CN115447547A - Active braking and automatic parking control method based on double-loop brake master cylinder - Google Patents

Abstract

The invention discloses an active braking and automatic parking control method based on a double-circuit brake master cylinder. The invention can respond to active braking and automatic parking in time, has simple and efficient control process and ensures the braking and parking safety of the vehicle.

Description

Active braking and automatic parking control method based on double-loop brake master cylinder

Technical Field

The invention relates to the field of vehicle braking, in particular to an active braking and automatic parking control method based on a double-loop brake master cylinder.

Background

Along with the development of society and the popularization of automobiles, road safety attracts more and more attention of people, besides normal passive safety of automobiles, active safety also becomes a key point of industry discussion, particularly for trucks, driving fatigue often causes dispersed attention of drivers, and various dangers can be caused, and the active safety function can effectively reduce or even avoid the dangers.

Active safety mainly comprises active braking and automatic parking, and at present, for the control of the active braking and the automatic parking, on one hand, the control operation is too complicated due to the addition of too many parts; on the other hand, the control is not timely, the reaction speed is slow, and the safety and reliability are low.

Therefore, there is a need for an active braking and automatic parking control method based on a dual-circuit master cylinder, which can solve the above problems.

Disclosure of Invention

In view of the above, the present invention aims to overcome the defects in the prior art, and provides an active braking and automatic parking control method based on a dual-circuit brake master cylinder, which can respond to active braking and automatic parking in time, has a simple and efficient control process, and ensures the braking and parking safety of a vehicle.

The invention relates to an active braking and automatic parking control method based on a dual-loop brake master cylinder, wherein the dual-loop brake master cylinder comprises a brake-by-wire master cylinder and a vacuum booster master cylinder; a first brake oil path and the second brake oil path are arranged between the brake-by-wire master cylinder and the vacuum booster master cylinder; the method comprises the following steps:

a first specific valve is arranged on the first brake oil path, and a second specific valve is arranged on the second brake oil path;

the active braking is carried out according to the following method:

calculating the distance between an obstacle on a vehicle running route and the vehicle in real time, if the distance is smaller than a safe distance, performing master cylinder pressurization by the brake-by-wire master cylinder, simultaneously controlling a first specific valve and a second specific valve to close an oil circuit connection between the brake-by-wire master cylinder and a vacuum booster master cylinder, and controlling a motor to cancel driving torque by a vehicle control unit to convert the driving torque into feedback torque;

automatic parking is performed as follows:

when the brake pedal is stepped to a certain opening and the vehicle is completely static, if the opening of the brake pedal is increased again, the brake-by-wire brake master cylinder actively boosts to brake the four brakes and sends a command to cancel the driving torque of the motor, so that the vehicle is kept in a parking state;

when the brake-by-wire master cylinder does not recognize the brake signal and recognizes the accelerator signal, the brake-by-wire master cylinder quits working and the specific valve is switched, so that the vehicle is switched to a normal braking state.

Further, in the initiative braking, still include: if the distance is larger than the safe distance but gradually approaches the safe distance, the vehicle control unit controls the instrument to send out prompt information.

Further, in the initiative brake, still include: to prevent the vehicle from backing after stopping, the torque of the motor will become 0 when the wheel speed is zero.

Further, in the automatic parking, the method further includes: when the parking switch sends a parking signal, the brake-by-wire master cylinder can also actively pressurize to brake the four brakes, so that the vehicle is kept in a parking state.

Further, still include:

normal braking was performed as follows:

during normal braking, the brake pedal is connected with the brake master cylinder of the vacuum booster, the first specific valve and the second specific valve are controlled to close the oil way connection between the brake master cylinder of the vacuum booster and the brake-by-wire master cylinder, and hydraulic energy is transmitted to the brake during normal braking.

The beneficial effects of the invention are: the invention discloses an active braking and automatic parking control method based on a dual-loop brake master cylinder. The invention can respond to active braking and automatic parking in time, has simple and efficient control process and ensures the braking and parking safety of the vehicle.

Drawings

The invention is further described below with reference to the following figures and examples:

FIG. 1 is a schematic diagram of the overall vehicle control principle of the present invention;

FIG. 2 is a schematic view of the normal braking principle of the present invention;

FIG. 3 is a schematic diagram of the active braking principle of the present invention;

fig. 4 is a schematic view of the automatic parking principle of the present invention.

Detailed Description

The invention is further described with reference to the accompanying drawings, in which:

the invention relates to an active braking and automatic parking control method based on a dual-loop brake master cylinder, wherein the dual-loop brake master cylinder comprises a brake-by-wire master cylinder and a vacuum booster master cylinder which are mutually independent; the two main cylinders are connected to the oil circuit of the whole vehicle, and a first brake oil circuit and a second brake oil circuit are arranged between the brake-by-wire master cylinder and the brake master cylinder of the vacuum booster; the method comprises the following steps:

as shown in fig. 1, a first specific valve is provided in the first brake oil passage, and a second specific valve is provided in the second brake oil passage; the brake by wire master cylinder and the liquid storage pot of the vacuum booster master cylinder are connected through a hose, the arranged first specific valve and the second specific valve do not influence the transmission of hydraulic pressure, and meanwhile, the whole vehicle controller identifies the state of a brake pedal and controls the motor to feed back. The first specific valve is a specific valve for controlling a front brake oil path, the second specific valve is a specific valve for controlling a rear brake oil path, and the first specific valve and the second specific valve both adopt the existing switch valves, which is not described herein again;

the active braking is carried out according to the following method:

calculating the distance between a barrier on a vehicle running route and the vehicle in real time, if the distance is smaller than a safety distance, performing main cylinder pressurization by the brake-by-wire master cylinder, simultaneously controlling a first specific valve and a second specific valve to close an oil circuit connection between the brake-by-wire master cylinder and a vacuum booster master cylinder, and controlling a motor to cancel driving torque by a vehicle control unit to convert the driving torque into feedback torque; wherein, the schematic diagram of the control principle for performing active braking is shown in fig. 3; detecting and calculating the distance between an obstacle on a vehicle running route and the vehicle by arranging a millimeter wave radar and a camera; the millimeter wave radar and the camera are both in communication connection with the brake-by-wire master cylinder; the safety distance can be set according to actual working conditions; by closing the oil path connection between the brake-by-wire master cylinder and the vacuum booster master cylinder, pressure relief can be prevented, and active braking can be realized after pressure intensity is transmitted to the brake.

Automatic parking is performed as follows:

when the brake pedal is stepped to a certain opening and the vehicle is completely static, if the opening of the brake pedal is increased again, the brake-by-wire brake master cylinder actively boosts to brake the four brakes and sends a command to cancel the driving torque of the motor, so that the vehicle is kept in a parking state;

when the brake-by-wire master cylinder does not recognize the brake signal and recognizes the accelerator signal, the brake-by-wire master cylinder quits working and the specific valve is switched, so that the vehicle is switched to a normal braking state. Fig. 4 is a schematic diagram of a control principle for performing automatic parking.

In this embodiment, in the active brake, still include: and if the distance is greater than the safety distance but gradually approaches the safety distance, the vehicle control unit controls the instrument to send out prompt information. Therefore, the vehicle can timely give out early warning in the process of gradually approaching to the barrier or other vehicles, and preparation is made for active braking.

In this embodiment, in the active brake, still include: to prevent the vehicle from backing up after stopping, the motor torque will become 0 when the wheel speed is zero. Thereby ensuring the safety and stability of the active brake.

In the present embodiment, in the automatic parking, the method further includes: after the parking switch sends a parking signal, the brake-by-wire master cylinder also can actively pressurize to brake the four brakes, so that the vehicle is kept in a parking state. Therefore, the vehicle has higher automatic parking sensitivity, the timeliness of automatic parking is guaranteed, and the reliability of automatic parking is improved.

In this embodiment, the control method of the present invention further includes:

normal braking was performed as follows:

during normal braking, the brake pedal is connected with the brake master cylinder of the vacuum booster, the first specific valve and the second specific valve are controlled to close the oil way connection between the brake master cylinder of the vacuum booster and the brake-by-wire master cylinder, and hydraulic energy is transmitted to the brake during normal braking. Fig. 2 shows a schematic diagram of a control principle for performing normal braking.

Finally, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (5)

1. An active braking and automatic parking control method based on a dual-loop brake master cylinder comprises a brake-by-wire master cylinder and a vacuum booster master cylinder; a first brake oil path and the second brake oil path are arranged between the brake-by-wire master cylinder and the vacuum booster master cylinder; the method is characterized in that: the method comprises the following steps:

a first specific valve is arranged on the first brake oil path, and a second specific valve is arranged on the second brake oil path;

the active braking is carried out according to the following method:

calculating the distance between a barrier on a vehicle running route and the vehicle in real time, if the distance is smaller than a safety distance, performing main cylinder pressurization by the brake-by-wire master cylinder, simultaneously controlling a first specific valve and a second specific valve to close an oil circuit connection between the brake-by-wire master cylinder and a vacuum booster master cylinder, and controlling a motor to cancel driving torque by a vehicle control unit to convert the driving torque into feedback torque;

automatic parking is performed as follows:

when the brake pedal is stepped to a certain opening and the vehicle is completely static, if the opening of the brake pedal is increased again, the brake-by-wire brake master cylinder actively boosts to brake the four brakes and sends a command to cancel the driving torque of the motor, so that the vehicle is kept in a parking state;

when the brake-by-wire master cylinder does not recognize the brake signal and recognizes the accelerator signal, the brake-by-wire master cylinder quits working and the specific valve is switched, so that the vehicle is switched to a normal braking state.

2. The active braking and automatic parking control method based on the dual-circuit master cylinder according to claim 1, wherein: in the initiative braking, still include: and if the distance is greater than the safety distance but gradually approaches the safety distance, the vehicle control unit controls the instrument to send out prompt information.

3. The active braking and automatic parking control method based on the dual-circuit master cylinder as claimed in claim 1, wherein: in the initiative braking, still include: to prevent the vehicle from backing up after stopping, the motor torque will become 0 when the wheel speed is zero.

4. The active braking and automatic parking control method based on the dual-circuit master cylinder as claimed in claim 1, wherein: in the automatic parking, further comprising: after the parking switch sends a parking signal, the brake-by-wire master cylinder also can actively pressurize to brake the four brakes, so that the vehicle is kept in a parking state.

5. The active braking and automatic parking control method based on the dual-circuit master cylinder as claimed in claim 1, wherein: further comprising:

normal braking was performed as follows:

during normal braking, the brake pedal is connected with the brake master cylinder of the vacuum booster, the first specific valve and the second specific valve are controlled to close the oil way connection between the brake master cylinder of the vacuum booster and the brake-by-wire master cylinder, and hydraulic energy is transmitted to the brake during normal braking.

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