Vehicle Coasting Deceleration Control Using Perceptual Risk Index
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Solution Overview
Problem
Existing vehicle control devices fail to set optimal deceleration during free running periods when a preceding vehicle is detected, as they do not account for driver-specific preferences regarding the timing of accelerator and brake operations, leading to potential mismatch between desired and actual deceleration magnitudes.
Innovation Solution
A control device that includes a deceleration control unit, an index deriving unit, and a relationship adjusting unit to derive and adjust deceleration based on a perceptual risk index, which differentiates between driver types and adjusts deceleration settings accordingly, ensuring the deceleration in the non-operation state aligns with driver preferences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the learning process is executed only when no preceding vehicle is detected or when distance is sufficient, then the deceleration can be learned without preceding vehicle influence, but the deceleration cannot be set to driver-preferred magnitude when preceding vehicle is present
Solution Approach 1:
The system changes the parameter of reference perceptual risk index dynamically based on driving conditions. When a preceding vehicle is detected, the reference perceptual risk index is adjusted to account for the driver's heightened awareness of potential collision risk, allowing the deceleration control to adapt to the changed driving environment while maintaining learning accuracy
Solution Approach 2:
The perceptual risk index serves as an intermediary parameter that bridges the gap between objective driving conditions (presence of preceding vehicle) and driver behavior (accelerator/brake operation timing). By using this intermediary, the system can infer driver preferences even when preceding vehicles are present, resolving the contradiction between learning accuracy and adaptability
2Adaptability or versatility
If the reference perceptual risk index is corrected based on transition phase perceptual risk index, then the deceleration control adapts to driver preferences, but the control system complexity increases
Solution Approach 1:
The perceptual risk index calculation unit performs multiple functions: it calculates the index based on driving conditions, compares it with the reference value, and uses the result to adjust the free running deceleration control. By making this single unit multi-functional, the system achieves adaptability without proportionally increasing overall system complexity
Data Source
AI summary
A control device includes: a deceleration control unit that performs a free running deceleration control that controls free running deceleration when transition occurs from an operation state to a non-operation state; an index deriving unit that derives a transition phase perceptual risk index; and a relationship adjusting unit that adjusts a relationship between a perceptual risk index and a deceleration. The deceleration control unit derives the deceleration corresponding to the transition phase perceptual risk index based on the relationship and sets the derived deceleration as the free running deceleration. The relationship adjusting unit executes a correction control in which when the transition phase perceptual risk index is larger than the reference perceptual risk index, the reference perceptual risk index is corrected to be increased, and when the transition phase perceptual risk index is smaller than the reference perceptual risk index, the reference perceptual risk index is corrected to be decreased.