JP6977320B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device.

The vehicle drive control device described in Patent Document 1 is known as a technique for correcting an operating point of an engine in a hybrid vehicle including an engine and a motor. In the vehicle drive control device described in Patent Document 1, when the power storage device is charged or discharged while maintaining the driving force, the operating point of the engine is a predetermined target based on the maximum heat efficiency line of the engine. The operating point of the engine is set so that it is within the operating range of the engine.

According to the vehicle drive control device described in Patent Document 1, it is possible to appropriately charge and discharge the power storage device while suppressing deterioration of fuel efficiency of the vehicle.

Japanese Unexamined Patent Publication No. 2013-71467

As described above, in Patent Document 1, the operating point of the engine determined from the required torque of the driver is corrected so as to be within the target engine operating range.

However, in Patent Document 1, when the correction amount of the operating point in the direction of increasing the engine torque with respect to the driver required torque is large, the quietness of the engine is lowered or the driver feels uncomfortable. It made the vehicle behavior unstable.

The present invention has been made by paying attention to the above-mentioned problems, and is capable of preventing the quietness of the engine from being lowered, the driver from feeling uncomfortable, and the vehicle behavior from being unstable. It is intended to provide a control device.

The present invention includes an operation control unit that calculates an engine operating point correction torque that is a correction amount of the engine torque for the driver required torque that is the torque required by the driver for the vehicle, and the operation control unit is the driver required torque. The engine operating point correction torque is limited based on the above.

As described above, according to the above-mentioned invention, it is possible to prevent the quietness of the engine from being lowered, the driver from feeling uncomfortable, and the vehicle behavior from being unstable.

FIG. 1 is a configuration diagram of a vehicle equipped with a vehicle control device according to an embodiment of the present invention. FIG. 2 is a control logic diagram of a correction operation of an operating point of an engine by a vehicle control device according to an embodiment of the present invention. FIG. 3 is a map referred to when determining a correction coefficient in a correction operation of an operating point of an engine by a vehicle control device according to an embodiment of the present invention.

The vehicle control device according to an embodiment of the present invention is a vehicle control device including an engine, which includes an operation control unit that corrects an operating point of the engine, and the operation control unit is a driver's drive request to the vehicle. It is characterized in that the correction amount for correcting the operating point of the engine is limited based on the degree of. Thereby, the vehicle control device according to the embodiment of the present invention can prevent the quietness of the engine from being lowered, the driver from feeling uncomfortable, and the vehicle behavior from being unstable.

Hereinafter, a vehicle control device according to an embodiment of the present invention will be described with reference to the drawings. 1 to 3 are diagrams illustrating a vehicle control device according to an embodiment of the present invention.

As shown in FIG. 1, a vehicle 1 equipped with a vehicle control device according to an embodiment of the present invention includes an engine 2, a transmission 4, and a drive wheel 6.

The engine 2 is composed of, for example, a 4-cycle gasoline engine, and generates power for driving the vehicle. A plurality of cylinders are formed in the engine 2. In this embodiment, the engine 2 is configured to perform a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke for each cylinder.

The transmission 4 has a parallel shaft gear type transmission mechanism, and by switching the gear stage in the transmission mechanism, the power generated by the engine 2 is changed. The transmission 4 includes a clutch 7, which engages and disconnects the driving force transmitted from the engine 2 to the drive wheels 6. The transmission 4 is provided with an actuator (not shown) for operating the opening / closing of the clutch 7 and the switching of the gear stage. The actuator is driven by a drive signal command from the ECU 20.

Further, the transmission 4 includes a ring gear 5, which constitutes a differential device together with a pinion gear, a side gear, and the like (not shown). The drive wheels 6 are connected to the side gears of the differential device via the left and right drive shafts 5a. The power shifted by the transmission 4 is input to the ring gear 5 and then transmitted to the left and right drive wheels 6.

Further, the vehicle 1 includes a motor 3, a speed reducer 8, a battery 11, an inverter 12, and an ECU (Electronic Control Unit) 20.

The motor 3 is a rotary electric machine that functions as an electric machine and a generator, and is connected to the battery 11 via an inverter 12. The motor 3 generates power running torque or power generation torque (regenerative torque) by controlling the inverter 12 by the ECU 20.

The motor 3 is connected to the ring gear 5 via the speed reducer 8 and assists the running of the vehicle 1 by powering with the electric power supplied from the battery 11. Further, the motor 3 generates electricity by being driven by the power transmitted from the ring gear 5. The electric power generated by the motor 3 is charged in the battery 11.

The battery 11 is provided with a battery management module 13 that detects the voltage between terminals of the battery 11, the current input / output to / from the battery 11, and the temperature of the battery 11. The state of charge (SOC) of the battery 11 is detected by the ECU 20 based on the detection signal of the battery management module 13.

As described above, the vehicle 1 in the present embodiment includes the engine 2 and the motor 3 as driving force sources, and is configured as a hybrid vehicle capable of traveling by at least one of the motor torque of the motor 3 and the engine torque of the engine 2. ing. The motor 3 is not limited to the ring gear 5, and may be connected on the power transmission path from the clutch 7 to the drive wheels 6.

The vehicle 1 includes an accelerator opening degree detecting unit 16 and an engine rotation speed detecting unit 17. The accelerator opening degree detecting unit 16 is provided, for example, on an accelerator pedal (not shown), and detects an operation amount of the accelerator pedal as an accelerator opening degree. The engine rotation speed detection unit 17 is provided in the engine 2 and detects the rotation speed of the crankshaft of the engine 2 as the engine rotation speed.

The ECU 20 is composed of a computer unit including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an input port, an output port, and a network module. ing.

The ROM of the ECU 20 stores various constants, various maps, and the like, as well as a program for making the computer unit function as the ECU 20. In the ECU 20, the computer unit functions as the ECU 20 by executing the program stored in the ROM by the CPU. In this embodiment, the ECU 20 controls the operation of the engine 2, the operation of the motor 3, and the operation of the transmission 4.

The ECU 20 calculates the driver-required torque, which is the torque required by the driver for the vehicle 1. Further, the engine torque and the motor torque are determined so as to satisfy the driver required torque by the engine torque and the motor torque. That is, the engine torque and the motor torque are determined so that the sum of the ECU engine torque and the motor torque becomes the driver required torque. The ECU 20 determines the motor torque in consideration of the state of charge of the battery 11.

The ECU 20 includes an SOC detection unit 28, and the SOC detection unit 28 detects the charge state of the battery 11 based on the detection signal of the battery management module 13.

The ECU 20 includes an operation control unit 27, and the operation control unit 27 corrects the operating point of the engine. Here, the operating point is a point consisting of a combination of engine rotation speed and engine torque. The correction of the operating point is to change the engine torque to the increasing side or the decreasing side at a certain engine rotation speed. The operation control unit 27 generates an engine torque larger than the driver required torque for the purpose of operating the engine 2 at an operating point with good thermal efficiency or generating electric power by the motor 3 to charge the battery 11. The operating point of the engine 2 is corrected. That is, the operating point is corrected so that the torque is added to the engine torque by the correction amount, and the motor 3 generates electricity using the surplus engine torque obtained by the correction. In this way, when the operating point of the engine 2 is corrected to the increase side of the engine torque, the battery 11 is charged by driving the engine 2.

Here, if the operating point is corrected by giving priority only to operating the engine 2 at a fuel-efficient operating point, the amount of correction of the operating point in the direction of increasing the engine torque with respect to the driver required torque becomes excessive. May be. If the correction amount of the operating point is excessive, the engine torque may increase and the quietness of the engine 2 may decrease. Further, if the correction amount of the operating point is excessive, the engine noise becomes larger than expected by the driver, which may give the driver a sense of discomfort. Further, if the correction amount of the operating point is excessive, the vehicle behavior may become unstable. Specifically, a chip-in shock, a chip-out shock, a shift shock, or the like accompanied by a change in engine torque occurs, and the vehicle behavior becomes unstable. As described above, if the correction amount of the operating point is excessive, the quietness of the engine 2 may be lowered, the driver may feel uncomfortable, or the vehicle behavior may be unstable. These inconveniences caused by the excessive correction amount of the operating point appear remarkably when the driver required torque is relatively small as compared with the case where the driver required torque is relatively large.

Therefore, in this embodiment, the motion control unit 27 limits the correction amount for correcting the operating point of the engine 2 based on the degree of the driver's drive request to the vehicle 1. The operation control unit 27 limits the correction amount for correcting the operating point of the engine 2 with the upper limit value determined from the driver required torque and the accelerator opening, which are the torques required by the driver for the vehicle 1, as the upper limit. The operation control unit 27 limits the correction amount for correcting the operating point of the engine 2 based on the charge state of the battery 11.

Next, with reference to the control logic diagram shown in FIG. 2, the flow of the correction operation of the engine operating point executed by the operation control unit 27 of the ECU 20 according to the present embodiment will be described.

In FIG. 2, the operation control unit 27 of the ECU 20 includes an engine operating point correction amount calculation unit 27A, and in the engine operating point correction amount calculation unit 27A, referring to a map (not shown), the engine rotation speed and the charging state ( The engine operating point correction amount (referred to as engine operating point correction torque in the figure) is calculated from (denoted as SOC in the figure). The engine operating point correction amount is the correction amount of the engine torque with respect to the driver required torque. That is, the engine operating point correction amount is a correction amount for the operating point corresponding to the driver required torque. The map referred to by the engine operating point correction amount calculation unit 27A differs depending on the gear stage of the transmission 4 and the lever position of the shift lever, and also depending on whether or not the traveling state of the vehicle 1 is in the cruise state. different.

Further, the motion control unit 27 includes a correction coefficient calculation unit 27B. The correction coefficient calculation unit 27B refers to the map shown in FIG. 3 and calculates the correction coefficient from the accelerator opening degree and the charging state (denoted as SOC in the figure). This correction coefficient is a positive value for determining the correction amount of the operating point, and the larger the correction coefficient, the larger the upper limit value for limiting the correction amount. Therefore, the larger the correction coefficient, the larger the correction amount of the operating point. In the map shown in FIG. 3, the vertical axis represents the correction coefficient and the horizontal axis represents the accelerator opening.

In the map of FIG. 3, SOC (A), SOC (B), and SOC (C) represent the charging state, and the relationship is SOC (A) <SOC (B) <SOC (C). In this map, when the accelerator opening is equal, the correction coefficient is set to be smaller as the charging state is larger. Further, when the charging states are SOC (B) and SOC (C), the correction coefficient is set to increase as the accelerator opening degree increases, with the upper limit value of each SOC as the upper limit. Therefore, as the accelerator opening degree increases, the upper limit value for limiting the correction amount increases. That is, as the accelerator opening increases, the correction amount of the operating point is increased with each upper limit value as the upper limit.

Further, when the charging state is the smallest SOC (A), the correction coefficient is set to be constant at the upper limit value regardless of the accelerator opening degree. That is, when the state of charge of the battery 11 is low, charging the battery 11 is given the highest priority, and the correction amount of the operating point is maintained at a certain large upper limit value regardless of the magnitude of the driver required torque. The map shown in FIG. 3 has been experimentally obtained in advance and is stored in the ROM of the ECU 20.

The operation control unit 27 includes a driver-required engine torque correction unit 27C. The driver-required engine torque is corrected by the correction coefficient calculated by the correction coefficient calculation unit 27B. Specifically, the driver required torque correction unit 27C outputs a value obtained by multiplying the driver required engine torque and the correction coefficient. The driver-required engine torque is a positive value when the vehicle 1 is accelerating, and is a negative value when the engine brake is applied and the vehicle 1 is decelerating.

The operation control unit 27 includes a limiter processing unit 27D. The limiter processing unit 27D compares the value input from the driver request engine torque correction unit 27C with 0, and outputs whichever is larger. Therefore, the value output from the limiter processing unit 27D is 0 or a positive value.

The operation control unit 27 includes a limiter processing unit 27E. The limiter processing unit 27E compares the value input from the engine operating point correction amount calculation unit 27A with the value input from the limiter processing unit 27D, and outputs whichever is smaller. Therefore, when the value input from the engine operating point correction amount calculation unit 27A is larger than the value input from the limiter processing unit 27D, the limiter processing unit 27E outputs the value input from the limiter processing unit 27D.

As described above, in the present embodiment, the operation control unit 27 of the ECU 20 limits the correction amount for correcting the operating point of the engine 2 based on the degree of the driver's drive request for the vehicle 1.

As a result, the correction amount of the operating point of the engine 2 is limited to the correction amount based on the degree of the driver's drive request, so that the operating point of the engine 2 is prevented from being excessively corrected in the increasing direction. Therefore, it is possible to prevent the quietness of the engine from being lowered, the driver from feeling uncomfortable, and the vehicle behavior from being unstable.

Further, in the present embodiment, the motion control unit 27 limits the correction amount with the upper limit value determined from the driver required torque and the accelerator opening, which are the torques required by the driver for the vehicle 1, as the upper limit.

As a result, the correction amount is limited to the upper limit value, so that the operating point of the engine 2 is prevented from being excessively corrected in the increasing direction. Therefore, it is possible to prevent the quietness of the engine from being lowered, the driver from feeling uncomfortable, and the vehicle behavior from being unstable.

Further, in the present embodiment, the vehicle 1 includes a battery 11 that is charged by driving the engine 2. Then, the operation control unit 27 limits the correction amount based on the charge state of the battery 11.

As a result, the correction amount for correcting the operating point of the engine 2 can be limited so that the battery 11 is not overcharged, so that the battery 11 can be protected.

Although embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art that modifications may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

1 Vehicle 2 Engine 20 ECU (Vehicle control unit)
27 Motion control unit

Claims (4)

It is equipped with an operation control unit that calculates the engine operating point correction torque, which is the correction amount of the engine torque for the driver required torque, which is the torque required by the driver for the vehicle.
The motion control unit is a vehicle control device that limits the engine operating point correction torque based on the driver required torque. The operation control unit, the upper limit value determined from said driver request torque and accelerator opening as an upper limit, a control apparatus for a vehicle according to claim 1, characterized in that to limit the engine operating point correction torque. The vehicle control device according to claim 2, wherein the upper limit value increases as the accelerator opening degree increases. The vehicle comprises a battery that is charged by driving an engine.
The vehicle control device according to claim 1 or 3, wherein the operation control unit limits the engine operating point correction torque based on the state of charge of the battery.

Images