Engine Restart Control via Dual Method Selection
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Solution Overview
Problem
Existing restart methods for internal combustion engines in vehicles equipped with idle reduction coasting technology are not always reliable, as they may fail to ensure engine restart while the vehicle is coasting at high speeds, especially when rotational variations are high or low.
Innovation Solution
A restart control device that includes a performing-condition determining portion, a coasting portion, a restart-condition determining portion, a push-start portion, a start-up portion, and a doubly start-up portion, which uses a combination of clutch engagement and electric motor assistance to increase engine rotation speed and restart the engine, ensuring successful restart through multiple attempts if initial methods fail.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine is stopped during coasting to improve fuel economy, then fuel efficiency is improved, but the reliability of engine restart is worsened
Solution Approach 1:
The system dynamically switches between two restart methods (push-start and starter motor) based on real-time detection of rotational variation magnitude. When rotational variation is large, push-start is used; when rotational variation is small, starter motor is used. This dynamic adaptation ensures reliable restart under varying coasting conditions while maintaining fuel economy benefits.
Solution Approach 2:
The control device changes the restart method parameter based on the detected rotational variation parameter. By monitoring the magnitude of rotational variation and selecting different restart approaches accordingly, the system optimizes restart reliability across different operating conditions without compromising fuel economy during coasting.
2Device complexity
If only push-start method is used for engine restart, then device complexity is reduced, but the reliability of engine restart is worsened
Solution Approach 1:
The restart control device incorporates two restart methods (push-start and starter motor) within a single integrated system. The control unit universally manages both methods and selects the appropriate one based on rotational variation detection, ensuring reliable restart while avoiding the need for separate independent control systems.
3Device complexity
If only starter motor is used for engine restart, then device complexity is reduced, but the reliability of engine restart is worsened
Solution Approach 1:
The restart control device incorporates two restart methods (push-start and starter motor) within a single integrated system. The control unit universally manages both methods and selects the appropriate one based on rotational variation detection, ensuring reliable restart while avoiding the need for separate independent control systems.
4Ease of operation
If rotational variation threshold is set high to enable push-start, then ease of operation is improved, but the reliability of engine restart is worsened
Solution Approach 1:
The system dynamically adjusts the operational mode based on real-time rotational variation detection. Instead of using a fixed high threshold that limits push-start availability, the control unit continuously monitors rotational variation and selects the appropriate restart method, ensuring both ease of operation and restart reliability across varying conditions.
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 restart control device ensures reliable engine restart during coasting by using dual methods to increase engine rotation speed, either through clutch engagement or electric motor assistance, thereby preventing restart failures and maintaining vehicle drivability without shocks or drivability deterioration.
Implementation Method 1
an electric motor which is connected to an output shaft of the internal combustion engine so that a torque is applied to the output shaft to increase a rotation speed of the internal combustion engine
Implementation Method 2
a clutch device which is engaged or disengaged to permit or prohibit a power transmission between the output shaft of the internal combustion engine and the driving wheel
Implementation Method 3
a push-start portion which engages the clutch device to increase a rotation speed of the internal combustion engine by a driving force generated by the coasting
Data Source
AI summary
A restart control device is applied to a vehicle which is provided with an internal combustion engine, an electric motor, a driving wheel, and a clutch. The restart control device has a restart-condition determining portion which determines whether a restart condition for restarting the internal combustion engine is established while the vehicle is coasting; a push-start portion which starts the internal combustion engine by a push-start; a start-up portion which starts the internal combustion engine by use of an electric motor; and a doubly start-up portion which tries to start the internal combustion engine by one of the push-start portion and the start-up portion when the restart-condition determining portion determines that the restart condition is established. The doubly start-up portion tries to start the internal combustion engine by another one of the push-up portion and the start-up portion when the internal combustion engine has not been started.