Optical Sensor Fault Detection via Synchronous Signal Sampling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical sensors face challenges in uncontrolled reduction of switching frequency due to fault detection methods, inability to detect interference radiation during transmission pulses, and limited applicability to sensors with varying pulse/pause ratios, leading to potential malfunctions and false detections.
Innovation Solution
A method that synchronously samples received signals with the transmission clock frequency, generates object detection signals by scanning sampled values, and differentiates between various types of interference, allowing for detection and adaptation to disturbances, including changing the clock frequency to avoid interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fault detection is implemented by delaying transmission pulse emission, then interference detection capability is improved, but switching frequency is reduced in an uncontrolled manner
Solution Approach 1:
The patent performs preliminary sampling of the received signal during the transmission pause period before the next transmission pulse is emitted. This preliminary action allows the system to detect interference and make informed decisions about pulse emission timing, thereby preventing uncontrolled reduction of switching frequency while maintaining reliable fault detection capability.
2Productivity
If transmission pulses are emitted continuously, then switching frequency is maintained, but interference radiation during transmission cannot be detected
Solution Approach 1:
The patent segments the transmission cycle into distinct phases: transmission pulse emission period and transmission pause period. During the pause period, the system performs interference detection by sampling the received signal. This segmentation allows continuous operation at high switching frequency while providing dedicated time for interference detection, resolving the contradiction between productivity and reliability.
3Device complexity
If pause duration is made considerably longer than pulse length, then interference detection is simplified, but adaptability to various pulse/pause ratios is reduced
Solution Approach 1:
The patent implements a dynamic sampling approach where the sampling timing and duration are adjusted based on the actual pulse/pause ratio of the transmission signal. The evaluation unit adapts the sampling strategy to match the specific characteristics of each transmission cycle, enabling the system to handle various pulse/pause ratios effectively while maintaining relatively simple interference detection methodology.
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
Enables accurate fault detection and differentiation, effective interference detection during transmission pulses, and adaptability to various pulse/pause ratios, reducing false detections and ensuring the optical sensor operates in a safe state.
Implementation Method 1
a receiver (5) receiving received light beams (4)
Implementation Method 2
a transmitter (3) emitting transmitted light beams (2)
Data Source
Figure 1~2
Figure 3a~5b
Figure 6a~7
AI summary
The method involves emitting transmission light radiation in the form of transmission pulses with a determined duty cycle by a transmitter (3). A receiving signal provided by a receiver (5) is sampled synchronously at a transmit clocking of the transmitter. An average value of the sampled receiving signal is constant during a failure-free operation of an optical sensor, and deviations from the constant average value are evaluated for determining the failure of the optical sensor, where a threshold evaluation is executed for determining the status of the failure.