figure 1 is an explanatory diagram showing the schematic configuration of the electric vehicle 100. As shown in Figure 1, the electric vehicle 100 includes a battery 11, a controller 12, an inverter 13, an electric motor 14, a reduction gear 15, a rotation sensor 16, a current sensor 17, a drive shaft 18, and drive wheels 19. An electric vehicle is a vehicle that uses an electric motor as a drive source or braking source. Any vehicle that uses an electric motor as all or part of its drive source or braking source is an electric vehicle. In other words, electric vehicles include not only electric vehicles but also hybrid vehicles and fuel cell vehicles. The electric vehicle 100 in this embodiment is a hybrid vehicle or electric vehicle that uses the electric motor 14 as both a drive source and a braking source.

[0013] The battery 11 supplies power to the electric motor 14. The battery 11 can also be charged by receiving regenerative power from the electric motor 14. The battery 11 is connected to the electric motor 14 via the inverter 13.

[0014] The controller 12 is a control device for the electric vehicle 100 and controls each component of the electric vehicle 100 based on the vehicle information of the electric vehicle 100. For example, the controller 12 generates a PWM (Pulse Width Modulation signal) signal based on the vehicle information. Then, the controller 12 generates a drive signal for the inverter 13 according to the PWM signal. In this way, the controller 12 controls the operation of the electric motor 4 and the operation of the electric motor 14.

[0015] Vehicle information is parameters indicating the operating state or control state of each part constituting the electric vehicle 100. For example, the vehicle speed V [km / h] of the electric vehicle 100, the acceleration Ac [m / s 2 , the accelerator opening (the operation amount of the accelerator) θ [%], the operation amount of the brake [%], the rotor phase α [rad] of the electric motor 4, the three-phase alternating current i u , i v , i w [A], and the DC voltage V dc [V] (not shown) of the battery 11, etc. are the vehicle information of the electric vehicle 100. The controller 12 appropriately acquires these vehicle information based on inputs from sensors such as the rotation sensor 16 and the current sensor 17, and other measuring instruments not shown.

[0016] Also, the controller 12 may acquire other vehicle information through calculations. In this embodiment, the controller 12 calculates the rotational speed ω m [rad / s] (mechanical angular velocity) of the electric motor 14 using the rotor phase α of the electric motor 4. Further, the controller 12 calculates the rotational speed N m of the electric motor 14 by converting the unit of ω m [rpm]. The rotational speed ω m and the rotational speed N m etc. are vehicle information. And the rotor phase α, the rotational speed ω m , and the rotational speed N m etc. are parameters (rotation parameters) representing the rotational state of the electric motor 14 among the vehicle information.

[0017] The controller 12 is composed of one or more computers and is programmed to control each part of the electric vehicle 100 such as the electric motor 4 at a predetermined control cycle. The program that the controller 12 executes to control the electric vehicle 100 or each part of the electric vehicle 100 is the control program of the electric vehicle 100. The control program of the electric vehicle 100 is stored in, for example, a memory or other storage media. Also, the control program of the electric vehicle 100 may be updated in whole or in part via an electric communication line or the like.

[0018] The inverter 13 converts the DC power supplied from the battery 11 into AC power by switching an element on / off in response to a drive signal input from the controller 12, and supplies it to the electric motor 14. In addition, the inverter 13 converts the AC power generated by the electric motor 14 into DC power through regenerative braking and supplies it to the battery 11, thereby charging the battery 11.

[0019] The electric motor 14 is, for example, a three-phase AC synchronous motor, and generates torque as required by the accelerator opening θ, etc., using AC power supplied via the inverter 13. The torque of the electric motor 14 is transmitted to the drive wheels 19 via the reduction gear 15 and drive shaft 18, generating driving force for the electric vehicle 100. In addition, when the electric motor 14 rotates in conjunction with the drive wheels 19, it generates regenerative braking force, recovering the kinetic energy of the electric vehicle 100 as electrical energy.

[0020] The reduction gear 15 controls the rotational speed ω of the electric motor 14. m By reducing the force and transmitting it to the drive shaft 18, a torque proportional to the reduction ratio is generated.

[0021] The rotation sensor 16 detects the rotor phase α of the electric motor 14 and inputs it to the controller 12. The rotation sensor 16 is, for example, a resolver or an encoder.

[0022] The current sensor 17 detects the current flowing through the electric motor 14 and inputs it to the controller 12. In this embodiment, the current sensor 17 detects the three-phase AC current i u ,i v ,i w The current sensor 7 detects the three-phase AC current i. u ,i v ,i w Of these, the current of any two phases may be detected, and the current of the remaining phase may be calculated.

[0023] Figure 2 is a flowchart showing the control modes of the electric vehicle 100. As shown in Figure 2, the controller 12 performs input processing, basic torque target value calculation processing, basic torque target value limiting processing, vibration damping control processing, current target value calculation processing, and current control processing.

[0024] The input processing in step S201 is a process in which the controller 12 receives vehicle information and calculates parameters (vehicle information) to be used in the processing from step S202 onward as needed. In other words, the controller 12 functions as an input processing unit that performs input processing. In this embodiment, the controller 12 receives the three-phase AC current i of the electric motor 14. u ,i v ,i w , and the DC voltage V of battery 11 dc The controller 12 also obtains the accelerator opening θ and rotor phase α, and uses these to determine the rotational speed ω of the electric motor 14. m or rotational speed N m The system calculates the vehicle speed V [km / h] of the electric vehicle 100, etc.

[0025] Specifically, the controller 12 calculates the electric angular velocity ω of the electric motor 14 by differentiating the rotor phase α with respect to time. e The controller 12 then calculates the electrical angular velocity ω e By dividing this by the number of pole pairs of the electric motor 14, the rotational speed ω m The controller calculates the rotation speed ω. m By multiplying by the unit conversion coefficient (60 / 2π), the rotational speed N m The controller 12 calculates the rotation speed ω. m By dividing this by the gear ratio of the final gear of the reduction gear 5, the angular velocity ω of the drive wheel 19 is obtained. w The controller 12 calculates the angular velocity ω of the drive wheel 19. w The vehicle speed V is calculated by multiplying this by the load radius r [m] of the drive wheel 19, and then multiplying this by the unit conversion coefficient (3600 / 1000).

[0026] Alternatively, the vehicle speed V may be obtained directly by communicating with other controllers such as a meter or brake controller, instead of calculating it as described above. Furthermore, if wheel speed sensors are provided on the drive wheels 19, the controller 12 can obtain the vehicle speed V based on the average value of one or more of these wheel speed sensors. In addition, the vehicle speed V can be calculated using the output of a GPS (Global Positioning System) sensor, etc. Furthermore, the vehicle speed V can be estimated using the output of a front and rear acceleration sensor, etc.

[0027] The basic torque target value calculation process in step S202 calculates the basic torque target value T, which is the basic target value of the torque that the electric motor 14 should output. m1 * This is the process of calculating the basic torque target value. In other words, the controller 12 functions as a basic torque target value calculation processing unit that performs the basic torque target value calculation process. m1 * This is determined based on the driver's operation of the electric vehicle 100. Therefore, the basic torque target value T m1 * This is the required torque for the electric motor 14 (electric vehicle 100). In this embodiment, the controller 12 uses the accelerator opening-torque table to set the basic torque target value T m1 * Calculate.

[0028] Figure 3 shows an example of an accelerator opening-torque table. As shown in Figure 3, the accelerator opening-torque table is based on experiments or simulations, etc., and the rotational speed N of the electric motor 14. m And the accelerator opening θ and the basic torque target value T m1 * This is a table that associates the accelerator opening and torque values. The controller 12 can determine the rotational speed N of the electric motor 14 by referring to this accelerator opening-torque table. m and the basic torque target value T according to the accelerator opening θ. m1 * Calculate.

[0029] In step S203 (see Figure 2), the basic torque target value limiting process is performed by the controller 12, which limits the basic torque target value T m1 * This process limits the upper limit, lower limit, or both of these. In other words, the controller 12 sets the basic torque target value T m1 * It functions as a basic torque target value limiting unit 30 (see Figure 6) that limits the torque.

[0030] Specifically, the controller 12 (basic torque target value limiting unit 30) sets a torque margin T for the torque that the electric motor 14 can output. margin Set the basic torque target value T m1 * The torque margin T is calculated from the torque that the electric motor 14 can output. margin The range is limited by subtracting the following. Below, the basic torque target value T is limited by the basic torque target value limiting process. m1 * The torque target value T after limiting m1-lim * That's what they say.

[0031] The torque that the electric motor 14 can output is a characteristic of the electric motor 14, and depends on the rotational speed N of the electric motor 14. m It is determined accordingly. Below, when the electric motor 14 is under power control, the maximum value (upper limit) of the torque that the electric motor 14 can output is defined as the maximum power torque T. maxP This refers to the maximum torque T. maxP This is a positive value. Also, when the electric motor 14 is regeneratively controlled, the minimum value (lower limit) of the torque that the electric motor 14 can output is the maximum regenerative torque T. maxR That is what they say. Maximum regenerative torque T maxR This value is negative and represents the minimum (lower limit) torque that the electric motor 14 can output.

[0032] When the electric motor 14 is under power control, the limited torque target value T m1-lim * The maximum power torque T maxP Torque margin T margin The value obtained by subtracting (T maxP -Tmargin ) It is restricted as follows. When the electric motor 14 is regeneratively controlled, the restricted torque target value T m1-lim * A is the maximum regenerative torque T maxR A plus the torque margin T margin A (T maxR A + T margin A) or more. And in this embodiment, the torque margin T margin A is not a fixed value but a variable value. In particular, the torque margin T margin A is variably set based on the compensation torque T C A calculated in the vibration damping control process of step S204. The controller 12 sets the torque margin T margin A as described above and restricts the basic torque target value T m1 A * A. The specific configuration for this, that is, the configuration of the basic torque target value restriction unit 30, will be described in detail later.

[0033] The vibration damping control process of step S204 is a process of calculating the final torque target value (hereinafter referred to as the final torque target value T m1-lim A * A) for suppressing torsional vibration or the like generated in the vehicle drive system 69 (see FIG. 8) using the restricted torque target value T mf A * A. That is, the controller 12 functions as a vibration damping control unit 60 (see FIG. 8) that performs the vibration damping control process.

[0034] In the vibration damping control process of this embodiment, at least based on the rotation parameter representing the rotation state of the electric motor 14, the vibration generated by the disturbance d acting on the electric vehicle 100 is compensated (reduced or suppressed) by feedback control with respect to the torque output by the electric motor 14 (hereinafter referred to as the motor torque T m A). The parameter used for this compensation by feedback control is the compensation torque T C A, and the compensation torque T C A is also used for the setting of the torque margin T margin A as described above.

[0035] The disturbance d acting on the electric vehicle 100 typically causes torsional vibrations in the vehicle drive system 69, such as torsional vibrations of the drive shaft 18 (hereinafter referred to as the torsional vibrations of the vehicle drive system 69). Therefore, in the vibration damping control process of the present embodiment, the torsional vibrations of the vehicle drive system 69 are compensated. Further, the disturbance d acting on the electric vehicle 100 may include those caused by various factors. In the present embodiment, it is assumed that the disturbance d is mainly a disturbance caused by the road surface condition or its change, such as the unevenness of the road surface. Therefore, for example, in a scene where the electric vehicle 100 travels on an uneven road surface with unevenness, the disturbance d acts on the electric vehicle 100, and in a scene where the electric vehicle 100 travels on a smooth road surface substantially without unevenness, the disturbance d acting on the electric vehicle 100 is small and can be substantially ignored. Therefore, the compensation torque T used in the above feedback control C has a large value, for example, in a scene where the vehicle travels on an uneven road surface, and a small value in a scene where the vehicle travels on a smooth road surface.

[0036] The specific configuration for the controller 12 to perform the vibration damping control process, that is, the configuration of the vibration damping control unit 60, will be described in detail later.

[0037] The current target value calculation process in step S205 is a process in which the controller 12 calculates the target values of the d-axis current i d and the q-axis current i q of the electric motor 14, which are the target values of the d-axis current target value i d * and the q-axis current target value i q * (not shown). Specifically, based on the final torque target value T mf * , the rotational speed ω m , and the DC voltage V dc of the battery 11, the d-axis current target value i d * and the q-axis current target value i q * (hereinafter referred to as the dq-axis current target values i d * , i q * are calculated. In the present embodiment, the controller 12 uses the final torque target value T mf* , rotational speed ω m , and DC voltage V dc And, the target value i of the dq axis current d * ,i q * A dq-axis current table (not shown) is pre-owned to associate the two. Therefore, the controller 12 refers to this dq-axis current table to determine the final torque target value T. mf * , rotational speed ω m , and DC voltage V dc The target value of the dq axis current i d * ,i q * Perform the calculation.

[0038] In step S206, the current control process is performed by the controller 12 using the inverter 13 to control the current of the electric motor 14, thereby achieving the final torque target value T. mf * motor torque T corresponding to m This process generates a signal and drives (including braking) the electric vehicle 100.

[0039] Specifically, the controller 12 first controls the three-phase AC current i of the electric motor 14. u ,i v ,i w Based on the rotor phase α and the d-axis current i, d and q-axis current i q (Hereafter, dq axis current i d ,i q Next, the controller 12 calculates the target value i of the dq axis current. d * ,i q * and dq axis current i d ,i q Based on the deviation, the d-axis voltage command value V d and q-axis voltage command value V q (The following is the dq axis voltage command value V d ,V q The controller 12 calculates the dq axis voltage command value V. d,V q Based on the rotor phase α, the three-phase voltage command value V u ,V v ,V w The controller 12 then calculates the three-phase voltage command value V. u ,V v ,V w and DC voltage V dc Based on this, the duty cycle t of the PWM signal input to each phase u ,t v ,t w The percentage [%] is calculated. The controller 12 controls the operation of the electric motor 14 by opening and closing the switching element of the inverter 13 according to the PWM signal obtained in this way. As a result, the controller 12 sets the final torque target value T mf * The desired motor torque T specified in m Then, the electric vehicle 100 is driven.

[0040] The controller 12 that performs the above current target value calculation process, current control process, or current target value calculation process and current control process sets the final torque target value T mf * An electric motor control unit is configured to control the electric motor 14 accordingly.

[0041] <Vehicle Model> The following describes the vehicle model of the electric vehicle 100. The vibration damping control process is configured according to this vehicle model. The compensation torque T calculated in the vibration damping control process is... C Since this is used, the basic torque target value limiting process is also indirectly configured according to this vehicle model.

[0042] Figure 4 is an explanatory diagram showing the mechanical model of the electric vehicle 100. The parameters shown in Figure 4 are as follows:

[0043] J m : Electric motor inertia J w Inertia of the drive wheels M: Mass of the vehicle KD: Torsional rigidity of the wheel drive system K t : Coefficient relating to the friction between the drive wheels and the road surface N: Overall gear ratio r: Load radius of the drive wheel ω m : Rotation speed of electric motor T m Torque of electric motor TD: Torque of the drive wheels F: Force applied to electric vehicles V: Speed ​​of the electric vehicle (vehicle speed) ω w Angular velocity of the drive wheels

[0044] From the dynamic model of the electric vehicle 100 shown in Figure 4, the following equations of motion (1) to (5) can be derived. Note that the symbol "*" in equations (1) to (3) represents the time derivative.

[0045]

number

[0046] Motor Torque T m From rotation speed ω m Transfer characteristics G p (s) can be determined from the above equations of motion (1) to (5) and is expressed by equation (6) below. The coefficients a1 to a4 and b0 to b3 in equation (6) are expressed by equations (7) to (14).

[0047]

number

[0048] The transfer characteristics G shown in equation (6) above p When we examine the poles and zeros of (s), we find that one pole and one zero are extremely close in value. This means that α and β in equation (15) below are extremely close in value.

[0049]

number

[0050] Therefore, by performing pole zero cancellation, which approximates α=β in equation (15), the transfer characteristic G of the (second-order) / (third-order) form is obtained as shown in equation (16) below. p (s) can be obtained. Note that the transfer characteristic G p By setting the damping coefficient of (s) (not shown) to "1", the motor torque T m From rotation speed ω m Normative transmission characteristics G up to m (s) is obtained.

[0051]

number

[0052] Furthermore, using the coefficients a1' and a3' used in the denominator of equation (16), the natural vibrational angular velocity ω p This can be expressed by the following equation (17). Furthermore, the natural vibration angular velocity ω p The resonant frequency (natural vibration frequency) f is given by the following equation (18). p It can be converted to [this].

[0053]

number

[0054] <Basic Torque Target Value Limiting Process> The following describes in detail the basic torque target value limiting process performed by the controller 12 as the basic torque target value limiting unit 30.

[0055] Figure 5 shows the rotational speed N of the electric motor 14. m and motor torque T m This graph shows the relationship between the motor torque T that the electric motor 14 can output. As shown in Figure 5, the motor torque T that the electric motor 14 can output is shown in Figure 5. m The range depends on the characteristics of the electric motor 14, and the rotational speed N m Determined by the motor torque T that the electric motor 14 can output. mThe maximum value (upper limit) is the maximum force torque T shown by solid lines in the first and second quadrants of Figure 5. maxP Furthermore, the motor torque T that the electric motor 14 can output is also the motor torque T. m The minimum value (lower limit) of the maximum regenerative torque T is shown by solid lines in the third and fourth quadrants of Figure 5. maxR Therefore, the motor torque T m is, rotational speed N m Depending on the situation, the maximum power torque T maxP and maximum regenerative torque T maxR It can be set within the range enclosed by the box. And the motor torque T that the electric motor 14 should output. m When this range is exceeded, the actual output motor torque T m Due to the performance limitations of the electric motor 14, the maximum power torque T maxP or maximum regenerative torque T maxR It is restricted.

[0056] In the control of the electric vehicle 100, the motor torque T that the electric motor 14 should output is m In other words, the required torque for the electric motor 14 (electric vehicle 100) is, as mentioned above, in principle, the basic torque target value T. m1 * It is represented by this. Furthermore, since vibration damping control is performed by feedback control, this basic torque target value T m1 * Later, a compensatory torque T for vibration control was added. C This is superimposed. At this time, the compensating torque T C The superimposed basic torque target value T m1 * However, the maximum power torque T that the electric motor 14 can output in terms of performance. maxP or maximum regenerative torque T maxR If it exceeds the superimposed compensation torque T C Since all or part of it is effectively invalidated, all or part of the vibration damping effect intended by the vibration damping control process cannot be obtained.

[0057] Therefore, the compensating torque T is not limited by the performance limits of the electric motor 14. CTo obtain the vibration damping effect through superposition, the compensating torque T C The superimposed basic torque target value T m1 * However, the maximum power torque T maxP or maximum regenerative torque T maxR The basic torque target value T should not be exceeded. m1 * It is necessary to limit this in advance. For this reason, the controller 12 (basic torque target value limiting unit 30) sets the maximum power torque T that the electric motor 14 can output in terms of performance. maxP or maximum regenerative torque T maxR In contrast, Torque margin T margin Set the basic torque target value T m1 * The limited torque target value T takes a value within the range shown by the dashed line in Figure 5. m1-lim * This is limited in advance. Below, the torque target value T after limitation is defined. m1-lim * The maximum value (upper limit), i.e., the maximum power torque T maxP Torque margin T margin The value obtained by subtracting this is used in the basic torque target value limiting process, and the upper limit torque T UL Similarly, the limited torque target value T m1-lim * The minimum value (lower limit), i.e., the maximum regenerative torque T maxR Torque margin T margin The value obtained by adding this is used in the basic torque target value limiting process, and the lower torque T LL It is said that the upper limit torque T UL and lower limit torque T LL This is collectively referred to as the torque limit.

[0058] Figure 6 is a block diagram showing the configuration for the basic torque target value limiting process. As shown in Figure 6, the basic torque target value limiting unit 30 controls the rotational speed N m , and compensation torque T C Based on this, the basic torque target value T m1 By limiting the torque, the target value T after the limit is reached. m1-lim * Calculate.

[0059] The basic torque target value limiting unit 30 includes a maximum output torque calculation unit 31, a torque margin setting unit 32, a torque limit calculation unit 33, and a torque limiting unit 34.

[0060] The maximum output torque calculation unit 31 calculates the rotational speed N of the electric motor 14. m Based on this, the maximum motor torque T that the electric motor 14 can output is... m The calculation is performed. In this embodiment, the maximum output torque calculation unit 31 calculates the rotational speed N of the electric motor 14. m And, maximum power torque T maxP and maximum regenerative torque T maxR The unit has a pre-existing table that associates the values ​​of the motor and the motor. Therefore, the maximum output torque calculation unit 31 can determine the rotational speed N of the electric motor 14 by referring to this table. m Maximum power torque T corresponding to maxP and maximum regenerative torque T maxR Perform the calculation.

[0061] The torque margin setting unit 32 is a compensating torque T C Based on the previous value, Torque margin T margin The torque margin T is set. In this embodiment, the torque margin setting unit 32 includes an absolute value calculation unit 41, a filtering processing unit 42, an offset torque storage unit 43, and a correction unit 44, and using these, the torque margin T is set. margin Perform the calculation.

[0062] The absolute value calculation unit 41 calculates the compensation torque T C The absolute value of |T C The absolute value | is calculated by the absolute value calculation unit 41. C | represents the compensation torque T over a predetermined period (e.g., 1 control cycle). C This represents the maximum amplitude. In other words, the absolute value calculation unit 41 is essentially the compensated torque T C This is the amplitude calculation unit that calculates the amplitude of [something].

[0063] The filtering processing unit 42 controls the compensation torque T C The absolute value of |T CA filtering process is performed on the | to allow specific frequency components to pass through (and reduce components other than the specific frequency components). Filtered Compensated Torque T C The absolute value of |T C |(Below is the compensation torque after filtering|T C | flt (This refers to the torque margin T) margin This is used in the calculation. In this embodiment, the vibration to be suppressed by the vibration damping control process is torsional vibration in the vehicle drive system 69, so the specific frequency components that the filtering processing unit 42 allows to pass through include the resonant frequency components of the torsional vibration in the vehicle drive system 69. That is, the filtering processing unit 42 allows the resonant frequency components of the torsional vibration in the vehicle drive system 69 to pass through and attenuates all or part of the other frequency components. This results in a torque margin T margin It is set particularly appropriately without being allocated extra.

[0064] Figure 7 is a graph showing an example of the configuration of the filtering processing unit 42. As shown in Figure 7, the filtering processing unit 42 of this embodiment filters, for example, the resonant frequency f of torsional vibration in the vehicle drive system 69. p It is composed of a low-pass filter (LPF) with a cutoff frequency of f. Therefore, the filtering processing unit 42 has a resonant frequency f. p It allows frequency components of this frequency and below to pass through, approximately at the resonant frequency f p It reduces or removes frequency components larger than this. Note that the horizontal axis in Figure 7 is on a logarithmic scale. Also, in Figure 7, the resonant frequency f p It is sufficient that it is included in the passband, and it does not necessarily have to be exactly the same as the cutoff frequency. However, as shown in Figure 7, the resonant frequency f p When the cutoff frequency is set to T, the torque margin T margin This is particularly well-configured.

[0065] The offset torque memory unit 43 (see Figure 6) stores the offset torque T offset Remember the offset torque T. offset Torque margin T marginThis is a predetermined reference value (fixed value) determined by experiment or simulation. In this embodiment, the offset torque T offset Torque margin T margin This is the minimum value (lower limit).

[0066] The correction unit 44 provides the compensation torque |T after filtering. C | flt Using the reference value offset torque T, offset By correcting this, the torque margin T margin The offset torque T is calculated. In this embodiment, the correction unit 44 calculates the offset torque T. offset Compensated torque after filtering |T C | flt By adding this, the torque margin T margin This calculates the torque margin T. margin Compensated torque T C It is set variably according to the conditions. Also, the compensation torque T C When (especially its amplitude) becomes large, the torque margin T margin The compensating torque T increases accordingly. C The smaller the value, the greater the torque margin T. margin It becomes smaller.

[0067] The torque limit calculation unit 33 calculates the maximum motor torque T that the electric motor 14 can output. m Torque margin T margin Using and , the basic torque target value T m1 * The torque limit to be imposed is calculated. In this embodiment, the torque limit calculation unit 33 includes an upper limit torque calculation unit 46 and a lower limit torque calculation unit 47, and the maximum power torque T maxP and maximum regenerative torque T maxR Torque margin T margin Based on this, the upper limit torque T UL and lower limit torque T LL Perform the calculation.

[0068] The upper limit torque calculation unit 46 is composed of a subtractor. That is, the upper limit torque calculation unit 46 calculates the maximum power torque T maxP Torque margin T margin By subtracting this, the upper limit torque T UL Perform the calculation.

[0069] The lower limit torque calculation unit 47 is composed of an adder. That is, the lower limit torque calculation unit 47 calculates the maximum regenerative torque T maxR Torque margin T margin By adding this, the lower limit torque T LL Perform the calculation.

[0070] The torque limiting unit 34 sets the basic torque target value T based on the torque limit calculated by the torque limit calculation unit 33. m1 * By limiting the torque, the target value T after the limit is reached. m1-lim * The following vibration control process calculates the torque target value T after this limitation. m1-lim * This is done based on the following. In this embodiment, the torque limiting unit 34 is based on the basic torque target value T m1 * The upper limit torque T UL and lower limit torque T LL The torque is limited to within this range. Therefore, when accelerating with the accelerator fully open (hereinafter referred to as full-throttle acceleration), etc., when the electric motor 14 generates the maximum power torque, the limited torque target value T m1-lim * The upper limit torque T UL This is the result. Furthermore, in order to generate the maximum regenerative torque with the electric motor 14 (hereinafter referred to as strong regeneration), the limited torque target value T m1-lim * The lower limit torque T LL This is the result.

[0071] <Vibration damping control processing> The vibration control processing performed by the controller 12 as the vibration control unit 60 will be described in detail below.

[0072] Figure 8 is a block diagram showing the configuration for vibration control processing. As shown in Figure 8, the vibration control unit 60 is composed of, for example, a feedforward compensation unit 61, a feedback compensation unit 62, and a final torque target value calculation unit 63. However, it is sufficient for the vibration control unit 60 to include at least the feedback compensation unit 62.

[0073] The feedforward compensation unit 61 sets the limited torque target value T m1-lim * Based on this, a torque target value (hereinafter referred to as the FF-compensated torque target value T) is set to compensate in advance for vibrations occurring in the electric vehicle 100 by feedforward control. m2 * The feedforward compensation unit 61 calculates the motor torque T. m From rotation speed ω m Transfer characteristics G p It is composed of a vibration damping filter using (s). That is, the feedforward compensation unit 61 sets the limited torque target value T m1-lim * By filtering the results, the FF-compensated torque target value T is obtained. m2 * The following is calculated. Specifically, the vibration damping filter constituting the feedforward compensation unit 61 of this embodiment is the normative transmission characteristic G m (s) and transfer characteristics G p (s) Inverse characteristic 1 / G p (s) and, G m (s) / G p (s) is represented by

[0074] The feedback compensation unit 62 sets the final torque target value T. mf * and the rotation speed ω of the electric motor 14 m Based on this, a compensation torque T is superimposed on the torque target value in order to compensate for vibrations occurring in the electric vehicle 100 by feedback control. C The following calculation is performed. The feedback compensation unit 62 of this embodiment includes a disturbance estimation filter 64 and a compensation torque calculation unit 65.

[0075] The disturbance estimation filter 64 calculates the final torque target value T. mf * and the rotation speed ω of the electric motor 14 m Based on this, an estimated value of the disturbance d acting on the electric vehicle 100 (hereinafter referred to as the disturbance estimate d^) is calculated. The disturbance estimation filter 64 is composed of, for example, a rotational speed estimation unit 66, a rotational speed deviation calculation unit 67, and a disturbance estimation unit 68.

[0076] The rotational speed estimation unit 66 calculates the final torque target value T based on the vehicle model of the electric vehicle 100. mf * Using the rotational speed ω m The estimated value of rotational speed ω is an estimated value of m ^ is calculated. In this embodiment, the rotational speed estimation unit 66 calculates the transmission characteristic G p A filter composed of (s), with a final torque target value T mf * By filtering the data, the rotational speed estimate ω m Perform the operation ^.

[0077] The rotational speed deviation calculation unit 67 calculates the rotational speed estimate ω m ^ and the actual rotational speed ω of the electric motor 14 m And, the deviation Δω m The rotational speed deviation calculation unit 67 calculates the rotational speed estimate ω. m ^ from actual rotation speed ω m By subtracting these deviations Δω m Perform the calculation.

[0078] The disturbance estimation unit 68 calculates the deviation Δω m The disturbance estimate d^ is calculated based on the bandpass filter H(s) and the transfer characteristic G p (s) Inverse characteristic 1 / G p (s) is a filter composed of H(s) / G p (s) is represented by

[0079] Figure 9 is a graph showing an example configuration of a bandpass filter H(s). The horizontal axis of Figure 9 is on a logarithmic scale. As shown in Figure 9, the bandpass filter H(s) is configured to control the resonant frequency f of torsional vibration in the vehicle drive system 69. p This is passed through. Therefore, the disturbance estimate d^ is essentially an estimate of the disturbance d that causes torsional vibration in the vehicle drive system 69, and the compensation torque T calculated using this disturbance estimate d^ is C This effectively compensates for torsional vibrations of the vehicle drivetrain 69.

[0080] Furthermore, when the bandpass filter H(s) is constructed using a first-order high-pass filter and a first-order low-pass filter, the bandpass filter H(s) can be expressed by the following equation (19). Also, the time constant τ of the high-pass filter used in equation (19) H and cutoff frequency f HC , and the time constant τ of the low-pass filter L and cutoff frequency f LC This is the resonant frequency f of torsional vibration in a wheel drive system. p Using a predetermined coefficient k, the following equations (20) to (23) express the result.

[0081]

number

[0082] The compensation torque calculation unit 65 (see Figure 8) calculates the compensation torque T based on the disturbance estimate d^. C The calculation is performed. In this embodiment, the compensation torque calculation unit 65 adds a coefficient K predetermined by experiment or simulation to the disturbance estimate d^. FB By multiplying by (gain), a compensatory torque T is created that suppresses or cancels out vibrations caused by disturbance d. C Perform the calculation.

[0083] The final torque target value calculation unit 63 calculates the FF-compensated torque target value T m2 * Compensated torque T C By adding (superimposing) these values, the final torque target value T is obtained.mf * This calculates the final torque target value T, which suppresses torsional vibrations and other vibrations occurring in the vehicle drivetrain 69 through feedforward compensation and feedback compensation. mf * The calculation is performed.

[0084] Then, the controller 12 sets the final torque target value T. mf * The electric motor 14 is controlled to output a final torque target value T. mf * Rotational speed ω for outputting m It rotates, and the final torque target value T mf * Motor torque T corresponding to m (≒T mf * The power ) is input from the electric motor 14 to the vehicle drive system 69. At this time, disturbances d may act on the vehicle drive system 69, but the final torque target value T mf * As described above, the system is set to suppress vibrations caused by disturbance d, so vibrations of the electric vehicle 100 (especially torsional vibrations of the vehicle drive system 69) caused by disturbance d are suppressed. In Figure 8, the actual transmission characteristics of the vehicle drive system 69 are conveniently represented by Gp'(s).

[0085] <effect> In the following, the operation of the electric vehicle 100 according to this embodiment, which is configured as described above, will be explained in comparison with the electric vehicle of the comparative example.

[0086] In the electric vehicle 100 according to this embodiment (hereinafter referred to as "the embodiment"), as described above, the compensating torque T C Variable torque margin T margin This is set. In contrast, in the comparative electric vehicle (hereinafter simply referred to as the comparative example), the torque margin T margin The compensatory torque T is constant (fixed) and can be generated. C A sufficiently large torque margin T margin It is assumed that this is fixedly secured. Torque margin Tmargin Aside from the settings, the comparative electric vehicle is the same as the electric vehicle 100 of this embodiment. For example, the comparative electric vehicle undergoes the same vibration damping control processing as the electric vehicle of this embodiment.

[0087] Figure 10 shows the motor torque T when traveling on a leveled road surface. m This is a time chart showing the changes in the above. More specifically, Figure 10 shows the motor torque T in a driving scenario where full-throttle acceleration starts in a step-like manner at a certain time t1 on a well-maintained road surface. m This shows the changes in the following areas. Here, shortly after the start of full-throttle acceleration, the required torque is the basic torque target value T. m1 * This is the torque limit, the upper torque T. UL The torque reaches its limit and is restricted, and by time t2 at the latest, the restricted torque target value T m1-lim * The upper limit torque T UL It is assumed that these values ​​are equal. Note that the horizontal axis of each time chart shown in Figure 10 represents time [s]. In this example, a level road surface is defined as a road surface that does not substantially generate disturbances d for the electric vehicle 100.

[0088] Figures 10(A) to 10(D) show the motor torque T in the comparative example. m The changes are shown in Figures 10(E) to 10(H), and the motor torque T in the embodiment is shown. m The following changes are shown. Specifically, Figure 10(A) shows the motor torque T in the comparative example. m The changes are shown. Figure 10(B) shows the changes in longitudinal acceleration Ac in the comparative example. Figure 10(C) shows the rotational speed N in the comparative example. m The changes are shown. Figure 10(D) shows the compensation torque T in the comparative example. C The changes are shown. On the other hand, Figure 10(E) shows the motor torque T in the embodiment. m The changes are shown. Figure 10(F) shows the changes in longitudinal acceleration Ac in the embodiment. Figure 10(G) shows the rotational speed N in the embodiment. m The changes are shown. Figure 10(H) shows the compensation torque T in the example. C This shows the trend.

[0089] Furthermore, the motor torque T output by the electric motor 14 m The final torque target value T mf * Since this is equal to the motor torque T output by the electric motor 14 in Figures 10(A) and 10(E), m As a progression, the final torque target value T mf * The change is shown by a solid line. Also, in Figures 10(A) and 10(E), the limited torque target value T m1-lim * The trend is shown by the dashed line.

[0090] As shown in Figures 10(A) and 10(E), when full-throttle acceleration is started at time t1, in both the comparative example and the embodiment, the required torque is the basic torque target value T m1 The upper torque limit T will soon be reached. UL Since it reaches the limit torque target value T m1-lim * The upper limit torque T UL This is the result.

[0091] On the other hand, in this example, since the road surface is a well-maintained road surface, the road surface does not substantially generate any disturbance d for the electric vehicle 100 (vehicle drive system 69). Therefore, as shown in Figures 10(D) and 10(H), the compensating torque T is generated before and after the start of full-throttle acceleration. C It is effectively zero. Therefore, in the embodiment, the set torque margin T margin (=T maxP -T UL ) is the standard value of offset torque T offset Therefore, the possible torque margin T margin It represents the smallest possible state.

[0092] Furthermore, as shown in Figures 10(A) and 10(E), the torque margin T set in the comparative example and the example are as follows: margin Based on the size, the example has a torque margin T compared to the comparative example. margin This is reduced. As a result, the limited torque target value T in the embodiment is reduced.m1-lim * This is the limited torque target value T in the comparative example. m1-lim * It will be higher than that. And the compensating torque T C Since the situation is virtually zero, the final torque target value T in the embodiment mf * This is the final torque target value T in the comparative example. mf * It is higher than the comparative example. In other words, the embodiment achieves a higher final torque target value T than the comparative example. mf * This is the maximum power torque T, which is the performance limit of the electric motor 14. maxP It can be asymptotically approached.

[0093] As a result, as shown in Figures 10(C) and 10(G), the electric motor 14, in this embodiment, has a rotational speed N compared to the comparative example. m It is controlled to increase the value. Then, as shown in Figures 10(B) and 10(F), the maximum value of longitudinal acceleration Ac in the embodiment is higher than the maximum value of longitudinal acceleration Ac in the comparative example.

[0094] In other words, the embodiment has a torque margin T margin Compensating torque T C By setting according to the, a fixed torque margin T margin The performance of the electric motor 14 is utilized more effectively than in the comparative example where the settings were configured differently. This is better suited to the driver's demand for full-throttle acceleration.

[0095] Figure 11 shows the motor torque T when the road surface conditions change. m This is a time chart showing the changes such as the above. More specifically, Figure 11 shows the motor torque T when, after full-throttle acceleration starts at time t1, the road surface changes from a first straightened road surface where driving force is relatively easily transmitted to a second straightened road surface where driving force is relatively difficult to transmit at time t5. m The changes are shown in Figures 11(A) to 11(D) for the motor torque T of the comparative example. m The changes are shown, and Figures 11(E) to 11(H) show the motor torque T of the embodiment.m The changes in these parameters are shown. Furthermore, the parameters shown in Figures 11(A) to 11(H) are the same as those in Figure 10 mentioned above.

[0096] As shown in Figures 11(A) and 11(E), when full-throttle acceleration is started at time t1, in both the comparative example and the embodiment, the required torque is the basic torque target value T m1 The upper torque limit T will soon be reached. UL Since it reaches the limit torque target value T m1-lim * The upper limit torque T UL This is the same as the driving scene in Figure 10.

[0097] On the other hand, in this example, although the road surface is a well-maintained surface, a temporary disturbance d (an impulse-like disturbance) occurs due to a change in the road surface condition at time t5. Therefore, as shown in Figures 11(D) and 11(H), when the road surface condition changes at time t5, the compensating torque T C This fluctuates temporarily. Therefore, as shown in Figures 11(A) and 11(E), in both the comparative example and the embodiment, the torque target value T after limiting is reduced by the vibration damping control process. m1-lim * Compensated torque T C When these are superimposed, the final torque target value T mf * The torque target value T after limiting is m1-lim * It fluctuates beyond that limit.

[0098] In this comparative example, the torque margin T margin (=T maxP -T UL ) is secured in a fixed and sufficiently large manner, so the resulting compensation torque T C The secured torque margin T margin It is within the range. Therefore, as shown in Figure 11(A), in the comparative example, the compensation torque T C The superposition of these factors results in the final torque target value T mf * Even when this fluctuates, this fluctuation affects the final torque target value T.mf * However, the maximum power torque T is the performance limit of the electric motor 14. maxP It will not exceed this. In other words, the maximum power torque T is the performance limit of the electric motor 14. maxP The superimposed compensating torque T C Since not all or part of it is restricted (cut), in the comparative example, torsional vibrations of the vehicle drive system 69 that may occur due to changes in road surface conditions are suppressed.

[0099] In contrast, in this embodiment, the torque margin T margin Compensated torque T C Since it is set variably according to the time t5, the compensation torque T C When this occurs, the torque margin T margin Therefore, as shown in Figure 11(E), in this embodiment, at time t5, the limited torque target value T m1-lim * (= Upper limit torque T) UL ) decreases in a stepwise, steep manner. As a result, at time t5, the final torque target value T in the embodiment is effectively reached. mf * This is the final torque target value T of the comparative example. mf * It decreases sharply to the same extent as [the previous example]. As a result, in the example as well, the compensating torque T C The superposition of these factors results in the final torque target value T mf * Although it fluctuates, the final torque target value T also fluctuates. mf * This is the maximum power torque T, which is the performance limit of the electric motor 14. maxP It can be kept within a range that does not exceed. Therefore, in the embodiment as well, the superimposed compensating torque T C Since not all or part of it is restricted, torsional vibrations of the vehicle drivetrain 69 that may occur due to changes in road surface conditions are suppressed.

[0100] In other words, as shown in Figure 11(F), the embodiment utilizes the performance of the electric motor 14 more effectively than the comparative example until time t5 when a disturbance d occurs due to a change in road surface conditions, after the start of full-throttle acceleration, and achieves higher acceleration that is more suitable for the requirement of full-throttle acceleration than the comparative example. Furthermore, even if a sudden change in road surface conditions (disturbance d) occurs at time t5, the embodiment achieves the same final torque target value T as the comparative example. mf * This is the maximum power torque T, which is the performance limit of the electric motor 14. maxP By keeping the vibration within a range that does not exceed a certain limit, it is possible to suppress torsional vibrations of the vehicle drive system 69 that may occur due to changes in road surface conditions to at least the same level as the comparative example. Therefore, in this embodiment, the performance of the electric motor 14 is utilized more effectively than in the comparative example, and the vibration damping effect is obtained through vibration damping control processing.

[0101] Furthermore, in the comparative example, from time t5 onward, when the road surface conditions change, as shown in Figure 11(B), the longitudinal acceleration Ac decreases to a certain extent from time t5 in accordance with the change in road surface conditions. This is because a constant torque margin T is maintained regardless of road surface conditions, etc. margin Since this is ensured, as shown in Figure 11(A), the limited torque target value T of the comparative example m1-lim * This is because it remains almost constant during full-throttle acceleration.

[0102] In contrast, in this embodiment, the temporary compensation torque T generated at time t5 C As it converges, the longitudinal acceleration Ac gradually recovers (increases), as shown in Figure 11(F). This is due to the torque margin T. margin Compensated torque T C This is because it is variable. Specifically, as shown in Figure 11(E), the compensation torque T C Torque margin T as it converges margin Since it gradually decreases, in this embodiment, the target value of the torque after limiting is T m1-lim * It gradually recovers. Therefore, in this embodiment, the longitudinal acceleration Ac gradually recovers.

[0103] Therefore, comparing the example and the comparative example from time t5 onward, the example has the advantage of being able to accelerate more than the comparative example by utilizing the performance of the electric motor 14.

[0104] In the example, the compensating torque T C After convergence, the limited torque target value T m1-lim * The longitudinal acceleration (Ac) does not recover abruptly, but gradually, which is due to the action of the filtering processing unit 42, which is composed of a low-pass filter. In other words, the torque margin T is increased by the provision of the filtering processing unit 42. margin is the compensating torque T C The offset torque T gradually converges after a delay. offset It converges to. For this reason, in the embodiment, the compensating torque T C After convergence, the limited torque target value T m1-lim * (And consequently, the longitudinal acceleration Ac) gradually recovers.

[0105] Figure 12 shows the motor torque T when the road surface condition changes from a smooth road surface to an uneven road surface. m This is a time chart showing the changes in the motor torque T. More specifically, Figure 12 shows the motor torque T when, after full-throttle acceleration begins at time t1, the road surface changes from a smooth road surface to an uneven road surface that generates a steady disturbance d (in this case, a periodic disturbance d) at time t5. m The changes are shown in Figures 12(A) to 12(D). Figures 12(A) to 12(D) show the motor torque T of the comparative example. m The changes are shown, and Figures 12(E) to 12(H) show the motor torque T of the embodiment. m The changes in these parameters are shown. Furthermore, the parameters shown in Figures 12(A) to 12(H) are the same as those in Figures 10 and 11 mentioned above.

[0106] As shown in Figures 12(A) and 12(E), when full-throttle acceleration is started at time t1, in both the comparative example and the embodiment, the required torque is the basic torque target value T m1 The upper torque limit T will soon be reached. ULSince it reaches the limit torque target value T m1-lim * The upper limit torque T UL This is the same as the driving scenes in Figures 10 and 11.

[0107] On the other hand, in this example, at time t5, the road surface changes from a smooth surface to an uneven surface, causing a periodic disturbance d to occur from time t5 onward. Therefore, as shown in Figures 12(D) and 12(H), a periodic compensating torque T occurs from time t5 onward, when the road surface becomes an uneven surface. C Therefore, as shown in Figures 12(A) and 12(E), in both the comparative example and the embodiment, the torque target value after limitation T is reduced by the vibration damping control process. m1-lim * By superimposing a compensating torque TC, the final torque target value T is achieved. mf * The limited torque target value T m1-lim * It fluctuates periodically, centered around [this point].

[0108] In this comparative example, the torque margin T margin (=T maxP -T UL ) is secured in a fixed and sufficiently large manner, so the resulting compensation torque T C The amplitude is within the secured torque margin T margin It is within the range. Therefore, as shown in Figure 12(A), in the comparative example, the compensation torque T C The superposition of these factors results in the final torque target value T mf * Even when it fluctuates periodically, this periodic fluctuation affects the final torque target value T. mf * However, the maximum power torque T is the performance limit of the electric motor 14. maxP It will not exceed this. In other words, the maximum power torque T is the performance limit of the electric motor 14. maxP The superimposed compensating torque T C Since not all or part of it is restricted (cut), in the comparative example, torsional vibrations of the vehicle drive system 69 that may occur due to changes in road surface conditions are suppressed.

[0109] On the other hand, in the embodiment, the torque margin T margin Compensated torque T C Since it is set variably according to the compensation torque T C When it changes oscillatingly, the torque margin T changes according to its amplitude. margin Therefore, as shown in Figure 12(E), in this embodiment, at time t5, the limited torque target value T increases. m1-lim * (= Upper limit torque T) UL ) decreases in a stepwise, steep manner. As a result, at time t5, the final torque target value T in the embodiment is effectively reached. mf * This is the final torque target value T of the comparative example. mf * It decreases sharply to the same extent as [the previous example]. As a result, in the example as well, the compensating torque T C The superposition of these factors results in the final torque target value T mf * Although it fluctuates periodically, the final torque target value T is also affected by this periodic fluctuation. mf * This is the maximum power torque T, which is the performance limit of the electric motor 14. maxP It can be kept within a range that does not exceed. Therefore, in the embodiment as well, the superimposed compensating torque T C Since not all or part of it is restricted, torsional vibrations of the vehicle drivetrain 69 that may occur due to changes in road surface conditions are suppressed.

[0110] In other words, as shown in Figure 12(F), the embodiment utilizes the performance of the electric motor 14 more effectively than the comparative example until time t5 when disturbance d occurs due to a change in road surface conditions, after the start of full-throttle acceleration, thereby achieving higher acceleration that meets the requirements for full-throttle acceleration than the comparative example. Furthermore, even when a change in road surface conditions (disturbance d) occurs at time t5, the embodiment achieves the same final torque target value T as the comparative example. mf * This is the maximum power torque T, which is the performance limit of the electric motor 14. maxPBy keeping the vibration within a range that does not exceed a certain limit, it is possible to suppress torsional vibrations of the vehicle drive system 69 that may occur due to changes in road surface conditions to at least the same level as the comparative example. Therefore, in this embodiment, the performance of the electric motor 14 is utilized more effectively than in the comparative example, and the vibration damping effect is obtained through vibration damping control processing.

[0111] Although Figures 10 to 12 above show driving scenes with full-throttle acceleration as examples, the same applies to driving scenes with strong regeneration. In other words, the electric vehicle 100 of this embodiment has a basic torque target value T, which is the required torque. m1 Upper limit torque T UL or lower torque T LL In driving scenarios that are restricted by the above, it is possible to utilize the performance of the electric motor 14 while also obtaining vibration damping effects through vibration damping control processing.

[0112] [Second Embodiment] In the first embodiment described above, the torque margin setting unit 32 included in the basic torque target value limiting unit 30 was shown to be composed of an absolute value calculation unit 41, a filtering processing unit 42, an offset torque storage unit 43, and a correction unit 44, but it is not limited to this. Compensated torque T C Torque margin T according to margin This can be set. Below, as a second embodiment, an example of the configuration of the torque margin setting unit 32, which differs from that of the first embodiment, will be described. The configuration other than the torque margin setting unit 32 is the same as that of the first embodiment.

[0113] Figure 13 is a block diagram showing the configuration for the basic torque target value limiting process in the second embodiment. As shown in Figure 13, in this embodiment, the torque margin setting unit 32 is composed of an absolute value calculation unit 201, a first offset torque storage unit 202, a second offset torque storage unit 203, an offset torque selection unit 204, a filtering processing unit 205, and a torque margin selection unit 206.

[0114] The absolute value calculation unit 201 calculates the compensation torque T CThe absolute value of |T C The absolute value | is calculated by the absolute value calculation unit 201. C | represents the compensation torque T over a predetermined period (e.g., 1 control cycle). C This represents the maximum amplitude. In other words, the absolute value calculation unit 201 is essentially the compensated torque T C This is an amplitude calculation unit that calculates the amplitude of the absolute value calculation unit 201. Therefore, the absolute value calculation unit 201 has the same configuration as the absolute value calculation unit 41 in the first embodiment. However, in the first embodiment, the compensated torque T C The absolute value of |T C | remains the same Torque Margin T margin Although it contributes to this, in this embodiment, the compensation torque T C The absolute value of |T C The | is input to the offset torque selection unit 204. Then, the compensation torque T C The absolute value of |T C | is the torque margin T margin The first offset torque T contributes to this. O1 Or second offset torque T O2 It is used for selection.

[0115] The first offset torque storage unit 202 stores the first offset torque T O1 It stores the second offset torque T. O2 It is stored in memory. First offset torque T O1 and 2nd offset torque T O2 In all cases, the torque margin T margin This is a predetermined reference value (fixed value) determined by experiment or simulation, etc. In this embodiment, the first offset torque T O1 The second offset torque T O2 It is set to a value greater than . Therefore, the first offset torque T O1 This refers to the compensatory torque T that may occur when driving on road surfaces that are prone to disturbances d and resulting vibrations, such as uneven road surfaces. C It represents the degree of. Also, the second offset torque T O2This refers to the compensatory torque T that may occur when driving on a road surface that is relatively less prone to external disturbances d and resulting vibrations, such as a well-maintained road surface. C It expresses the degree of something.

[0116] The offset torque selection unit 204 is a compensating torque T C The absolute value of |T C Based on |, the first offset torque T O1 Or second offset torque T O2 It selectively outputs one of the following. Specifically, the offset torque selection unit 204 outputs the compensation torque T C The absolute value of |T C The | is compared with a predetermined value (threshold) not shown in the diagram. Then, the compensation torque T is calculated. C The absolute value of |T C When | is greater than a predetermined value, it is determined that the road surface on which the electric vehicle 100 is traveling is a driving scene that is prone to generating disturbances d and resulting vibrations, and the torque margin T margin The first offset torque T is used as the offset torque for the calculation. O1 Select the first offset torque T. O1 When selected, the second offset torque T O2 Compared to when this is selected, the torque margin T margin It becomes larger. On the other hand, the compensating torque T C The absolute value of |T C When | is below a predetermined value, it is determined that the road surface on which the electric vehicle 100 is traveling is a driving scene that is unlikely to generate disturbances d and vibrations caused by them, and the torque margin T margin The second offset torque T is used as the offset torque in the calculation. O2 Select the second offset torque T. O2 When selected, the first offset torque T O1 Compared to when this is selected, the torque margin T margin The value decreases. The offset torque selected by the offset torque selection unit 204 is output to the filtering processing unit 205 and the torque margin selection unit 206.

[0117] The filtering processing unit 205 performs filtering on the offset torque selected by the offset torque selection unit 204, allowing specific frequency components to pass through (reducing components other than the specific frequency components). O1 When this option is selected, the filtering processing unit 205 calculates the first offset torque (T) after the filtering process. O1-flt ) outputs. Similarly, the offset torque selection unit 204 outputs the second offset torque T O2 When this option is selected, the filtering processing unit 205 calculates the second offset torque (T) after the filtering process. O2-flt The filtering processing unit 205 is configured with a low-pass filter, similar to the filtering processing unit 42 (see Figure 7) in the first embodiment.

[0118] The torque margin selection unit 206 obtains the offset torque selected by the offset torque selection unit 204 and the filtered offset torque output by the filtering processing unit 205, and sets the larger of these two values ​​as the torque margin T margin Output as (select high).

[0119] Specifically, the offset torque selection unit 204 is the first offset torque T O1 If selected, the torque margin selection unit 206 will set the first offset torque T O1 And the first offset torque (T) after filtering O1-flt ) and are compared, and the larger of these is the torque margin T margin Set to the second offset torque T. O2 If selected, the torque margin selection unit 206 will set the second offset torque T O2 And the second offset torque (T) after filtering O2-flt ) and are compared, and the larger of these is the torque margin T margin Set to this.

[0120] Thus, the torque margin T is determined by the select high of the offset torque selected by the offset torque selection unit 204 and the offset torque after filtering output by the filtering processing unit 205. margin When this is set, the offset torque selected by the offset torque selection unit 204 will be the first offset torque T with the larger value. O1 Therefore, the second offset torque T has a small value. O2 When this changes, the torque margin T is quickly followed. margin The switch is abrupt. On the other hand, conversely, the offset torque selected by the offset torque selection unit 204 is the second offset torque T, which has a smaller value. O2 Therefore, the first offset torque T has a large value. O1 When it changes, the torque margin T slowly follows this change. margin The switch is gradual. As a result, the torque margin T margin However, in effect, the first offset torque T O1 Or second offset torque T O2 Even when selected from two values, the upper limit torque T is set substantially the same as in the first embodiment. UL or lower torque T LL It changes.

[0121] As described above, even when the torque margin setting unit 32 is configured, the electric vehicle 100 will have the same effects as in the first embodiment. In this embodiment, the torque margin T margin However, in effect, the first offset torque T O1 Or second offset torque T O2 The torque margin setting unit 32 is selected from two values, but the torque margin T margin It may be configured to selectively set from three or more predetermined offset torques.

[0122] [First variation] In the first and second embodiments described above, a so-called 2WD (two-wheel drive) electric vehicle 100 was used as an example. However, the control method and control device of the electric vehicle 100 in the first and second embodiments are also suitable for 4WD (four-wheel drive) electric vehicles. Below, as a first modification example, a configuration example of a 4WD electric vehicle 300 will be described.

[0123] Figure 14 is an explanatory diagram showing the schematic configuration of a 4WD electric vehicle 300. As shown in Figure 14, the electric vehicle 300 includes a battery 11, a controller 12, and a front drive system S f , and rear drive system S r It is equipped with. Battery 11 is front drive system S f and rear drive system S r It will be used for sharing purposes.

[0124] Front drive system S f This consists of a front inverter 13f, a front motor 14f, a front reduction gear 15f, a front rotation sensor 16f, a front current sensor 17f, a front drive shaft 18f, and a front drive wheel 19f. Each of these parts corresponds to the inverter 13, electric motor 14, reduction gear 15, rotation sensor 16, current sensor 17, drive shaft 18, and drive wheel 19 in the first embodiment.

[0125] Similarly, the rear drive system S r This consists of a rear inverter 13r, a rear motor 14r, a rear reduction gear 15r, a rear rotation sensor 16r, a rear current sensor 17r, a rear drive shaft 18r, and a rear drive wheel 19r. Each of these parts corresponds to the inverter 13, electric motor 14, reduction gear 15, rotation sensor 16, current sensor 17, drive shaft 18, and drive wheel 19 in the first embodiment.

[0126] Therefore, the controller 12 of the electric vehicle 300 controls the DC voltage V of the battery 11. dc The accelerator opening θ is obtained, and the front drive system S fFrom there, the three-phase current i of the front motor 14f f (=i fu ,i fv ,i fw ) and rotor phase α f Similarly, the controller 12 of the electric vehicle 300 controls the rear drive system S. r From there, the three-phase current i of the rear motor 14r r (=i ru ,i rv ,i rw ) and rotor phase α r The controller 12 of the electric vehicle 300 then obtains the front drive system S based on this vehicle information. f and rear drive system S r Control.

[0127] Furthermore, the controller 12 of the electric vehicle 300, as in the first or second embodiment, compensates for the torque T C Torque margin T is set variably according to margin The front drive system S f Basic torque target value T m1f It is configured to limit (not shown). Also, the controller 12 of the electric vehicle 300 is configured, as in the first or second embodiment, to compensate torque T C Torque margin T is set variably according to margin The rear drive system S r Basic torque target value T m1r It is configured to limit (not shown). As a result, the 4WD electric vehicle 300 has the same effects as the first or second embodiment.

[0128] Furthermore, the controller 12 of the electric vehicle 300 is the front drive system S f or rear drive system S r For either one of the following, the compensating torque T C Torque margin T is set variably according to margin The rear drive system S r It may be configured to limit the basic torque target value for [the specified value].

[0129] [Second variation] As described in the first embodiment, the second embodiment, and the first modification above, the torque margin T margin Whether or not it needs to be changed depends on the compensation torque T C The basic torque target value T m1 * (or FF-compensated torque target value T) m2 * By superimposing it on the final torque target value T mf * However, the torque (T) that the electric motor 14 can output is maxP ,T maxR It is determined by whether or not it exceeds the torque margin T. More specifically, margin Whether or not a change is necessary depends on the predetermined offset torque T offset (or T O1 ,T O2 ), and the torque (T) that the predetermined electric motor 14 can output. maxP ,T maxR ) and the real-time generated compensation torque T C It is determined by the relationship between and .

[0130] In this regard, in the second embodiment described above, the compensating torque T C The absolute value of |T C | to, the first offset torque T O1 and 2nd offset torque T O2 By using this for the switching determination, the final torque target value T mf * However, the torque (T) that the electric motor 14 can output is maxP ,T maxR Whether or not it exceeds the torque margin T margin A determination is made as to whether or not it is necessary to change the compensation torque T. However, in the first embodiment described above, a determination is made as to whether or not it is necessary to change the compensation torque T. C The absolute value of |T C |(amplitude) is torque margin T margin By setting the fluctuation range to this, the torque margin T marginThe determination of whether or not a change is necessary is omitted. Therefore, in the first embodiment as well, the controller 12 determines the torque margin T margin The determination is made regarding whether a change is necessary, and the result of that determination is the torque margin T margin When it is determined that a change is necessary, the torque margin T margin It is also acceptable to change the configuration.

[0131] For example, the controller 12 (basic torque target value limiting unit 30) in the first embodiment, similar to the offset torque selection unit 204 in the second embodiment, compensates for the torque T C The absolute value of |T C | is compared with a predetermined value (threshold), and the compensation torque T C The absolute value of |T C When | is greater than a predetermined value, the compensation torque T C The absolute value of |T C | Offset Torque T offset Adding this to the torque margin T margin This can be configured to set up this setting.

[0132] Furthermore, for example, the controller 12 (basic torque target value limiting unit 30) in the first embodiment sets the basic torque target value T m1 * and compensatory torque T C (or its absolute value |T) C Add the sum of the sum (T m1 * +T C ) is the torque (T) that the electric motor 14 can output. maxP ,T maxR ) is compared with the added value (T m1 * +T C ) is the torque (T) that the electric motor 14 can output. maxP ,T maxR When it exceeds ), the torque margin T margin A configuration that combines these elements is also acceptable.

[0133] Thus, the torque margin T margin When determining whether a change is necessary, the limit of the electric motor 14 (T maxP ,TmaxR ) enables acceleration / deceleration that takes advantage of its performance, and furthermore, compensated torque T C However, the torque that the electric motor 14 can output (T maxP ,T maxR When the torque margin T is limited by this and there is a risk that the vibration damping effect of the vibration damping control process will be reduced, the torque margin T is appropriately controlled. margin By setting (increasing) this value, the planned vibration damping effect can be obtained through vibration damping control processing.

[0134] Furthermore, as mentioned above, the compensating torque T C The final torque target value T is superimposed by the mf * However, the torque (T) that the electric motor 14 can output is maxP ,T maxR It determines whether or not it exceeds ) and calculates the torque margin T accordingly. margin When setting the torque margin T margin The increase in the final torque target value T mf * The torque (T) that the electric motor 14 can output maxP ,T maxR The amount can exceed ). For example, the offset torque T in the first embodiment. offset The added value to offset torque T offset Compensation torque T for C The absolute value of |T C |Excess portion (|T C |-T offset This can be done. In this case, the electric motor 14 is utilized to its performance limit.

[0135] As described above, the control methods for electric vehicles according to the first embodiment, the second embodiment, and each modified example are control methods for electric vehicles 100 that use an electric motor 14 as a drive source. In this control method for electric vehicles 100, a basic torque target value (T) representing the torque that the electric motor 14 should output is determined based on vehicle information (θ, etc.) of the electric vehicle 100. m1 * ) is calculated, and the rotation parameter (N) is a parameter that represents the rotation state of the electric motor 14. mBased on this, a compensating torque (T) is used to compensate for vibrations caused by disturbances acting on the electric vehicle 100. C The compensation torque (T) is calculated. C Based on this, the torque (T) that the electric motor 14 can output is determined. maxP ,T maxR Torque margin (T) is a variable margin relative to ) margin ) is set. And the torque margin (T margin Based on this, the basic torque target value (T m1 * By limiting the torque, the target value after limitation (T m1-lim * The torque target value after limitation (T) is then calculated. m1-lim * ) and compensating torque (T C Based on this, the final torque target value (T mf * ) is calculated, and this final torque target value (T mf * The electric motor 14 is controlled according to the following.

[0136] Thus, the basic torque target value T m1 * Compensated torque T C In order to perform vibration damping control processing that superimposes the torque margin T margin Set the required torque, which is the basic torque target value T. m1 * When limiting in advance, the compensation torque T C Torque margin T margin By setting this variable, the performance of the electric motor 14 can be maximized, and vibrations caused by external disturbances d can be effectively suppressed.

[0137] In the control methods for electric vehicles according to the first embodiment, the second embodiment, and each modified example described above, specifically, the compensation torque (T C When the torque margin (T) is small, margin ) is set to a small value. This results in the compensation torque T CIn driving scenarios with small speeds, the electric motor 14 can be used to its fullest potential to achieve acceleration (or deceleration), and the compensating torque T C In driving scenarios with significant vibration, the vibration damping effect intended by the vibration damping control process is achieved without compromise. Therefore, according to the control method for electric vehicles of the first embodiment, the second embodiment, and its modified form, the performance of the electric motor 14 can be maximized, and vibrations caused by external disturbances d can be accurately suppressed.

[0138] In the control methods for electric vehicles according to the first embodiment, the second embodiment, and each modified example described above, the compensation torque (T C The compensation torque T compensates for torsional vibrations of the vehicle drivetrain 69. Of the vibrations caused by external disturbances d, torsional vibrations of the vehicle drivetrain 69 are particularly likely to affect the driving feel. For this reason, as described above, the compensation torque T C By compensating for torsional vibrations of the vehicle drivetrain 69, torsional vibrations of the vehicle drivetrain 69, which tend to affect the driving feel, are particularly well suppressed.

[0139] In particular, in the first embodiment and the control method for electric vehicles according to each modified example, the compensation torque (T C For ), the frequency of torsional vibration (f p A filtering process is performed to allow the following frequency components to pass through, and the compensation torque after filtering is (|T C | flt Based on ), the torque margin (T margin The frequency (f) of the torsional vibration is set in this way. p Compensated torque (|T) with filtering that allows frequency components below the specified frequency to pass through. C | flt Torque margin T based on ) margin Setting this will increase the torque margin T required to suppress torsional vibrations. margin This is set. That is, torque margin T margin Even in situations where it is necessary to increase the torque margin T marginThis is kept to the minimum necessary. Therefore, as described above, the compensation torque (|T) after filtering is C | flt Torque margin T based on ) margin By setting this, the performance of the electric motor 14 can be maximized even in scenes where torsional vibrations caused by external disturbances d are suppressed.

[0140] In the control methods for electric vehicles according to the first embodiment, the second embodiment, and each modified example described above, the compensation torque (T C The absolute value of (|T C |) is calculated, and the compensation torque (T C The absolute value of (|T C Based on |), Torque margin (T margin ) is set. In this way, the compensating torque T C The absolute value of |T C Torque margin T based on amplitude margin By setting this, even if disturbances d with different maximum / minimum amplitudes occur, such as impulse-like disturbances d or step-like disturbances d, the final torque target value T will be maintained. mf * However, the torque (T) that the electric motor 14 can output is maxP ,T maxR ) so as not to exceed an appropriate torque margin T margin This is set. In other words, regardless of the specific form of the disturbance d, an appropriate torque margin T is set. margin This makes it easier to set up.

[0141] In particular, in the first embodiment and the control method for electric vehicles according to each modified example, the offset torque (T) is a predetermined reference value. offset ) and compensating torque (T C The absolute value of (|T C The sum of (|) and is the torque margin (T margin ) is set to this. In this way, the offset torque T offset and compensatory torque T C The absolute value of |T C By adding |, the torque margin T margin When this is set, the compensation torque T CEven when it is practically zero, the offset torque T offset Torque margin T margin This ensures that the response (calculation) to step-like disturbances d is delayed, and even if a sudden disturbance d occurs, the vibration damping effect from the vibration damping control process can be obtained quickly and appropriately.

[0142] Furthermore, in the first embodiment and the control method for electric vehicles according to each modified example, the torque margin (T margin ) is a predetermined reference value called offset torque (T offset It is set using and compensated torque (T C ) based on offset torque (T offset By correcting ), the torque margin (T margin ) is corrected. In this way, the torque margin T margin The standard offset torque T offset Set this value and use it as the compensating torque T C The torque margin T is corrected accordingly. margin When this setting is configured, the torque margin T will be adjusted to be particularly appropriate depending on the driving scene. margin This is easily set.

[0143] In the second embodiment described above and the control method for electric vehicles according to each modified example, a predetermined first offset torque (T o1 ) and predetermined, the first offset torque (T o1 The second offset torque (T) is smaller than the value of the second offset torque (T) o2 ) and, from, compensated torque (T C One of them is selected based on ). And the torque margin (T margin ) is the selected first offset torque (T o1 ) or second offset torque (T o2 It is set using ). In this way, the first offset torque T O1 and the second offset torque T O2 The torque margin T is determined by first defining the offset torque selected from these, and then using that offset torque. marginBy setting this, you can easily and quickly determine the appropriate torque margin T according to the driving scene. margin This will be set.

[0144] In particular, in the second embodiment and the control method for electric vehicles according to each modified example, the selected first offset torque (T o1 ) or second offset torque (T o2 ) and the frequency (f) of the torsional vibration occurring in the vehicle drive system 69 p A filtering process is performed to allow frequency components below ) to pass through. Then, the selected first offset torque (T o1 ) or second offset torque (T o2 ) and the first offset torque (T) after filtering. o1-flt ) or second offset torque (T o2-flt ) and are compared, and the larger of the two values ​​is the torque margin (T margin ) is set to this. In this way, the torque margin T is achieved by the select high of the offset torque and the further filtered offset torque. margin When set, the torque margin T margin The value changes rapidly when it increases and slowly when it decreases. Therefore, when a disturbance d occurs, the torque margin T margin In situations where a large torque margin T is required, it can be quickly addressed. Subsequently, a large torque margin T is provided for vibration damping. margin When it is no longer necessary to maintain the torque margin T, gradually reduce the torque margin T margin This reduces torque and prevents torque steps, allowing the electric vehicle 100 to accelerate (or decelerate) smoothly up to near the performance limit of the electric motor 14.

[0145] In the control methods for electric vehicles according to the first embodiment, the second embodiment, and each modified example described above, the limited torque target value (T m1-lim * Using ), the transmission characteristics (G p (s)) Feedforward control suppresses torsion of the vehicle drivetrain 69 Second torque target value (Tm2 * ) is calculated, and then this second torque target value (T m2 * ) and compensating torque (T C Based on this, the final torque target value (T mf * ) is calculated. In this way, the vibration damping control process involves compensation by feedforward control and the compensated torque T C When the compensation is composed of feedback control that feeds back the feedforward control and feedback control, each vibration damping compensation by feedforward control and feedback control is limited to the target torque value T m1-lim * This is done using the torque margin T. margin Torque limiting based on the setting is performed before each vibration damping compensation by feedforward control and feedback control. If torque limiting is performed after vibration damping compensation, all or part of the torque superimposed for that vibration damping compensation may be cut off by the torque limiting, making it difficult to obtain the intended vibration damping effect. Therefore, as described above, the torque margin T is set before each vibration damping compensation by feedforward control and feedback control. margin By setting a torque limit, the torque margin T margin By limiting torque through the settings, the planned vibration damping effect can be more reliably achieved through vibration damping control processing.

[0146] In the control method for an electric vehicle according to the second embodiment described above and the second modified example based on the first embodiment, the final torque target value (T mf * ) is the torque (T) that the electric motor 14 can output. maxP ,T maxR When it exceeds ), the torque margin (T margin ) is changed. That is, the final torque target value T mf * However, it is determined directly or indirectly whether or not the output torque of the electric motor 14 exceeds the final torque target value T. mf * However, when the torque exceeds the output torque of the electric motor 14, the torque margin Tmargin is changed. By configuring in this way, it is easy to achieve acceleration / deceleration that makes use of the performance of the electric motor 14 up to its limit (T maxP , T maxR ). And when the compensation torque T C is limited by the torque (T maxP , T maxR ) that the electric motor 14 can output, and there is a possibility that the vibration damping effect by the vibration damping control process is reduced, the torque margin T margin is set (increased) particularly accurately, and the vibration damping effect expected by the vibration damping control process can be obtained.

[0147] The control device for an electric vehicle according to the first embodiment, the second embodiment, and each modification is a control device (controller 12) for an electric vehicle 100 having an electric motor 14 as a drive source. This control device (controller 12) of the electric vehicle 100 calculates a basic torque target value (T m1 * ) representing the torque that the electric motor 14 should output based on the vehicle information (θ, etc.) of the electric vehicle 100, a basic torque target value calculation unit (S202), a rotation parameter (N m ) which is a parameter representing the rotation state of the electric motor 14, a compensation torque calculation unit 65 that calculates a compensation torque (T C ) for compensating for vibrations caused by external disturbances acting on the electric vehicle 100, a torque margin setting unit 32 that sets a torque margin (T C ) which is a variable margin with respect to the torque (T maxP , T maxR ) that the electric motor 14 can output, a torque limiting unit 34 that calculates a limited torque target value (T margin ) by limiting the basic torque target value (T margin ), and a final torque target value (T m1 <了 * ) based on the limited torque target value (T m1-lim * ) and the compensation torque (T m1-lim * ), and a final torque target value (T[[ID=4{]] C ) is calculated, and based on the limited torque target value (T mf *The final torque target value calculation unit 63 calculates the final torque target value (T mf * The system includes an electric motor control unit (S205, S206) that controls the electric motor 14 according to the following:

[0148] Basic torque target value T m1 * Compensated torque T C In order to perform vibration damping control processing that superimposes the torque margin T margin Set the required torque, which is the basic torque target value T. m1 * If the compensatory torque T is to be limited in advance, the controller 12 is configured as described above, and the compensatory torque T C Torque margin T margin By setting this variable, the performance of the electric motor 14 can be maximized, and vibrations caused by external disturbances d can be effectively suppressed.

[0149] Although embodiments of the present invention have been described above, the configurations described in the above embodiments and each of the modifications represent only a part of the application examples of the present invention and are not intended to limit the technical scope of the present invention. [Explanation of symbols]

[0150] 2: Motor controller, 4: Electric motor, 5: Reducer, 7: Current sensor, 11: Battery, 12: Controller, 13: Inverter, 13f: Front inverter, 13r: Rear inverter, 14: Electric motor, 14f: Front motor, 14r: Rear motor, 15: Reducer, 15f: Front reducer, 15r: Rear reducer, 16: Rotation sensor, 16f: Front rotation sensor, 16r: Rear rotation sensor, 17: Current sensor, 17f: Front current sensor, 17r: Rear current sensor, 18: Drive shaft, 18f: Front drive shaft, 18r: Rear drive shaft, 19: Drive wheel, 19f: Front drive wheel, 19r: Rear drive wheel, 30: Basic torque target value limiting unit, 31: Maximum output torque calculation unit, 32: Torque merge 33: Torque limit calculation unit, 34: Torque limiting unit, 41: Absolute value calculation unit, 42: Filtering processing unit, 43: Offset torque memory unit, 44: Correction unit, 46: Upper limit torque calculation unit, 47: Lower limit torque calculation unit, 60: Vibration damping control unit, 61: Feedforward compensation unit, 62: Feedback compensation unit, 63: Final torque target value calculation unit, 64: Disturbance estimation filter, 65: Compensation torque calculation unit, 66: Rotation speed estimation unit, 67: Rotation speed deviation calculation unit, 68: Disturbance estimation unit, 69: Vehicle drive system, 100: Electric vehicle, 201: Absolute value calculation unit, 202: First offset torque memory unit, 203: Second offset torque memory unit, 204: Offset torque selection unit, 205: Filtering processing unit, 206: Torque margin selection unit, 300: Electric vehicle

Claims

1. A control method for an electric vehicle that uses an electric motor as a drive source, Based on the vehicle information of the electric vehicle, a basic torque target value representing the torque that the electric motor should output is calculated. Based on the rotational parameters, which are parameters representing the rotational state of the electric motor, a compensation torque is calculated to compensate for vibrations caused by disturbances acting on the electric vehicle. The absolute value of the compensation torque is calculated, Based on the absolute value of the compensation torque, a torque margin, which is a variable margin over the torque that the electric motor can output, is set. Based on the torque margin, the limited torque target value is calculated by limiting the basic torque target value. Based on the aforementioned limited torque target value and the compensation torque, the final torque target value is calculated. The electric motor is controlled according to the aforementioned final torque target value. A method for controlling electric vehicles.

2. A control method for an electric vehicle according to claim 1, When the absolute value of the compensation torque is small, the torque margin is set to be small. A method for controlling electric vehicles.

3. A control method for an electric vehicle according to claim 1, The aforementioned compensation torque compensates for torsional vibrations in the vehicle's drivetrain. A method for controlling electric vehicles.

4. A control method for an electric vehicle according to claim 3, A filtering process is performed on the compensation torque to allow frequency components below the frequency of the torsional vibration to pass through. Based on the compensation torque after the filtering process, the torque margin is set. A method for controlling electric vehicles.

5. A control method for an electric vehicle according to claim 1, The torque margin is set to the value obtained by adding the offset torque, which is a predetermined reference value, and the absolute value of the compensation torque. A method for controlling electric vehicles.

6. A control method for an electric vehicle according to claim 1, The torque margin is set using an offset torque, which is a predetermined reference value. The torque margin is corrected by correcting the offset torque based on the compensation torque. A method for controlling electric vehicles.

7. A control method for an electric vehicle according to claim 1, From a predetermined first offset torque and a predetermined second offset torque which is smaller in value than the first offset torque, one of them is selected based on the compensation torque. The torque margin is set using the selected first offset torque or the second offset torque. A method for controlling electric vehicles.

8. A control method for an electric vehicle according to claim 7, A filtering process is performed on the selected first offset torque or the second offset torque to allow frequency components below the frequency of torsional vibrations occurring in the vehicle drivetrain to pass through. The selected first offset torque or the second offset torque is compared with the first offset torque or the second offset torque after the filtering process, and the larger of the two values ​​is set as the torque margin. A method for controlling electric vehicles.

9. A control method for an electric vehicle according to claim 1, Using the aforementioned limited torque target value, a second torque target value is calculated to suppress the torsion of the vehicle drive system by feedforward control based on the transmission characteristics of the vehicle drive system. Based on the second torque target value and the compensation torque, the final torque target value is calculated. A method for controlling electric vehicles.

10. A control method for an electric vehicle according to claim 1, When the final torque target value exceeds the torque that the electric motor can output, the torque margin is changed. A method for controlling electric vehicles.

11. A control device for an electric vehicle that uses an electric motor as a drive source, A basic torque target value calculation unit calculates a basic torque target value representing the torque that the electric motor should output, based on the vehicle information of the electric vehicle. A compensation torque calculation unit calculates a compensation torque to compensate for vibrations caused by disturbances acting on the electric vehicle, based on rotational parameters which are parameters representing the rotational state of the electric motor. A torque margin setting unit calculates the absolute value of the compensation torque and sets a torque margin, which is a variable margin for the torque that the electric motor can output, based on the absolute value of the compensation torque. A torque limiting unit calculates a limited torque target value by limiting the basic torque target value based on the torque margin, A final torque target value calculation unit calculates a final torque target value based on the limited torque target value and the compensation torque, An electric motor control unit that controls the electric motor according to the final torque target value, A control device for electric vehicles, equipped with the following features.

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