基于平面电机驱动的多自由度定位平台控制方法研究

发布时间：2018-12-26 18:49

【摘要】：目前,诸如集成电路制造、微机电系统加工制造等产业都对多自由度精密定位平台有着十分迫切的需求。研制一种具有多自由度、定位精度较高、结构简单以及推力较大等特点的精密定位平台已经迫在眉睫。本文将针对由改进Y形平面电机驱动的多自由度精密定位平台的控制方法、出力特性的优化、热特性等问题进行分析。首先,本文针对改进Y形平面电机的耦合机理进行了分析,发现系统的控制模型有较强的耦合特性,进而根据其耦合特性设计了解耦算法。算法主要应用了线性化思想。通过假设一组与各自由度力矢量成比例的控制电流来对各自由度的运动进行控制,使得各自由度运动的控制模型得以独立。除此之外,本文还对影响改进Y形平面电机出力特性的主要原因进行了分析。针对动子翻转运动和线圈绕组内反电动势引起的推力波动加以了补偿,减小了平面电机推力的波动,提高了控制精度。其次,本文根据改进Y形平面电机的结构特点设计了一种独立水套式的冷却结构。通过仿真计算的方式确定了冷却结构的蛇形水厚度为4mm。此时对流散热系数达到5.6×103W/(m2·℃),进而利用该参数对驱动单元的温度场进行了仿真。在未添加强制水冷的条件下,当驱动单元两线圈绕组内电流均为2A时,驱动单元最高温度达到了77℃。加入强制水冷后,同等条件下驱动单元的最高温度下降到30℃。加入强制水冷后驱动单元推力变化由-2.16%下降到-0.3%以下。除此之外,通过对驱动单元进行的温升实验,验证了仿真结果。最后,本文搭建了实验平台并对所设计定位平台的运动指标进行了实验测试。实验表明定位平台Y方向的行程为7mm,位移分辨力达到7μm,空载最大加速度不小于0.34m/s2,负载为1kg时最大加速度不小于0.27m/s2,推力不小于1.31N。定位平台X方向的行程为6.8mm,位移分辨力达到7μm,空载最大加速度不小于0.42m/s2,负载为1kg时最大加速度不小于0.33m/s2,推力不小于1.54N。定位平台Rz方向的行程为±0.6°,转动分辨力达到11.5″。本文还针对定位平台各自由度运动的耦合情况进行了实验测试,并且针对定位平台在二维平面上任一点的定位以及跟随特性进行了圆形轨迹运动实验。
[Abstract]:At present, many industries, such as integrated circuit manufacturing, micro-electromechanical system manufacturing and so on, have an urgent need for multi-degree-of-freedom precision positioning platform. It is urgent to develop a precision positioning platform with many degrees of freedom, high positioning accuracy, simple structure and large thrust. In this paper, the control method of multi-degree-of-freedom precision positioning platform driven by the improved Y-shaped planar motor, the optimization of the output characteristics and the thermal characteristics are analyzed. Firstly, this paper analyzes the coupling mechanism of the improved Y-shaped planar motor, finds that the control model of the system has strong coupling characteristics, and then designs a decoupling algorithm according to its coupling characteristics. The linearization idea is mainly used in the algorithm. By assuming a set of control currents proportional to the force vectors of each degree of freedom to control the motion of each degree of freedom, the control model of the motion of each degree of freedom is independent. In addition, the main reasons that affect the improvement of the output characteristics of Y-shaped planar motor are also analyzed in this paper. The thrust fluctuation caused by the rotor flipping motion and the back EMF in the coil winding is compensated to reduce the thrust fluctuation of the planar motor and to improve the control precision. Secondly, an independent water-sleeve cooling structure is designed according to the structural characteristics of the improved Y-shaped planar motor. The thickness of the snake-shaped water of the cooling structure is determined to be 4 mm by simulation. The convection heat dissipation coefficient is 5. 6 脳 103W/ (m2 鈩，

本文编号：2392539