Dynamics and Control of Non-Laminated Actuators for Magnetic Levitation

该补助金为制造业高性能磁悬浮的研究提供资金。 要求极高清洁度、极高精度定位或非接触式零件处理的制造工艺的增长表明磁悬浮在生产环境中的作用越来越大。 磁悬浮作为一种技术，在电力电子、精密位置传感、高速数字信号处理和控制理论的巨大进步的推动下，正在迅速发展。 磁悬浮已在许多工艺中得到应用，包括金属输送、金属涂覆、硅晶片输送、薄膜拉伸和光刻。 几乎所有的高性能磁悬浮研究都假设致动器可以由叠片构成，以便在主动控制引起的快速变化的磁场中最大限度地减少涡流的产生。 然而，在许多当前或预期的应用中，层压结构与基本工艺相冲突，或者成本很高。 在没有叠片的情况下，施加到电磁体的线圈的电流的快速变化由于由变化的场在致动器内感生的涡电流而导致施加的力的慢得多的变化。 这些电流与所产生的场相互作用，并使致动器的动态特性大大复杂化。 如果已知的话，致动器动态可以通过精心设计的控制算法来部分补偿，以便实现改进的刚度和伺服带宽。 然而，它们也对悬浮性能施加了基本限制。因此，预测、识别和建模非叠层致动器动态特性的能力对于获得高刚度/带宽悬浮和理解不能实现的是至关重要的。 本研究工作的理论和实验任务的目标是：（1）确定涡流效应对主动磁悬浮性能的基本限制，以及（2）开发鲁棒控制策略，该策略使用非叠层致动器提供非常高的性能水平。如果成功，这项研究工作将使非层压磁悬浮能够提供高度精确的定位，而不管干扰力，并快速地重新定位悬浮物体。 这项工作还将提供一个基本的知识基础，将连接致动器的动态特性，其大小，几何形状和组成。 这些知识将允许预测磁悬浮性能极限以及优化定子设计，以最大限度地提高刚度和伺服带宽。 最后，预计这项研究将有助于确定高性能磁悬浮制造的新机会。

This grant provides funding for an investigation of high performance magnetic levitation for manufacturing. The growth of manufacturing processes that require extreme cleanliness, very high precision positioning or non-contact part handling suggests an increasing role for magnetic levitation in production environments. As a technology, magnetic levitation is developing rapidly, spurred by dramatic advances in power electronics, precision position sensing, high speed digital signal processing, and control theory. Magnetic levitation has found application in many processes including metal conveyance, metal coating, silicon wafer transport, film stretching, and photolithography. Almost all work in high performance magnetic levitation assumes that the actuator can be constructed from laminations so as to minimize the production of eddy currents in the face of the rapidly varying magnetic fields caused by active control. However, in many current or anticipated applications, laminated construction conflicts with the basic process or would be highly costly. Without laminations, a rapid change in current applied to the electromagnet's coil results in a much slower change in the applied force due to the eddy currents induced within the actuator by the changing field. These currents interact with the produced field and greatly complicate the actuator's dynamics. If known, the actuator dynamics can be partially compensated by a well-designed control algorithm so as to achieve improved stiffness and servo bandwidth. However, they also impose fundamental limits upon levitation performance. Thus, the ability to predict, identify, and model non-laminated actuator dynamics is critical to attaining high stiffness/ bandwidth levitation and to understanding what can not be achieved. The objectives of the theoretical and experimental tasks of this research effort are to (1) determine the fundamental limits that eddy current effects impose upon the performance of active magnetic suspensions, and (2) develop robust control strategies that provide very high levels of performance with non-laminated actuators.If successful, this research effort will enable non-laminated magnetic suspensions that provide highly accurate positioning in spite of disturbance forces and reposition the levitated object quickly. The effort will also provide a fundamental knowledge base that will connect an actuator's dynamic properties to its size, geometry, and composition. This knowledge will allow the prediction of magnetic suspension performance limits as well as the optimization of the stator design to maximize stiffness and servo bandwidth. Finally, it is anticipated that this research will help define new opportunities in manufacturing for high performance magnetic suspension.