Vehicle Rollback Control via Driveline Decoupling and Speed Verification
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Solution Overview
Problem
Current motor vehicle control systems fail to effectively manage torque loading on the prime mover when stationary, leading to inefficiencies and potential rollback issues, especially in scenarios like steep inclines or when pre-loading the driveline for rapid acceleration.
Innovation Solution
A control system that selectively connects and disconnects the transmission from the prime mover based on brake engagement and release, verifying driveline speed to ensure safe release and prevent rollback, while also managing torque demand through accelerator control and automatic systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the transmission is disconnected from the prime mover when the vehicle is stationary, then torque loading on the prime mover is reduced, but the risk of vehicle rollback increases
Solution Approach 1:
The control system verifies that the driveline is rotating at sufficient speed before permitting brake release, ensuring the transmission is properly engaged and torque can be transmitted before the vehicle begins moving. This preliminary verification action prevents rollback while allowing the transmission to remain disconnected during stationary periods.
Solution Approach 2:
The control system continuously monitors driveline rotation speed and provides feedback to the brake release permission logic. This feedback mechanism ensures that the transmission connection status is verified in real-time, preventing brake release until proper engagement is confirmed, thus resolving the contradiction between energy savings and rollback prevention.
2Reliability
If the driveline is verified to be rotating at sufficient speed before brake release, then rollback is prevented, but the time required for safe vehicle启动 increases
Solution Approach 1:
The control system performs the driveline rotation verification as a preliminary check that occurs automatically in the background before the driver needs to release the brake. By preparing and verifying the driveline status in advance, the system minimizes the actual delay experienced by the driver during vehicle启动.
3Speed
If the transmission remains connected to the prime mover when stationary, then vehicle启动 response is improved, but torque loading on the prime mover increases
Solution Approach 1:
The control system dynamically adjusts the transmission connection status based on real-time operating conditions. The transmission is disconnected when stationary to save energy, but automatically reconnected when vehicle启动 is required, as determined by the driveline rotation speed verification. This dynamic adjustment resolves the contradiction between energy efficiency and启动 response.
Data Source
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AI summary
In one aspect of the invention there is provided a control system for a vehicle, the vehicle having a powertrain comprising a prime mover and a driveline, the control system being configured selectively to control the driveline to assume a first state in which a transmission of the driveline is substantially fully connected to the prime mover and a second state in which when the vehicle is stationary the transmission is at least partially disconnected or decoupled from the prime mover thereby to reduce a torque loading on the prime mover, the control system being configured to control the driveline to assume the second state when the vehicle is held stationary by brake means in response to actuation of driver operable brake control means, the control system being operable upon release of the brake control means to verify that a first portion of a powertrain of the vehicle is rotating at a speed exceeding a prescribed threshold and to command the driveline to assume the first state before permitting release of the brake means.