液压驱动Stewart平台的输出力控制研究

发布时间：2018-06-10 18:00

本文选题：并联机构 + 力控制　；参考：《燕山大学》2011年硕士论文

【摘要】：六自由度并联机构与串联机构相比,具有刚度大,结构稳定、承载能力强和控制精度高等一系列突出优点,从而被应用到了工业生产、航空航天、科学实验等各个领域。但目前对于其控制,大多是运动控制,将输出力而不是位姿直接进行控制的研究相对较少。随着六自由度并联机构应用的日益广泛以及机构自身的强耦合性,因此有必要对输出力进行智能控制。本文在分析了6-SPS并联机构力学模型和平台单自由度输出力控制方法以及有限元模拟的基础上,研究了模糊PID控制策略在并联机构力控制中较传统PID控制的优越性等问题。具体内容如下: 通过对力学模型的理论研究,推导出了六自由度并联机构的输出力公式,分析了输出力的影响因素,并给出了Stewart平台单缸力求解的算例。分析了平台单自由度输出力控制方法。以SolidWorks为工具,建立了Stewart平台机构的三维实体模型,利用COSMOSWorks对单个液压缸装配体和机构整体进行了有限元分析,得到应力、位移和应变云图,校验了危险截面的安全系数,最后对机构整体进行了振动频率的有限元分析。设计了适合本文的模糊PID控制器,调定了各个参数。建立了单缸力控制系统数学模型,并推导出系统的传递函数,给出控制框图。建立了单缸力控制系统和平台单自由度输出力控制系统的仿真模型,利用MATLAB/Simulink为仿真工具,对模糊PID控制和传统PID控制在单缸力控制和单自由度输出力控制中进行了对比仿真研究,并分析了液压缸泄漏、外界干扰和平台装配误差等因素对力控制的影响。用AMESim/MATLAB联合仿真的方法,从另外一个角度,也更精确的对模糊PID控制器的控制效果进行了仿真分析。
[Abstract]:Compared with the series mechanism , the six - degree - of - freedom parallel mechanism has a series of outstanding advantages such as large rigidity , stable structure , strong bearing capacity , high control precision and the like , thus being applied to various fields such as industrial production , aerospace , scientific experiments and the like .

Based on the analysis of the mechanical model of 6 - SPS parallel mechanism and the single - degree - of - freedom output force control method of the platform and the finite element simulation , the superiority of the fuzzy PID control strategy to the traditional PID control in parallel mechanism force control is studied .

By studying the theory of the mechanical model , the output force formula of the six - degree - of - freedom parallel mechanism is derived , the influencing factors of the output force are analyzed , and an example of the single - cylinder effort solution of the Stewart platform is given . The control method of single - degree - of - freedom output force of the platform is analyzed .

In this paper , a three - dimensional solid model of Stewart platform mechanism was established by using the software as a tool . By using COSMOStool , finite element analysis was carried out on the whole assembly and mechanism of single hydraulic cylinder , and the safety factor of dangerous section was verified . Finally , finite element analysis of vibration frequency was carried out on the whole mechanism .

This paper designs a fuzzy PID controller which is suitable for this paper . The mathematical model of single cylinder force control system is set up and the transfer function of the system is deduced . The simulation model of single cylinder force control system and single degree of freedom output force control system is deduced .
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH137

【引证文献】