Parallel robots are capable of high-speed manipulation and have become essential tools in the industry. The proximal placement of their motors and the low weight of their end effectors make them ideal for generating highly dynamic motion. Therefore, parallel robots can be adopted for motion platform designs, as long as end effector loads are low. Traditional motion platforms can be large and powerful to generate multiple g acceleration. However, these designs tend to be expensive and large. Similar but smaller motion platforms feature a small work range with reduced degrees of freedom (DoFs) and a limited payload. Here we seek a medium-sized affordable parallel robot capable of powerful and high-speed 6-DoF motion in a comparably large workspace. This work explores the concept of a quadruped robot flipped upside-down, with the motion platform fixed between its feet. In particular, we exploit the high-power dynamic brushless actuation and the four-leg redundancy when moving the motion platform. We characterize the resulting motion platform by tracking sinusoidal and circular trajectories with varying loads. Dynamic motions in 6 DoFs up to 10 Hz and ~10 mm amplitude are possible when moving a mass of 300 grams. We demonstrate single-axis end-effector translations up to ~20 mm at 10 Hz for higher loads of 1.2 kg. The motion platform can be replicated easily by 3D printing and off-the-shelf components. All motion platform-related hardware and the custom-written software required to replicate are open-source.

翻译：并联机器人具备高速操控能力，已成为工业领域的重要工具。其电机近端布置与末端执行器轻量化特性，使其特别适合产生高动态运动。因此，只要末端执行器载荷较低，并联机器人便可应用于运动平台设计。传统运动平台通常体型庞大且驱动力强劲，可产生数倍重力加速度，但这种设计往往成本高昂且体积巨大。类似的小型运动平台虽能实现有限工作空间内的降自由度（DoFs）运动，但有效载荷能力受限。本文旨在探索一种中等尺寸、经济可行的并联机器人，可在相对较大的工作空间内实现高速高功率六自由度运动。本研究提出将四足机器人倒置的概念，使运动平台固定在其足端之间。具体而言，我们利用高功率动态无刷驱动系统及四腿冗余特性来驱动运动平台。通过追踪不同载荷下的正弦轨迹和圆形轨迹，对所得运动平台进行性能表征。结果表明，在承载300克质量时，可实现在六个自由度上最高10 Hz频率、约10毫米振幅的动态运动；当载荷增至1.2千克时，单轴末端执行器可在10 Hz频率下实现约20毫米平移。该运动平台可通过3D打印技术及现成组件轻松复现，所有相关硬件及自主编写的复现软件均以开源形式发布。