Pulsating Voltage Acquisition With Isolated Edge Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional methods for measuring voltage values in electric motors are susceptible to noise interference and time delays, leading to inaccurate calculations due to phase shifts and insufficient filtering quality, which affects the accuracy of voltage values provided to motor models.
Innovation Solution
An information acquisition device and method that utilizes a signal isolation circuit and signal processing module to filter noise from pulsating voltage without causing phase delays, allowing for accurate calculation of voltage duty cycles and averaged values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a low-pass filter is used to eliminate noise from the analog pulsating wave profile, then the filtering quality is improved, but the time delay and phase changes are significantly increased
Solution Approach 1:
The patent replaces the traditional mechanical/analog filtering approach with a digital signal processing approach. Instead of using an analog low-pass filter that introduces time delays, the system uses a digital filter applied to the sampled pulsating wave profile. This substitution allows for effective noise filtering while maintaining temporal accuracy and avoiding phase shifts, as digital filtering can be performed without the inherent time constants that plague analog filters.
2Measurement precision
If the analog pulsating wave profile is filtered with high quality, then noise is reduced, but the time delay increases and phase changes become difficult to quantify
Solution Approach 1:
The patent replaces analog filtering with digital filtering to preserve phase information. Digital signal processing allows for filtering operations that do not introduce unquantifiable phase shifts, maintaining the integrity of the pulsating wave profile's temporal characteristics while still achieving effective noise reduction.
Solution Approach 2:
The patent performs sampling and digital filtering in a predetermined sequence that preserves phase relationships. By establishing a fixed sampling rate and applying digital filters with known phase characteristics, the system can compensate for or eliminate phase delays before further processing, thus preventing information loss.
3Loss of time
If filtering quality is reduced to decrease time delay, then time delay is reduced, but high frequency noise is retained
Solution Approach 1:
The patent uses digital filtering instead of analog filtering to achieve effective noise reduction without the time delay penalties. Digital filters can be designed with linear phase characteristics or phase compensation can be applied, allowing for aggressive noise filtering while maintaining temporal fidelity and not sacrificing time delay performance.
Data Source
AI summary
The present invention provides an information acquisition device and method for a pulsating voltage. The device uses a signal isolation circuit to receive a switch-controlling voltage of a motor driver and outputs a logic voltage. When a signal processing module receives the logic voltage from the signal isolation circuit, the signal processing module starts a counter and determines whether a rising or falling edge is present in the logic voltage. When determining that a first rising edge, a first falling edge, and a second rising edge are respectively present in the logic voltage, the signal processing module respectively stores a value of the counter as a first counter value, a second counter value, and a third counter value, and proceeds to calculate a voltage duty cycle of a motor-switching period based on the counter values. The present invention calculates the voltage duty cycle with improved accuracy.