Encoder Signal Error Correction for Periodic Position Distortion
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Solution Overview
Problem
Machine operations face inefficiencies due to signal errors in encoder measurements caused by imperfect alignments and external fields, leading to inaccurate incremental control signals.
Innovation Solution
A method for correcting periodic signal errors in position signals by storing time-stamped relative positions, updating them in a moving time window, and determining parameter values for a parameterized approximation to estimate corrected positions, which are then used to generate more accurate control signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If encoder measurements are used directly without correction, then the system is simple and fast, but periodic signal errors occur due to imperfect alignments and external fields
Solution Approach 1:
The patent introduces an intermediary error correction mechanism that processes encoder signals through multiple stages: initial error estimation, periodic error calculation, and corrected signal generation. This intermediary processing layer mediates between the raw encoder measurements and the final control signals, reducing periodic errors while maintaining system architecture
Solution Approach 2:
The system performs preliminary error characterization by analyzing periodic error patterns over multiple rotation periods before generating corrected control signals. By pre-calculating error compensation values based on observed periodic deviations, the system prepares correction data in advance, allowing real-time error reduction without significant processing delays
2Measurement precision
If periodic error correction is implemented, then measurement accuracy improves, but processing time and computational load increase
Solution Approach 1:
The patent exploits the periodic nature of encoder errors by sampling and analyzing error patterns over complete rotation periods. By synchronizing error measurement with the periodic motion of the encoder, the system efficiently captures error characteristics at relevant intervals, reducing the amount of data that needs to be processed while maintaining correction accuracy
Solution Approach 2:
The system applies partial correction by focusing computational resources on correcting the dominant periodic error components rather than attempting to correct all possible error sources. By identifying and correcting only the significant periodic deviations, the system achieves meaningful accuracy improvement with reduced processing requirements compared to comprehensive error correction
3Productivity
If comprehensive error correction is applied, then downstream efficiency improves, but the system becomes more complex and difficult to implement
Solution Approach 1:
The patent divides the error correction process into distinct functional segments: error measurement, periodic pattern analysis, correction calculation, and signal generation. Each segment handles a specific aspect of the correction process, allowing independent optimization and simplifying implementation. This segmentation enables the complex correction task to be broken down into manageable, modular components
Data Source
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AI summary
The present disclosure relates to a method (100) for signal error correction of a position signal relating to a relative position of at least one sensor with respect to a reference. The method comprises determining (S10) a set of parameter values of a parameterized approximation of a corrected relative position with respect to time based on measurements of the position signal over a duration of at least one period of a periodic signal error of the position signal. The method further comprises estimating (S20) a first corrected relative position at a first time based on the parameterized approximation using the determined set of parameter values and the first time. The method also relates to corresponding computer programs, devices and encoders.