Protective Field Monitoring with In-Plane Distance Muting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing monitoring devices for danger zones, particularly those using light curtains, face issues with unreliable detection of permissible objects by muting sensors, complex signal coordination, and space-consuming setups, leading to unnecessary system shutdowns and errors.
Innovation Solution
The integration of distance sensors as muting sensors, oriented in the same plane as the protective field, allows for precise detection and partial or complete bridging of the safety sensor to prevent unnecessary shutdowns, with these sensors generating measured values simultaneously with the safety sensor, eliminating timing errors and optimizing space usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If light barrier arrangements are used as muting sensors, then the setup is simple, but permissible objects cannot be reliably detected
Solution Approach 1:
The patent replaces light barrier arrangements with distance sensors (such as ultrasonic, radar, or laser-based sensors) that actively measure distance to objects. This substitution enables reliable detection of permissible objects by providing precise distance measurements, allowing the system to distinguish between permissible objects (within expected distance ranges) and safety-critical intrusions, thereby resolving the reliability issue without significantly increasing complexity.
2Reliability
If muting sensors are installed upstream of the safety sensor, then permissible objects can be detected, but a considerable amount of space is required
Solution Approach 1:
The patent combines the muting sensor and safety sensor into a single integrated sensor unit. The distance sensors are arranged within the same housing as the safety sensor, allowing both functions (permissible object detection and safety monitoring) to be performed from the same location. This merging eliminates the need for separate upstream muting sensors, significantly reducing the space required while maintaining full detection capability.
Solution Approach 2:
The integrated sensor unit performs multiple functions: it acts as both a safety sensor for detecting intrusions and as a muting sensor for detecting permissible objects. The distance sensors measure distances to determine if objects are permissible (within expected ranges) or safety-critical (beyond expected ranges), allowing a single sensor arrangement to handle both safety monitoring and permissible object recognition tasks.
3Reliability
If muting sensors are positioned upstream of the safety sensor, then object detection is possible, but timing coordination becomes complex and error-prone
Solution Approach 1:
The patent merges the muting sensor and safety sensor into a single integrated unit with a common detection plane. Both the distance sensors and safety sensor measure objects at the same location and time, eliminating the need for complex timing coordination and signal synchronization between separate sensors. The control unit receives signals from both sensors simultaneously and processes them together, greatly simplifying the control logic and reducing errors.
Solution Approach 2:
The distance sensors continuously measure distances to objects in real-time, maintaining an ongoing record of object positions and characteristics. When an object enters the detection plane, the system has already accumulated preliminary data about the object's distance, speed, and trajectory, allowing for immediate and accurate determination of whether the object is permissible or safety-critical without requiring complex timing extrapolations.
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 solution enables reliable distinction between permissible and safety-critical objects, reducing errors and system downtime by precisely identifying permitted objects and allowing them to pass through the protective field without triggering the safety function, while maintaining a structurally simple and space-efficient design.
Implementation Method 1
The monitoring device typically uses a light curtain as a safety sensor to monitor a protective field lying in a plane
Implementation Method 2
The distance sensors detect an area that lies within the plane of the protective field
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a monitoring device (1) comprising an arrangement of muting sensors (11) and a safety sensor (6), which is designed to monitor a protective field extending in a plane such that a safety function is triggered when the safety sensor (6) detects an object intrusion within the protective field. When a permissible object is detected by the muting sensors (11), the safety sensor (6) is at least partially bypassed. The muting sensors (11) are formed by distance sensors arranged in the plane of the protective field. The distance sensors detect an area that lies within the plane of the protective field.