Vehicle Collision Protection Device Dynamic Speed Estimation
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Solution Overview
Problem
Conventional collision injury/damage reduction apparatuses face inaccuracies in determining when to activate protection devices due to reliance on pre-collision relative speed thresholds, which do not account for changes in relative speed after the second threshold time, leading to potential erroneous actuations.
Innovation Solution
The apparatus calculates a collision speed based on vehicle deceleration caused by automatic braking and estimates it using formulas that account for changing relative speeds, ensuring accurate determination of protection device activation conditions at the time of potential collision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a threshold-based determination is made by comparing relative speed before collision with threshold speed, then the determination process is simple, but the accuracy of determining whether protection devices should be actuated becomes low
Solution Approach 1:
The patent applies dynamics by transitioning from a static threshold comparison (using fixed pre-collision speed) to a dynamic assessment that accounts for changing relative speed during the collision process. The system now considers the relative speed at the moment of collision rather than relying solely on pre-collision measurements, making the determination adaptive to the actual collision conditions.
Solution Approach 2:
The patent changes the parameter used for determination from pre-collision relative speed to collision-relative speed. By modifying which parameter is considered (from speed before braking intervention to speed at actual collision moment), the system achieves more accurate determination of whether protection devices should be actuated.
2Reliability
If automatic braking system decelerates the vehicle to reduce collision speed, then safety is improved, but the relative speed changes after second threshold time making pre-set threshold determination inaccurate
Solution Approach 1:
The patent implements feedback by continuously monitoring the relative speed during the collision process and using this real-time information to determine whether protection devices should be actuated. The system feeds back the actual collision relative speed to the determination logic, allowing accurate assessment despite the dynamic changes caused by automatic braking intervention.
Solution Approach 2:
The patent performs preliminary action by calculating the predicted collision relative speed before the actual collision occurs. This allows the system to prepare the determination of protection device actuation in advance, considering the expected collision conditions rather than relying on outdated pre-collision measurements.
Data Source
AI summary
An on-vehicle apparatus is provided to reduce damage from collisions. In the apparatus, an object located in a field in a travel direction of a vehicle is detected and a time to collision (TTC) is detected. A controller performs automatic intervention braking in the vehicle when it determined that the time to collision is equal to or shorter than a first threshold time. Further, when it determined that the time to collision is equal to or shorter than a second threshold time shorter than the first threshold time and meets a preset actuation condition, a protection controller makes a protection device active for vehicle protection. A collision speed is also estimated based on an deceleration of the vehicle caused by the automatic intervention braking. The preset actuation condition is a condition that the estimated collision speed is equal to or higher than a preset threshold speeds.