Research On System Identification And Experimental Analysis Of Electro-hydraulic Proportional Pump-controlled Motor System

With the rapid development of the electro-hydraulic proportional control technology, it isused as the interface between the microelectronics technology and hydraulic technology. Thetechnology further promotes the expanding application of the pump-controlled motor system.In order to make the hydraulic system satisfy the higher demandof the system performance onproduction process, the designers must improve the response characteristics of the hydraulicsystem, working reliability, and the precise model of system. As the precise model is the basisof further improving and perfecting thesystem design. This paper identified electro-hydraulicproportional pump-controlled motor system using Matlab software, applying ARX andARMAX model identification methods. The control strategy of the system has carried on. Thesimulation analysis was made in allusion to the system. The main works are as following(1) The development and current situation of electro-hydraulic pr-operational controltechnology and system identification theory are briefly overviewed. So is the systemidentification theory. The importance of pump-controlled motor system modeling and thenecessity of identification modeling summarized. And the experiment table andpump-controlled motor modules briefly introduced in the paper.(2) According to the physical laws of the pump-controlled motor system, modules havebeen conducted on the basis of the theoretical modeling. That builds up a solid foundation toobtain the transfer function of the system and provide prior knowledge for the identificationmodeling.(3) The experiment reasonably designed.With the Matlab system identification toolboxfunctions, data.that is required by the identification can be collected. And the processobservation data is analyzed successfully. ARX and ARMAX model are identified by usingthe least square method and the extended least-square. And make residual correlation analysisand verification on the identified models. By comparing the identified models which arebased on the two kinds of model identification methods, the satisfying system model areultimately obtained.(4) In accordance with the system model by experimental identification, respectively using ramp, step and sine signals as simulation input signals, system simulation analysis wascarried out respectively aiming at the static, dynamic and following response of the system.According to the result of the simulation analysis the system response time, overshooting thesteady-state error and following performance are all improved significantly by means ofapplying PID control strategy. And they can satisfy the performance requirements of thesystem.System identification providing a new modeling method, which isn’t necessary tounderstand deeply for the system. And it merely needs to design a experiment. However,containing the information needed by system identification, obtaining the needed model arenecessary in the experiment. This paper carries out modeling and simulation analysis on theelectro-hydraulic proportional pump-controlled motor system with making full use of thepowerful function of the system identification toolbox of Matlab and Simulink modules. Itwill provide certain reference significance for the subsequent pump motor control systemdesign and control strategy analysis.