Papers by Keyword: Electro-Hydraulic Servo

Abstract: Loading system of pumping unit simulates the working condition of pumping unit. It can repeat all kind of the real force and motion on pumping unit and detect the quality of pumping unit. Through analyzing the indicator diagram of pumping unit, we design a elecro-hydraulic servo loading system of pumping unit which uses the method of displacement and force feedback control. Meeting the load requirement simulated it with AMESim software.

Abstract: Aiming at the overshoot problem of electro-hydraulic position servo system used in the process of railway rescue crane hydraulic automatic leveling, and based on its characteristics such as big output power, high control accuracy, quick response speed, et al, this paper established the linear mathematical model of railway rescue crane electro-hydraulic automatic leveling system, besides, the fractional order PID control method was proposed based on the oustaloup digital filter algorithm and the working principle of fractional order PID control method was given, and then the fractional order PID controller was designed. In order to verify the effectiveness of the proposed control strategy, the MATLAB/Simulink simulation software was used. The simulation results show that the fractional order PID controller improved the speed of electro-hydraulic servo system unit step response and the capacity of resisting disturbance compared to traditional integer order PID controller, besides it can ensure the response without overshoot at the same time, so it meets the requirements for rapidity and no overshoot of railway rescue crane hydraulic automatic leveling system very well.

Abstract: The two-cylinder drive is one of many commonly used mechanical drive forms. Its synchronous control accuracy determines the movement accuracy of the working machinery. The paper established the mathematical model for the two-cylinder electro-hydraulic servo synchronous drive system, and revealed that the two-cylinder horizontal electro-hydraulic synchronous drive system has the cascade form of the linear system with the nonlinear system. Taking the band sawing machine and the broaching machine as the application object, the paper analyzed their compositions and synchronization CNC systems. Aiming at the dual-cylinder drive form for the broaching machine, the IPSO-PID synchronous controller of the two-cylinder system was designed. Through the digital simulation and actual testing, the results show that the IPSO-PID synchronous controller is faster in the tracking response speed and better in the synchronization performance than the conventional PID synchronization controller.

Abstract: The indoor road simulation test system test cycle is short, good reproducibility of the test results, confidentiality, etc., more and more attention in the vehicle industry. Analyzed by electro-hydraulic servo system of road simulation servo amplifier, electro-hydraulic servo valve, hydraulic cylinder and countertops and displacement transducer, The mathematical model of the system is established. The fuzzy model that comply with control law is designed. By unit step response simulation experiments, it is to be verified that the fuzzy control electro-hydraulic servo road simulation system is able to work better. It is a new attempt in roads simulation control strategy.

Abstract: Aiming at the cutting for various kinds of material, in order to solve the problems that the present large band saw equipment at home is poor in the synchronization of the sawing feed and is lack of the dedicated NC system, the paper introduces the electro-hydraulic servo drive and digital control technologies, researches the synchronous servo drive and cutting force feedback control technologies, and develops the sawing machine’s control system based on the above technologies. The NC system has been applied in the CNC band saw equipment of the large Portal style. The saw frame uses the structure driven synchronously by the dual hydraulic cylinders in order to guarantee the accuracy of the feed motion. The control system driven by the electro-hydraulic servo synchronization detects the implementation of a two cylinders and does the displacement feedback to achieve the movement synchronization on both ends of the portal frame using the synchronous control strategy. That ensures the movement accuracy for the CNC band saw equipment of the large Portal style and improves the cutting accuracy and efficiency of the equipment.

Abstract: To eliminate the errors of cylinders’ dynamic output positions of master side for the influence of random disturbance of slave side, master-slave position controller based on disturbance state observer optimal control and robust dynamic compensate PD feedback control algorithm is designed for electro-hydraulic servo tele-robot. A linear quadratic with disturbance observer and a dynamic robust compensator position controller is developed. Experimental results demonstrated the proposed algorithm is availability and showed that the designed controllers both improved position tracking precision for master-slave side and possessed good adaptive ability and robustness in existence of uncertain disturbance, enhanced the operational performance.

Abstract: The uncertainty of system parameters is not considered in traditional transfer function model of electro-hydraulic servo system, and then the accuracy of analysis is affected. Therefore the physical model of electro-hydraulic servo control system is established in simulation software AMESim platform. The system controller model is builded in the control simulation software Matlab/Simulink platform. The co-simulation interface technology is used to achieve joint simulation of electro-hydraulic servo control system.

Abstract: Electric-hydraulic servo system is a nonlinear and uncertain system with time-varying parameters and interference. The fuzzy PID control algorithm is used,which not only keep the flexible characteristic of fuzzy control algorithm but also inherit the traditional PID control algorithm advantages of high control precision. Research shows that fuzzy PID control has the character of fast response speed, rising fast, small lag, small overshoot, anti-interference, do not depend on the accurate model.

Abstract: The parameters uncertainty and external disturbance play a negative role to improve electro-hydraulic position servo system performance. The valve controlled cylinder system model is established, using the traditional PID control strategy and reaching law control strategy for simulating the system, respectively, the two methods have similar control effects in the ideal model, but considering the external disturbances, the index approaches sliding mode control law has better response speed and stability. Research shown that sliding mode control algorithm has an important role for improving the performance of hydraulic servo position control system.

Abstract: In this paper, an applied classic control theory is adopted for the dynamics analysis for the electro-hydraulic servo drive device in which lower-powered integrative base on Matlab. The concrete measures are carried out to improve the dynamics of the system.