Study On The Design And Control For Direct Driving Electro-hydraulic Actuator Of Control Valve

As an important role to control parameters of fluid in modern factories,the control valve is widely used in the industrial circle like petrochemical,energy,power station,aerospace,metallurgy,etc.With the acceleration of China's modernization and the automation process of industrial,more and more control valves which get the character of high performance will be demanded.The valve actuator,as the key component to output driving force,determines the performance of a control valve.The electro-hydraulic actuator meets the demand of industrial's development as its excellent performance to control,and gets a broad market prospect.Now most electro-hydraulic actuators of high performance are imported from the other countries,it's essential to develop the high-performance electro-hydraulic actuator which has independent intellectual property rights of ourselves'.This paper introduces a new kind of electro-hydraulic actuator and we have done the following research about it.Firstly,a new kind of electro-hydraulic actuator combined with DDVC was designed(here called "the direct driving electro-hydraulic actuator").Hydraulic system principle was drawn up,and the main components of the electro-hydraulic actuator were chosen according to the calculation and the realistic demand.A pump-control system with the compact structure was completed finally.Secondly,based on the function of the control system,we developed the electro-hydraulic actuator's controller with the core of STM32F103.The study of the controller realized the function of data acquisition,keyboard inputs,the LCD display,the servo motor's drive,etc.The design of hardware circuit was completed in the software of EDA,the main program and department programs was completed in the software of Keil,and we designed the upper computer with the function to communicate with the controller.Finally we combined the pump-control system and the controller and complete the design of the electro-hydraulic actuator.Thirdly,based on the structure and the parameters of the electro-hydraulic actuator,we established the mathematical model on the part of servo motor,pump control cylinder system,the sensor,etc.And we deduced the transfer function,aiming to establish the relationship among the input signal,the opening of the electro-hydraulic actuator,and the load.According to the MATLAB Bode diagram criterion,we could concluded that the stability margin is big and the system stability is good.Finally,we studied and developed the control strategy of the electro-hydraulic actuator.We used the flower pollination algorithm to optimize the parameters of PID controller and established the Simulink module of MATLAB aiming to study the dynamic characteristic of the system.The simulation results show that:compared with the Z-N method,the flower pollination algorithm could optimize the parameters of PID controller in a better way,the system's step response ability becomes stronger,the waveform tracking and anti-jamming performance becomes more excellent.That makes the electro-hydraulic actuator could be suitable for the control valve of high performance.