Actuator Sensor Frequency Switching for Reliable Door Control
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Solution Overview
Problem
Existing door and window drive systems face unreliable operating behavior due to potential internal errors or external disturbances that can simulate correct signals, leading to unsafe interactions with obstacles, and current solutions require additional hardware and software efforts for testing.
Innovation Solution
The system employs a sensor device that switches its output signal between two distinct frequencies when no object is detected and switches to a significantly different detection frequency upon object detection, eliminating the need for separate testing outputs and minimizing hardware and software expenditure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sensor device sends status messages to the control device for fault detection, then reliability is improved, but device complexity increases due to additional testing outputs and hardware requirements
Solution Approach 1:
The patent combines the status message transmission and test signal generation into a single communication channel. The sensor device uses its existing output signal to convey both operational status and test responses, eliminating the need for separate test outputs and reducing control device complexity while maintaining reliability
Solution Approach 2:
The output signal of the sensor device serves multiple functions: it transmits status messages about operational state and simultaneously responds to test signals from the control device. This multi-functionality reduces the need for dedicated testing hardware while maintaining fault detection capability
2Device complexity
If the sensor device uses a single frequency signal for object detection, then device complexity is minimized, but reliability deteriorates because external disturbances can simulate correct signals
Solution Approach 1:
The sensor device dynamically changes its output signal frequency based on operational mode. During normal operation, it uses a first frequency for object detection; when receiving a test signal, it switches to a second frequency for responding. This dynamic frequency adjustment prevents external disturbances at one frequency from simulating correct signals, thereby improving reliability without significantly increasing device complexity
Solution Approach 2:
The patent changes the frequency parameter of the sensor device's output signal depending on the operational state. By using different frequencies for different functions (object detection vs. test response), the system distinguishes between legitimate signals and external disturbances, improving signal accuracy while maintaining simple hardware
Data Source
Figure 1~2
AI summary
The actuator (1) has a drive device (2) driving a movable leaf (6), and a control device controlling the drive device based on an output signal of a sensor device (9) i.e. sensor strip, which delivers status messages to the control device. The signal is shifted between two signal frequencies in case of detection of an object at detection frequency. A switching frequency is predetermined for time points of shifting of the signal frequencies. The detection frequency is significantly deviated from the signal frequencies. The strip is formed at a region of an upper horizontal edge of the leaf. The object can be a person and/or an article.