Controller Maintains Service Brake Pressure During Parking Transition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Commercial vehicles equipped with air brake systems are prone to rollaway during the transition from service brake to parking brake application, especially on grades and when carrying heavy loads, as the vehicle may start to roll before the parking brakes are fully engaged.
Innovation Solution
A controller system that receives service brake and parking brake signals, and transmits a control signal to maintain service brake engagement for a predetermined time period, ensuring the vehicle remains stable until the parking brakes are fully engaged, utilizing inputs from vehicle motion, load, and gradient sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the driver removes or reduces service brake application during the transition to parking brake, then the driver can operate the brakes more easily, but the vehicle begins to roll away during the transition period
Solution Approach 1:
The system performs preliminary action by detecting the driver's intent to release service brakes during parking brake transition and automatically maintaining service brake application until parking brakes are fully engaged. This preemptive control prevents rollaway before it can occur, resolving the contradiction between ease of operation and vehicle stability.
2Reliability
If the vehicle is on a grade or carrying heavy load, then the vehicle has higher stability requirements, but the rollaway tendency increases during brake transition
Solution Approach 1:
The system uses feedback from sensors detecting vehicle grade, load conditions, and brake system state to dynamically control service brake maintenance. When adverse conditions (grade or heavy load) are detected during parking brake transition, the system automatically maintains service brake application, creating a closed-loop control that adapts to environmental factors and prevents rollaway.
3Reliability
If the parking brake engagement time is extended to ensure full engagement, then the vehicle stability improves, but the time required to complete the parking maneuver increases
Solution Approach 1:
The system introduces an intermediary control mechanism that maintains service brake application during the parking brake engagement transition. This intermediary service brake support acts as a backup force that ensures vehicle stability throughout the transition period, allowing the parking brake to engage fully without compromising stability, thereby resolving the time-reliability tradeoff.
Data Source
AI summary
Various embodiments of a controller, system and method of preventing vehicle rollaway for a heavy vehicle are disclosed. The controller receives a service brake signal indicating an operator has engaged the service brakes, a parking brake signal indicating the operator intent to actuate the parking brake and a signal indicative of motion. The controller transmits a control signal to at least two braking system components in response the service brake signal, the parking brake signal, and the motion of the vehicle to maintain engagement of the vehicle service brakes after the service brake pressure signal begins to decrease.