Hill Start Aid Controller Prevents Vehicle Roll on Inclines
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Solution Overview
Problem
Existing Hill Start Aide systems for vehicles fail to effectively manage brake engagement and disengagement on inclines, particularly when the driver releases the manual brake actuator, leading to potential vehicle roll and stress on the drivetrain, especially when coasting uphill or downhill.
Innovation Solution
A Hill Start Aide system that includes a controller communicating with the transmission and brake system, using sensors for ground speed, wheel speed, and grade detection to maintain brake pressure when the vehicle is stationary on an incline and release it when the driver intends to move, ensuring the vehicle starts in the desired direction without rolling, by manipulating the brake control valve and managing brake fluid pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the driver releases the manual brake actuator on an incline, then the brake is disengaged allowing vehicle movement, but the vehicle may roll in the opposite direction causing drivetrain stress
Solution Approach 1:
The system applies preliminary action by automatically maintaining brake engagement after the driver releases the manual brake actuator, preventing unwanted vehicle roll before the driver can potentially cause drivetrain stress by reversing direction
2Stability of the object's composition
If the system maintains brake pressure to prevent vehicle roll, then vehicle stability is improved, but the brake system remains engaged longer than necessary reducing operational flexibility
Solution Approach 1:
The system uses feedback by continuously monitoring transmission range (neutral vs. non-neutral) to dynamically control brake disengagement timing, ensuring brake pressure is maintained only when necessary for stability and released when the vehicle is ready to move
Solution Approach 2:
The system applies dynamics by making the brake control adaptive rather than static - the brake disengagement is dynamically controlled based on real-time transmission range conditions, allowing the system to adjust brake pressure timing to balance stability and operational flexibility
3Speed
If the brake is released immediately when the driver intends to move, then response time is improved, but the vehicle may roll on inclines before movement begins
Solution Approach 1:
The system prevents unwanted vehicle roll by maintaining brake engagement as a preliminary action before the driver releases the brake actuator, ensuring vehicle position stability is maintained during the transition period
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively prevents vehicle roll on inclines by maintaining brake engagement until the driver intends to move, reducing drivetrain stress and ensuring smooth starting and stopping, even when coasting uphill or downhill.
Implementation Method 1
Many Hill Start Aide systems operate to maintain a hydraulic pressure within vehicle brake lines that supply fluid pressure to wheel cylinders for slowing and/or stopping vehicle road wheels that contact the ground
Implementation Method 2
The grade sensor detects an angle of incline of the vehicle and provides an input to the controller indicative of whether the vehicle will tend to move when the brakes are released
Data Source
AI summary
An exemplary embodiment of a Hill Start Aide system for a vehicle includes a brake system. The brake system including a brake actuator for manually actuating the brake system. The brake system is selectively configurable in a stopped configuration, where the brake system is manually maintained via the brake actuator such that a vehicle road wheel speed is about zero rpm, a released configuration, where the brake system will not generally inhibit rotation of at least one vehicle road wheel, and a control stop configuration, where the vehicle road wheel speed is about zero rpm. The Hill Start Aide system also includes a controller for at least partially controlling the brake system. The controller will selectively send a signal to maintain the brake system in the control stopped configuration when the brake actuator is manually released. The controller will send a signal to the brake system to release the brakes when a predetermined amount of time has elapsed after a transmission is manually shifted to a neutral configuration while the brake system is in the control stopped configuration.