Vehicle Drive Control Engine Stop Stability Feedback
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Solution Overview
Problem
On low-μ roads, vehicles exhibit unstable behavior when stopping or starting, leading to increased power consumption by electric power steering (EPS) due to difficulty in quickly charging the system during engine idling stop conditions, as existing technologies fail to appropriately supply power to equipment requiring it in such unstable states.
Innovation Solution
A vehicle drive control apparatus that includes an engine stop control unit and a behavior determination unit, which determines whether the vehicle's behavior is stable or unstable, preventing engine stoppage when instability is detected, and initiating engine start when necessary to ensure power supply to EPS and other control systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the engine is automatically stopped during vehicle stopping to suppress idling operation, then fuel economy is improved, but power supply to equipment requiring power (such as EPS) becomes insufficient when vehicle behavior is unstable
Solution Approach 1:
The control unit continuously monitors vehicle behavior stability through sensors (yaw rate, lateral acceleration, steering angle) and uses this feedback to dynamically adjust engine stop/start decisions. When instability is detected, the system feedbacks to prohibit engine stoppage, ensuring power supply reliability while maintaining fuel efficiency during stable conditions
Solution Approach 2:
The engine stop control is made dynamic by adjusting it based on real-time vehicle behavior conditions. The system transitions between stop and no-stop states depending on stability assessment, allowing the engine stop function to adapt to changing operational conditions rather than operating statically
2Loss of energy
If the engine is stopped during unstable vehicle behavior, then fuel economy is improved, but driver comfort deteriorates due to insufficient power supply to EPS
Solution Approach 1:
The system uses feedback from stability sensors to continuously assess whether engine stoppage would compromise steering assistance quality. When feedback indicates unstable behavior, the control unit prohibits engine stoppage, preventing degradation of steering responsiveness and maintaining driver comfort while still enabling fuel-saving stops during stable conditions
3Object-generated harmful factors
If the engine is automatically stopped during vehicle stopping, then emissions are reduced, but vehicle control capability deteriorates on low-μ surfaces
Solution Approach 1:
The system performs preliminary assessment of vehicle behavior stability before permitting engine stoppage. By evaluating yaw rate, lateral acceleration, and steering angle in advance, the control unit predicts whether engine stop would compromise control capability on low-μ surfaces, preventing stoppage when control reliability would deteriorate
Data Source
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AI summary
In a vehicle drive control apparatus, a behavior determination unit determines whether a vehicle behavior is in a stable state or an unstable state based on a vehicle turning behavior. An engine stop control unit avoids stopping the engine as automatic stop conditions are not satisfied when the vehicle behavior is determined to be in an unstable state during operation of the engine. When the vehicle behavior is in a stable state and other automatic stop conditions are satisfied during operation of the engine, the engine stop control unit stops the engine. During stability control performed by a stability ECU, the engine stop control unit avoids stopping the engine as the automatic stop conditions are not satisfied.