JP7403920B2 - Electric vehicle control device - Google Patents

Description

The present invention relates to a control device for an electric vehicle.

2. Description of the Related Art Vehicles such as hybrid vehicles (HV) and electric vehicles (EV) are equipped with a motor as a drive source for driving. The power of the motor is transmitted to a differential gear, and from the differential gear to left and right drive wheels. When the vehicle is decelerating, the regenerative operation of the motor converts the power input to the rotating shaft of the motor into electric power. At this time, the motor acts as a resistance in the drive system, and this resistance acts as a braking force (regenerative braking force) that brakes the vehicle. The electric power generated by the motor is stored in a battery and used for subsequent driving of the motor.

The deceleration of the motor during regenerative operation affects the operability of the vehicle by the user. Therefore, a configuration has been proposed in which a plurality of levels with different strengths of deceleration are set and the user can select the level of deceleration by operating a switch (for example, see Patent Document 1).

JP2014-7844A

However, simply being able to select the level of strength of deceleration does not make it possible to obtain a deceleration that suits the user's detailed preferences or the road conditions on which the user uses the vehicle.

An object of the present invention is to provide a control device for an electric vehicle that can finely set the deceleration of a motor during regenerative operation.

In order to achieve the above object, the control device for an electric vehicle according to the present invention provides power for traveling to the drive system through power running of the motor, and regenerative braking force is applied to the drive system through regenerative operation of the motor. A control device for an electric vehicle that uses a user interface operated by a user, and a control device for reducing vehicle speed within a range up to a preset maximum deceleration for each of a plurality of vehicle speeds based on the operation of the user interface. a deceleration setting means for setting the speed; and a regeneration control means for controlling the regenerative operation of the motor so that the deceleration set by the deceleration setting means according to the vehicle speed is obtained during the regenerative operation of the motor. including.

According to this configuration, the user can arbitrarily set the deceleration due to the regenerative braking force during regenerative operation of the motor for each of a plurality of vehicle speeds by operating the user interface. Since the regenerative operation of the motor is controlled so as to obtain the set deceleration, it is possible to obtain a deceleration that matches the user's detailed preferences and the road conditions on which the user uses the electric vehicle.

The regenerative operation of the motor is not limited to when the service brake (foot brake) of the vehicle is activated, but may be performed even when the accelerator pedal is not depressed and the service brake is not activated. A deceleration due to regenerative operation may be set in a state where the accelerator is off and the service brake is not activated.

With this configuration, the deceleration that occurs when the accelerator is turned off becomes a deceleration that is finely set according to the user's preference, so it is possible to suppress frequent repetition of depressing and depressing the accelerator pedal and the brake pedal. As a result, it is possible to improve the fuel efficiency or electricity consumption of the electric vehicle.

According to the present invention, it is possible to finely set the deceleration rate during regenerative operation of the motor.

1 is a block diagram showing the configuration of an electric vehicle according to an embodiment of the present invention. FIG. 2 is a diagram for explaining setting of deceleration by regenerative braking force of an electric vehicle.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

<Electric vehicle>
FIG. 1 is a block diagram showing the configuration of an electric vehicle 1 according to an embodiment of the present invention.

The electric vehicle 1 is equipped with a series type hybrid system 2. The hybrid system 2 includes an engine (ENG) 11, a generator motor (MG1) 12, a drive motor (MG2) 13, a drive battery 14, and a PCU (Power Control Unit) 15.

Engine 11 is, for example, a gasoline engine or a diesel engine. An engine output gear 22 is provided on the crankshaft 21 of the engine 11 so as to rotate together with the crankshaft 21.

The generator motor 12 is, for example, a permanent magnet synchronous motor. A generator motor gear 24 is provided on the rotating shaft 23 of the generator motor 12 so as to rotate together with the generator motor gear 24 . The generator motor gear 24 meshes with the engine output gear 22. The generator motor 12 is used as a starter motor for cranking the engine 11 when the engine 11 is stopped. After the engine 11 is started, the generator motor 12 functions as a generator that converts the power of the engine 11 into electric power.

The drive motor 13 is, for example, a permanent magnet synchronous motor larger than the generator motor 12. A motor output gear 26 is provided on the rotating shaft 25 of the drive motor 13 so as to rotate together with the rotating shaft 25 .

Motor output gear 26 is coupled to power transmission mechanism 3 mounted on electric vehicle 1. The power transmission mechanism 3 includes a counter shaft 31, a counter gear 32, an output gear 33, and a differential gear 34. The counter shaft 31 is provided parallel to the rotation shaft 25 of the drive motor 13. The counter gear 32 and the output gear 33 are provided on the counter shaft 31 so as to rotate together. The output gear 33 meshes with a ring gear 35 of a differential gear 34. Motor output gear 26 meshes with counter gear 32.

The power of drive motor 13 is transmitted to differential gear 34 via motor output gear 26, counter gear 32, and output gear 33. The power transmitted to the differential gear 34 is then transmitted to the left and right drive wheels 5 of the electric vehicle 1 via the left and right drive shafts 4 . As a result, the left and right drive wheels 5 rotate, and the electric vehicle 1 travels forward or backward.

The driving battery 14 is a battery pack that is a combination of a plurality of secondary batteries (for example, lithium ion batteries). The driving battery 14 outputs, for example, DC power of about 200 to 350 V (volts).

The PCU 15 is a unit for controlling the driving of the generator motor 12 and the drive motor 13, and includes a first inverter (MG1 INV) 41, a second inverter (MG2 INV) 42, and a boost converter (BstCONV) 43.

When the electric vehicle 1 is accelerating, the drive motor 13 is operated in power running, and the drive motor 13 generates power for power running. At this time, the DC power output from the drive battery 14 is boosted as necessary by the boost converter 43, the DC power output from the boost converter 43 is converted into AC power by the second inverter 42, and the AC power is is supplied to the drive motor 13. As a result, the power of the drive battery 14 is consumed.

Further, when the engine 11 is started, the DC power output from the drive battery 14 is boosted by the boost converter 43, the boosted DC power is converted to AC power by the first inverter 41, and the AC power is transferred to the generator motor 12. is supplied to As a result, the generator motor 12 is motored, and the engine 11 is motored by the generator motor 12. This motoring causes the crankshaft of the engine 11 to rotate, and when its rotational speed increases to the rotational speed necessary for starting, the ignition plug of the engine 11 is sparked and the engine 11 is started.

When the generator motor 12 is operated to generate electricity while the engine 11 is operating, the generator motor 12 generates alternating current power. The AC power generated by the generator motor 12 is converted into DC power by the first inverter 41 . Then, the DC power output from the first inverter 41 is converted into AC power by the second inverter 42, and the AC power is supplied to the drive motor 13. Furthermore, when it is not necessary to supply power to the drive motor 13, the DC power output from the first inverter 41 is stepped down by the step-up converter 43, and the stepped down DC power is supplied to the drive battery 14. , the driving battery 14 is charged.

When the electric vehicle 1 is decelerating, the drive motor 13 is operated regeneratively, and the power transmitted from the drive wheels 5 to the drive motor 13 is converted into AC power. At this time, the drive motor 13 acts as a resistance in the travel drive system, and the resistance acts as a braking force (regenerative braking force) that brakes the electric vehicle 1. The AC power generated by the drive motor 13 is converted into DC power by the second inverter 42 . Then, the DC power output from the second inverter 42 is stepped down by the step-up converter 43, and the stepped-down DC power is supplied to the drive battery 14, thereby charging the drive battery 14.

Further, the electric vehicle 1 is equipped with an ECU (Electronic Control Unit) 6 that includes a microcomputer (microcontroller unit) 51 . The microcomputer 51 includes, for example, a CPU, a nonvolatile memory such as a flash memory, and a volatile memory such as a DRAM (Dynamic Random Access Memory). Although only one ECU 6 is shown in FIG. 1, the electric vehicle 1 is equipped with a plurality of ECUs having the same configuration as the ECU 6 in order to control each part. A plurality of ECUs including the ECU 6 are connected to enable bidirectional communication using a CAN (Controller Area Network) communication protocol.

Further, a touch panel 52 is provided in the vehicle interior of the electric vehicle 1, for example, on the instrument panel. The touch panel 52 has, for example, a pressure-sensitive or capacitive transparent film switch attached to a liquid crystal display, and displays various information such as vehicle setting information of the electric vehicle 1 as well as navigation information and music information. It is installed as a multi-information display.

<Deceleration setting>
FIG. 2 is a diagram for explaining the setting of deceleration by regenerative braking force of electric vehicle 1. As shown in FIG.

In the electric vehicle 1, the drive motor 13 is operated regeneratively not only when decelerating due to the operation of the service brake (foot brake) but also when the accelerator pedal is not depressed and the accelerator is off. Regenerative braking force due to the regenerative operation acts on the drive system including the drive wheels 5.

In the electric vehicle 1, by operating the touch panel 52, the deceleration due to the regenerative braking force can be set for each of a plurality of vehicle speeds when the accelerator is off and the service brake is not activated.

Specifically, as shown in FIG. 2, the vehicle speed ranges from 0 km/h to a predetermined maximum vehicle speed (for example, 180 km/h) in multiple vehicle speed ranges, such as a low speed range, a medium speed range, and a high speed range. As shown by the solid line in Figure 2, the maximum deceleration for each vehicle speed range (low speed range, medium speed range, and high speed range) when the accelerator is off and the service brake is not activated is It is set in advance. In the example of the maximum deceleration shown by the solid line in Fig. 2, the maximum deceleration in the low speed range is constant, and the maximum deceleration in the medium speed range increases as the vehicle speed increases from the maximum deceleration in the low speed range. The maximum deceleration in the high speed range is set to smoothly continue with the maximum deceleration in the medium speed range and decrease as the vehicle speed increases.

The user can arbitrarily set the deceleration when the accelerator is off and the service brake is not operating within a range from 0 to the maximum speed for each predetermined vehicle speed (for example, every 1 km/h). . In an initial state, the touch panel 52 displays, for example, a line indicating the deceleration in a state where the accelerator is off and the service brake is not activated, superimposed on the line indicating the maximum deceleration. By partially pressing the line indicating the deceleration with the user's finger and sliding the finger up and down, the deceleration of the vehicle speed corresponding to the portion pressed with the finger can be changed in magnitude. When the deceleration of the vehicle speed corresponding to the part pressed with the finger is changed, the deceleration of the vehicle speed in the vicinity of that vehicle speed is automatically changed so that the line indicating the deceleration changes smoothly. In FIG. 2, two lines indicating the deceleration after changes made by the user are shown, a two-dot chain line and a broken line.

<Effect>
As described above, by operating the touch panel 52, the user can arbitrarily set the deceleration in a state where the accelerator is off and the service brake is not activated for each of a plurality of vehicle speeds. Since the regenerative operation of the drive motor 13 is controlled so as to obtain the set deceleration, it is possible to obtain a deceleration that matches the user's detailed preferences and the road conditions on which the user uses the electric vehicle 1. can.

Further, since the deceleration caused by the accelerator being turned off becomes a deceleration that is carefully set according to the user's preference, it is possible to suppress frequent repetition of depressing/depressing the accelerator pedal and the brake pedal. As a result, it is possible to improve the fuel efficiency or electricity consumption of the electric vehicle 1.

<Modified example>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other forms.

For example, although the touch panel 52 is illustrated as a user interface for setting the deceleration, the user interface is not limited to the touch panel 52. As a user interface, for example, the deceleration set for each vehicle speed may be displayed as a gauge (bar graph) on a display installed in the instrument panel, and the length of the gauge may be adjusted using a dial. good. Furthermore, a terminal such as a smartphone may be used as a user interface.

In the above-described embodiment, the electric vehicle 1 equipped with a series type hybrid system 2 was taken up, but the present invention can be applied to an electric vehicle equipped with a hybrid system of a type other than a series type, such as a series/parallel type. be. In a series/parallel type hybrid system, for example, the engine and motor are connected to a planetary gear mechanism, and the power from the engine can be divided and distributed to the motor and drive wheels. Power can be combined and transmitted to the drive wheels.

Furthermore, the present invention is not limited to electric vehicles equipped with a hybrid system, but can be applied to electric vehicles (EVs) that are not equipped with an engine, as long as they are equipped with a motor as a drive source for driving. You can also do it.

In addition, various design changes can be made to the above-described configuration within the scope of the claims.

1: Vehicle 2: Engine 11: Engine 12: Generator motor (generator)
16: Drive battery (battery)
17: ECU (control device, continuous stop detection means, charging control means, air conditioning control means)
21: Vehicle speed sensor (continuous stop detection means)
22: EPB switch (continuous stop detection means)
23: Air conditioner

Claims (1)

A control device for an electric vehicle, in which power for running is applied to a drive system through power running of a motor, and regenerative braking force is applied to the drive system through regenerative operation of the motor,
a user interface operated by a user;
a deceleration setting means for setting a deceleration within a range having a preset maximum deceleration as an upper limit for each of a plurality of vehicle speeds based on an operation of the user interface;
regeneration control means for controlling the regenerative operation of the motor so that the deceleration set by the deceleration setting means according to the vehicle speed is obtained during the regenerative operation of the motor ;
A control device that causes the user interface to display a deceleration set by the deceleration setting means for each of the plurality of vehicle speeds .

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