Dual-Scanner Access Monitoring for Variable Roll Winder Openings
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Solution Overview
Problem
Existing security monitoring systems for roll unwinders and rewinders in printing presses face challenges in adapting to varying roll sizes and shapes, particularly large and stepped rolls, which complicates effective access control and safety monitoring.
Innovation Solution
A monitoring sensor system comprising two scanners that scan overlapping or adjoining protective fields of different sizes and shapes, allowing for simultaneous evaluation of protective field violations across multiple sub-areas, enabling adaptable access control for rolls ranging from 200 mm to 1800 mm in diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single scanner is used to monitor access to the safety area, then the device complexity is low, but the measurement precision and reliability of detecting objects of different sizes and shapes is insufficient
Solution Approach 1:
The monitoring task is segmented into multiple scanning zones (first scanning zone and second scanning zone) that are assigned to different scanners. Each scanner monitors a specific angular range within the opening, allowing for more precise detection of objects at different positions and orientations while maintaining manageable system complexity through divided responsibilities.
Solution Approach 2:
The system transitions from a single-point or single-line detection approach to a multi-dimensional scanning approach by introducing multiple scanners that cover different angular ranges. This creates a comprehensive three-dimensional monitoring volume that improves detection accuracy for objects of varying sizes and shapes without proportionally increasing system complexity.
2Adaptability or versatility
If the number of sensors is increased to cover all roll sizes from 200 mm to 1800 mm, then the adaptability improves, but the device complexity and cost increase
Solution Approach 1:
Each scanner is designed to perform multiple functions by monitoring different angular ranges that collectively cover the entire opening. The scanners can detect various object types (rolls of different diameters, stepped rolls, personnel) depending on their position, allowing a limited number of sensors to achieve universal monitoring capability across the full roll size spectrum from 200 mm to 1800 mm.
Solution Approach 2:
The system uses dynamic evaluation of scan images to adapt to different roll sizes and shapes. The evaluation device analyzes the patterns of protective field violations in real-time, automatically adjusting the interpretation of detected objects based on the violation patterns, which allows the fixed sensor configuration to handle variable roll dimensions without requiring additional sensors.
3Reliability
If multiple scanners with overlapping fields are used, then the reliability of simultaneous protective field violation detection improves, but the device complexity increases
Solution Approach 1:
The evaluation device continuously monitors the scan images from multiple scanners and provides feedback on protective field violations. By analyzing the patterns of violations across different scanners and comparing them against expected patterns for permitted objects versus safety violations, the system achieves high detection reliability. The feedback mechanism allows the system to distinguish between legitimate roll passages and actual safety threats without requiring excessive sensors.
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 allows for simple adaptation to different roll sizes and shapes without increasing the number of sensors, ensuring effective access control and safety monitoring across a wide range of roll diameters, including large and stepped rolls, thereby enhancing operational safety and efficiency in packaging and industrial printing processes.
Implementation Method 1
Two scanners (21) included in the monitoring sensor system scan an angular range each, lying in a same plane running in the opening, with their respective measuring beams
Data Source
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AI summary
The invention relates to a method for monitoring an access point (11; 12) which leads into a safety region (08; 09) of a roll winder or unwinder and through which rolls (16; 17) can be transported in and/or out along a transport path, the access point (11; 12) being formed by an opening provided between two elements mechanically delimiting the safety region (08; 09), and the access point (11; 12) being monitored by monitoring sensors of a monitoring system, wherein: two scanners (21) included in the monitoring sensors each scan, with their respective measuring beams, an angle region lying in the same plane (E) extending within the opening; the access point (11; 12) is monitored in a pattern of protection fields M(Fj) having multiple protection fields (Fj) of differing size and/or shape; for several of the protection fields (Fj) of differing size and/or shape, the scanned images of the two scanners (21) are checked for violation of the relevant protection fields (Fj) of differing size and/or shape in differing, adjoining or overlapping portions (E1; E2) of the plane (E); and information about the reliability of an identified protection field violation is derived via an evaluation of the violation patterns of violated protection fields (Fj) obtained in the two portions.