Multi-Optical Axis Sensor Control for Floating Blanking Safety
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Solution Overview
Problem
Existing multi-optical axis photoelectric sensors with floating blanking and monitoring fail to maintain safety when a manufacturing machine moves in and out of the detection area, leading to false stop signals and reduced production efficiency, as they cannot effectively differentiate between the machine and human presence, especially when the number of interrupted optical axes decreases below the preset threshold.
Innovation Solution
A multi-optical axis photoelectric sensor system that simultaneously activates floating blanking and blanking monitoring, allowing the system to maintain safety by differentiating between the machine and human presence through advanced signal processing and control mechanisms, ensuring that the manufacturing machine is not stopped unnecessarily when moving out of the detection area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If floating blanking is activated to allow machine movement within detection area, then productivity is improved, but safety reliability deteriorates when machine moves out of detection area
Solution Approach 1:
The detection area is segmented into multiple optical axes (e.g., 3-10 axes), and the system monitors the number of interrupted axes rather than individual axes. This segmentation allows the system to distinguish between machine presence (interrupting multiple axes) and human intrusion (interrupting fewer axes), resolving the contradiction between allowing machine movement and maintaining safety.
Solution Approach 2:
The system changes the parameter from binary detection (interrupted/not interrupted) to quantitative detection (number of interrupted axes). By setting a threshold value for the number of interrupted axes, the system can tolerate machine movement while still detecting human intrusion, thus improving productivity without compromising safety.
2Ease of operation
If floating blanking is used to permit machine movement, then ease of operation is improved, but measurement precision deteriorates in differentiating machine from human presence
Solution Approach 1:
The detection area is divided into multiple optical axes that collectively monitor the space. By counting how many axes are interrupted simultaneously, the system can differentiate between machine presence (affecting multiple adjacent axes) and human presence (affecting fewer axes), thereby maintaining measurement precision while improving ease of operation.
Solution Approach 2:
The system uses an excessive number of optical axes (more than the minimum needed) to create overlapping detection zones. This redundancy allows the system to accurately distinguish between different objects even when one object moves freely, as the probability of ambiguous detection is reduced.
3Reliability
If the system stops the machine whenever any optical axis is interrupted, then safety is improved, but productivity deteriorates due to false stop signals
Solution Approach 1:
The system changes from binary detection (stop on any interruption) to quantitative detection (stop only when interrupted axes exceed threshold). This parameter change allows the machine to operate continuously during normal machine movement while still stopping for human intrusion, thus improving productivity without compromising safety.
Solution Approach 2:
The system dynamically adjusts its response based on the number of interrupted axes. Instead of a static stop-on-any-interruption rule, the system adapts its behavior to the situation, allowing operation when interruptions are within expected ranges (machine movement) and stopping when interruptions exceed thresholds (potential human intrusion).
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 system maintains safety and production efficiency by preventing false stop signals when the manufacturing machine moves out of the detection area, while ensuring that human presence is detected and the machine is stopped when necessary, thus addressing the limitations of existing technologies.
Implementation Method 1
The emitter unit lights its emitter elements. As the emitter elements illuminate, the receiver unit obtains light receiving signals from their receiver elements corresponding to the illuminating emitter elements
Data Source
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AI summary
For a manufacturing machine that moves in and out of a detection area of a multi-optical axis photoelectric sensor, floating blanking and blanking monitoring are activated without outputting a stop signal to stop the manufacturing machine every when the manufacturing machine moves out of the detection area. A detection processing unit performs, when at least one of the plurality of optical axes is constantly interrupted by the object, floating blanking of outputting the detection signal upon determining that the number of optical axes in an interrupted state is greater than a preset maximum optical axis number, and blanking monitoring of outputting the detection signal upon determining that the number of optical axes in an interrupted state is smaller than a preset minimum optical axis number, and activates or deactivates the floating blanking and the blanking monitoring based on the signals received by the signal reception unit.