Imaging Sensor Safety Monitoring with Projected Pattern Self-Test
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Solution Overview
Problem
Existing imaging sensors used in safety-critical applications are not sufficiently fail-safe, making it difficult and costly to implement them in safety functions, as they require complex safeguarding and fail-safe designs to meet safety standards.
Innovation Solution
A test device is used to check the functionality of imaging sensor units, allowing for the use of standard components without individual fail-safe designs, with a safety controller ensuring fail-safe execution of safety reactions, and a pattern projection system to verify sensor functionality, enabling a cost-effective and flexible safety function implementation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If standard imaging sensors are used for safety functions, then cost and complexity are reduced, but reliability and safety are insufficient
Solution Approach 1:
A test device is introduced as an intermediary between the standard imaging sensor and the safety function. The test device includes a projection unit that projects test patterns and a processing unit that evaluates sensor responses, thereby mediating the reliability gap between standard sensors and safety requirements
Solution Approach 2:
The test device creates virtual test objects by projecting patterns into the monitoring area, allowing the sensor to be tested without requiring physical test objects. This copying approach enables comprehensive safety verification using standard sensors
2Reliability
If complex safeguarding is implemented in imaging sensors, then reliability is improved, but device complexity and cost increase
Solution Approach 1:
The safety function is segmented into two independent parts: the standard imaging sensor and the test device. The sensor remains simple while the test device handles all safety-related complexity, allowing standard components to be used without compromising safety
Solution Approach 2:
The test device serves as an intermediary that absorbs all safety-related complexity, allowing the imaging sensor itself to remain simple and standard while still enabling safe operation through the additional testing layer
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 allows for the implementation of a cost-effective and fail-safe system using imaging sensors, ensuring functional safety without the need for complex safeguarding of individual components, and concentrating safety-related devices in the controller, thus simplifying and reducing the cost of safety function execution.
Implementation Method 1
a projection unit (20) which is set up to project a pattern (28) with defined properties into a work area (24)
Implementation Method 2
an imaging sensor unit (12) which is set up to image a monitoring area (24) of a technical installation
Data Source
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AI summary
Device (10) and method for performing a safety function, in particular for monitoring a safety area of a technical system. The device (10) comprises an imaging sensor unit (12) for detecting an event triggering the safety function within a defined working area (24), a controller (14) for executing a safety-related response depending on the triggering event, and a test device (16) for verifying the functionality of the imaging sensor unit (12), which includes a processing unit (18) and a projection unit (20). The projection unit (20) is configured to project a pattern (28) with defined properties into the working area (24), and the processing unit (18) is configured to evaluate the image data acquired by the imaging sensor unit (12), to detect the projected pattern (28), and to extract its specific properties.Furthermore, the processing unit (18) is designed to compare the specific properties of the captured projected pattern with the defined properties.