WO2023157227A1

WO2023157227A1 - Drive control device for hybrid vehicle

Info

Publication number: WO2023157227A1
Application number: PCT/JP2022/006626
Authority: WO
Inventors: 舜早貸; 洋則安部
Original assignee: 三菱自動車工業株式会社
Priority date: 2022-02-18
Filing date: 2022-02-18
Publication date: 2023-08-24

Abstract

In a vehicle that is capable of a parallel mode in which front wheels are driven by an engine 2 and a front motor 4 and that comprises a motor generator 9 driven to generate power by the engine 2 and a motor clutch 7b in a motive power transmission path between the front motor 4 and the front wheels, a hybrid control unit 20 installed in the vehicle is provided with: a regenerative assistance control part 35 whereby regenerative braking is performed by the motor generator 9 when regenerative braking is requested when the motor clutch 7b is disengaged; and a regenerative power generation control part 36 that reduces the amount of power generated in the motor generator 9 below a reference value to ensure the requested regenerative braking torque when regenerative braking is being executed by the regenerative assistance control part 35 and the total value of the power generation torque consumed by power generation in the motor generator 9 and the requested regenerative braking torque is equal to or greater than the maximum torque of the motor generator 9.

Description

Hybrid vehicle drive control device

The present invention relates to a drive control device for a hybrid vehicle capable of regenerative power generation.

Conventionally, plug-in hybrid vehicles and hybrid vehicles (hereinafter collectively referred to as hybrid vehicles) equipped with an engine and an electric motor as driving sources have been developed with vehicles capable of switching between running modes. Known driving modes include an EV mode driven only by an electric motor, a series mode, and a parallel mode.

For example, the vehicle described in Patent Document 1 is provided with a clutch (engine clutch) in a power transmission path between the engine and the driving wheels. While the series mode in which the vehicle is driven is possible, the parallel mode in which the engine assists the driving force with the motor while the engine is driving the vehicle by connecting the engine clutch is also possible.

Furthermore, in Patent Document 1, a clutch (motor clutch) is provided in the power transmission path between the motor and the driving wheels. By disengaging the motor clutch, it is possible to stop the driving of the motor while the vehicle is driven by the engine. As a result, for example, when the required driving torque drops during high-speed cruising while traveling in parallel mode, the motor clutch can be disengaged and the vehicle can be driven only by the engine while preventing forced driving of the motor. ing. This makes it possible to suppress the power loss due to the control of the motor that has been performed to satisfy the required driving torque.

WO2020/148973/A1

However, in a vehicle equipped with a motor clutch as described above, when regenerative braking is required when the motor clutch is disengaged, the motor clutch must be engaged, making it difficult to rapidly increase the regenerative braking force. is.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and an object of the present invention is to provide a hybrid vehicle in which a large regenerative braking force can be quickly secured when the motor clutch is disengaged in a vehicle equipped with a motor clutch. to provide a drive control device for

In order to achieve the above object, a drive control device for a hybrid vehicle according to the present invention includes an engine that drives driving wheels via a first power transmission path, and a second power transmission path that is different from the first power transmission path. and a second rotating electric machine that is driven by the engine to generate a predetermined amount of electric power, wherein the engine and the first rotating electric machine drive the traveling drive wheels. and a hybrid vehicle capable of regenerative braking by the first rotating electrical machine and the second rotating electrical machine, wherein a clutch provided in the second power transmission path and the running drive wheel a requested regenerative braking torque calculation unit that calculates the requested regenerative braking torque of the clutch, a regenerative assist control unit that performs regenerative braking by the second rotating electric machine when regenerative braking is requested while the clutch is disengaged, and the regenerative When the total value of the power generation torque consumed by power generation in the second rotating electric machine and the requested regenerative braking torque is equal to or greater than a predetermined maximum torque of the second rotating electric machine when the regenerative braking is executed by the assist control unit; and a regenerative power generation control section for reducing the power generation amount of the second rotating electric machine below the predetermined power generation amount.

Accordingly, when regenerative braking is requested by the regenerative assist control unit while the clutch is disengaged and the vehicle is being driven by the engine, the second rotating electrical machine performs regenerative braking to cause the second rotating electrical machine to generate power. It can be used to obtain regenerative braking torque. Therefore, when regenerative braking is requested while the clutch is disengaged, regenerative braking torque can be obtained more quickly than regenerative braking by the first rotating electrical machine with the clutch engaged.

Further, in the regenerative power generation control unit, when regenerative braking is performed by the second rotating electric machine, the total value of the power generation torque consumed by the power generation by the second rotating electric machine and the required regenerative braking torque is determined by the second rotating electric machine. When the torque is equal to or greater than the maximum torque, the amount of power generated by the second rotating electric machine is reduced, so that the regenerative braking torque generated by the second rotating electric machine can be increased within a range in which the consumed torque of the second rotating electric machine does not exceed the maximum torque. .

Preferably, the regenerative power generation control unit sets the regenerative braking torque consumed by the regenerative braking to the requested regenerative braking torque when the power generation amount of the second rotating electric machine is reduced below the predetermined power generation amount. It is preferable to control the power generation amount of the second rotating electric machine.

As a result, in the regenerative power generation control unit, when the amount of power generated by the second rotating electric machine is reduced, the regenerative braking torque by the second rotating electric machine is applied within a range in which the consumption torque of the second rotating electric machine does not exceed the maximum torque. can be torque. Therefore, the required regenerative braking performance can be ensured.

Preferably, the regenerative power generation control unit reduces the output torque of the engine to reduce the power generation amount of the second rotating electric machine below the predetermined power generation amount.

As a result, the amount of power generated by the second rotating electric machine can be easily reduced below the predetermined amount of power generated, and the amount of fuel consumed by the engine can be suppressed.

Preferably, a required driving torque calculation unit for calculating a required driving torque for the traveling drive wheels, and a second electric rotating machine for calculating the required driving torque when the required driving torque exceeds the output torque of the engine while the clutch is disengaged. and a drive assist control unit that applies a drive torque to the driving wheels.

As a result, when the required drive torque increases while the clutch is disengaged and the vehicle is being driven by the engine with the clutch disengaged, the drive assist control unit drives the second rotating electric machine to generate power by driving the second rotating electric machine. It can be used to obtain running drive torque. Therefore, when the required drive torque increases while the clutch is disengaged, the travel drive torque can be increased more quickly than when the clutch is engaged and the drive assist is provided by the first electric rotating machine. It can improve performance.

Preferably, a required driving torque calculating section that calculates a required driving torque of the driving wheels, and a clutch control that disengages the clutch when the required driving torque becomes less than the output torque of the engine in the first traveling mode. and .

As a result, in the first traveling mode in which the traveling drive wheels are driven by the engine and the first rotating electrical machine, the clutch is disengaged when the required drive torque is less than the output torque of the engine. In addition, forced driving of the first rotating electric machine, so-called co-rotation, can be prevented. Therefore, it is possible to suppress power consumption for drive torque control due to co-rotation of the first rotating electric machine.

According to the drive control apparatus for an electric vehicle of the present invention, when the clutch is disengaged and regenerative braking is being performed by the second rotating electric machine, the consumed torque of the second rotating electric machine does not exceed the maximum torque and the torque of the second rotating electric machine is reduced. can be protected. Furthermore, by reducing the amount of power generated by the second rotating electric machine, the regenerative braking torque generated by the second rotating electric machine can be increased, and the regenerative braking performance can be improved.

1 is a schematic configuration diagram of a plug-in hybrid vehicle equipped with a drive control device according to an embodiment of the invention; FIG. 3 is a configuration diagram of a drive/regeneration assist control section in the hybrid control unit according to the embodiment; FIG. FIG. 4 is an explanatory diagram of a torque transmission path in drive/regenerative assist control; It is an example of a time chart showing the transition of the set amount of the generator torque in the regenerative assist control, showing a setting example when the maximum torque of the generator has not been reached. It is an example of a time chart showing changes in the setting of the generator torque, showing a reference example of the setting when the maximum torque of the generator is reached. It is an example of a time chart showing the transition of setting of the generator torque in the present embodiment, and shows a setting example when the maximum torque of the generator is reached.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a plug-in hybrid vehicle (hereinafter referred to as vehicle 1) equipped with a drive control device according to an embodiment of the present invention.

The vehicle 1 of this embodiment is capable of traveling by driving the front wheels 3 with the output of the engine 2, and is provided with an electric front motor 4 (first rotary electric machine) that drives the front wheels 3 (driving wheels). .

The engine 2 can drive the drive shaft 8 of the front wheels 3 via the speed reducer 7, and can drive the motor generator 9 (second rotating electrical machine) via the speed reducer 7 to generate power. there is

The front motor 4 is driven by being supplied with high-voltage electric power from a drive battery 11 (storage battery) mounted on the vehicle 1 and a motor generator 9 via a front inverter 10 , and is driven by a front wheel 3 via a speed reducer 7 . drive the drive shaft 8; In the reduction gear 7, the power transmission path between the engine 2 and the drive shaft 8 and the power transmission path between the front motor 4 and the drive shaft 8 are different paths. The speed reducer 7 incorporates an engine clutch 7 a capable of switching power transmission between the output shaft of the engine 2 and the drive shaft 8 . Further, the speed reducer 7 incorporates a motor clutch 7b capable of switching the transmission of power between the front motor 4 and the drive shaft 8. As shown in FIG.

The power transmission path between the engine 2 and the front wheels 3 corresponds to the first power transmission path of the invention, and the power transmission path between the front motor 4 and the drive shaft 8 corresponds to the second power transmission path of the invention. correspond to

The power generated by the motor generator 9 can charge the drive battery 11 via the front inverter 10 and can also supply power to the front motor 4 .

The drive battery 11 is composed of a secondary battery such as a lithium ion battery, and has a battery module (not shown) configured by collectively configuring a plurality of battery cells. It is provided with a battery monitoring unit 11a for monitoring SOC (hereinafter referred to as SOC) and the like.

The front inverter 10 has a function of controlling the output of the front motor 4 and controlling the amount of power generated by the motor generator 9 based on the control signal from the hybrid control unit 20 .

The vehicle 1 is also equipped with a charger 21 that charges the drive battery 11 with an external power source.

The hybrid control unit 20 is a control device for performing comprehensive control of the vehicle 1, and includes an input/output device, a storage device (ROM, RAM, nonvolatile RAM, etc.), a central processing unit (CPU), and the like. Configured.

The input side of the hybrid control unit 20 is connected with the battery monitoring unit 11a of the drive battery 11, the front inverter 10, the engine control unit 22, the accelerator opening sensor 40 for detecting the amount of accelerator operation, and the like. is input with detection and actuation information from.

On the other hand, the front inverter 10, the speed reducer 7 (

clutches

7a and 7b), and the engine control unit 22 are connected to the output side of the hybrid control unit 20.

Then, the hybrid control unit 20 calculates the vehicle required output required for driving the vehicle 1 and the driving torque for driving based on the various detection amounts and various operation information such as the accelerator opening sensor 40, and the engine A control signal is sent to the control unit 22, the front inverter 10, and the speed reducer 7 to switch the driving mode ((EV mode: electric vehicle mode), series mode, parallel mode), the output of the engine 2 and the front motor 4, and the motor It controls the output (generated power) of the generator 9 .

In the EV mode, the engine 2 is stopped and the electric power supplied from the drive battery 11 drives the front motor 4 to drive the vehicle 1 .

In the series mode, the engine clutch 7a of the speed reducer 7 is disconnected, and the motor generator 9 is operated by the engine 2. The electric power generated by the motor generator 9 and the electric power supplied from the driving battery 11 drive the front motor 4 to cause the vehicle to run. In the series mode, the rotation speed of the engine 2 is set to a predetermined rotation speed, and surplus electric power is supplied to the driving battery 11 to charge the driving battery 11 .

In the parallel mode (first running mode), the engine clutch 7a of the speed reducer 7 is connected, and power is mechanically transmitted from the engine 2 through the speed reducer 7 to drive the front wheels 3. In addition, the front motor 4 is driven by electric power generated by operating the motor generator 9 by the engine 2 and electric power supplied from the drive battery 11 to drive the vehicle.

Note that the motor clutch 7b is in the connected state in the EV mode and the series mode. Also in the parallel mode, the motor clutch 7b is basically in the connected state.

The hybrid control unit 20 sets the running mode to the parallel mode in areas where the engine 2 is efficient, such as high-speed areas. Further, in a region other than the parallel mode, that is, in the middle/low speed region, switching is made between the EV mode and the series mode based on the driving torque of the vehicle 1 and the charging rate SOC of the driving battery 11 .

When the vehicle 1 decelerates with the accelerator off, the front motor 4 is forcibly driven by the rotational force of the front wheels 3 to generate power (regenerative power generation), and regenerative braking is performed to apply braking torque (regenerative braking torque) to the front wheels 3. It has functionality.

FIG. 2 is a configuration diagram of the drive/regeneration assist control section 25 in the hybrid control unit 20. As shown in FIG.

The hybrid control unit 20 of this embodiment further includes a drive/regenerative assist control section 25 that performs drive assist control and regeneration assist control.

The drive/regenerative assist control unit 25 includes a required drive torque calculation unit 31, a required regenerative braking torque calculation unit 32, a motor clutch control unit 33, a drive assist control unit 34, a regenerative assist control unit 35, and a regenerative power generation control unit 36. It is

The required drive torque calculation unit 31 calculates the required drive torque for driving the vehicle 1 to travel.

The requested regenerative braking torque calculator 32 calculates the requested regenerative braking torque of the vehicle 1 .

The motor clutch control unit 33 inputs the driving mode of the vehicle 1 and the engine output torque, and inputs the required drive torque from the required drive torque calculation unit 31 . In the parallel mode, the motor clutch control section 33 disconnects the motor clutch 7b when the required driving torque is satisfied only by the output torque of the engine 2. FIG. Disengaging the motor clutch 7b in this way eliminates the forced rotation (co-rotation) of the front motor 4, which eliminates the need for control to eliminate the induced voltage generated in the front motor 4, thereby suppressing power consumption. can.

The drive assist control unit 34 receives the connection/disconnection instruction signal for the motor clutch 7b from the motor clutch control unit 33, the required drive torque from the required drive torque calculation unit 31, and the engine output torque. When the motor clutch control unit 33 disengages the motor clutch 7b, the drive assist control unit 34 connects the motor clutch 7b to operate the front motor when the required drive torque exceeds the engine output torque due to, for example, an acceleration request due to an accelerator operation. 4 increases the running drive torque. Furthermore, before the motor clutch 7b is connected and the driving torque of the front motor 4 increases, the motor generator 9 is supplied with electric power to drive it, and the driving torque of the motor generator 9 is applied to the drive shaft 8. do.

When the drive assist control is executed, the engine clutch 7a is connected in the parallel mode, and the drive shaft 8 and the motor generator 9 are connected. Therefore, as indicated by the dashed line in FIG. Power is transmitted from the engine 2 while transmitting to the shaft 8 . Therefore, the drive assist can quickly apply the running drive torque.

The regenerative assist control unit 35 receives the connection/disconnection determination signal of the motor clutch 7b from the motor clutch control unit 33 and the requested regenerative braking torque from the requested regenerative braking torque calculation unit. When the motor clutch control unit 33 disengages the motor clutch 7b, the regenerative assist control unit connects the motor clutch 7b and performs regeneration by the front motor 4 when regenerative braking is requested due to a deceleration request due to, for example, an accelerator operation return. braking. Furthermore, before the motor clutch 7b is connected and the regenerative braking torque by the front motor 4 is increased, the motor generator 9 performs regenerative braking to apply the regenerative braking torque to the drive shaft 8, thereby executing regenerative assist control.

When the regeneration assist control is executed, in the parallel mode, the engine clutch 7a is connected and the drive shaft 8 and the motor generator 9 are connected. power is transmitted from the drive shaft 8 to the motor generator 9 . Therefore, regenerative braking torque can be quickly applied by this regenerative assist control.

　Using Figs. 4 to 6, the setting of the generator torque Tg in the regeneration assist control, that is, the setting of the torque input for generating power by the motor generator 9 will be described.

4, 5, and 6 are examples of time charts showing changes in the setting of the generator torque Tg. FIG. 4 shows a case where the generator torque Tg is equal to or less than the maximum torque Tgmax, FIG. 5 shows a reference example where the generator torque Tg reaches the maximum torque Tgmax, and FIG. A setting example when Tgmax is reached is shown.

　As shown in Figures 4 to 6, in the parallel mode, the engine 2 is operated, and the output torque of the engine 2 (engine torque) is used to generate electricity by the motor generator 9. The torque Tga generated by the engine torque is basically controlled to a constant reference value Tg1 as shown in FIGS.

A case where regeneration assist is requested in the motor generator 9 as described above while the motor generator 9 is generating power with the output torque of the engine 2 in the parallel mode will be described below.

As shown in FIG. 4, when the sum of the power generation torque Tga generated by the engine torque in the motor generator 9 and the regenerative braking torque Tgb generated by the regenerative assist is equal to or less than the maximum torque Tgmax generated by the motor generator 9 (Tga+Tgb≦Tgmax), the engine 2 is turned to a predetermined value. , the power generation torque Tga is ensured, and the regenerative braking torque Tgb is obtained by the regenerative assist.

As a reference example, as shown in FIG. 5, when the sum of the power generation torque Tga by the engine torque and the regenerative braking torque Tgb by the regenerative assist exceeds the maximum torque Tgmax by the motor generator 9 (Tga+Tgb>Tgmax), the engine 2 is operated at a predetermined output torque Tep, the amount of electric power generated by the motor generator 9 is ensured. However, in order to protect the motor generator 9, it is necessary to limit the regenerative braking torque generated by the regenerative assist to be lower than the required regenerative braking torque Tgb.

On the other hand, in this embodiment, as shown in FIG. The output torque is reduced below a predetermined output torque Tep. As a result, the power generation torque Tga due to the engine torque is reduced. Along with this, the regenerative braking torque Tgb due to the regenerative assist increases within a range where the sum of the power generation torque Tga due to the engine torque and the regenerative braking torque Tgb due to the regenerative assist does not exceed the maximum torque Tgmax in the motor generator 9 .

As described above, the vehicle 1 of the present embodiment is a plug-in hybrid vehicle having an engine 2 and an electric motor (front motor 4) as driving sources, and the front wheels 3 are driven by the engine 2 and the front motor 4. parallel mode is possible.

Further, the power transmission path between the front motor 4 and the drive shaft 8 of the front wheels 3 is different from the power transmission path between the engine 2 and the drive shaft 8. A motor clutch 7b is provided in the power transmission path between them.

In the parallel mode, when the required drive torque is satisfied only by the output torque of the engine 2, the motor clutch 7b is disengaged to prevent the front motor 4 from rotating together, thereby eliminating the influence of the front motor 4 from rotating together. It is possible to suppress the power consumption due to the control performed for the purpose.

In the parallel mode, when the required drive torque increases while the motor clutch 7b is disengaged and the engine 2 is running, the motor generator 9 is driven to obtain the running drive torque. be able to. Therefore, when the required driving torque increases while the motor clutch 7b is disengaged, it is possible to increase the travel driving torque more quickly than when the motor clutch 7b is connected and the front motor 4 assists the drive. , the driving performance can be improved.

On the other hand, in the parallel mode, when regenerative braking is requested while the motor clutch 7b is disengaged and the vehicle is being driven by the engine 2, the regenerative braking is performed by the motor generator 9. You get torque. Therefore, when regenerative braking is requested while the motor clutch 7b is disengaged, regenerative braking torque can be obtained more quickly than when regenerative braking is performed by the front motor 4 with the motor clutch 7b connected.

Furthermore, in the present embodiment, when the regenerative braking is performed by the motor generator 9 in the regenerative power generation control unit 36, the total value of the power generation torque Tga consumed by the power generation by the motor generator 9 and the requested regenerative braking torque Tgb is is equal to or greater than the maximum torque Tgmax of the motor generator 9, the power generation amount of the motor generator 9 is reduced below the normal power generation amount (predetermined power generation amount) to lower the power generation torque Tga below the reference value Tg1. The regenerative braking torque Tgb by the motor generator 9 can be increased while suppressing the torque Tg from exceeding the maximum torque Tgmax. Thereby, regenerative braking performance can be improved.

In addition, the regenerative power generation control unit 36 sets the regenerative braking torque consumed by regenerative braking to the required value (regenerative braking torque Tgb) when the power generation amount of the motor generator 9 is reduced from the normal power generation amount. As a result, when the power generation amount of the motor generator 9 is reduced by the regenerative power generation control unit 36, the regenerative braking torque of the motor generator 9 is reduced to the regenerative braking torque Tgb within a range in which the torque consumption of the motor generator 9 does not exceed the maximum torque Tgmax. can do. Therefore, the required regenerative braking performance can be ensured.

Further, when the regenerative power generation control unit 36 reduces the amount of power generated by the motor generator 9 from the normal state, the output torque of the engine 2 is reduced. The fuel consumption in 2 can be suppressed.

Although the description of the embodiment is finished above, aspects of the present invention are not limited to the above embodiment. For example, the vehicle 1 of the above embodiment is a front-wheel drive vehicle, but the present invention can also be applied to a four-wheel drive vehicle having rear motors for driving the left and right rear wheels 5, for example. In this case, the required drive torque for the front wheels may be treated as the required drive torque in the above embodiment.

Also, the vehicle 1 of the present embodiment is a plug-in hybrid vehicle (PHEV) capable of external charging or external power supply, but the present invention can also be applied to a hybrid vehicle that does not have a charging function.

1 vehicle (hybrid vehicle)
3 front wheels (driving wheels)
4 Front motor (first rotating electric machine)
9 motor generator (second rotating electric machine)
7b motor clutch (clutch)
31 Required drive torque calculation unit 32 Required regenerative braking torque calculation unit 33 Motor clutch control unit (clutch control unit)
34 drive assist control section 35 regenerative assist control section 36 regenerative power generation control section

Claims

an engine that drives the traveling drive wheels via the first power transmission path;
a first rotary electric machine that drives the traveling drive wheels via a second power transmission path different from the first power transmission path;
a second rotating electric machine that is driven by the engine to generate a predetermined amount of power,
A hybrid vehicle capable of a first traveling mode in which the traveling drive wheels are driven by the engine and the first rotating electric machine and capable of performing regenerative braking by the first rotating electric machine and the second rotating electric machine,
a clutch provided in the second power transmission path;
a requested regenerative braking torque calculation unit that calculates a requested regenerative braking torque for the driving wheels;
a regenerative assist control unit that performs regenerative braking by the second rotating electric machine when regenerative braking is requested while the clutch is disengaged;
When the regenerative braking is executed by the regenerative assist control unit, a total value of power generation torque consumed by power generation in the second rotating electric machine and the requested regenerative braking torque is equal to or greater than a predetermined maximum torque of the second rotating electric machine. a regenerative power generation control unit that reduces the amount of power generated in the second rotating electric machine below the predetermined amount of power generation,
A drive control device for a hybrid vehicle, comprising:
The regenerative power generation control unit adjusts the regenerative braking torque consumed by the regenerative braking to the requested regenerative braking torque when the amount of power generation in the second rotating electric machine is reduced below the predetermined amount of power generation. 2. A drive control device for a hybrid vehicle according to claim 1, wherein the power generation amount of the rotating electric machine is controlled.
3. The hybrid according to claim 1, wherein the regenerative power generation control unit reduces the output torque of the engine to lower the power generation amount of the second rotating electric machine below the predetermined power generation amount. car drive controller.
a required drive torque calculation unit that calculates a required drive torque for the traveling drive wheels;
a drive assist control unit that applies drive torque to the traveling drive wheels by the second rotating electric machine when the required drive torque exceeds the output torque of the engine while the clutch is disengaged. 4. The drive control device for a hybrid vehicle according to any one of claims 1 to 3.
a required drive torque calculation unit that calculates a required drive torque for the traveling drive wheels;
5. The vehicle according to any one of claims 1 to 4, further comprising a clutch control section that disengages the clutch when the required driving torque becomes less than the output torque of the engine in the first running mode. 2. A drive control device for a hybrid vehicle according to claim 1.