Vehicle Seat Pinch Detection Using Segmented Motor Current
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Solution Overview
Problem
Existing seat control devices struggle to accurately detect pinching of foreign matter between moving seats in vehicles, especially with flexible seats, leading to potential safety hazards and erroneous detection due to disturbances.
Innovation Solution
A moving body control device that includes a pinching detecting unit capable of calculating differences in motor current over various periods and determining pinching based on specific threshold conditions, distinguishing between pinching and disturbances to prevent erroneous detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a long period is used for calculating the difference value of motor current to ensure detection of pinching by flexible seats, then pinching detection accuracy is improved, but the possibility of erroneous detection due to disturbance increases
Solution Approach 1:
The patent divides the detection period into multiple sub-periods and calculates difference values for each sub-period separately. By segmenting the long detection period into shorter intervals, the system can identify pinching events more precisely while reducing the impact of disturbances that may occur within individual sub-periods. The control unit compares difference values across multiple sub-periods to confirm pinching, thereby improving detection accuracy while minimizing false positives.
Solution Approach 2:
The patent dynamically adjusts the detection strategy by evaluating difference values across multiple time points and sub-periods rather than using a fixed single-period threshold. The control unit determines pinching based on the pattern of difference values across several sub-periods, allowing the system to adapt to varying operating conditions and distinguish between actual pinching events and transient disturbances.
2Ease of operation
If the seat material is made flexible for comfort, then user comfort is improved, but pinching detection becomes delayed and less accurate
Solution Approach 1:
The patent segments the motor current signal into multiple measurement points within the detection period. By analyzing difference values at multiple sub-periods rather than relying on a single measurement, the system can detect the gradual load increase caused by pinching in flexible seats more accurately. This segmentation approach compensates for the cushioning effect of flexible materials that delays pinching detection.
Solution Approach 2:
The patent maintains continuous monitoring of motor current across multiple sub-periods within the detection period. By continuously evaluating difference values at multiple time points and requiring consistent patterns across sub-periods for pinching confirmation, the system ensures uninterrupted detection capability that overcomes the delayed response inherent in flexible seat materials.
3Measurement precision
If threshold value is set low for sensitive pinching detection, then pinching detection sensitivity is improved, but erroneous detection due to disturbance increases
Solution Approach 1:
The patent uses multiple sub-periods with individual difference value calculations instead of a single threshold comparison. By segmenting the detection process, the system can use lower sensitivity thresholds in each sub-period while requiring consistent pinching indicators across multiple segments, thereby maintaining high detection sensitivity without proportionally increasing false positive rates.
Solution Approach 2:
The control unit uses feedback from multiple difference value calculations across sub-periods to confirm pinching events. The system evaluates whether difference values in multiple sub-periods consistently indicate pinching before triggering an alarm, providing a feedback mechanism that filters out transient disturbances while maintaining sensitivity to genuine pinching events.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables reliable detection of pinching even with flexible seats, while minimizing erroneous detection due to disturbances, ensuring safety by accurately identifying and preventing pinching incidents.
Implementation Method 1
a motor current detecting unit that detects a motor current flowing through the motor
Data Source
AI summary
A moving body control device includes a pinching detecting unit. The pinching detecting unit is configured to calculate a first difference between physical quantities at a beginning and an end of a first period, calculate a plurality of second differences for respective second periods obtained by dividing the first period, each of the differences being a difference between physical quantities at a beginning and an end of the corresponding second period, and determine that pinching of an object has occurred in a case in which the first difference is equal to or greater than a first threshold value and a ratio of second differences equal to or greater than a second threshold value to the plurality of the second differences is equal to or greater than a third threshold value.