發(fā)布時間：2018-04-03 08:43

  本文選題：摩擦加載　切入點：摩擦系數(shù)波動　出處：《哈爾濱工業(yè)大學》2016年碩士論文

【摘要】：本文所研究的電液伺服摩擦加載技術可以用在電液伺服負載力波形模擬以及碰撞加速度波形模擬等研究領域,具體比如航天返回艙的碰撞模擬,負載模擬器、臺車碰撞模擬器等等。傳統(tǒng)液壓或電動負載模擬器是用驅動裝置通過剛性連接直接給承載裝置施加負載力,由于位置和力的耦合而產(chǎn)生多余力,多余力得不到完全消除導致其很難提高頻寬和加載精度;傳統(tǒng)意義上的碰撞模擬器,也就是對加速度波形的模擬,由于有需要超大流量閥和頻寬低等問題,也很難達到理想的波形復現(xiàn)。本文所研究的摩擦力加載,中間環(huán)節(jié)用摩擦副代替了剛性連接,沒有了力和位置的耦合,也因此沒有了多余力問題,理論上可以擁有更優(yōu)的加載性能。電液伺服摩擦加載技術是一個新的技術,這種技術也有只能進行與運動方向相反的力加載以及摩擦系數(shù)波動較大等缺點。本文首先對摩擦環(huán)節(jié)進行仿真研究,然后進行摩擦力加載系統(tǒng)線性、非線性模型數(shù)學建模,從而可以對系統(tǒng)關鍵參數(shù)展開線性分析,并據(jù)此綜合液壓系統(tǒng)伺服閥流量和機械系統(tǒng)的支撐架剛度進行綜合交互設計。根據(jù)本文所設計的加載原理結合理論分析,進一步對摩擦力加載系統(tǒng)試驗臺進行設計與搭建。搭建好試驗臺,首先對摩擦力加載系統(tǒng)的子系統(tǒng)——夾緊力系統(tǒng)的控制特性展開研究。針對相位滯后的問題,分別提出用反饋——前饋綜合控制器和提高機械剛度的軟、硬件解決方法,并在實驗中對相位滯后問題得到一定程度的改善。結合理論研究,進行實驗驗證和分析。首先對本系統(tǒng)的摩擦特性展開實驗研究,分析各種摩擦材料的摩擦特性,并根據(jù)實驗結果選擇進一步實驗所采用的摩擦材料。從夾緊力系統(tǒng)開始研究,初步掌握加載系統(tǒng)控制特性,最后對摩擦加載系統(tǒng)展開實驗分析。摩擦系數(shù)的波動在摩擦力控制時體現(xiàn)出來,普通控制器,比如PID控制器很難適應這種波動。這是一種系統(tǒng)不確定性,據(jù)此設計了魯棒控制器,分別用μ綜合魯棒控制器和H∞魯棒控制器對系統(tǒng)進行控制分析,最后對實際系統(tǒng)進行系統(tǒng)辨識,根據(jù)辨識出來的傳遞函數(shù)設計魯棒控制器,并進行了相關的實驗分析。
[Abstract]:The electro-hydraulic servo friction loading technology studied in this paper can be used in the research fields of electro-hydraulic servo load waveform simulation and impact acceleration waveform simulation, such as the impact simulation of space return cabin, load simulator, etc.Car collision simulator and so on.The traditional hydraulic or electric load simulator uses the driving device to directly apply load force to the bearing device through rigid connection, which produces multiple Yu Li due to the coupling of position and force.It is very difficult to improve the bandwidth and loading accuracy due to the failure of eliminating the multiple Yu Li completely. The traditional impact simulator, that is, the simulation of acceleration waveforms, has some problems such as the need for super-large flow valves and low bandwidth.It is also difficult to achieve ideal waveform reproduction.In this paper friction loading is studied in which the friction pair is used to replace the rigid connection and there is no coupling between the force and the position. Therefore there is no more Yu Li problem and the better loading performance can be obtained theoretically.The electro-hydraulic servo friction loading technique is a new technique, which can only carry out force loading opposite to the direction of motion, and the friction coefficient fluctuates greatly.In this paper, first of all, the friction link is simulated, and then the linear and nonlinear models of friction loading system are established, so that the key parameters of the system can be analyzed linearly.According to this, the hydraulic servo valve flow and the support frame stiffness of the mechanical system are integrated and interactively designed.According to the loading principle designed in this paper and theoretical analysis, the friction loading system test-bed is further designed and built.The control characteristics of the clamping force system, the subsystem of the friction loading system, are studied in this paper.Aiming at the problem of phase lag, the software and hardware solutions to improve the mechanical stiffness by using feedback feedforward integrated controller are put forward, and the phase lag problem is improved to a certain extent in the experiment.Combined with theoretical research, experimental verification and analysis are carried out.Firstly, the friction characteristics of the system are studied experimentally, the friction characteristics of various friction materials are analyzed, and the friction materials used in further experiments are selected according to the experimental results.Starting with the study of clamping force system, the control characteristics of the loading system are preliminarily grasped. Finally, the experimental analysis of the friction loading system is carried out.The fluctuation of friction coefficient is reflected in friction force control, and it is difficult for ordinary controller, such as PID controller, to adapt to the fluctuation.This is a kind of system uncertainty. According to this, a robust controller is designed, and the control analysis of the system is carried out by using 渭 synthesis robust controller and H 鈭，

本文編號：1704461