TOF Light Curtain Layout for Dynamic Robotic Area Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light curtain safety systems for industrial machinery are inadequate as they require multiple light curtains to define zones, fail to individually check LED operation, are prone to damage, and have inconsistent beam resolution, leading to potential false alarms and non-compliance with international safety standards.
Innovation Solution
A safety system utilizing Time-of-Flight (TOF) sensors positioned on vertical supports to create a light curtain that dynamically secures multiple areas with redundant sensors, ensuring consistent beam separation and minimizing false alarms by using laser light sources with collimated beams, and includes an integrity test to monitor sensor performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple light curtains are used to define various zones, then the coverage area increases, but the device complexity and cost increase
Solution Approach 1:
The patent combines multiple light curtain functions into a single integrated sensor unit that can define multiple zones (first zone, second zone, third zone) using one or more light curtains. This merging approach allows the system to cover various zones without requiring separate light curtain systems for each zone, thereby reducing device complexity while maintaining comprehensive area coverage.
2Ease of manufacture
If LEDs are positioned horizontally on the floor, then installation is simplified, but they become prone to damage and contamination
Solution Approach 1:
The patent transitions the sensor positioning from a horizontal floor-mounted arrangement to a vertical wall-mounted arrangement. This dimensional change elevates the sensors above the floor level, protecting them from damage and contamination while maintaining installation feasibility through standard wall mounting procedures.
3Area of stationary object
If beam spot size increases with distance, then the light curtain covers a larger area, but the resolution and detection capability decrease
Solution Approach 1:
The patent employs laser light sources instead of conventional LEDs, which fundamentally changes the beam characteristics. Laser beams maintain a consistent spot size and narrow width over distance, preserving detection resolution and measurement precision across the entire coverage area. This parameter change in light source technology allows the system to cover large areas without sacrificing the ability to detect small objects or precise intrusions.
4Area of stationary object
If the distance between light beams decreases with distance from LEDs, then the light curtain becomes more compact, but the detection resolution changes inconsistently
Solution Approach 1:
The patent changes the light source parameter from LED to laser, which produces beams with consistent spacing and uniform characteristics over distance. This parameter change ensures that the distance between adjacent light beams remains constant throughout the coverage area, providing stable and consistent detection resolution from near field to far field, and complying with international safety standards.
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 effectively secures industrial environments by maintaining consistent beam resolution and reducing false alarms, adhering to international safety standards while being more robust and cost-effective compared to traditional solutions.
Implementation Method 1
Each TOF sensor is adapted to measure a time of flight of a light beam emitted by the TOF sensor and reflected by an object
Implementation Method 2
The light curtain comprises laser light sources adapted to emit light beams
Implementation Method 3
each TOF sensor is adapted to measure a time of flight of a light beam emitted by the TOF sensor and reflected by an object
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Safety system (100) for an industrial environment (10) comprising a robotic machine wherein at least a moving head (12) of the robotic machine is movable within a first area (1) and a second area (2) of the industrial environment (10), the safety system (100) comprising: - a light curtain (110) extending between a first vertical support (112) and a second vertical support (114) to cover both the first area (1) and the second area (2); - a head position sensor (130) adapted to detect the position of the moving head (12) within the first area (1) and the second area (2); - a safety control unit (140); wherein the light curtain (110) comprises a first couple of two TOF sensors (F1, F3) respectively positioned on the first and second vertical supports (112, 114), the safety control unit (140) being adapted to process output signals received from the TOF sensors (F1, F3) and the head position sensor (130) so as to selectively and dynamically secure the first area (1) and the second area (2).