全方向康复步行训练机器人的随机模型与控制

发布时间：2018-02-10 05:41

本文关键词： 全方向康复步行训练机器人随机参数自适应容错控制输出反馈控制　出处：《沈阳工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着高龄人口增多,脑神经系统疾病及运动神经系统疾病导致步行障碍患者逐年增加,由于医护资源的有限性,使下肢康复机器人得到了发展。康复机器人具有高度非线性和强耦合性,在跟踪医生指定训练轨迹时由于受到重心偏移、执行器故障、速度传感器测量的准确性、位移传感器测量信息的完整性等因素影响,很难获得精确的轨迹跟踪。为了提高下肢康复机器人的跟踪精度,本论文以一种全方向康复步行训练机器人为研究对象,基于随机控制理论研究轨迹跟踪问题,主要内容如下:通过将重心偏移引起的随机参数转化为随机扰动,并与随机理论相结合,得到了全方向康复步行训练机器人的随机模型;基于此模型设计了状态反馈控制器,使跟踪误差系统指数均方一致稳定,并通过调整控制器参数,使跟踪误差及其导数趋于零附近的任意小邻域内;数值仿真结果说明了状态反馈控制器可以使得全方向康复步行训练机器人精确跟踪预定的轨迹。将发生故障的执行器从随机模型的控制矩阵中进行分离,将其视为外部的有界扰动,并基于随机稳定性判据设计了一个自适应容错控制器;稳定性分析证明了通过这个控制器的作用,可以使得跟踪误差系统指数均方一致稳定,并通过控制器参数和自适应率参数的调整,可以使得跟踪误差和它的导数趋于零附近的任意小邻域内;仿真结果说明了基于随机模型设计的自适应容错控制器可以同时应对重心偏移和执行器故障。建立了描述不完整输出信息的数学模型,基于该模型进行了输出观测器的设计;基于速度观测器信息,设计了输出反馈控制器;稳定性分析证明了由输出观测误差、速度观测误差、轨迹跟踪误差组成的闭环系统是指数均方一致稳定的,并通过调整参数可以使这些误差和它的导数趋于零附近的任意小邻域内;数例仿真结果说明了输出观测器、速度观测器、输出反馈控制器的有效性。
[Abstract]:With the increase of the elderly population, the number of patients with walking disorders caused by brain and motor nervous system diseases has increased year by year. Due to the limited medical care resources, The rehabilitation robot has a high nonlinear and strong coupling, because of the deviation of the center of gravity, the fault of the actuator, the accuracy of the speed sensor measurement when tracking the training track specified by the doctor. In order to improve the tracking accuracy of the lower limb rehabilitation robot, a kind of omnidirectional rehabilitation walking robot is taken as the research object, because of the influence of such factors as the integrality of measurement information of displacement sensor, it is difficult to obtain accurate track tracking. The trajectory tracking problem is studied based on stochastic control theory. The main contents are as follows: by transforming the random parameters caused by barycenter deviation into random perturbation and combining with stochastic theory, the random model of omnidirectional rehabilitation walking robot is obtained. Based on this model, a state feedback controller is designed to make the tracking error system exponentially mean square uniformly stable, and by adjusting the controller parameters, the tracking error and its derivative tend to any small neighborhood near zero. The numerical simulation results show that the state feedback controller can accurately track the predetermined trajectory of the omnidirectional walking robot and separate the actuator from the control matrix of the stochastic model. An adaptive fault-tolerant controller is designed based on random stability criterion, which is regarded as an external bounded disturbance, and the stability analysis proves that the tracking error system can be exponentially uniformly stable by the use of the controller. By adjusting the parameters of the controller and the adaptive rate, the tracking error and its derivative tend to be within any small neighborhood near zero. The simulation results show that the adaptive fault-tolerant controller based on stochastic model can deal with both gravity center offset and actuator fault. A mathematical model describing incomplete output information is established and the output observer is designed based on the model. The output feedback controller is designed based on the information of the speed observer, and the stability analysis proves that the closed-loop system composed of the output observation error, the velocity observation error and the trajectory tracking error is exponentially mean square uniformly stable. By adjusting the parameters, these errors and their derivatives tend to be in any small neighborhood near zero. The simulation results show the effectiveness of the output observer, the speed observer and the output feedback controller.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP242

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