Angle Calibration via Magnet Wheel Voltage Feedback

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Solution Overview

Problem

Existing electrical machines face challenges in reliably determining the angular position of the rotor due to installation tolerances and external influences, leading to inaccuracies and potential errors in angle measurement.

Innovation Solution

An electrical machine with an angular position sensor, a stator winding for generating a magnetic field, a voltmeter for detecting magnet wheel voltage, and a determination circuit to calculate the angle difference between the rotor's actual and measured positions, allowing for regular plausibility checks and precise angle calibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an angular position sensor is used to determine the rotor position, then the angle measurement is available for control purposes, but installation tolerances and external influences cause inaccuracies and potential errors in angle measurement

Engineering Contradiction:
Improveangle measurement precisionVSAvoidreliability of angle measurement
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the magnet wheel voltage signal is continuously monitored and compared against expected values. The determination circuit processes this voltage to detect deviations caused by installation tolerances or external influences, and generates correction signals to compensate for these errors, thereby maintaining reliable angle measurement despite initial inaccuracies

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces the magnet wheel voltage signal as an intermediary element that serves as a reference for validating the angular position sensor measurements. By comparing the sensor output against the magnet wheel voltage-derived angle, the system can detect and correct measurement errors without requiring additional sensors or complex calibration procedures

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If the magnet wheel voltage is used for angle calibration, then the zero position can be determined simply and cost-effectively, but the system requires additional circuitry for voltage detection and comparison

Engineering Contradiction:
Improveease of angle calibrationVSAvoidcomplexity of calibration circuitry
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent achieves multi-functionality by utilizing the existing stator winding and rotor structure to generate the magnet wheel voltage signal, which serves dual purposes: it is used for normal electrical machine operation and simultaneously serves as a reference signal for angle calibration and validation. This eliminates the need for separate calibration hardware while adding calibration capability to the existing system

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

Solution Approach 2:

The electrical machine structure itself provides the calibration reference through the magnet wheel voltage generated during normal operation. The system uses its own operational characteristics (the voltage induced in the stator winding by the rotating rotor) as the calibration standard, eliminating the need for external calibration equipment or additional sensors

Inventive Principle:
Principle #25Self-service

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 solution enables a reliable and precise determination of the rotor's angular position, detecting changes caused by twisting or external factors, and prevents incorrect operation by correcting the angle signal, thereby enhancing the overall reliability of the angle measurement.

Implementation Method 1

a stator winding (107) for generating a magnetic field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a voltmeter (109) for detecting a magnet wheel voltage at the ends of the stator winding (107) when the rotor (105) rotates

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2817592B1Calibrating and monitoring an angle detecting system for electrical machines
Publication Date: 2018.03.28 SEG AUTOMOTIVE GERMANY GMBH
  • EP2817592B1 patent drawingFigure 1
  • EP2817592B1 patent drawingFigure 2
  • EP2817592B1 patent drawingFigure 3~4

AI summary

The invention relates to an electrical machine (100) having an angular position sensor (103) for determining a first rotation angle of a runner (105) of a stator winding (107) for producing a magnetic field, a voltmeter (109) for capturing a magnet-wheel voltage at the ends of the stator winding when the runner rotates, and a determination circuit (111) for determining a second rotation angle from the magnet-wheel voltage and for determining an angle difference between the first and the second rotation angle.