| Hydraulic synchronous control is widely used in some situation s for heavy and large equipment in industry. It takes synchronization motion of multiple ac tuators to drive the load with increasing demand for capacity of load, because only one actuator can’t meet the requirement. If synchronism isn’t well between actuators, the stability and working efficiency of equipment will be reduced, even lead damage to equipment. Therefore, it’s necessary to study the problem of synchronization between multiple actuators for industrial applications.In this article, through searching and reading lots of related references, nonlinear mathematical model of single hydraulic branch is established according to the structure and principle of electro-hydraulic servo position system. Then use Lab VIEW to simulate the mathematical model. With the simulation results, this article uses compound fuzzy control method which based on fuzzy and PID control for correction of single cylinder system.Design fuzzy PID linear hybrid controller and fuzzy self-tuning PID controller based on mathematical model. Use Lab VIEW to design two kinds of controller and compare simulation results with PID controller. Compared performance of three kinds of controller in different condition, choose fuzzy self-tuning PID controller as the controller of single cylinder system finally. After completing of the design of single cylinder controller, synchronization is studied. Analysis the results of master-slave synchronization mode and same synchronization mode. Then use a cross coupled mode based on improved same synchronization mode, put a PID controller in the feedback channel. For step signal, the maximum sync hronization deviation is reduced, and can quickly converge to the steady state. For 1Hz and 2Hz sine signal, synchronous deviation fluctuation can be controlled within the scope of 0.008 mm. A better performance is obtained.Experimental research is performed based on double cylinder electro-hydraulic position synchronization system. Experiments for single cylinder system are studied firstly. For 10 mm step signal, response time of PID control and fuzzy self-tuning PID control is both 0.1s. Steady state error of fuzzy self-tuning PID control is smaller. Performance of fuzzy self-tuning PID control is better with variable working condition. Then fuzzy self-tuning PID controller is applied to the double cylinder system. Results of experiment show that, synchroni zation deviation of master-slave mode is largest, and cross coupled mode perform better than same mode. For 0.5Hz to 2Hz sine signal, fluctuation range of synchronous deviation for cross coupled mode is always kept in the scope of 0.15 mm. Finally experimen tal research is performed for cross coupled mode in the condition of variable working condition. The results showed that cross coupled mode with using fuzzy self-tuning PID control for single cylinder improves the synchronization accuracy and performance of system. A desired result is achieved. |
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