Design of a Compact Rat-inspired Waist Mechanism for a Biomimetic Robot

this paper, we designed a new bio-inspiredcompact waist mechanism for a robotic rat to allow a better imitation of rat movement. With the observation and analysis of animal movement recordings, we found that the dorsal spine of a rat played an important role in agile pitch and yaw movements. To mimic such agile movements, we designed a new waist mechanism inspired by the muscle-tendon actuation pattern of rat spine. The proposed mechanism consists of two sets of parallel placed linkages for driving pitch and yaw movement, respectively. Although actuated by only one DC motor, each set of the linkages was able to output $ 2-\mathrm {D}\mathrm {O}\Gamma $ movement. Consequently, the agile pitch and yaw movements were achieved in a compact space with this new rat-inspired mechanism. Compared with previously designed waist, the new one enables a wider range of movement. Remarkably, the volume and weight were decreased 50% and 67% respectively. Additionally, it similar to a rat's waist in terms of both dimension and actuation pattern.