Inductive Angular Position Sensor Star-Connected Coils
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Solution Overview
Problem
Existing inductive angular position sensors have high manufacturing and usage costs, as well as significant consumption, while also being vulnerable to external electromagnetic disturbances and tampering attempts.
Innovation Solution
The proposed inductive angular position sensor uses a stator with a primary coil and three secondary coils connected in a star shape, where the rotary disk is partially metallized or surrounded by a coil, allowing for unambiguous angular position determination with reduced component count and improved robustness against disturbances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional inductive angular position sensors use multiple secondary coils arranged symmetrically in pairs, then resistance to electromagnetic disturbances and tampering is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
The patent extracts only the essential functional elements needed for reliable operation. Instead of using symmetric pairs of secondary coils (which would require 4 or more coils), the invention uses a minimal configuration of just 3 secondary coils arranged in a star connection, removing redundant components while maintaining disturbance resistance through the inherent symmetry of the star configuration and the rotary disk with metallized sectors.
Solution Approach 2:
The three secondary coils in star connection serve multiple functions simultaneously: they provide the necessary signal for angular position detection, create inherent resistance to electromagnetic disturbances through their symmetric arrangement, and enable unambiguous position determination when combined with the rotary disk having metallized sectors. This multi-functionality eliminates the need for additional coils that would be required in traditional symmetric pair configurations.
2Reliability
If traditional inductive angular position sensors use multiple secondary coils arranged symmetrically in pairs, then measurement reliability is improved, but manufacturing cost increases
Solution Approach 1:
The patent removes redundant secondary coils from the traditional symmetric pair configuration, retaining only the minimum number (3 coils) necessary to achieve reliable measurement. This extraction of essential elements reduces the bill of materials and assembly complexity, directly lowering manufacturing cost while preserving measurement reliability through the star connection topology and rotary disk interaction.
Solution Approach 2:
The patent changes the configuration parameter from symmetric pairs (requiring 4+ coils) to a star connection arrangement (using exactly 3 coils). This parameter change in the coil arrangement topology maintains the ability to detect angular position reliably while reducing the total number of coils, thereby reducing manufacturing cost.
3Reliability
If traditional inductive angular position sensors use symmetric pair configurations of secondary coils, then robustness against tampering is improved, but energy consumption increases
Solution Approach 1:
The patent extracts unnecessary coils from the traditional configuration, using only 3 secondary coils instead of the 4 or more required by symmetric pair arrangements. This reduction in component count directly lowers the energy consumption of the sensor while maintaining robustness against tampering through the inherent symmetry and signal processing capabilities of the star-connected three-coil system combined with the metallized rotary disk.
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
This configuration enables unambiguous angular position measurement with a reduced number of secondary coils, enhancing manufacturing cost-effectiveness, robustness against external disturbances, and autonomy, while maintaining the advantages of inductive sensors.
Implementation Method 1
a primary coil which generates an electromagnetic excitation field when powered by an electrical source, and a plurality of secondary coils, the excitation of which is caused by the generated electromagnetic field
Implementation Method 2
Angular position is determined by comparing the induced voltages observed in the secondary coils when a rotary disk of the rotor, upon rotating about its axis of revolution, interferes with the electromagnetic field generated in a different manner depending on its position of rotation, as a result of Foucault's currents appearing in the disk
Data Source
Figure 1~2
Figure 3~4
AI summary
The present invention relates to an inductive angular position sensor (1), comprising a stator (2) and a rotor (3). The stator (2) is provided with a primary coil (21) and a plurality of secondary coils (22, 23, 24). The rotor (3) is provided with a rotary disk (4) rotating about its axis of revolution (5). The inductive sensor (1) is characterized in that it comprises only three secondary coils (22, 23, 24) connected to one another in a star shape, such that the primary coil (21) causes the simultaneous excitation of same, with the corresponding voltages induced in the secondary coils (22, 23, 24) being processed to obtain the angular position by comparing at least two of the three induced voltages or a combination thereof (UAB, UBC, UCA).