Vehicle control device

Abstract

To appropriately achieve improved energy efficiency through drive control of a rotating electric machine based on discontinuous torque commands, and reduced vibration caused in a drive transmission mechanism.SOLUTION: A torque command generation part 11 of a vehicle control device selectively executes discontinuous command generation processing PWM and normal command generation processing Normal, while adding vibration damping torque Tco to requested torque Tmg* on the basis of a vibration index Tco representing the magnitude of vibration in a drive transmission mechanism. When the vibration index Tco becomes equal to or greater than a first threshold TH_co during execution of the discontinuous command generation processing PWM, the torque command generation part 11 terminates the discontinuous command generation processing PWM and executes the normal command generation processing Normal.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 10-243680 discloses a control device that controls the drive of a rotating electric machine based on a discontinuous torque command (pulse-shaped torque command) whose average value coincides with a specified required torque and whose peak value coincides with a torque value that can drive the rotating electric machine with high efficiency. Regardless of the required torque, the rotating electric machine can be driven in an efficient operating range, allowing the rotating electric machine to operate with high energy efficiency. Therefore, improvement in the power consumption rate (electricity cost) of hybrid vehicles and electric vehicles can be expected. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-243680 Summary of the Invention [Problem to be solved by the invention]

[0004] The output torque of a rotating electric machine may include not only a drive torque for propelling a vehicle but also a damping torque for reducing vibrations generated in a drive transmission mechanism, such as a drive shaft, from the rotating electric machine to the wheels. The damping torque is a torque in the opposite phase to the vibration components generated in the drive transmission mechanism. By superimposing this torque on the drive torque, the output torque of the rotating electric machine reduces the vibrations while the vehicle is propelled, providing a comfortable ride for passengers. However, when a discontinuous pulse torque command is compared with a normal continuous torque command, the normal torque command provides better responsiveness for rotating electric machine control based on the torque command. The frequency of the damping torque is often higher than the period (so-called carrier period) of the pulse torque command. Therefore, when the damping torque is output as output torque of the rotating electric machine, a delay in response may cause a phase shift between the damping torque in the torque command and the output torque. Such a phase shift may lead to a deterioration in vibration control performance and an amplification of vibration.

[0005] Therefore, it is desirable to appropriately improve energy efficiency by controlling the drive of a rotating electrical machine based on a discontinuous torque command and reduce vibrations occurring in the drive transmission mechanism. [Means for solving the problem]

[0006] In view of the above, a vehicle control device is provided that controls a vehicle equipped with a rotating electric machine as a driving force source for wheels, and includes a torque command generation unit that generates a torque command, which is a command for causing the rotating electric machine to output a required torque, based on a required torque, which is a torque that is required to be transmitted to the wheels. The torque command generation unit executes a vibration control process that adds a vibration control torque to the required torque, which causes the rotating electric machine to output a torque that is in the opposite phase to vibration of a drive transmission mechanism, based on a vibration index that represents the magnitude of vibration of the drive transmission mechanism that transmits the driving force of the rotating electric machine to the wheels, and selectively executes a discontinuous command generation process that generates a discontinuous command value as the torque command, and a normal command generation process that generates a continuously changing command value as the torque command. If the vibration index becomes equal to or greater than a predetermined first threshold value during the execution of the discontinuous command generation process, the torque command generation unit terminates the discontinuous command generation process and executes the normal command generation process.

[0007] According to this configuration, when the vibration index becomes equal to or greater than the first threshold, the torque command generation process is switched from the discontinuous command generation process to the normal command generation process. Therefore, when vibration control is performed, it is possible to prevent the effects of the vibration control from being inappropriately achieved due to the use of a discontinuous command value as a torque command to drive and control the rotating electric machine. For example, this reduces the possibility that vibration reduction by the vibration control will be insufficient or will actually increase, making it easier to perform appropriate vibration control. Furthermore, according to this configuration, when the vibration index is less than the first threshold, i.e., when the vibration of the drivetrain mechanism is relatively small, the torque command generated by the discontinuous command generation process is used to drive and control the rotating electric machine, thereby intermittently operating the rotating electric machine and improving the energy efficiency of the vehicle. In other words, this configuration appropriately achieves both improved energy efficiency by controlling the rotating electric machine based on a discontinuous torque command and reduced vibration occurring in the drivetrain mechanism.

[0008] Further features and advantages of the vehicle control device will become apparent from the following description of exemplary, non-limiting embodiments that refer to the drawings. [Brief explanation of the drawings]

[0009] [Figure 1] Schematic block diagram showing an example of a drive control system for a rotating electric machine [Figure 2] Schematic control block diagram of a rotating electrical machine via an inverter [Figure 3] FIG. 1 is a diagram illustrating an example of a drive transmission mechanism between a rotating electric machine and wheels; [Figure 4] A diagram showing the operating range of a rotating electrical machine as a function of rotational speed and torque. [Figure 5] FIG. 1 is a diagram showing the relationship between a normal continuous torque command and a discontinuous torque command. [Figure 6] 1 is a time chart showing an example of the relationship between an oscillation-damping torque, a torque command including the oscillation-damping torque, and a type of torque command generation process; [Figure 7] A control block diagram showing an example of a torque command generation unit including a rotation speed feedback vibration suppression controller. [Figure 8] A flowchart showing an example of a procedure for switching between a PWM command generation process and a normal command generation process. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of a vehicle control device will be described with reference to the drawings. The schematic block diagram of Fig. 1 shows an example of a drive control system for a rotating electric machine 4. The schematic control block diagram of Fig. 2 shows an example of a control form for the rotating electric machine 4 via an inverter 7. Fig. 3 shows an example of a drive transmission mechanism 5 between the rotating electric machine 4 and wheels W.

[0011] The vehicle control device 1 controls at least an AC rotating electric machine 4 that is a driving force source for wheels W. As shown in FIG. 1, the drive control system for the rotating electric machine 4 includes the vehicle control device 1 and an inverter 7. In this embodiment, the vehicle control device 1 includes a driving control function unit (for example, driving control device 2) and a rotating electric machine control function unit (for example, rotating electric machine control device 3). The driving control device 2 controls the rotating electric machine 4 to generate a required torque Tmg in response to the driver's operation of an accelerator pedal, a brake pedal, or the like (all not shown), or commands from an adaptive cruise control system, a parking assistance system, an automatic braking system, or the like (all not shown). * The rotary electric machine control device 3 generates the required torque Tmg by, for example, current feedback control, which will be described later. * The rotating electrical machine 4 is driven and controlled via the inverter 7 so as to output the above.

[0012] In this embodiment, the rotating electric machine 4 includes a stator 42 having a multi-phase (here, three-phase) stator coil 43, and a rotor 41 having a field magnet. If the rotating electric machine 4 is a permanent magnet synchronous rotating electric machine (PMSM: Permanent Magnet Synchronous Motor), the rotor 41 includes a permanent magnet. If the rotating electric machine 4 is an electrically excited synchronous rotating electric machine (EESM: Electrically Excited Synchronous Motor), the rotating electric machine 4 includes an electromagnet using a field winding (rotor coil) instead of a permanent magnet as a field source. In this embodiment, the rotating electric machine 4 will be described as a PMSM.

[0013] 2, the vehicle control device 1 includes a current feedback control unit 12 and a modulation unit 13. In this embodiment, the current feedback control unit 12 and the modulation unit 13 are provided in the rotary electric machine control device 3. The current feedback control unit 12 is configured to * Torque command T based on *Based on the rotational position of the rotor 41 (magnetic field pole position), the rotational speed of the rotor 41, and the currents flowing through the stator coils 43 of each of the three phases, current feedback control using, for example, vector control is performed to drive and control the rotating electric machine 4 via the inverter 7. In the vector control method, feedback control is performed by converting the currents flowing through the stator coils of each phase into vector components of the d-axis, which is the direction of the magnetic field in the rotor 41, and the q-axis, which is orthogonal to the d-axis (a direction leading the magnetic field direction by an electrical angle of π / 2). The coordinate system after the coordinate conversion is called a dq-axis orthogonal coordinate system. Vector control is well known, so a detailed description will be omitted. The modulator 13 modulates the voltage command generated by the current feedback controller 12 to generate a pulse signal for controlling the switching of the switching elements of the inverter 7.

[0014] The current flowing through the stator coil 43 is detected by a current sensor 61. The rotational position and rotational speed of the rotor 41 are detected by a rotation sensor 62, such as a resolver or an inductive position sensor. The rotating electric machine control device 3 (current feedback control unit 12) is configured to have various functional units for current feedback control, and each functional unit is realized by cooperation between hardware such as a microcomputer configured with an electronic circuit as its core and software (program). Note that the vehicle control device 1 is configured to have various functional units in addition to the current feedback control unit 12, modulation unit 13, and torque command generation unit 11 (described later), and each functional unit is realized by cooperation between hardware such as a microcomputer configured with an electronic circuit as its core and software (program).

[0015] The stator coil 43 is connected to the DC power supply 6 via the inverter 7. A DC link capacitor 63 (smoothing capacitor) that smoothes the voltage on the DC side of the inverter 7 is provided on the DC side of the inverter 7, i.e., between the inverter 7 and the DC power supply 6. The rotating electrical machine control device 3 controls the switching of the inverter 7, which is made up of a plurality of switching elements, and causes the inverter 7 to convert power between DC and multi-phase (three-phase in this embodiment) AC.

[0016] The inverter 7 is configured with a plurality of switching elements. The inverter 7 has a plurality of sets (three sets in this example) of arms for one AC phase, each set being a series circuit of an upper-stage switching element on the positive side of DC and a lower-stage switching element on the negative side. The switching elements are power transistors such as IGBTs (Insulated Gate Bipolar Transistors), power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), and HEMTs (High Electron Mobility Transistors).

[0017] The DC power supply 6 is configured by, for example, a rechargeable secondary battery (battery) such as a lithium ion battery, an electric double layer capacitor, etc. When the rotating electric machine 4 is the driving power source of the vehicle as in this embodiment, the DC power supply 6 is a high-voltage, large-capacity DC power supply, and its rated voltage is, for example, 200 to 800 volts.

[0018] The rotating electric machine 4 has a function as a motor that receives power from the DC power supply 6 to generate power, and a function as a generator that receives power from the wheels W to generate power. That is, the rotating electric machine 4 generates driving force by running using the power stored in the DC power supply 6, and also generates power using the driving force transmitted from the wheels W to charge the DC power supply 6.

[0019] As shown in FIG. 3 , in this embodiment, the drive transmission mechanism 5 that transmits power between the rotating electric machine 4 and the wheels W includes an input member 51, a gear mechanism 50, and a drive shaft 59. The input member 51 is connected to the rotor shaft 40 that rotates integrally with the rotor 41 of the rotating electric machine 4, and rotates integrally with the rotor shaft 40 and the rotor 41. The input member 51 is drivingly connected to a transmission (here, a reducer) configured, for example, by a spur gear counter gear mechanism, a planetary gear mechanism, or the like. The transmission (reduction gear) may have a fixed gear ratio (fixed reduction ratio), or may be a stepped transmission (reduction gear). The reducer is drivingly connected to a differential gear mechanism 55 (distribution differential gear mechanism) that distributes power to a pair of wheels W. The differential gear mechanism 55 distributes power to a pair of drive shafts 59, and power from the rotating electric machine 4 is transmitted to the pair of wheels W via the pair of drive shafts 59. The differential gear mechanism 55 may be configured by a bevel gear type or a planetary gear type. In this embodiment, an electric vehicle equipped with only the rotating electric machine 4 as a driving force source for the wheels W is exemplified, but this does not preclude the vehicle from being a hybrid vehicle also equipped with an internal combustion engine.

[0020] In addition, when a reducer using a planetary gear mechanism is provided and the reducer is arranged coaxially with the rotor 41, the differential gear mechanism 55 can be arranged on a separate, parallel axis from the rotor 41, and the vehicle drive device 10 including the rotating electric machine 4 can have, for example, a two-shaft configuration. In addition, when a reducer using a counter gear mechanism is provided, the vehicle drive device 10 can have a three-shaft configuration with three parallel axes, or a two-shaft configuration with two parallel axes in which the differential gear mechanism 55 is arranged coaxially with the rotor 41, folding back from the reducer. In addition, the vehicle drive device 10 can have a single-shaft configuration in which one drive shaft 59 penetrates radially inside the rotor shaft 40, and the rotor 41, the reducer using a planetary gear mechanism, and the differential gear mechanism 55 using a planetary gear mechanism are arranged coaxially. Naturally, the vehicle drive device 10 may be configured with four or more rotating axes.

[0021] In this specification, the term "driving connection" refers to a state in which two rotating elements are connected to each other so as to transmit a driving force, and includes a state in which the two rotating elements are connected to rotate integrally, or a state in which the two rotating elements are connected to each other so as to transmit a driving force via one or more transmission members. Examples of such transmission members include various components that transmit rotation at the same speed or at variable speeds, such as shafts, gear mechanisms, belts, and chains. The transmission members may also include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices and meshing engagement devices. In this specification, the term "integrally rotated" refers to integral rotation regardless of whether the components are separable or inseparable. In other words, multiple components that rotate integrally may be integrally formed from the same material, or may be made of separate materials and integrated by welding, spline connection, or the like.

[0022] As described above, the current feedback control unit 12 calculates the required torque Tmg, which is the torque that is required to be transmitted to the wheels W. * Based on this, current feedback control is performed to drive and control the rotating electric machine 4 via the inverter 7. Here, the "torque required to be transmitted to the wheels W" is considered to be equivalent to the "torque to be output from the rotating electric machine 4", and the "required torque" is defined as "Tmg * " Required torque Tmg * is provided from the cruise control device 2 based on information from the accelerator pedal, etc., as described above.

[0023] As shown in FIG. 2, the vehicle control device 1 of this embodiment calculates the required torque Tmg * Based on this, the rotating electric machine 4 is supplied with a required torque Tmg * The torque command T * That is, the torque command generating unit 11 generates the required torque Tmg * Based on this, the rotating electric machine 4 is requested to generate a torque Tmg * Torque command T to output *In this embodiment, the torque command generating unit 11 performs the torque command generating process to generate the required torque Tmg * The torque command T * and the discontinuous command generation process to generate the required torque Tmg * The torque command T * The process is configured to be able to selectively execute a normal command generation process that generates a command as follows:

[0024] As will be described later, in the present embodiment, in the discontinuous command generation process, the torque command T is generated as a pulse width modulation waveform that switches between an ON state and an OFF state at a switching timing defined based on a control period Pcnt that is shorter than the set carrier period Pca. * For example, it is preferable that the carrier period Pca is set to about 10 [Hz]. The control period Pcnt is approximately 1000 times the carrier period, or approximately 5 to 20 [kHz]. The carrier period Pca may be predetermined as a fixed value, or may be variably set within a predetermined range. The torque command generation unit 11 may be provided in the travel control device 2 or in the rotating electrical machine control device 3.

[0025] Torque command T of pulse width modulation waveform * When the rotating electric machine 4 is driven by the carrier frequency, the on-state and the off-state are switched within the carrier period Pca, and therefore, torque fluctuations according to the carrier frequency may occur in the output torque of the rotating electric machine 4. For this reason, the carrier period Pca is set to be equal to the torque command T * The period is set so that torque fluctuations of the rotating electric machine 4, which is drive-controlled by the torque fluctuation control circuit, are not perceived by vehicle occupants. Perception by occupants includes vibrations caused by torque fluctuations and sounds generated by torque fluctuations. For example, the sounds (audible noise) are evaluated based on frequencies observed in a path from the mount of the rotating electric machine 4 as an input to the seat rails that secure the seat in place inside the vehicle cabin, through experiments and simulations using an actual vehicle.

[0026] 4 and 5, the torque command T * As shown in FIG. 5, the torque command generation process (discontinuous command generation process = pulse width modulation command generation process) for generating the required torque Tmg * is provided to the torque command generator 11 as a continuously changing command value. The torque command generator 11 calculates the required torque Tmg at a strobe point (or a compare point) defined in the carrier period Pca. * In this embodiment, the torque command generator 11 acquires the value of the required torque Tmg at the starting point of the carrier period Pca. * The latched required torque Tmg is fetched. * The value of is the torque command T generated as a pulse width modulated waveform. * This corresponds to the average value in the carrier period Pca of the PWM average command value Tpwm0 * It is called.

[0027] The carrier period Pca is controlled by a carrier counter. The carrier counter is a counter that increments from zero at a control period Pcnt that is shorter than the carrier period Pca. When it reaches a set maximum value, it returns to zero and repeats the counting operation. In this embodiment, the value of the carrier counter is referred to as a counter value CNT. If this maximum value is fixed, the carrier period Pca becomes a fixed value. If the maximum value is variable, the carrier period Pca can be made variable. Naturally, this counter may be in a form that decrements from the maximum value to zero, or may be a timer that measures from the maximum value to zero.

[0028] Incidentally, the rotating electric machine 4 has an operating region where loss is small and it can operate with high energy efficiency. FIG. 4 shows the operating region of the rotating electric machine 4 indicated by the rotation speed and torque of the rotating electric machine 4. The first region R1 in FIG. 4 is a region where energy efficiency is higher than that of the second region R2, and the second region R2 is a region where energy efficiency is higher than that of the third region R3. For example, when the speed of the rotating electric machine 4 is "V1", the torque "Tef" is a highly efficient torque that the rotating electric machine 4 can output with high energy efficiency. In the pulse width modulation command generation process, the torque command T in the ON state is * The torque command T is set so that the on-torque value Ton, which is the value of * is generated. The carrier frequency (1 / carrier period Pca) is a frequency that is sufficiently high relative to the frequency at which the average torque that balances with the running resistance RL changes. Therefore, torque fluctuations of the high-frequency components that correspond to the carrier frequency and are included in the output torque of the rotating electric machine 4 are not transmitted to the rotating shaft of the wheel W, and only the low-frequency components (average torque) of the output torque are transmitted to the wheel W.

[0029] In this embodiment, the torque command T * In other words, the torque command generating unit 11 generates a torque (high efficiency torque Tef) that is set in accordance with the rotation speed of the rotating electrical machine 4 and falls within a high efficiency range (for example, a first region R1) in which the efficiency of the rotating electrical machine 4 is higher than a predetermined specified value, by using the torque command T * (on-torque value Ton), and zero is the torque command T * The value (off torque value Toff) is set to be the value of the torque required for the DC power supply 6 to be turned on. When the pulse width modulation waveform is in the off state, it is preferable to control all switching elements of the inverter 7 to be in the off state and shut down the inverter 7. Since no current flows from the DC power supply 6 to the stator coil 43 via the inverter 7, it is possible to improve the power efficiency (power consumption rate).

[0030] The high efficiency range may be set on a map such as that shown in FIG. 4, or may be set based on an efficiency (for example, an index obtained by dividing output power by power consumption) determined according to the vehicle speed (the rotation speed of the rotating electric machine 4).

[0031] In the pulse width modulation command generation process, the torque integral value in the carrier period Pca is first calculated as the PWM average command value Tpwm0 * To match the PWM basic command Tpwm * Specifically, the torque command generation unit 11 calculates an on-duty Don, which is the on-state period of the pulse width modulation waveform. Since the off-duty Doff, which is the off-state period of the pulse width modulation waveform, is the period obtained by subtracting the on-duty Don from the carrier period Pca, it is sufficient to calculate the on-duty Don. The torque command generation unit 11 generates a PWM basic command Tpwm using the following equation (1): * Calculate the on-duty Don of

[0032] Don(for Tpwm * )=(Tpwm0 * / Tef)·Pca···(1)

[0033] The on-duty Don calculated in this way is an ideal value, as will be described later. The vehicle control device 1 including the torque command generation unit 11 is configured with a processor such as a microcomputer as its core, and executes processing depending on a control period that depends on a clock or the like. For this reason, command values ​​transmitted between functional units, information input and acquired from the outside, and information and signals output to the outside change for each control period determined by the processor. In the pulse width modulation command generation process, the PWM torque command Tpwm having a pulse width modulation waveform also becomes a signal (information) that changes for each control period. The PWM torque command Tpwm of this embodiment also changes for each control period Pcnt. The torque command generation unit 11 generates a torque command (PWM torque command Tpwm) as a pulse width modulation waveform that switches between an on state and an off state at a switching timing defined based on the control period Pcnt, which is shorter than the carrier period Pca, during a set carrier period Pca. In contrast, the PWM basic command Tpwm * is the required torque Tmg * This is a virtual and ideal command that is set as a waveform that switches between an ON state and an OFF state in response to the command, regardless of the control period Pcnt.

[0034] As described above, the resolution of the PWM torque command Tpwm depends on the control period Pcnt. The on-duty Don of the PWM torque command Tpwm is the product of the control period Pcnt and the counter value CNT (for example, "CNTon") corresponding to the on-period, as shown in the following equation (2).

[0035] Don(for Tpwm)=Pcnt·CNT···(2) (Don(for Tpwm)=Pcnt·CNTon···(2))

[0036] In this embodiment, as shown in the following formula (3), the PWM basic command Tpwm *The counter value CNT (=CNTon) corresponding to the on-duty Don of the PWM torque command Tpwm is calculated by dividing the on-duty Don by the control period Pcnt. In this embodiment, the calculation is performed using an integer operator (such as Int), and the counter value CNT is calculated by rounding down.

[0037] CNT = Don(for Tpwm * ) / Pcnt···(3) (CNTon=Don(for Tpwm * ) / Pcnt···(3))

[0038] The on-duty Don of the PWM torque command Tpwm calculated by rounding down is the PWM basic command Tpwm in each carrier period Pca. * The length is less than the on-duty Don.

[0039] As described above, the torque command generator 11 calculates the required torque Tmg * The torque command T * and the discontinuous command generation process (here, pulse width modulation command generation process) that generates the required torque Tmg * The command value (e.g., the required torque Tmg) changes continuously depending on the * The torque command T * The process is configured to be able to selectively execute a normal command generation process that generates a command as follows:

[0040] Incidentally, vibrations such as resonance vibrations may occur in the drive transmission mechanism 5 from the rotary electric machine 4 to the wheels W due to the influence of disturbance torque from the road surface, etc. Here, drive shaft vibrations occurring in the drive shaft 59 are taken as an example of vibrations that are easily felt by occupants. By causing the rotary electric machine 4 to output torque in the opposite phase to this drive shaft vibration, the drive shaft vibration can be offset and suppressed. This type of control is called vibration suppression control. Details will be described later with reference to Figures 6 and 7, but specifically, the drive shaft vibration is extracted and a vibration suppression torque Tco is set in the opposite phase with the same amplitude as the drive shaft vibration (the vibration suppression torque Tco here is the same as the command value). The required torque Tmg mentioned above * By superimposing the command value of this damping torque Tco on the drive shaft vibration (in the case of drive shaft vibration itself, the required torque Tmg * If it is in the opposite phase, the required torque Tmg is subtracted from * (addition to vibration compensation torque Tmg_co * is obtained.

[0041] The vehicle control device 1 determines the required torque Tmg * Instead of the vibration compensation required torque Tmg_co * 5 and the like, and by controlling the rotary electric machine 4 to drive based on the PWM torque command Tpwm, the vehicle can be driven while reducing drive shaft vibration by the output torque of the rotary electric machine 4, thereby providing passengers with a more comfortable ride. However, the PWM torque command Tpwm, which is a discontinuous command, and the required torque Tmg, which is a normal continuous command, * and vibration compensation torque requirement Tmg_co * Compared with the torque command T * The response of the rotating electrical machine control based on this is good. In addition, the frequency of the damping torque Tco is controlled by the pulse-like torque command T * Therefore, when the damping torque Tco is output as the output torque of the rotary electric machine 4, the torque command T * (Vibration compensation required torque Tmg_co* The phase of the damping torque Tco in the output torque may be out of phase with the phase of the damping torque Tco in the output torque. Such a phase shift may result in a decrease in damping performance. Furthermore, depending on the degree of phase shift, it may actually lead to an increase in vibration amplitude.

[0042] Therefore, in this embodiment, the vehicle control device 1 is configured to achieve both improved energy efficiency by controlling the drive of the rotating electric machine 4 based on a discontinuous torque command (PWM torque command Tpwm) and reduced vibrations occurring in the drive transmission mechanism 5 (e.g., drive shaft 59).

[0043] 7, the vehicle control device 1 is configured such that the torque command generating unit 11 executes the vibration suppression process and is also capable of selectively executing a discontinuous command generating process (here, a PWM command generating process) and a normal command generating process as the torque command generating process. Here, the vibration suppression process is a process of calculating a vibration suppression torque Tco, which causes the rotary electric machine 4 to output a torque in the opposite phase to the vibration of the drive transmission mechanism 5, based on a vibration index (for example, drive shaft vibration) that indicates the magnitude of vibration of the drive transmission mechanism 5 that transmits the driving force of the rotary electric machine 4 to the wheels W, as a required torque Tmg. * The damping torque Tco is a torque command in the opposite phase to the drive shaft vibration, which is used to cancel out the drive shaft vibration, and so can be used as a vibration index. Naturally, the torque of the detected drive shaft vibration may also be used as a vibration index.

[0044] In addition, the discontinuous command generation process is a process of generating a discontinuous command value as a torque command T * In this embodiment, the normal torque command generation process corresponds to the PWM torque command generation process described above. * The torque command T *When the vibration damping torque Tco (vibration index) becomes equal to or greater than the vibration damping threshold value TH_co (first threshold value) during execution of the discontinuous command generation process (PWM command generation process), torque command generation unit 11 ends the PWM command generation process (PWM) and executes the normal command generation process (Normal).

[0045] When the vibration index is drive shaft vibration or damping torque Tco for canceling it, damping threshold TH_co can be the amplitude of damping torque Tco. The damping threshold TH_co may have different values ​​for positive and negative amplitudes. That is, the absolute value of the positive-direction damping threshold TH_coH and the absolute value of the negative-direction damping threshold TH_coL may be different values. Unless otherwise specified, the following description will be given assuming that the absolute value of the positive-direction damping threshold TH_coH and the absolute value of the negative-direction damping threshold TH_coL are the same. That is, the description will be given assuming that damping threshold TH_co is a determination index for the absolute value of the amplitude of damping torque Tco. Furthermore, since the judgment using the vibration damping threshold value TH_co is performed sequentially, there is no need to maintain the value of the amplitude of the vibration damping torque Tco between peak to peak (Top to Top) and valley to valley (Bottom to Bottom) of the vibration damping torque Tco and then compare it with the vibration damping threshold value TH_co; it is sufficient to compare the value (absolute value) of the changing vibration damping torque Tco with the vibration damping threshold value TH_co.

[0046] The vibration-damping torque Tco and the torque command including the vibration-damping torque Tco (vibration compensation required torque Tmg_co) shown in Fig. 6 are * ) and the type of torque command generation process, a control block diagram shown in FIG. 7 showing an example of a torque command generation unit 11 including a rotation speed feedback vibration suppression controller, and a flowchart shown in FIG. 8 showing an example of a procedure for switching between PWM command generation process (PWM) and normal command generation process (Normal).

[0047] In the time chart of FIG. 6, PWM command generation processing is executed before time t1. At time t1, when the absolute value of oscillation-damping torque Tco becomes equal to or greater than oscillation-damping threshold TH_co (when oscillation-damping torque Tco becomes equal to or less than negative-direction oscillation-damping threshold TH_coL), torque command generator 11 terminates PWM command generation processing (PWM) and executes normal command generation processing (Normal). As shown in FIG. 6, oscillation-damping torque Tco oscillates with a relatively large amplitude after time t1. By executing normal command generation processing here, oscillation-damping processing can be executed appropriately. Between time t1 and time t2, oscillation-damping torque Tco oscillates with an amplitude equal to or greater than oscillation-damping threshold TH_co. Between the peak and the trough and between the trough and the peak, the absolute value of oscillation-damping torque Tco temporarily becomes less than oscillation-damping threshold TH_co. However, because a waiting time Pconv (described later) is set, the torque command generation processing method does not switch from the normal command generation processing to the PWM command generation processing between time t1 and time t2.

[0048] After time t2, the amplitude of damping torque Tco becomes small enough not to exceed damping threshold TH_co. At time t2, the absolute value of damping torque Tco becomes less than damping threshold TH_co (damping torque Tco becomes less than positive direction damping threshold TH_coH). If the absolute value of damping torque Tco remains less than damping threshold TH_co until time t3, torque command generator 11 terminates the normal command generation process and executes the PWM command generation process. This period "Pconv" from time t2 to time t3 is called the standby time.

[0049] For ease of explanation, the embodiment has been described in which the determination value (referred to as the "first threshold") when switching from the PWM command generation process to the normal command generation process and the determination value (referred to as the "second threshold") when switching from the normal command generation process to the PWM command generation process via a standby time are the same vibration damping threshold TH_co. However, the first threshold and the second threshold may be different values. Because the second threshold is the determination value when switching from the normal command generation process to the PWM command generation process, it is preferable that the second threshold has an absolute value smaller than that of the first threshold. As described above, the first threshold and the second threshold may be the same value, so it is preferable that the second threshold be a value equal to or smaller than the first threshold.

[0050] That is, when the absolute value of damping torque Tco, which is a vibration index, becomes less than the second threshold value while the normal command generation process is being executed, torque command generation unit 11 terminates the normal command generation process and executes PWM command generation process (discontinuous command generation process) after a predetermined waiting time Pconv has elapsed from the time when the absolute value of damping torque Tco becomes less than the second threshold value.

[0051] If the amplitude of the vibration damping torque Tco fluctuates across the vibration damping threshold TH_co, frequent switching between normal command generation processing and PWM command generation processing may occur, resulting in so-called hunting and a lack of control stability. However, by providing the wait time Pconv as described above, frequent switching between normal command generation processing and PWM command generation processing can be suppressed even if the first threshold and the second threshold are the same value. Therefore, problems caused by frequent switching of the torque command generation method (e.g., delays in vibration damping when vibration damping control is required, or torque disturbances when the torque command mode is switched) can be made less likely to occur. To suppress false detection, it is preferable that the wait time Pconv be set to a period at least longer than the resonance period of the drive transmission mechanism 5 (drive shaft 59).

[0052] If the second threshold is less than the first threshold, the standby time Pconv can be shortened. For example, if the second threshold is close to zero, the normal command generation process switches to the PWM command generation process when the damping torque Tco is barely needed. In such a situation, the damping torque Tco does not exceed the first threshold. Therefore, if the second threshold is sufficiently smaller than the first threshold, the standby time Pconv can be extremely short, or the torque command generation process can be switched smoothly without providing the standby time Pconv. Therefore, the standby time Pconv does not prevent the normal command generation process from switching to the PWM command generation process without going through the standby time Pconv.

[0053] 6, after switching to PWM command generation processing at time t3, the absolute value of oscillation-damping torque Tco again becomes equal to or greater than oscillation-damping threshold TH_co (oscillation-damping torque Tco becomes equal to or greater than positive direction oscillation-damping threshold TH_coH) at time t4, which causes torque command generator 11 to terminate the PWM command generation processing and execute the normal command generation processing.

[0054] Here, vibration suppression control (vibration suppression processing) will be described. Vibration suppression control is performed by rotation speed feedback control. As shown in FIG. 7, torque command generation unit 11 extracts vibration components of drive transmission mechanism 5 (drive shaft 59) based on the rotation speed ω of rotating electric machine 4 detected by rotation sensor 62 by passing the signal through a high pass filter HPF, a band pass filter BPF and a gain amplifier. This makes it possible to obtain vibration suppression torque Tco. As shown in FIG. 7, torque command generation unit 11 calculates vibration suppression torque Tco based on the extracted vibration components as a required torque Tmg. * By subtracting from the * is gaining popularity.

[0055] The torque command generating unit 11 further includes a comparator CMP and a multiplexer MUX. The comparator compares the vibration-damping torque Tco with the vibration-damping threshold TH_co, and provides the result of the determination to the multiplexer MUX. The multiplexer MUX generates a vibration compensation request torque Tmg_co in accordance with the determination result of the comparator CMP. * PWM torque command Tpwm based on the vibration compensation request torque Tmg_co * That is, the torque command T * to the current feedback control unit 12. For ease of explanation, the control block diagram in FIG. 7 does not take into consideration the standby time Pconv.

[0056] The torque generation process switching procedure, including the standby time Pconv, will be described below with reference to the flowchart in FIG. 8. As described above with reference to FIG. 7, first, damping torque Tco is calculated (#1). Next, it is determined whether the absolute value of damping torque Tco is less than damping threshold TH_co (#2). Note that here, an example is shown in which the first threshold and the second threshold are the same value, and the positive direction damping threshold TH_coH and negative direction damping threshold TH_coL for the first threshold and the second threshold are the same value. If these have different values, multiple determination steps corresponding to step #2 are provided. Since this can be easily understood by those skilled in the art, an example flowchart and detailed explanation will be omitted.

[0057] If the condition of step #2 is satisfied, it is next determined whether the vibration of the drive transmission mechanism 5, for example, the vibration of the drive shaft 59, is in a converged state. Specifically, it is determined whether the condition of step #2 is satisfied for a period equal to or longer than the waiting time Pconv. Here, it is determined whether the convergence flag Fconv is in an enabled state (=1) (step #3). The convergence flag Fconv is a flag that is in an enabled state (=1) when the condition of step #2 is satisfied for a period equal to or longer than the waiting time Pconv, and is in an disabled state (=0) otherwise.

[0058] If the condition of step #3 is satisfied, the torque command generating unit 11 generates a PWM torque command Tpwm and converts the PWM torque command Tpwm into a torque command T * As shown in step #4 of FIG. 8, when the conditions of step #3 are satisfied and further when the PWM torque command applicable conditions (sometimes simply referred to as "PWM conditions") are satisfied, the torque command generating unit 11 generates the PWM torque command Tpwm and outputs the PWM torque command Tpwm as the torque command T * The PWM torque command applicable conditions are, for example, (1) the required torque Tmg * The two conditions are: (1) the absolute value of is less than the torque in a high-efficiency range (for example, the first region R1) in which the rotating electric machine 4 can be driven with high efficiency, and (2) the vehicle speed (linear with the rotation speed ω of the rotating electric machine 4) is less than a reference speed. The reference speed is the lowest speed at which the rotating electric machine 4 is subjected to field-weakening control.

[0059] If the determination condition is not met in step #3, that is, if the convergence flag Fconv is not in a valid state (=1), the value of the counter (here, "Pconv") that measures the waiting time Pconv is incremented by one (#6). Next, it is determined whether the incremented counter value is equal to or greater than the waiting time determination value TH_conv (#7). If the counter value is equal to or greater than the waiting time determination value TH_conv, the convergence flag Fconv is set to a valid state (=1) (#8). Then, if the PWM torque command applicability condition is met, a PWM command generation process is executed, and the PWM torque command Tpwm is set to the torque command T * If the value of the counter is less than the waiting time determination value TH_conv, the convergence flag Fconv is maintained in the invalid state (=0), and the torque command generator 11 executes the normal command generation process to generate a normal torque command (for example, a vibration compensation request torque Tmg_co * ) to the torque command T * (#11)

[0060] If it is determined in step #2 that the absolute value of the amplitude of vibration-damping torque Tco is equal to or greater than vibration-damping threshold value TH_co, then convergence flag Fconv is set to an invalid state (=0) (#9). This setting includes resetting the invalid state (=0) of convergence flag Fconv to the invalid state (=0). Next, in step #10, the value of the counter that measures waiting time Pconv is cleared to zero (reset). As with convergence flag Fconv, if the counter value is already zero, the counter value is also cleared to zero in step #10 following step #9. Then, in the following step #11, torque command generator 11 executes normal command generation processing to generate a normal torque command (for example, vibration compensation request torque Tmg_co * ) to the torque command T * Output as

[0061] For example, between time t1 and time t2 in FIG. 6, as damping torque Tco transitions from peak to trough and back again, the absolute value of damping torque Tco may become less than damping threshold TH_co. In this case, the value of the counter measuring standby time Pconv is incremented while damping torque Tco is between positive-direction damping threshold TH_coH and negative-direction damping threshold TH_coL. However, between time t1 and time t2, the amplitude of damping torque Tco is greater than damping threshold TH_co, so the absolute value of damping torque Tco becomes equal to or greater than damping threshold TH_co by the time the counter value reaches standby time determination value TH_conv. As a result, the value of the counter measuring standby time Pconv is cleared, and the process does not switch from normal command generation processing to PWM command generation processing.

[0062] The vehicle control device (1) described above will be briefly summarized below.

[0063] In one aspect, the vehicle control device (1) is a vehicle control device (1) for controlling a vehicle equipped with a rotating electric machine (4) as a driving force source for wheels (W), and a required torque (Tmg) which is a torque required to be transmitted to the wheels (W) is *) to the rotating electrical machine (4), * ) is the torque command (T * The torque command generation unit (11) generates the required torque (Tmg), and the torque command generation unit (11) generates a damping torque (Tco) for causing the rotating electric machine (4) to output a torque in the opposite phase to the vibration of the drive transmission mechanism (5) based on a vibration index (Tco) representing the magnitude of vibration of the drive transmission mechanism (5) that transmits the driving force of the rotating electric machine (4) to the wheels (W). * ), and a discontinuous command value is added to the torque command (T * ) as a discontinuous command generation process (PWM), and a continuously changing command value as the torque command (T * When the vibration index (Tco) becomes equal to or greater than a first threshold value (TH_co) defined in advance during the execution of the discontinuous command generation process (PWM), the torque command generation unit (11) terminates the discontinuous command generation process (PWM) and executes the normal command generation process (Normal).

[0064] According to this configuration, when the vibration index (Tco) becomes equal to or greater than the first threshold value (TH_co), the torque command (T * ) generation process is switched from discontinuous command generation process (PWM) to normal command generation process (Normal). Therefore, when vibration suppression control is performed, the discontinuous command value is * ) to drive and control the rotating electric machine, it is possible to prevent the effect of the vibration damping process from being inappropriately obtained. For example, it is possible to reduce the possibility that the vibration reduction by the vibration damping control will be insufficient or that the vibration will increase, and it becomes easier to perform appropriate vibration damping control. Furthermore, according to this configuration, when the vibration index (Tco) is less than the first threshold value (TH_co), that is, when the vibration of the drive transmission mechanism (5) is relatively small, the torque command (T *) to drive and control the rotating electric machine (4), the rotating electric machine (4) can be operated intermittently to improve the energy efficiency of the vehicle. * ) can appropriately realize improvement in energy efficiency by drive control of the rotating electric machine (4) based on the above, and reduction in vibration occurring in the drive transmission mechanism (5).

[0065] Furthermore, when the vibration index (Tco) becomes less than a second threshold value that is set equal to or less than the first threshold value (TH_co) during execution of the normal command generation process (Normal), it is preferable that the torque command generation unit (11) terminates the normal command generation process (Normal) and executes the discontinuous command generation process (PWM) after a predetermined waiting time (Pconv) has elapsed since the vibration index (Tco) became less than the second threshold value (TH_co).

[0066] When the vibration index (Tco) fluctuates around the first threshold (TH_co), there is a risk of frequent switching between the normal command generation process (Normal) and the discontinuous command generation process (PWM), resulting in a lack of control stability. However, with this configuration, by providing a waiting time (Pconv), it is possible to suppress frequent switching between the normal command generation process (Normal) and the discontinuous command generation process (PWM) even if the first threshold (TH_co) and the second threshold are the same value. If the second threshold is less than the first threshold (TH_co), it is even easier to suppress such frequent switching.

[0067] In addition, the torque command generating unit (11) generates the torque command (T) as a pulse width modulated waveform in the discontinuous command generating process (PWM) in which an ON state and an OFF state are switched at a switching timing defined based on a control period (Pcnt) shorter than a predetermined carrier period (Pca) within the carrier period (Pca). * ), and the torque command generation unit (11) generates the required torque (Tmg) at a reference timing within the carrier cycle (Pca). *It is preferable to determine the duty of the pulse width modulation waveform for each carrier period (Pca) in accordance with the carrier period (Pca) and the damping torque (Tco).

[0068] The discontinuous command generation process (PWM) generates a torque command (T * ), the torque command (T * ) is updated only every carrier period (Pca). Therefore, the phase of the output torque from the rotating electrical machine (4) is likely to be out of phase with respect to the phase of the vibration damping torque (Tco). As a result, the vibration damping process may not sufficiently reduce the vibration, or may even increase the vibration. Therefore, the discontinuous command generation process (PWM) generates a torque command (T * When generating a command (Tco), if the configuration is such that normal command generation processing (Normal) and discontinuous command generation processing (PWM) can be switched based on the vibration index (Tco) as in this configuration, it is easy to obtain the effects of improving energy efficiency and appropriately realizing vibration suppression processing.

[0069] In addition, the torque command generating unit (11) generates the torque command (T) as a pulse width modulated waveform in the discontinuous command generating process (PWM) in which an ON state and an OFF state are switched at a switching timing defined based on a control period (Pcnt) shorter than a predetermined carrier period (Pca) within the carrier period (Pca). * ), and the torque command generation unit (11) generates a torque (Tef) that is set according to the rotation speed (ω) of the rotating electric machine (4) and falls within a high efficiency range (R1) in which the efficiency of the rotating electric machine (4) is higher than a predetermined specified value, based on the torque command (T * ) (Ton) and zero is the value (Toff) for the pulse width modulated waveform in the off state.

[0070] According to this configuration, when the pulse width modulation waveform is in an on state, the rotating electric machine (4) is driven with a highly efficient torque (Tef), and when the pulse width modulation waveform is in an off state, the rotating electric machine (4) is driven so as not to output any torque, so that the rotating electric machine (4) can be driven efficiently. [Explanation of symbols]

[0071] 1: Vehicle control device, 4: Rotating electric machine, 5: Drive transmission mechanism, 11: Torque command generation unit, Normal: Normal command generation processing, Pca: Carrier cycle, Pcnt: Control cycle, Pconv: Waiting time, PWM: PWM command generation processing (discontinuous command generation processing), R1: First region (high efficiency range), T * : torque command, TH_co: vibration suppression threshold (first threshold, second threshold), Tco: vibration suppression torque, Tef: high efficiency torque (torque in which the efficiency of the rotating electrical machine falls within a high efficiency range, which is an operating range in which the efficiency is higher than a predetermined specified value), Tmg * : Required torque (command value that changes continuously), Tmg_co * : Vibration compensation required torque (command value that changes continuously), Toff: Off torque value (torque command value when pulse width modulation waveform is on), Ton: On torque value (torque command value when pulse width modulation waveform is off), Tpwm: PWM torque command (discontinuous command value), W: Wheel, ω: Rotational speed

Claims

1. A vehicle control device for controlling a vehicle equipped with a rotating electric machine as a driving force source for wheels, a torque command generation unit that generates, based on a required torque that is a torque that is required to be transmitted to the wheels, a torque command that is a command for causing the rotating electric machine to output the required torque, The torque command generation unit a vibration damping torque that causes the rotary electric machine to output a torque in an opposite phase to the vibration of the drive transmission mechanism based on a vibration index that indicates the magnitude of vibration of the drive transmission mechanism that transmits the driving force of the rotary electric machine to the wheels, and a discontinuous command generating process for generating a discontinuous command value as the torque command; a normal command generation process for generating a continuously changing command value as the torque command; When the vibration index becomes equal to or greater than a predetermined first threshold value during execution of the discontinuous command generation process, the torque command generation unit terminates the discontinuous command generation process and executes the normal command generation process.

2. 2. The vehicle control device according to claim 1, wherein, when the vibration index becomes less than a second threshold value that is set equal to or less than the first threshold value during execution of the normal command generation process, the torque command generation unit terminates the normal command generation process and executes the discontinuous command generation process after a predetermined waiting time has elapsed from the time when the vibration index becomes less than the second threshold value.

3. the torque command generation unit generates the torque command as a pulse width modulated waveform that switches between an on state and an off state within a predetermined carrier period at a switching timing that is defined based on a control period that is shorter than the carrier period, in the discontinuous command generation process; 3. The vehicle control device according to claim 1, wherein the torque command generating unit determines a duty of the pulse width modulation waveform for each carrier cycle in accordance with the required torque and the vibration damping torque at a reference timing within the carrier cycle.

4. the torque command generation unit generates the torque command as a pulse width modulated waveform that switches between an on state and an off state within a predetermined carrier period at a switching timing that is defined based on a control period that is shorter than the carrier period, in the discontinuous command generation process; 3. The vehicle control device according to claim 1, wherein the torque command generation unit is set according to a rotation speed of the rotating electric machine, and sets the torque command value when the pulse width modulation waveform is in an on state to a torque that falls within a high efficiency range, which is an operating range in which the efficiency of the rotating electric machine is higher than a predetermined specified value, and sets zero as the value when the pulse width modulation waveform is in an off state.

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