Light Curtain Muting Control for Reliable Hazard Area Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing monitoring devices for danger areas, particularly those using light curtains, face issues with unreliable detection of permissible objects, complex timing coordination, and space-consuming muting sensors, leading to unnecessary system shutdowns and potential safety hazards.
Innovation Solution
A monitoring device with a safety sensor that operates with different detection configurations for protective field monitoring and interruption detection, allowing for partial or complete muting of the safety sensor to prevent unnecessary shutdowns, using a two-channel initiation of the muting operation and independent protective field monitoring detection to ensure fail-safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If muting sensors are arranged upstream of the safety sensor to detect permissible objects, then permissible objects can be identified to prevent unnecessary shutdowns, but the detection reliability of permissible objects is insufficient and the device occupies considerable space
Solution Approach 1:
The patent merges the safety sensor and muting sensor functions into a single light curtain device. The light curtain performs both safety monitoring and permissible object detection using the same optical components, eliminating the need for separate upstream muting sensors. This is achieved by evaluating different beam interruption patterns from the same light beam array to distinguish between safety-critical objects and permissible objects.
Solution Approach 2:
The light curtain is designed to perform multiple functions: safety monitoring, permissible object detection, and muting control. By using the same light beam infrastructure for both safety-critical and non-safety-critical object detection, the device achieves multi-functionality without requiring additional sensors or occupying extra space.
2Productivity
If muting sensors are arranged upstream of the safety sensor, then permissible objects can be detected, but the coordination of timing and signal evaluation becomes complex and error-prone
Solution Approach 1:
The patent combines the detection and evaluation functions into a single integrated system. The light curtain's evaluation unit directly processes beam interruption signals from the same light beams used for safety monitoring, eliminating the need for complex timing coordination between separate upstream muting sensors and the safety sensor. The system evaluates spatial patterns of beam interruptions to automatically distinguish permissible objects from safety-critical objects.
3Reliability
If the light curtain triggers the safety function when permissible objects move through the protective field, then safety monitoring is maintained, but unnecessary machine downtime occurs
Solution Approach 1:
The patent applies different evaluation criteria to different spatial regions and object types within the protective field. By analyzing the specific pattern of light beam interruptions (which beams are blocked, the spatial distribution, and temporal characteristics), the system locally adapts its response: triggering safety functions for safety-critical objects while allowing permissible objects to pass without shutdown.
Solution Approach 2:
The system changes the evaluation parameters based on the detected object type. For safety-critical objects, the light curtain uses strict safety monitoring parameters that trigger immediate shutdown. For permissible objects, the system switches to muting mode with different evaluation parameters that allow passage. This parameter switching is based on the spatial and temporal characteristics of the detected object.
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
The solution ensures reliable detection of safety-critical objects while allowing permissible objects to pass through without triggering the safety function, reducing unnecessary shutdowns and enhancing safety by using a two-channel initiation and independent protective field monitoring detection to prevent uncontrolled muting.
Implementation Method 1
the safety sensor is formed by a light curtain which generates a protective field in a monitoring plane
Implementation Method 2
Such muting sensors are typically formed by light barrier arrangements
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a monitoring device (1) with a safety sensor (6) for safeguarding a hazardous area at a system (2), wherein the safety sensor (6) is designed for object detection within a protective field. In monitoring mode, the safety sensor (6) performs protective field monitoring such that, upon object detection in at least one area of the protective field, it triggers a safety function for the system (2). The safety sensor (6) can be switched to muting mode by means of muting signals, whereby protective field interruption detection is performed in at least one area of the protective field. The protective field monitoring and protective field interruption detection are operated with different detection configurations. The safety sensor (6) is designed to perform protective field monitoring detection, in which it is checked whether the entire protective field is free of objects.The invention further relates to a corresponding method.