Motor Controller Correction Unit for Entrapment Detection
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Solution Overview
Problem
Existing opening/closing member driving devices, such as power window systems, face issues with erroneous determination of entrapment or catching due to changes in motor rotation speed when reversing direction in high-load ranges, leading to potential misidentification of foreign objects.
Innovation Solution
Incorporating a correction unit within the controller that adjusts the masking period or threshold values based on the direction of motor operation and load conditions, specifically extending the masking period when reversing in high-load ranges to prevent false entrapment or catching alarms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the masking period is extended to account for slack in looped wire during reverse operation in high-load range, then erroneous determination is reduced, but the system becomes more complex
Solution Approach 1:
The correction unit performs preliminary adjustment of the masking period before the abnormality determination process occurs. By detecting the operational state (high-load range and reverse activation) in advance, the system pre-adjusts the masking period to appropriate values, preventing erroneous determination before it happens rather than reacting after the fact.
2Reliability
If the threshold value is adjusted to prevent false alarms during high-load reverse operation, then false determination is reduced, but detection sensitivity decreases
Solution Approach 1:
The threshold value adjustment is applied locally and selectively rather than globally. The correction unit modifies the threshold only for specific operational conditions (when the opening/closing member is in high-load range and the motor activates in the opposite direction to preceding operation). For all other operational states, the normal threshold values remain in effect, preserving detection sensitivity where needed.
Data Source
AI summary
An opening/closing member driving device includes a motor that opens and closes an opening/closing member and a controller configured to perform an abnormality determination process and a masking process. The abnormality determination process determines occurrence of a foreign object being entrapped or caught by comparing driving information corresponding to a driving status of the motor to a predetermined threshold value. The masking process invalidates the abnormality determination process over a predetermined masking period when the motor is activated. The controller includes a correction unit. The correction unit corrects at least one of the masking period or the threshold value when the motor is activated in a direction opposite to that of a preceding operation in a state in which the opening/closing member is in a high-load range.