Resolver Angle Detection via Digital Correlation
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Solution Overview
Problem
Existing methods for detecting the rotation angle of a rotating shaft using resolvers face challenges in precision and speed, especially at high rotor speeds, due to delays and errors in signal evaluation.
Innovation Solution
A method employing a resolver with a first and second stator winding, where an excitation signal is generated and applied to these windings, inducing a resolver signal in the rotor winding, which is then processed through a phase shifter, correlator, and controller to produce an output signal that quickly and accurately represents the rotor's angle of rotation between 0° and 360°, utilizing harmonic alternating voltages and an integrating controller for precise evaluation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional resolver signal evaluation methods are used, then the system is simple to implement, but the detection precision and speed deteriorate at high rotor speeds
Solution Approach 1:
The patent replaces conventional mechanical signal evaluation methods with a digital signal processing system. A digital correlator multiplies the resolver signal with correlation signals to directly compute the rotation angle, substituting analog processing with digital computation to achieve higher precision and speed without proportionally increasing system complexity
Solution Approach 2:
The patent changes the evaluation method from direct voltage measurement to correlation-based parameter extraction. By using correlation signals that are phase-shifted versions of the resolver signal, the system extracts angle information through multiplication and integration, transforming the measurement parameter from voltage level to phase relationship
2Productivity
If conventional resolver signal evaluation methods are used, then the device structure is simple, but the detection speed deteriorates at high rotor speeds
Solution Approach 1:
The patent substitutes traditional analog signal evaluation with digital signal processing. The digital correlator performs rapid multiplication and integration of the resolver signal with correlation signals, enabling high-speed detection that keeps pace with high rotor speeds while maintaining a relatively simple device structure through standardized digital processing blocks
Solution Approach 2:
The patent prepares correlation signals in advance that are phase-shifted versions of the expected resolver signal. These pre-computed correlation signals are stored and ready for immediate multiplication with the incoming resolver signal, eliminating the need for real-time signal generation and enabling faster detection response
3Loss of time
If conventional resolver signal evaluation methods are used, then the system is easy to implement, but delays occur in signal evaluation
Solution Approach 1:
The patent replaces sequential analog signal processing with parallel digital computation. The digital correlator simultaneously multiplies the resolver signal with multiple phase-shifted correlation signals and integrates the results, eliminating sequential processing delays and achieving real-time angle detection without significant time loss
Solution Approach 2:
The patent maintains continuous signal evaluation by using an integrating controller that continuously integrates the product of the resolver signal and correlation signals. This continuous integration process eliminates discontinuous measurement intervals, ensuring uninterrupted angle detection and minimizing evaluation delays
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 rapid and accurate detection of the shaft's rotation angle without significant delay, even at high rotor speeds, by generating a control signal that regulates to zero, correlating the rotor speed and angle with harmonic signals, ensuring precise and error-free evaluation.
Implementation Method 1
an excitation signal with an excitation frequency is generated by a frequency generator; a first stator signal with the excitation frequency is supplied to the first stator winding; a second stator signal with the excitation frequency is supplied to the second stator winding; a resolver signal with a resolver frequency is induced in the rotor winding
Data Source
Figure 1
AI summary
The invention relates to a method for detecting an angle of rotation of a rotating shaft (17) by means of a resolver (10), which has a first stator winding (11), a second stator winding (12) and a rotor winding (15), wherein: an exciter signal (S20) is generated by a frequency generator (20); a first stator signal (S71) is fed to the first stator winding (11); a second stator signal (S72) is fed to the second stator winding (12); a resolver signal (S10) is induced in the rotor winding (15); the resolver signal (S10) is output by the resolver (10); the resolver signal (S10) is fed to a phase shifter (30), which generates a first correlator signal (S31) and a second correlator signal (S32); the correlator signals (S31, S32) are fed to a correlator (40); a control signal (S40) is generated and output by the correlator (40); the control signal (S40) is fed to a controller (50); an output signal (S50) is generated and output by the controller (50); the output signal (S50) and the exciter signal (S20) are added to form an actuation signal (S60); a first comparison signal (S81) and a second comparison signal (S82) are generated and fed to the correlator (40). The invention also relates to a device for detecting an angle of rotation of a rotating shaft (17), which is designed to carry out the method according to the invention.