Hydraylic Drive System Design And Control Method Study Of Structural Loading System

With the frequent occurrence of earthquakes and other natural disasters, the loss oflife and property is being more and more serious and people come to realize theimportance of building structure using reasonable anti-seismic design. Currently,researchers usually verify the rationality of structural design and the correctness ofmechanical analysis through structural test using structural loading test system which isthe most indispensable key equipment. To ensure the structural test conducted smoothly,the force control method for loading test system must be studied.The general situation about structural loading test system is reviewed in this paperat first, and the research status as well as the key issues of force control strategy aresummarized, and then the main contents of this topic is presented. Afterwards the paperintroduces the constitution and the operating principle of60000kN structural loadingtest system, and the hydraulic drive system as well as the incomplete static pressuresupporting are designed based on system demands which laid the foundation of systemmodeling and simulation and the study of force control method.In the study of force control in structural loading system, this thesis propose themultiple-DOF structural loading system control method based on the idea of innerposition loop based explicit force control. And then, the structure of control system andforce controller are presented. The pose composition/decomposition model has beenbuilt and the geometric decoupling has been done. Force balance controller is proposedto reduce internal force coupling. United simulation is conducted to prove the rationalityof force control method.Last but not least, model reference adaptive control method is proposed in thispaper based on the special characteristic of rubber bearings which is that stiffness anddamping parameters will change during dynamic loading process. According to thesecond discrimination law of Lyapunov stability theorem, the state equation of systemgeneralized error and the adaptive control law are derived, hence the adaptive PIDcontroller is completed. Contrast simulation of normal PID control and adaptive PIDcontrol are conducted in single channel system and multiple-DOF system respectivelyto prove the adaptive controller is able to adjust its control parameters according to thechanges of specimen’s parameters and also has a better control performance.