The Research on Electro-hydraulic Servo Sliding Mode Control Based on Differential Evolution

摘要

In order to improve the convergence rate and control accuracy of the electro-hydraulic servo control system, differential evolution optimization and genetic optimization are used to optimize the sliding mode factor and convergence rate in the sliding mode control. The input-output error and control input are taken as optimization indexes, and a penalty term is added when the error is greater than zero to ensure that the system will not produce large overshoot. K-type observer and saturation function are used for signal observation and jitter reduction. The structure of simulation program is designed with three parts of optimization algorithm module, sliding mode control module and evaluation function. The individual of algorithm has 30 chromosomes, and the system is iterated 50 times in Matlab/Simulink. The simulation results show that the two optimization algorithms can converge to get the optimal solution of the model, but the convergence speed of differential evolution algorithm is faster; the tracking effect after optimization is good, and the error curve changes in the range of ±0.00015 in the steady state, achieving a high control accuracy. The optimized system has faster convergence speed, higher position tracking accuracy and evaluation index as low as 2.15, which has better engineering application value.