Inductive Angular Position Sensors With Magnetic Shielding
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Solution Overview
Problem
Existing inductive angular-position sensors face challenges in accurately determining the angular position of a target with precision and redundancy, especially when multiple sensors are used in conjunction, due to interference and complexity in magnetic field interactions.
Innovation Solution
The design incorporates multiple inductive angular-position sensors with independent sense coils and oscillator coils arranged in a support structure, along with a shield to disrupt magnetic field interactions, allowing for independent and redundant output signals that accurately track the angular position of a target with fins extending above and below the coils.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple inductive angular-position sensors are used to improve measurement precision and redundancy, then the reliability and precision of angular position detection are improved, but the device complexity and magnetic field interference increase
Solution Approach 1:
A magnetic shield is introduced as an intermediary component between multiple inductive angular-position sensors to block and contain magnetic field interactions. The shield prevents magnetic field lines from extending between sensors, thereby reducing interference while allowing the sensors to operate independently and maintain high measurement precision without increasing system complexity
Solution Approach 2:
The sensor system is segmented into isolated units, each with its own oscillator coil and sense coil arrangement. By dividing the system into independent sensor modules separated by magnetic shields, each sensor can accurately detect angular position without being affected by adjacent sensors, thereby improving overall measurement precision while managing device complexity through modular design
2Area of stationary object
If multiple inductive angular-position sensors are arranged close together to reduce space, then the area occupied is reduced, but magnetic field interference between sensors increases
Solution Approach 1:
Magnetic shields are positioned between closely spaced sensors to act as intermediaries that block magnetic field interactions. These shields contain the magnetic fields generated by each sensor's oscillator coil, preventing them from interfering with adjacent sensors while allowing the sensors to be arranged in a compact area
Solution Approach 2:
The magnetic shield configuration is optimized locally between each pair of adjacent sensors. By placing shields only where needed between specific sensor elements rather than throughout the entire array, the design minimizes magnetic field interference while preserving maximum space efficiency in the sensor array layout
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 enhances the precision and redundancy of angular position detection, effectively mitigating interference and ensuring accurate tracking of the target's position through independent and redundant signals from multiple sensors.
Implementation Method 1
An inductive angular-position sensor may include an oscillator, one or more oscillator coils, a first sense coil, a second sense coil, and an integrated circuit. The oscillator may generate an excitation signal. The one or more oscillator coils may be excited by the excitation signal to produce an oscillating signal. The oscillating signal on the one or more oscillator coils may generate a changing (oscillating) magnetic field
Implementation Method 2
The first sense coil and the second sense coil may each encircle a space in which the one or more oscillator coils are capable of generating magnetic field. The changing magnetic field generated by the one or more oscillator coils may induce a first oscillating voltage at ends of the first sense coil and a second oscillating voltage at ends of the second sense coil
Data Source
AI summary
Examples disclosed herein relate generally to inductive angular-position sensors. An example apparatus may include a support structure, a first inductive angular-position sensor, a second inductive angular-position sensor, and a shield. The first inductive angular-position sensor may include a respective first sense coil arranged at a first portion of the support structure. The respective first sense coil may at least partially circumscribe an axis. The second inductive angular-position sensor may include a respective first sense coil arranged opposite the first sense coil of the first inductive angular-position sensor at a second portion of the support structure. The first sense coil of the first inductive angular-position sensor may at least partially circumscribe the axis. The shield may be arranged between the first sense coil of the first inductive angular-position sensor and the first sense coil of the second inductive angular-position sensor.