Research On The Friction Compensation Of The Direct Drive Volume Control Electro-hydraulic Servo System

The Direct Drive Volume Control Electro-hydraulic Servo System is a technological revolution in the Hydraulic System.The new DDVC Electro-hydraulic Servo System direct drive quantitative pump rotation and then drive the load movement through the completion of the motor control.The system has multiple merits of flexible motor control and large system output,and the new DDVC Electro-hydraulic Servo System has no throttling energy loss.It has high energy efficiency and can replace the hydraulic servo system.It has been widely used in the ocean and aviation field.DDVC Electro-hydraulic Servo System is usually used in high-precision occasions.It has high requirements on the performance of DDVC Electro-hydraulic Servo System,especially the low speed performance of the system.Load friction is an important factor affecting low speed performance and accuracy of the system.Considering technology and implementability,the impact has been greatly restricted through changing the object technology to weaken the friction in the DDVC Electro-hydraulic Servo System.Therefore,adding a controller to the system for friction compensation has very good research and development prospect theoretical depth significance.In this paper,the mathematical model of DDVC Electro-hydraulic Servo System is established.The DDVC Electro-hydraulic Servo System is divided into two parts: motor and hydraulic.The mathematical models of these two parts are deduced and their transfer functions are obtained.The simulation model of hydraulic drive in DDVC Electro-hydraulic Servo System was completed by AMESim simulation software.The establishment of simulation model of AC motor in Matlab simulation software was completed.The two parts were integrated to obtain the DDVC Electro-hydraulic Servo System Simulation model.This paper simulates the DDVC Electro-hydraulic Servo System under ideal conditions,and obtains the tracking response curve of the system to the input in an ideal state,and the system is in a stable state.In this paper,Stribeck friction model and Leuven friction model were selected to describe the friction characteristics respectively,and the two friction models were respectively packaged into sub-modules,which were added into the simulation of DDVC Electro-hydraulic Servo System.This paper analyzes the influence of the friction part on the output characteristics of the DDVC Electro-hydraulic Servo System.This paper designes respectively the improved controller of Leuven model,anti-saturation controller and PID compensation controller by analyzing the interference caused by load friction on the DDVC Electro-hydraulic Servo System.These controllers are added to the DDVC Electro-hydraulic Servo System simulation model,and the simulation model of the DDVC Electro-hydraulic Servo System with friction compensation controller is established.After the simulation analysis,the system is stable and the tracking signal is good when adding the improved controller based on Leuven model and anti-saturation controller,and the friction compensation research of DDVC Electro-hydraulic Servo System is completed.