Vehicle Path Control Device Using Curvature Anticipation
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Solution Overview
Problem
Existing systems for real-time vehicle trajectory control, particularly for autonomous vehicles, face challenges in efficiently navigating curves with high curvature, as they struggle to maintain dynamic reactivity and flexibility on roads with complex geometries, leading to inefficiencies and difficulties in implementation.
Innovation Solution
A device comprising an observer module for generating a steering command based on actual measurements and an anticipator module that adds a curvature-dependent steering command, utilizing a combination of optical camera and radar data to calculate and adjust steering inputs dynamically, ensuring stable trajectory tracking even on roads with high curvature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a direct chain action module is used to produce steering commands based on target line position, then the system is simple to implement, but the vehicle cannot maintain dynamic reactivity on curves with strong curvature
Solution Approach 1:
The control system is divided into two independent modules: an observer module that generates stabilizing steering commands based on current trajectory deviations, and an anticipator module that generates curvature-based steering commands. This segmentation allows each module to specialize in one function, maintaining simplicity while improving overall performance on curved roads.
Solution Approach 2:
The anticipator module calculates the curvature of the road ahead and generates steering commands in advance based on the target curvature. By anticipating the upcoming curve and preparing steering commands beforehand, the system maintains dynamic reactivity and flexibility when negotiating curves with strong curvature.
2Adaptability or versatility
If the vehicle follows a target path with free-form curves, then the system can operate in unconstrained spaces, but it cannot adapt to traffic lane geometry constraints
Solution Approach 1:
The system changes the control parameter from following a pre-defined free-form curve to tracking the actual traffic lane geometry detected by sensors. The lane detection module continuously updates the target path based on real-world lane markings, allowing the vehicle to adapt to varying lane geometries while maintaining stable tracking through the observer module's stabilizing actions.
3Speed
If the system uses only current trajectory information for control, then the response is immediate, but the vehicle cannot anticipate upcoming curves
Solution Approach 1:
The anticipator module calculates the curvature of the road ahead at a distance in front of the vehicle and generates curvature-based steering commands in advance. This preliminary action allows the vehicle to prepare for upcoming curves, improving ride comfort and control stability while maintaining immediate response capability through the observer module.
Solution Approach 2:
The curvature calculation acts as an intermediary between the lane geometry and the steering control. By introducing curvature as an intermediate parameter that represents the road geometry ahead, the system can anticipate upcoming curves and generate appropriate steering commands before the vehicle reaches them, bridging the gap between immediate response and advance preparation.
Data Source
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AI summary
In order to allow a vehicle (1) to comfortably keep to a lane, in particular but not necessarily a lane comprising bends having high radii of curvature, the device for controlling the path of the vehicle (1) comprises an observation module (2) that generates, in real time from a current measurement vector (η), an estimated vector of the lane-keeping state (ζ) of the vehicle (1) moving at a current speed (va), so as to produce a first steering control (ust) in order to stabilise the path of the vehicle relative to the lane. The device further comprises an anticipation module (7) that adds, to the first steering control (ust), a second steering control (uff) that depends on a radius of curvature (ρff) to be applied to the path.