Dynamic Erroranalysis And Compensation Technology Research Of Linear Variable Differential Transformer

Sensors are the key components in electro-hydraulic system, the accuracy of whichhave an important impact to the control of flow，pressure and other parameters, therebythe compensation of sensor’s dynamic characteristics is significant to improve theperformance of electro-hydraulic system. In order to correct differential transformerdisplacement sensor’s dynamic error and improve its dynamic characteristics, this paperdose deep study on the dynamic error during dynamic measurement, and puts forward atarget of “fraction of dynamic error” to analyse it quantificationally, using this targetto verify the effectiveness of zero-pole redisposing based digital filter on LVDT.After brief introduction of LVDT’s working principle, performance parameters andmathematical model, this paper leads to dynamic error and point out the existence of itin the practical application. Considering the affecting factors of dynamic error, thispaper devide it into4categories according to its origins, and foucs on the study of itcaused by response time, overshoot and bandwidth. For quantitative analysis ofdynamic error, the formula for calculating fraction of dynamic error is deducted in thispaper. After introduction of the three commonly used method for dynamic errorcorrection, their disadvantages are discussed. The zero-pole redisposing based digitalfilter’s advantages are introduced, whick is choosed to be studied.Considering the zero and pole decide system’s dynamic characteristics, theformulas are deducted, the relation curves are drawn, effective intervals are given fordynamic error correction through these formulas and curves.Finally, this paper uses valve used LVDT as the object, calibrating its staticperformance and dynamic characteristics, compensating its dynamic characteristics withzero-pole redisposing based digital filter, and tested the effectiveness effectivenesscombined with the simulation.