Encoder Position Correction Using Regression Prediction

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Solution Overview

Problem

Encoders face accuracy issues due to assembly errors and environmental factors, leading to decreased precision over time, which existing technologies have not effectively addressed.

Innovation Solution

An instant correction method for encoders that involves sensing motion to obtain wave signals with a 90-degree phase difference, sampling these signals to generate digital values, performing regression analysis to predict positions, and applying error values to correct the encoder's output, thereby maintaining accuracy and extending its lifespan.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If regression analysis is performed on N positioning positions to predict (N+1)-th position, then encoder accuracy is improved, but calculation time and processing complexity increase

Engineering Contradiction:
Improveencoder position accuracyVSAvoidcorrection calculation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent pre-calculates and stores a lookup table containing correction values for different position ranges before actual operation. During real-time correction, the system only needs to query the pre-computed table rather than performing full regression analysis, thus maintaining high accuracy while reducing calculation time to minimal lookup operations

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent divides the position range into multiple segments or intervals, and performs regression analysis only for the current active segment rather than the entire position range. This segmentation reduces the number of data points N required for each correction calculation, thereby reducing computation time while maintaining local accuracy

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If continuous correction is applied to maintain encoder accuracy, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveencoder position accuracyVSAvoidcorrection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a self-correction mechanism where the encoder system automatically detects and corrects its own position errors using built-in sensors and processing units. The system performs self-diagnosis and self-adjustment without requiring external calibration equipment or manual intervention, thereby maintaining high accuracy while avoiding the complexity of external correction systems

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent establishes a feedback loop where the encoder continuously monitors its own position output, compares it with expected values, and automatically applies corrections based on the detected deviations. This closed-loop feedback mechanism maintains accuracy automatically without requiring complex external control systems

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3677873B1Instant correction method for encoder and system thereof
Publication Date: 2021.09.15 DELTA ELECTRONICS INC(CN)
  • EP3677873B1 patent drawingFigure 1
  • EP3677873B1 patent drawingFigure 2A~2B
  • EP3677873B1 patent drawingFigure 3

AI summary

An instant correction method for an encoder includes the following steps. The motion of a device under test is sensed to obtain a first wave signal and a second wave signal. The first and second wave signals are sampled to generate N first digital signal values and N second digital signal values. N positioning positions are generated according to the N first and second digital signal values, and the N positioning positions are added to a calculation group. A regression analysis is performed for the calculation group to generate a regression curve. The (N+1)-th prediction position is predicted using the regression curve. The ideal position of the device under test is determined at a time point of the (N+1)-th prediction position according to an ideal position curve. An error value between the (N+1)-th prediction position and the ideal position is applied to correct the device under test.