Parking Brake Release Timing via Predicted Torque
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle braking systems experience mechanical inertia delays when releasing the parking brake during vehicle startup, leading to potential starting against the brakes and increased wear, especially when the driver accelerates quickly.
Innovation Solution
Estimate the future engine torque and initiate the brake release process early enough to complete it just as the engine torque exceeds the required threshold for starting, accounting for braking system inertia and using driver input or assistance system data to determine the necessary timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the brake release process is initiated only when engine torque exceeds the threshold, then the brake release timing is simple to control, but the vehicle starts against the brakes causing increased wear and reduced acceleration
Solution Approach 1:
The brake release process is initiated in advance based on predicted engine torque that will exceed the threshold, rather than waiting for the threshold to be actually exceeded. This preliminary action accounts for the mechanical inertia delay, ensuring the brake is fully released before the vehicle starts moving, thereby preventing brake wear and poor acceleration while maintaining simple control logic through prediction algorithms
2Reliability
If the brake release process is delayed to account for mechanical inertia, then the vehicle does not start against the brakes, but the acceleration response becomes slower and less responsive to driver input
Solution Approach 1:
The system performs preliminary action by predicting future engine torque based on current accelerator pedal position and vehicle state. This allows the brake release to be timed precisely - starting early enough to account for mechanical inertia but not so early as to delay response to driver input. The prediction algorithm dynamically adjusts the timing to maintain both reliability and responsiveness
Solution Approach 2:
The brake release timing is made dynamic rather than fixed. The system continuously monitors accelerator pedal position, engine torque, and vehicle state to dynamically adjust when to initiate brake release. This dynamic adaptation allows the system to respond quickly to driver intentions while always accounting for the mechanical inertia of the brake system, achieving both fast response and smooth operation
Data Source
Figure 1~2
AI summary
The invention relates to a method for releasing a brake during a starting process of a vehicle. In order to prevent the vehicle from starting against the brake, the future motor torque or a value that is proportional thereto is estimated (2), and the point in time when the future motor torque or the value that is proportional thereto exceeds a specified threshold is ascertained (3). The release process of the brake is then started a specified period of time (?t) prior to the point in time (ts) when the threshold (SW) is exceeded.