【作者】 王斌；

【导师】 邱志成；

【作者基本信息】 华南理工大学 ， 机械电子工程， 2012， 硕士

【摘要】 柔性机械臂具有质量轻、负载大、速度快、能耗低、发射成本低等优点，在工业场合和空间机器人中应用越来越广泛。由于柔性机械臂在运动过程中会产生扭曲、剪切等弹性变形，引起机器人末端的弹性变形误差，从而影响机器人的运动精度。柔性机械臂的模态阻尼很小，在运动时或定位时容易产生弹性振动，影响运动平稳性和定位精度，高频小幅值振动可以较快速的衰减，但是其低频大幅值振动会持续很长的时间，这不仅影响了系统的控制精度和稳定性，还会引起结构的疲劳破坏，因此需要对其采用主动控制，抑制振动。针对柔性机械臂的振动问题，提出了一种基于无杆气缸驱动和压电片驱动器同时作用的振动控制方案。采用脉冲码调制方法(Pulse Code Modulation，PCM)构建气动回路控制气缸活塞的运动，同时进行气缸基座定位和柔性臂振动控制，同时利用压电片驱动器对柔性臂振动进行抑制。活塞的位移由直线光栅尺传感器测量，柔性臂的振动由表面粘贴的压电陶瓷片作为传感器进行测量。完成了系统的数学建模、算法仿真和试验研究。首先，提出了无杆气缸驱动和压电片驱动器同时作用的振动控制方案，包括基于气动PCM控制方式的气动回路和信号采集电路以及控制系统。分别采用Hamilton原理和Lagrange原理对系统进行了动力学建模，并给出其标准状态空间方程及离散化形式，为系统特性分析、控制算法仿真以及控制器设计提供基础。其次，进行模糊自适应控制算法数学仿真研究。设计了PD控制算法、模糊控制算法、变论域模糊控制算法和直接自适应模糊控制算法，并进行了闭环稳定性分析。并分别进行了气动定位和振动控制仿真研究，为控制实验提供参考。最后，为了验证气动驱动振动控制方案和控制算法的可行性，建立了基于无杆气缸驱动和压电驱动器复合控制柔性机械臂振动实验平台。完成了系统的机械结构设计、电气控制部分硬件电路设计和系统软件设计。主要包括：光栅尺信号四倍频、辨向、脉冲计数电路、A/D转换数据采集电路、D/A转换和信号调理电路及其驱动程序和实时控制系统。并进行了基于无杆气缸驱动和压电驱动器复合控制的实验比较研究。理论分析、仿真和试验研究结果表明，提出的气动驱动控制方案及采用的算法可快速抑制柔性臂的振动，同时实现气缸基座的定位，证明了所提出的气动驱动控制方案的可行性和所采用的控制策略的有效性。更多还原

【Abstract】 The characteristics of flexible manipulators are light weight, high speed; low energyconsumption and low launch costs, widely used in industrial applications and space robots.Because the flexible manipulator in the process of movement will produce distorted, shear theelastic deformation, causing the robot end elastic deformation error, thus affecting theaccuracy of the robot’s movement. Flexible manipulator has low modal damping, inmovement or positioning was prone to produce elastic vibration, which affects the smoothmotion and positioning accuracy. High frequency small amplitude vibration can be more rapiddecay, but its low frequency large amplitude vibration will last a very long time. Consequently,it will not only affect the control accuracy and stability of the system, but also cause structuralfatigue of flexible manipulators. In order to meet the requirements of high stability and highpositioning accuracy, active control must be applied for suppressing structural vibrations offlexible manipulators.A rodless cylinder based pneumatic driving scheme was proposed to suppress thevibrations of flexible beam. Pulse code modulation (PCM) method was employed to controlthe motion of piston rod for simultaneous positioning and vibration control. The positionsignal of the piston is measured by the linear grating sensors, while the vibration of the beamwas measured by a piece of piezoelectric ceramic patch (lead Zirconate Titanate, PZT)bonded on the beam’s surface. Mathematic modeling, simulation and experimental researchusing control algorithms have been carried out.Firstly, the pneumatic drive based flexible beam system was proposed. It comprised thepneumatic circuit constructed by means of PCM method, signal acquisition circuit andcontroller system. Then, the dynamic model of the system was obtained by using Hamiltonprinciple and Lagrange principle, and its standard state space form was provided forcharacteristic analysis, control algorithms simulation and controller design.Secondly, the adaptive fuzzy control algorithms for mathematical simulation wereconducted. PD controller, fuzzy controller, the variable universe fuzzy controller and directadaptive fuzzy controller were designed, and the closed-loop stability analysis wrer carriedout. Conducted a simulation study of the pneumatic positioning and vibration control, providea reference for the control experiments.Finally, in order to verify the feasibility of the proposed pneumatic driving scheme andthe adopted intelligent control algorithms, an experimental setup of a flexible beam driven bya pneumatic rodless cylinder was constructed. The mechanical structure of the system, hardware circuit and system software of the electrical control were designed, which includethe Quadruplicated Frequency of the grating signal, and distinguish the pulse counting circuit,data acquisition A/D conversion circuit, the D/A conversion and signal conditioning circuitand its driver softwares and real-time control system. The experimental research forsuppressing vibrations of the flexible beam and positioning based on the rodless cylinder andthe piezoelectric actuators was conducted.The theoretical analysis, numerical simulation and experimental results demonstratedthat the proposed pneumatic drive control program and the algorithms can suppress thevibration of the flexible beam and achieve the positioning of the cylinder base simultaneously.更多还原