Parking Brake Force Feedback Using Pad-Integrated Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Standard electronic parking brake (EPB) systems operate in open loop, leading to force loss due to brake pad thickness variations and vehicle weight changes, particularly on inclined surfaces, resulting in over-designed systems that can damage brake components due to repeated high forces.
Innovation Solution
A vehicle electronic system with a parking brake equipment featuring sensors for real-time temperature, normal force, and shear force measurements, coupled with an actuator and controller in a closed-loop system, adjusts braking force to compensate for variations and includes an accelerometer and/or inclinometer for incline detection, ensuring consistent braking performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If open loop control strategy is used in standard EPB, then the system is simpler to implement, but the braking force cannot be adjusted in real-time to compensate for pad thickness variations and weight changes
Solution Approach 1:
The patent implements a closed-loop control system that continuously measures actual braking force using strain gauge sensors and compares it with the desired braking force. The controller adjusts the actuator output in real-time based on the feedback signal, compensating for pad thickness variations, weight changes, and thermal expansion effects. This feedback mechanism ensures consistent braking performance while avoiding excessive re-clamping forces.
2Reliability
If periodical force re-application with overestimated forces is used, then the vehicle remains stationary on inclined surfaces, but the repeated high forces weaken and damage the brake pads
Solution Approach 1:
The patent employs dynamic adjustment of braking force based on real-time measurements of actual versus desired braking force. Instead of applying fixed overestimated forces periodically, the system continuously modulates the actuator output to maintain the exact required braking force. This dynamic control prevents vehicle slip on inclined surfaces while minimizing mechanical stress on brake pads, thereby extending their service life.
3Reliability
If the EPB system is designed with overestimated size and number of re-clamping operations, then force loss due to temperature cooling and weight variation is compensated, but the system becomes more complex and causes greater wear
Solution Approach 1:
The patent replaces the traditional mechanical open-loop EPB system with an electronic closed-loop control system. Strain gauge sensors provide electrical measurements of actual braking force, which are processed by an electronic controller that dynamically adjusts actuator output. This substitution of mechanical estimation with electronic sensing and control eliminates the need for overdesign, reducing system complexity while ensuring sufficient braking force under all operating conditions.
Data Source
AI summary
A vehicle electronic system including a parking brake equipment, comprising a brake element (2) including either a brake pad or a brake shoe, said brake element (2) including an electrical circuit equipped with one or more sensors (3, 4, 5) for real-time detection of signals relating to temperatures and/or to normal forces and/or to shear forces and having electrical terminals arranged in a zone for collecting the signals from the brake element, said vehicle electronic parking brake system further comprising an actuator (8) of the brake element (2), a controller (7) delivering a braking force command to the actuator (8), and regulating means (9, 10) driving the controller (7), wherein the regulating means (9, 10) include a closed regulating loop of the braking force including a reference braking force generator (10), said closed regulating loop of the braking force being communicating with said sensors (3, 4, 5) to acquire at least one of temperatures and/or normal forces and/or shear forces measurements.