Enhancement the Maneuverability of Tele-Hydraulic System Using Fuzzy Friction Compensator

One degree of freedom (DOF) tele-hydraulic manipulation using force reflecting bilateral control will be investigated. The primary objective in the development of a simple one DOF experimental rig was to allow the investigation of different tele-control strategies prior to their implementation on the eight DOF tele-hydraulic excavator system. Because of the friction nonlinearity characteristic in hydraulic system, high steady state error and overshoot have occurred in the position response as a typical imperfect implementation of associated control dynamic. In this situation, there is a necessity to be able to effectively utilizing the intelligent friction compensated controller. This fuzzy compensator combined with fuzzy controller will be implemented to enhance the maneuverability performance. Experiments were carried out and the experimental results illustrated that the above compensated intelligent framework can improve the bilateral performance

A Compensation Approach of Backlash Nonlinearity in Dual-Motor Driving Servo System

Aiming at the control problem of dual-motor driving servo system with backlash nonlinearity, we proposed the model of system linear part. We used describing function methods to analyze backlash nonlinearity characteristic. The simulation experiments of nonlinear system with backlash were carried out. The results of simulation show that system represents residual self-oscillation with step response, nonstationarity with low speed tracking and error abrupt change produced by sinusoidal tracking reversing. In the end, we used compensation control strategy to weaken the impact of backlash nonlinearity on dual-motor driving servo system. Finally the simulation illustrates the effectiveness of the proposed compensation control strategy.

Nonlinearity Compensation for Thermocouple Vacuum Gauge Using Particle Swarm Optimized Least Squares Support Vector Machine

A method for compensating nonlinear characteristic of thermocouple vacuum gauge is proposed. Least squares support vector machine (LS-SVM) is adopt as compensation model, of which parameters are optimized using particle swarm optimization (PSO) algorithm. Experimental results using data obtained on-site show that the proposed approach effectively compensates the nonlinearity characteristic, and the accuracy of this method is higher than those obtained by SVM model.