Resolver Correction Device Phase Shift Stability
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Solution Overview
Problem
Existing resolver correction devices face challenges in correcting frequency deviations caused by rotor rotation and temperature variations in analog filters, leading to inaccuracies in phase shift amounts and signal processing.
Innovation Solution
A resolver correction device that uses a phase shifter, frequency error correction unit, and adjuster to calculate and adjust the phase shift amount based on the time differential of the phase difference between phase modulation and excitation signals, correcting frequency deviations and temperature-induced variations in the phase shift amount.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If analog elements (resistor and capacitor) are used for filters, then the filter can be implemented with simple circuit structure, but the element characteristic varies according to temperature change causing shift amount difference
Solution Approach 1:
The patent employs feedback mechanisms where the actual phase shift amount is detected and compared with the target value, and the detected element characteristics are used to generate correction signals that adjust the filter parameters in real-time, compensating for temperature-induced variations
Solution Approach 2:
The patent dynamically changes the parameters of the analog filter (such as resistance or capacitance values) based on detected temperature or element characteristic variations, allowing the filter to maintain its intended phase shift performance despite environmental changes
2Reliability
If element specified value is adjusted to cancel temperature change, then temperature stability is improved, but frequency deviation according to rotor rotation cannot be corrected
Solution Approach 1:
The patent separates the correction of temperature effects from the correction of frequency deviations by using different correction mechanisms: one for stabilizing element characteristics against temperature and another for correcting rotor-induced frequency variations
Solution Approach 2:
The patent implements dynamic correction where the filter parameters are continuously adjusted based on real-time detection of both temperature conditions and rotor rotation state, allowing the system to adapt to changing operating conditions
3Reliability
If phase shift amount is controlled to predetermined value using APF replica, then temperature variation is compensated, but frequency deviation error cannot be corrected
Solution Approach 1:
The patent uses feedback from phase difference detectors to continuously monitor and correct the phase shift amount, ensuring that both temperature-induced and frequency-induced deviations are compensated by comparing actual phase with target phase and adjusting accordingly
Data Source
AI summary
To correct a frequency deviation generated in an input signal to an analog filter according to the rotation of a rotor in a resolver, a resolver correction device includes a phase shifter which shifts the phase of a first phase signal of the resolver, with respect to the signals at least having two phases and more, detected by the resolver. The phase-shifted first phase signal and a second phase signal are added, as a phase modulation signal with the excitation signal modulated by a rotation angle of the rotor in the resolver. A phase difference correction signal is generated based on a phase difference between the phase modulation signal of the resolver and the excitation signal. The adjusting amount of the phase shifter is calculated based on the phase difference correction signal, in which the phase shifter adjusts a phase shift amount according to the adjusting amount.