Little Strong and Little Stronger: Design and Control of the Twin Hexapods

In this paper we present new designs of the twin hexapods, Little Strong and Little Stronger, as shown in Fig. 1. The twins share similar designs with slightly different focuses, but both have flexible and dynamic locomotion performance. We also improved the corresponding control algorithms in two ways. We first take Centroid Balance Control (CBC) algorithm in joint space to distribute Ground Reaction Forces (GRFs) more reasonable and in accordance with biological intuition. Then we hire Nonlinear Model Predictive Control (NMPC) to overcome the difficulty of insufficient online real-time computing, complying with the higher computation and more complex control requirements of hexapods. We compared the modified progressive optimization control algorithms and conducted some interesting experiments on the twin robots, to meet the requirements of the 2022 Beijing Winter Olympics torch relay.