Sensor Switching Point Detection Using Value Comparison and Timing

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Solution Overview

Problem

Existing sensor systems require complex frequency evaluations and significant data processing to define switching points, making the process cumbersome and inefficient for determining the position of measurement objects, such as pistons, in automation systems.

Innovation Solution

A sensor system with an evaluation device that uses a comparison device and timer to compare current measured values with stored values, continuing a time measurement process if a predefinable criterion is met, and emitting a trigger signal when a predetermined time is reached, allowing for the automated definition of switching points with minimal data processing effort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If frequency evaluation and data storage methods are used to define switching points, then measurement accuracy is improved, but device complexity and data processing effort increase significantly

Engineering Contradiction:
Improveswitching point detection accuracyVSAvoiddata processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential information needed for switching point detection - specifically comparing current measured values with previously stored values to identify when the measurement object remains stationary. This selective extraction eliminates the need for complex frequency evaluations and extensive data storage, reducing processing complexity while maintaining detection accuracy

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of analyzing frequency distributions of measured values to find switching points, the patent inverts the approach by monitoring when measured values remain unchanged over a predetermined time period. This temporal stability detection replaces complex statistical analysis with simple comparison operations, significantly reducing computational requirements

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If extensive data storage and frequency evaluation are performed, then switching point detection reliability is improved, but processing time and operational complexity increase

Engineering Contradiction:
Improveswitching point detection reliabilityVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent stores a previous measured value in advance and continuously compares current values against this stored reference. This preliminary preparation of comparison data enables immediate detection of stationary conditions without waiting for complex frequency analyses, reducing processing time while maintaining reliable detection

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs periodic sampling of measured values and compares each new sample against the stored previous value. This periodic measurement approach, combined with a predetermined time threshold, reliably identifies stationary positions by detecting when values remain unchanged over multiple periods, achieving reliable detection with minimal processing delay

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3008426B1Sensor system and method for automatically determining a switching point for a sensor system
Publication Date: 2017.08.30 FESTO AG & CO KG
  • EP3008426B1 patent drawingFigure 1~2
  • EP3008426B1 patent drawingFigure 3~5
  • EP3008426B1 patent drawingFigure 6

AI summary

The invention relates to a sensor system for determining a position of a measured object (8) in relation to a sensor (7), comprising a sensor (7) for providing a measured value and comprising an evaluating device (22; 30) for evaluating the measured value and for providing an evaluation result. According to the invention, the evaluating device (22; 30) comprises a comparison device, a timing element (43/44), and a memory device (48). The comparison device is designed to compare a stored measured value with a currently determined measured value. The comparison device is also designed to provide a control signal (U3) to the timing element (43/44), so long as a result of the comparison satisfies a specifiable criterion. The timing element (43/44) is designed in such a way that a time measurement process is continued when the control signal (U3) is provided and the time measurement process is restarted when the control signal (U3) is absent. The timing element (43/44) is also designed in such a way that a trigger signal (U4) is output by the timing element (43/44) when a specifiable time span has been reached. The memory device (48) is designed to store the current measured value when the trigger signal (U4) arrives.