Resolver Converter DDS Noise Detection for Motor Angle Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The output signal of a resolver used to detect motor rotation angles is contaminated with noise, requiring frequency analysis that necessitates a Fourier transform circuit or high-speed CPU, leading to increased circuit size in motor control devices.
Innovation Solution
A resolver converter with a tracking loop circuit that operates as a direct digital synthesizer (DDS) to synchronously detect noise signals in the resolver output, allowing for noise detection without expanding the circuit size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frequency analysis is performed using Fourier transform circuit or high-speed CPU, then noise detection accuracy is improved, but circuit size increases
Solution Approach 1:
The invention extracts only the necessary frequency component (rotation frequency and its harmonics) from the resolver output signal using a tracking loop circuit, rather than performing full spectrum Fourier transform analysis. This extraction approach maintains noise detection accuracy while avoiding the need for large Fourier transform circuits or high-speed CPUs.
Solution Approach 2:
The tracking loop circuit serves multiple functions: it tracks the rotation angle of the motor, generates synchronous detection signals, and enables noise detection at specific frequency components. This multi-functionality eliminates the need for separate Fourier transform circuitry, reducing overall circuit size while maintaining detection capabilities.
2Difficulty of detecting and measuring
If Fourier transform circuit is added for frequency analysis, then noise signal detection is improved, but device complexity increases
Solution Approach 1:
The invention replaces the complex Fourier transform circuit (electronic/mechanical system) with a tracking loop circuit that uses synchronous detection based on rotation frequency tracking. This substitution maintains the ability to detect noise signals while significantly reducing circuit complexity by avoiding the need for multiple multipliers, accumulators, and control logic required for Fourier transform.
3Productivity
If high-speed CPU is used for Fourier transform, then frequency analysis capability is improved, but productivity is reduced due to increased processing time
Solution Approach 1:
The tracking loop circuit continuously tracks the rotation frequency and maintains synchronous detection signals ready for noise analysis. This preliminary preparation of detection signals eliminates the need for computationally intensive real-time Fourier transform processing, enabling fast noise detection without sacrificing frequency analysis capability.
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 detection of noise or damage waves on the resolver output without increasing the circuit size of the motor control device, effectively processing noise signals within existing hardware constraints.
Implementation Method 1
the control and diagnosis circuit, by operating the tracking loop circuit as a direct digital synthesizer (DDS), synchronously detects a noise signal superimposed on the resolver output signal
Implementation Method 2
synchronously detects a noise signal superimposed on the resolver output signal
Data Source
AI summary
A resolver converter includes a tracking loop circuit that calculates an angle θ from a resolver output signal, a control and diagnosis circuit that controls the tracking loop circuit and diagnoses based on the resolver output signal, wherein the control and diagnosis circuit, by operating the tracking loop circuit as a direct digital synthesizer (DDS), synchronously detects a noise signal superimposed on the resolver output signal.