Vehicle control device

Abstract

To improve fuel economy during unmanned automatic operation.SOLUTION: A vehicle control device 100 for controlling automatic operation of a vehicle V including a motor 22 includes: an inverter for driving the motor 22; and a controller for controlling unmanned automatic operation and manned automatic operation. The controller sets a switching frequency of the invertor to be lower than that during running manned automatic operation when a vehicle speed of the vehicle V is less than a determination threshold while running unmanned automatic operation.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] A control device for an electric vehicle is known that sets the switching frequency of a switching element that drives a motor higher than during normal control when the vehicle speed is low and the temperature of the switching element that drives the motor is low (see, for example, JP 2005-312279 A). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-312279 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is room for improvement in improving fuel efficiency during unmanned autonomous driving. The present invention provides a vehicle control device that can improve fuel efficiency during unmanned autonomous driving. [Means for solving the problem]

[0005] A vehicle control device according to one embodiment of the present invention is a vehicle control device that controls the automatic driving of a vehicle having a motor, and is equipped with an inverter that drives the motor, and a control unit that controls unmanned automatic driving and manned automatic driving, and when unmanned automatic driving is being performed, the control unit sets the switching frequency of the inverter lower than when manned automatic driving is being performed when the vehicle speed is below a judgment threshold. Effect of the Invention

[0006] According to one embodiment of the present invention, fuel efficiency can be improved during unmanned automatic driving. [Brief description of the drawings]

[0007] [Figure 1] 1 is a block diagram showing a vehicle control device according to an embodiment; [Diagram 2] 5 is a flowchart showing a process for setting a switching frequency when autonomous driving is performed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] The vehicle control device 100 according to this embodiment is mounted on a vehicle V equipped with a motor 22. The vehicle V is a vehicle capable of performing unmanned automatic driving and manned automatic driving. The vehicle V is an electric vehicle such as a HEV (Hybrid Electric Vehicle), a PHEV (Plug-in Hybrid Electric Vehicle), or a BEV (Battery Electric Vehicle). The vehicle V may be a BEV equipped with a motor 22 for driving but not an engine 23. The vehicle V may be an HEV or a PHEV equipped with an engine 23 and a motor 22.

[0010] The vehicle control device 100 shown in FIG. 1 includes an ECU (Electronic Control Unit) 10. The ECU 10 is an electronic control unit having a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The storage unit of the ECU 10 includes the ROM and the RAM. The ECU 10 realizes various functions by, for example, executing a program stored in the storage unit by the CPU. The ECU 10 may have multiple electronic control units. Some of the functions of the ECU 10 may be executed by a server capable of communicating with the vehicle V.

[0011] An occupant detection sensor 1, a vehicle speed sensor 2, and an actuator 3 are connected to the ECU 10. The occupant detection sensor 1 may be, for example, a load sensor provided on a seat of the vehicle V. The occupant detection sensor 1 may be an infrared sensor or an in-vehicle camera. The occupant detection sensor 1 may detect the presence of an occupant by detecting an operation by the occupant. The vehicle speed sensor 2 detects the vehicle speed of the vehicle V. The vehicle speed sensor 2 may be a wheel speed sensor that detects the rotational speed of the wheels of the vehicle V. Various other sensors may be connected to the ECU 10.

[0012] The actuator 3 includes a drive mechanism used to control the automatic driving of the vehicle V. The actuator 3 may include a drive actuator, a brake actuator, and a steering actuator. The drive actuator can control the amount of air supplied to the engine 23 and control the driving force of the vehicle V. The drive actuator can control the throttle opening of the engine 23.

[0013] The brake actuator controls the brake system of the vehicle V and can control the braking force of the vehicle V. The steering actuator controls the drive of an assist motor that controls the steering torque of the electric power steering system. The actuator 3 operates based on a control signal output from the ECU 10. The actuator 3 may include other motors and cylinders.

[0014] The vehicle V includes a battery 20 and a PCU (Power Control Unit) 21. The battery 20 and the PCU 21 are connected to the ECU 10. The battery 20 stores power for driving the motor 22. The battery 20 is a secondary battery such as a lithium ion battery or a nickel-metal hydride battery. The PCU 21 is connected to the battery 20 and the motor 22. The PCU 21 connects the battery 20 and the motor 22. The PCU 21 drives the motor 22. The PCU 21 includes a converter and an inverter. The converter boosts the DC current supplied from the battery 20. The inverter converts the DC current into AC current. The motor 22 may be a PM type synchronous generator motor including a rotor having a permanent magnet and a stator having U-phase, V-phase, and W-phase stator coils.

[0015] The inverter includes a plurality of inverter elements. The inverter elements perform switching operations according to a set switching frequency. The switching elements may be, for example, insulated gate bipolar transistors (IGBTs) or silicon carbide-metal oxide semiconductor field effect transistors (SiC-MOSFETs).

[0016] Next, the functional configuration of the ECU 10 will be described. The ECU 10 includes an actuator calculation unit, an actuator drive unit, and a battery calculation unit. The ECU 10 controls unmanned automatic driving and manned automatic driving of the vehicle V. The ECU 10 outputs various signals to control the operations of the actuator 3, the battery 20, the PCU 21, and the motor 22. The ECU 10 may also control the operation of the engine 23.

[0017] The actuator calculation unit can execute drive request calculation processing for the motor 22. The actuator calculation unit may execute drive request calculation processing for the engine 23. The actuator calculation unit can calculate the drive force by the motor 22. The actuator calculation unit may calculate the drive force by the engine 23. The actuator calculation unit can calculate the drive force required for the vehicle V to travel when autonomous driving is performed. The actuator calculation unit may calculate the ratio between the drive force by the motor 22 and the drive force by the engine 23 when autonomous driving is performed.

[0018] The actuator driving unit can generate a driving signal required to drive the motor 22. The actuator calculation unit may generate a driving signal required to drive the engine 23. The actuator calculation unit may generate a driving signal that controls the throttle opening of the engine 23.

[0019] The actuator driver can set the switching frequency of the inverter element of the PCU 21 .

[0020] The battery calculation unit can execute control related to charging and discharging of the battery 20. The battery calculation unit can control the current and voltage of the battery 20.

[0021] The ECU 10 can receive a signal related to the detection result detected by the occupant detection sensor 1. Based on the signal received from the occupant detection sensor 1, the ECU 10 can determine whether the vehicle V is unoccupied or occupied.

[0022] The ECU 10 can receive an input of a signal related to the detection result detected by the vehicle speed sensor 2. The ECU 10 can determine, based on the signal received from the vehicle speed sensor 2, whether or not the speed of the vehicle V is less than a determination threshold value.

[0023] The ECU 10 can determine whether or not autonomous driving is being performed based on various information. The ECU 10 can determine whether or not autonomous driving is being performed based on various information input by the user. The ECU 10 can change various settings according to the driving mode selected by the user.

[0024] The ECU 10 can change the switching frequency of the inverter element of the PCU 21. The ECU 10 can change the switching frequency depending on the vehicle speed of the vehicle V, the state of automatic driving, and the presence or absence of an occupant.

[0025] Next, the process of setting the switching frequency when autonomous driving is performed will be described. FIG. 2 is a flowchart showing the process of setting the switching frequency when autonomous driving is performed. The vehicle V is in an autonomous driving state (S101). In S101, an autonomous driving mode is selected by, for example, a user. The user can select the autonomous driving mode for the vehicle V by transmitting a signal using, for example, a communication terminal. The ECU 10 can control the actuator 3, the battery 20, the PCU 21, the motor 22, and the engine 23 to perform autonomous driving.

[0026] The ECU 10 can drive the engine 23 to execute engine running of the vehicle V. In the engine operation mode, the ECU 10 can drive the engine 23 and the motor 22 to run the vehicle V using the driving force from the engine 23 and the driving force from the motor 22.

[0027] Next, the ECU 10 judges whether or not the vehicle is being driven unmanned. The ECU 10 can judge whether or not the vehicle is being driven unmanned based on the detection result by the occupant detection sensor 1. If the vehicle is being driven unmanned (S102; YES), the ECU 10 performs the process of S104. If the vehicle is being driven manned (S102; NO), the ECU 10 performs the process of S103.

[0028] In S103, the ECU 10 determines whether the vehicle speed of the vehicle V is less than a threshold value. The ECU 10 can determine whether the vehicle speed is less than the threshold value based on the detection result by the vehicle speed sensor 2. If the vehicle speed is less than the threshold value (S103; YES), the ECU 10 performs the process of S105. If the vehicle speed is equal to or greater than the threshold value (S103; NO), the ECU 10 performs the process of S105.

[0029] In S104, the ECU 10 sets a switching frequency with good fuel efficiency. In S104, the ECU 10 can set a switching frequency that is lower than that during manned autonomous driving. The ECU 10 sets the switching frequency so as to improve the fuel efficiency of the vehicle V. In S105, the ECU 10 sets the switching frequency to a high frequency as a high frequency setting. In S105, the ECU 10 sets the switching frequency to a low frequency as a low frequency setting.

[0030] The ECU 10 transmits a signal related to the set switching frequency to the PCU 21. The PCU 21 drives the motor 22 in accordance with the set switching frequency.

[0031] The ECU 10 may determine whether or not the vehicle speed of the vehicle V is less than the determination threshold during unmanned automatic driving. When the vehicle speed is less than the determination threshold during unmanned automatic driving, the ECU 10 can set a frequency with good fuel efficiency (S104).

[0032] A vehicle control device 100 according to one embodiment is a vehicle control device 100 that controls automatic driving of a vehicle V having a motor 22, and includes a PCU 21 having an inverter that drives the motor 22, and an ECU 10 that is a control unit that controls unmanned automatic driving and manned automatic driving. When unmanned automatic driving is being performed, if the vehicle speed of the vehicle V is less than a determination threshold, the ECU 10 sets the switching frequency of the inverter to a lower value compared to when manned automatic driving is being performed.

[0033] During manned autonomous driving, the vehicle control device 100 can control autonomous driving by prioritizing passenger comfort (NV performance) over fuel efficiency. During unmanned autonomous driving, the vehicle control device 100 can control the motor 22 by setting a switching frequency with good fuel efficiency. During unmanned autonomous driving, there is no need to consider passenger comfort, and the motor 22 can be controlled by setting an efficient switching frequency according to the power required for the vehicle V. This can improve the fuel efficiency of the vehicle V during unmanned autonomous driving. During unmanned autonomous driving, the ECU 10 may set a switching frequency with good fuel efficiency regardless of the vehicle speed (S105). The storage unit of the vehicle control device 100 stores values ​​related to the switching frequency.

[0034] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0035] In a vehicle V that is an HEV or a PHEV, the vehicle control device 100 may set the switching frequency of the inverter when generating electricity by the motor generator to be lower than that when manned automatic driving is being performed when unmanned automatic driving is being performed and the vehicle speed is less than a determination threshold. The vehicle control device 100 may change the setting of the switching frequency when traveling using the driving force of the motor generator, and may change the setting of the switching frequency when generating electricity by the motor generator while the engine is operating. [Explanation of symbols]

[0036] V Vehicle 100 Vehicle control device 1 Occupant detection sensor 2 Vehicle speed sensor 3 Actuator 10 ECU 20 Battery 21 PCU 22 Motor 23 Engine

Claims

[Claim 1] A vehicle control device that controls automatic driving of a vehicle having a motor, an inverter that drives the motor; A control unit that controls unmanned automatic driving and manned automatic driving, The control unit is A vehicle control device that, when the unmanned autonomous driving is being performed, if the vehicle speed of the vehicle is less than a judgment threshold, sets a switching frequency of the inverter to a lower frequency compared to when the manned autonomous driving is being performed.

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