Pinching Detection in Vehicle Door Control Device
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Solution Overview
Problem
Existing systems for detecting pinching in vehicle back doors, especially when the door is bent due to pinching, suffer from delayed detection, as the current difference value changes slowly due to the reduced torque and motor current, leading to longer times to detect pinching.
Innovation Solution
The proposed solution involves a control unit that calculates a current difference value and its differential, adding them together with a coefficient, and comparing the result to a threshold to quickly detect pinching, allowing for earlier detection than conventional methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the back door is bent due to pinching force, then the pinching detection becomes delayed because the current difference value changes slowly, but the detection sensitivity must be maintained to identify pinching conditions
Solution Approach 1:
The patent applies dynamics by introducing a moving threshold that adapts to the current difference value over time. Instead of using a fixed threshold, the threshold dynamically adjusts based on the operational state of the door, allowing for earlier detection when the door is bent while maintaining accuracy during normal operation. This resolves the contradiction by enabling timely detection without sacrificing accuracy.
Solution Approach 2:
The patent changes the detection parameter from a static current difference threshold to a dynamic threshold that varies with operational conditions. By modifying the threshold parameter based on real-time current difference values and operational state, the system achieves both early detection and maintained accuracy even when the door bends during pinching events.
2Device complexity
If a fixed threshold is used for pinching detection, then the detection method is simple, but the detection time increases when the door is bent due to slow current change
Solution Approach 1:
The patent transforms the static detection algorithm into a dynamic one where the threshold automatically adjusts based on operational conditions. This adds complexity to the algorithm but enables much faster detection by adapting the threshold to match the current operational state, thereby resolving the time loss issue without requiring overly complex hardware modifications.
Solution Approach 2:
The patent implements feedback by continuously monitoring the current difference value and using it to adjust the detection threshold in real-time. This feedback mechanism allows the system to learn from the operational state and adjust its detection parameters accordingly, achieving faster detection while maintaining reasonable algorithmic complexity through intelligent control rather than hardware complexity.
3Stability of the object's composition
If the motor current changes slowly when the door is bent, then the mechanical system is stable, but the pinching detection becomes delayed
Solution Approach 1:
The patent applies dynamics by creating a dynamic threshold that responds to the operational state of the door. When the door is bent and current changes slowly, the threshold automatically adjusts to account for this reduced current variation, enabling timely detection without disrupting the natural stability of the mechanical system. This resolves the contradiction by adapting the detection system to the stable but slowed mechanical response.
Solution Approach 2:
The patent changes the detection parameter from a fixed current threshold to a dynamic threshold that adapts to the rate of current change. This parameter modification allows the system to maintain stable operation during normal conditions while achieving faster detection when the door bends, by adjusting the threshold to match the actual operational characteristics rather than assuming a fixed response pattern.
Data Source
AI summary
An opening/closing body control device is provided that can quickly detect pinching even when the opening/closing body is bent due to the pinching.An opening/closing body control device includes a motor drive unit that drives a motor for opening and closing the opening/closing body, and a control unit that controls an operation of the motor drive unit. The opening/closing control device includes a difference value calculator that calculates a current difference value that is a difference between a present value and a past value of a motor current, a differential value calculator that calculates a differential value of the current difference value, an adder that adds the current difference value and the differential value, and a pinching detection unit that judges whether or not pinching occurs at the opening/closing body based on a comparison result between the added value and a threshold.