Electronic Parking Brake Release Timing for Drag Torque Prevention
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Solution Overview
Problem
Conventional electronic parking brakes face issues with reduced release time due to increased fluid pressure, leading to excessive drag torque between brake pads and discs, which decreases fuel efficiency and causes premature wear of brake pads.
Innovation Solution
A method of controlling the electronic parking brake that involves determining and maintaining a sufficient no-load release time and minimum EPB release time to ensure a sufficient air gap between the brake pad and disc, by adjusting the motor current supply until both conditions are met, thereby preventing drag torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the release fluid pressure is increased to reduce the load release time, then the EPB release time is reduced, but the brake pad and brake disc do not separate sufficiently causing excessive drag torque
Solution Approach 1:
The system dynamically adjusts the no-load release time based on the release fluid pressure. When release fluid pressure increases and load release time decreases, the controller automatically extends the no-load release time to compensate, ensuring the total EPB release time maintains sufficient duration for complete brake pad separation and air gap formation, preventing excessive drag torque.
Solution Approach 2:
The controller changes the no-load release time parameter based on release fluid pressure conditions. By monitoring the release fluid pressure and calculating appropriate no-load release time values, the system adapts the temporal parameters to ensure sufficient brake pad separation regardless of varying hydraulic pressure conditions.
2Loss of time
If the EPB release time is reduced for faster response, then the vehicle responsiveness is improved, but fuel efficiency decreases due to excessive drag torque
Solution Approach 1:
The system uses feedback from release fluid pressure sensors to monitor actual brake release conditions. Based on this feedback, the controller calculates and adjusts the no-load release time to ensure sufficient brake pad separation, preventing drag torque that would waste energy and reduce fuel efficiency while maintaining fast response when conditions allow.
3Speed
If the EPB release time is reduced, then the response speed is improved, but brake pad wear increases due to insufficient air gap
Solution Approach 1:
The system performs preliminary action by extending the no-load release time phase before the load release time. This preliminary extension ensures that the brake pad has sufficient time to separate completely from the brake disc and form an adequate air gap before the vehicle begins moving, preventing premature wear while maintaining fast overall response.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively secures a sufficient air gap, improving fuel efficiency and preventing premature brake pad wear by ensuring the electronic parking brake release time is maintained for a predetermined duration.
Implementation Method 1
a motor, which is a power source configured to generate power
Implementation Method 2
bring a brake pad into close contact with a disk to generate a frictional braking force
Data Source
AI summary
A method of controlling an electronic parking brake includes: an initiation determination process of determining whether to initiate an electronic parking brake (EPB) release operation based on whether a release signal is input; a calculation process of calculating a no-load release time and a minimum EPB release time when the EPB release operation is initiated; a no-load release time adjustment process of measuring a time of a no-load section based on a current flowing through a motor and adjusting the time of the no-load section by supplying the current to the motor until the time of the no-load section is equal to the calculated no-load release time; and a release process of determining whether a summed time of a time of a load section and the adjusted time of the no-load section satisfies the minimum EPB release time, and continuously supplying the current to the motor to supply the current to the motor until the summed time becomes equal to the EPB release time when the summed time is less than the minimum EPB release time.