Optical Sensor Residual Protective Field for AGV False Alarm Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical sensors used in security technology for monitoring danger areas, such as on driverless transport systems, face challenges in defining a fixed protective field, which can lead to unnecessary triggering of safety measures due to environmental contours projecting into the field, especially when the vehicle is moving in curves.
Innovation Solution
The optical sensor generates a residual protective field based on detected permissible objects, allowing for speed-independent object monitoring, distinguishing between permitted and impermissible objects, and only triggering safety functions for impermissible objects, thus avoiding unnecessary downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed protective field is defined in the optical sensor, then the monitoring function can detect objects in the danger area, but environmental contours (e.g., walls, pillars) may project into the protective field and cause false object detection signals
Solution Approach 1:
The patent applies dynamics by making the protective field adaptive rather than fixed. The evaluation unit continuously adjusts the protective field boundary based on detected permissible objects and their contours. When a permissible object is detected, the protective field is dynamically modified to exclude the object's contour, preventing false alarms while maintaining reliable detection of actual dangers.
2Reliability
If the optical sensor triggers safety measures for any object penetration in the protective field, then safety is ensured, but unnecessary safety measures are triggered when permissible objects enter the field
Solution Approach 1:
The patent applies local quality by creating different evaluation zones within the protective field. The system distinguishes between regions where permissible objects may exist (excluded zones based on detected contours) and regions where any object penetration should trigger safety measures. This localized differentiation allows safety functions to activate reliably for actual dangers while ignoring permissible objects in their designated zones.
3Object-affected harmful factors
If environmental contours are excluded from the protective field to prevent false alarms, then false alarms are reduced, but the system requires complex object recognition and field adjustment mechanisms
Solution Approach 1:
The patent applies feedback by implementing a closed-loop system where the evaluation unit continuously monitors objects in the detection area, identifies permissible objects and their contours, and automatically adjusts the protective field boundary accordingly. This feedback mechanism enables the system to adapt to changing environments and object positions in real-time, reducing false alarms without requiring manual reconfiguration.
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 approach enables reliable and efficient detection of objects in danger areas, preventing false alarms and ensuring safe operation by adapting the monitoring zone to moving permissible objects, allowing for quick response times without additional speed sensors.
Implementation Method 1
at least one transmitter (3) emitting light beams (2)
Implementation Method 2
at least one receiver (4) receiving light beams (2)
Data Source
Figure 1a~1b
Figure 2~3a
Figure 3b~3c
AI summary
The invention relates to an optical sensor 1 for detecting objects 9 within a detection area, wherein a protective field 15, 15' is defined in the optical sensor 1, and wherein an object detection signal is generated in the optical sensor 1 when an object intrusion is detected within the protective field 15, 15'. Depending on the detection of a permissible object, a residual protective field 18 is generated within the protective field 15, 15' in the optical sensor 1. In the event of an object intrusion within the residual protective field 18, an object detection signal is generated in the optical sensor 1 only if this object intrusion represents a deviation from a permissible object structure. The invention further relates to a method for detecting objects 9 using an optical sensor. The optical sensor 1 is, for example, mounted on the front of a vehicle 14, such as an AGV (automated guided vehicle).For example, vehicle 14 moves towards a wall 16 until it is close enough that the wall 16 extends into the original protective field 15. A reflector 17, whose width corresponds approximately to the width B of the protective field 15, is attached to the surface of the wall 16, which constitutes a permissible object 16. The wall 16 is detected by the optical sensor 1 by sensing the contour of the reflector 17. The residual protective field 18 extends to the wall 16, and its length is L' < L.