Locomotion modeling of an actinomorphic soft robot actuated by SMA springs

The article introduces an actinomorphic soft robot that possesses a flattened body with a number of arms radially symmetric distributing and extending from robot central disc. Hence, mimicking radially symmetric musculature animals like starfish. The robot arm system, consisted of arm and smart material alloy (SMA) springs is the support structure as well as the robot propulsion device. A novel approach which regards robot movement as a spatial close-chain mechanism was applied to analyze the robot locomotion modal. The locomotion model of actinomorphic robot was built in virtual platform by synthesizing forward robot kinematics using modified Denavit-Hartenberg (D-H) method, robot locomotion modal and robot motion equations under quasi-static approximation. At last, the experiment and simulation of a three arm actinomorphic robot were conducted, and they presented similar locomotion characteristics of movement rhythm and direction which prove the robot locomotion model available.