Parking Brake Control Using Inactive-State and Speed Confirmation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional systems for preventing vehicle roll-away lack effectiveness in confirming the inactive state of a vehicle through multiple sources and fail to consider the vehicle's speed when determining whether to apply the parking brake, potentially leading to unintended braking during coasting or power failures.
Innovation Solution
A system and method that utilize multiple sources to confirm the vehicle's inactive state and consider its speed relative to a predetermined condition before automatically applying the parking brake, ensuring accurate and safe application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the parking brake is applied automatically based on a single source signal indicating inactive state, then the system responds quickly to prevent roll-away, but the reliability of state confirmation is insufficient
Solution Approach 1:
The system implements feedback by continuously monitoring multiple independent signals (ignition switch status, brake pedal position, clutch/brake switch signals) to confirm the vehicle's inactive state before automatically applying the parking brake. This multi-source feedback mechanism ensures reliable state detection while maintaining timely response.
Solution Approach 2:
The parking brake controller acts as an intermediary that receives and evaluates signals from multiple sources (ignition system, brake system, clutch system) before executing the parking brake application. This intermediary function ensures that automatic braking only occurs when all indicators confirm the vehicle should be stationary.
2Device complexity
If the parking brake is applied automatically without considering vehicle speed, then the system simplifies the control logic, but unintended braking may occur during coasting or power failures
Solution Approach 1:
The system changes the parameter consideration by incorporating vehicle speed (via wheel speed sensor or transmission output speed sensor) as an additional criterion for automatic parking brake application. The controller evaluates both the inactive state signals and speed parameters before executing braking, preventing unintended braking during coasting or power failure scenarios.
3Reliability
If multiple sources are used to confirm inactive state, then the reliability of state detection is improved, but the system complexity increases
Solution Approach 1:
The parking brake controller performs multiple functions: it monitors ignition switch status, brake pedal position, clutch/brake switch signals, and vehicle speed, then integrates all these inputs to make a single decision about parking brake application. This multi-functional approach consolidates complex monitoring into one control unit, managing system complexity while maintaining high reliability.
Data Source
AI summary
A system for braking a vehicle includes an operator interface that transmits a brake command signal when actuated by a vehicle operator. When the interface is not actuated and does not transmit the signal, a controller receives signals indicative of whether the vehicle is in an active or inactive state from two different sources and determines that the vehicle is in the inactive state if both of the signals indicate the vehicle is in the inactive state. The controller receives another signal indicative of a speed of the vehicle and determines whether the speed of the vehicle meets a predetermined condition relative to a predetermined speed of the vehicle. The controller generates a control signal to apply a wheel parking brake on the vehicle after determining that the vehicle is the inactive state and determining that the speed of the vehicle meets the predetermined condition relative to the predetermined speed.