Multi-objective Optimization On Performance Parameters Of LVDT Based On Genetic Algorithm

Linear Variable Differential Transformer which is shorted as LVDT in the following is widely used in Hydraulic industrial production.As a very important part of the eletro-hydraulic control system,the performance of LVDT has a great influence on the control of the parameters like the flow,the pressure of the whole system.This paper uses LVDT in the straight moving type servo proportional valves as the research subject.Firstly,its structure and working principle are introduced,and the input and output mathematical model of LVDT is established under the Biot-Savart law and the analysis of the equivalent circuit,which is based on the electromagnetic field theory.Then the paper analyzes the influence of the change of the main structure parameters such as LVDT primary coil?secondary coil and iron core to the sensitivity and nonlinear error in detail.To improve the output performance of the LVDT,gamultiobj function,which is based on genetic algorithm,is proposed in this paper to solve multi-objective optimization problems of parameter optimization of LVDT.First,multi-objective optimization problem and the realization of the algorithm are briefly introduced.With the mathematical model of the sensitivity and nonlinear error of LVDT as the objective function and determine the constraint relation,then optimization program is done from numerical simulation software.Finally,some set of optimal solutions is got.By comparing three groups of optimal solutions and simulation value of the initial structural,the results show that static characteristic of the LVDT with new structure have greatly improved.Finally,LVDT static characteristic experiment testing system is builded and virtually static characteristic index of LVDT is got from it.By comparing the experimental results and simulation results shows that the established input and output mathematical model of the LVDT is reasonable and the simulation results can reflect the static characteristics of LVDT.Meanwhile,the use of multi-objective optimization genetic algorithm to improve the performance index of LVDT is feasible.