Rotary Encoder Coupling Slippage Detection Using Acceleration Peaks

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Solution Overview

Problem

Existing rotary encoder systems face challenges in detecting mechanical coupling slippage, which can lead to control system failures and equipment damage if not timely detected.

Innovation Solution

The system determines angular acceleration data from position samples, identifies at least two acceleration peaks, and generates a mechanical coupling error signal when the interval between negative and positive peaks is less than a specified time period, with additional filtering and threshold validation to minimize false positives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical coupling is used to connect driving shaft and driven shaft, then power and motion transfer is achieved, but slippage occurs over time leading to control system failure

Engineering Contradiction:
Improvecoupling reliabilityVSAvoidcoupling service life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The system performs preliminary detection of slippage by continuously monitoring angular acceleration data and identifying characteristic peak patterns before slippage causes control system failure. This early detection allows for preventive maintenance before the coupling completely fails.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback loop where position data is continuously sampled, angular acceleration is calculated, and slippage conditions are detected based on characteristic peak patterns. This feedback enables real-time monitoring and alert generation when coupling degradation is detected.

Inventive Principle:
Principle #23Feedback

2Reliability

If slippage detection is implemented, then control system failure is prevented, but system complexity increases

Engineering Contradiction:
Improvecontrol system reliabilityVSAvoiddetection system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The encoder system performs self-diagnosis by using its own position data to calculate angular acceleration and detect slippage conditions. The existing encoder hardware is utilized to generate diagnostic information without requiring separate sensors or complex additional equipment.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system replaces complex mechanical slippage detection mechanisms with computational analysis of electrical position data. Instead of mechanical sensors or switches, the system uses software-based analysis of angular acceleration patterns to detect slippage.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If acceleration peaks are detected to identify slippage, then detection accuracy is improved, but false positives may occur

Engineering Contradiction:
Improveslippage detection accuracyVSAvoidfalse positive errors
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The system analyzes local characteristics of acceleration data by identifying specific peak patterns (positive and negative peaks within a defined time window). This localized analysis of temporal patterns distinguishes genuine slippage events from random noise or other disturbances.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system changes the parameter being analyzed from raw position data to derived angular acceleration data. By transforming the data and looking for specific patterns in the second derivative, the system enhances the visibility of slippage events while filtering out constant-speed operation and gradual variations.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4241091B1Detection of coupling slippage in rotary encoder systems
Publication Date: 2024.09.04 DYNAPAR CORP
  • EP4241091B1 patent drawingFigure 1
  • EP4241091B1 patent drawingFigure 2
  • EP4241091B1 patent drawingFigure 3

AI summary

Detection of mechanical coupling slippage in rotary encoder systems is provided where position data samples are obtained from a rotary encoder coupled to a rotating element and angular acceleration data is determined based on the position data samples. At least two acceleration peaks are detected in the angular acceleration data, including at least one negative acceleration peak and at least one positive acceleration peak. Slippage occurrence of the mechanical coupling is detected when an interval between a negative acceleration peak and a positive acceleration peak of the at least two acceleration peaks is less than a first time period. If at least a threshold number of slippage occurrences are detected within a second time period, a mechanical coupling error signal is generated.