Mesoscale piezoelectrically driven mechanisms - design, modeling, fabrication, and control

机械和机器人仍然难以在小尺度上制造和驱动。虽然这些挑战已经在中型到大型机器人中找到了合适的解决方案，但在中尺度上，在一毫米到厘米的量级上，这些挑战仍然存在。压电材料是一种可能解决驱动挑战的材料，因为当电场施加在它们身上时，它们会产生应变。特别是在小尺度上，通过压电效应的驱动是有利的。虽然只产生小位移，但这些执行器具有大带宽，因此可以产生快速和精确的运动。这项研究计划有三个主要目标，即利用新的制造技术来制造新的压电电机和压电驱动的并联机器人。第一个目标是为压电驱动结构找到具有成本效益的制造技术。第二种是根据我最近的工作，基于一系列的单形臂来制造平面压电马达。我设计并制作了一系列平面直径为9mm，厚度小于0.8 mm的压电电机样机。因此，我们的目标是继续研究这种压电电机的设计、建模和制造，以提高其在小型机器人中的性能。第三个目标是利用这些制造技术来创建平行机器人机构，这是我之前在基于压电堆栈致动器的三自由度纳米定位平台上的研究成果。这项工作将涉及变速箱和多个自由度关节的设计，并在一个平面并联五杆机器人上进行演示，最终实现创建微型斯图尔特平台的长期目标。该平台将实现高运动频率的大工作空间。这项研究计划的总体目标是在中尺度上设计低成本的压电驱动电机和机制。通过采用开发的设计、建模、制造和控制技术，将追求许多应用，如手术器械、微型装配、微型到飞米级卫星的操纵器和微型自动驾驶汽车，同时为HQP培训提供独特和新颖的机会。

Mechanisms and robots remain difficult to fabricate and actuate at small scales. While these challenges have found suitable solutions in medium to large scale robotics, at the mesoscale, on the order of a millimeter to centimeters, these challenges remain. Piezoelectric materials represent one possible solution to the challenge of actuation as they are materials that strain when an electric field is applied across them. At small scales in particular, actuation via the piezoelectric effect becomes favourable. While generating only small displacements, these actuators have a large bandwidth and hence can generate fast and precise movements. This research program has three main objectives which are to leverage new fabrication techniques in order to create new piezoelectric motors and parallel robots that are piezoelectrically driven. The first objective is to find cost effective fabrication techniques for piezoelectrically driven structures. The second is to build from my recent work to create planar piezoelectric motors based on a series of unimorph arms. I have designed and fabricated a series of prototypes of a piezoelectric motor which has a planar diameter of 9 mm and a thickness of less than 0.8 mm. Hence, the goal is to continue work on the design, modeling, and fabrication of this piezoelectric motor to increase its performance for small scale robotics. The third objective is to leverage these fabrication techniques to create parallel robotic mechanisms which leads from my previous work on a three degree of freedom nanopositioning platform based on piezoelectric stack actuators. This work will deal with the design of transmissions and multiple degree of freedom joints with demonstration on a planar parallel five-bar robot, en route to the final long term goal of creating a miniature Stewart platform. This platform will achieve a large workspace with high motion frequencies. The overarching goal of this research program is to engineer low-cost piezoelectrically driven motors and mechanisms at the mesoscale. By employing the developed design, modeling, fabrication, and control techniques, a number of applications will be pursued such as surgical instruments, micro-assembly, manipulators for pico to femto class satellites, and miniature autonomous vehicles while offering a unique and novel opportunity for HQP training.