Autonomous Emergency Braking Warning Phase Timing
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Solution Overview
Problem
Existing autonomous emergency braking systems often initiate the warning phase too early, leading to potentially unjustified driver behavior and increased risk, due to the lack of consideration for the partial braking effect during the haptic warning phase and varying reliability of distance measurement systems.
Innovation Solution
A method that takes into account the partial braking effect during the haptic warning phase, adjusting the timing of the warning phase initiation based on the reliability of the measurement system, and considers both longitudinal and lateral dynamic behaviors to ensure safer and more precise emergency braking operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the warning phase is initiated early to provide sufficient warning time to the driver, then the driver has more time to react, but the warning phase may be unjustified and cause risky driver behavior
Solution Approach 1:
The patent dynamically adjusts the timing of warning phase initiation based on measured vehicle deceleration parameters. By monitoring actual deceleration during the warning phase and comparing it to expected deceleration values, the system determines whether early initiation is justified by real braking effectiveness or should be delayed to avoid false alarms.
2Productivity
If the partial braking effect during haptic warning phase is considered in the dynamic criterion, then the timing of emergency braking initiation can be optimized, but the complexity of the control system increases
Solution Approach 1:
The patent combines the partial braking effect during the haptic warning phase with the main emergency braking calculation in a unified dynamic criterion. By merging these braking effects into a single comprehensive assessment model, the system optimizes emergency braking initiation timing without requiring separate complex control pathways.
3Ease of manufacture
If the warning phase is initiated based on fixed timing criteria, then the system is simple to implement, but it cannot adapt to varying measurement reliability and braking conditions
Solution Approach 1:
The patent transitions from fixed timing criteria to dynamic, adaptive timing based on real-time measurement of vehicle deceleration and assessment of distance measurement reliability. The system continuously adjusts the warning phase initiation timing according to actual braking effectiveness and sensor confidence levels, enabling adaptation to varying conditions while maintaining practical implementability.
Data Source
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AI summary
The invention relates to a method for determining autonomous emergency braking of an ego vehicle, comprising at least the following steps: capturing driving-dynamics variables of the ego vehicle and distance measurement signals and determining a longitudinal distance of the ego vehicle (1) from a front object (2), evaluating whether emergency braking should be initiated, and, if emergency braking should be initiated, determining a first starting point (t1) for the initiation of a warning phase (I), in which a warning signal is output without initiation of braking, a second starting point (t2) for the initiation of a subsequent partial-braking phase (II) with a lower partial-braking brake pressure (p_hc) and a third starting point (t3) for the initiation of a subsequent emergency-braking phase (III) with a higher emergency-braking brake pressure (p_aeb), wherein the following are used in the determination of the starting points (t1, t2, t3): a duration criterion having minimum durations of the warning phase (I) and/or of the partial-braking phase (II) and a dynamic criterion, which describes positions and/or velocities of the ego vehicle and of the object in the phases, wherein, in the dynamic criterion, motion equations of the ego vehicle and of the object in at least second order of time (t) are used and an emergency-braking acceleration in the emergency-braking phase (III) is used and at least in some situations a partial-braking acceleration in the partial-braking phase (II) is used in order to take into consideration a braking effect in the partial-braking phase (II).