Engine Start-Stop Control for Neutral Duration Restart
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Solution Overview
Problem
Auto start-stop systems in vehicles often fail to restart the engine correctly when the driver downshifts from a high gear to first gear while the transmission is still in neutral, leading to engine restart issues due to insufficient time in the neutral position.
Innovation Solution
Implementing a method where the engine restarts if the transmission has been in neutral for a predetermined period of time, allowing the clutch pedal to be depressed concurrently with the transition into an in-gear position, regardless of the brake pedal state, using a control unit with sensors to monitor and manage this process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the engine restarts only when the brake pedal is released, then the restart logic is simple, but the engine fails to restart reliably when the driver downshifts from high gear to first gear while the transmission is in neutral
Solution Approach 1:
The patent applies dynamics by making the engine restart criteria adaptive rather than static. The system dynamically evaluates multiple conditions including brake pedal state, transmission gear position, and duration in neutral position. This allows the restart logic to adapt to different driving scenarios (normal stop vs. downshift operation) improving reliability without requiring overly complex hard-wired logic
Solution Approach 2:
The patent implements feedback by continuously monitoring the transmission gear position and duration in neutral, then using this information to determine whether to trigger engine restart. The control unit receives feedback from sensors about pedal positions and transmission state, processes this information against predefined criteria, and adjusts the restart decision accordingly. This feedback mechanism enables reliable restart detection across various driver behaviors
2Speed
If the engine restarts immediately when transmission moves out of neutral, then the response is fast, but the engine may restart prematurely before the driver intends to move the vehicle
Solution Approach 1:
The patent applies preliminary action by requiring the transmission to be in neutral for a predetermined minimum duration before the engine will restart. This preliminary time requirement ensures that the driver has genuinely intended to stop the vehicle (by spending sufficient time in neutral) before the engine restarts, preventing premature or accidental restarts while still maintaining responsive restart when the condition is genuinely met
Solution Approach 2:
The system dynamically adjusts the restart timing based on the duration the transmission remains in neutral. Rather than a fixed immediate response or a fixed delayed response, the restart timing is dynamic - it occurs after the neutral duration threshold is met and the clutch is depressed, adapting to the actual driver behavior pattern observed
Data Source
AI summary
Methods and systems are provided for an engine. In one example, a method of operating an engine of a vehicle, the vehicle comprising a brake pedal, a clutch pedal and a transmission having a neutral position and at least one in-gear position, comprises starting the engine if either the brake pedal of the vehicle is released or the transmission has been in neutral for a predetermined period of time, and the clutch pedal of the vehicle is depressed concurrently with the transmission being moved out of the neutral position into an in-gear position.