Angle Detection Device Harmonic Error Correction

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Solution Overview

Problem

Existing angle detection devices struggle to correct angle errors caused by harmonic components and low orthogonality in sine and cosine signals, and fail to effectively address components of other orders than the electrical angle frequency component.

Innovation Solution

An angle detection device that multiplies the angle signal by a real number n, generates sine and cosine wave signals of differing phases, and uses offset correction values to correct the angle signal, ensuring accurate detection even with harmonic components and low orthogonality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If center point correction is applied to sine and cosine signals, then electrical angle frequency component accuracy is improved, but harmonic components and other order components cannot be corrected

Engineering Contradiction:

Improveelectrical angle frequency component accuracyVSAvoidcorrection capability for harmonic components

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent segments the angle signal into multiple frequency components (electrical angle frequency component, harmonic components, and other order components) and applies separate correction processes for each component type, enabling comprehensive correction across all signal orders

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the correction parameters by introducing multiple correction values (first correction value for electrical angle frequency component, second correction value for harmonic components, third correction value for other order components) instead of a single center point correction value, allowing adaptive correction for different signal characteristics

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If offset correction is applied to electrical angle frequency component, then that component is corrected well, but components of other orders remain uncorrected

Engineering Contradiction:

Improveelectrical angle frequency component correctionVSAvoidoverall angle detection accuracy

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent creates a universal correction mechanism that handles multiple types of angle signal components (electrical angle frequency, harmonic, and other order components) through a unified correction architecture that applies appropriate correction values for each component type, making the system multi-functional in terms of correction capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12044554B2Angle detection device, and electric power steering device using same

Publication Date: 2024.07.23 MITSUBISHI ELECTRIC CORP

AI summary

A second n-fold angle signal is calculated using a first sine wave signal and a second sine wave signal obtained from a first n-fold angle signal that is an angle signal multiplied by n (n is a real number other than 1), offset correction values of the first sine wave signal and the second sine wave signal respectively are calculated from the second n-fold angle signal, the first sine wave signal is corrected by the calculated offset correction value of the first sine wave signal being added to the first n-fold angle signal, and the second n-fold angle signal is corrected by the calculated offset correction value of the second sine wave signal being added to the second sine wave signal.