Vehicle Motion Control Device for Curve Deceleration
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Solution Overview
Problem
Existing vehicle motion control systems fail to match the driver's feeling of slowdown, especially when decelerating on straight roads or before curves, due to their inability to handle time-varying changes in negative acceleration effectively, leading to mismatched deceleration and driver experience.
Innovation Solution
A vehicle motion control device that acquires curve shape and vehicle position data to compute longitudinal acceleration command values, allowing for time-varying changes in acceleration to match the driver's perception of slowdown by adjusting acceleration patterns based on curve curvature and vehicle position, even in the absence of lateral motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If constant negative acceleration is applied before the curve, then the total deceleration amount is controlled, but the deceleration does not match the driver's feeling of slowdown
Solution Approach 1:
The patent applies dynamics by transitioning from constant negative acceleration to time-varying negative acceleration. The system dynamically adjusts the acceleration command based on the vehicle's position relative to the curve, using a bell-shaped curve function that varies acceleration over time. This allows the deceleration profile to adapt to different driving scenarios and match driver expectations, resolving the contradiction between control precision and driver comfort.
Solution Approach 2:
The patent changes the acceleration parameter from a constant value to a time-varying value. By introducing a bell-shaped curve function that modulates the acceleration command based on position and time, the system transforms the fixed acceleration parameter into a dynamic one that evolves throughout the deceleration process, enabling better matching of driver's feeling of slowdown.
2Ease of operation
If time-varying changes in negative acceleration are implemented to match driver's feeling, then driver comfort is improved, but the system requires unfathomable matching workload and vast volumes of data
Solution Approach 1:
The system employs self-service by using the vehicle's own position information and pre-stored curve shape data to automatically generate the time-varying acceleration command. The bell-shaped curve function is computed based on real-time position feedback, eliminating the need for extensive manual matching workloads and large volumes of pre-collected data, thus reducing system complexity while maintaining driver comfort.
Solution Approach 2:
The patent replaces complex mechanical matching processes with computational methods. Instead of requiring extensive manual calibration and data collection, the system uses mathematical modeling (bell-shaped curve function) and real-time computation based on position feedback to generate appropriate acceleration profiles, significantly reducing the mechanical workload and data requirements.
3Reliability
If lateral jerk-based acceleration creation is used, then acceleration matches lateral motion, but it cannot create acceleration under no lateral motion conditions
Solution Approach 1:
The patent achieves universality by creating a acceleration command system that functions in both lateral motion and no lateral motion conditions. The bell-shaped curve-based time-varying acceleration command can be generated solely from position information and curve shape data, making it applicable whether the vehicle is currently experiencing lateral motion or not, thus expanding the system's adaptability while maintaining reliability.
Data Source
AI summary
A vehicle motion control device includes curve shape acquisition means for acquiring a shape of a curve present in front of a currently traveling vehicle, vehicle position acquisition means for acquiring a position of the vehicle, and vehicle motion control arithmetic means for computing, on the basis of the shape of the curve and the position of the vehicle, a command value relating to longitudinal acceleration to be caused to the vehicle. During a time interval from before the vehicle reaches a near end of the curve, until the vehicle has approached the curve and traveled to a site having a constant or maximum curvature of the curve, the vehicle motion control arithmetic means computes a plurality of different negative longitudinal acceleration command values. Thus, even when there is no lateral motion, the vehicle motion control device accelerates/decelerates the vehicle while improving a driver's feeling of slowdown.