Research On Servo Control System Of Remanufacturing Hydraulic Cylinder Test Bench

With the country's growing natural resource reserves and the ecological damage caused by the exploitation of resources,the country has begun to vigorously develop remanufacturing projects that can recycle waste products for reuse.Among them,remanufactured hydraulic cylinders are favored by more and more manufacturers because of the low price.Therefore,this paper mainly aims at some problems in the process of testing the performance index of the remanufactured hydraulic cylinder,especially in the minimum starting pressure(friction)testing project,which needs manual positioning and has low control precision.Thus we studied the servo control system for remanufacturing hydraulic cylinder test bench.First,in order to meet the requirements of performance testing,the technical requirements and performance indicators of the hydraulic system were established,the existing minimum starting pressure test was improved,the hydraulic test circuit was redesigned,and the static calculation was completed for the hydraulic system.Then based on fluid mechanics and other theories,the basic equations of the valve-controlled asymmetric hydraulic cylinder and the mathematical model of the hydraulic servo system are established,and the mathematical model 1s simplified.After quantifying the parameters based on the established mathematical model,the system was dynamically simulated using MATLAB/Simulink software,but the simulation results did not meet the requirements.Therefore,the ideal step response curve is obtained by PID control.But in the adaptive process of testing the PID control,the adaptability of PID control is found to be poor,which can not meet the requirement of changing the hydrauhc cylinder test frequently,so the better control method 1s sought.Further,a conventional fuzzy controller 1s designed based on the fuzzy control theory.After the simulation of conventional fuzzy control,the adaptability of the simulation curve was found to be better than that of PID,but there was a problem of static error and long response time.By analyzing the advantages and disadvantages of PID control and conventional fuzzy control,it is decided to adopt a adaptive fuzzy PID control method.A adaptive fuzzy PID controller is designed and the model 1s simulated.The simulation results show that the response curve eliminates the static error,and the response time 1s within the required range to meet the expected requirements.Finally,the design of the PLC electrical control system was completed.The hardware of the PLC electrical control system was designed in detail,and the PLC selection,I/O port assignment,and hardware wiring diagrams were completed.Then the software was designed,including the program flow chart and the preparation of the sequential function chart.This paper redesigns the hydraulic test circuit,establishes the mathematical model of the hydraulic servo system,simulates through PID control,conventional fuzzy control and fuzzy PID control,and designs the PLC electric control system.It meets the performance requirements of the hydraulic servo system,and can quickly and accurately locate the position to be detected,and effectively solve the problem of the poor adaptability of the system caused by the frequent replacement of the hydraulic cylinder.