CN108773294B - Single-motor four-wheel drive electric automobile starting and running control method - Google Patents

Abstract

The invention discloses a single-motor four-wheel drive electric automobile starting and running control method, wherein an electric automobile comprises a whole automobile controller and a driving motor, one end of the driving motor is connected with a front driving speed reducer through a front clutch, the other end of the driving motor is connected with a rear driving speed reducer through a rear clutch, the front driving speed reducer is connected with a front wheel, and the rear driving speed reducer is connected with a rear wheel; the method comprises the following steps: the vehicle control unit controls the starting of the electric vehicle according to the actual load condition of the electric vehicle; after starting, the vehicle control unit controls the running mode of the electric vehicle according to the actual load condition, wherein the running mode comprises a front wheel and rear wheel simultaneous driving mode, a front wheel driving mode and a rear wheel driving mode. The invention can effectively realize the optimized control of the automobile power; the weight and the cost of the whole automobile are greatly reduced, enough power can be better transmitted to the road surface, and the acceleration and off-road capability of the automobile are enhanced.

Description

Single-motor four-wheel drive electric vehicle starting and driving control method

technical field

The invention relates to the technical field of electric vehicles, in particular to a starting and running control method of an electric vehicle driven by a single motor and four wheels.

Background technique

An electric vehicle is a vehicle powered by an on-board power supply and driven by a motor to drive the wheels. Electric vehicle is an environmentally friendly vehicle. It uses electricity instead of oil as its main power source. It has the characteristics of low carbon emission and environmental friendliness. It has the traditional internal combustion engine in terms of alleviating the energy crisis, making full use of renewable energy, and reducing greenhouse gas emissions. The incomparable advantage of the car. However, the existing electric vehicles usually adopt a single-axle two-wheel drive mode. The main power of the vehicle is mainly concentrated on the front or rear wheels as the driving wheels, which is easy to cause uneven force on each wheel, and the acceleration ability and off-road ability of the vehicle. It is weak, and the vehicle handling safety is low. In addition, the existing four-wheel drive electric vehicles usually use a dual-motor drive system, which has high vehicle weight and cost, and cannot flexibly realize two-wheel drive during starting and driving. And the conversion of four-wheel drive mode, it is easy to cause waste of energy.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a single-motor four-wheel drive electric vehicle starting and driving control method, which can flexibly control the starting and driving mode switching of the vehicle according to the vehicle load, and realize the optimal control of the vehicle power; It is driven by a single motor and can automatically switch between four-wheel drive mode and other modes, which greatly reduces the weight and cost of the whole vehicle, and can transmit enough power to the road, enhance the acceleration and off-road capabilities of the car, and improve the handling safety of the car.

In order to solve the above-mentioned technical problems, the technical solutions provided by the present invention are as follows:

A single-motor four-wheel drive electric vehicle starting and driving control method, the electric vehicle comprises a vehicle controller and a drive motor, one end of the drive motor is connected with a front drive reducer through a front clutch, and the other end is connected through a front clutch. The rear clutch is connected with the rear drive reducer, the front drive reducer is connected with the front wheel, the rear drive reducer is connected with the rear wheel, and the front wheel and the rear wheel are both provided with wheel side clutches; the The method includes the following steps:

1) The vehicle controller controls the start of the electric vehicle according to the actual load of the electric vehicle;

2) After the electric vehicle starts, the vehicle controller controls the driving mode of the electric vehicle according to the actual load of the electric vehicle, and the driving modes include the simultaneous driving mode of the front and rear wheels, the front-wheel driving mode and the rear-wheel driving mode.

In one embodiment, the step 1) is specifically:

When the vehicle controller monitors the power allowable output signal and the driving gear signal, it determines whether the actual load of the electric vehicle is less than the load setting value. If so, the vehicle controller controls the rear wheel to engage its wheel clutch, and Control the drive motor to engage with the rear clutch, and then control the drive motor to run after monitoring that the accelerator pedal signal reaches the first set signal value. The drive motor directly drives the rear wheels through the rear drive reducer to drive the electric vehicle to start and drive at low speed. ; If not, the vehicle controller controls the rear wheel to engage with its wheel clutch, the drive motor to engage the rear clutch, the front wheel to engage its wheel clutch, and the drive motor to engage the front clutch, and then After monitoring that the accelerator pedal signal reaches the second set signal value, the drive motor is controlled to run. The drive motor drives the rear wheel to run through the rear drive reducer, and simultaneously drives the front wheel through the front drive reducer to drive the electric vehicle to start.

In one embodiment, the step 1) is specifically: the load setting value is 35% of the rated load of the electric vehicle.

In one embodiment, the value of the first setting signal is 0-3.5V; the value of the second setting signal is 3.5-5V.

In one embodiment, the step 2) is specifically:

When the vehicle controller detects that the actual load of the electric vehicle is less than 35% of the rated load, and the accelerator pedal signal is less than 2.5V, the electric vehicle enters the front-wheel drive mode;

When the vehicle controller detects that 35% of the rated load of the electric vehicle ≤ actual load < 75% of the rated load, and monitors 2.5V ≤ accelerator pedal signal < 3.5V, the electric vehicle enters the rear-wheel drive mode;

When the vehicle controller detects that 75% of the rated load of the electric vehicle≤actual load≤rated load, and monitors 3.5V≤accelerator pedal signal≤5V, the electric vehicle enters the simultaneous driving mode of the front and rear wheels.

In one embodiment, the step 2) is specifically:

When the vehicle controller detects that the actual load of the electric vehicle is less than 35% of the rated load, and the electric vehicle travels to the set speed, the electric vehicle enters the front-wheel drive mode;

When the vehicle controller detects that 35% of the rated load of the electric vehicle ≤ actual load < 75% of the rated load, and the electric vehicle travels to the set speed, the electric vehicle enters the rear-wheel drive mode;

When the vehicle controller detects that 75% of the rated load of the electric vehicle ≤ actual load ≤ rated load, and the electric vehicle travels to the set speed, the electric vehicle enters the simultaneous driving mode of the front and rear wheels.

In one embodiment, the front-wheel drive mode adopts the following control method: the vehicle controller controls the disengagement of the rear wheel from its wheel-side clutch, the disengagement of the drive motor from the rear clutch, the engagement of the front wheel and its wheel-side clutch, and the control of The drive motor is engaged with the front clutch, and then the drive motor is controlled to drive the front wheels directly through the front drive reducer;

In one embodiment, the rear-wheel drive mode adopts the following control method: the vehicle controller controls the disengagement of the front wheel from its wheel-side clutch, the disengagement of the drive motor from the front clutch, the engagement of the rear wheel with its wheel-side clutch, and the control of The drive motor is engaged with the rear clutch, and then the drive motor is controlled to drive the rear wheel directly through the rear drive reducer;

In one of the embodiments, the following control methods are used in the simultaneous driving mode of the front and rear wheels: the vehicle controller controls the front wheel to engage with its wheel clutch, the drive motor to engage with the front clutch, and the rear wheel to engage with its wheel clutch. Engage, and control the drive motor and the rear clutch to engage, and then control the drive motor to directly drive the front wheels through the front drive reducer, and simultaneously drive the rear wheels through the rear drive reducer.

In one embodiment, when the vehicle controller determines that the actual load of the electric vehicle is less than the set load value, the vehicle controller needs to control the rear wheels and their wheel clutches after receiving the parking brake release signal. engage, and control the engagement of the drive motor and the rear clutch;

When the vehicle controller determines that the actual load of the electric vehicle is greater than or equal to the load setting value, the vehicle controller needs to control the rear wheel to engage and drive the rear wheel after receiving the parking brake release signal. The electric motor engages the rear clutch, the front wheel engages its side clutch, and the control drive motor engages the front clutch.

The invention has the following beneficial effects: the invention can flexibly control the starting and running of the vehicle according to the load of the vehicle, realizes the optimal control of the vehicle power, has better economy and handling stability, and enables the optimal utilization of the vehicle energy; The motor is driven and can automatically switch between four-wheel drive mode and other modes, which greatly reduces the weight and cost of the whole vehicle, can better transmit sufficient power to the road, and enhance the acceleration and off-road capabilities of the car.

Description of drawings

Fig. 1 is the structural representation of the electric vehicle of the present invention;

Fig. 2 is the drive system structure diagram of the electric vehicle of the present invention;

In the picture: 1. Wheel side clutch, 2. Front wheel, 3. Transmission shaft, 4. Front drive reducer, 5. Front clutch, 6. Drive motor, 7. Rear clutch, 8. Rear drive reducer, 9. Rear wheel, 10, Power battery, 11, Vehicle controller, 12, Motor controller, 13, Brake pedal, 14, Accelerator pedal, 15, Gear shifter, 16, Parking brake control device.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

1-2, a single motor four-wheel drive electric vehicle starting and driving control method, the electric vehicle includes a vehicle controller 11 and a drive motor 6, one end of the drive motor 6 passes through the front clutch 5 and the front drive The reducer 4 is connected, the other end is connected with the rear drive reducer 8 through the rear clutch 7, the front drive reducer 4 and the front wheel 2 are connected through the corresponding transmission shaft 3, and the rear drive reducer 8 and the rear wheel 9 through the corresponding The transmission shaft 3 is connected to the front wheel 2 and the rear wheel 9 is provided with a wheel side clutch 1; the control method includes the following steps:

1) The vehicle controller 11 controls the start of the electric vehicle according to the actual load of the electric vehicle;

When the vehicle controller 11 monitors the power allowable output signal and the driving gear signal, it determines whether the actual load of the electric vehicle is less than the load setting value, and the load setting value is 35% of the rated load of the electric vehicle;

If the actual load of the electric vehicle is less than the set load value, and after receiving the parking brake release signal, the vehicle controller 11 controls the rear wheels 9 to engage with their corresponding wheel clutches 1, and controls the drive motor 6 Engage with the rear clutch 7, and then control the drive motor 6 to run after monitoring that the accelerator pedal signal (voltage signal) reaches the first set signal value, and the drive motor 6 directly drives the corresponding drive shaft 3 to run through the rear drive reducer 8 The belt rear wheel 9 runs, thereby driving the electric vehicle to start and drive at a low speed;

The set value of the first signal is 0～3.5V;

If the actual load of the electric vehicle is greater than or equal to the load setting value, and after receiving the parking brake release signal, the vehicle controller 11 controls the rear wheel 9 to engage with its corresponding wheel clutch 1 to drive the motor 6 It is engaged with the rear clutch 8, the front wheel 5 is engaged with its corresponding wheel side clutch 1, and the drive motor 6 is controlled to be engaged with the front clutch 5, and then the control is performed after monitoring that the accelerator pedal signal reaches the second set signal value. The drive motor 6 runs, the drive motor 6 drives the corresponding transmission shaft 3 to run through the rear drive reducer 8 to drive the rear wheel 9 to run, and at the same time drives the corresponding transmission shaft 3 through the front drive reducer 4 to run to drive the front wheel 2 to run, In this way, the electric vehicle is driven to accelerate and start, that is, the electric vehicle can start in the four-wheel drive mode.

The set value of the second signal is 3.5-5V.

2) After the electric vehicle starts, the vehicle controller 11 re-controls the driving mode of the electric vehicle according to the actual load of the electric vehicle.

The front wheel drive mode adopts the following control methods: the vehicle controller 11 controls the rear wheel 9 and its corresponding wheel clutch 1 to disengage, the drive motor 6 and the rear clutch 7 are disengaged, the front wheel 2 and its corresponding wheel clutch 1 engage, and control the drive motor 6 to engage with the front clutch 5, and then control the drive motor 6 to drive the front wheel 2 to run directly through the front drive reducer 4 to drive the corresponding transmission shaft 3 to run;

The rear wheel drive mode adopts the following control methods: the vehicle controller 11 controls the front wheel 2 and its corresponding wheel clutch 1 to disengage, the drive motor 6 and the front clutch 5 are disengaged, the rear wheel 9 and its corresponding wheel clutch 1 engage, and control the drive motor 6 and the rear clutch 7 to engage, and then control the drive motor 6 to directly drive the corresponding drive shaft 3 to run through the rear drive reducer 8 to drive the rear wheel 9 to run;

The following control methods are adopted in the simultaneous driving mode of front and rear wheels (four-wheel drive): the vehicle controller 11 controls the front wheel 2 to engage with its corresponding wheel clutch 1, the drive motor 6 to engage the front clutch 5, and the rear wheel to engage. 9 is engaged with its corresponding wheel side clutch 1, and the control drive motor 6 is engaged with the rear clutch 7, and then the drive motor 6 is controlled to directly drive the corresponding transmission shaft 3 through the front drive reducer 4 to drive the front wheel 2 to run; , and at the same time drive the corresponding transmission shaft 3 to run through the rear drive reducer 8 to drive the rear wheel 9 to run.

In one embodiment, step 2) is specifically:

When the vehicle controller 11 detects that the actual load of the electric vehicle is less than 35% of the rated load, and detects that the accelerator pedal signal is less than 2.5V, the electric vehicle enters the front-wheel drive mode;

When the vehicle controller 11 monitors: 35% of the rated load of the electric vehicle≤the actual load of the electric vehicle＜75% of the rated load, and 2.5V≤accelerator pedal signal＜3.5V, the electric vehicle enters the rear-wheel drive mode;

When the vehicle controller 11 monitors that: 75% of the rated load of the electric vehicle≤the actual load of the electric vehicle≤rated load, and 3.5V≤accelerator pedal signal≤5V, the electric vehicle enters the simultaneous driving mode of the front and rear wheels.

In another embodiment, step 2) is specifically:

When the vehicle controller 11 detects that the actual load of the electric vehicle is less than 35% of the rated load, and the electric vehicle travels to the set speed, the electric vehicle enters the front-wheel drive mode;

When the vehicle controller 11 monitors that 35% of the rated load of the electric vehicle≤the actual load of the electric vehicle<75% of the rated load, and the electric vehicle travels to the set speed, the electric vehicle enters the rear-wheel drive mode;

When the vehicle controller 11 monitors that 75% of the rated load of the electric vehicle≤actual load≤rated load, and the electric vehicle travels to the set speed, the electric vehicle enters the simultaneous driving mode of the front wheels and the rear wheels.

In one of the embodiments, it is also possible to switch between the simultaneous driving mode of the front wheels and the rear wheels, the driving mode of the front wheels and the driving mode of the rear wheels according to the traveling speed and the accelerator pedal signal at the same time. For example, when the vehicle controller 11 detects that the actual load of the electric vehicle is less than 35% of the rated load, and meets the requirement that the electric vehicle travels to the set speed and detects that the accelerator pedal signal is less than 2.5V, the electric vehicle enters the front-wheel drive mode; The vehicle controller 11 monitors that 35% of the rated load of the electric vehicle ≤ the actual load of the electric vehicle < 75% of the rated load, and satisfies that when the electric vehicle travels to the set speed and monitors 2.5V ≤ the accelerator pedal signal < 3.5V, The electric vehicle enters the rear-wheel drive mode; the vehicle controller 11 monitors that 75% of the rated load of the electric vehicle≤actual load≤rated load, and meets the requirement that the electric vehicle travels to the set speed and monitors 3.5V≤accelerator pedal signal≤5V When the electric vehicle enters the front wheel and rear wheel drive mode at the same time.

The electric vehicle of this embodiment is driven by a single motor, and the combination/disengagement of the drive motor 6 with the front drive reducer 4 and the rear drive reducer 8 is directly controlled through a drive motor 6 and its connection/disengagement with the front clutch 5 and the rear clutch 7 / disengage, so as to directly control the operation of the front wheel 2 or the rear wheel 9, the control is reliable, and the weight and cost of the whole vehicle are greatly reduced; in addition, four-wheel drive can be realized, and the full weight of the car can be used as the adhesion pressure, so that the car's attachment The focus is significantly increased, the traction limit of the car is expanded, the power of the driving motor 6 can be better transmitted to each wheel, and the driving force burden of each driving wheel is reduced, so that it can be In the case of skidding), it is ensured that enough power is transmitted to the road surface, so that the car has strong acceleration and off-road ability, and makes the tire wear more uniform, which is beneficial to prolong the service life of the tire and improve the handling safety of the car.

This embodiment can flexibly control the starting and running of the vehicle according to the load of the vehicle, and automatically switch the two-wheel drive or four-wheel drive mode according to the actual load and driving speed of the vehicle, so as to realize the optimal control of the power of the vehicle and have better economy. The handling stability of the vehicle is improved, so that the energy of the vehicle can be used more rationally.

The above-mentioned embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention is subject to the claims.

Claims (9)

1. a single motor four-wheel drive electric vehicle starts and a driving control method, it is characterized in that, described electric vehicle comprises vehicle controller and a drive motor, and one end of described drive motor passes through front clutch and front drive reducer The other end is connected with the rear drive reducer through the rear clutch, the front drive reducer is connected with the front wheel, the rear drive reducer is connected with the rear wheel, and both the front wheel and the rear wheel are provided with There are wheel clutches; the method includes the following steps: 1) The vehicle controller controls the start of the electric vehicle according to the actual load of the electric vehicle; Described step 1) is specifically: When the vehicle controller monitors the power allowable output signal and the driving gear signal, it determines whether the actual load of the electric vehicle is less than the load setting value. If so, the vehicle controller controls the rear wheel to engage its wheel clutch, and Control the drive motor to engage with the rear clutch, and then control the drive motor to run after monitoring that the accelerator pedal signal reaches the first set signal value. The drive motor directly drives the rear wheels through the rear drive reducer to drive the electric vehicle to start and drive at low speed. ; If not, the vehicle controller controls the rear wheel to engage with its wheel clutch, the drive motor to engage the rear clutch, the front wheel to engage its wheel clutch, and the drive motor to engage the front clutch, and then After monitoring that the accelerator pedal signal reaches the second set signal value, the drive motor is controlled to run. The drive motor drives the rear wheel to run through the rear drive reducer, and simultaneously drives the front wheel to run through the front drive reducer to drive the electric vehicle to start; 2) After the electric vehicle starts, the vehicle controller controls the driving mode of the electric vehicle according to the actual load of the electric vehicle. 2 . The starting and running control method of a single-motor four-wheel drive electric vehicle according to claim 1 , wherein the step 1) is specifically: the load setting value is 35% of the rated load of the electric vehicle. 3 . 3 . The starting and running control method of a single-motor four-wheel drive electric vehicle according to claim 1 , wherein the value of the first set signal is 0-3.5V; the value of the second set signal is 0-3.5V. 4 . 3.5～5V. 4. the electric vehicle starting and driving control method of single-motor four-wheel drive as claimed in claim 1, is characterized in that, described step 2) is specially: When the vehicle controller detects that the actual load of the electric vehicle is less than 35% of the rated load, and the accelerator pedal signal is less than 2.5V, the electric vehicle enters the front-wheel drive mode; When the vehicle controller detects that 35% of the rated load of the electric vehicle ≤ actual load < 75% of the rated load, and monitors 2.5V ≤ accelerator pedal signal < 3.5V, the electric vehicle enters the rear-wheel drive mode; When the vehicle controller detects that 75% of the rated load of the electric vehicle≤actual load≤rated load, and monitors 3.5V≤accelerator pedal signal≤5V, the electric vehicle enters the simultaneous driving mode of front and rear wheels. 5. The electric vehicle starting and driving control method of single motor four-wheel drive as claimed in claim 1, is characterized in that, described step 2) is specially: When the vehicle controller detects that the actual load of the electric vehicle is less than 35% of the rated load, and the electric vehicle travels to the set speed, the electric vehicle enters the front-wheel drive mode; When the vehicle controller detects that 35% of the rated load of the electric vehicle ≤ actual load < 75% of the rated load, and the electric vehicle travels to the set speed, the electric vehicle enters the rear-wheel drive mode; When the vehicle controller detects that 75% of the rated load of the electric vehicle≤actual load≤rated load, and the electric vehicle travels to the set speed, the electric vehicle enters the simultaneous driving mode of the front and rear wheels. 6. The electric vehicle starting and driving control method of single-motor four-wheel drive according to any one of claims 1-5, wherein the front-wheel drive mode adopts the following control method: the vehicle controller controls the rear wheel and its The wheel side clutch is disengaged, the drive motor is disengaged from the rear clutch, the front wheel is engaged with its wheel side clutch, and the drive motor is controlled to engage with the front clutch, and then the drive motor is controlled to drive the front wheel directly through the front drive reducer. 7. The single-motor four-wheel-drive electric vehicle starting and driving control method according to any one of claims 1-5, wherein the rear-wheel drive mode adopts the following control method: the vehicle controller controls the front wheel and its The wheel side clutch is disengaged, the drive motor is disengaged from the front clutch, the rear wheel is engaged with its wheel side clutch, and the drive motor is controlled to engage with the rear clutch, and then the drive motor is controlled to drive the rear wheel to run directly through the rear drive reducer. 8. The electric vehicle starting and driving control method of single-motor four-wheel drive according to any one of claims 1-5, is characterized in that, the following control methods are adopted in the simultaneous driving mode of front wheel and rear wheel: The front wheel is engaged with its wheel side clutch, the drive motor is engaged with the front clutch, the rear wheel is engaged with its wheel side clutch, and the control drive motor is engaged with the rear clutch, and then the drive motor is controlled to drive the front drive directly through the front drive reducer. The wheels run, and at the same time, the rear wheels are driven to run through the rear drive reducer. 9. The electric vehicle starting and driving control method of single-motor four-wheel drive as claimed in claim 1, wherein when the vehicle controller judges that the actual load of the electric vehicle is less than the load setting value, the vehicle controller After receiving the parking brake release signal, it is necessary to control the engagement of the rear wheel and its wheel side clutch, and control the engagement of the drive motor and the rear clutch; When the vehicle controller determines that the actual load of the electric vehicle is greater than or equal to the load setting value, the vehicle controller needs to control the rear wheel to engage and drive the rear wheel after receiving the parking brake release signal. The electric motor engages the rear clutch, the front wheel engages its side clutch, and the control drive motor engages the front clutch.

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