Design Paradigm for Human Size Manipulator With High Payload, Repeatability, and Bandwidth

Manipulators applied in daily life, like exoskeletons or humanoid robots, always require excellent comprehensive performance comparable to or even surpassing that of humans to deal with diverse tasks. However, it is quite challenging to achieve all the performance simultaneously. This article presents a design paradigm to enable manipulation systems with favorable comprehensive performance of high payload, repeatability, and bandwidth. A novel three-RRR coaxial spherical parallel mechanism was realized to achieve high payload and bandwidth. Structure optimization was conducted to improve the torque output performance and expand the workspace. High-performance actuators, known for their high torque and bandwidth, were designed to ensure a high upper bound of overall system performance. A linkage transmission mechanism with high stiffness was employed to ensure a high repeatability. The prototype designed under the paradigm featured human size and provided favorable performance of 10 kg payload with arm fully straight, repeatability within 0.5 mm, and 11.9 Hz for position control bandwidth.