Biomimetic upper limb mechanism of humanoid robot for shock resistance based on viscoelasticity

Humanoid robots encounter high falling risks when they walk or operate in an uncertain environment. In this paper, we propose a biomimetic mechanism for the upper limb of a humanoid robot that provides shock resistance when the robot falls forward. This biomimetic mechanism is based on viscoelasticity, and was modeled on human bones and muscles to achieve supporting and buffering. We install a series elastic component within the robot's elbow and also install a viscoelastically active pneumatically actuated impact protection device. We perform the falling forward experiments using our experimental platform, and we employ encoder, IMU, air gauge and F-T sensor to collect the experimental data. Based on the analysis of the experimental data, we conclude that the proposed biomimetic mechanism which is modeled on actual human bones and muscles can support the robot body, absorb the falling impact and against falling damage.