Hybrid Vehicle Gradient Detection Control for Engine Start Timing
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Solution Overview
Problem
Hybrid vehicles face issues with engine start and stop timing due to changing road surface gradients, leading to incongruity and fuel wastage, as existing control systems struggle to accurately detect and respond to gradient changes, resulting in delayed engine starts and premature stops.
Innovation Solution
A control device for hybrid vehicles that includes a gradient detection unit, a gradient determination control unit, an engine start control unit, and a traveling state determination unit, which detects and holds gradient information for a predetermined time to ensure accurate engine starting and stopping, preventing unnecessary engine operations and reducing fuel consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If hysteresis for gradient is set to prevent hunting at engine start/stop, then engine starting stability is improved, but engine response timing deteriorates causing delayed starts and premature stops
Solution Approach 1:
The gradient detection unit detects road gradient in advance before engine start/stop decisions are made. The gradient information is stored and used to predict upcoming gradient changes, allowing the engine control to prepare in advance rather than reacting with delay. This preliminary detection resolves the contradiction by providing forward-looking information that eliminates the timing lag caused by hysteresis filtering.
Solution Approach 2:
The system dynamically adjusts engine start/stop control based on real-time gradient detection results. When a gradient is detected, the control unit modifies engine operation timing and parameters adaptively. This dynamic response allows the system to maintain stability through gradient-aware control while avoiding the fixed timing delays that would result from static hysteresis-based control alone.
2Measurement precision
If gradient detection threshold is set low for sensitive detection, then gradient detection accuracy is improved, but false detection increases causing unnecessary engine operations
Solution Approach 1:
The system uses feedback from the gradient detection unit to continuously monitor road gradient conditions. The detected gradient information feeds into the engine control unit, which adjusts engine operation accordingly. This closed-loop feedback mechanism ensures that engine operations are triggered only when actual gradient conditions warrant them, preventing false detections from causing unnecessary fuel consumption while maintaining sensitive detection through the feedback-controlled threshold adjustment.
Solution Approach 2:
By detecting gradient in advance and storing this information, the system can evaluate whether detected gradients represent genuine road conditions requiring engine operation or transient false signals. The preliminary detection allows for verification before triggering engine start/stop, reducing false operations and associated fuel waste while maintaining detection sensitivity.
Data Source
AI summary
A gradient determination control unit releases the hold of a gradient determination result when a state where a road surface gradient detected by a gradient detection unit is smaller than a gradient release determination threshold value continues for a second predetermined time or longer if a vehicle is determined to be in a traveling state by a traveling state determination unit, and releases the hold of the gradient determination result when the road surface gradient detected by the gradient detection unit becomes smaller than the gradient release determination threshold value if the vehicle is determined to be in a stopped state by the traveling state determination unit.