Safety Area Monitoring with Temporally Coded Light Patterns
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Solution Overview
Problem
Existing safety area monitoring systems in factory environments face challenges in reliably detecting violations, especially under sudden disturbing influences like changes in surrounding light, which can lead to false negatives or incorrect detection of intrusions.
Innovation Solution
A system that projects a temporally coded sequence of lines or patterns into the working space, allowing for the evaluation of multiple consecutive images to differentiate between actual violations and transient disturbances, using an illumination device and evaluation device to compare recorded images with an expected sequence and output a violation signal only when discrepancies are confirmed across multiple frames.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a simple alternating projection (on/off or single intensity change) is used, then the device complexity is low, but the reliability of violation detection deteriorates under sudden disturbing influences like light changes
Solution Approach 1:
The patent applies periodic action by projecting a temporally coded sequence of lines or patterns that repeats over time. Instead of simple alternating on/off projection, the system projects a structured sequence with specific temporal coding that allows differentiation between actual violations and transient disturbances. This periodic structured projection enhances detection reliability while maintaining manageable system complexity through systematic pattern repetition.
Solution Approach 2:
The patent implements parameter changes by varying multiple parameters of the projected light sequence including temporal positioning, intensity levels, and spatial patterns. The evaluation device compares recorded images against an expected sequence with specific temporal and spatial parameters. When disturbances occur, the system can distinguish them from actual violations by detecting parameter deviations in the temporal coding structure, thereby improving reliability without requiring overly complex hardware.
2Measurement precision
If only two consecutive images are evaluated, then the processing speed is high, but the measurement precision of violation detection deteriorates due to false positives from transient disturbances
Solution Approach 1:
The system uses periodic structured projection sequences where multiple consecutive images are captured according to a predetermined temporal pattern. By evaluating multiple images within this periodic framework rather than just two, the system achieves higher measurement precision in distinguishing actual violations from transient disturbances. The temporal coding in the periodic sequence provides additional discrimination capability that justifies the increased evaluation time.
Solution Approach 2:
The evaluation device implements feedback by comparing recorded images against an expected sequence and using the results to determine whether a violation occurred. The system processes multiple consecutive images with temporal coding information, providing feedback that enhances detection precision. This multi-image feedback mechanism reduces false positives caused by transient disturbances while maintaining efficient processing through systematic comparison against the expected temporal pattern.
3Measurement precision
If a temporally coded sequence is projected and multiple images are compared, then the detection precision is improved, but the device complexity increases
Solution Approach 1:
The patent applies parameter changes by encoding temporal information into the projection sequence through systematic variations in timing, intensity, and spatial positioning. The evaluation device extracts projection beams with high precision by comparing multiple images against an expected sequence with defined temporal and spatial parameters. This parameter-based approach achieves high extraction precision while keeping device complexity manageable through structured, rule-based comparison rather than requiring complex algorithms or additional hardware components.
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
This approach provides unambiguous and robust detection of safety area violations, reducing the risk of false alarms and ensuring reliable extraction of projection beams even under adverse conditions, thus enhancing working safety by accurately identifying intrusions into the safety area.
Implementation Method 1
The illumination device is configured to project lines or patterns which define the safety area, into the working space
Implementation Method 2
The recording device is configured to record images in a monitoring area which encompasses the safety area
Data Source
AI summary
The application relates to an appliance (1) for creating and monitoring a safety area (2) in a working space (3). The suggested appliance (1) comprises a recording device (4). The recording device (4) is configured to record images in a monitoring area (8) which encompasses the safety area (2). The appliance (1) further comprises an illumination device (5) which is configured to project lines or patterns which define the safety area (2), into the working space (3). Furthermore, the appliance (1) comprises an evaluation device (9) which is configured to evaluate the images which are recorded by the recording device (4), with respect to a violation of the safety area (2). The illumination device (5) is configured to project a temporally coded sequence (11, 11′, 11″, 11′″, 11′″″) of the lines (6) or patterns into the working space (3). Furthermore, the evaluation device (9) is configured to compare images of the temporally coded sequence (11, 11′, 11″, 11′″, 11′″″) of the lines (6) or patterns with the expected sequence and to output a violation signal if the images of the temporally coded sequence (11, 11′, 11″, 11′″, 11′″″) do not correspond to the expected sequence.