Research On Linear Drive System Based On Digital Hydraulic Transformers

Linear actuator is widely used in hydraulic transmission system,which has the advantages of high power and high power density,but it also has the disadvantages of high energy consumption,low efficiency and complex control,which restricts its further application and development.Hydraulic transformer is the key component of common pressure rail.It is a hot spot in the field of hydraulic transmission and control in the future to change the output pressure of the system by adjusting the ratio of voltage change.In this paper,a linear drive system based on digital hydraulic transformer is designed.The system applies the secondary regulation technology to the traditional hydraulic system,which can not only regulate the output pressure of the system without throttling loss,but also recover the potential energy and kinetic energy at the load end.The system is mainly composed of constant pressure source,digital hydraulic transformer and hydraulic actuator.When working,the hydraulic transformer adjusts the transformation ratio according to the load and outputs the corresponding pressure oil to drive the hydraulic actuator.In this paper,firstly,the different connection modes and working characteristics of the system are introduced,and the mathematical modeling of each component of the system is established.Then,according to the working principle of the system,a controller similar to automobile shift is designed by using fuzzy control.When the load changes,the controller can adjust the transformer’s pressure ratio according to the shift parameters to make the system output the corresponding pressure oil.The performance of the system is studied through the mathematical model,simulation model and experimental test.The physical model of the system is built in AMESim software,and the control model of the system is built in Simulink software for CO simulation to verify the feasibility of the system.Finally,a test platform is built to test the system.The working characteristics of the system under different working conditions are tested by changing the size of the load under the constant voltage source.The results show that the hydraulic transformer can not only drive the load movement,but also recover the energy at the load end,and the system output can adapt to the load changes well,which verifies the accuracy of the theoretical analysis.