ELECTRONIC PARKING BRAKE SYSTEM, ASSISTANT STARTING METHOD THEREOF FOR MOTOR VEHICLE

• US 20130073163A1
• Filed: 12/20/2010
• Published: 03/21/2013
• Est. Priority Date: 08/13/2010
• Status: Active Grant

• Current Assignee: WUHU Bethel Automotive Safety Systems Company Limited
• Original Assignee: WUHU Bethel Automotive Safety Systems Company Limited
• Inventors: Liu, Zhaoyong, Yuan, Yongbin, Gu, Qindong, Zhang, Sheng, Liu, Liping, Qiang, Yulin
• Granted Patent: US 8,948,965 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60T 7/042 by electrical means, e.g. using travel or force sensors
• CPC Class Codes: B60T 7/12 for automatic initiation; for initiation not subject to will of driver or passenger limiting speed of vehicles other than rail vehicles B60K31/00
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 10/182 including control of parking brakes
• CPC Class Codes: B60W 2510/0275 Clutch torque
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/14 Clutch pedal position
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill

Abstract

An electronic parking brake system and assistant starting method thereof for a motor vehicle are provided, wherein, the electronic parking brake system receives all sensor signals and detection signals of the motor vehicle; when any one of the following conditions is satisfied, the brake will be released to assist the driver in starting: condition (1): a torque T_c transmitted by a clutch is calculated, and the calculated torque T_c transmitted by the clutch is greater than a torque needed for starting the motor vehicle; condition (2): an engine rotate speed is greater than an engine idle speed, and an accelerator pedal and a clutch pedal are depressed simultaneously; condition (3): starting trend of the motor vehicle is detected; condition (4): the detected engine rotate speed is lower than a first predetermined threshold value calculated according to a throttle opening data; condition (5): a detected rotate speed or angle of driving wheel is greater than a predetermined threshold value of rotate speed or angle. In the application of the electronic parking brake system and assistant starting method thereof for a motor vehicle, there is no need to additionally a mount clutch position sensor and a gear position sensor; according to all the available sensor signals and detection signals on the motor vehicle, the system can accurately judge whether the brake can be automatically released, and there is no need to modify the existing motor vehicle, featuring low lost and accurate judgment.

Claims

1. An assistant starting method of electronic parking brake system for a motor vehicle, characterized in that, the electronic parking brake system receives all sensor signals and detection signals of the motor vehicle;

when any one of the following conditions is satisfied, the brake will be released to assist a driver in starting;

Condition (1);

a torque T_c transmitted by a clutch is calculated, and the calculated torque T_c transmitted by the clutch is greater than a torque T_n needed for starting the motor vehicle;

Condition (2);

an engine rotate speed is greater than an engine idle speed, and an accelerator pedal and a clutch pedal are depressed simultaneously;

Condition (3);

starting trend of the motor vehicle is detected;

Condition (4);

the detected engine rotate speed is lower than a first predetermined threshold value calculated according to a throttle opening data;

Condition (5);

a detected rotate speed or angle of a driving wheel is greater than a predetermined threshold value of rotate speed or angle.

2. The assistant starting method of electronic parking brake system for a motor vehicle of claim 1, characterized in that, the sensor signals received by the electronic parking brake system from the motor vehicle include the engine rotate speed signal obtained from the sensors on the engine and the effective torque signals output by the engine;

Under condition (1), the torque T_c transmitted by the clutch is calculated through the following equation (1);

3. The assistant starting method of electronic parking brake system for a motor vehicle of claim 2, characterized in that, when the sensor signals received by the electronic parking brake system from the motor vehicle include an acceleration signal, detect whether it also has received a reversing signal;

if no said reversing signal is received, according to the acceleration signal calculate an inclination α

between the current position of the motor and the horizontal plane;

according to the inclination α

, select the torque T_n required for starting under the corresponding condition (1).

4. The assistant starting method of electronic parking brake system for a motor vehicle of claim 3, characterized in that, the reversing signal is obtained by detecting the reversing light circuit.

5. The assistant starting method of electronic parking brake system for a motor vehicle of claim 1, characterized in that, the sensor signals received by the electronic parking brake system from the motor vehicle include a clutch pedal signal sent by the clutch position switch on the clutch pedal and an acceleration pedal signal sent by the acceleration pedal;

under the condition (2), when the electronic parking brake system has received the clutch pedal signal, it is judged that the clutch pedal is depressed;

when there is change in the acceleration pedal signal, it is judged that the acceleration pedal is depressed.

6. The assistant starting method of electronic parking brake system for a motor vehicle of claim 1, characterized in that, the sensor signals received by the electronic parking brake system from the motor vehicle include an acceleration signal;

under the condition (3), it is detected that the motor vehicle has the trend of starting through the following steps;

Step 31;

after having received the acceleration signal, the electronic parking brake system decomposes the acceleration signal into the sub-acceleration signals in X-axis and Z-axis directions in the vehicle body coordinate system;

Step 32;

compares the sub-acceleration signal in X-axis direction with the threshold value of acceleration;

Step 33;

when the sub-acceleration signal in the X-axis direction reaches the threshold value, it is judged that the motor vehicle has the trend of starting;

or, the sensor signals received by the electronic parking brake system from the motor vehicle include an acceleration signal, under the condition (3), it is detected that the motor vehicle has the trend of starting through the following steps;

Step 31′

;

after having received the acceleration signal, the electronic parking brake system decomposes the acceleration signal into the sub-acceleration signals in X-axis, Y-axis, Z-axis directions in the vehicle body coordinate system;

Step 32′

;

according to the sub-acceleration signals in the X-axis, Y-axis and Z-axis directions, obtain the current attitude data of the motor vehicle body;

Step 33′

;

compares the current attitude data of the motor vehicle body with the attitude data of the motor vehicle body in static state, so as to obtain the attitude change value of the motor vehicle body;

Step 34′

;

when the attitude change value of the motor vehicle body reaches a threshold value, it is judged that the motor vehicle has the trend of starting.

8. The assistant starting method of electronic parking brake system for a motor vehicle of claim 1, characterized in that, the sensor signals received by the electronic parking brake system from the motor vehicle include an engine rotate speed signal obtained by the speed sensor on the engine and a throttle valve signal obtained by the throttle valve position sensor on the throttle valve body;

under the condition (4), after having received the throttle valve signal, the electronic parking brake system calculates the first pre-determined threshold value according to the opening data represented by the throttle valve signal;

After having received the engine rotate speed signal, the electronic parking brake system compares the rotate speed of the engine with the first pre-determined threshold value;

when the rotate speed of the engine is less than the first pre-determined threshold value, the electronic parking brake system releases the braking

9. The assistant starting method of electronic parking brake system for a motor vehicle of claim 1, characterized in that, the brake is released in the following mode:

When the braking is completed by the parking brake system, and any of the conditions (1)-(5) is satisfied, the electronic parking brake system releases the braking;

when the braking is completed by the ESP system of the motor vehicle, and any of the conditions (1)-(5) is satisfied, the electronic parking brake system sends the command to release a braking pipeline pressure to the ESP system, and the ESP system will release braking

7. (canceled)

10. An electronic parking brake system for a motor vehicle, comprising an EPB controller and an actuating mechanism, characterized in that, the EPB controller also comprises a main control module and a CAN interface module, wherein the main control module includes a main control unit, a storage unit and one or more of calculation units;

wherein, the CAN interface module is designed to transmit signals or commands between the motor vehicle body CAN bus and the main control unit;

according to the received sensor signals or the detection signals, the main control unit judges the type of the sensor signals or the detection signals, selects the corresponding calculation unit to make calculation;

according to the calculated results obtained by the calculation unit or the sensor signals or detection signals received by the main control unit, the main control unit determines whether the current motor vehicle meets the condition for releasing the brake;

when the condition for releasing the brake is satisfied, the main control unit controls the actuating mechanism to operate and thus release the braking completed by the parking brake system;

or through the CAN interface module, the main control unit sends to the ESP system of the motor vehicle by way of the vehicle body CAN bus the command to release the braking pipeline pressure, so as to release the braking completed by ESP system;

according to the sensor signals or the detection signals sent by the main control unit as well as the relevant parameters in the storage unit, the one or more of calculation units make calculation, and the calculated results are provided to the main control unit to determine whether the condition for releasing brake is satisfied.

11. The electronic parking brake system for a motor vehicle of claim 10, characterized in that, the EPB controller also comprises an acceleration sensing circuit, wherein the acceleration sensing circuit is used to detect the acceleration of the motor vehicle and to send the detected acceleration signal to the main control unit.

12. The electronic parking brake system for a motor vehicle of claim 11, characterized in that, the EPB controller also comprises an electrical level matching circuit, wherein the electrical level matching circuit is connected with the reversing light circuit of the motor vehicle and is used to match the electrical level of the reversing signal transmitted from the reversing light circuit into an acceptable electrical level to the main control unit and to send the electrical acceptable level to the main control unit.

13. The electronic parking brake system for a motor vehicle of claim 12, characterized in that, one of the one or more of calculation units is a torque calculation unit, wherein the torque calculation unit is used to calculate the torque T_c transmitted by the clutch through the following equation (1):

14. The electronic parking brake system for a motor vehicle of claim 13, characterized in that, one of the one or more of calculation units is an inclination calculation unit and is used to calculate an inclination α

between the current position of the motor vehicle and the horizontal plane according to the acceleration signal.

15. The electronic parking brake system for a motor vehicle of claim 14, characterized in that, the storage unit stores the corresponding table of the torque T_n required for starting, the model of the motor vehicle, the inclination α

and the reversing signal etc.;

through this corresponding table, the main control module can select the torque T_n required for starting according to the current condition, the main control module compares the calculated results obtained by a torque calculation unit and the selected torque T_n required for starting;

when the torque T_c obtained by the torque calculation unit is greater than the torque T_n required for starting, it is judged that the current motor vehicle meets the condition for releasing brake.

16. The electronic parking brake system for a motor vehicle of claim 10, characterized in that, one of the one or more of calculation units is a sub-acceleration calculation unit, wherein the sub-acceleration calculation unit is used to decompose the received acceleration signal into sub-acceleration signals in X-axis and Z-axis directions in the vehicle body coordinate system.

17. The electronic parking brake system for a motor vehicle of claim 15, characterized in that, the threshold value of the sub-acceleration in X-axis direction is stored in the storage unit, which is provided to the main control unit to compare the sub-acceleration signal in X-axis direction with the threshold value;

when the sub-acceleration signal in the X-axis direction is greater than the threshold value, it is judged that the current motor vehicle meets the condition for releasing brake.

18. The electronic parking brake system for a motor vehicle of claim 11, characterized in that, one of the one or more of calculation units is a vehicle body attitude calculation unit, wherein the vehicle body attitude calculation unit decomposes the received acceleration signals into sub-acceleration signals in X-axis, Y-axis and Z-axis directions in the vehicle body coordinate system;

according to the sub-acceleration signals in X-axis, Y-axis and Z-axis, it is feasible to obtain the current attitude data of the motor vehicle body.

19. The electronic parking brake system for a motor vehicle of claim 18, characterized in that, the storage unit also stores the vehicle body attitude data when the motor vehicle in static state and the threshold value of the vehicle body attitude change value;

the main control unit compares the current attitude data with the vehicle body attitude data in static state;

when the vehicle body attitude change value reaches the threshold value, it is judged that the current motor vehicle meets the condition for releasing brake.

20. The electronic parking brake system for a motor vehicle of claim 10, characterized in that, the actuating mechanism comprises a braking motor and a speed reducing mechanism connected with the braking motor, wherein the braking motor receives a command from the main control unit, makes the corresponding action according to the command;

the speed reducing mechanism is connected with the parking brake.

21. The electronic parking brake system for a motor vehicle of claim 11, characterized in that, all sensor signals or detection signals received by the CAN interface module from the vehicle body CAN bus, include a clutch pedal signal and an acceleration pedal signal, or an acceleration signal, or an engine rotate speed signal and a throttle position signal, or a wheel speed or rotate angle signal of the driving wheel.