Rotor Alignment Sensing for Accurate Stator Tooth Activation

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Solution Overview

Problem

Existing electric motor systems face challenges in accurately determining rotor alignment and speed without relying on expensive and complex sensors, leading to potential errors in stator tooth activation that can impede rotor rotation or damage supporting circuitry.

Innovation Solution

Implementing a sensorless alignment sensing mechanism using existing motor components, such as coil windings, to estimate rotor alignment and speed, combined with error detection and correction processes that utilize minimal processing and memory resources, including the use of timestamps and counters to manage stator tooth activation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sophisticated rotor speed and position detection processes are implemented, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improverotor speed and position detection accuracyVSAvoidprocessing elements and memory requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The motor's own coil windings are utilized as sensing elements to detect rotor position and speed, eliminating the need for separate expensive sensors. The system serves itself by using existing components for dual purposes: motor operation and position sensing

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The coil windings perform multiple functions: they generate electromagnetic fields for motor operation and simultaneously serve as sensing elements for detecting rotor position and speed through inductance measurements, reducing overall system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If error detection and correction processes are implemented, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvestator tooth activation accuracyVSAvoidprocessing resources and memory
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system continuously monitors rotor position and speed through inductance measurements and uses this feedback to detect errors in stator tooth activation timing, applying corrections based on detected deviations from expected operation

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The error detection implementation uses selective monitoring of critical parameters (inductance changes, timing deviations) rather than comprehensive system monitoring, achieving sufficient reliability with minimal processing overhead

Inventive Principle:
Principle #16Partial or excessive action

3Device complexity

If sensorless alignment sensing mechanism is used, then device complexity is reduced, but measurement precision deteriorates

Engineering Contradiction:
Improvesensor and processing requirementsVSAvoidrotor alignment estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces physical sensors with an electrical sensing mechanism that uses inductance measurements from coil windings to determine rotor position, substituting mechanical/electromechanical sensing with electrical field-based sensing

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The inductance measurements serve as an intermediary parameter that indirectly indicates rotor position and alignment, allowing the system to derive position information without direct physical contact or optical sensors

Inventive Principle:
Principle #24Intermediary (Mediator)

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 accurate rotor alignment and speed estimation with reduced costs and complexity, minimizing errors in stator tooth activation and preventing damage to motor components.

Implementation Method 1

Electromagnetic fields may be formed, such as on a portion of a stator, and the resulting force interaction between a portion of a rotor and the formed electromagnetic field may provide a torque on the rotor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

Implementing a sensorless alignment sensing mechanism using existing motor components, such as coil windings, to estimate rotor alignment and speed

Methodology Applied
Scientific EffectElectromagnetic field interaction: Electromagnetic Induction

Data Source

PatentEP3549253B1Rotor control method and device
Publication Date: 2026.02.25 ARM LTD
  • EP3549253B1 patent drawingFigure 1
  • EP3549253B1 patent drawingFigure 2A
  • EP3549253B1 patent drawingFigure 2B

AI summary

The present techniques generally relate to electric motor which may include one or more sensors usable to determine rotor alignment and/or speed. A method and apparatus for rotor alignment and/or speed error detection and/or correction are proposed, such as using signals from one or more sensors. A method and apparatus for controlling stator tooth activation based, at least in part, on corrections and offsets is also disclosed.