基于自抗扰的板球系统控制研究

发布时间：2018-03-28 14:31

本文选题：板球系统　切入点：非线性　出处：《北京理工大学》2016年硕士论文

【摘要】：板球系统由二维的板和在板上滚动的小球组成,小球在重力的作用下在板上滚动。本文针对搭建的三自由度并联机构板球系统进行分析,开展了基于自抗扰的板球系统的控制研究,并通过仿真和实物验证了控制算法的有效性。首先对小球在板上的运动过程进行了分析,明确了小球在板上滚动的条件,并建立了小球在板上滚动的数学模型。本论文所研究板球系统的执行机构是由三台直线电机构成的三自由度并联机构。本文针对三自由度并联机构的耦合,运用几何关系解耦,确定了动平台上板的姿态与直线电机伸长量之间的关系,由此设计了通过控制直线电机控制板的姿态,进而控制小球的运动的方案。之后对电机及驱动器模型进行分析和辨识,并进一步建立了板球系统的整体模型。然后对板球系统中存在的不确定性扰动、板与球间的摩擦力以及向心力项和耦合项进行了分析,并设计了扩张状态观测器将其作为总扰动的一部分进行估计和补偿,用自抗扰控制器实现小球的轨迹跟踪,并进行了仿真。之后针对采集小球的位置坐标存在的量测噪声,设计一阶低通滤波器,并针对原系统和一阶低通滤波器构成的复合系统设计了含一阶惯性环节的扩张状态观测器;并对含一阶惯性环节的扩张状态观测器进行了频域分析。为了使板的角度在较小的范围内变化,将控制量引入性能指标,设计了线性二次型最优控制器;结合自抗扰控制器可知,带加速度前馈的自抗扰控制器也是线性二次型最优控制器的一种形式。并对板球系统的定点控制和轨迹跟踪控制进行了仿真。最后完成实验平台的搭建、调试和控制软件的编写,并进行定点实验和轨迹跟踪实验,验证了控制算法。针对实验中观测器出现的Peaking现象,进行了理论分析,提出了将扩张状态观测器初始化使其初始状态与实际状态尽量一致的方案,克服了严重的Peaking现象,使控制精度达到了较高的水平。
[Abstract]:The cricket system consists of two dimensional plates and the ball rolling on the board. The ball rolls on the plate under the action of gravity. The control research of cricket system based on ADRC is carried out, and the effectiveness of the control algorithm is verified by simulation and real object. Firstly, the motion process of the ball on the board is analyzed, and the rolling condition of the ball on the board is determined. A mathematical model of the ball rolling on the plate is established. The actuator of the cricket system studied in this paper is a 3-DOF parallel mechanism composed of three linear motors. In this paper, the coupling of the three-degree-of-freedom parallel mechanism is decoupled by geometric relations. The relationship between the attitude of the plate on the moving platform and the elongation of the linear motor is determined. The scheme of controlling the motion of the ball by controlling the attitude of the control board of the linear motor is designed. Then the motor and driver models are analyzed and identified. Furthermore, the integral model of cricket system is established, and the uncertainty disturbance, friction between plate and ball, and the terms of centripetal force and coupling are analyzed. The extended state observer is designed to estimate and compensate it as part of the total disturbance, and the trajectory tracking of the ball is realized by the ADRC, and the simulation is carried out. Then, the measurement noise of the position coordinates of the acquired sphere is measured. The first order low pass filter is designed and the extended state observer with first order inertial link is designed for the composite system composed of the original system and the first order low pass filter. The extended state observer with first order inertial link is analyzed in frequency domain. In order to change the angle of the plate in a small range, the control quantity is introduced into the performance index, and the linear quadratic optimal controller is designed. Combined with active disturbance rejection controller, Auto-disturbance rejection controller with acceleration feedforward is also a form of linear quadratic optimal controller. The fixed-point control and trajectory tracking control of cricket system are simulated. The debugging and control software is written, and the fixed-point experiment and trajectory tracking experiment are carried out to verify the control algorithm. The Peaking phenomenon of the observer in the experiment is analyzed theoretically. A scheme is proposed to initialize the extended state observer so that its initial state is as consistent as possible with the actual state. The scheme overcomes the serious Peaking phenomenon and makes the control precision reach a higher level.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP273

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