Multi-turn Angle Sensor Using Magnetic Mediator for 1440-Degree Range
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Solution Overview
Problem
Current multi-turn sensors fail to provide a reliable and accurate sensing range of at least 1440-degrees, which is essential for various industrial and vehicular applications, due to limitations in their design and functionality.
Innovation Solution
A multi-turn non-contact sensor design featuring a rotationally mounted driver magnet and a driven magnet with a greater number of magnetic poles, where the driven magnet rotates one complete revolution for every predetermined number of revolutions of the driver magnet, enabling a minimum sensing range of 1440-degrees with improved reliability and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional multi-turn sensor designs are used, then device complexity is reduced, but sensing range and measurement precision deteriorate (cannot achieve 1440-degrees or more with adequate reliability)
Solution Approach 1:
The patent introduces an intermediate driven magnet as a mediator between the driver magnet and the magnetic sensor. This driven magnet receives magnetic force from the driver magnet and transmits rotational motion with reduced speed and increased torque. The intermediate magnet enables multi-turn sensing by converting the driver magnet's rotations into precise angular position measurements over extended ranges (1440-degrees or more) while maintaining system reliability through magnetic coupling rather than direct mechanical contact.
Solution Approach 2:
The patent replaces traditional mechanical transmission systems with a magnetic field-based transmission system. Instead of using mechanical gears, belts, or direct contact mechanisms to achieve multi-turn sensing, the invention uses magnetic forces between the driver magnet, driven magnet, and magnetic sensor to transmit rotational information. This substitution eliminates mechanical wear, reduces friction, and enables non-contact sensing while achieving the required sensing range and measurement precision.
2Measurement precision
If the driven magnet has more magnetic poles (P2>P1), then measurement precision and sensing range improve, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs feedback mechanisms where the magnetic sensor continuously monitors the angular position of the driven magnet and provides output signals that reflect the actual position. This feedback allows the system to compensate for minor manufacturing variations in magnetic pole alignment through electronic correction algorithms. The output circuit processes sensor signals to determine absolute angular position and rotational speed, effectively compensating for manufacturing tolerances and maintaining high measurement precision despite the complexity of manufacturing multiple precisely aligned magnetic poles.
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 sensor achieves a minimum sensing range of 1440-degrees with enhanced reliability and accuracy, capable of determining absolute angular position and rotational speed, while maintaining low linearity and hysteresis errors.
Implementation Method 1
The driven magnet is spaced apart from, and is coupled to receive a magnetic force from, the driver magnet
Data Source
AI summary
A multi-turn non-contact sensor includes a rotationally mounted driver magnet, and a rotationally mounted driven magnet. The driver magnet has a first number (P1) of magnetic poles and is configured to selectively receive a rotational drive torque and, upon receipt of the drive torque, to rotate about a first rotational axis. The driven magnet is spaced apart from, and is coupled to receive a magnetic force from, the driver magnet. The driven magnet has a second number (P2) of magnetic poles and is responsive to rotation of the driver magnet to rotate about a second rotational axis that is parallel to the first rotational axis. The driven magnet rotates one complete revolution each time the driver magnet rotates a predetermined number (N) of complete revolutions, P2>P1, and N=(P2/P1).