Dual-Rotor Rotary Position Sensor for Multi-Control Redundancy

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Solution Overview

Problem

Conventional rotary position sensors are limited in sensing multiple vehicular controls in close proximity, are costly due to the use of shaped magnets, and lack operational redundancy.

Innovation Solution

A rotary position sensor design featuring two independently rotatable rotors with simple magnets and magnet-effect sensors, along with shielding rings and redundant sensor arrangements, housed in a single sensor unit to provide position information for multiple controls while minimizing manufacturing costs and enhancing operational reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional rotary position sensor uses a single sensor unit, then it can sense the position of one control, but it cannot provide position information for multiple vehicular controls in close proximity

Engineering Contradiction:

Improvecapability to sense multiple controlsVSAvoidsensor unit structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The sensor unit is segmented into multiple independent sensing channels, each comprising a rotor with a magnet and associated sensors. Specifically, the patent employs multiple rotors (first rotor, second rotor) with respective magnets and sensor pairs, allowing each channel to independently sense the position of different vehicular controls simultaneously within a single sensor unit housing.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If a conventional rotary position sensor uses shaped magnets to direct magnetic flux, then it achieves position sensing, but it becomes costly to manufacture

Engineering Contradiction:

Improveposition sensing accuracyVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces expensive shaped magnets with inexpensive rectangular block magnets. The specification explicitly states that 'the magnets may be rectangular block magnets rather than shaped magnets' and that this substitution 'reduces the manufacturing costs associated with the rotary position sensor' while maintaining adequate position sensing functionality through the use of sensor arrays.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If a conventional rotary position sensor uses a single sensing channel, then it reduces device complexity, but it lacks operational redundancy

Engineering Contradiction:

Improveoperational redundancyVSAvoidsensor arrangement

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements redundant sensing channels that can compensate for potential failures. Each control position sensing is achieved through multiple independent sensor elements (first sensor, second sensor for each rotor), providing backup pathways for accurate measurement even if one sensor or magnet fails, thereby ensuring continuous operational reliability.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

4Adaptability or versatility

If multiple magnets and sensors are disposed in close proximity to sense multiple controls, then position information for multiple controls is obtained, but magnetic interference distorts measurement results

Engineering Contradiction:

Improvemulti-control sensing capabilityVSAvoidmagnetic interference

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and eliminates the source of magnetic interference by removing ferromagnetic materials from the sensor housing structure. The specification states that 'the sensor housing may be free of ferromagnetic materials' and that this elimination 'reduces or eliminates magnetic interference' that would otherwise distort the magnetic fields generated by the magnets and affect sensor measurements.

Inventive Principle:

Principle #2Taking out (Extraction)

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

Enables cost-effective and redundant position sensing for multiple vehicular controls, reducing magnetic interference and improving signal linearity, thus providing robust and reliable position data across a wide range of rotations.

Implementation Method 1

magnet-effect sensors (e.g., Hall-effect, Anisotropic Magneto-Resistive sensors, Giant magnetoresistance, and Tunnel magnetoresistance sensors)

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

magnet-effect sensors (e.g., Hall-effect, Anisotropic Magneto-Resistive sensors, Giant magnetoresistance, and Tunnel magnetoresistance sensors)

Methodology Applied

Scientific EffectHall-effect: Hall Effect

Data Source

PatentEP3548847B1Rotary position sensor with plurality magnet arrangement

Publication Date: 2024.04.03 SUZHOU LITTELFUSE OVS LTD

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AI summary

A rotary position sensor (102) may include a sensor housing (202) defining an interior cavity. A first rotor (206) may be positioned and rotatable within the interior cavity, and includes a first magnet (326). Furthermore, the rotary position sensor (102) may include a second rotor (208) positioned and rotatable within the interior cavity. The second rotor (208) includes a second magnet (328). The first rotor (206) and the second rotor (208) may be individually rotatable.