Photoelectric Sensor Dynamic Pulse Control for Energy and Interference

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Solution Overview

Problem

Existing photoelectric sensors face challenges in energy saving and anti-interference performance, with previous technologies not adequately addressing these issues.

Innovation Solution

A photoelectric sensor system that includes a system clock generating unit, frequency dividing unit, and selection unit, which dynamically adjusts the duty cycle and sleep cycle based on the size and speed of detected objects to optimize energy consumption and reduce interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the oscillation circuit uses a fixed pulse width and fixed period, then the detection stability is maintained, but the energy consumption is high

Engineering Contradiction:
Improvedetection stabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by transitioning from a fixed pulse period to a variable pulse period system. The control unit dynamically adjusts the pulse period between a first period (when no object is detected) and a second period (when an object is detected), allowing the system to adapt its operation mode based on detection needs while maintaining detection stability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent utilizes periodic action by implementing different pulse periods for different operational states. The oscillation circuit generates light projecting pulses with a first period during normal operation and switches to a second period when object detection occurs, creating a periodic pattern that optimizes both energy consumption and detection capability

Inventive Principle:
Principle #19Periodic action

2Use of energy by moving object

If the pulse period is extended to save energy, then the energy consumption is reduced, but the anti-interference performance deteriorates

Engineering Contradiction:
Improveenergy consumptionVSAvoidanti-interference performance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system dynamically adjusts the pulse period based on detection state, switching between a longer first period for energy saving and a shorter second period for improved anti-interference performance during object detection, thereby maintaining reliability while reducing overall energy consumption

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the temporal parameter (pulse period) of the light projecting pulses based on detection conditions. By adjusting the period parameter between two distinct values, the system optimizes the balance between energy consumption and anti-interference performance for different operational scenarios

Inventive Principle:
Principle #35Parameter changes

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 achieves energy savings and improved detection accuracy by selectively using longer or shorter pulse cycles based on object presence and movement, effectively reducing power consumption and enhancing anti-interference capabilities.

Implementation Method 1

a light emitting element 52 for emitting light

Methodology Applied
Scientific EffectLight emission: Light Emitting Diode

Implementation Method 2

a light receiving element 62 for receiving the light coming from the light emitting element 52

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP3211457B1Photoelectric sensor and control method thereof
Publication Date: 2020.01.08 OMRON CORP
  • EP3211457B1 patent drawingFigure 1
  • EP3211457B1 patent drawingFigure 2
  • EP3211457B1 patent drawingFigure 3

AI summary

A photoelectric sensor and a control method thereof are provided, the photoelectric sensor (1) includes a driving pulse generating unit; a light-emitting part (5), receiving the driving pulse to emit light; a light receiving part (6), receiving the light reflected by a detected object to generate a light receiving signal; an output unit (7), processing the light receiving signal to output a detection signal; and a control unit (8), controlling the driving pulse generating unit to generate a first driving pulse of a sleep cycle (T2) in usual, and triggered by a variation of the detection signal to control the driving pulse generating unit to generate a specified number of second driving pulses of a duty cycles, the duty cycle is formed by two or more specific cycles, an average of the specific cycles serves as the duty cycle, and the duty cycle is shorter than the sleep cycle (T2).