Arc-Motion Position Encoder Correction for Radial Offset Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing measuring instruments with arc motion and electronic position encoders face challenges in achieving a desirable combination of compact size, high resolution, accuracy, and robustness to contamination, particularly in test indicators and lever-type dial gauges.
Innovation Solution
The measuring instrument incorporates a movable encoder portion configured for arc motion with an electronic position encoder that includes a detector and scale portion, utilizing a field generating portion to generate changing magnetic flux and sensing elements to determine an absolute relative position, correcting for radial offsets using signal processing to enhance measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional electronic position encoder is used in a measuring instrument with arc motion, then the instrument can perform measurements, but the combination of compact size, high resolution, accuracy, and robustness to contamination cannot be simultaneously achieved
Solution Approach 1:
The encoder is divided into two separate portions: a detector portion and a scale portion. The detector portion includes field generating portions and sensing portions with first and second sets of sensing elements, while the scale portion includes first and second scale element portions with corresponding signal modulating scale elements. This segmentation allows each portion to be optimized independently for compact size and robustness while maintaining high measurement accuracy through the coordinated interaction of the segmented components.
2Volume of moving object
If the encoder portions are arranged close together to reduce size, then compact size is achieved, but radial offset errors increase measurement inaccuracy
Solution Approach 1:
The patent implements a correction process that uses signal processing to detect and compensate for radial offset errors between the detector portion and scale portion. The system continuously monitors the relative position and applies correction values to the measured position data, allowing the encoder portions to be arranged compactly without sacrificing measurement accuracy. This feedback mechanism enables the system to maintain high precision despite the close proximity of the encoder portions.
3Device complexity
If single-track encoders are used to simplify the structure, then device complexity is reduced, but resolution and accuracy are insufficient for precise measurements
Solution Approach 1:
The patent merges two independent encoder tracks into a single integrated encoder system. The first track includes the first set of sensing elements and first scale element portions, while the second track includes the second set of sensing elements and second scale element portions. By combining both tracks and processing their signals together through the correction process, the system achieves higher resolution and accuracy than single-track encoders while maintaining manageable structural complexity through the unified design.
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 solution provides improved measurement accuracy and robustness to contamination while maintaining a compact size and low cost, suitable for precise measurements in small deflection applications.
Implementation Method 1
The detector portion includes a field generating portion configured to generate changing magnetic flux in response to drive signals
Implementation Method 2
The sensing portion includes a first sensing element portion comprising a first set of first sensing elements and arranged in a first track portion with the first scale element portion
Data Source
AI summary
A measuring instrument includes a movable portion configured to rotate in an arc motion about a pivot portion, and an electronic position encoder configured to measure an absolute relative position between a detector portion and a scale portion, one of which forms part of the movable portion. A maximum movement range of the movable encoder portion and a maximum absolute measurement range are each less than 360 degrees. Based at least in part on detector signals that are received from the detector portion, an offset value is determined that corresponds to a radial offset (e.g., of the scale portion or the detector portion). The determined offset value is utilized to correct one or more values that are utilized to determine a relative position between the detector portion and the scale portion (e.g., such as a value corresponding to a spatial step or other spatial value of the scale portion).