Vehicle Control Apparatus for Autonomous Lane Keeping on Curved Roads
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Solution Overview
Problem
Existing vehicle control systems face challenges in ensuring autonomous travel on curved roads when there is an error in the estimated longitudinal position of the vehicle, leading to potential deviations from the traveling lane.
Innovation Solution
A vehicle control apparatus that includes a longitudinal position collation unit, estimation unit, error estimation unit, radius acquisition unit, curve travel speed calculation unit, speed control unit, and request unit to adjust vehicle speed and control mode based on estimated errors and curve radii, ensuring the vehicle stays within the lane by decelerating or switching to manual control when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the vehicle speed is maintained at high speed when entering a curved road, then the productivity is improved, but the vehicle cannot autonomously travel within the traveling lane due to position estimation error
Solution Approach 1:
The vehicle control apparatus dynamically adjusts the vehicle speed based on the detected curve radius and position estimation error. The speed is not fixed but varies according to road conditions and system accuracy, allowing the vehicle to maintain high speed on safe curves while reducing speed on curves with larger position errors, thus resolving the contradiction between productivity and reliability
Solution Approach 2:
The system changes the speed parameter adaptively based on multiple factors including curve radius, position estimation error, and road geometry. By continuously adjusting this critical parameter according to real-time conditions, the system optimizes both travel efficiency and lane-keeping reliability
2Reliability
If the curve travel speed is reduced to accommodate large position estimation errors, then the autonomous travel reliability is improved, but the productivity decreases
Solution Approach 1:
Rather than uniformly reducing speed for all curved roads, the system dynamically determines speed based on the specific position estimation error for each curve. When position error is small, high speed is maintained; when error is large, speed is reduced only for that specific curve, optimizing the balance between reliability and productivity across different scenarios
Solution Approach 2:
The speed adjustment is applied locally to specific curves with large position estimation errors rather than globally to all curved roads. This localized approach ensures that only the necessary portions of the journey experience speed reduction, minimizing the impact on overall productivity while maintaining reliability where needed
3Stability of the object's composition
If the vehicle decelerates to curve travel speed when curve travel speed is below reference speed, then the autonomous travel stability is improved, but the hands-on request timing becomes critical
Solution Approach 1:
The system performs preliminary actions by notifying the driver in advance before the vehicle decelerates to a speed requiring manual intervention. This advance notification gives the driver time to prepare for takeover, improving ease of operation while maintaining the stability benefits of controlled deceleration
Solution Approach 2:
The system provides feedback to the driver through notifications when speed adjustments will result in speeds below the reference speed, requiring manual intervention. This feedback loop allows the driver to be aware of upcoming changes and prepare appropriately, balancing automated stability control with manual operation readiness
Data Source
AI summary
To control a speed at a time of entering a curved road a vehicle to autonomously travel within a travelling lane even in a case where there is an error in an estimated longitudinal position of the vehicle.A curve travel speed calculation unit 15b calculates a curve travel speed for a vehicle to autonomously travelling in a travelling lane based on a curve radius and an estimated error in longitudinal position. A speed planning unit 15c and a travel control unit 17 decelerate the vehicle M such that the speed of the vehicle M becomes the curve travel speed at the time of entering the curved road in front of the vehicle M in a case where the speed of the vehicle M is equal to or higher than the curve travel speed and the curve travel speed is equal to or higher than the reference speed.