Vehicle Clutch Control for Faster Engine Restart During Coasting
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Solution Overview
Problem
Existing vehicle control systems experience delays in engine activation in response to accelerator operations, leading to uncomfortable driving experiences due to inefficient clutch engagement and hydraulic pressure management during coasting.
Innovation Solution
A control device that includes a controller to manage clutch engagement and engine activation by stopping fuel supply and releasing the clutch when the accelerator is off, then re-engaging the clutch with hydraulic pressure when the engine rotation exceeds a certain speed, and activating the engine after it stops, ensuring quick engine restart.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the clutch is engaged quickly when the accelerator is operated during coasting, then the vehicle accelerates faster, but the engine may be dragged by the clutch and fail to stop rotating properly, delaying activation
Solution Approach 1:
The clutch is released in advance during coasting to bring the engine rotation speed down to a first rotation speed or lower before accelerator operation. This preliminary action ensures that when the accelerator is pressed, the engine can stop rotating quickly and activate without delay, preventing the driver from feeling uncomfortable during acceleration.
2Productivity
If the engine is activated quickly in response to accelerator operation, then vehicle acceleration improves, but the clutch engagement timing becomes critical to avoid engine drag
Solution Approach 1:
The system changes the rotation speed parameter of the engine during coasting by releasing the clutch to reduce engine rotation speed to a first rotation speed or lower. This parameter change enables quick engine activation when the accelerator is operated, improving response speed while managing control complexity through automated controller logic.
3Use of energy by moving object
If the clutch remains engaged during coasting, then the engine can be activated quickly, but fuel consumption increases and the vehicle cannot coast efficiently
Solution Approach 1:
The clutch engagement state is dynamically changed during coasting - the clutch is released to allow the engine to rotate down to a first rotation speed or lower, enabling fuel-efficient coasting. When the accelerator is operated, the clutch is re-engaged at the appropriate timing to provide quick acceleration response, optimizing both fuel consumption and acceleration performance.
Data Source
AI summary
A control device for a vehicle is used in a vehicle that travels by transmitting a driving force from an engine to a drive wheel via a clutch. The control device includes a controller configured to perform an engine stop control in which, when an accelerator is not operated while the vehicle is traveling, a supply of a fuel to the engine is stopped and the clutch is released to enter a driving force cut-off state; a first control in which, when the accelerator is operated while the engine has a rotation speed higher than a first rotation speed in the driving force cut-off state, the engine is activated and the clutch has a torque transmission capacity; and a second control in which, when the accelerator is operated while the engine has the rotation speed equal to or lower than the first rotation speed in the driving force cut-off state, the engine is activated after the engine stops and the clutch has the torque transmission capacity after the engine is activated.