Vehicle control system

Abstract

A control system (1) includes a higher-level control device (10) and a lower-level control device (20) that can communicate with each other. The higher-level control device (10) calculates a first limit power (Pt1) by subtracting a margin (M) from initial power corresponding to chargeable / dischargeable power (SOP) of a battery, performs limit processing on driver request torque (Td) with the first limit power (Pt1), and transmits motor request torque (Tm) calculated on the basis of torque (Tt1) after the limit processing and a second limit power (Pt2) obtained by adding the margin (M) to the first limit power (Pt1) to the lower-level control device (20). The lower-level control device (20) performs vibration suppression control by adjusting the motor request torque (Tm), performs the limit processing on the adjusted torque (Tv) with the second limit power (Pt2), and controls a motor on the basis of the torque (Tt2) after the limit processing.

Description

Vehicle control system

[0001] The present invention relates to a control system installed in a vehicle including a driving battery and a driving motor.

[0002] Conventionally, technologies for improving ride comfort by suppressing vibration and shock in vehicles (electric vehicles) capable of traveling with a motor powered by a driving battery have been proposed (see, for example, Patent Documents 1 and 2). In such technologies (vibration suppression control), motor control is implemented, for example, by adding or subtracting torque for suppressing vibration and shock to or from the required torque, or by limiting the amount of torque change. In addition to vibration suppression control, in electric vehicles, from the perspective of battery protection, torque limitation in accordance with the chargeable / dischargeable power of the battery can be implemented.

[0003] Japanese Patent Application Laid-Open No. 2020-58156, Japanese Patent Application Laid-Open No. 2022-58067

[0004] Processes (functions) such as calculation of required torque, implementation of vibration suppression control, calculation of battery chargeable / dischargeable power, and torque limitation are allocated to a plurality of control devices mounted on the vehicle. For example, a host control device calculates required torque, a BMU (Battery Management Unit) calculates the chargeable / dischargeable power of the battery and transmits it to the host control device, and the host control device transmits the required torque limited according to the chargeable / dischargeable power to an MCU (Motor Control Unit). The MCU adjusts the required torque to suppress vibration, and finally determines the torque to be instructed to the motor (instructed torque). In this way, through cooperation of a plurality of control devices, the torque intended by the driver is achieved while suppressing vibration, and the battery is also protected.

[0005] However, in torque adjustment by the MCU, when vibration suppression torque is added to the required torque transmitted from the host control device to the MCU, the instructed torque may exceed the torque limited by the host control device in accordance with the chargeable / dischargeable power. If this excess state continues for a long time, it causes deterioration of the battery, and reduces the performance (commercial value) of the electric vehicle.

[0006] In response to this, one possible approach is to set a larger margin (safety margin) when limiting torque according to the charge / discharge power, thereby narrowing the usable range of power so that even if the MCU adjusts the torque, the instructed torque does not exceed the limited torque. However, with this method, even when an excess condition does not occur (for example, when the torque added or subtracted during torque adjustment is small, or when torque adjustment is not necessary at all), the usable range of power is limited. Therefore, this method does not fully utilize the battery's performance, and for example, it does not sufficiently extend the motor's driving range or improve energy efficiency.

[0007] The vehicle control system in this case was devised in light of the above-mentioned challenges, and one of its objectives is to achieve the torque intended by the driver while suppressing vibrations, and to fully utilize the performance of the battery while protecting it. In addition to this objective, another objective of this case is to produce effects and benefits that cannot be obtained with conventional technology, which are derived from each of the configurations shown in the "Modes for Carrying Out the Invention" described later.

[0008] The vehicle control system disclosed can be implemented in the following embodiments (examples of application) and solves at least some of the above-mentioned problems. Each of embodiments 2 to 6 is an additional embodiment that can be appropriately selected and each is an embodiment that can be omitted. None of embodiments 2 to 6 disclose any embodiments or configurations that are essential to this case.

[0009] Embodiment 1. The disclosed vehicle control system is provided in a vehicle equipped with a drive battery and a drive motor, and includes a higher-level control device and a lower-level control device that can communicate with each other. The higher-level control device includes a first limiting power calculation unit that calculates a first limiting power, which is the maximum power that the motor can use for powering or regeneration, by subtracting a predetermined margin from an initial power corresponding to the chargeable and dischargeable power of the battery; a first limiting unit that performs limiting processing with the first limiting power on a driver-requested torque based on the driver operation of the vehicle; a motor-requested torque calculation unit that calculates a motor-requested torque based on the torque after limiting processing transmitted from the first limiting unit and transmits it to the lower-level control device; a setting unit that sets the margin; and a second limiting power calculation unit that transmits to the lower-level control device a second limiting power, which is the first limiting power plus the margin. The lower-level control device includes a vibration damping control unit that performs vibration damping control by adjusting the motor-requested torque; a second limiting unit that performs limiting processing with the second limiting power on an adjusted torque transmitted from the vibration damping control unit; and a torque control unit that controls the motor based on the torque after limiting processing transmitted from the second limiting unit.

[0010] Embodiment 2. In Embodiment 1 above, it is preferable that the setting unit sets the margin using a map that has the characteristic that the margin increases as the absolute value of the motor's required torque increases, and the margin increases as the absolute value of the motor's rotational speed increases. Embodiment 3. In Embodiment 1 above, it is preferable that the setting unit sets the margin to be larger as the difference between the short-time SOP and the long-time SOP of the battery increases, and sets the margin to be smaller as the difference decreases.

[0011] Embodiment 4. In any one of embodiments 1 to 3 described above, it is preferable that the vehicle is equipped with a generator for power generation in addition to the motor. In this case, it is preferable that the first limiting unit performs the limiting process with respect to the driver-requested torque using a value obtained by subtracting the generator-requested power generation from the first limiting power, and the second limiting unit performs the limiting process with respect to the adjusted torque using a value obtained by subtracting the generator-effective power generation from the second limiting power.

[0012] Embodiment 5. In any one of embodiments 1 to 3 above, it is preferable that the vehicle is a four-wheel drive vehicle equipped with a front motor and a rear motor for driving the front wheels and the rear wheels, respectively, and equipped with a front lower control device and a rear lower control device for controlling the front motor and the rear motor, respectively, as lower control devices. In this case, it is preferable that the control system is provided with a front setting unit as the setting unit for setting the margin for the front motor as the front margin and a rear setting unit for setting the margin for the rear motor as the rear margin, the first limiting power calculation unit calculates the first limiting power by subtracting the front margin and the rear margin from the initial power, and the second limiting power calculation unit is provided with a front calculation unit for calculating the second limiting power for the front motor and a rear calculation unit for calculating the second limiting power for the rear motor.

[0013] Furthermore, it is preferable that the front calculation unit calculates the second limiting power for the front motor by subtracting the rear motor's required power, which is obtained by converting the motor's required torque of the rear motor into power, from the value obtained by adding the front margin to the first limiting power, and that the rear calculation unit calculates the second limiting power for the rear motor by subtracting the front motor's required power, which is obtained by converting the motor's required torque of the front motor into power, from the value obtained by adding the rear margin to the first limiting power.

[0014] Embodiment 6. In Embodiment 5 described above, it is preferable that the vehicle is equipped with a generator for power generation in addition to the motor. In this case, it is preferable that one of the front lower control device and the rear lower control device is a combined lower control device that also has the function of controlling the generator, and that the first limiting unit performs the limiting process with respect to the driver-requested torque using a value obtained by subtracting the generator-requested power from the first limiting power. Furthermore, it is preferable that the front calculation unit or the rear calculation unit that transmits the second limiting power to the other of the front lower control device and the rear lower control device that is not the combined lower control device uses the value obtained by subtracting the generator-requested power from the first limiting power instead of the first limiting power, and that the second limiting unit of the combined lower control device performs the limiting process with respect to the adjusted torque using a value obtained by subtracting the generator-requested power from the second limiting power.

[0015] According to the disclosed vehicle control system, it is possible to achieve the torque intended by the driver while suppressing vibrations, and to fully utilize the performance of the battery while protecting it.

[0016] This is a schematic diagram showing the configuration of a vehicle to which the control system according to the first embodiment is applied. This is a block diagram of the control system according to the first embodiment. This is a diagram for explaining the operation of the control system according to the first embodiment. This is a block diagram of the control system according to the second embodiment. This is a block diagram of the control system according to the third embodiment. This is a schematic diagram showing the configuration of a vehicle to which the control system according to the fourth embodiment is applied. This is a block diagram of the control system according to the fourth embodiment.

[0017] A vehicle control system as an embodiment will be described with reference to the drawings. The embodiments shown below are merely illustrative, and there is no intention to exclude various modifications or applications of technologies not explicitly shown in the embodiments below. The configuration of each embodiment can be modified in various ways without departing from its spirit. Furthermore, it can be selected or combined as needed.

[0018] [1. Overview] The control system is installed in a vehicle (electric vehicle) equipped with a drive battery and a drive motor. In other words, the vehicle to which the control system is applied may be an electric vehicle (EV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV) that can run on the power of the drive battery. A plug-in hybrid vehicle means a hybrid vehicle that can be externally charged to the battery or receive power from the battery. Plug-in hybrid vehicles are provided with a charging port (inlet) for inserting a charging cable that receives power from an external charging facility, and an outlet for external power supply.

[0019] The control system includes a higher-level control unit and a lower-level control unit that can communicate with each other. The higher-level control unit is an electronic control unit (ECU) that integrates and controls various on-board devices, and is called, for example, an EV-ECU or PHEV-ECU. The lower-level control units are electronic control units (ECUs) provided for each on-board device, and include, for example, an MCU (Motor Control Unit) that controls the motor, a BMU (Battery Management Unit) that manages the battery, and a PDU (Power Drive Unit) that controls the motor and generator.

[0020] Both the higher-level and lower-level control units are electronic devices equipped with a processor and memory. A processor is a microprocessor such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit), while memory is such as ROM (Read Only Memory), RAM (Random Access Memory), or non-volatile memory. The control operations performed by each control unit are recorded and stored in memory as firmware or application programs. When a program is executed, its contents are loaded into memory space and executed by the processor.

[0021] The control system is configured to perform limiting processing (power limiting) that restricts the requested torque according to the battery's charge / dischargeable power (State of Power, hereinafter also referred to as "SOP"), and vibration damping control to suppress vibrations and shocks. Specifically, the higher-level control unit calculates the motor's requested torque by performing limiting processing on the driver's requested torque and transmits it to the lower-level control unit. Furthermore, the lower-level control unit performs vibration damping control by adjusting the motor's requested torque.

[0022] In the control system, a predetermined margin is taken into consideration when setting the limit value (limiting power) used in the limiting process at the higher-level control unit, and the lower-level control unit also performs limiting processing to limit the torque after vibration damping control according to the SOP. In other words, limiting processing is performed at both the higher-level and lower-level control units in the control system. Hereinafter, the limiting processing performed at the higher-level control unit will be referred to as the "first limiting processing," and the limiting processing performed at the lower-level control unit will be referred to as the "second limiting processing." Furthermore, the limit value used in the first limiting processing will be referred to as the "first limiting power," and the limit value used in the second limiting processing will be referred to as the "second limiting power."

[0023] The first limiting power is the maximum power the motor can use for acceleration or regeneration, and is the value obtained by subtracting a margin from the initial power corresponding to the SOP. The initial power may be the same as the SOP, or it may be the value obtained by subtracting the power consumption of auxiliary equipment (e.g., power consumption of the DC-DC converter, power consumption of the air conditioner, etc.) from the SOP, or it may be a corrected value obtained by multiplying the SOP by a predetermined coefficient. The second limiting power is the value obtained by adding a margin to the first limiting power, and is the same value as the initial power. In other words, in the first limiting process, the usable range of power is narrowed by the margin compared to the initial power, and the torque is limited, whereas in the second limiting process, the margin is added to (restored) the first limiting power, and the torque is limited within the usable range of the initial power.

[0024] Thus, the second limiting process performed by the lower-level control unit limits the torque after vibration control (power consumed or regenerated by the motor) even if it exceeds the usable range of the initial power, so that the power corresponding to the commanded torque finally instructed to the motor does not exceed the SOP (State of Power). This allows for the realization of the torque intended by the driver while suppressing vibration, and also protects the battery. Furthermore, because the second limiting process is performed in the lower-level control unit, the margin considered in the first limiting process in the higher-level control unit can be set to a smaller value. In other words, since there is no need to set a large margin in the higher-level control unit, the usable range of power can be utilized more effectively than before, and the performance of the battery can be fully utilized.

[0025] The control system described above will be explained in detail below with reference to four embodiments. The first embodiment describes a control system applicable to a vehicle equipped with one drive motor, the second embodiment describes a control system applicable to a vehicle in which a generator for power generation is added to the vehicle of the first embodiment, the third embodiment describes a control system applicable to a vehicle equipped with drive motors on both the front and rear sides, and the fourth embodiment describes a control system applicable to a vehicle in which a generator for power generation is added to the vehicle of the third embodiment.

[0026] [2. First Embodiment] [2-1. Vehicle Configuration] Figure 1 is a schematic diagram showing the configuration of a vehicle 9 to which the control system 1 according to the first embodiment is applied. As shown in Figure 1, the vehicle 9 is an electric vehicle (EV) equipped with a drive battery 2 and a drive motor 3.

[0027] Motor 3 is a motor-generator that combines the functions of both an electric motor and a generator. Motor 3 is a power source that exchanges power with battery 2, and mainly functions as an electric motor to drive vehicle 9, and functions as a generator during regeneration. Motor 3 may be a front motor (hereinafter referred to as "F motor") that drives the front wheels of vehicle 9, or a rear motor (hereinafter referred to as "R motor") that drives the rear wheels. An inverter (not shown) that converts DC current and AC current is provided near motor 3. The torque of motor 3 is controlled by the inverter to accelerate and decelerate vehicle 9.

[0028] Battery 2 is a secondary battery such as a lithium-ion secondary battery or a nickel-metal hydride battery. Battery 2 is set to have a maximum chargeable power [kW] and a maximum dischargeable power [kW]. Specifically, Battery 2 is set to have a short-time SOPin (maximum chargeable power for a short time), a long-time SOPin (maximum chargeable power for a long time), a short-time SOPout (maximum dischargeable power for a short time), and a long-time SOPout (maximum dischargeable power for a long time).

[0029] Short-time SOPin and short-time SOPout are the maximum power applied to charging and discharging, respectively, when the charging time and discharging time are less than or equal to a predetermined time (relatively short time). The scale of the predetermined time to which short-time SOPin and short-time SOPout apply is assumed to be, for example, a few seconds. On the other hand, long-time SOPin and long-time SOPout are the maximum power applied to charging and discharging, respectively, when the charging time and discharging time exceed a predetermined time, and their values ​​are set to be smaller than short-time SOPin and short-time SOPout. Long-time SOPin and long-time SOPout are parameters that can correspond to, for example, the rated output power of a typical battery 2.

[0030] The values ​​for short-time SOPin, short-time SOPout, long-time SOPin, and long-time SOPout may be fixed values ​​set in advance, or they may be variable values ​​set according to the operating state of the battery 2 (charge state, SOH, current value, voltage value, temperature, etc.) and the driving state of the vehicle 9 (driving mode, vehicle speed, outside temperature, accelerator opening, etc.). Similarly, the predetermined time during which short-time SOPin and short-time SOPout can be used may also be a fixed value set in advance, or it may be a variable value set according to the operating state of the battery 2 and the driving state of the vehicle 9.

[0031] Vehicle 9 is equipped with an accelerator pedal position sensor 71, a brake sensor 72, a shift position sensor 73, a vehicle speed sensor 74, a motor rotation speed sensor 75, a voltage sensor 76, a current sensor 77, and a temperature sensor 78. The accelerator pedal position sensor 71 detects the accelerator pedal's depression operation (such as accelerator pedal position and accelerator pedal depression speed), and the brake sensor 72 detects the brake pedal's depression operation (such as whether or not the brakes are applied and the amount of depression). The shift position sensor 73 detects the shift position, and the vehicle speed sensor 74 detects the vehicle speed. The motor rotation speed sensor 75 is a sensor such as a resolver or encoder, and detects the rotation speed of the rotor relative to the stator of the motor 3. The voltage sensor 76 detects the voltage of the battery 2, the current sensor 77 detects the input and output current of the battery 2, and the temperature sensor 78 detects the temperature of the battery 2. Note that other sensors may be provided in vehicle 9.

[0032] Vehicle 9 is equipped with a higher-level control unit 10 (EV-ECU, hereinafter referred to as "higher-level ECU 10") and lower-level control units, MCU 20 and BMU 60. The control system 1 includes the higher-level ECU 10, MCU 20, and BMU 60. The higher-level ECU 10, MCU 20, and BMU 60 are connected to each other by high-speed communication means such as local CAN or hardwire, enabling the transmission and reception of information.

[0033] In addition to the MCU 20 and BMU 60, the input side of the higher-level ECU 10 is connected to an accelerator position sensor 71, a brake sensor 72, a shift position sensor 73, and a vehicle speed sensor 74. The output side of the higher-level ECU 10 is connected to at least the MCU 20, and may also be connected to the BMU 60. Sensors and other lower-level control devices (not shown) may be connected to the input side of the higher-level ECU 10, and other lower-level control devices and in-vehicle equipment may be connected to the output side of the higher-level ECU 10.

[0034] The MCU 20 controls the motor 3, and in this embodiment, the MCU 20 has a built-in inverter. The input side of the MCU 20 is connected to the higher-level ECU 10 and the motor rotation speed sensor 75, and the output side of the MCU 20 is connected to at least the higher-level ECU 10 and the motor 3. The BMU 60 manages and controls the state of the battery 2, and the input side of the higher-level ECU 10, voltage sensor 76, current sensor 77, and temperature sensor 78 are connected, and the output side of the BMU 60 is connected to at least the higher-level ECU 10. Sensors and other lower-level control devices (not shown) may be connected to the input side of the MCU 20 and BMU 60, and other lower-level control devices and other in-vehicle equipment may be connected to the output side of the MCU 20 and BMU 60.

[0035] [2-2. System Configuration] Figure 2 is a block diagram of the control system 1 of this embodiment. The upper-level ECU 10 is provided with a driver request torque calculation unit 11, a first limiting power calculation unit 12, a first limiting unit 13, a motor request torque calculation unit 14, a setting unit 15, and a second limiting power calculation unit 16. The MCU 20 is provided with a vibration damping control unit 21, a rotation speed detection unit 22, a second limiting unit 23, and a torque control unit 24. These functional elements may be realized by electronic circuits (hardware), programmed as software, or some of these functions may be provided as hardware and the others as software.

[0036] First, the functional elements of the higher-level ECU 10 will be explained. The driver-requested torque calculation unit 11 calculates the driver-requested torque Td using a known method based on the driver's operation of the vehicle 9 (for example, accelerator operation, brake operation, shift position). In addition, information other than driver operation (for example, vehicle speed, driving mode, etc.) may be taken into consideration when calculating the driver-requested torque Td. The driver-requested torque calculation unit 11 transmits the calculated driver-requested torque Td to the first limiting unit 13.

[0037] The first power limiting calculation unit 12 calculates the first power limiting Pt1 and transmits the calculated value Pt1 to the first limiting unit 13 and the second power limiting calculation unit 16. Specifically, the first power limiting calculation unit 12 determines the initial power Pi according to the charge / dischargeable power (SOP) of the battery 2, and calculates the first power limiting Pt1 as the value obtained by subtracting a predetermined margin M from this initial power Pi (= Pi - M). The SOP is calculated by the BMU 60 using a known method based on the voltage, current, remaining charge, temperature, etc., of the battery 2, and is transmitted to the higher-level ECU 10 and then transmitted to the first power limiting calculation unit 12. If the initial power Pi is the value obtained by subtracting the auxiliary power consumption from the SOP, the higher-level ECU 10 can obtain the voltage and current values ​​of the auxiliary equipment, and the first power limiting calculation unit 12 can calculate the auxiliary power consumption. The margin M is transmitted from the setting unit 15, which will be described later.

[0038] The first limiting unit 13 performs a limiting process (first limiting process) on the driver requested torque Td transmitted from the driver requested torque calculation unit 11 using the first limiting power Pt1 transmitted from the first limiting power calculation unit 12. The motor rotation speed N transmitted from the MCU 20 (described later) to the higher-level ECU 10 is transmitted to the first limiting unit 13. In the first limiting process, the first limiting power Pt1 is converted to torque by dividing the first limiting power Pt1 by the motor rotation speed N, and the converted torque (hereinafter referred to as "first limiting torque") is compared with the driver requested torque Td. If driver requested torque Td > first limiting torque, the driver requested torque Td is limited by the first limiting torque. In this case, the first limiting unit 13 transmits the first limiting torque to the motor requested torque calculation unit 14 as the torque Tt1 after the first limiting process. On the other hand, if driver requested torque Td ≤ first limiting torque, the driver requested torque Td is not limited. In this case, the first limiting unit 13 transmits the driver-requested torque Td as the torque Tt1 after the first limiting process to the motor-requested torque calculation unit 14.

[0039] The motor request torque calculation unit 14 calculates the motor request torque Tm based on the torque Tt1 after the first limiting process transmitted from the first limiting unit 13. The motor request torque Tm may be calculated, for example, by dividing the torque Tt1 after the first limiting process by a reduction ratio (gear ratio), depending on a reduction mechanism or gear mechanism interposed in the power transmission path from the motor 3 to the drive wheels. The motor request torque calculation unit 14 transmits the calculated motor request torque Tm to the setting unit 15 and also transmits it to the MCU 20.

[0040] The setting unit 15 sets a margin M and transmits the set margin M to the first limiting power calculation unit 12 and the second limiting power calculation unit 16. As described above, the margin M is used in the calculation of the first limiting power Pt1 and is a value (SOP margin value) that provides a margin in the power range that the motor 3 can use relative to the SOP. The margin M is also used in the calculation of the second limiting power Pt2, which will be described later. The margin M may be a variable value set using, for example, a map or a mathematical formula, or it may be a fixed value set in advance. If the margin M is a variable value, the following setting methods can be used as an example.

[0041] Setting Method 1: Set the margin M using a map that has the characteristic that the margin M increases as the absolute value of the motor required torque Tm increases, and the margin M increases as the absolute value of the motor rotation speed N increases. Setting Method 2A: When motor 3 is in the powering state, set the margin M to be larger the greater the difference between the short-time SOPout and the long-time SOPout of battery 2, and set the margin M to be smaller the smaller this difference is. Setting Method 2B: When motor 3 is in the regenerative state, set the margin M to be larger the greater the difference between the short-time SOPin and the long-time SOPin of battery 2, and set the margin M to be smaller the smaller this difference is.

[0042] In setting method 1, the setting unit 15 only needs to set a power value corresponding to the torque added by the vibration damping control unit 21. For example, a map is pre-stored in which the motor request torque Tm is plotted on the horizontal axis and the motor rotation speed N is plotted on the vertical axis, and a margin M is set according to these two parameters Tm and N. The setting unit 15 then sets the margin M by applying the motor request torque Tm transmitted from the motor request torque calculation unit 14 and the motor rotation speed N from the MCU 20 to the map. Note that the block diagram shown in Figure 2 illustrates the case when setting method 1 is adopted. In this method, as shown in Figure 2, the motor rotation speed N transmitted from the MCU 20 to the higher-level ECU 10 is transmitted to the setting unit 15.

[0043] In setting methods 2A and 2B, the setting unit 15 calculates the difference using the short-time SOPin, short-time SOPout, long-time SOPin, and long-time SOPout transmitted from the BMU 60, depending on whether the motor 3 is in a powering state or a regenerative state, and sets the margin M according to that difference. The state of the motor 3 (powering state, regenerative state) may be determined by the setting unit 15 or by other functional elements of the higher-level ECU 10. In this method, the values ​​of short-time SOPin, short-time SOPout, long-time SOPin, and long-time SOPout are transmitted from the BMU 60 to the higher-level ECU 10 and then transmitted to the setting unit 15.

[0044] The second limited power calculation unit 16 calculates a value (=Pt1+M) obtained by adding the margin M transmitted from the setting unit 15 to the first limited power Pt1 transmitted from the first limited power calculation unit 12 as the second limited power Pt2, and transmits the calculated value Pt2 to the MCU 20. This second limited power Pt2 has the same value as the initial power Pi, as described above.

[0045] Next, functional elements of the MCU 20 will be described. The damping control unit 21 implements damping control by adjusting the motor required torque Tm received from the motor required torque calculation unit 14. In damping control, for example, the amount of change in torque is limited, or torque is periodically increased or decreased to cancel vibration at a specific motor rotation speed N. Conventional control methods can be adopted for damping control, and detailed description thereof will be omitted. The damping control unit 21 transmits the motor required torque Tm after damping control as the adjusted torque Tv to the second limiting unit 23.

[0046] The rotation speed detection unit 22 detects the motor rotation speed N, transmits the detected value N to the second limiting unit 23, and also transmits the value N to the host ECU 10. When the vehicle 9 is provided with a motor rotation speed sensor 75, the rotation speed detection unit 22 may detect a value detected by the motor rotation speed sensor 75 or a corrected value of this value as the motor rotation speed N. Further, when the motor rotation speed sensor 75 is not provided, the rotation speed detection unit 22 may detect the motor rotation speed N by estimating it based on the voltage value and current value of the motor 3.

[0047] It should be noted that the motor rotation speed N transmitted from the rotation speed detection unit 22 to the second limiting unit 23 is a real-time value (a value with no communication delay and no low-pass filter processing), whereas the motor rotation speed N transmitted from the rotation speed detection unit 22 to the host ECU 10 is a value that has communication delay and has been subjected to low-pass filter processing. For this reason, the processing (conversion accuracy) in the second limiting unit 23, which will be described later, has higher accuracy than the processing (conversion accuracy) in the first limiting unit 13 described above.

[0048] The second limiting unit 23 performs a limiting process (second limiting process) on the adjusted torque Tv transmitted from the vibration damping control unit 21 by using the second power limit Pt2 received from the second power limit calculation unit 16. In the second limiting process, the second power limit Pt2 is divided by the motor rotation speed N transmitted from the rotation speed detection unit 22 to be converted into torque, and the adjusted torque Tv is compared with the converted torque (hereinafter referred to as "second limiting torque"). If the adjusted torque Tv > the second limiting torque, the adjusted torque Tv is limited by the second limiting torque. In this case, the second limiting unit 23 transmits the second limiting torque to the torque control unit 24 as the torque Tt2 after the second limiting process. On the other hand, if the adjusted torque Tv ≤ the second limiting torque, the adjusted torque Tv is not limited. In this case, the second limiting unit 23 transmits the adjusted torque Tv to the torque control unit 24 as the torque Tt2 after the second limiting process.

[0049] The torque control unit 24 controls the torque of the motor 3 based on the torque Tt2 after the second limiting process transmitted from the second limiting unit 23. The torque control unit 24 controls the torque of the motor 3, for example, by performing switching control of an inverter. In the control system 1, for example, when the main power supply of the vehicle 9 is on, the various processes described above are repeatedly executed at a predetermined calculation cycle.

[0050] [2-3. Operation] Figure 3 is a diagram for explaining the operation of the control system 1 according to the present embodiment. In FIG. 3, since a case where the motor 3 is in a regenerative state is illustrated, all torques in the diagram are negative values. As shown by the thick solid line in the diagram, the motor demand torque Tm is limited by the first limiting torque obtained by converting the first power limit Pt1 into torque, so it is set to a value that does not fall below the first limiting torque (in other words, a value where the absolute value of Tm is less than or equal to the absolute value of the first limiting torque). The first limiting torque is a value obtained by adding a margin M to the second limiting torque (a value obtained by converting the second power limit Pt2 into torque), whereby in the first limiting process, the usable range of power is narrowed by the amount of the margin M.

[0051] The adjusted torque Tv, shown by the thick dashed line in the figure, is the result of the motor request torque Tm being adjusted in the vibration damping control unit 21, and changes in proportion to the motor request torque Tm, for example as shown in the figure. For this reason, the adjusted torque Tv may fall below the first limiting torque (exceed on the negative side), and may even fall below the second limiting torque. However, in the control system 1 of this embodiment, a limiting process (second limiting process) is also performed in the MCU 20, and the adjusted torque Tv is limited by the second limiting torque. For this reason, the portion with a dotted pattern in the figure (the portion where the adjusted torque Tv falls below the second limiting torque) is limited by the second limiting torque and is output (instructed) to the motor 3 as the torque Tt2 after the second limiting process, as shown by the thick dotted line in the figure.

[0052] In this way, by performing another limiting process (second limiting process) after torque adjustment by vibration damping control, the torque instructed to the motor 3 (torque Tt2 after the second limiting process) is prevented from exceeding the torque limited according to the SOP (second limiting torque). Furthermore, the second limiting power Pt2 (second limiting torque) used in the second limiting process is the first limiting power Pt1 (first limiting torque) used in the first limiting process with a margin M added (restored). For this reason, the second limiting process can implement power limiting with a wider range of usable power than the first limiting process, thus avoiding unnecessary restrictions.

[0053] In addition, due to the second limiting process, even if the adjusted torque Tv falls below the second limiting torque, the portion below that limit is limited by the second limiting torque. Therefore, in the first limiting process, it is not necessary to set a larger margin (comparative example) as shown by the thin dashed line in the figure.

[0054] As shown in the comparative example, when a larger margin is set, the motor's required torque (comparative example) is set so as not to fall below this comparative example's margin, as indicated by the thin dashed line in the figure. In this case, when torque adjustment is performed by vibration damping control, it is possible to prevent the actual torque (comparative example) from falling below the power limiting torque, as indicated by the thin dotted line in the figure. However, in this case, the usable range of power from battery 2 becomes limited, and the performance of battery 2 cannot be fully utilized. This situation is avoided by the control system 1 of this embodiment.

[0055] [2-4. Effects] In the control system 1 described above, the motor request torque Tm calculated by the higher-level ECU 10 is based on the torque after a limiting process (first limiting process) has been performed with a first limiting power Pt1, which is obtained by subtracting a margin M from the initial power Pi corresponding to the SOP. Furthermore, the MCU 20 performs another limiting process (second limiting process) on the adjusted torque Tv transmitted from the vibration damping control unit 21. In this second limiting process, a second limiting power Pt2 (i.e., the initial power Pi before subtracting the margin M from the first limiting power Pt1) is used, which is the first limiting power Pt1 plus a margin M.

[0056] Therefore, in the second limiting process in the MCU 20, even if the torque is adjusted by vibration damping control and exceeds the second limiting power Pt2, it will be limited by the second limiting power Pt2, so that the power corresponding to the torque instructed from the torque control unit 24 to the motor 3 will not exceed SOP. Furthermore, since the margin M can be set to the minimum size in the higher-level ECU 10, the usable range of power can be utilized more effectively than before. As a result, the characteristics (performance) of the battery 2 can be utilized, thereby extending the EV range and improving energy efficiency. Accordingly, the control system 1 described above can achieve the torque intended by the driver while suppressing vibrations, and can fully utilize the performance of the battery 2 while protecting it.

[0057] When the setting unit 15 described above sets the margin M according to setting method 1, it can set an appropriate margin M based on the information from the motor 3. This makes it easier to achieve the torque intended by the driver while suppressing vibrations. The vibration control unit 21 can apply a larger torque the greater the degree of vibration, but setting a larger margin M in the torque and rotational speed range where vibrations are likely to occur makes it easier to suppress vibrations. Conversely, setting a smaller margin M in the torque and rotational speed range where vibrations are less likely to occur can extend the EV range and improve energy efficiency.

[0058] On the other hand, when the setting unit 15 described above sets the margin M using setting methods 2A and 2B, it can set an appropriate margin M based on the information from the battery 2. This allows for better protection of the battery 2 while further utilizing its performance. Since the torque adjustment time required for vibration suppression is short, the difference between the short-time SOP and the long-time SOP can be allocated to the torque adjustment, allowing the long-time SOP to be directly allocated to the drive torque. Therefore, a stable propulsion force for the vehicle 9 can be obtained without reducing the drive torque relative to the long-time SOP.

[0059] [3. Second Embodiment] Figure 4 is a block diagram showing the control system 1A of the second embodiment. As described above, the control system 1A of the second embodiment differs from the control system 1 of the first embodiment in that a generator (not shown) for power generation is provided in the vehicle (not shown), but the basic configuration is the same. Below, the configuration that differs from the first embodiment will be mainly described, and for configurations and parameters common to the first embodiment, the same reference numerals or reference numerals with an alphabet added to the end will be used, and redundant explanations will be omitted.

[0060] In a vehicle to which the control system 1A of this embodiment is applied, a generator for power generation and a drive source (not shown, for example, an engine) for driving the generator are provided separately from the motor 3. The generator is connected to the drive source and can operate independently of the operating state of the motor 3. The generator may have only the function of a generator, or it may be a motor-generator (motor generator) that combines the functions of an electric motor and a generator. The electricity generated by the generator is used to charge the battery 2. In other words, in the vehicle of this embodiment, the drive source drives the generator to generate electricity, thereby enabling the battery 2 to be charged. An inverter (not shown) for converting DC current to AC current is provided near the generator.

[0061] As shown in Figure 4, the control system 1A includes a PDU 30 instead of the MCU 20 described above. The PDU 30 is a lower-level control device that can communicate with the higher-level ECU 10A, and in addition to having the function of controlling the motor 3 (the same function as the MCU 20), it also has the function of controlling the generator and has a built-in inverter for the generator.

[0062] In this embodiment, the higher-level ECU 10A calculates the power to be generated by the generator (hereinafter referred to as "requested power generation PGd") based on information about the battery 2 (voltage, current, remaining charge, temperature) transmitted from the BMU 60, as well as vehicle speed and driving mode. The higher-level ECU 10A transmits the requested torque Tg (not shown), obtained by dividing the calculated requested power generation PGd by the generator rotation speed Ng (not shown), to the PDU 30, and the PDU 30 controls the torque of the generator. The actual power generated by the generator (hereinafter referred to as "effective power generation PGe") is determined by the PDU 30. Note that both the requested power generation PGd and the effective power generation PGe are negative values.

[0063] In the higher-level ECU 10A of this embodiment, the requested power generation power PGd is subtracted from the first limiting power Pt1 calculated by the first limiting power calculation unit 12, and this subtracted value Pt1' (= Pt1 - PGd) is transmitted to the first limiting unit 13A. Therefore, the first limiting unit 13A performs the first limiting process on the driver requested torque Td transmitted from the driver requested torque calculation unit 11 using this subtracted value Pt1'. The content of the first limiting process is the same as the first limiting process described in the first embodiment, but with the "first limiting power Pt1" replaced by the "subtracted value Pt1'".

[0064] Thus, the limit value (subtraction value Pt1') used in the first limiting process is the value obtained by subtracting the generator's required power generation PGd from the first limiting power Pt1 (since a negative value is subtracted, this is the value obtained by adding the absolute value of PGd to Pt1). As a result, the usable range of power is expanded by the amount of the required power generation PGd compared to the limit value (first limiting power Pt1) in the first embodiment. The value input to the second limiting power calculation unit 16 is the first limiting power Pt1, as in the first embodiment. Furthermore, the other configurations of the higher-level ECU 10 are the same as in the first embodiment.

[0065] The PDU 30 is equipped with a vibration damping control unit 31, a rotation speed detection unit 32, a second limiting unit 33, and a torque control unit 34. These functional elements may be implemented by electronic circuits (hardware), programmed as software, or some of these functions may be provided as hardware and the others as software. The vibration damping control unit 31, rotation speed detection unit 32, and torque control unit 34 are identical to the vibration damping control unit 21, rotation speed detection unit 22, and torque control unit 24 provided in the MCU 20, respectively.

[0066] In the PDU 30 of this embodiment, the effective power generation power PGe is subtracted from the second limiting power Pt2 calculated by the second limiting power calculation unit 16, and this subtracted value Pt2' (= Pt2 - PGe) is transmitted to the second limiting unit 33. Therefore, the second limiting unit 33 performs a second limiting process on the adjusted torque Tv transmitted from the vibration control unit 31 using this subtracted value Pt2'. The content of the second limiting process is the same as the second limiting process described in the first embodiment, but with the "second limiting power Pt2" replaced by the "subtracted value Pt2'".

[0067] Thus, the limit value used in the second limiting process (subtraction value Pt2') is the value obtained by subtracting the effective power generated by the generator PGe from the second limiting power Pt2 (since a negative value is subtracted, this is the value obtained by adding the absolute value of PGe to Pt2). Compared to the limit value (second limiting power Pt2) in the first embodiment, the usable range of power that the motor 3 can use for propulsion is widened by the amount of the effective power generated PGe. If the motor 3 is regenerative, the usable range of power is narrowed.

[0068] In the case of a vehicle equipped with a generator, as in this embodiment, the first and second limiting processes are performed using limiting values ​​(subtraction values ​​Pt1', Pt2') that take into account the power generated by the generator, thereby appropriately limiting (power limiting) the torque instructed to the motor 3. Therefore, the control system 1A of this embodiment can achieve the torque intended by the driver while suppressing vibrations, and can fully utilize the performance of the battery 2 while protecting it.

[0069] Furthermore, the power generated by the generator is closer to the actual value when using the effective power generation power PGe than when using the required power generation power PGd. In particular, regarding rotational speed detection, the value of PDU 30 is more accurate for the generator as well, similar to motor 3. Therefore, by using the effective power generation power PGe in the second limiting process performed by PDU 30, the second limiting process can be performed with higher accuracy. In addition, the control system 1A of this embodiment can obtain the same effects as the first embodiment from the same configuration.

[0070] [4. Third Embodiment] Figure 5 is a block diagram showing the control system 1B of the third embodiment. As described above, the control system 1B of the third embodiment differs from the control system 1 of the first embodiment in that it is provided with drive motors (F motor, R motor) not shown on the front and rear sides of the vehicle (not shown). The basic concept is the same as the first embodiment, but in this embodiment, the margin M, the first limiting power Pt1, and the second limiting power Pt2 of the first embodiment are set and calculated separately for the front and rear sides, respectively. The following will mainly describe the configurations that differ from the first embodiment, and for configurations and parameters that are common with the first embodiment, the same reference numerals or reference numerals with an alphabet added to the end will be used, and redundant explanations will be omitted.

[0071] A vehicle to which the control system 1B of this embodiment is applied is equipped with an F motor for driving the front wheels and an R motor for driving the rear wheels. Both the front and rear motors (F motor and R motor) may be configured in the same way as the motor 3 described above. A front inverter (not shown) is provided near the F motor, and a rear inverter (not shown) is provided near the R motor.

[0072] As shown in Figure 5, the control system 1B includes an FMCU 40 and an RMCU 50, which have functions similar to the MCU 20 described above. Both the FMCU 40 and the RMCU 50 are lower-level control devices capable of communicating with the higher-level ECU 10B. The FMCU 40 (front lower-level control device) has the function of controlling the F motor and has a built-in inverter for the F motor. The RMCU 50 (rear lower-level control device) has the function of controlling the R motor and has a built-in inverter for the R motor.

[0073] The higher-level ECU 10B of this embodiment is equipped with the following functional elements: a driver-requested torque calculation unit 11, a first limiting power calculation unit 12B, a first limiting unit 13B, a motor-requested torque calculation unit 14B, a front setting unit 15F, a rear setting unit 15R, a front second limiting power calculation unit 16F, a rear second limiting power calculation unit 16R, a front conversion unit 17F, and a rear conversion unit 17R. In Figure 5, "front" is denoted as "F" and "rear" as "R".

[0074] The first limiting power calculation unit 12B calculates the limiting value (first limiting power Pt1) used in the first limiting process, similar to the first limiting power calculation unit 12 described above. However, the only difference in this calculation unit 12B is that it calculates the first limiting power Pt1 as the value obtained by subtracting the front margin Mf and rear margin Mr described later from the initial power Pi corresponding to the SOP (= Pi - Mf - Mr).

[0075] The first limiting unit 13B performs the first limiting process in the same manner as the first limiting unit 13 described above, and transmits the torque Tt1 after the first limiting process to the motor request torque calculation unit 14B. The first limiting unit 13B receives the front motor rotation speed Nf (hereinafter referred to as "FM rotation speed Nf") transmitted from the FMCU 40 to the higher-level ECU 10B, as well as the rear motor rotation speed Nr (hereinafter referred to as "RM rotation speed Nr") transmitted from the RMCU 50 to the higher-level ECU 10B. In the first limiting process, the first limiting power Pt1 is converted to torque by dividing it by at least one of the front and rear motor rotation speeds Nf and Nr. Then, the driver request torque Td is compared with the converted torque (first limiting torque). The subsequent processing is the same as in the first embodiment.

[0076] The motor request torque calculation unit 14B calculates the front motor request torque Tmf (hereinafter referred to as "FM request torque Tmf") and the rear motor request torque Tmr (hereinafter referred to as "RM request torque Tmr") based on the torque Tt1 after the first limiting process transmitted from the first limiting unit 13B. Each motor request torque Tmf and Tmr can be calculated, for example, by distributing the torque Tt1 after the first limiting process to the front and rear in a predetermined distribution. The distribution may be a fixed value or a variable value. The distribution may also be changed according to the front and rear motor rotation speeds Nf and Nr. The motor request torque calculation unit 14B transmits the calculated FM request torque Tmf to the front conversion unit 17F and also transmits it to the FMCU 40, and transmits the calculated RM request torque Tmr to the rear conversion unit 17R and also transmits it to the RMCU 50.

[0077] The front conversion unit 17F converts the FM requested torque Tmf into power by multiplying it by the FM rotation speed Nf transmitted from the FMCU 40. The front conversion unit 17F transmits the converted power (front motor requested power, hereinafter referred to as "FM requested power Pmf") to the rear second limiting power calculation unit 16R. The rear conversion unit 17R converts the RM requested torque Tmr into power by multiplying it by the RM rotation speed Nr transmitted from the RMCU 50. The rear conversion unit 17R transmits the converted power (rear motor requested power, hereinafter referred to as "RM requested power Pmr") to the front second limiting power calculation unit 16F.

[0078] The front setting unit 15F sets the margin for the F motor as the front margin Mf. The front margin Mf is a value (F motor margin value) that provides a margin in the power range that the F motor can use relative to the SOP. The rear setting unit 15R sets the margin for the R motor as the rear margin Mr. The rear margin Mr is a value (R motor margin value) that provides a margin in the power range that the R motor can use relative to the SOP.

[0079] Each setting unit 15F, 15R may be configured in the same way as the setting unit 15 of the first embodiment. That is, each setting unit 15F, 15R may set the respective margins Mf, Mr by setting method 1 or setting methods 2A and 2B described above. The block diagram shown in Figure 5 illustrates the case where setting method 1 is adopted. In this method, the FM rotation speed Nf and the FM required torque Tmf are input to the front setting unit 15F, and the RM rotation speed Nr and the RM required torque Tmr are input to the rear setting unit 15R. The front setting unit 15F transmits the set front margin Mf to the first limiting power calculation unit 12B and the front second limiting power calculation unit 16F. The rear setting unit 15R also transmits the set rear margin Mr to the first limiting power calculation unit 12B and the rear second limiting power calculation unit 16R.

[0080] The front second limiting power calculation unit 16F (front calculation unit) calculates the second limiting power Pt2f for the F motor. The second limiting power Pt2f is the value obtained by adding the front margin Mf to the first limiting power Pt1 and subtracting the RM required power Pmr, as shown in equation (1) below. The front second limiting power calculation unit 16F transmits the calculated second limiting power Pt2f to the FMCU 40. Pt2f = Pt1 + Mf - Pmr ... (1)

[0081] The rear second limiting power calculation unit 16R (rear calculation unit) calculates the second limiting power Pt2r for the R motor. The second limiting power Pt2r is the value obtained by adding the rear margin Mr to the first limiting power Pt1 and subtracting the FM required power Pmf, as shown in equation (2) below. The rear second limiting power calculation unit 16R transmits the calculated second limiting power Pt2r to the RMCU 50. Pt2r = Pt1 + Mr - Pmf ... (2)

[0082] As shown in equations (1) and (2) above, in each second limiting power calculation unit 16F and 16R, the second limiting power Pt2f for the F motor and the second limiting power Pt2r for the R motor are calculated by subtracting the motor demands of the front and rear motors on opposite sides (RM demanding power Pmr on the front side and FM demanding power Pmf on the rear side) from the total power limiting value (Pt1 + Mf or Pt1 + Mr).

[0083] The FMCU 40 is equipped with an F vibration damping control unit 41, an F rotation speed detection unit 42, an F second limiting unit 43, and an F torque control unit 44. The RMCU 50 is equipped with an R vibration damping control unit 51, an R rotation speed detection unit 52, an R second limiting unit 53, and an R torque control unit 54. These functional elements may be implemented by electronic circuits (hardware), programmed as software, or some of these functions may be provided as hardware and others as software.

[0084] The F vibration damping control unit 41 and R vibration damping control unit 51, the F rotation speed detection unit 42 and R rotation speed detection unit 52, the F second limiting unit 43 and R second limiting unit 53, the F torque control unit 44 and R torque control unit 54 are configured substantially the same as the vibration damping control unit 21, rotation speed detection unit 22, second limiting unit 23, and torque control unit 24 provided in the MCU 20, respectively. A brief explanation follows below.

[0085] The F vibration control unit 41 performs vibration control by adjusting the FM request torque Tmf received from the motor request torque calculation unit 14B. The F vibration control unit 41 transmits the FM request torque Tmf after vibration control as the adjusted torque Tvf to the F second limiting unit 43. The R vibration control unit 51 performs vibration control by adjusting the RM request torque Tmr received from the motor request torque calculation unit 14B. The R vibration control unit 51 transmits the RM request torque Tmr after vibration control as the adjusted torque Tvr to the R second limiting unit 53.

[0086] The F rotation speed detection unit 42 detects the FM rotation speed Nf and transmits the detected value Nf to the F second limiting unit 43 and also to the higher-level ECU 10B. The R rotation speed detection unit 52 detects the RM rotation speed Nr and transmits the detected value Nr to the R second limiting unit 53 and also to the higher-level ECU 10B.

[0087] The F second limiting unit 43 performs a limiting process (second limiting process) on the adjusted torque Tvf transmitted from the F vibration damping control unit 41 using the second limiting power Pt2f received from the front second limiting power calculation unit 16F. In the second limiting process, the second limiting power Pt2f is converted to torque by dividing it by the FM rotation speed Nf transmitted from the F rotation speed detection unit 42, and the adjusted torque Tvf and the converted torque (second limiting torque) are compared. If the adjusted torque Tvf > second limiting torque, the second limiting torque is transmitted to the F torque control unit 44 as the torque Tt2f after the second limiting process. Conversely, if the adjusted torque Tvf ≤ second limiting torque, the adjusted torque Tvf is transmitted to the F torque control unit 44 as the torque Tt2f after the second limiting process.

[0088] The R second limiting unit 53 performs a limiting process (second limiting process) on the adjusted torque Tvr transmitted from the R vibration damping control unit 51 using the second limiting power Pt2r received from the rear second limiting power calculation unit 16R. In the second limiting process, the second limiting power Pt2r is converted to torque by dividing it by the RM rotation speed Nr transmitted from the R rotation speed detection unit 52, and the adjusted torque Tvr and the converted torque (second limiting torque) are compared. If the adjusted torque Tvr > second limiting torque, the second limiting torque is transmitted to the R torque control unit 54 as the torque Tt2r after the second limiting process. Conversely, if the adjusted torque Tvr ≤ second limiting torque, the adjusted torque Tvr is transmitted to the R torque control unit 54 as the torque Tt2r after the second limiting process.

[0089] The F torque control unit 44 controls the F motor based on the torque Tt2f after the second limiting process transmitted from the F second limiting unit 43. The R torque control unit 54 controls the R motor based on the torque Tt2r after the second limiting process transmitted from the R second limiting unit 53.

[0090] As detailed above, in a four-wheel drive vehicle equipped with F motors and R motors, the higher-level ECU 10B calculates the driver-requested torque Td and the first limiting power Pt1 for the entire vehicle, and performs the first limiting process. Then, the lower-level control devices 40 and 50 perform the second limiting process separately for the front and rear, and calculate the torques Tt2f and Tt2r for controlling each motor. Therefore, the control system 1B of this embodiment can achieve the torque intended by the driver while suppressing vibrations, and can fully utilize the performance of the battery 2 while protecting it.

[0091] Furthermore, the control system 1B of this embodiment makes it possible to achieve both a reduction in computational load and controllability of the front and rear motors. In particular, regarding the second limiting powers Pt2f and Pt2r used in the second limiting processing of the lower-level control devices 40 and 50, the RM required torque Tmr is taken into account when calculating the second limiting power Pt2f for the F motor, and the FM required torque Tmf is taken into account when calculating the second limiting power Pt2r for the R motor, so that appropriate torque limiting (power limiting) can be achieved for the front and rear. In addition, since power limiting is performed while maintaining the front and rear torque distribution set in the motor required torque calculation unit 14B, it does not affect the steering stability of the vehicle. Furthermore, the control system 1B of this embodiment can obtain the same effects as the first embodiment from the same configuration.

[0092] [5. Fourth Embodiment] Figure 6 is a schematic diagram showing the configuration of a vehicle 9C to which the control system 1C according to the fourth embodiment is applied, and Figure 7 is a block diagram showing the control system 1C of this embodiment. As described above, the control system 1C of this embodiment differs from the control system 1B of the third embodiment in that a generator for power generation is added to the vehicle of the third embodiment, but the basic configuration is the same. Hereinafter, the configurations that differ from the first, second, and third embodiments will be mainly described, and for configurations and parameters common to the first, second, and embodiments, the same reference numerals or reference numerals with an alphabet added to the end will be used, and redundant explanations will be omitted.

[0093] As shown in Figure 6, vehicle 9C is a PHEV (Phone-Hit Electric Vehicle) equipped with a battery 2, a front motor 3F, a rear motor 3R, a generator 4, an engine 5, and a transaxle 6. The front motor 3F drives the front wheels, and the rear motor 3R drives the rear wheels. These may be configured identically to the front motor and rear motor of the third embodiment. The generator 4 may be configured identically to the generator of the second embodiment, is connected to the engine 5 as a drive source, and is capable of operating independently of the operating states of the front motor 3F and rear motor 3R. In this embodiment, the generator 4 and engine 5 are located at the front.

[0094] The front wheels (drive wheels) are connected in parallel to the F motor 3F and the engine 5 via the transaxle 6, and the power from the F motor 3F and the engine 5 is transmitted individually. In addition, the engine 5 is connected in parallel to the generator 4 and the front wheels via the transaxle 6, and the power from the engine 5 is transmitted to the generator 4 in addition to the front wheels. The transaxle 6 is a power transmission device that integrates a final drive (final reduction gear) including a differential gear and a transmission (reduction gear), and incorporates multiple mechanisms that are responsible for power transmission between the drive source and the driven device.

[0095] Vehicle 9C is further equipped with a higher-level ECU 10C (PHEV-ECU), a lower-level control unit PDU 30C and RMCU 50, and the sensors 71-78 mentioned above. Motor rotation speed sensors 75 are provided for both the F motor 3F and the R motor 3R. Control system 1C includes the higher-level ECU 10C, PDU 30C, RMCU 50, and BMU 60, as shown in Figure 7.

[0096] PDU 30C is an example of a front lower control unit located at the front. Similar to the second embodiment, PDU 30C has the function of controlling the F motor 3F in addition to the function of controlling the generator 4, and incorporates the inverters for the F motor 3F and the generator 4. RMCU 50 is an example of a rear lower control unit located at the rear, and may be configured identically to the RMCU 50 of the third embodiment. In this embodiment, PDU 30C, as the front lower control unit, is a combined lower control unit that also has the function of controlling the generator 4.

[0097] In this embodiment, the higher-level ECU 10C, similar to the higher-level ECU 10A in the second embodiment, calculates the required power generation PGd of the generator 4, transmits the calculated value PGd to the PDU 30C, and the PDU 30C controls the generator 4. Also, similar to the second embodiment, the effective power generation PGe of the generator 4 is determined by the PDU 30C.

[0098] The higher-level ECU 10C of this embodiment is equipped with the following functional elements: a driver-requested torque calculation unit 11, a first limiting power calculation unit 12C, a first limiting unit 13C, a motor-requested torque calculation unit 14C, a front setting unit 15F, a rear setting unit 15R, a front second limiting power calculation unit 16F, a rear second limiting power calculation unit 16RC, a front conversion unit 17F, and a rear conversion unit 17R. Of these functional elements, the first limiting unit 13C and the rear second limiting power calculation unit 16RC differ from those provided in the higher-level ECU 10B of the third embodiment.

[0099] Furthermore, in the higher-level ECU 10C of this embodiment, similar to the second embodiment, the requested power generation PGd is subtracted from the first limiting power Pt1 calculated by the first limiting power calculation unit 12C, and this subtracted value Pt1' (= Pt1 - PGd) is transmitted to the first limiting unit 13C. The first limiting unit 13C performs the first limiting process on the driver's requested torque Td using this subtracted value Pt1', similar to the second embodiment.

[0100] In the upper-level ECU 10C, the first limiting power Pt1 is transmitted to the front second limiting power calculation unit 16F, similar to the third embodiment, but the difference from the third embodiment is that the subtracted value Pt1' is transmitted to the rear second limiting power calculation unit 16RC. In other words, the rear second limiting power calculation unit 16RC (rear calculation unit) calculates the rear second limiting power Pt2r using the subtracted value Pt1', which is obtained by subtracting the required generated power PGd from the first limiting power Pt1, instead of the first limiting power Pt1.

[0101] The PDU 30C is equipped with an F vibration damping control unit 31C, an F rotation speed detection unit 32C, an F second limiting unit 33C, and an F torque control unit 34C. The F vibration damping control unit 31C, the F rotation speed detection unit 32C, and the F torque control unit 34C are identical to the F vibration damping control unit 41, the F rotation speed detection unit 42, and the F torque control unit 44 provided in the FMCU 40 of the third embodiment, respectively. Furthermore, the F second limiting unit 33C corresponds to a combination of the functions of the second limiting unit 33 of the second embodiment and the functions of the F second limiting unit 43 of the third embodiment.

[0102] In the PDU 30C of this embodiment, the effective generated power PGe is subtracted from the second limiting power Pt2f calculated by the front second limiting power calculation unit 16F, and this subtracted value Pt2f' (= Pt2f - PGe) is transmitted to the F second limiting unit 33C. Therefore, the F second limiting unit 33C performs a second limiting process on the adjusted torque Tvf transmitted from the F vibration control control unit 31C using this subtracted value Pt2f'.

[0103] In the second limiting process of this embodiment, the subtracted value Pt2f' (= Pt2f - PGe) is converted to torque by dividing it by the FM rotation speed Nf transmitted from the F rotation speed detection unit 32C, and the adjusted torque Tvf is compared with the converted torque (second limiting torque). If the adjusted torque Tvf > second limiting torque, the second limiting torque is transmitted to the F torque control unit 34C as the torque Tt2f after the second limiting process. Conversely, if the adjusted torque Tvf ≤ second limiting torque, the adjusted torque Tvf is transmitted to the F torque control unit 34C as the torque Tt2f after the second limiting process.

[0104] As detailed above, in a four-wheel drive vehicle equipped with a generator for power generation in addition to the F motor and R motor, the higher-level ECU 10C calculates the driver-requested torque Td and the first limiting power Pt1 for the entire vehicle, and also calculates a limiting value (subtraction value Pt1') that takes into account the power generated by the generator 4. Then, in the first limiting process performed by the higher-level ECU 10C, this subtraction value Pt1' is used, so that appropriately power-limited motor-requested torques Tmf and Tmr can be calculated.

[0105] In addition, in the lower control devices 30C and 50, a second limiting process is performed separately for the front and rear, and then the torques Tt2f and Tt2r for controlling each motor 3F and 3R are calculated. Therefore, even with the control system 1C of this embodiment, it is possible to achieve the torque intended by the driver while suppressing vibrations, and to fully utilize the performance of the battery 2 while protecting it.

[0106] Furthermore, the effective power generated by the generator 4, PGe, is closer to the actual value than the required power generated PGd. Therefore, by using the effective power generated PGe in the second limiting process performed by the PDU 30C, the second limiting process can be performed with higher accuracy. In addition, the control system 1C of this embodiment can obtain the same effects as the first embodiment from the same configuration.

[0107] [6. Others] The control systems 1, 1A, 1B, and 1C of each embodiment described above are all examples and are not limited to the configurations described above. Also, the vehicles 9 and 9C to which the control systems 1 and 1C are applied are not limited to the configurations shown in Figures 1 and 6.

[0108] For example, in a vehicle to which the control systems 1 and 1A of the first and second embodiments are applied, one motor 3 is provided on either the front or rear side. However, two motors (left and right) may be provided on either the front or rear side. That is, the same control system as in the first and second embodiments may be applied to a vehicle in which left and right motors 3 drive the drive wheels on either the front or rear side. In this case, the control system includes two MCUs 20 that control the left and right motors 3, and can be applied by replacing "front" and "rear" with "left" and "right," respectively, in the control system 1B described in the third embodiment. In this vehicle, a mechanism may be provided that can apply a torque difference to the left and right drive wheels driven by the left and right motors 3.

[0109] Furthermore, in the fourth embodiment described above, the generator 4 and engine 5 are located on the front side of the vehicle 9C, but the generator 4 and engine 5 (or a drive source replacing the engine 5) may be located on the rear side of the vehicle. In this case, the RMCU (rear lower control unit) that controls the R motor 3R becomes a combined lower control unit that also has the function of controlling the generator 4, and the front lower control unit becomes an FMCU (for example, the same as the FMCU 40 in the third embodiment). In this case as well, in the upper ECU, the first limiting power Pt1 is transmitted to the rear second limiting power calculation unit, and the subtracted value Pt1' (= Pt1 - PGd) is transmitted to the front second limiting power calculation unit. In other words, the front second limiting power calculation unit (front calculation unit) calculates the front second limiting power Pt2r using the subtracted value Pt1' obtained by subtracting the required generated power PGd from the first limiting power Pt1, instead of the first limiting power Pt1. Even with such a configuration, the same effects as in the fourth embodiment described above can be obtained.

[0110] This technology can be used in the manufacturing industry of vehicles equipped with a drive battery and a drive motor.

[0111] 1, 1A, 1B, 1C Control System 2 Battery 3 Motor 3F Front Motor 3R Rear Motor 4 Generator 9, 9C Vehicle 10, 10A, 10B, 10C Higher-level ECU (Higher-level Control Unit) 11 Driver Request Torque Calculation Unit 12, 12B, 12C First Limiting Power Calculation Unit 13, 13A, 13B, 13C First Limiting Unit 14, 14B, 14C Motor Request Torque Calculation Unit 15 Setting Unit 15F Front Setting Unit 15R Rear Setting Unit 16 Second Limiting Power Calculation Unit 16F Front Limiting Power Calculation Unit (Front Calculation Unit) 16R, 16RC Rear Limiting Power Calculation Unit (Rear Calculation Unit) 20 MCU (Lower-level Control Unit) 21 Vibration Damping Control Unit 23 Second Limiting Unit 24 Torque Control Unit 30 PDU (Lower Control Unit, Front Lower Control Unit) 30C PDU (Lower Control Unit, Front Lower Control Unit, Combined Lower Control Unit) 40 FMCU (Lower Control Unit, Front Lower Control Unit) 50 RMCU (Lower Control Unit, Rear Lower Control Unit) 60 BMU (Lower Control Unit) M Margin Mf Front Margin Mr Rear Margin N Motor Speed ​​PGd Required Power Generation PGe Effective Power Generation Pi Initial Power Pmf FM Required Power (Front Motor Required Power) Pmr RM Required Power (Rear Motor Required Power) Pt1 First Limit Power Pt2 Second Limit Power Pt2f Second Limit Power for Front Motor Pt2r Second Limit Power for Rear Motor Pt2′, Pt2f′ Subtraction Value SOP Chargeable / Dischargeable Power Td Driver Required Torque Tm Motor Required Torque Tmf FM Required Torque (Front Motor Required Torque) Tmr RM Required Torque (Rear Motor Required Torque) Tt1 Torque after first limiting process: Tt2, Tt2f, Tt2r Torque after second limiting process: Tv, Tvf, Tvr Torque after adjustment

Claims

1. A control system provided in a vehicle equipped with a drive battery and a drive motor, including a higher-level control device and a lower-level control device that can communicate with each other, wherein the higher-level control device comprises: a first limiting power calculation unit that calculates a first limiting power, which is the maximum power usable by the motor for powering or regeneration, by subtracting a predetermined margin from an initial power corresponding to the chargeable / dischargeable power of the battery; a first limiting unit that performs limiting processing with the first limiting power on a driver-requested torque based on the driver operation of the vehicle; a motor-requested torque calculation unit that calculates a motor-requested torque based on the torque after limiting processing transmitted from the first limiting unit and transmits it to the lower-level control device; a setting unit that sets the margin; and a second limiting power calculation unit that transmits to the lower-level control device as a second limiting power, which is the first limiting power plus the margin, wherein the lower-level control device comprises: a vibration damping control unit that performs vibration damping control by adjusting the motor-requested torque; a second limiting unit that performs limiting processing with the second limiting power on an adjusted torque transmitted from the vibration damping control unit; and a torque control unit that controls the motor based on the torque after limiting processing transmitted from the second limiting unit, characterized in that the higher-level control device comprises 2. The vehicle control system according to claim 1, characterized in that the setting unit sets the margin using a map having the characteristic that the margin increases as the absolute value of the motor's required torque increases, and the margin increases as the absolute value of the motor's rotational speed increases.

3. The vehicle control system according to claim 1, characterized in that the setting unit sets the margin to be larger when the difference between the short-term SOP and the long-term SOP of the battery is large, and sets the margin to be smaller when the difference is small.

4. The vehicle is equipped with a generator for power generation in addition to the motor, the first limiting unit performs the limiting process with respect to the driver-requested torque using a value obtained by subtracting the generator-requested power generation from the first limiting power, and the second limiting unit performs the limiting process with respect to the adjusted torque using a value obtained by subtracting the generator-requested power generation from the second limiting power, characterized in that the vehicle is equipped with a generator for power generation in addition to the motor, the first limiting unit performs the limiting process with respect to the driver-requested torque using a value obtained by subtracting the generator-requested power generation from the second limiting power, the vehicle control system according to claim 1.

5. The vehicle is a four-wheel drive vehicle equipped with a front motor and a rear motor to drive the front wheels and the rear wheels respectively, and equipped with a front lower control device and a rear lower control device to control the front motor and the rear motor respectively, the setting unit is provided with a front setting unit that sets the margin for the front motor as the front margin, and a rear setting unit that sets the margin for the rear motor as the rear margin, the first limiting power calculation unit calculates the first limiting power by subtracting the front margin and the rear margin from the initial power, the second limiting power calculation unit is provided with a front calculation unit that calculates the second limiting power for the front motor, and a rear calculation unit that calculates the second limiting power for the rear motor, the front calculation unit calculates the second limiting power for the front motor by subtracting the rear motor required power, which is obtained by converting the motor required torque of the rear motor into power, from the value obtained by adding the front margin to the first limiting power, The vehicle control system according to claim 1, characterized in that the rear calculation unit calculates the second limiting power for the rear motor by subtracting the front motor's required power, which is obtained by converting the motor's required torque of the front motor into power, from the value obtained by adding the rear margin to the first limiting power.

6. The vehicle is equipped with a generator for power generation in addition to the motor, and one of the front lower control device and the rear lower control device is a combined lower control device that also has the function of controlling the generator, and the first limiting unit performs the limiting process with respect to the driver-requested torque using a value obtained by subtracting the generator-requested power from the first limiting power, and the front calculation unit or the rear calculation unit that transmits the second limiting power to the other of the front lower control device and the rear lower control device that is not the combined lower control device uses the value obtained by subtracting the generator-requested power from the first limiting power instead of the first limiting power, and the second limiting unit of the combined lower control device performs the limiting process with respect to the adjusted torque using a value obtained by subtracting the generator-requested power from the second limiting power, characterized in that the vehicle is equipped with a generator for power generation in addition to the motor, and one of the front lower control device and the rear lower control device is a combined lower control device.

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