【作者】 李坤全；

【导师】 方跃法；

【作者基本信息】 北京交通大学 ， 载运工具运用工程， 2008， 博士

【摘要】 基于并联机构的多维减振平台系统是多维减振领域里的新理念,新突破,在减振领域有着重要的应用前景和开发价值。鉴于并联机构具有结构简单,机型紧凑,精确度高,易于控制等特点,本文提出采用6-RSS并联机构作为六维减振平台的主体机构,来实现低频大幅多维的主动减振,对与系统相关的各项关键技术进行了研究。具体内容如下:利用牛顿-欧拉法建立六维减振平台主体机构6-RSS并联机构的动力学模型,由于充分考虑了动平台惯性,支腿惯性等因素,保证了模型的精确程度,通过数值仿真验证了以6-RSS并联机构为减振平台主体减振机构的动力学模型的正确性和精确性。由于六维减振平台是复杂的机电系统,机构参数和控制参数之间存在着耦合现象,为提高减振平台系统的性能指标,从控制与机构同步优化的观点出发,对以6-RSS并联机器人为主体机构的减振平台的参数进行优化设计,通过计算仿真说明六维减振平台的控制和主体机构同步优化的有效性。考虑到时滞对控制精度的影响,建立了减振平台主体机构静平台中心点的测量运动学模型,此模型充分考虑到测量仪器的误差和未知扰动等因素对系统的影响。之后采用卡尔曼滤波算法,对静平台中心点的位姿进行重新估计,并同时求得该点的速度和加速度。并通过数据仿真,从不同方面说明了该模型的有效性和合理性。最后对静平台中心点的位姿提前一步预测。在六维减振平台主体机构的关节空间构造了强鲁棒性的自抗扰控制器,利用遗传算法对参数进行整定,给出了其稳定性的必要条件,并对该控制器良好的磨擦扰动补偿能力进行了仿真证明。在此基础上,提出了复合控制的策略实现以6-RSS并联机器人为六维减振平台主体机构的主动减振控制,数值仿真结果说明该方法可以有效的抑制振动对减振平台定位精度的影响。更多还原

【Abstract】 Multi-dimensional vibration absorber based on the parallel mechanism is the new idea and the new breakthrough in the multi-dimensional vibration domain,has the important application prospect and the development value.A 6-RSS parallel mechanism is used as the main mechanism of six-dimension vibration absorber bemuse of its advantage on simple structure,the compact type,the high precision, easy-to-control and so on.This dissertation studies the application of the 6-RSS mechanism on active control of large amplitude low frequency multi-dimensional vibration.And the key technology of the vibration absorber system is studied carefully. The main research works can be described as follows.The dynamics model of the main mechanism of six dimension vibration absorber is achieved by Newton-Eular method.In order to ensure the accuracy of the model,the moving platform inertial,branched-chain inertia and other factors are considered deeply. Through the numerical simulation,the correctness and the accuracy of the dynamic model of the main mechanism are verified.As the six dimension vibration absorber is a complex mechanical and electrical systems,between the structure parameter and the controlled variable,the coupling phenomenon is existence.To enhance the performance of the vibration absorber,the parameters of the vibration absorber system are designed by the integrated optimal design of structure and control system.By simulation,the validity of this method is proved.Considering the effect of the time delay of the system,the measurement kinematical model of the base platform center is built to obtain exact states values of the center involves displacement,velocity,acceleration based on kalman filter theory.The influence of measuring instrument error and unknown disturbance to the system is considered fully in the model.The effective and the rationality of the model are analyzed from different aspects by simulation.Finally,the pose of the base platform center is predicted ahead of time.A robust auto-disturbance rejection controller in linkspace is developed to accomplish the high precision vibration control of the six dimension vibration absorber. Genetic algorithm is used for setting the controller parameters,a necessary condition of the controller stability is given,and the good compensation capability of the controller for friction disturbance is proved by simulated.This paper proposed compound control strategy to realize the active vibration isolation of six dimension vibration absorber.The numerical simulation results showed this method may effective suppress the influence of the vibration to moving platform pointing accuracy.更多还原