Adaptive Cruise Braking Range Adjustment for Lateral Offset and Road Curvature
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Solution Overview
Problem
Conventional adaptive cruise-with-braking (ACB) systems fail to consider the lateral offset of a target vehicle and road curvature when determining the braking reaction distance, leading to inadequate safety and increased false positive alerts.
Innovation Solution
An ACB system that adjusts the braking reaction distance and following distance limit shape based on detected trigger events, including lateral offset and road curvature, using sensors and algorithms to determine the appropriate deceleration response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ACB systems use a single longitudinal threshold event to determine braking reaction, then the system is simple to implement, but the safety is inadequate and false positive alerts increase
Solution Approach 1:
The patent transitions from a single longitudinal dimension threshold to a two-dimensional evaluation system that incorporates both longitudinal distance and lateral offset. The follow distance limit shape defines a spatial region rather than a simple distance threshold, allowing the system to evaluate target vehicles based on their position in both longitudinal and lateral dimensions simultaneously.
Solution Approach 2:
The follow distance limit shape is dynamically adjusted based on host vehicle speed, curvature radius, and other operational parameters. The braking reaction distance varies dynamically rather than remaining fixed, allowing the system to adapt to different driving conditions and reduce false positives while maintaining safety.
2Speed
If ACB systems activate brakes based on any target vehicle within threshold distance, then response time is fast, but false positive alerts increase due to lateral offset and curve conditions
Solution Approach 1:
The system applies different evaluation criteria to different spatial regions. The follow distance limit shape creates zones with different braking thresholds - targets within the shape trigger braking while those outside do not, even if at similar longitudinal distances. This local differentiation reduces false positives from vehicles in adjacent lanes or on curves.
Solution Approach 2:
The system continuously monitors target vehicle position relative to the follow distance limit shape and adjusts braking decisions based on this feedback. The dynamic recalculation of the shape based on host vehicle speed and road curvature provides ongoing feedback that prevents false positive alerts while maintaining rapid response to genuine threats.
3Adaptability or versatility
If braking reaction distance is fixed, then the system is easy to control, but it cannot optimize for different road conditions and vehicle speeds
Solution Approach 1:
The system changes key parameters including braking reaction distance, follow distance limit shape, and threshold values based on host vehicle speed, road curvature radius, and other operational conditions. These parameter adjustments allow the system to adapt to varying driving conditions while maintaining a unified control structure that preserves ease of operation.
Solution Approach 2:
The follow distance limit shape serves multiple functions simultaneously - it defines the braking trigger zone, accounts for lateral offset, adjusts for curve conditions, and adapts to different speeds. This multi-functional approach provides condition adaptability without requiring separate control systems for different scenarios.
Data Source
AI summary
When employing an adaptive cruise-with-braking (ACB) system to control host vehicle braking reaction distance, a plurality of trigger conditions (e.g., environmental parameters) are monitored. If one or more of the monitored parameters exceeds a predefined threshold, a trigger event is detected, and at least one of a braking reaction distance (BRD) and a following distance limit shape (FDLS) are adjusted. The BRD and FDLS adjustments may be predefined according to the type and/or magnitude of the trigger event. Trigger events may be weighted or prioritized such that higher priority trigger event types correspond to larger BRD reductions, etc. Monitored trigger conditions may include adverse weather, dangerous road terrain or topography, high traffic density, erratic forward vehicle behavior, and the like.