Control method for electric vehicle and control device for electric vehicle

Abstract

An electric vehicle 100 has a motor 10 and a connection portion 101 and travels towing a connection vehicle 102, which is another vehicle, through the connection portion 101. At this time, on the basis of a vehicle operation, a first torque target value Tm1 * is calculated that is a basic torque target value indicating a torque to be output by the motor 10. A sixth torque target value T m6 * used as a final torque command is also calculated in such a way that correction processing for suppressing a back-and-forth vibration component occurring in the electric vehicle 100 by the fact that the connection vehicle 102 is connected to the connection portion 101 is performed on the basic torque target value on the basis of the dynamic characteristics of the connection portion 101 to which the connection vehicle 102 is connected. The motor 10 is then controlled on the basis of this final torque command value.

Description

[Technical Field]

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

[0002] JP2003-009566A discloses a control method for suppressing vibrations occurring in an electric vehicle based on the torque transmission characteristics of a power transmission mechanism connected between the output shaft of a motor and the drive wheels. Summary of the Invention

[0003] Vibration damping control according to the torque transmission characteristics of the power transmission mechanism suppresses vibrations caused by, for example, road gradient, gear backlash, and drive shaft torsion.

[0004] On the other hand, electric vehicles may travel while towing other vehicles, etc. When an electric vehicle travels while towing other vehicles, etc., the total weight of the towing electric vehicle and the towed vehicle, etc., becomes the effective vehicle weight of the electric vehicle. Therefore, when an electric vehicle travels while towing other vehicles, the change in vehicle weight that must be taken into consideration becomes a significant change that cannot be ignored.

[0005] Furthermore, because the torque transmission characteristics of the powertrain mechanism are modeled based on the weight of the electric vehicle, conventional vibration damping control may not provide a sufficient vibration damping effect when the actual vehicle weight changes significantly due to towing another vehicle, etc. Furthermore, the torque transmission characteristics of the powertrain mechanism are usually determined by the structure of the powertrain mechanism, etc., and do not reflect whether or not the vehicle is being towed. For this reason, conventional vibration damping control does not provide a sufficient vibration damping effect when the electric vehicle is towing another vehicle, etc. In other words, when the electric vehicle is towing, conventional vibration damping control does not provide a sufficient vibration damping effect, and vibration occurs in the electric vehicle. As a result, when towing, the electric vehicle may not be able to achieve the torque build-up or smooth acceleration required by vehicle operation.

[0006] 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 achieve torque build-up and smooth acceleration as required by vehicle operation, even when the electric vehicle is towing.

[0007] One aspect of the present invention is a control method for an electric vehicle that has a motor as a drive source and a coupling section for coupling other vehicles, and that travels by towing a combination vehicle that is another vehicle coupled to the coupling section. In this control method, a basic torque target value that represents the torque to be output by the motor is calculated based on vehicle operation. Furthermore, a final torque command, which is a final command value for torque, is calculated by applying a correction process to the basic torque target value based on the dynamic characteristics of the coupling section to which the combination vehicle is coupled, to suppress longitudinal vibration components that occur in the electric vehicle due to the combination vehicle being coupled to the coupling section. The motor is then controlled based on this final torque command value. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram showing a schematic configuration of an electric vehicle. [Figure 2] FIG. 2 is a block diagram showing the configuration of the motor controller. [Figure 3] FIG. 3 is a graph showing an example of an accelerator opening-torque table. [Figure 4] FIG. 4 is an explanatory diagram showing a dynamics model of an electric vehicle in which a combination vehicle is coupled to a coupling section. [Figure 5] FIG. 5 is a block diagram showing the configuration of the front-rear vibration suppression unit. [Figure 6] FIG. 6 is a block diagram showing the configuration of the total weight calculation unit. [Figure 7] FIG. 7 is a block diagram showing the configuration of the electric vehicle weight calculation unit. [Figure 8] FIG. 8 is a block diagram showing the configuration of the natural vibration suppression unit. [Figure 9] FIG. 9 is a block diagram showing the configuration of the power transmission mechanism vibration suppressor. [Figure 10]FIG. 10 is a graph showing the transfer characteristic H2(s) used in the disturbance estimation unit. [Figure 11] FIG. 11 is a block diagram showing the configuration of the current command value calculation unit and the current control processing unit. [Figure 12] FIG. 12 is a time chart showing longitudinal acceleration and the like during towing. [Figure 13] FIG. 13 is a time chart showing longitudinal acceleration and the like when the weight of the combined vehicles is large. [Figure 14] FIG. 14 is a block diagram showing a partial configuration of a vibration suppression control unit in the second embodiment. [Figure 15] FIG. 15 is a block diagram showing the configuration of a front-rear vibration suppression unit in the third embodiment. [Figure 16] FIG. 16 is a block diagram showing the configuration of a natural vibration suppression unit in the third embodiment. [Figure 17] FIG. 17 is a flowchart relating to updating of the natural vibration frequency and the like. [Figure 18] FIG. 18 is a time chart showing longitudinal acceleration and the like in a driving scene in which the natural vibration frequency and the like are updated. [Figure 19] FIG. 19 is a time chart showing the longitudinal acceleration and the like after the natural vibration frequency and the like have been updated. [Figure 20] FIG. 20 is a block diagram showing a partial configuration of a vibration suppression control section in a case where compensation for longitudinal vibrations specific to towing and compensation for power transmission mechanism vibrations are performed substantially in an integrated manner. DETAILED DESCRIPTION OF THE INVENTION

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

[0010] First Embodiment FIG. 1 is an explanatory diagram showing a schematic configuration of an electric vehicle 100. The electric vehicle 100 can be coupled to another vehicle or the like and tow it to travel. The other vehicle or the like is, for example, a self-propelled vehicle or a vehicle (trailer) that does not have the self-propelled ability. In this embodiment, the electric vehicle 100 functions as a towing vehicle that tows another vehicle or the like, but the electric vehicle 100 can travel without towing another vehicle or the like. As shown in FIG. 1, the electric vehicle 100 includes a motor 10, a battery 11, an inverter 12, and a motor controller 13.

[0011] The motor 10 is a driving source of the electric vehicle 100. The torque generated by the motor 10 (hereinafter referred to as motor torque T m (not shown) is transmitted to the drive wheels 23 via the reducer 21 and the drive shaft 22. When the motor 10 rotates together with the drive wheels 23, it can generate a regenerative braking force on the drive wheels 23 by so-called regenerative control. In this way, the motor 10 recovers the kinetic energy of the electric vehicle 100 as electrical energy. In this embodiment, the motor 10 is, for example, a three-phase AC synchronous motor. The current i flowing through each phase of the motor 10 is u ,i v ,i w can be detected using a current sensor 24. The rotor phase θ of the motor 10 is detected using a rotation sensor 25 such as a resolver or an encoder. The reducer 21 and the drive shaft 22 constitute a power transmission mechanism (torque transmission system) that transmits power (torque) from the motor 10 to the drive wheels 23.

[0012] The battery 11 supplies power to drive the motor 10 via the inverter 12. The battery 11 can be charged by regenerative power generated in the motor 10 through regenerative control. The battery 11 is a DC power supply. The DC voltage V output by the battery 11 is dc is detected by, for example, the voltage sensor 26 and is obtained directly from the voltage sensor 26 or via a battery controller (not shown).

[0013] The inverter 12 converts DC power supplied from the battery 11 into AC power and supplies the AC power to the motor 10. The inverter 12 also converts AC regenerated power input from the motor 10 through regenerative control into DC power and inputs the DC power to the battery 11. The inverter 12 is composed of a plurality of switching elements (not shown), and converts the DC power from the battery 11 into AC power by turning these switching elements on and off. Similarly, the inverter 12 converts the AC regenerated power input from the motor 10 into DC power by turning the switching elements on and off. Two pairs of switching elements are provided for each phase of the motor 10. The switching elements are, for example, power semiconductor elements such as IGBTs (insulated gate bipolar transistors) and MOS-FETs (metal oxide semiconductor field effect transistors).

[0014] Motor controller 13 generates a PWM signal (pulse width modulation signal) that is a drive signal for inverter 12, based on various vehicle variables that are parameters that represent the control state of electric vehicle 100 or each part that constitutes electric vehicle 100. Motor controller 13 then controls motor 10 by driving inverter 12 with the generated PWM signal.

[0015] In this embodiment, the motor controller 13 uses the rotor phase θ, the current i as vehicle variables. u ,i v ,i w , DC voltage V dc , longitudinal acceleration A L1 , accelerator opening A po , suspension stroke amount ST FL ,ST FR ,ST RL ,ST RR , and traction running signal SW T etc. are obtained or calculated.

[0016] Longitudinal acceleration A L1 is the acceleration in the longitudinal direction (vertical direction) of the electric vehicle 100, and is detected, for example, by an acceleration sensor (not shown).L1 may be acquired from a controller (not shown). po is a parameter that indicates the operation amount of an accelerator provided in the electric vehicle 100, and is detected by a sensor or the like (not shown). po represents the amount of driving force (torque) required for the electric vehicle 100 in response to the vehicle operation.

[0017] Suspension stroke amount ST FL ,ST FR ,ST RL ,ST RR are the stroke amounts of the suspensions provided on the left front wheel, right front wheel, left rear wheel, and right rear wheel of the electric vehicle 100, respectively. FL ,ST FR ,ST RL ,ST RR is detected by a suspension stroke sensor 27 provided on each suspension. In this embodiment, the front wheels of the electric vehicle 100 are driving wheels 23, and the rear wheels are driven wheels.

[0018] Traction signal switch T is a signal output by the towing travel switch 28. The towing travel switch 28 is a control mode changeover switch that is operated by the driver or the like when the electric vehicle 100 hitches another vehicle to the coupling unit 101 (see FIG. 4) and tows it while traveling. The coupling unit 101 is a member that couples another vehicle or the like, and is a towing member such as a trailer hitch. Hereinafter, the other vehicle or the like (towed vehicle or the like) that is coupled to the coupling unit 101 and towed by the electric vehicle 100 will be referred to as the "coupled vehicle 102."

[0019] In this embodiment, the towing signal SW T is a determination criterion for indicating whether the electric vehicle 100 is towing the combination vehicle 102. Specifically, when the electric vehicle 100 is towing the combination vehicle 102, the towing travel signal SW T is set to ON. Then, the motor controller 13 turns on the traction travel signal SW TBased on this, the motor controller 13 determines whether or not the combination vehicle 102 is coupled to the coupling portion 101, i.e., whether or not towing is to be performed. Then, depending on the result of this determination, the motor controller 13 changes the content of the vibration suppression control that suppresses vibrations occurring in the electric vehicle 100.

[0020] 2 is a block diagram showing the configuration of motor controller 13. Motor controller 13 is configured with one or more computers and is programmed to repeatedly execute the processing of each unit described below at a predetermined cycle. Specifically, motor controller 13 includes an input processing unit 31, a first torque target value calculation unit 32 (basic torque target value calculation unit), a vibration suppression control unit 33 (correction processing unit), a current command value calculation unit 34, and a current control processing unit 35.

[0021] The input processing unit 31 executes input processing to acquire or calculate vehicle variables used for various controls and / or calculations executed by the motor controller 13. For example, the input processing unit 31 acquires vehicle variables such as a rotor phase θ, a current i u ,i v , DC voltage V dc , longitudinal acceleration A L1 , accelerator opening A po , suspension stroke amount ST FL ,ST FR ,ST RL ,ST RR , and traction running signal SW T Get.

[0022] The input processing unit 31 differentiates the rotor phase θ (electrical angle) to calculate the rotor angular velocity ω [rad / s] (electrical angular velocity) of the motor 10. The input processing unit 31 divides the rotor angular velocity ω by the number of pole pairs of the motor 10 to calculate the rotational speed ω of the motor 10 (hereinafter referred to as the motor rotational speed) m [rad / s] (mechanical angular velocity). In addition, the input processing unit 31 calculates the motor rotation speed ω m By multiplying this by the unit conversion factor (60 / 2π), the motor rotation speed N m [rpm] may be calculated.

[0023] In this embodiment, the current sensor 24 detects the U-phase current i u and V-phase current i v Therefore, the input processing unit 31 detects the U-phase current i u and V-phase current i v Using this, W-phase current i w Calculate the following.

[0024]

number

[0025] The first torque target value calculation unit 32 calculates the accelerator opening A po and motor rotation speed ω m Based on this, the first torque target value T m1 * The first torque target value T m1 * is a torque target value calculated based on the vehicle operation, and is the torque that the motor 10 should output (motor torque T m ) That is, the first torque target value T m1 * is a basic torque target value (basic torque target value) for generating the driving force required for electric vehicle 100.

[0026] FIG. 3 is a graph showing an example of an accelerator opening-torque table. As shown in FIG. 3, when the accelerator opening A po and motor rotation speed ω m and the first torque target value T m1 * The first torque target value calculation unit 32 calculates the accelerator opening A po and motor rotation speed ω m By referring to this accelerator opening-torque table based on m1 * Calculate the following.

[0027] The vibration suppression control unit 33 (see FIG. 2) controls the first torque target value T m1 * By correcting the sixth torque target value T m6 * The vibration suppression control process is executed to calculate the sixth torque target value T m6 * is used as a final torque command value, which is a final command value for the torque to be output by the motor 10.

[0028] In this embodiment, there are two types of vibrations that occur in the electric vehicle 100. One is a natural vibration that occurs when the electric vehicle 100 travels towing the combination vehicle 102, due to the combination vehicle 102 being coupled to the coupling section 101. This vibration occurs in the longitudinal direction of the electric vehicle 100. Hereinafter, the vibration that occurs in response to changes in acceleration in the longitudinal direction, due to the combination vehicle 102 being coupled to the coupling section 101, will be referred to as longitudinal vibration. The other type of vibration is a vibration that occurs when the motor torque T m This vibration occurs when the power transmission mechanism transmits the torque to the drive wheels 23. This vibration includes, for example, vibration caused by disturbances such as road gradients, and vibration caused by gear backlash and torsion of the drive shaft 22. Hereinafter, the vibration generated in this power transmission mechanism will be referred to as power transmission mechanism vibration.

[0029] In this embodiment, in order to suppress these vibrations, the vibration suppression control unit 33 includes a front-rear vibration suppression unit 36 and a power transmission mechanism vibration suppression unit 37.

[0030] The longitudinal vibration suppression unit 36 executes longitudinal vibration suppression processing. The longitudinal vibration suppression processing is processing for suppressing longitudinal vibration that occurs when the articulated vehicle 102 is towed, based on the dynamic characteristics of the coupling section 101 to which the articulated vehicle 102 is coupled. The dynamic characteristics of the coupling section 101 to which the articulated vehicle 102 is coupled refer to the change over time in the movement of the coupling portion (including the coupling section 101) that occurs when the articulated vehicle 102 is coupled to the coupling section 101. For example, the natural vibration frequency ω t and damping coefficient ζ tis an index or parameter for specifying the change in the connecting portion over time. Therefore, in this embodiment, the change in the connecting portion over time is determined by the natural vibration frequency ω t , damping coefficient ζ t , or natural vibration frequency ω t and the damping coefficient ζ t Both are identified by

[0031] Specifically, the longitudinal vibration suppression unit 36 receives the towing travel signal SW T Based on this, it is determined whether or not the articulated vehicle 102 is connected to the connecting portion 101.

[0032] When the combination vehicle 102 is connected to the connection portion 101, the longitudinal vibration suppression portion 36 sets the first torque target value T m1 * By performing a first vibration damping correction process to reduce or eliminate the longitudinal vibration component, the second torque target value T m2 * (see FIG. 5). The longitudinal vibration suppression unit 36 then calculates the second torque target value T m2 * is used as the third torque target value T m3 * The longitudinal vibration suppression unit 36 performs the first vibration suppression correction process based on the longitudinal acceleration A L1 , and suspension stroke amount ST FL ,ST FR ,ST RL ,ST RR This is based on the following.

[0033] On the other hand, when the combination vehicle 102 is not connected to the connection portion 101, that is, when no longitudinal vibration occurs, the longitudinal vibration suppression portion 36 sets the first torque target value T m1 * This is directly used as the third torque target value T m3 * Output as

[0034] The power transmission mechanism vibration suppression unit 37 determines the third torque target value T m3 *By performing a second vibration damping correction process (power transmission mechanism vibration suppression process) to further suppress the vibration of the power transmission mechanism, the sixth torque target value T m6 * The power transmission mechanism vibration suppressor 37 performs this second vibration suppression correction process based on the motor rotation speed ω m This is based on the following.

[0035] The current command value calculation unit 34 calculates the sixth torque target value T m6 * , motor rotation speed ω m , and DC voltage V dc Based on this, the d-axis current target value i d * and q-axis current target value i q * (Hereinafter, the dq axis current target value i d * ,i q * In addition, the current command value calculation unit 34 calculates the d-axis non-interference voltage V d-dcpl * and q-axis non-interacting voltage V q-dcpl * (Hereinafter, non-interference voltage V d-dcpl * ,V q-dcpl * The current command value calculation unit 34 calculates, for example, the sixth torque target value T m6 * , motor rotation speed ω m , and DC voltage V dc and the dq axis current target value i d * ,i q * and non-interference voltage V d-dcpl * ,V q-dcpl * Therefore, the current command value calculation unit 34 can calculate the sixth torque target value T m6 * , motor rotation speed ω m , and DC voltage V dcThe dq-axis current target value i d * ,i q * and non-interference voltage V d-dcpl * ,V q-dcpl * Calculate the following.

[0036] The current control processing unit 35 calculates the dq-axis current target value i d * ,i q * and non-interference voltage V d-dcpl * ,V q-dcpl * Based on the PWM signal D uu * ,D ul * ,D vu * ,D vl * ,D wu * ,D wl * (See FIG. 11). The current control processing unit 35 calculates the PWM signal D uu * ,D ul * ,D vu * ,D vl * ,D wu * ,D wl * By driving the inverter 12 by m6 * Motor torque T according to m Output the following.

[0037] Among the components of the motor controller 13 configured as above, the vibration suppression control unit 33 and the current control processing unit 35 will now be described in detail.

[0038] [Configuration of vibration control section] First, a dynamic model of the electric vehicle 100 in which the articulated vehicle 102 is connected to the connecting portion 101 and the motor torque Tm from the motor rotation speed ω m Transfer characteristics G p (s) will be explained.

[0039] Fig. 4 is an explanatory diagram showing a dynamics model of an electric vehicle 100 in which an articulated vehicle 102 is coupled to the coupling section 101. According to the dynamics model shown in Fig. 4, the equations of motion of the electric vehicle 100 can be expressed by the following equations (2) to (7). Furthermore, the equations of motion of the electric vehicle 100 in which an articulated vehicle 102 is coupled to the coupling section 101 can be expressed by the following equations (8) to (11).

[0040]

number

[0041] The parameters shown in Figure 4 and the above equation of motion are as follows: "s" is the Laplace operator.

[0042] J m : Motor inertia J w : Drive wheel inertia (per wheel) K d : Torsional rigidity of the drive shaft K t :Coefficients related to tires and road surface N: Overall gear ratio r: tire load radius ω m : Motor rotation speed ω w : Drive wheel rotation speed θ m : Motor angle θ w :Drive wheel angle T m :Motor torque T d : Drive shaft torque F: Driving force (for two wheels) v1: Vehicle speed of electric vehicle v2: Vehicle speed of connected vehicles x1: Distance traveled by electric vehicle x2: Distance traveled by connected vehicles M1: Weight of electric vehicle M2: Weight of combined vehicles C F : Viscosity characteristics (viscosity coefficient) K F : Elastic properties (elastic modulus) F r : Force applied to the connecting part

[0043] Based on equations (2) to (7), the motor torque T m from the motor rotation speed ω m Transfer characteristics G p When (s) is calculated, the following equation (12) is obtained.

[0044]

number

[0045] Each parameter in equation (12) is expressed by the following equation (13): In equation (13), "M" is the total weight of the electric vehicle 100 and the combination vehicle 102 (=M1+M2).

[0046]

number

[0047] The transfer characteristic G shown in equation (12) p By examining the poles and zeros of (s), we can approximate it to the form shown in the following equation (14). One pole and one zero show very close values. This corresponds to the fact that α and β in equation (14) show very close values.

[0048]

number

[0049] Therefore, by canceling the poles and zeros in equation (14) so that α=β is approximated, the (second-order) / (third-order) transfer characteristic G p(s) is obtained. p " is the torque transmitted by the power transmission mechanism. m is the frequency of the natural vibration caused by transmitting the p " is the damping coefficient of the natural vibration generated by this power transmission mechanism.

[0050]

number

[0051] The transfer characteristic G expressed by the above equation (15) p (s) is the vehicle model of the electric vehicle 100. And the damping coefficient ζ p The transfer characteristic G of the reference response with r (s) is expressed by the following equation (16).

[0052]

number

[0053] Furthermore, according to the equations (2) to (6) of the equations of motion of the electric vehicle 100, the motor torque T m Transmission characteristics G from driving force F pF (s) is expressed in the form of the following equation (17).

[0054]

number

[0055] The transfer characteristics from the driving force F(s) of the electric vehicle 100 to the vehicle body speed v2(s) of the combination vehicle 102 are expressed by the following equation (18) using equations (8) to (11), which are the equations of motion of the electric vehicle 100 with the combination vehicle 102 connected to the connecting portion 101.

[0056]

number

[0057] By examining the poles, the transfer characteristic of equation (18) can be approximated to the transfer characteristic of the second-order vibration system as shown in the following equation (19). t " is the natural vibration frequency of the longitudinal vibration that occurs in the electric vehicle 100 when the combination vehicle 102 is coupled at the coupling portion 101. Also, "ζ t " is the damping coefficient of this natural vibration.

[0058]

number

[0059] Based on the above equations of motion and transmission characteristics, the specific configurations of the front-rear vibration suppression unit 36 and power transmission mechanism vibration suppression unit 37 that constitute the vibration suppression control unit 33 will be described in detail below.

[0060] Fig. 5 is a block diagram showing the configuration of the longitudinal vibration suppression unit 36 (see Fig. 2). As shown in Fig. 5, the longitudinal vibration suppression unit 36 includes a total weight calculation unit 41, an electric vehicle weight calculation unit 42, a combined vehicle weight calculation unit 43, an inherent vibration suppression unit 44, and a torque target value switching unit 45.

[0061] The total weight calculation unit 41 calculates the longitudinal acceleration A L1 and the third torque target value T m3 * The total weight M^ is an estimated value for the total weight M, which is the sum of the weight of the electric vehicle 100 (hereinafter referred to as electric vehicle weight M1) and the weight of the combination vehicle 102 (hereinafter referred to as combination vehicle weight M2). The total weight M^ is input to the combination vehicle weight calculation unit 43.

[0062] The electric vehicle weight calculation unit 42 calculates the suspension stroke amount ST FL ,ST FR ,ST RL ,ST RR The electric vehicle weight M1 is input to the combined vehicle weight calculation unit 43 and the natural vibration suppression unit 44.

[0063] The combined vehicle weight calculation unit 43 estimates the combined vehicle weight M2 based on the total weight M^ and the electric vehicle weight M1. In this embodiment, the combined vehicle weight calculation unit 43 calculates the combined vehicle weight M2 by subtracting the electric vehicle weight M1 from the total weight M^. The combined vehicle weight M2 is input to the natural vibration suppression unit 44.

[0064] The natural vibration suppression unit 44 calculates the first torque target value T based on the dynamic characteristics of the coupling unit 101 to which the combination vehicle 102 is coupled. m1 * The natural vibration suppression unit 44 performs a first vibration suppression correction process to suppress (reduce or remove) the longitudinal vibration component of the electric vehicle weight M1, the connected vehicle weight M2, and the viscosity characteristic C F and elastic property K F Based on the above, the dynamic characteristics (transmission characteristics) of the coupling section 101 to which the combination vehicle 102 is coupled are identified. The dynamic characteristics of the coupling section 101 correspond to the inherent longitudinal vibrations that occur in the electric vehicle 100 and the combination vehicle 102.

[0065] Specifically, the natural vibration suppression unit 44 calculates the viscosity characteristic C based on the electric vehicle weight M1 and the combined vehicle weight M2. F and elastic property K F Using this, the first torque target value T m1 * By correcting the second torque target value T m2 * In this way, the natural vibration suppression unit 44 suppresses the longitudinal vibration, which is the natural vibration that occurs in the electric vehicle 100 when towing. The second torque target value T m2 * is input to the torque target value switching unit 45.

[0066] The torque target value switching unit 45 is a towing travel signal SW T Based on the result of this determination, the torque target value switching unit 45 determines whether or not the combination vehicle 102 is connected to the connection portion 101. Then, based on the result of this determination, the torque target value switching unit 45 changes the third torque target value T m3 * The torque target value to be output as the first torque target value Tm1 * and the second torque target value T m2 * Specifically, the towing signal SW T is OFF and it is determined that the combination vehicle 102 is not combined, the torque target value switching unit 45 changes the first torque target value T m1 * This is directly used as the third torque target value T m3 * The towing travel signal SW T is on and it is determined that the combination vehicle 102 is combined, the torque target value switching unit 45 changes the second torque target value T m2 * The third torque target value T m3 * and outputs it to the power transmission mechanism vibration suppression unit 37.

[0067] Fig. 6 is a block diagram showing the configuration of total weight calculation unit 41 (see Fig. 5). As shown in Fig. 6, total weight calculation unit 41 includes a first absolute value calculation unit 51, a second absolute value calculation unit 52, an acceleration difference calculation unit 53, a gain multiplication unit 54, an integration unit 55, a driving force calculation unit 56, and a longitudinal acceleration estimation unit 57.

[0068] The first absolute value calculation unit 51 calculates the longitudinal acceleration A L1 Absolute value of |A L1 Calculate |. Longitudinal acceleration A L Absolute value of |A L1 is input to the acceleration difference calculation unit 53.

[0069] The second absolute value calculation unit 52 calculates the estimated longitudinal acceleration value A L1 ^ Absolute value of |A L1 ^| is calculated. Estimated longitudinal acceleration A L1 ^ is the third torque target value T m3 * The acceleration in the forward / rearward direction is estimated from the third torque target value T m3 * The estimated longitudinal acceleration value A is calculated by the driving force calculation unit 56 and the longitudinal acceleration estimation unit 57 based on the above.L1 ^ Absolute value of |A L1 ^| is input to the acceleration difference calculation unit 53.

[0070] The acceleration difference calculation unit 53 calculates the longitudinal acceleration A L1 Absolute value of |A L1 | and estimated longitudinal acceleration A L1 ^ Absolute value of |A L1 Acceleration difference ΔA of ^| L1 In this embodiment, the acceleration difference ΔA L1 is the estimated longitudinal acceleration A L1 ^ Absolute value of |A L1 ^| to longitudinal acceleration A L1 Absolute value of |A L1 It is calculated by subtracting |.

[0071] The gain multiplication unit 54 calculates the acceleration difference ΔA L1 Weight setting gain K m The corrected total weight ΔM is calculated by multiplying the weight setting gain K m is determined in advance by experiment, simulation, etc. The corrected total weight ΔM represents the time change rate of the total weight M, that is, the amount of change in the total weight M per control period (unit time).

[0072] The integrator 55 calculates the total weight M^ by adding (integrating) the corrected total weight ΔM for each control cycle. Note that the integrator 55 may initialize the total weight M^ based on the shift operation by the driver, etc. For example, the integrator 55 may initialize the total weight M^ based on the shift operation signal S shift Then, the shift operation signal S shift represents a shift operation to the parking range, the integrator 55 initializes the total weight M^. The initial value of the total weight M^ is, for example, the design weight M ini is.

[0073] The driving force calculation unit 56 calculates the third torque target value T m3 * In this embodiment, the driving force F of the electric vehicle 100 is calculated based on the third torque target value T m3 *, the motor torque T m Transmission characteristics G from driving force F pF By applying (s), the driving force F is calculated.

[0074] The longitudinal acceleration estimation unit 57 calculates a longitudinal acceleration estimation value A based on the driving force F calculated by the driving force calculation unit 56 and the total weight M^ (previous value). L1 Specifically, the estimated longitudinal acceleration A L1 ^ is calculated by dividing the driving force F by the total weight M^.

[0075] Fig. 7 is a block diagram showing the configuration of the electric vehicle weight calculation unit 42 (see Fig. 5). As shown in Fig. 7, the electric vehicle weight calculation unit 42 includes a total stroke amount calculation unit 58, a stroke amount change calculation unit 59, a weight change calculation unit 60, and an adder 61.

[0076] The total stroke amount calculation unit 58 calculates the suspension stroke amount ST FL ,ST FR ,ST RL ,ST RR The total stroke amount ΣST of each suspension is calculated by adding these.

[0077] The stroke amount change calculation unit 59 calculates the reference total stroke amount ST ini The suspension stroke change amount ΔST is calculated by subtracting the total stroke amount ΣST from the reference total stroke amount ST. ini is a reference value that is determined in advance by the design of electric vehicle 100.

[0078] The weight change calculation unit 60 calculates the suspension stroke change amount ΔST by the spring constant K ST [N / mm] to calculate the weight change ΔM1 of the electric vehicle 100. ST is determined in advance by the design of the electric vehicle 100 (each suspension).

[0079] The adding unit 61 calculates the design weight M of the electric vehicle 100. iniand the weight change amount ΔM1 to calculate an electric vehicle weight M1, which is an estimated value of the weight of the electric vehicle 100.

[0080] 8 is a block diagram showing the configuration of the natural vibration suppression unit 44 (see FIG. 5). As shown in FIG. 8, the natural vibration suppression unit 44 includes a feature amount calculation unit 62 and a first vibration suppression correction processing unit 63.

[0081] The feature amount calculation unit 62 calculates the feature amount of the longitudinal vibration caused by the combination vehicle 102 being coupled to the combination vehicle 102, and thereby identifies the dynamic characteristics of the combination unit 101 to which the combination vehicle 102 is coupled. Specifically, the feature amount calculation unit 62 calculates the natural vibration frequency ω t and the damping coefficient ζ t As shown in equations (18) and (19), the natural vibration frequency ω t and the damping coefficient ζ t The calculation of the viscosity characteristic C of the connecting part 101 is F and elastic properties K F The coupling part 101 is, for example, a genuine part of the electric vehicle 100. Therefore, in this embodiment, the coupling part 101 is designed to have a viscosity characteristic C F and elastic property K F is known. The natural vibration frequency of the longitudinal vibration ω t and the damping coefficient ζ t is input to the first vibration damping correction processing unit 63.

[0082] The first vibration damping correction processing unit 63 is configured to t and the damping coefficient ζ t Based on this, the first torque target value T m1 * By correcting the second torque target value T m2 * The correction process performed by the first vibration damping correction processor 63 is a first vibration damping correction process that reduces or removes the front-rear vibration component.

[0083] The first vibration suppression correction processing unit 63 is configured by, for example, a band-stop filter having a frequency band (center frequency) for reducing signals and a variable gain in that frequency band. The first vibration suppression correction processing unit 63 sets the frequency band (center frequency) of this band-stop filter to the natural vibration frequency ω of the longitudinal vibration. t In this embodiment, as shown in FIG. 8, the center frequency is set according to the natural vibration frequency ω t The first vibration damping correction processor 63 also sets the gain at the center frequency of this band-stop filter to the damping coefficient ζ t In this embodiment, as shown in FIG. 8, the center frequency (the natural vibration frequency ω t ) is the damping coefficient ζ of the longitudinal vibration. t The smaller the damping coefficient ζ, the smaller the damping coefficient ζ t The smaller the center frequency ω t The gain is set so that the drop in the gain at the point is large. This effectively suppresses longitudinal vibration.

[0084] More specifically, the first vibration suppression correction processing unit 63 is configured, for example, with a notch filter, which is a type of band-stop filter. The transfer characteristic of the notch filter is expressed by the following equation (20). In equation (20), "ω" is the center frequency, and "ζ" is the damping coefficient. Furthermore, "D" is a parameter (hereinafter simply referred to as gain D) that determines the depth of the drop in gain at the center frequency. Therefore, the first vibration suppression correction processing unit 63 sets the center frequency ω of the notch filter to the natural vibration frequency ω of the longitudinal vibration. t Furthermore, the first vibration damping correction processing unit 63 sets the gain D of the notch filter to the damping coefficient ζ of the front-rear vibration. t The attenuation coefficient ζ of the notch filter is related to the width of the frequency band in which the gain is reduced. The attenuation coefficient ζ of the notch filter is determined in advance based on experiments, simulations, etc., and is preferably set to a value of at least 1. When a band-stop filter other than a notch filter is used, the setting is the same as that of the notch filter.

[0085]

number

[0086] 9 is a block diagram showing the configuration of the power transmission mechanism vibration suppression unit 37 (see FIG. 2). As shown in FIG. 9, the power transmission mechanism vibration suppression unit 37 includes a feedforward compensation unit 64, a feedback compensation unit 65, and an adder 66.

[0087] The feedforward compensation unit 64 calculates the third torque target value T m3 * Motor torque T according to m The power transmission mechanism vibration generated by transmitting the power to the drive wheels 23 through the power transmission mechanism is calculated using a transfer characteristic G p That is, the feedforward compensation unit 64 compensates in advance using the third torque target value T m3 * By compensating for the power transmission mechanism vibration component included in m4 * The feedforward compensation unit 64 calculates the transfer characteristic G p (s) and the transfer characteristic of the reference response G r (s) r (s) / G p The fourth torque target value T m4 * is input to the adder 66.

[0088] The feedback compensation unit 65 calculates a sixth torque target value T m6 * (previous value) and the actual motor rotation speed ω m and compensates for power transmission mechanism vibrations caused by disturbances such as road gradients, etc. Specifically, the feedback compensation unit 65 includes a motor rotation speed estimator 71, a deviation calculator 72, a disturbance estimator 73, and a gain multiplier 74.

[0089] The motor rotation speed estimation unit 71 estimates the transfer characteristic G p By using (s), the sixth torque target value T m6 * from the motor rotation speed ω m The estimated motor rotation speed ω m Calculates ^.

[0090] The deviation calculation unit 72 calculates the motor rotation speed ω m and the estimated motor rotation speed ω m ^ deviation (hereinafter referred to as motor rotation speed deviation Δω m In this embodiment, the motor rotation speed deviation Δω m is the estimated motor rotation speed ω m ^ to motor rotation speed ω m It is calculated by subtracting

[0091] The disturbance estimation unit 73 estimates the motor rotation speed deviation Δω m The disturbance estimation unit 73 calculates an estimated disturbance value d^ based on the transfer characteristic H2(s) / G p The difference between the numerator and denominator orders of the transfer characteristic H2(s) is expressed as the transfer characteristic G p The disturbance estimated value d^ is input to a gain multiplication unit 74.

[0092] The gain multiplication unit 74 multiplies the disturbance estimate d^ by a feedback gain K FB The fifth torque target value T m5 * Calculate the feedback gain K FB The fifth torque target value T m5 * is the torque associated with the powertrain vibration caused by the disturbance, i.e., the motor torque T m The fifth torque target value Tm5 * is input to the adder 66.

[0093] The adder 66 calculates a fourth torque target value T m4 * and the fifth torque target value T m5 * The sixth torque target value T m6 * Calculate the sixth torque target value T m6 * As mentioned above, the motor torque T m This is the final command value for

[0094] As described above, the second vibration damping correction process performed by the power transmission mechanism vibration suppression section 37 is made up of the compensation process by the feedforward compensation section 64 and the compensation process by the feedback compensation section 65.

[0095] FIG. 10 is a graph showing the transfer characteristic H2(s) used in the disturbance estimation unit 73. As shown in FIG. 10, the transfer characteristic H2(s) is, for example, a band-pass filter. When the transfer characteristic H2(s) is a band-pass filter, the feedback compensation unit 65 becomes a feedback element that selectively reduces the vibration component caused by the disturbance. The transfer characteristic H2(s) is configured so that, for example, the damping coefficient on the low-pass side and the damping coefficient on the high-pass side are almost the same. Furthermore, the transfer characteristic H2(s) is a function of the center frequency f of its pass frequency band. p is the torsional resonance frequency ω of the power transmission mechanism (particularly the drive shaft 22). p It should be noted that the horizontal axis (frequency) in Fig. 10 is a logarithmic scale. In particular, when the transfer characteristic H2(s) is composed of a first-order high-pass filter and a first-order low-pass filter, the transfer characteristic H2(s) is expressed by the following equation (21).

[0096]

number

[0097] In equation (21), "τ H " "τ L ” are the time constants of the high-pass filter and the low-pass filter, respectively. L =1 / (2πf HC ),f HC =k f p ,τ H =1 / (2πf LC ),f LC =f p / k, where "k" is an arbitrary constant and "f HC " and "f LC " are the cutoff frequencies on the high and low frequency sides, respectively.

[0098] [Configuration of current control processing section] Fig. 11 is a block diagram showing the configuration of the current control processing unit 35 (see Fig. 2). As shown in Fig. 11, the current control processing unit 35 includes a voltage command value calculation unit 81, a coordinate conversion unit 82, a PWM conversion unit 83, and a coordinate conversion unit 84.

[0099] The voltage command value calculation unit 81 calculates the non-interfering voltage V d-dcpl * ,V q-dcpl * is processed by a low-pass filter to obtain a smoothed non-interfering voltage V d-dcpl-flt * ,V q-dcpl-flt * Then, the voltage command value calculation unit 81 calculates the dq-axis current i d ,i q and the dq axis current target value i d * ,i q * and the smoothed non-interfering voltage V d-dcpl-flt * ,V q-dcpl-flt * Based on this, the d-axis voltage command value V d * and q-axis voltage command value V q * (Hereinafter, the dq-axis voltage command value V d * ,Vq * The dq axis current i d ,i q is calculated by the coordinate conversion unit 84.

[0100] The coordinate conversion unit 82 calculates the dq-axis voltage command value V based on the rotor phase θ of the motor 10 according to the following equation (22): d * ,V q * is the voltage command value for each UVW phase (hereinafter referred to as the three-phase voltage command value V u * ,V v * ,V w * (called).

[0101]

number

[0102] The PWM conversion unit 83 converts the three-phase voltage command value V u * ,V v * ,V w * In response to this, a PWM signal D, which is a drive signal for a switching element of the inverter 12, is generated. uu * ,D ul * ,D vu * ,D vl * ,D wu * ,D wl * The inverter 12 is driven in response to this PWM signal, and the motor 10 generates a sixth torque target value T m6 * Motor torque T according to m is controlled to output.

[0103] The coordinate conversion unit 84 converts the U-phase current i detected by the current sensor 24 into u and V-phase current i vBased on W phase current i w Then, the coordinate conversion unit 84 calculates these currents i using the rotor phase θ of the motor 10 according to the following equation (23): u ,i v ,i w The dq axis current i d ,i q Convert into dq axis current i d ,i q is used in the voltage command value calculation unit 81 as described above.

[0104]

number

[0105] The input processing unit 31 includes a motor rotation speed calculation unit 85. The motor rotation speed calculation unit 85 calculates the motor rotation speed ω based on the rotor phase θ of the motor 10. m Calculate the following.

[0106] [Effect] The following describes the operation of the electric vehicle 100 configured as described above when the electric vehicle 100 is connected to the connecting portion 101 and tows the connected vehicle 102 to travel.

[0107] Figure 12 shows the longitudinal acceleration A L1 Specifically, FIG. 12(A) shows the time chart of the first torque target value T m1 * FIG. 12(B) is a time chart of the sixth torque target value T m6 * FIG. 12(C) is a time chart of the drive shaft torque T d FIG. 12(D) is a time chart of the motor rotation speed ω m 12(E) is a time chart of the longitudinal acceleration A of the electric vehicle 100. L1 12(F) is a time chart showing the longitudinal acceleration A of the combination vehicle 102. L2 1 is a time chart showing the above.

[0108] 12(A) to 12(F), the solid lines indicate an example in which the vibration damping control according to this embodiment is implemented, and the dashed lines indicate an example in which the vibration damping control according to the comparative example is implemented. The comparative example is an example in which the vibration damping control unit 33 does not perform the first vibration damping correction process by the front-rear vibration damping unit 36. However, even in the comparative example, the second vibration damping correction process by the power transmission mechanism vibration damping unit 37 is performed. Therefore, the sixth torque target value T m6 * In this embodiment, when the articulated vehicle 102 is not towed (T m3 * =T m1 * The sixth torque target value T m6 * is the same value as

[0109] As shown in FIG. 12(A), the first torque target value T m1 * As shown in FIG. 12(B), after time t1, the sixth torque target value T m6 * However, the request by accelerator operation (accelerator opening A po ) and the torque increases to a predetermined value according to the drive shaft torque T d is the sixth torque target value T m6 * However, in both the present embodiment (solid line) and the comparative example (dashed line), the power transmission mechanism vibration is compensated for by the second vibration damping correction process, so the drive shaft torque T d As shown in FIG. 12(D), the change in the motor rotation speed ω m is the sixth torque target value T m6 * It changes according to the change of

[0110] On the other hand, in the vibration damping control according to this embodiment and the vibration damping control according to the comparative example, the longitudinal acceleration A L1 and the longitudinal acceleration A of the combined vehicle 102 L2Specifically, as shown in Figures 12(E) and 12(F), in the control of the comparative example (dashed line) in which the first vibration damping correction process for suppressing longitudinal vibration due to towing is not performed, longitudinal vibration occurs between the electric vehicle 100 and the combination vehicle 102 due to towing the combination vehicle 102. As a result, in the control of the comparative example, the longitudinal accelerations A L1 ,A L2 This longitudinal vibration appears at the sixth torque target value T m6 * is the accelerator opening A po This longitudinal vibration continues even after time t2 when the torque converges to a value corresponding to the sixth torque target value T m6 * This continues even at time t3, when a sufficient amount of time has passed since the sixth torque target value T m6 * is the accelerator opening A po A sufficient vibration damping effect is observed to suppress longitudinal vibration even during the transition period (from time t1 to time t2) until the torque converges to a value corresponding to the torque. Furthermore, with the control of this embodiment (solid line), as shown in Figure 12(F), not only is longitudinal vibration of the electric vehicle 100 towing the combination vehicle 102 suppressed, but longitudinal vibration of the combination vehicle 102, which is the towed vehicle, is also suppressed. As a result, even when towing, the torque rises as requested by vehicle operation and smooth acceleration is achieved.

[0111] FIG. 13 shows the longitudinal acceleration A L1 13 is a time chart showing the above. That is, Fig. 13 shows a case where the weight M2 of the articulated vehicle 102 is greater than the case in Fig. 12. The parameters shown in Figs. 13(A) to (F) and the distinction between solid and dashed lines are the same as in Fig. 12.

[0112] As shown in FIGS. 13A to 13C, even when the weight M2 of the combination vehicle 102 is large, the first torque target value T m1 * , the sixth torque target value T m6 * , and drive shaft torque T d The change in the motor rotation speed ω is similar to that shown in FIGS. 12(A) and 12(B). m Although the increase in the weight M2 of the articulated vehicle 102 is suppressed, the upward trend is the same as in FIG. 12(D).

[0113] 13(E) and 13(F), in the control of the comparative example (broken line), the longitudinal accelerations A L1 ,A L2 The amplitude of the vibrations appearing in the cases of Fig. 12(E) and Fig. 12(F) is increased compared to the cases of Fig. 12(E) and Fig. 12(F). L1 ,A L2 The frequency of the vibrations appearing in the combination vehicle 102 decreases. Furthermore, the attenuation of the longitudinal vibrations is delayed, and large longitudinal vibrations continue even after time t3. These changes are due to the increase in the weight M2 of the combination vehicle 102, which changes the characteristics of the longitudinal vibrations appearing in the electric vehicle 100 and the combination vehicle 102, that is, the dynamic characteristics (natural vibration frequency ω t and the damping coefficient ζ t ) has changed.

[0114] In contrast, in the control according to this embodiment (solid line), the weight M2 of the combination vehicle 102 is increased, and thus, despite the change in dynamic characteristics as described above, the longitudinal vibrations of the electric vehicle 100 and the combination vehicle 102 are appropriately suppressed.

[0115] As described above, when the electric vehicle 100 travels while towing the combination vehicle 102, longitudinal vibrations specific to towing travel occur compared to when the electric vehicle 100 travels alone. This longitudinal vibration occurs because a large change occurs in the weight of the entire system (total weight M^), which essentially changes the transmission characteristics of the electric vehicle 100. This longitudinal vibration cannot be sufficiently suppressed by vibration damping control (second vibration damping correction process) that compensates for power transmission mechanism vibrations alone.

[0116] Therefore, in the control according to this embodiment, the first torque target value T m1 * is corrected by the first vibration damping correction process, the sixth torque target value T m6 * This sixth torque target value T m6 * The motor 10 is controlled in accordance with the above. This suppresses the longitudinal vibrations that are specific to towing. The control according to this embodiment achieves this longitudinal vibration suppression effect regardless of the weight M2 of the combination vehicle 102, which is the towed vehicle. As a result, when towing, the torque rises and smooth acceleration required by vehicle operation are achieved regardless of the weight M2 of the combination vehicle 102.

[0117] Second Embodiment In the first embodiment described above, the vibration damping control unit 33 is composed of the longitudinal vibration suppression unit 36 and the powertrain vibration suppression unit 37, and compensation for longitudinal vibrations specific to towing and compensation for powertrain vibrations are performed separately, but this is not limited to this. For example, the vibration damping control unit 33 may be configured to substantially integrally perform compensation for longitudinal vibrations specific to towing and compensation for powertrain vibrations. Below, as an example, a second embodiment will be described in which the longitudinal vibration suppression unit 36 and a feedforward compensation unit 64 (see FIG. 9), which is part of the powertrain vibration suppression unit 37, are configured integrally.

[0118] 14 is a block diagram showing a partial configuration of the vibration damping control unit 33 in the second embodiment. As shown in FIG. 14, the vibration damping control unit 33 in the second embodiment does not explicitly include the longitudinal vibration suppression unit 36 in the first embodiment. Therefore, in the vibration damping control unit 33 in the second embodiment, the feedforward compensation unit 64 m1 * The fourth torque target value T m4 * The configuration is to calculate the following.

[0119] The feedforward compensation unit 64 of this second embodiment includes a vehicle model of the electric vehicle 100 (hereinafter referred to as the electric vehicle model 91), a model of the articulated vehicle 102 connected to the connecting unit 101 (hereinafter referred to as the articulated vehicle model 92), a compensation torque calculation unit 93, and a vibration damping correction processing unit 94.

[0120] The electric vehicle model 91 calculates the fourth torque target value T m4 * (previous value) based on the fourth torque target value T m4 * The motor torque T corresponding to m (hereinafter simply referred to as the torque estimate T m Specifically, the electric vehicle model 91 is basically configured according to equations (2) to (7) which are equations of motion for the electric vehicle 100. Furthermore, the electric vehicle model 91 calculates the force f acting between the electric vehicle 100 and the combination vehicle 102 based on equations (8) to (11). 12 In this embodiment, the vehicle speed v1 of the electric vehicle 100 is calculated using the force f 12 is calculated by the articulated vehicle model 92. The weight M1 of the electric vehicle 100 used in the calculation process of the vehicle body speed v1 of the electric vehicle 100 is calculated by a configuration similar to that of the electric vehicle weight calculation unit 42 of the first embodiment. In other words, the weight M1 of the electric vehicle 100 used in the electric vehicle model 91 is a variable parameter. The torque estimation value T m is input to the compensation torque calculation unit 93. The vehicle body speed v1 is input to the articulated vehicle model 92.

[0121] The articulated vehicle model 92 is configured to calculate the vehicle body speed v2 of the articulated vehicle 102 in accordance with equations (8) to (11). Specifically, the vehicle body speed v2 of the articulated vehicle 102 is calculated as the deviation between the vehicle body speed v1 of the electric vehicle 100 and the vehicle body speed v2 of the articulated vehicle 102, i.e., the relative vehicle speed Δv 12 The relative vehicle speed Δv is calculated based on 12 In the calculation, the vehicle body speed v1 of the electric vehicle 100 is acquired from the electric vehicle model 91, and the previous value calculated by the combination vehicle model 92 is used as the vehicle body speed v2 of the combination vehicle 102.

[0122] In addition, the calculation of the vehicle body speed v2 of the articulated vehicle 102 uses the viscosity characteristic C F and elastic property K F is used. Therefore, the dynamic characteristics of the coupling section 101 to which the combination vehicle 102 is coupled are substantially reflected in the value of the vehicle body speed v2 of the combination vehicle 102. Furthermore, the weight M2 of the combination vehicle 102 used in the process of calculating the vehicle body speed v2 of the combination vehicle 102 is calculated by the same configurations as the electric vehicle weight calculation section 42, total weight calculation section 41, and combination vehicle weight calculation section 43 of the first embodiment. In other words, the weight M2 of the combination vehicle 102 used in the combination vehicle model 92 is a variable parameter. The force f calculated in the process of calculating the vehicle body speed v2 12 is input to the electric vehicle model 91. 12 is input to the compensation torque calculation unit 93. Note that the relative vehicle speed Δv 12 The dynamic characteristics of the coupling section 101 to which the combination vehicle 102 is coupled are substantially reflected in the vehicle speed v2 of the combination vehicle 102.

[0123] The compensation torque calculation unit 93 calculates the torque estimation value T m The first compensation torque T is obtained by multiplying the torque ^ by a predetermined gain K1 determined in advance by an experiment, a simulation, or the like. FF1 * Calculate the first compensation torque T FF1 *is used to compensate in advance for torque corresponding to power transmission mechanism vibration.

[0124] Furthermore, the compensation torque calculation unit 93 calculates the relative vehicle speed Δv 12 Based on this, the second compensation torque T FF2 * Calculate the second compensation torque T FF2 * is a torque compensation unit that compensates in advance for torque corresponding to longitudinal vibrations that occur when an articulated vehicle 102 is connected to the connecting portion 101. More specifically, when an articulated vehicle 102 is connected to the connecting portion 101, the compensation torque calculation unit 93 calculates the relative vehicle speed Δv 12 is multiplied by a predetermined gain K2 determined in advance by an experiment or a simulation, and the resulting value is used as the second compensation torque T FF2 * On the other hand, when no combination vehicle 102 is connected to the connection portion 101, the compensation torque calculation unit 93 sets the second compensation torque T FF2 * Let's say.

[0125] Second compensation torque T FF2 * The switching is performed by the second compensation torque switching unit 95 using the traction running signal SW T That is, the second compensation torque switching unit 95 switches the towing travel signal SW T When it is determined that the articulated vehicle 102 is connected to the connecting portion 101 based on the above, the second compensation torque T FF2 * is the relative vehicle speed Δv 12 On the other hand, the second compensation torque switching unit 95 switches the towing travel signal SW T When it is determined that the articulated vehicle 102 is connected to the connecting portion 101 based on the above, the second compensation torque T FF2 * is zero.

[0126] The compensation torque calculation unit 93 calculates the first compensation torque T FF1 * and the second compensation torque T FF2 *By adding FF3 * Therefore, the third compensation torque T FF3 * In principle, the third compensation torque T is a torque for pre-compensating for vibrations in the power transmission mechanism, but when a combination vehicle 102 is connected to the connecting portion 101, it also includes a torque for pre-compensating for the longitudinal vibrations that are specific to towing. FF3 * is input to the vibration suppression correction processing unit 94.

[0127] The vibration damping correction processing unit 94 generates a third compensation torque T FF3 * Using this, the first torque target value T m1 * By correcting the fourth torque target value T m4 * When an articulated vehicle 102 is connected to the connecting portion 101, the correction process performed by the vibration damping correction processing unit 94 is essentially a correction process including the first vibration damping correction process of the first embodiment and feedforward compensation. Therefore, the fourth torque target value T m4 * is the fourth torque target value T m4 * Therefore, the fourth torque target value T m4 * is calculated as the sixth torque target value T m6 * and is used as the final torque command value.

[0128] As described above, the longitudinal vibration suppression unit 36 and the feedforward compensation unit 64 of the first embodiment can be configured as an integrated unit. Then, the fourth torque target value T m4 * is substantially the fourth torque target value T m4 *Therefore, even when the longitudinal vibration suppression section 36 and the feedforward compensation section 64 of the first embodiment are integrated as described above, the same actions and effects as those of the first embodiment are achieved (see FIGS. 12 and 13).

[0129] The feedforward compensation unit 64 of the second embodiment essentially calculates the first torque target value T m1 * From the input of the fourth torque target value T m4 * The electric vehicle weight M1 and the combined vehicle weight M2 that constitute this transfer characteristic are variable parameters, and the second compensation torque T FF2 * Therefore, the control according to the second embodiment is configured to suppress the longitudinal vibrations specific to towing by changing (adjusting) the content of the transfer characteristics depending on whether or not the articulated vehicle 102 is connected to the connecting portion 101.

[0130] Third Embodiment In the first and second embodiments, the elasticity K F and viscosity characteristics C F is known, and the transfer characteristic G p It is assumed that the errors (modeling errors) included in (s) etc. are small enough to be negligible. However, in more practical cases, such as when a third-party trailer hitch is used, the elasticity characteristic K F and viscosity characteristics C F In addition, the elasticity characteristic K of the connecting portion 101 may change due to changes over time. F and viscosity characteristics C F In addition, depending on the actual conditions of towing, the transfer characteristic G pIn such a situation, even if the correction process for suppressing the longitudinal vibration in the first or second embodiment is performed, longitudinal vibration may still occur. In the third embodiment, the elasticity characteristic K F and viscosity characteristics C F A configuration will be described that can suitably suppress longitudinal vibration without relying on errors contained in the known values of or without relying on modeling errors.

[0131] 15 is a block diagram showing the configuration of the longitudinal vibration suppression unit 36 in the third embodiment. As shown in FIG. 15, the longitudinal vibration suppression unit 36 of the third embodiment has a natural vibration suppression unit 44 that suppresses longitudinal acceleration A L1 The natural vibration suppression unit 44 then receives the electric vehicle weight M1, the connected vehicle weight M2, and the viscosity characteristic C F and elastic property K F In addition, longitudinal acceleration A L1 Using this, the first torque target value T m1 * In addition to this, the front-rear vibration suppressor 36 is configured in the same manner as the front-rear vibration suppressor 36 of the first embodiment.

[0132] Fig. 16 is a block diagram showing the configuration of the natural vibration suppression unit 44 in the third embodiment. As shown in Fig. 16, the natural vibration suppression unit 44 in the third embodiment includes a change rate calculation unit 301, a reference response calculation unit 302, a difference calculation unit 303, a feature amount calculation unit 304, a dynamic characteristic setting unit 305, and a first vibration suppression correction processing unit 306.

[0133] The rate of change calculation unit 301 calculates the motor torque T m The rate of change of the motor torque T m In this way, the change rate calculation unit 301 determines a driving scene in which longitudinal vibration is likely to occur.

[0134] In this embodiment, the change rate calculation unit 301 calculates the first torque target value T m1 *The amount of change in the first torque target value T m1 * The time change rate of the first torque target value T m1 * The rate of change of δT m1 * More specifically, the change rate calculation unit 301 calculates the first torque target value T m1 * The previous value of T m1z * Therefore, the change rate calculation unit 301 stores the first torque target value T m1 * The current value and the previous value T m1z * or the first torque target value T m1 * The current value and the previous value T m1z * The first torque target value T m1 * The rate of change of δT m1 * The first torque target value T m1 * The rate of change of δT m1 * is effectively the motor torque T m This is a parameter that represents the rate of change (rate of change over time).

[0135] Then, the change rate calculation unit 301 calculates the first torque target value T m1 * The rate of change of δT m1 * Specifically, the first torque target value T m1 * The rate of change of δT m1 * The larger the first torque target value T m1 * The rate of change of δT m1 * When is large, the elastic property K F and viscosity characteristics C FWhen there is an error in the first torque target value T or a modeling error, the longitudinal vibration is likely to remain even if the correction process for suppressing the longitudinal vibration of the first or second embodiment is performed. Therefore, in this embodiment, the change rate calculation unit 301 calculates the first torque target value T m1 * The rate of change of δT m1 * , the change rate threshold δT TH Compared with the first torque target value T m1 * The rate of change of δT m1 * is the change rate threshold δT TH When the change rate threshold δT is greater than δT, it is determined that the driving scene is highly likely to cause longitudinal vibration. TH is the first torque target value T m1 * The rate of change of δT m1 * are set in advance based on experiments, simulations, etc.

[0136] The change rate calculation unit 301 calculates the first torque target value T m1 * The rate of change of δT m1 * and the change rate threshold δT TH The dynamic characteristics calculation flag FLG is set according to the comparison result of the longitudinal acceleration A L1 Based on the above, the natural vibration frequency ω t and the damping coefficient ζ t The dynamic characteristic calculation flag FLG is set to, for example, "1" or "0." When the flag FLG is "1," the longitudinal acceleration A L1 Based on the natural vibration frequency ω t and the damping coefficient ζ t On the other hand, when the flag FLG is "0", the natural vibration frequency ω t and the damping coefficient ζ t The change rate calculation unit 301 does not calculate the first torque target value T m1 * The rate of change of δ Tm1 *is the change rate threshold δT TH On the other hand, the change rate calculation unit 301 sets the dynamic characteristic calculation flag FLG to "1" when the first torque target value T m1 * The rate of change of δT m1 * is the change rate threshold δT TH If the following is true, the dynamic characteristic calculation flag FLG is set to "0." The change rate calculation unit 301 inputs the dynamic characteristic calculation flag FLG to, for example, the reference response calculation unit 302 or the like.

[0137] The reference response calculation unit 302 calculates the longitudinal acceleration A L1 Normative Response A L1-ref In this embodiment, when the dynamic characteristics calculation flag FLG is "1", the reference response calculation unit 302 calculates the longitudinal acceleration A L1 Normative Response A L1-ref Calculate the following.

[0138] The reference response calculation unit 302 calculates the electric vehicle weight M1, the combined vehicle weight M2, and the first torque target value T m1 * Based on this, the longitudinal acceleration A L1 Normative Response A L1-ref Specifically, the reference response calculation unit 302 calculates the first torque target value T m1 * The reference transfer characteristic G pF-ref By applying (s), the longitudinal acceleration A L1 Normative Response A L1-ref Calculate the longitudinal acceleration A L1 Normative Response A L1-ref is input to the difference calculation unit 303.

[0139]

number

[0140] In addition, the standard transmission characteristic G pF-ref (s) is the motor torque T mIt represents the reference response from the driving force F to the reference transfer characteristic G pF-ref (s) is the transfer characteristic G of Equation (17) as shown in Equation (24). pF In (s) ζ p = 1. "M" in equation (25) is the total weight of the electric vehicle 100 and the combination vehicle 102 (= M1 + M2). Transfer characteristic G pF Instead of (s), the normative transfer characteristic G pF-ref (s) is used, but the longitudinal acceleration A L1 Normative Response A L1-ref is the estimated longitudinal acceleration A L1 Since it is calculated in the same way as ^, the longitudinal acceleration A L1 Normative Response A L1-ref is an estimated value. L1 Normative Response A L1-ref The above calculation method for the longitudinal acceleration A L1 Normative Response A L1-ref can be calculated using the vehicle model expressed by the above-mentioned equation (19), for example.

[0141] The difference calculation unit 303 calculates the actual response of the longitudinal acceleration A L1 and normative response A L1-ref The difference between ΔA and L1 In this embodiment, the difference calculation unit 303 calculates the longitudinal acceleration A L1 From normative response A L1-ref By subtracting the difference ΔA L1 After the dynamic characteristic calculation flag FLG becomes "1", the difference calculation unit 303 continuously calculates the difference ΔA L1 That is, the difference ΔA L1 The difference ΔA calculated by the difference calculation unit 303 constitutes a data string that can change over time. L1 is input to the feature calculation unit 304. Note that the difference ΔA L1 The "predetermined period PP" in which the difference ΔA is calculated is set to a value that allows frequency analysis. L1The time interval is a time interval at which time series data of the front and rear vibrations can be acquired, and is determined in advance by experiment, simulation, etc., for example, from one to several seconds. Furthermore, when the frequency range of the front and rear vibrations that can occur is specified by experiment, simulation, etc., the difference calculation unit 303 outputs the difference ΔA L1 It is possible to perform filtering to extract components in a specific frequency range. In this case, the difference ΔA L1 Since noise (for example, noise due to disturbances, etc.) superimposed on the vibration is removed, the accuracy of suppressing longitudinal vibration is improved.

[0142] The feature amount calculation unit 304 calculates the feature amount of the longitudinal vibration caused by the articulated vehicle 102 being connected to the connector 101, thereby identifying the dynamic characteristics of the connector 101 to which the articulated vehicle 102 is connected. In this embodiment, the feature amount calculation unit 304 calculates the feature amount of the longitudinal vibration caused by the articulated vehicle 102 being connected to the connector 101, thereby identifying the dynamic characteristics of the articulated vehicle 102. L1 and normative response A L1-ref Difference ΔA L1 Based on this, the natural vibration frequency ω t and the damping coefficient ζ t That is, the feature amount calculation unit 304 calculates the difference ΔA L1 and calculate the natural vibration frequency ω based on the time series data. t and the damping coefficient ζ t The feature amount calculation unit 304 calculates the difference ΔA L1 By applying frequency analysis such as FFT (Fast Fourier Transform) to the time series data, the natural vibration frequency ω t and the damping coefficient ζ t In this embodiment, the feature amount calculation unit 304 can simply calculate the difference ΔA L1 Based on the number of peaks (or troughs) formed by the t and the damping coefficient ζ t Calculate the following.

[0143] As described above, the natural vibration frequency ω t and the damping coefficient ζ tThe calculation of the viscosity characteristic C of the connecting part 101 is F and elastic properties K F That is, the feature amount calculation unit 304 does not use the natural vibration frequency ω, which is a feature amount of the front-rear vibration, by a method different from that of the feature amount calculation unit 62 of the first embodiment. t and the damping coefficient ζ t The dynamic characteristics of the connecting portion 101 are determined by calculating the natural vibration frequency ω t and the damping coefficient ζ t is input to the dynamic characteristics setting unit 305.

[0144] In this embodiment, the feature amount calculation unit 304 calculates the difference ΔA L1 The acceleration threshold ΔA TH Then, compare the difference ΔA L1 is the acceleration threshold ΔA TH When the difference ΔA L1 The time series data is stored and the difference ΔA L1 Based on the time series data, the natural vibration frequency ω t and the damping coefficient ζ t That is, the difference ΔA L1 The amplitude of the acceleration threshold ΔA TH When a forward / backward vibration that cannot be ignored occurs and is larger than the amplitude determined by L1 New natural vibration frequency ω based on the time series data t and the damping coefficient ζ t On the other hand, the difference ΔA L1 The amplitude of the acceleration threshold ΔA TH If the difference ΔA is less than or equal to the value of the dynamic characteristic calculation flag FLG, the feature calculation unit 304 determines that the scene is one in which the front-rear vibration can be substantially ignored, even if it occurs. L1 New natural frequency ω based on t and the damping coefficient ζ t The calculation of acceleration threshold ΔA is not performed. TH is determined in advance by experiment, simulation, or the like.

[0145] The dynamic characteristic setting unit 305 determines the natural vibration frequency ω to be finally used as the dynamic characteristic of the connecting unit 101 for the first vibration damping correction processing unit 306. t and the damping coefficient ζ t Set.

[0146] In this embodiment, the natural vibration frequency ω t The initial value of ω t0 (not shown), and the damping coefficient ζ t The initial value ζ t0 Therefore, the dynamic characteristic calculation flag FLG is not set to "1", and the characteristic amount calculation unit 304 does not calculate the natural vibration frequency ω t and the damping coefficient ζ t When not newly calculating, the dynamic characteristic setting unit 305 sets this initial value ω t0 ,ζ t0 is the natural vibration frequency ω that is finally used as the dynamic characteristic of the connecting portion 101. t and the damping coefficient ζ t The initial value ω t0 ,ζ t0 is, for example, the viscosity characteristic C of the connecting portion 101 F and elastic properties K F , and the vehicle model of the electric vehicle 100, etc.

[0147] On the other hand, the feature amount calculation unit 304 calculates the longitudinal acceleration A L1 and normative response A L1-ref Difference ΔA L1 Based on the natural vibration frequency ω t and the damping coefficient ζ t When newly calculated, the dynamic characteristic setting unit 305 sets the newly calculated natural vibration frequency ω t and the damping coefficient ζ t is compared with an existing constant. The existing constant is the natural vibration frequency ω t and the damping coefficient ζ t For example, the previous value ω tz ,ζ tz (not shown) The natural vibration frequency ω t and the damping coefficient ζt Each previous value ω tz ,ζ tz For example, these initial values ω t0 ,ζ t0 is.

[0148] More specifically, the dynamic characteristic setting unit 305 sets the natural vibration frequency ω t and the natural vibration frequency ω t The previous value of ω tz and the frequency deviation δω t is calculated and used as the frequency threshold δω TH Compare with the frequency threshold δω TH is determined in advance by experiment, simulation, etc. t is the frequency threshold δω TH When the natural vibration frequency ω is larger than the natural vibration frequency ω, the dynamic characteristic setting unit 305 sets the natural vibration frequency ω to be used as the dynamic characteristic of the connecting portion 101. t The characteristic amount calculation unit 304 newly calculates the natural vibration frequency ω t On the other hand, the frequency deviation δω t is the frequency threshold δω TH If the natural vibration frequency ω is equal to or less than the natural vibration frequency ω , the dynamic characteristic setting unit 305 sets the natural vibration frequency ω , which is used as the dynamic characteristic of the connecting portion 101. t the previous value ω tz That is, the dynamic characteristic setting unit 305 maintains the natural vibration frequency ω t When the natural vibration frequency ω t Update.

[0149] Similarly, the dynamic characteristic setting unit 305 sets the damping coefficient ζ newly calculated by the feature amount calculation unit 304. t and the damping coefficient ζ t The previous value of ζ tz and the damping coefficient deviation δζ, which is the deviation of t is calculated and used as the attenuation coefficient threshold δζ TH Compare with the damping coefficient threshold δζ TH is determined in advance by experiment, simulation, etc., and the damping coefficient deviation δζ t is the damping coefficient threshold δζ THWhen the damping coefficient ζ is larger than the damping coefficient ζ, the dynamic characteristic setting unit 305 sets the damping coefficient ζ to be used as the dynamic characteristic of the connecting unit 101. t The feature calculation unit 304 newly calculates the attenuation coefficient ζ t On the other hand, the damping coefficient deviation δζ t is the damping coefficient threshold δζ TH or less, the dynamic characteristic setting unit 305 sets the damping coefficient ζ to be used as the dynamic characteristic of the connecting unit 101. t the previous value ζ tz That is, the dynamic characteristic setting unit 305 maintains the damping coefficient ζ t When the damping coefficient ζ t Update the natural vibration frequency ω t and the damping coefficient ζ t may be updated or maintained independently of each other.

[0150] The dynamic characteristic setting unit 305 can set the natural vibration frequency ω t Specifically, the dynamic characteristics setting unit 305 limits the range of the natural vibration frequency ω t The upper and lower limits are set for the natural vibration frequency ω t Update or maintain the natural frequency ω t The upper and lower limits of the natural vibration frequency ω that can be realistically taken during towing t The dynamic characteristics setting unit 305 determines the range of the damping coefficient ζ that can be set. t Specifically, the dynamic characteristics setting unit 305 limits the range of the damping coefficient ζ t The upper and lower limits are set for the damping coefficient ζ t Update or maintain the damping coefficient ζ t The upper and lower limits of the damping coefficient ζ that can be realistically taken in towing driving are t The dynamic characteristics setting unit 305 determines the range of the natural vibration frequency ω that can be set. t and the damping coefficient ζ tThe range of the natural vibration frequency ω t and the damping coefficient ζ t Even if there is an estimation error, the behavior of the electric vehicle 100 will not become unexpectedly unstable due to the estimation error.

[0151] The first vibration damping correction processing unit 306 calculates the natural vibration frequency ω t and the damping coefficient ζ t That is, the first vibration damping correction processor 306 is configured in the same manner as the first vibration damping correction processor 63 (see FIG. 8) of the first embodiment, except that the natural vibration frequency ω t and the damping coefficient ζ t Based on this, the first torque target value T m1 * By correcting the second torque target value T m2 * Calculate the following.

[0152] The natural vibration frequency ω in the electric vehicle 100 of the third embodiment configured as described above will be described below. t The following describes the effects of the settings.

[0153] 17 is a flowchart relating to updating of the natural vibration frequency, etc. As shown in FIG. 17, in step S301, the change rate calculation unit 301 calculates the first torque target value T m1 * The rate of change of δT m1 * In step S302, the change rate calculation unit 301 calculates the first torque target value T m1 * The rate of change of δT m1 * The change rate threshold δT TH and set the dynamic characteristics calculation flag FLG.

[0154] In step S302, the first torque target value T m1 * The rate of change of δT m1 * is the change rate threshold δTTH If the first torque target value T is greater than the first torque target value T, the dynamic characteristics calculation flag FLG is set to "1" and the process proceeds to step S303. This is a driving situation in which there is a high possibility of longitudinal vibration occurring during towing. m1 * The rate of change of δT m1 * is the change rate threshold δT TH If the natural frequency ω is t and the damping coefficient ζ t is the previous value ω tz ,ζ tz This is a driving scene in which longitudinal vibrations are unlikely to occur during towing.

[0155] In step S303, the reference response calculation unit 302 calculates the electric vehicle weight M1, the combined vehicle weight M2, and the first torque target value T m1 * Based on this, the longitudinal acceleration A L1 Normative Response A L1-ref In step S304, the difference calculation unit 303 calculates the longitudinal acceleration A L1 and normative response A L1-ref The difference between ΔA and L1 In step S305, the feature amount calculation unit 304 calculates the difference ΔA L1 and acceleration threshold ΔA TH and judge whether or not there is any significant longitudinal vibration.

[0156] In step S305, the difference ΔA L1 is the acceleration threshold ΔA TH When the natural vibration frequency ω is less than or equal to the natural vibration frequency ω, and the generated longitudinal vibration is negligible, t and the damping coefficient ζ t is the previous value ω tz ,ζ tz is maintained, and the update process shown in this flowchart ends.

[0157] On the other hand, in step S305, the difference ΔA L1 is the acceleration threshold ΔA THIf it is greater than , the process proceeds to step S306, and the feature amount calculation unit 304 calculates the difference ΔA L1 Then, in step S307, the feature amount calculation unit 304 stores the stored difference ΔA L1 Based on the time series data, a new natural frequency ω t and the damping coefficient ζ t Calculate the following.

[0158] Thereafter, in step S308, the dynamic characteristic setting unit 305 sets the natural vibration frequency ω calculated by the feature amount calculation unit 304. t The current value of and the natural vibration frequency ω t The previous value of ω tz and the frequency deviation δω t is calculated and used as the frequency threshold δω TH In step S308, the frequency deviation δω t is the frequency threshold δω TH is larger than the natural frequency ω t If it is determined that a non-negligible error has occurred in the natural vibration frequency ω of the connecting portion 101, the process proceeds to step S309. t The new natural vibration frequency ω calculated by the feature calculation unit 304 t On the other hand, in step S308, the frequency deviation δω t is the frequency threshold δω TH is less than or equal to the natural vibration frequency ω t If it is determined that there is almost no error in the calculation, step S309 is skipped.

[0159] Similarly, in step S310, the dynamic characteristic setting unit 305 sets the damping coefficient ζ calculated by the feature amount calculation unit 304. t and the damping coefficient ζ t The previous value of ζ tz and the damping coefficient deviation δζ, which is the deviation of t is calculated and used as the attenuation coefficient threshold δζ TH In step S310, the damping coefficient deviation δζ t is the damping coefficient threshold δζ TH is larger than the damping coefficient ζ tIf it is determined that a non-negligible error has occurred in the damping coefficient ζ of the coupling portion 101, the process proceeds to step S311. t The new attenuation coefficient ζ calculated by the feature calculation unit 304 t On the other hand, in step S310, the damping coefficient deviation δζ t is the damping coefficient threshold δζ TH and the damping coefficient ζ t If it is determined that there is almost no error in the calculation, step S311 is skipped.

[0160] Figure 18 shows the natural vibration frequency ω t The longitudinal acceleration A in a driving scene where the L1 18A is a time chart showing the first torque target value T m1 * FIG. 18(B) shows the second torque target value T m2 * Fig. 18(C) shows the drive shaft torque T d FIG. 18(D) shows the dynamic characteristic calculation flag FLG by a broken line, and the natural vibration frequency ω t FIG. 18(E) shows the motor rotation speed ω m FIG. 18(F) shows the longitudinal acceleration A of the electric vehicle 100 by a solid line. L1 (actual response), and the dashed line indicates the longitudinal acceleration A L1 Normative Response A L1-ref For reference, FIG. 18(G) shows the longitudinal acceleration A of the combination vehicle 102 by a solid line. L2 (actual response), and the dashed line indicates the longitudinal acceleration A L2 Normative Response A L2-ref FIG. 18(H) shows the longitudinal acceleration A of the electric vehicle 100. L1 and its normative response A L1-ref Difference ΔA L1 18. The horizontal axis of each graph in Fig. 18 represents time [s]. Time t1 is the time when the driver starts operating the accelerator, and time t2 is the time when a predetermined period PP has elapsed since time t1.

[0161] As shown in FIG. 18(A), when the accelerator is operated at time t1, the first torque target value T m1 * is input as a ramp input. As a result, the dynamic characteristic calculation flag FLG is set to "1." Then, as shown in FIGS. 18(B) and 18(C), the second torque target value T m2 * and drive shaft torque T d is the first torque target value T m1 * As shown in FIG. 18(E), after time t1, the motor rotation speed ω m generally increases over time.

[0162] In addition, as shown in FIG. 18(F), in this example, the longitudinal acceleration A L1 As shown in Figure 18(G), the longitudinal acceleration A L1 In response to the vibration, the longitudinal acceleration A of the combined vehicle 102 L2 That is, forward and backward vibration occurs in the electric vehicle 100 and the combination vehicle 102. Then, the difference ΔA L1 As shown in the figure, the longitudinal acceleration A L1 The vibration of the reference response A L1-ref 18(D), the dynamic characteristic calculation flag FLG is maintained at "1" from time t1 to time t2 after the predetermined period PP has elapsed. L1 The time series data is stored, and the difference ΔA L1 By counting the peaks of the time series data, the natural vibration frequency ω t Similarly, the feature calculation unit 304 calculates the difference ΔA L1 Based on the decrease in the amplitude of the longitudinal vibration, the damping coefficient ζ t Here, the natural vibration frequency ω used as the dynamic characteristic of the connecting portion 101 is calculated. t and the damping coefficient ζ t is the natural vibration frequency ω calculated by the feature amount calculation unit 304 t and the damping coefficient ζ tshall be updated accordingly.

[0163] Figure 19 shows the natural vibration frequency ω t The updated longitudinal acceleration A L1 19A is a time chart showing the first torque target value T m1 * FIG. 19(B) shows the second torque target value T m2 * Fig. 19(C) shows the drive shaft torque T d FIG. 19(D) shows the dynamic characteristic calculation flag FLG by a broken line, and the natural vibration frequency ω t FIG. 19(E) shows the motor rotation speed ω m FIG. 19(F) shows the longitudinal acceleration A of the electric vehicle 100 by a solid line. L1 (actual response), and the dashed line indicates the longitudinal acceleration A L1 Normative Response A L1-ref For reference, FIG. 19(G) shows the longitudinal acceleration A of the articulated vehicle 102 by a solid line. L2 (actual response), and the dashed line indicates the longitudinal acceleration A L2 Normative Response A L2-ref FIG. 19(H) shows the longitudinal acceleration A of the electric vehicle 100. L1 and its normative response A L1-ref Difference ΔA L1 19. The horizontal axis of each graph in Fig. 19 represents time [s]. Time t3 is the time when the driver starts operating the accelerator, and time t4 is the time when a predetermined period PP has elapsed since time t3.

[0164] As shown in Figure 19(A), the natural vibration frequency ω t After updating the above, when the accelerator is operated at time t3, the first torque target value T m1 * is input as a ramp input. As a result, the dynamic characteristic calculation flag FLG is set to "1." Then, as shown in FIGS. 19(B) and 19(C), the second torque target value T m2 * and drive shaft torque T d is the first torque target value T m1* As shown in FIG. 19(E), after time t3, the motor rotation speed ω m Generally, increases with time. These behaviors are due to the natural vibration frequency ω t This is the same as before the update (Figure 18).

[0165] On the other hand, as shown in FIG. 19(F), the natural vibration frequency ω t As a result of updating the above, the longitudinal acceleration A of the electric vehicle 100 L1 19(G), the longitudinal acceleration A L2 Therefore, as shown in FIG. 19(H), the difference ΔA L1 does not have a significant amplitude. Therefore, the dynamic characteristic calculation flag FLG is reset by the feature calculation unit 304 and set to "0" at least from time t3 to time t4. Therefore, the feature calculation unit 304 determines that the difference ΔA L1 New natural frequency ω based on t and the damping coefficient ζ t The natural vibration frequency ω is used as the dynamic characteristic of the connecting portion 101 without calculating t and the damping coefficient ζ t is the previous value ω tz ,ζ tz As a result, longitudinal vibrations of the electric vehicle 100 and the combination vehicle 102 are appropriately suppressed even after that.

[0166] As described above, in the electric vehicle 100 according to the third embodiment, the actual response of the longitudinal acceleration A L1 and normative response A L1-ref The difference between ΔA and L1 Based on this, the natural vibration frequency ω t and the damping coefficient ζ t is calculated. Then, this difference ΔA L1 The natural vibration frequency ω calculated based on t and the damping coefficient ζ t Based on this, the first torque target value T m1 *Therefore, in the electric vehicle 100 according to the third embodiment, the mechanical property (viscous property C F and elastic property K F Even if there is an error in the known values of the parameters (such as the rotational speed, rotational speed, etc.) or if there is a modeling error in the vehicle model, the longitudinal vibration of the electric vehicle 100 and the combination vehicle 102 is appropriately suppressed.

[0167] In the control according to the third embodiment, similarly to the first embodiment, the natural vibration frequency ω t and the damping coefficient ζ t is directly calculated, and compensation for the longitudinal vibrations specific to towing and compensation for the powertrain mechanism vibrations are performed separately. However, the control according to the third embodiment can also be implemented in a configuration in which compensation for the longitudinal vibrations specific to towing and compensation for the powertrain mechanism vibrations are performed essentially as a single unit, as in the second embodiment.

[0168] 20 is a block diagram showing a partial configuration of the vibration suppression control unit 33 when compensation for the longitudinal vibration specific to towing and compensation for the power transmission mechanism vibration are performed substantially in an integrated manner. When compensation for the longitudinal vibration specific to towing and compensation for the power transmission mechanism vibration are performed substantially in an integrated manner, as shown in FIG. 20, the feedforward compensation unit 64 of the vibration suppression control unit 33 adjusts the first torque target value T m1 * The fourth torque target value T m4 * Specifically, the feedforward compensation unit 64 is made up of an electric vehicle model 91, an articulated vehicle model 92, a compensation torque calculation unit 93, and a vibration damping correction processing unit 94. In other words, the overall configuration is the same as that of the second embodiment.

[0169] When the control of the third embodiment is performed in the vibration suppression control unit 33 (feedforward compensation unit 64), as shown in FIG. 20, the viscosity characteristic C F and elastic property K F , the electric vehicle weight M1 or the combined vehicle weight M2, and the natural vibration frequency ω t and the damping coefficient ζt That is, the dynamic characteristic setting unit 305 sets the natural vibration frequency ω t and the damping coefficient ζ t In response to this, the articulated vehicle model 92 includes a viscosity characteristic C F and elastic properties K F , the electric vehicle weight M1 included in the electric vehicle model 91, or the combined vehicle weight M2 included in the combined vehicle model 92. The dynamic characteristic setting unit 305 is configured to correct the natural vibration frequency ω t and the damping coefficient ζ t Viscosity characteristics according to C F and elastic properties K F , the electric vehicle weight M1 or the combined vehicle weight M2 can be calculated backward.

[0170] For example, the natural vibration frequency ω t When the dynamic characteristic setting unit 305 updates the natural vibration frequency ω t Elastic properties K according to F (Hereinafter, the corrected elastic property K F Then, the dynamic characteristic setting unit 305 calculates the elastic characteristic K F This corrected elastic property K F As a result, the mechanical property (viscous property C F and elastic properties K F Even if there is an error in the known values of the parameters (such as the rotational speed, rotational speed, etc.) or if there is a modeling error in the vehicle model, the longitudinal vibration of the electric vehicle 100 and the combination vehicle 102 is appropriately suppressed.

[0171] Also, for example, the damping coefficient ζ t When the damping coefficient ζ is updated, the dynamic characteristics setting unit 305 sets the damping coefficient ζ t Viscosity characteristics according to C F (Hereinafter, corrected viscosity characteristic C F Then, the dynamic characteristic setting unit 305 calculates the viscosity characteristic C F This corrected viscosity characteristic C FAs a result, the mechanical property (viscous property C F and elastic property K F Even if there is an error in the known values of the parameters (such as the rotational speed, rotational speed, etc.) or if there is a modeling error in the vehicle model, the longitudinal vibration of the electric vehicle 100 and the combination vehicle 102 is appropriately suppressed.

[0172] Natural vibration frequency ω t is the elastic property K F Since it is a parameter directly related to the natural vibration frequency ω t When updating the dynamic characteristic setting unit 305, the elastic characteristic K F Corrected elastic property K F It is particularly preferable to update the damping coefficient ζ t is the viscosity characteristic C F Since the damping coefficient ζ is a parameter directly related to t When updating the viscosity characteristic C F Correction of viscosity characteristics C F However, in the vibration damping control section 33 that essentially performs compensation for the longitudinal vibration specific to towing and compensation for the power transmission mechanism vibration in an integrated manner, the natural vibration frequency ω t and the damping coefficient ζ t Relative vehicle speed Δv 12 Therefore, the elastic property K F and viscosity characteristics C F Instead of directly updating the natural vibration frequency ω t and the damping coefficient ζ t For example, the dynamic characteristics setting unit 305 may update other parameters according to the natural vibration frequency ω t or the damping coefficient ζ t and updates the electric vehicle weight M1 included in the electric vehicle model 91 to the corrected electric vehicle weight M1'. t or the damping coefficient ζ tIn these cases, the combined vehicle weight M2 included in the combined vehicle model 92 can be updated to the corrected combined vehicle weight M2'. In these cases, as in the control of the third embodiment, the mechanical characteristics (viscosity characteristics C F and elastic property K F Even if there is an error in the known values of the parameters (such as the rotational speed, rotational speed, etc.) or if there is a modeling error in the vehicle model, the longitudinal vibration of the electric vehicle 100 and the combination vehicle 102 is appropriately suppressed.

[0173] The dynamic characteristic setting unit 305 sets the natural vibration frequency ω t or the damping coefficient ζ t Depending on the corrected elastic property K F ′, corrected viscosity characteristic C F The dynamic characteristic setting unit 305 can calculate two or more parameters from among the natural vibration frequency ω′, the corrected electric vehicle weight M1′, and the corrected combined vehicle weight M2′, and update the corresponding multiple parameters. t Based on the elastic properties K F It is preferable to correct the natural vibration frequency ω t and the damping coefficient ζ t Based on the elastic properties K F and viscosity characteristics C F It is more preferable to correct

[0174] As described above, the third embodiment can be implemented alone instead of the first embodiment or the second embodiment. However, the third embodiment can be implemented together with the first embodiment or the second embodiment. When the control according to the third embodiment is implemented together with the control according to the first embodiment, for example, the natural vibration frequency ω t and the damping coefficient ζ t Each initial value ω t0 ,ζ t0 is calculated by the feature amount calculation unit 62 of the first embodiment. t and the damping coefficient ζ tFurthermore, when the control according to the third embodiment is implemented together with the control according to the second embodiment, for example, after the electric vehicle weight M1 and the combined vehicle weight M2 are set in accordance with the respective estimated results as in the second embodiment, the natural vibration frequency ω t and the damping coefficient ζ t Depending on the elastic properties K F , viscous property C F , the electric vehicle weight M1, or the combined vehicle weight M2 may be updated.

[0175] In this way, when the control of the electric vehicle 100 according to the third embodiment is implemented together with the control of the first or second embodiment, the state in which the longitudinal vibration is suppressed by the control of the first or second embodiment becomes the standard state. F and viscosity characteristics C F This configuration particularly accurately suppresses (compensates for) longitudinal vibrations that still remain due to errors included in the known values of or modeling errors of the electric vehicle 100, etc. Therefore, when the control of the electric vehicle 100 according to the third embodiment is implemented together with the control of the first embodiment or the second embodiment, longitudinal vibrations of the electric vehicle 100 and the combination vehicle 102 can be particularly suitably suppressed.

[0176] <Modification> In each of the above-described embodiments, the electric vehicle 100 has the towing travel switch 28 as described above, and the towing travel signal SW T Whether or not the combination vehicle 102 is coupled to the coupling section 101 is determined based on the signal, but the present invention is not limited to this. For example, the towing travel switch 28 may be provided in the coupling section 101. In this case, when the combination vehicle 102 is coupled to the coupling section 101, the towing travel signal SW Tis turned on. Furthermore, if the electric vehicle 100 is equipped with a rear camera that photographs the area behind the vehicle, the image captured by the rear camera may be used to recognize the combination vehicle 102, and the motor controller 13 may determine whether or not the combination vehicle 102 is coupled to the coupling unit 101 based on the recognition result. Furthermore, when the combination vehicle weight M2 becomes a significant value, specifically, for example, when the estimated weight M2 becomes equal to or greater than a predetermined threshold value, the motor controller 13 may determine that the combination vehicle 102 is coupled to the coupling unit 101. In this case, whether or not the combination vehicle 102 is coupled to the coupling unit 101 is determined simply and directly based on whether or not the combination vehicle weight M2 is detected, without relying on the driver or the like operating the towing travel switch 28 or on recognition processing of the combination vehicle 102 using the rear camera.

[0177] In addition, in each of the above embodiments, the weights M1 and M2 of the electric vehicle 100 and the combination vehicle 102 are estimated, but these values can also be set to specified values. For example, when it is considered that the change in the weight M1 of the electric vehicle 100 can be ignored, the design weight M ini can be used. Furthermore, the weight M2 of the combination vehicle 102 can be selectively input manually depending on the vehicle type, etc. In this way, even if the weights M1, M2 of the electric vehicle 100 and combination vehicle 102 are set to specified values rather than being sequentially estimated, a vibration damping effect against the longitudinal vibrations specific to towing can be obtained, as in the above embodiments. However, by sequentially estimating the weights M1, M2 of the electric vehicle 100 and combination vehicle 102 as in the above embodiments, the longitudinal vibrations specific to towing can be particularly accurately suppressed.

[0178] Furthermore, in each of the above embodiments, power transmission mechanism vibration is suppressed, but when electric vehicle 100 does not have drive shaft 22, the suppression control of power transmission mechanism vibration can be omitted. In other words, power transmission mechanism vibration suppression unit 37 can be omitted.

[0179] In addition, in each of the above embodiments, in order to identify the dynamic characteristics of the coupling section 101 to which the articulated vehicles 102 are coupled, the viscosity characteristic CF and elastic property K F However, the present invention is not limited to this. If the coupling part 101 includes a gear, the backlash of the gear can be taken into consideration. This allows the dynamic characteristics of the coupling part 101 to which the articulated vehicles 102 are connected to be specified particularly accurately. However, as the mechanical characteristics of the coupling part 101, at least the viscosity characteristic C F and elastic property K F By taking this into consideration, the dynamic characteristics of the coupling portion 101 to which the articulated vehicles 102 are coupled can be specified to an extent that the longitudinal vibrations specific to towing can be easily and sufficiently suppressed.

[0180] In each of the above embodiments, the dynamic characteristics of the connecting portion 101 are the viscosity characteristics C F and elastic property K F The dynamic characteristics of the connecting portion 101 are specified by the elastic characteristic K F or viscosity characteristic C F However, in order to particularly effectively suppress the longitudinal vibration, the dynamic characteristics of the connecting portion 101 may be specified by at least the elastic characteristic K F That is, the first vibration damping correction process is preferably performed by determining at least the natural vibration frequency ω t Based on this, the first torque target value T m1 * The natural vibration frequency ω t The first vibration damping correction process is performed by suppressing the natural vibration frequency ω t and the damping coefficient ζ t Based on this, the first torque target value T m1 * The natural vibration frequency ω t The component of the damping coefficient ζ t It would be even better if it could be suppressed according to the

[0181] In each of the above embodiments, the electric vehicle 100 adjusts the first torque target value T m1 *However, the present invention is not limited to this. There are cases where the electric vehicle 100 performs vehicle operation. For example, when the electric vehicle 100 is an autonomous vehicle or when the electric vehicle 100 assists the driver in vehicle operation as necessary, the electric vehicle 100 determines the first torque target value T m1 * That is, the "vehicle operation" includes not only the operation of the accelerator by the driver, but also the operation of electric vehicle 100 by its own judgment to set or change vehicle variables that can be set or changed by the driver's operation.

[0182] In each of the above embodiments, the longitudinal vibrations of the electric vehicle 100 and the combination vehicle 102 are relative and related to each other, so the longitudinal acceleration A L1 The calculation using the above formula is performed based on the longitudinal acceleration A of the combined vehicle 102. L2 In addition, in each of the above embodiments, the longitudinal acceleration A of the electric vehicle 100 can be replaced with a calculation using the following equation. L1 The calculation using the formula is based on the longitudinal acceleration A of the electric vehicle 100. L1 and the longitudinal acceleration A of the combined vehicle 102 L2 However, depending on the specific combination of vehicles 102, the longitudinal acceleration A L2 Therefore, as in the above embodiments, the longitudinal acceleration A of the electric vehicle 100 can be obtained. L1 It is preferable to acquire and use the above.

[0183] As described above, the control method for an electric vehicle according to each of the above embodiments and modifications is a control method for an electric vehicle 100 that has a motor 10 as a drive source, a coupling unit 101 for coupling other vehicles, and travels by towing a combination vehicle 102 that is another vehicle coupled to the coupling unit 101. In this control method, vehicle operation (accelerator opening A po Based on the above, the torque to be output by the motor 10 (motor torque T m ) represents the basic torque target value (first torque target value T m1 *) is calculated. In addition, based on the dynamic characteristics of the coupling section 101 to which the combination vehicle 102 is coupled, a correction process (first vibration suppression correction process) is performed on the basic torque target value to suppress the longitudinal vibration component generated in the electric vehicle 100 due to the combination vehicle 102 being coupled to the coupling section 101, thereby reducing the motor torque T m The final torque command value (sixth torque target value T m6 * ) is calculated. Then, the motor 10 is controlled based on this final torque command value.

[0184] In this way, by performing correction processing to suppress the longitudinal vibrations specific to towing, the torque build-up and smooth acceleration required by vehicle operation are realized. In particular, if longitudinal vibrations occur during towing, it is difficult to achieve both the desired torque build-up and smooth acceleration, but by suppressing the longitudinal vibrations using the first vibration damping correction processing, it is possible to achieve both the desired torque build-up and smooth acceleration.

[0185] In the control method for an electric vehicle according to each of the above embodiments and modifications, in the correction process (first vibration suppression correction process) for suppressing the longitudinal vibration component, the weight of the electric vehicle 100 (electric vehicle weight M1), the weight of the combination vehicle 102 (combined vehicle weight M2), and the mechanical property of the coupling part 101 (viscosity property C F and elastic properties K F ) the dynamic characteristics of the coupling section 101 to which the combination vehicles 102 are coupled are determined based on the electric vehicle weight M1, the combination vehicle weight M2, and the mechanical characteristics of the coupling section 101. In this way, by determining the dynamic characteristics of the coupling section 101 to which the combination vehicles 102 are coupled based on the electric vehicle weight M1, the combination vehicle weight M2, and the mechanical characteristics of the coupling section 101, the longitudinal vibrations that are specific to towing are particularly accurately suppressed.

[0186] In the control method for an electric vehicle according to each of the above-described embodiments and modifications, the mechanical property of the connecting portion 101 is at least the viscosity property C F and elastic property K F That is, in order to identify the dynamic characteristics of the coupling section 101 to which the articulated vehicles 102 are coupled, at least the viscosity characteristic C F and elastic property KF In this way, the viscosity characteristic C of at least the connecting portion 101 is taken into consideration. F and elastic property K F By using the above, the dynamic characteristics of the coupling section 101 to which the articulated vehicles 102 are coupled can be easily and accurately identified.

[0187] In the control method for an electric vehicle according to each of the above-described embodiments and modifications, specifically, the longitudinal acceleration of the electric vehicle 100 (longitudinal acceleration A L1 ) is used to estimate the total weight M^ of the electric vehicle 100 and the combination vehicle 102. Also, the stroke amount ST of the suspension of the electric vehicle 100 is used to estimate the total weight M^ of the electric vehicle 100 and combination vehicle 102. FL ,ST FR ,ST RL ,ST RR The weight of the electric vehicle 100 (electric vehicle weight M1) is estimated based on the above. Then, the weight of the combination vehicle 102 (combined vehicle weight M2) is estimated by subtracting the weight of the electric vehicle 100 (electric vehicle weight M1) from the total weight M^.

[0188] The combined vehicle weight M2 differs depending on the specific combined vehicle 102. Therefore, by successively estimating the electric vehicle weight M1 and combined vehicle weight M2 when towing as described above, the longitudinal vibrations that are specific to towing can be appropriately suppressed regardless of the specific combined vehicle 102.

[0189] In the control method for an electric vehicle according to each of the above embodiments and modifications, it is determined whether or not a combination vehicle 102 is coupled to the coupling unit 101. If it is determined that the combination vehicle 102 is not coupled to the coupling unit 101, correction processing is not performed to suppress the longitudinal vibrations that are specific to towing. On the other hand, if it is determined that the combination vehicle 102 is coupled to the coupling unit 101, correction processing is performed to suppress the longitudinal vibrations that are specific to towing. In this way, by determining whether or not a towing situation is occurring and, if necessary, performing correction processing to suppress the longitudinal vibrations that are specific to towing, control stability is improved. Furthermore, the load on calculations, etc. is reduced.

[0190] In the control method for an electric vehicle according to the first embodiment and the modified example, in the correction process (first vibration suppression correction process) for suppressing the longitudinal vibrations specific to towing, the weight of the electric vehicle 100 (electric vehicle weight M1), the weight of the combination vehicle 102 (combined vehicle weight M2), and the mechanical characteristics of the coupling portion 101 (viscosity characteristics C F and elastic properties K F ) based on the natural vibration frequency ω of the longitudinal vibration component t Then, the basic torque target value (first torque target value T m1 * ) contains this natural vibration frequency ω t In this way, the natural vibration frequency ω t By specifying the above, the longitudinal vibrations that are characteristic of towing can be particularly effectively suppressed.

[0191] In the control method for an electric vehicle according to the first embodiment and the modified example, the correction process (first vibration suppression correction process) for suppressing longitudinal vibrations specific to towing is further performed by taking into account the weight of the electric vehicle 100 (electric vehicle weight M1), the weight of the combination vehicle 102 (combined vehicle weight M2), and the mechanical characteristics of the coupling portion 101 (viscosity characteristics C F and elastic properties K F ) based on the damping coefficient ζ of the longitudinal vibration component t Then, the basic torque target value (first torque target value T m1 * ) contains the natural vibration frequency ω t The component of this damping coefficient ζ t In this way, the damping coefficient ζ t Depending on the natural vibration frequency ω t By suppressing the component, the longitudinal vibrations that are characteristic of towing are suppressed particularly efficiently.

[0192] In the control method for the electric vehicle according to the first embodiment and the modified example, in particular, the correction process (first vibration suppression correction process) for suppressing the longitudinal vibrations specific to towing is performed based on the weight of the electric vehicle 100 (electric vehicle weight M1), the weight of the combination vehicle 102 (combined vehicle weight M2), and the mechanical characteristics of the coupling portion 101 (viscosity characteristics C F and elastic properties K F) based on the natural vibration frequency ω of the longitudinal vibration component t and the damping coefficient ζ t By calculating the above, the dynamic characteristics of the connecting portion 101 are identified, and the basic torque target value (first torque target value T m1 * ) contains the natural vibration frequency ω t The components of the damping coefficient ζ t In this way, the natural vibration frequency ω t and the damping coefficient ζ t The dynamic characteristics of the coupling part 101 are determined by the natural vibration frequency ω t The component of the damping coefficient ζ t By suppressing the vibration in accordance with the above, the longitudinal vibration that is specific to towing can be suppressed particularly effectively.

[0193] In the control method for an electric vehicle according to the first embodiment and the modified example, the correction process (first vibration suppression correction process) for suppressing the longitudinal vibration specific to towing is performed by adjusting the basic torque target value (first torque target value T m1 * ) at the natural vibration frequency ω t is used as the center frequency for suppression, and processing is performed using a band-stop filter that is set so that the damping coefficient (ζ in equation (20)) is equal to or greater than 1. In this way, by using a band-stop filter to perform correction processing to suppress the longitudinal vibrations specific to towing, it is possible to suppress the longitudinal vibrations specific to towing while also achieving high response.

[0194] In the control method for an electric vehicle according to the second embodiment and the modified example, in the correction process (vibration suppression correction process including the first vibration suppression correction process) for suppressing the longitudinal vibration specific to towing, the relative vehicle speed Δv between the electric vehicle 100 and the combination vehicle 102 is calculated based on the dynamic characteristics of the coupling section 101 to which the combination vehicle 102 is coupled. 12 is calculated. Also, the relative vehicle speed Δv 12 Based on this, a correction torque (second compensation torque T FF2 * ) is calculated. Then, this correction torque (second compensation torque T FF2 *) to obtain the basic torque target value (first torque target value T m1 * ) is corrected. In this way, the relative vehicle speed Δv 12 Correction torque based on the second compensation torque T FF2 * ) to calculate the basic torque target value (first torque target value T m1 * When correcting for , the longitudinal vibrations that are characteristic of towing are suppressed and particularly high response is achieved.

[0195] In the control method for an electric vehicle according to the third embodiment and the modified example, the correction process for suppressing the longitudinal vibrations specific to towing (the first vibration damping correction process or the vibration damping correction process including the first vibration damping correction process) is performed by adjusting the longitudinal acceleration (A L1 ) based on the natural vibration frequency ω of the longitudinal vibration component t , damping coefficient ζ t , or natural vibration frequency ω t and the damping coefficient ζ t Furthermore, this correction process (the first vibration damping correction process or the vibration damping correction process including the first vibration damping correction process) is configured to specify the dynamic characteristics of the connecting portion 101 by calculating both of the basic torque target value (the first torque target value T m1 * ) contains the natural vibration frequency ω t In this way, the longitudinal acceleration A of the electric vehicle 100 is suppressed. L1 Based on this, the natural frequency ω t and / or damping coefficient ζ t Identify the natural vibration frequency ω t When the component of the connecting portion 101 is suppressed, the mechanical property (viscous property C F and elastic properties K F Even if there is an error in the longitudinal acceleration A L1Therefore, according to the control methods for electric vehicles according to the third embodiment and the modified example, there is no need to provide additional new sensors or the like to suppress the longitudinal vibrations that are specific to towing, and longitudinal vibrations can be suppressed accurately without increasing costs.

[0196] In the control method for an electric vehicle according to the third embodiment and the modified example, the correction process (first vibration damping correction process or vibration damping correction process including the first vibration damping correction process) for suppressing the longitudinal vibration specific to towing is performed by adjusting the longitudinal acceleration (longitudinal acceleration A L1 ) based on the natural vibration frequency ω of the longitudinal vibration component t and the damping coefficient ζ t By calculating the above, the dynamic characteristics of the connecting portion 101 are identified, and the basic torque target value (first torque target value T m1 * ) contains the natural vibration frequency ω t The components of the damping coefficient ζ t In this way, the longitudinal acceleration (A L1 ) based on the natural vibration frequency ω t and the damping coefficient ζ t Identify the natural vibration frequency ω t The component of the damping coefficient ζ t When the mechanical properties (K F ,C F Even if there is an error in the vehicle model of the electric vehicle 100 or the vehicle model of the electric vehicle 100, the longitudinal vibrations that are specific to towing are particularly effectively suppressed.

[0197] In the control method for an electric vehicle according to the third embodiment and the modified example, the correction process for suppressing the longitudinal vibrations specific to towing (the first vibration damping correction process or the vibration damping correction process including the first vibration damping correction process) is performed by adjusting at least the basic torque target value (the first torque target value T m1 * ) change rate (δT m1 * ) is the predetermined threshold (δT TH ) is greater than the first torque target value T m1 *The rate of change of δT m1 * Based on this, driving scenes in which longitudinal vibrations are likely to occur are determined, and the first vibration damping correction process is executed at least in such driving scenes, thereby particularly accurately suppressing longitudinal vibrations of the electric vehicle 100 and the combination vehicle 102.

[0198] In the control method for an electric vehicle according to the third embodiment and the modified example, the correction process for suppressing the longitudinal vibrations specific to towing (the first vibration damping correction process or the vibration damping correction process including the first vibration damping correction process) is performed by adjusting the longitudinal acceleration (A L1 ) normative response A L1-ref Calculate the longitudinal acceleration (A L1 ) and longitudinal acceleration (A L1 ) normative response A L1-ref The difference between ΔA and L1 Based on this, the natural frequency ω t and the damping coefficient ζ t In this way, the difference ΔA L1 Based on the natural vibration frequency ω t and the damping coefficient ζ t By calculating the elastic property K F and viscosity characteristics C F The accurate natural vibration frequency ω is calculated based on the actual value, regardless of the known value of ω or modeling error. t and the damping coefficient ζ t is estimated. As a result, longitudinal vibrations of the electric vehicle 100 and the combination vehicle 102 are particularly appropriately suppressed. When the control of the electric vehicle according to the third embodiment and the modified example is carried out together with the control of the first embodiment or the second embodiment, longitudinal vibrations that remain even after the control of the first embodiment or the second embodiment is carried out can be appropriately suppressed.

[0199] In the control method for an electric vehicle according to the third embodiment and the modification, the longitudinal acceleration (A L1 ) normative response A L1-ref is the basic torque target value (first torque target value T m1 *), the weight of the electric vehicle 100 (M1), and the weight of the combination vehicle 102 (M2). L1 Normative Response A L1-ref The first torque target value T m1 * and the estimated values of the electric vehicle weight M1 and the combined vehicle weight M2, the longitudinal acceleration A L1 Normative Response A L1-ref As a result, longitudinal vibrations of the electric vehicle 100 and the combination vehicle 102 are particularly effectively suppressed.

[0200] In the control method for an electric vehicle according to the third embodiment and the modified example, the correction process for suppressing the longitudinal vibrations specific to towing (the first vibration suppression correction process or the vibration suppression correction process including the first vibration suppression correction process) is performed by adjusting the acquired longitudinal acceleration (A L1 ) and longitudinal acceleration (A L1 ) normative response A L1-ref The difference between ΔA and L1 By performing frequency analysis on t and the damping coefficient ζ t In this way, the actual response, longitudinal acceleration A L1 and longitudinal acceleration A L1 Normative Response A L1-ref The difference between ΔA and L1 By performing frequency analysis on t and the damping coefficient ζ t By calculating the above, a particularly accurate natural vibration frequency ω corresponding to the actual longitudinal vibration can be obtained. t and the damping coefficient ζ t As a result, longitudinal vibrations of the electric vehicle 100 and the combination vehicle 102 are particularly effectively suppressed.

[0201] In the control method for the electric vehicle according to the third embodiment and the modification, the correction process (first vibration-damping correction process or vibration-damping correction process including the first vibration-damping correction process) for suppressing the longitudinal vibration specific to towing is performed by adjusting the dynamic characteristics (ω t ,ζ t ) is the previous value (ω tz ,ζtz ) with a predetermined threshold (δω TH ,δζ TH ), the dynamic characteristics are updated. In this way, when the natural vibration frequency ω t and damping coefficient ζ t By updating the natural vibration frequency ω t and damping coefficient ζ t The sensitive change of the natural vibration frequency ω is suppressed when it is truly necessary. t and damping coefficient ζ t is updated appropriately. As a result, longitudinal vibrations of the electric vehicle 100 and the combination vehicle 102 are suppressed particularly effectively.

[0202] In the control method for an electric vehicle according to the third embodiment and the modified example, the correction process for suppressing the longitudinal vibration specific to towing (the first vibration-damping correction process or the vibration-damping correction process including the first vibration-damping correction process) is performed by adjusting the natural vibration frequency ω t and the damping coefficient ζ t The natural vibration frequency ω is limited to a predetermined range (a range of values that can be realistically obtained during towing). t and the damping coefficient ζ t By restricting the range of t and the damping coefficient ζ t Even if an estimation error is included in the calculated speed, the behavior of the electric vehicle 100 is prevented from becoming unstable due to the estimation error.

[0203] In the control method for an electric vehicle according to the third embodiment and the modified example, the correction process for suppressing the longitudinal vibrations specific to towing (the first vibration damping correction process or the vibration damping correction process including the first vibration damping correction process) is performed by adjusting the longitudinal acceleration (A L1 ) based on the natural vibration frequency ω of the longitudinal vibration component t and the damping coefficient ζ t Calculate the natural vibration frequency ω t and the damping coefficient ζ t Based on this, the mechanical properties (K F ,CF ), or the weight (M1, M2) of the electric vehicle 100 or the combination vehicle 102 is corrected, and the mechanical characteristics (K F ′,C F '), or the corrected weights (M1', M2') of the electric vehicle 100 or the combination of vehicles 102, the relative vehicle speed Δv 12 Calculate the relative vehicle speed Δv 12 Based on this, the correction torque (T FF2 * ) and calculate the correction torque (T FF2 * ) to obtain the basic torque target value (first torque target value T m1 * In this way, the longitudinal acceleration (A L1 ) based on the natural vibration frequency ω t and / or damping coefficient ζ t Identify the natural vibration frequency ω t When the component of the connecting portion 101 is suppressed, the mechanical property (viscous property C F and elastic properties K F Even if there is an error in the longitudinal acceleration A L1 Therefore, according to the control methods for electric vehicles according to the third embodiment and the modified example, there is no need to provide additional new sensors or the like to suppress the longitudinal vibrations that are specific to towing, and longitudinal vibrations can be suppressed accurately without increasing costs.

[0204] The above describes embodiments and modifications of the present invention, but the configurations described in the above embodiments and modifications merely represent some of the application examples of the present invention and are not intended to limit the technical scope of the present invention.

[0205] This application claims priority based on Japanese Patent Application No. 2022-006018, filed with the Japan Patent Office on January 18, 2022, the entire contents of which are incorporated herein by reference.

Claims

1. A method for controlling an electric vehicle that has a motor as a drive source and a coupling unit that couples another vehicle, and that travels by towing a combination vehicle that is the other vehicle coupled to the coupling unit, comprising: calculating a basic torque target value representing a torque to be output by the motor based on a vehicle operation; calculating a final torque command value that is a final command value for the torque by performing a correction process on the basic torque target value based on the dynamic characteristics of the coupling section to which the combination vehicles are coupled, the correction process suppressing a longitudinal vibration component that occurs in the electric vehicle due to the combination vehicles being coupled to the coupling section; controlling the motor based on the final torque command value; A method for controlling an electric vehicle.

2. 2. A control method for an electric vehicle according to claim 1, In the correction process, the dynamic characteristics are identified based on the weight of the electric vehicle, the weight of the connected vehicles, and the mechanical characteristics of the connection portion. A method for controlling an electric vehicle.

3. 3. The method for controlling an electric vehicle according to claim 2, The mechanical properties of the coupling portion include at least viscous properties and elastic properties of the coupling portion. A method for controlling an electric vehicle.

4. 3. The method for controlling an electric vehicle according to claim 2, estimating a total weight of the electric vehicle and the combined vehicle based on a longitudinal acceleration of the electric vehicle; estimating a weight of the electric vehicle based on a stroke amount of a suspension of the electric vehicle; estimating the weight of the combination of vehicles by subtracting the weight of the electric vehicle from the total weight; A method for controlling an electric vehicle.

5. A control method for an electric vehicle according to any one of claims 1 to 4, The correction process includes: determining the dynamic characteristics by calculating a natural vibration frequency and a damping coefficient of the longitudinal vibration component based on the weight of the electric vehicle, the weight of the connected vehicles, and the mechanical characteristics of the connecting portion; a component of the natural vibration frequency included in the basic torque target value is suppressed in accordance with the damping coefficient; The control method for an electric vehicle is configured as follows.

6. 6. A control method for an electric vehicle according to claim 5, the correction process is performed by processing the basic torque target value using a band-stop filter that has the natural vibration frequency as a center frequency of suppression and that is set so that the damping coefficient is 1 or more. A method for controlling an electric vehicle.

7. A control method for an electric vehicle according to any one of claims 1 to 4, The correction process includes: calculating a relative vehicle speed between the electric vehicle and the combination vehicle based on the dynamic characteristics; calculating a correction torque for the longitudinal vibration component based on the relative vehicle speed; The basic torque target value is corrected using the correction torque. The control method for an electric vehicle is configured as follows.

8. A control method for an electric vehicle according to any one of claims 1 to 4, The correction process includes: calculating a natural vibration frequency and a damping coefficient of the longitudinal vibration component based on a longitudinal acceleration of the electric vehicle, thereby identifying the dynamic characteristics; a component of the natural vibration frequency included in the basic torque target value is suppressed in accordance with the damping coefficient; The control method for an electric vehicle is configured as follows.

9. 9. A method for controlling an electric vehicle according to claim 8, The correction process is configured to be executed at least when a rate of change of the basic torque target value is greater than a predetermined threshold value. A method for controlling an electric vehicle.

10. 9. A method for controlling an electric vehicle according to claim 8, The correction process includes: Calculating a reference response of the longitudinal acceleration; calculating the natural vibration frequency and the damping coefficient based on a difference between the acquired longitudinal acceleration and the reference response of the longitudinal acceleration; The control method for an electric vehicle is configured as follows.

11. The method for controlling an electric vehicle according to claim 10, The reference response of the longitudinal acceleration is calculated based on the basic torque target value, a weight of the electric vehicle, and a weight of the combined vehicle. A method for controlling an electric vehicle.

12. The method for controlling an electric vehicle according to claim 10, The correction process includes: calculating the natural vibration frequency and the damping coefficient by performing a frequency analysis process on a difference between the acquired longitudinal acceleration and the reference response of the longitudinal acceleration; The control method for an electric vehicle is configured as follows.

13. 9. A method for controlling an electric vehicle according to claim 8, The correction process includes: updating the dynamic characteristics when the dynamic characteristics have changed by a larger amount than a predetermined threshold value from the previous value; The control method for an electric vehicle is configured as follows.

14. A control method for an electric vehicle according to any one of claims 1 to 4, The correction process includes: calculating a natural vibration frequency and a damping coefficient of the longitudinal vibration component based on a longitudinal acceleration of the electric vehicle; correcting the mechanical characteristics of the coupling portion or the weight of the electric vehicle or the coupled vehicle based on the natural vibration frequency and the damping coefficient; calculating a relative vehicle speed between the electric vehicle and the combination vehicle based on the corrected mechanical characteristics of the coupling portion or the corrected weight of the electric vehicle or the combination vehicle; calculating a correction torque for the longitudinal vibration component based on the relative vehicle speed; The basic torque target value is corrected using the correction torque. The control method for an electric vehicle is configured as follows.

15. A control device for an electric vehicle that has a motor as a drive source and a coupling unit that couples another vehicle, and that travels by towing a coupled vehicle that is the other vehicle coupled to the coupling unit, a basic torque target value calculation unit that calculates a basic torque target value that represents a torque to be output by the motor based on a vehicle operation; a correction processing unit that calculates a final torque command value that is a final command value for the torque by performing a correction process on the basic torque target value based on dynamic characteristics of the coupling section to which the combination vehicles are coupled, the correction process suppressing longitudinal vibration components that occur in the electric vehicles due to the combination vehicles being coupled to the coupling section; and Equipped with controlling the motor based on the final torque command value; Control device for electric vehicles.

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