Font Size: a A A

Research On Identification&Robust Control For Rolling Mill HAGC System

Posted on:2014-10-16Degree:DoctorType:Dissertation
Country:ChinaCandidate:X B ZhuFull Text:PDF
GTID:1261330425456708Subject:Mechanical design and theory
Abstract/Summary:PDF Full Text Request
Hydraulic servo systems are the important subsystems for the industrial, military andaerospace manufacturing. The static and dynamic characteristics of hydraulic servo systemsaffect the equipment performance directly. The structural dynamics, load disturbance andparameter changes of hydraulic servo systems cannot be ignored, with the increasingrequirements of quick response, output power density and motion precision. All of these posedtremendous challenges on the structure design and motion control of hydraulic servo system. Inorder to fulfill the urgent requirements of state key scientific research and engineering projects,the modeling and robust identification of hydraulic servo system, design of robust iterativelearning control and realization of principle prototype are studied in this dissertation. Throughthe characteristics analysis and controller synthesis, the performance of hydraulic servo system isimproved to meet the increasingly stringent performance requirements.In this thesis, the key issues of dynamic modeling and robust control for the hydraulic servosystem are studied. The parameterized mathematical model of hydraulic servo system isestablished by the combination method of theoretical analysis, simulation and experimentaltesting. The design of the controllers takes into account several aspects of the system’s dynamicsare completed. The proposed optimal approach is validated by the component level experimentalmeasurement. On the basis of analysis of the hydraulic servo system structures and systemcharacteristics,the mechanism model of the hydraulic servo system is derived. The two-stepnonlinear robust identification method based on Hardy space is proposed for the uncertainties ofthe system. The feasible parameter set of model parameters is obtained. The system model withparameter uncertainty set is established, to ensure that the real system falls on the model set. Inorder to achieve high precision and high efficiency motion, a smooth trajectory planning methodbased on ramp sinusoid functions, which can take the rapidity and smoothness of movement intoaccount.A feedback-feedforward form of iterative learning algorithms is introduced for the repetitivework space of hydraulic servo system. Iterative learning control strategy based on the impulseresponse matrix is designed to reflect the dynamic characteristics. According to the error of thesystem output to achieve the control signal, and refresh to iterative learning feed-forward order.Based on the quantitative feedback theory, the robust position controller for a hydraulic servosystem is studied, which considering model uncertain, stability and suppress disturbance ofmodel.Iterative learning control (ILC) design method for hydraulic servo system is discussed. Arobust ILC design method based H_∞method on is presented, and solvability of the method isanalyzed, the necessary and sufficient conditions of error convergence are derived. The robustILC method not only transformed iterative learning controller synthesis into most (sub) optimalcontroller design, but also deal with the uncertainties by selecting the appropriate weightfunction. The robust ILC method can be solved by the μ synthesis methods to maximize thelearning performance. The nominal ILC and the robustness ILC are design and performed in the experiment. The two ILC experimental results are compared, and the effectiveness of theproposed method is verified.The research results are applied to a hydraulic automatic gauge control (HAGC) systemsuccessfully. The hardware and software system of HAGC test platform are designed andimplemented. The identification experiments and control experiments are completed in the testplatform. The proposed methods can be used to guide the controller design for HAGC.
Keywords/Search Tags:Rolling mill Hydraulic automatic gauge control, Robust identification, Iterativelearning, Robust control, controller
PDF Full Text Request
Related items