Partial-Stator Reluctance Angle Sensor for Lightweight Precision Sensing
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Solution Overview
Problem
Conventional reluctance resolvers become economically and physically impractical with increasing diameter due to rising material and weight costs, as well as complex fabrication requirements.
Innovation Solution
A variable reluctance type angle sensor using a stator that covers only a segment of the full circle, with a ferromagnetic core and radially extending teeth, allowing for reduced material usage and weight, and employing a segment-shaped stator with optimized winding schemes to maintain accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional full-circle stator is used in a reluctance resolver, then the sensor provides accurate angular position detection, but the material cost and weight increase significantly with increasing diameter
Solution Approach 1:
The stator is segmented into a partial stator covering only a specific angular range (e.g., 90 degrees or less) rather than forming a complete circle. This segmentation allows the sensor to detect angular positions within a limited range while significantly reducing the amount of ferromagnetic material required, thereby reducing weight and cost without compromising measurement precision within the intended operating range.
2Measurement precision
If a conventional full-circle stator is used in a reluctance resolver, then the sensor provides accurate angular position detection, but the material cost increases significantly with increasing diameter
Solution Approach 1:
The stator is segmented into a partial stator covering only a specific angular range (e.g., 90 degrees or less) rather than forming a complete circle. This segmentation allows the sensor to detect angular positions within a limited range while significantly reducing the amount of ferromagnetic material required, thereby reducing material cost without compromising measurement precision within the intended operating range.
3Measurement precision
If a conventional full-circle stator is used in a reluctance resolver, then the sensor provides accurate angular position detection, but the fabrication complexity increases
Solution Approach 1:
The stator is segmented into a partial stator that can be manufactured as a simpler, smaller component. This reduces fabrication complexity by decreasing the size of the magnetic core, reducing the number of poles required, and simplifying the winding processes. The partial stator can be more easily manufactured with standard tools and assembly procedures.
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
Significantly reduces material costs and weight, simplifies fabrication, and maintains high accuracy and robustness, even in challenging environments, while accommodating limited space applications.
Implementation Method 1
each pole (110) carries one or more windings (112) forming an excitation winding (also referred to as primary winding)
Implementation Method 2
The reluctance within the air gap changes periodically due to the particular form of the rotor which varies around its circumference
Implementation Method 3
a magnetic flux detector is arranged, which detects the intensity of the magnetic field by means of at least two signal pole pairs being off-set to each other by a predetermined angle
Data Source
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AI summary
The present invention relates to a variable reluctance type angle sensor comprising at least one stator (104; 204) with an at least partly ferromagnetic core having a yoke (116; 216) and a plurality of poles (110; 210) which extend from the yoke (116; 216) radially inward toward or outward from a central rotational axis (106; 206) of the angle sensor, wherein an excitation winding and at least one output winding are mounted on the poles (110; 210), a rotor (102; 202) which is operable to rotate around the central rotational axis with respect to the stator and has such a shape that a gap permeance varies in a sine wave manner with respect to an angle of rotation around the central rotational axis. The yoke is shaped to extend along a circular arc around said central rotational axis (106; 206) to cover a yoke angle (124) of less than 360°.