Protective Field Muting via Timed Control Signal Matching
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Solution Overview
Problem
Existing monitoring devices for hazardous areas, particularly those using light curtains, face issues with unreliable detection of permissible objects, unnecessary machine standstill, space consumption by muting sensors, and complex signal coordination, leading to potential safety and operational inefficiencies.
Innovation Solution
A monitoring device that employs a safety sensor with a muting function triggered by external control signals, where the signal beginnings and ends are monitored within specific time windows to determine the activation and deactivation of the muting condition, eliminating the need for separate muting sensors and allowing for precise adaptation to operational conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If muting sensors are positioned upstream of the safety sensor to detect permissible objects, then the safety function can be bypassed for permissible objects, but the device complexity and space requirements increase
Solution Approach 1:
The patent extracts the muting function from separate upstream muting sensors and integrates it into the safety sensor itself. The safety sensor is designed to receive both safety-critical object detection signals and muting control signals, and internally determine whether to generate a switching signal based on the combination of these inputs. This eliminates the need for separate muting sensor devices positioned upstream.
Solution Approach 2:
The patent merges the functions of the safety sensor and muting sensors into a single integrated safety sensor device. The safety sensor simultaneously performs safety monitoring and permissible object detection, combining what were previously separate functional components into one unified device that reduces overall system complexity.
2Reliability
If muting sensors are positioned upstream of the safety sensor, then permissible objects can be detected, but a considerable amount of space is required
Solution Approach 1:
The patent removes the separate upstream muting sensor components that occupied additional space. Instead, the muting detection functionality is integrated into the safety sensor's signal processing unit, which evaluates control signals and determines muting conditions internally, eliminating the physical space requirements for separate muting sensor installations.
3Reliability
If separate muting sensors are used upstream of the safety sensor, then permissible objects can be detected, but the coordination and timing evaluation becomes complex and error-prone
Solution Approach 1:
The patent combines the signal evaluation and timing coordination functions into the safety sensor's integrated processing unit. The safety sensor receives control signals with timing information and internally coordinates the evaluation of these signals with the safety monitoring function, eliminating the complex external coordination required when separate muting sensors are used.
Solution Approach 2:
The patent implements a feedback mechanism where the safety sensor receives control signals containing timing information about permissible objects, evaluates whether the current time falls within the muting period based on this feedback, and adjusts its switching signal generation accordingly. This internal feedback loop simplifies the coordination complexity.
4Device complexity
If the safety sensor is muted based on external control signals without time window monitoring, then the structure is simpler, but the precision and security of the muting process is reduced
Solution Approach 1:
The patent implements dynamic time window monitoring where the safety sensor actively evaluates whether the current time falls within a predefined muting time window based on control signals. This dynamic temporal evaluation adds precision to the muting process while maintaining relatively simple device structure, as the time window logic is integrated into the sensor's processing unit.
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 enhances the monitoring device's functionality with a structurally simple design, reducing unnecessary shutdowns, improving detection reliability, and optimizing space usage while ensuring increased security and precision in managing the muting process.
Implementation Method 1
The monitoring device typically uses a light curtain as a safety sensor to monitor a protective field lying in a plane. The light curtain generates a switching signal, the states of which indicate whether an object is present in the protective field or not.
Implementation Method 2
A monitoring device acts as a muting condition, checking whether the start and/or end of the protection field violation signal and the active control signal fall within a predefined time window.
Data Source
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AI summary
The invention relates to a monitoring device (1) with a safety sensor (6) configured to monitor a protective field such that it generates a switching signal depending on object detections within the protective field. In the event of an object intrusion, a signal indicating a violation of the protective field is generated as the switching signal. An external unit generates a control signal with an inactive and an active signal state. The switching signal can be delayed by a predetermined time interval in a delay unit (19). A monitoring device serves as a muting condition to check whether the signal start and/or signal end of the protective field violation signal and the active control signal lie within a predetermined time window (Z1). The invention further relates to a corresponding method.