JP7255174B2 - Motor torque controller for hybrid vehicle - Google Patents

Description

The present invention relates to a motor torque control device for a hybrid vehicle.

In Patent Document 1, a motor/generator is disposed between an engine and a clutch, and an automatic clutch is interposed between the motor/generator and the engine to automatically perform engagement and release operations. A hybrid vehicle is disclosed that is configured with a

Japanese Patent No. 5811262

However, in the above-described conventional hybrid vehicle, the automatic clutch disengagement is included in the start condition regardless of the driving mode, so power transmission between the engine and the motor/generator during the HEV driving mode. is blocked. Therefore, when the vehicle is started in the HEV mode, the motor/generator cannot generate electricity by driving the engine. put away.

In order to suppress this decrease in remaining battery capacity, when the vehicle is started in the HEV driving mode, it is possible to set the engagement of the automatic clutch as a starting condition so that the power can be generated by the motor by transmitting power from the engine. It is conceivable, but if the starting condition is that the automatic clutch is engaged only in the HEV driving mode, the HEV driving mode that requires half-clutch operation when starting and the EV driving mode that does not require half-clutch operation when starting, Since the driving operations are in different situations, the driver may confuse which driving mode the vehicle operation should be performed for each driving mode.

The present invention has been made in view of the circumstances as described above, and prevents the driver from confusing the driving operation due to the different starting operation for each driving mode, and suppresses the decrease in the remaining battery capacity in the HEV driving mode. An object of the present invention is to provide a motor torque control device for a hybrid vehicle.

In order to achieve the above objects, the present invention provides a motor torque control device for a hybrid vehicle in which an engine and a motor are connected via an automatic clutch, and the motor and a transmission are connected via a manual clutch, As driving modes of the hybrid vehicle, an EV mode in which the automatic clutch is released and the vehicle is driven by the power of the motor, and an HEV mode in which the automatic clutch is engaged and the vehicle is driven by the power of the engine or the engine and the motor. and a control unit that switches between the EV mode and the HEV mode according to the degree of accelerator opening and the vehicle speed, and the control unit controls the rotation speed of the motor when starting the vehicle. When the rotation speed is in a low rotation region corresponding to an idle rotation speed or less, the torque of the motor is controlled so that the rotation speed of the motor becomes a rotation speed corresponding to the idle rotation speed of the engine, and the torque in the low rotation region is controlled. It has the structure which reduces the torque of the said motor so that starting may become difficult.

According to the present invention, motor torque control for a hybrid vehicle can prevent a driver from confusing driving operations due to different starting operations for each driving mode, and can suppress a decrease in the remaining battery level during the HEV driving mode. Equipment can be provided.

FIG. 1 is a schematic configuration diagram of a hybrid vehicle according to one embodiment of the present invention. FIG. 2 is a flow chart showing the flow of torque control processing executed by the ECU installed in the hybrid vehicle according to one embodiment of the present invention. FIG. 3 is a start transition mode torque map referred to by an ECU installed in a hybrid vehicle according to one embodiment of the present invention. FIG. 4 is an EV mode torque map referred to by an ECU mounted on a hybrid vehicle according to one embodiment of the present invention.

A motor torque control apparatus for a hybrid vehicle according to an embodiment of the present invention provides motor torque control for a hybrid vehicle in which an engine and a motor are connected via an automatic clutch and a motor and a transmission are connected via a manual clutch. A control device for a hybrid vehicle, which has an EV mode in which the clutch is automatically released and the hybrid vehicle travels by the power of the motor, and an HEV mode in which the clutch is automatically engaged and the vehicle travels by the power of the engine or the engine and the motor. and a control unit that switches between the EV mode and the HEV mode according to the accelerator opening and the vehicle speed. When the vehicle is in the low rotation region, the torque of the motor is reduced so that starting in the low rotation region becomes difficult. As a result, the motor torque control device for a hybrid vehicle according to the embodiment of the present invention prevents the driver from confusing the driving operation due to the different starting operation for each driving mode, and reduces the remaining battery power in the HEV driving mode. It is possible to suppress the amount decrease.

A hybrid vehicle equipped with a motor torque control device according to an embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a hybrid vehicle 1 according to the present embodiment includes an engine 2, a motor generator 3 as a motor, a manual transmission 4 as a transmission, a differential 5, drive wheels 6, and a controller as and an ECU (Electric Control Unit) 10 .

A plurality of cylinders are formed in the engine 2 . In this embodiment, the engine 2 is constructed so that each cylinder performs a series of four strokes consisting of an intake stroke, a compression stroke, an expansion stroke and an exhaust stroke.

The motor generator 3 has a function as an electric motor driven by electric power supplied from the battery 31 via the inverter 30 and a function as a generator that generates power by reverse driving force input from the manual transmission 4 .

Under the control of the ECU 10, the inverter 30 converts the DC power supplied from the battery 31 into three-phase AC power and supplies it to the motor generator 3, or converts the three-phase AC power generated by the motor generator 3 into DC power. to charge the battery 31. The battery 31 is composed of a secondary battery such as a lithium ion battery, for example.

The manual transmission 4 is configured by a manual transmission that outputs the rotation output from the engine 2 or the motor generator 3 or both at a gear ratio corresponding to one of a plurality of gear stages. A manual transmission 4 is connected to left and right drive wheels 6 via a differential 5 .

Gear stages that can be established by the manual transmission 4 include, for example, gear stages for running from 1st to 4th gears and reverse gears. The number of speed stages for running varies depending on the specifications of the hybrid vehicle 1, and is not limited to the first to fourth speed stages described above.

The gear stage of the manual transmission 4 is switched according to the operating position of a shift lever 40 operated by the driver. The operating position of the shift lever 40 is detected by a shift position sensor 41 . The shift position sensor 41 is connected to the ECU 10 and transmits detection results to the ECU 10 .

A neutral switch 42 is provided in the manual transmission 4 . Neutral switch 42 is connected to ECU 10 . The neutral switch 42 detects that the manual transmission 4 is in a state in which none of the gear stages are established, that is, in a neutral state, and is turned on when the manual transmission 4 is in the neutral state.

An automatic clutch 7 is provided in a power transmission path between the engine 2 and the motor generator 3 . As the automatic clutch 7, for example, a friction clutch can be used. The engine 2 and motor generator 3 are connected via an automatic clutch 7 .

The automatic clutch 7 is operated by a clutch actuator 70 to switch between an engaged state in which power is transmitted between the engine 2 and the motor generator 3 and a released state in which power is not transmitted. The clutch actuator 70 is connected to the ECU 10 and controlled by the ECU 10 .

A manual clutch 8 is provided in a power transmission path between the motor generator 3 and the manual transmission 4 . Motor generator 3 and manual transmission 4 are connected via manual clutch 8 .

The manual clutch 8 is a mechanical clutch that operates in conjunction with the depression amount of a clutch pedal 80 operated by the driver. As the manual clutch 8, for example, a friction clutch can be used.

The depression amount of the clutch pedal 80 is detected by a clutch pedal sensor 81 . The clutch pedal sensor 81 is connected to the ECU 10 and transmits to the ECU 10 a signal corresponding to the depression amount of the clutch pedal 80 .

The hybrid vehicle 1 has an accelerator pedal 90 operated by the driver. The depression amount of the accelerator pedal 90 is detected by an accelerator opening sensor 91 . The accelerator opening sensor 91 is connected to the ECU 10 , detects the depression amount of the accelerator pedal 90 as an accelerator opening, and transmits a signal corresponding to the accelerator opening to the ECU 10 .

The ECU 10 is a computer having a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory for storing backup data, an input port, and an output port. made up of units.

The ROM of the computer unit stores a program for causing the computer unit to function as the ECU 10 along with various constants, various maps, and the like. That is, the computer unit functions as the ECU 10 in this embodiment by the CPU executing a program stored in the ROM using the RAM as a work area.

A vehicle speed sensor 11 is connected to the ECU 10 in addition to the sensors described above. The vehicle speed sensor 11 detects the vehicle speed of the hybrid vehicle 1 and transmits the detection result to the ECU 10 .

The ECU 10 switches the running modes of the hybrid vehicle 1 . An EV mode and an HEV mode are set as the running modes in this embodiment.

The EV mode is a driving mode in which the automatic clutch 7 is released and the hybrid vehicle 1 is driven by the power of the motor generator 3 . The HEV mode is a driving mode in which the automatic clutch 7 is engaged and the hybrid vehicle 1 is driven by the power of the engine 2 or the engine 2 and the motor generator 3 .

The ECU 10 switches between the EV mode and the HEV mode according to the accelerator opening detected by the accelerator opening sensor 91 and the vehicle speed detected by the vehicle speed sensor 11 .

In the EV mode, when the manual clutch 8 is engaged and the manual transmission 4 is in neutral for a predetermined time or longer, the ECU 10 determines that the driver does not intend to start the vehicle, and shifts to the stop mode. , the output of the motor generator 3 is reduced. The ECU 10 reduces the output of the motor generator 3 by reducing the torque of the motor generator 3 (hereinafter referred to as "MG torque"). The ECU 10 may reduce the rotation speed of the motor generator 3 (hereinafter referred to as "MG rotation speed") instead of the MG torque.

When starting the hybrid vehicle 1 in the EV mode, when the MG rotation speed is in a low rotation region corresponding to the idle rotation speed of the engine 2 or less, the ECU 10 controls the motor generator 3 so that starting in the low rotation region becomes difficult. is designed to reduce the torque of the

When starting in the EV mode, the ECU 10 increases the rotation speed of the motor generator 3 to the idle rotation speed of the engine in accordance with the start transition mode torque map shown in FIG. First, the torque of the motor generator 3 is decreased after the torque of the motor generator 3 is increased. The start transition mode torque map shown in FIG. 3 is a map in which the MG torque is associated with the MG rotation speed, and is experimentally determined in advance and stored in the ROM of the ECU 10 . In the start transition mode torque map shown in FIG. 3 , the MG torque is set to positive torque until the MG rotation speed increases to MG_idle rotation speed corresponding to the idle rotation speed of the engine 2 .

The ECU 10 increases the MG torque corresponding to the inertia torque of the engine according to the change rate of the MG rotation speed when the manual clutch 8 shifts from the disengaged state to the engaged state in the EV mode. Here, when the manual clutch 8 changes from the released state to the connected state in the EV mode, for example, when the hybrid vehicle 1 is in the stop mode, the driver depresses the clutch pedal 80 to start the hybrid vehicle 1. An operation in which the clutch pedal 80 is released from the depressed state after the clutch pedal 80 has been depressed, and an operation in which the driver depresses the clutch pedal 80 to change gears while the vehicle is running and the clutch pedal 80 is released from the depressed state after the gear is changed. be.

In this embodiment, after the manual clutch 8 is released in the stop mode, the MG torque is increased as shown in FIG. Therefore, by reducing the MG torque, the MG torque is controlled so that the MG rotation speed becomes MG_idle rotation speed corresponding to the idle rotation speed of the engine 2 . After the manual clutch 8 is released in the vehicle stop mode, the period until the MG rotation speed reaches the idling rotation speed of the engine 2 is defined as a start transition mode. The start transition mode corresponds to when the MG rotation speed is in the low rotation region described above.

In the EV mode, the ECU 10 controls the torque of the motor generator 3 according to the EV mode torque map shown in FIG. Specifically, when the manual clutch 8 is in the disengaged state or the manual transmission 4 is in the neutral state, the rotational speed of the MG is controlled to correspond to the MG_idle rotational speed.

When the manual clutch 8 shifts from the disengaged state to the half-engaged state, the rotation speed of the MG decreases from the MG_idle rotation speed. It increases the torque of MG.

The EV mode torque map shown in FIG. 4 is a map in which the MG torque is associated with the MG rotational speed, and is experimentally determined in advance and stored in the ROM of the ECU 10 .

Next, referring to FIG. 2, torque control processing executed by the ECU 10 according to this embodiment will be described. The torque control shown in FIG. 2 is repeatedly executed at predetermined time intervals while the hybrid vehicle 1 is running.

As shown in FIG. 2, the ECU 10 acquires various sensor information of the hybrid vehicle 1 (step S1). The ECU 10 determines which of the EV mode and the HEV mode should be selected as the driving mode of the hybrid vehicle 1 based on the accelerator opening, the vehicle speed, and the like (step S2).

The ECU 10 determines whether or not the EV mode has been selected as the running mode of the hybrid vehicle 1 (step S3). When the ECU 10 determines that the EV mode is not selected as the running mode, that is, the HEV mode is selected, the ECU 10 controls the automatic clutch 7 to be engaged (step S4). As a result, the power of the engine 2 can be transmitted to the driving wheels 6 .

Next, the ECU 10 performs HEV mode MG torque control and engine torque control (step S5), and terminates the torque control process. Specifically, in step S5, the ECU 10 controls the engine torque and the MG torque so that the driving force corresponding to the accelerator opening is satisfied and the state of charge of the battery 31 is brought to an appropriate state.

For example, when the state of charge of the battery 31 is lower than the target value, the MG torque command value is determined so that the motor generator 3 generates power, and the torque required to drive the hybrid vehicle 1, that is, the driving force corresponding to the accelerator opening degree is determined. A value obtained by adding the torque required for power generation by the motor generator 3 to the torque required to satisfy the above is set as the engine torque command value. Further, when the driving force corresponding to the accelerator opening cannot be satisfied only by the engine torque, the insufficient torque is set as the MG torque command value.

When the ECU 10 determines in step S3 that the EV mode is selected as the running mode, it controls the automatic clutch 7 to be released (step S6). As a result, the power transmission path between the engine 2 and the motor generator 3 is cut off.

Next, the ECU 10 determines whether or not the vehicle is in stop mode (step S7). The ECU 10 determines that the vehicle is in the stop mode when the manual clutch 8 is in the engaged state and the manual transmission 4 is in the neutral state for a predetermined time or longer.

If the ECU 10 determines in step S7 that the vehicle is in the stop mode, the ECU 10 can determine that the driver does not intend to travel, so it sets the MG torque command value to 0 and terminates the torque control process. As a result, in the vehicle stop mode, the MG torque can be reduced and finally set to 0, and as a result, the output of the motor generator 3 is suppressed. As a result, the rotation of the motor generator 3 is stopped and power consumption is suppressed.

When the ECU 10 determines in step S7 that the vehicle is not in the stop mode, it determines whether or not the vehicle is in the start transition mode (step S9). The ECU 10 determines that the vehicle is in the start transition mode when the MG rotation speed reaches the MG_idle rotation speed after the manual clutch 8 is released in the vehicle stop mode.

In step S9, when the ECU 10 determines that the start transition mode is set, the ECU 10 refers to the torque map for the start transition mode shown in FIG. (Step S10). In step S10, the ECU 10 controls the MG torque so as to increase the MG rotation speed to the MG_idle rotation speed. After the process of step S10, the ECU 10 ends the torque control process.

In step S9, when the ECU 10 determines that the vehicle is not in the start transition mode, the ECU 10 determines that the vehicle is running in the EV mode, refers to the EV mode torque map shown in FIG. It is calculated as an MG torque command value (step S11). "While running in EV mode" includes when the vehicle is started in a non-start transition mode, that is, when the MG rotation speed has reached the MG_idle rotation speed.

In the EV mode torque map shown in FIG. 4, the MG torque command value is set to 0 or a negative value regardless of the accelerator opening in the region of the MG rotation speed lower than the MG_idle rotation speed.

In this embodiment, by using the above-described EV mode torque map not only when starting after reaching the MG_idle rotational speed in the EV mode, but also during running in the EV mode, for example, an operation error of the shift lever 40 can be prevented. Therefore, when an unsuitable gear stage on the high-speed gear side is selected, the driving force is greatly reduced.

Next, the ECU 10 calculates an inertia correction torque corresponding to the rate of change of the MG rotation speed, and adds the calculated inertia correction torque to the MG torque command value calculated in step S11 to obtain a final MG torque command value. (Step S12). The ECU 10 controls the motor generator 3 based on the final MG torque command value calculated in step S12.

The inertia correction torque is a positive torque that increases the MG rotation speed when the change rate of the MG rotation speed is negative, that is, when the MG rotation speed is decreasing. It is obtained by multiplying the moment by the angular acceleration of the motor generator 3 . After the process of step S12, the ECU 10 ends the torque control process.

As described above, the motor torque control device for a hybrid vehicle according to the present embodiment sets the MG torque to 0 when the manual clutch 8 is engaged and the manual transmission 4 is in the neutral state in the EV mode. configured to control.

As a result, the motor torque control apparatus for a hybrid vehicle according to the present embodiment suppresses the output of the motor generator 3 when the manual clutch 8 is engaged and the manual transmission 4 is in the neutral state in the EV mode. and the power consumption of the battery 31 can be suppressed. As a result, the motor torque control device for a hybrid vehicle according to the present embodiment can suppress a decrease in the remaining amount of the battery 31 during the EV mode. Therefore, even in a situation where the vehicle repeatedly starts and stops for a long period of time, such as in a traffic jam, the output of the motor generator 3 can be suppressed, so that the decrease in the remaining amount of the battery 31 can be suppressed.

In addition, when the hybrid vehicle 1 is started in the EV mode, the motor torque control device for a hybrid vehicle according to the present embodiment, when the MG rotation speed is in a low rotation region corresponding to the MG_idle rotation speed or less, is configured to reduce the MG torque so that the start of the vehicle becomes difficult.

As a result, the motor torque control device for a hybrid vehicle according to the present embodiment can prevent starting in the EV mode unless the clutch is operated in the same manner as in the case where the vehicle is started by the power of the engine 2. can. Therefore, even when the vehicle is started in the EV mode, the same clutch operation as when the vehicle is started by the power of the engine 2 is required. .

Further, in the EV mode, the motor torque control device for a hybrid vehicle according to the present embodiment adds inertia correction torque corresponding to the change rate of the MG rotation speed to the MG torque command value after the manual clutch 8 is released. By doing so, the MG torque is increased in accordance with the change rate of the MG rotational speed.

Here, the moment of inertia of the motor generator 3 is smaller than the moment of inertia of the engine 2 including the flywheel. Further, when the hybrid vehicle 1 is started by the power of the engine 2, the moment of inertia on the upstream side of the power transmission path of the manual clutch 8 is the sum of the moment of inertia of the engine 2 including the flywheel and the moment of inertia of the motor generator 3. It will be

Therefore, when the hybrid vehicle 1 is started by the power of the motor generator 3 , the moment of inertia is smaller than when the hybrid vehicle 1 is started by the power of the engine 2 . Therefore, when the manual clutch 8 is half-clutch operated, the MG rotation speed tends to decrease, which may make it difficult to start the vehicle.

In this embodiment, when the driver depresses the clutch pedal 80 to start the vehicle in the stop mode, the inertia correction torque corresponding to the change rate of the MG rotation speed is added to the MG torque command value to Since the MG torque is increased in accordance with the rate of change of the rotation speed, it is possible to alleviate the drop in the MG rotation speed when the manual clutch 8 is half-clutched. Therefore, even when the vehicle is started in the EV mode, the vehicle can be started with a clutch operation similar to when the vehicle is started by the power of the engine 2 .

In this embodiment, when the manual clutch 8 is released in the EV mode and the vehicle stop mode, the vehicle is shifted to the start transition mode. there is In this case, the MG rotational speed needs to be equal to or higher than the MG_idle rotational speed at the time when the driver actually starts the start operation (for example, at the timing when he starts depressing the accelerator pedal 90).

Therefore, in the EV mode and the vehicle stop mode, when the manual clutch 8 is not operated, the rotation of the motor generator 3 is controlled to stop. You may control so that it may become more than rotation speed. In this case, it is possible to prepare for the driver's starting operation while suppressing power consumption.

Further, in the present embodiment, when the MG rotation speed falls below the MG_idle rotation speed due to rough clutch operation or an erroneous operation of the shift lever 40 during the EV mode except the start transition mode, it is treated as a pseudo engine stall. The hybrid vehicle 1 may be configured so that the hybrid vehicle 1 cannot be started unless the starting operation is performed again, or may be configured to shift to the start transition mode when the manual clutch 8 is released.

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

1 hybrid vehicle 2 engine 3 motor generator (motor)
4 Manual transmission
7 automatic clutch 8 manual clutch 10 ECU (control unit)
REFERENCE SIGNS LIST 11 vehicle speed sensor 40 shift lever 41 shift position sensor 42 neutral switch 80 clutch pedal 81 clutch pedal sensor 90 accelerator pedal 91 accelerator opening sensor

Claims (5)

A motor torque control device for a hybrid vehicle in which an engine and a motor are connected via an automatic clutch, and the motor and a transmission are connected via a manual clutch,
As driving modes of the hybrid vehicle, an EV mode in which the automatic clutch is released and the vehicle is driven by the power of the motor, and an HEV mode in which the automatic clutch is engaged and the vehicle is driven by the power of the engine or the engine and the motor. and
A control unit that switches between the EV mode and the HEV mode according to the accelerator opening and the vehicle speed,
When starting the vehicle, the control unit adjusts the rotation speed of the motor to the idle rotation speed of the engine when the rotation speed of the motor is in a low rotation region corresponding to the idle rotation speed of the engine or less. A motor torque control device for a hybrid vehicle , wherein the torque of the motor is controlled so as to achieve a rotation speed, and the torque of the motor is reduced so that starting in the low rotation region becomes difficult. When starting the vehicle, the control unit adjusts the rotation speed of the motor to the idle rotation speed of the engine when the rotation speed of the motor is in a low rotation region corresponding to the idle rotation speed of the engine or less. After increasing the torque of the motor in order to increase the rotational speed, the torque of the motor is decreased as the rotational speed of the motor approaches a rotational speed corresponding to the idle rotational speed of the engine. A motor torque control device for a hybrid vehicle according to claim 1. 3. The control unit according to claim 1, wherein the control unit increases the torque of the motor according to the rotational angular acceleration of the motor when the manual clutch is shifted from the disengaged state to the engaged state. A motor torque control device for a hybrid vehicle as described. 4. The control unit reduces the output of the motor when the manual clutch is in an engaged state and the transmission is in a neutral state. 2. A motor torque control device for a hybrid vehicle according to claim 1. 5. The controller according to any one of claims 1 to 4 , wherein the control unit stops the output of the motor when the manual clutch is in the engaged state and the transmission is in the neutral state. A motor torque control device for a hybrid vehicle according to claim 1.

Images