Adaptive Speed Control for Autonomous Vehicles
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Solution Overview
Problem
Current autonomous vehicle systems are limited by the range of their forward-facing sensors, which restricts their maximum speed due to the need to avoid stationary objects, and sudden braking poses a risk of rear-end collisions.
Innovation Solution
An adaptive speed control system that uses a forward-facing sensor and electronic processor to determine a velocity setpoint based on sensor range and adjust it according to the speed of preceding vehicles, allowing for increased speed when the preceding vehicle is traveling faster, while ensuring safe deceleration capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the maximum speed is limited by sensor range to ensure safe stopping distance, then collision avoidance is improved, but vehicle speed and productivity deteriorate
Solution Approach 1:
The system dynamically adjusts the velocity setpoint limit based on real-time detection of preceding vehicles. When a preceding vehicle is detected within the sensor range, the system raises the speed limit from the conservative sensor-range-based limit to a higher value that maintains safe stopping distance while enabling faster travel. This dynamic adjustment resolves the contradiction by making the speed limit adaptive rather than static.
Solution Approach 2:
The system uses feedback from the sensor detection of preceding vehicles to adjust the velocity setpoint limit. The electronic processor continuously monitors whether a preceding vehicle is within range and adjusts the speed limit accordingly - raising it when safe to do so and maintaining the lower limit when safety requires. This feedback mechanism allows the system to optimize speed while maintaining collision avoidance capability.
2Speed
If sudden full-braking is used to stop for stationary vehicles, then stopping distance is reduced, but rear-end collision risk increases
Solution Approach 1:
The system performs preliminary action by continuously determining and adjusting the velocity setpoint limit based on sensor range and preceding vehicle detection. By proactively setting appropriate speed limits before reaching stationary objects or slow-moving vehicles, the system ensures the autonomous vehicle can decelerate smoothly at approximately 3m/s² rather than requiring sudden full-braking, thus avoiding rear-end collisions while maintaining adequate stopping distance.
Data Source
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AI summary
A method and system for operating an autonomous vehicle. The method includes determining, at an electronic processor, a limit for a forward velocity setpoint of the autonomous vehicle based a range of a forward facing sensor and detecting whether a preceding vehicle is in a field of view of the forward facing sensor. The method includes determining a speed of the preceding vehicle, and when the preceding vehicle is in the field of view of the autonomous vehicle, adjusting the limit based on the speed of the preceding vehicle.