微位移控制液压系统建模与模型辨识  

Modeling and Model Identification of Micro-position-control Hydraulic System

作　　者：彭雄斌[1] 龚国芳[1] 廖湘平[1] 吴伟强[1] 汪慧[1] 娄海洋 

机构地区：[1]浙江大学流体动力与机电系统国家重点实验室,杭州310027

出　　处：《机械工程学报》2017年第22期206-211,共6页Journal of Mechanical Engineering

基　　金：国家重点基础研究发展计划(973计划;2013CB035400);国家高技术研究发展计划(863计划;2012AA041803)资助项目

摘　　要：为实现微米级别位移控制,采用伺服驱动器、交流永磁同步电动机和位移放大液压缸代替传统伺服阀和泵源,利用位移放大液压缸与执行液压缸的有效面积比,对执行液压缸进行精确定位。针对其液压系统进行数学建模,讨论液压油弹性模量、油液黏度、蓄能器压力与体积等变量对系统动态性能的影响。建立微位移控制系统AMEsim仿真模型,仿真结果表明:液压油弹性模量越大,系统响应越快;油液黏度越大,系统响应越慢;蓄能器压力与体积对系统响应影响微小,仿真结果与数学模型预测相符。设计试验台并在试验台进行液压系统开环扫频特性试验,使用Matlab辨识工具箱对系统试验数据进行模型辨识,辨识结果表明:二阶系统与试验数据的吻合度较高,与数学模型预测相符。基于辨识模型设计的PD控制器在微位移控制综合平台上得到了应用,位置控制偏差范围为-2~1.7μm。A micro-position-control hydraulic system（MHS） is proposed. This system utilized a servo motor and a hydraulic amplifying cylinder to replace hydraulic pump and servo valves. Mathematical model of MHS is derived and then influences on system open-loop behavior of oil modulus bulk, oil viscosity, accumulator pressure and volume are discussed. Relevant simulations are carried out under AMEsim environment, and the results show that large oil modulus bulk and small oil viscosity lead to fast open-loop response, while accumulator pressure and volume hardly influenced system open-loop behavior, which shows a good correlation with the mathematical model. A MHS test-rig is designed to verify the mathematical model. Open-loop frequency sweep experiment is carried out and test result is analyzed using Matlab system identification tool box. The identification results show that MHS performed a second order behavior with a resonance frequency of 46.5 Hz and a damping ratio of 0.303, which also reveals a good coincidence with the mathematical model. A PD controller based on identification results is adopted on a comprehensive test-rig with three MHSs, and the displacement bias ranges from –2 μm to 1.7 μm.

关 键 词：微位移控制 液压系统 建模 模型辨识 位置控制 

分 类 号：TH137[机械工程—机械制造及自动化]