Phase Extraction Method for Rotating Systems
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Solution Overview
Problem
Existing methods for extracting phase information from rotating systems using capacitive angular sensors require a full data set of N points, leading to a time lag of one period of the periodic modulation function, resulting in significant error margins, especially in systems with rapidly changing phase information.
Innovation Solution
The method involves sampling and storing output values from capacitive angular sensors at N points during a period, using a function Fk(t) that adapts phase information extraction after each reading, allowing for immediate updates by replacing oldest samples with new ones, and utilizing a LILO memory principle and shift registers for efficient calculation and storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a full data set of N points is used for phase information extraction, then measurement precision is improved, but loss of time increases due to one period delay
Solution Approach 1:
The patent pre-calculates and stores root functions (rcos and rsin) for the discrete Fourier transform before they are needed. By preparing these computational elements in advance, the system can perform phase extraction immediately when new sensor data arrives, eliminating the one-period delay that would otherwise be required to accumulate N complete data points.
Solution Approach 2:
The patent segments the phase extraction process into independent computational components that can be updated incrementally. Instead of requiring complete N-point data sets, the system processes individual sensor samples sequentially, updating phase information with each new measurement using the pre-prepared root functions, thus achieving continuous real-time extraction without waiting for full periods.
2Productivity
If sampling frequency is increased to reduce time lag, then productivity is improved, but device complexity increases
Solution Approach 1:
The root functions required for high-speed phase extraction are pre-calculated and stored in memory before operation. This preliminary preparation allows the system to perform rapid sequential updates using simple multiplication and addition operations on incoming sensor data, achieving high sampling speeds without requiring complex real-time computational hardware.
Data Source
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AI summary
The invention relates to a Method for obtaining information on the phase of a rotating system based on determination of the fundamental component of an incoming signal provided by a sensor (110) driven by a periodic modulation function (PHA,PHB,PHC, PHD) with angular frequency ω, said method comprising the steps of a) reading the present output value Sk, (k=0,...,N-1) of the sensor at a sequence of N points of time during a first period of the periodic modulation function (PHA,PHB,PHC, PHD), b) storing read output values Sk or a value derived from this output value at least temporarily in a memory, c) extracting information on the phase of the rotating system, wherein said information is extracted based on evaluation of a function of the type Fkt=∑j=k-N+1kSj[fcNjt+ ifsNjt)], wherein fc(N,j,t)=cos(((j mod N) - 1) · [ωt + φ(N)]) and fs(N,j,t) = sin(((j mod N) - 1)[ωt + φ(N)]), and d) sampling and storing sequentially further output values Sk, k=N,N+1,... of the sensor at corresponding points of time in the following periods of the periodic modulation function (PHA,PHB,PHC, PHD), wherein after each reading information on the phase of the rotating system based on the function Fk(t) is extracted and a controller device (100) for application of this method.