ESC Braking Control to Prevent Jerk on Sloped Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
When a vehicle is parked or stopped on a sloped surface using a parking brake, there is a time delay in the braking force activation, leading to a jerk due to the reduction in hydraulic pressure, causing discomfort to the driver and passengers.
Innovation Solution
A method utilizing an Electronic Stability Control (ESC) controller to calculate and apply a required braking torque to each wheel, considering longitudinal and lateral direction accelerations, and steering angle, to maintain a constant braking force and gradually reduce it to prevent jerk, thereby enhancing vehicle stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a parking brake is used to stop or park a vehicle on a sloped surface, then the vehicle can be held stationary, but a time delay occurs in braking force activation causing jerk
Solution Approach 1:
The ESC controller activates service brakes before the parking brake engages to pre-position the vehicle and compensate for the impending braking force reduction when the brake pedal is released. This preliminary action prevents the vehicle from moving during the time delay period, eliminating jerk while maintaining stopping stability.
Solution Approach 2:
The system applies counteracting braking force through the service brakes to offset the harmful effect of parking brake engagement delay. By applying preliminary anti-action in the form of compensatory braking torque, the system prevents the vehicle movement that would otherwise occur during the mechanical time interval, thereby preventing jerk.
2Ease of operation
If hydraulic pressure is reduced when the brake pedal is released, then the vehicle can resume normal operation, but the vehicle instantly moves backward due to time interval at wheels
Solution Approach 1:
The ESC controller continuously monitors vehicle speed, acceleration, and brake system status to detect when the brake pedal is released and when the vehicle is on a sloped surface. Based on this feedback, the controller automatically activates compensatory braking torque through the service brakes to maintain vehicle position stability during the hydraulic pressure reduction transition, preventing instantaneous backward movement.
3Productivity
If braking pressure is abruptly removed, then the brake system can reset for normal operation, but the vehicle experiences jerk and driver discomfort
Solution Approach 1:
Before the parking brake fully engages and before hydraulic pressure is completely removed, the ESC controller applies preliminary compensatory braking torque through the service brakes. This preliminary action ensures the vehicle remains stationary throughout the transition period, allowing the brake system to reset for normal operation without causing driver discomfort from jerk.
Data Source
AI summary
A method for controlling braking of a vehicle is configured to prevent a jerk which occurs when a driver removes his or her foot from a brake pedal when the vehicle is parked or stopped using a parking gear. The method is carried out such that a constant braking force is transferred to front and rear wheels, and braking pressure is gradually removed by using Electronic Stability Control (ESC) in consideration of a longitudinal direction acceleration in a state where the vehicle is parked or stopped.