液体静压轴承控制系统的动态性能研究

Dynamic performance of hydrostatic bearing control system

目前,针对磨床液体静压轴承控制系统进行动态特性分析时,多限于采用经典控制论的方法,为此,对液体静压轴承控制系统具有的非线性(特性)、多输入多输出(特性)、时变特性等进行了仿真与实验研究。首先,分析了液体静压轴承系统的工作原理,并采用键合图理论建立了液体静压轴承控制系统键合图模型,推导出了系统的状态空间方程;然后,运用仿真软件MATLAB/Simulink对轴承控制系统进行了仿真,分析了其时域响应特性;最后,搭建了液体静压轴承试验平台,对该液体薄膜反馈静压轴承系统的动态性能进行了验证,并将其结果与仿真结果进行了对比分析。研究结果表明:该液体薄膜反馈静压轴承系统具有良好的静态性能和动态特性,静态误差减小5%,动态特性指标超调量为12%,响应时间为10 ms,峰值时间为6 ms左右,综合指标均得到了改善,满足了期望的设计技术参数要求;解决了该液体静压轴承静态精度较低,以及动态特性易受外界载荷扰动的问题。

In orderto solve the problem that the analysis of the dynamic characteristics of the control system of hydrostatic bearing of grinding machine was limited to the classical cybernetic method,the nonlinear,multi-input,multi-output and time-varying characteristics of the control system of hydrostatic bearing was studied by simulation and experiment.Firstly,the working principle of hydrostatic bearing system was analyzed,and the bond graph model of hydrostatic bearing control system was established by using bond graph theory,and the state space equation of the system was deduced.Then,the system was simulated by MATLAB/Simulink,and the response characteristics in time domain were analyzed.Finally,the dynamic performance of the liquid film feedback hydrostatic bearing system was verified on the experimental verification platform and compared with the simulation results.The results show that the designed liquid film feedback hydrostatic bearing system has good static performance and dynamic characteristics,the static error is reduced by 5%,the overshoot of dynamic characteristics index is 12%,the response time is 10 ms,and the peak time is about 6 ms.The comprehensive indexes are improved and meet the requirements of the desired design technical parameters.The problems of low static accuracy of the hydrostatic bearing andits dynamic characteristics being easily disturbed by external loads are solved.