Adaptive Cruise Control With Jerk-Limited Deceleration
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Solution Overview
Problem
Existing adaptive cruise control systems in autonomous vehicles face a challenge in achieving a balance between dynamic and psychological comfort while ensuring safety during interactions with target vehicles, particularly when the target vehicle merges into the ego vehicle's lane, leading to excessive and abrupt decelerations.
Innovation Solution
A method and device that control the speed of an autonomous vehicle by determining a corrected potential acceleration using a jerk limit, based on instantaneous acceleration and a negative initial jerk, to regulate the vehicle's speed, minimizing abrupt decelerations and maintaining a controlled acceleration pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the ACC determines a high potential acceleration to quickly reduce inter-vehicle distance, then safety is improved by quickly establishing the predetermined distance, but dynamic comfort deteriorates due to strong deceleration
Solution Approach 1:
The patent applies parameter changes by modifying the acceleration profile through jerk limitation. Instead of applying full potential acceleration directly, the system adjusts the acceleration parameter over time using a jerk-constrained approach, where the rate of change of acceleration is limited. This transforms the abrupt high acceleration into a gradual acceleration profile that maintains safety while improving dynamic comfort.
Solution Approach 2:
The patent implements dynamics by introducing a time-varying acceleration profile rather than a static acceleration value. The jerk limitation creates a dynamic acceleration curve that evolves over time, starting from zero and gradually increasing toward the target acceleration. This dynamic approach allows the system to balance safety requirements with passenger comfort during the approach maneuver.
2Reliability
If the ACC applies strong deceleration to quickly approach the target vehicle, then the inter-vehicle distance quickly reaches the predetermined distance creating security, but psychological comfort deteriorates due to excessive deceleration being poorly perceived
Solution Approach 1:
The patent changes the deceleration parameter from a constant high value to a time-varying profile constrained by jerk limitations. The deceleration magnitude evolves gradually rather than applying instantaneously, which maintains the ultimate achievement of the predetermined distance while significantly improving psychological comfort by reducing the perceived harshness of the deceleration event.
3Ease of operation
If the ACC minimizes acceleration variations for dynamic comfort, then dynamic comfort is improved, but the time to reach the predetermined inter-vehicle distance increases
Solution Approach 1:
The patent uses a dynamic acceleration profile that gradually increases toward the target acceleration while being constrained by jerk limitations. This dynamic approach allows the system to start with smooth low acceleration for comfort, then progressively increase acceleration to reduce the total time to reach the predetermined distance, optimizing both comfort and time efficiency.
Solution Approach 2:
The patent maintains continuous acceleration action throughout the approach maneuver, with the acceleration magnitude smoothly varying over time rather than being interrupted or held constant. This continuous acceleration, constrained by jerk limitations, ensures the vehicle continuously closes the distance gap while maintaining comfort through smooth transitions.
Data Source
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AI summary
The invention relates to a method and a device for controlling the speed of an autonomous vehicle, which vehicle is referred to as an ego vehicle, approaching a target vehicle, the ego vehicle having adaptive cruise control, the method comprising the steps of: - acquiring (201) a potential acceleration; - acquiring (202) an instantaneous acceleration, at a given time t, of the ego vehicle; - determining (203) a jerk representing a change in acceleration, on the basis of the potential acceleration, on the instantaneous acceleration and a strictly negative predetermined initial jerk; - determining a corrected potential acceleration on the basis of the jerk, the jerk limiting the change in potential acceleration; - regulating the speed of the ego vehicle by the adaptive cruise control on the basis of the corrected potential acceleration.