基于分布柔度式平面柔顺机构的微定位平台研究

发布时间：2018-11-10 09:03

【摘要】：精密定位技术是提升国家核心竞争力和综合国力的战略选择,而微定位平台的控制系统设计是精密定位技术的关键部分。分布柔度式平面柔顺机构作为一种新型的微定位机构,其不仅具有柔性机构无摩擦磨损、无运动间隙和免装配润滑的优点,还具有并联机构多运动维度、稳定高和承载能力强的特性。基于分布柔度式平面柔顺机构的微定位平台运动精度高、行程大、动态响应快、体积小,并且可以达到亚微米级的定位精度和纳米级的分辨率。因而,分布柔度式平面柔顺机构可广泛应用于精密工程、微纳制造、微电子技术等尖端领域,其运动特性分析和控制系统设计已成为国内外学者关注的焦点。本文以分布柔度式平面柔顺机构为研究对象,主要探讨了机构的运动学特性和动力学特性,分析了机构控制器的设计及其控制系统的建立,最后通过实验测试验证了机构建模和理论分析的正确性。具体的研究内容如下:(1)基于分布柔度式平面柔顺机构的矢量同构模型,采用微位移法对机构进行运动学分析,得到了机构的输入输出Jacobian矩阵。通过仿真得到了机构的位移/转动云图和应力云图,验证了机构的运动特性和Jacobian矩阵的有效性。(2)运用拉格朗日方程(Lagrange法),建立了分布柔度式平面柔顺机构的刚体动力学模型;基于梁单元模型和运动弹性动力学原理(KED法),建立了分布柔度式平面柔顺机构的弹性动力学模型。在此基础上,对机构进行模态分析,得到了机构的三阶固有频率和振型图,验证了机构动力学模型的有效性。(3)基于分布柔度式平面柔顺机构的弹性动力学方程和滤波器,设计了一种滑模变结构控制器(SMC),并构造了李雅普诺夫(Lyapunov)函数来证明该控制器的稳定性。结合S-Function函数和Simulink框图,建立了机构的控制系统。通过仿真,得到了机构的位移轨迹跟踪曲线及其误差曲线。(4)对分布柔度式平面柔顺机构进行实验测试,得到了机构输出耦合、定位精度和运动轨迹三个方面的实验数据,并将其与理论计算值进行比较,分析了数据误差产生的原因,验证了机构理论分析的正确性。
[Abstract]:Precision positioning technology is a strategic choice to enhance national core competitiveness and comprehensive national strength, and the control system design of micro-positioning platform is the key part of precision positioning technology. As a new type of micro-positioning mechanism, the distributed flexibility planar compliant mechanism not only has the advantages of no friction and wear, no movement clearance and no assembly lubrication, but also has multiple kinematic dimensions of parallel mechanism. High stability and high bearing capacity. The micro-positioning platform based on distributed flexibility planar compliant mechanism has high motion accuracy, large stroke, fast dynamic response, small volume, and can achieve sub-micron positioning accuracy and nanoscale resolution. Therefore, the distributed flexibility planar compliant mechanism can be widely used in the fields of precision engineering, micro / nano manufacturing, microelectronics technology and so on. The analysis of its motion characteristics and the design of its control system have become the focus of attention of scholars at home and abroad. In this paper, the kinematic and dynamic characteristics of the distributed compliance planar compliant mechanism are discussed, and the design of the controller and the establishment of the control system are analyzed. Finally, the correctness of mechanism modeling and theoretical analysis is verified by experimental test. The specific research contents are as follows: (1) based on the vector isomorphism model of the distributed compliance planar compliant mechanism, the kinematics analysis of the mechanism is carried out by using the micro-displacement method, and the input and output Jacobian matrix of the mechanism is obtained. The displacement / rotation cloud diagram and stress cloud diagram of the mechanism are obtained by simulation. The kinematic characteristics of the mechanism and the validity of the Jacobian matrix are verified. (2) the Lagrangian equation (Lagrange method) is used. The rigid-body dynamics model of the planar compliant mechanism with distributed flexibility is established. Based on the beam element model and the principle of kinematic elastodynamics (KED method), the elastic dynamic model of the distributed flexibility planar compliant mechanism is established. On this basis, the modal analysis of the mechanism is carried out, and the third order natural frequency and mode diagram of the mechanism are obtained, which verifies the validity of the dynamic model of the mechanism. (3) based on the elastic dynamics equation and filter of the distributed compliance type planar compliant mechanism, A sliding mode variable structure controller (SMC),) is designed and the Lyapunov (Lyapunov) function is constructed to prove the stability of the controller. Combined with S-Function function and Simulink block diagram, the control system of the mechanism is established. Through simulation, the displacement trajectory tracking curve and its error curve of the mechanism are obtained. (4) the experimental data of the distributed flexibility planar compliant mechanism are obtained in three aspects: output coupling, positioning accuracy and motion track. Compared with the theoretical calculation, the reason of the data error is analyzed, and the correctness of the mechanism theory analysis is verified.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH112

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