Design and research of robot joint actuated by SMA wire

In an effort to improve the convenience and modularization in the current methods proposed to design the actuated joint for robots, an approach is suggested and detailed by the design of an artificial muscle based actuated joint. The design methods is an integrated actuated joint mechanism for robots by using the gemel and SMA(Shape Memory Alloy, SMA) wires as the structure and muscle actuators respectively. In addition, a Cartesian coordinate system of the joint mechanism is formed to optimize the geometrical dimensions, and a mathematically model is constructed to reflect the relationships between the geometrical parameters, intensity, output torque and angular displacement of actuated joint. Furthermore, the model is solved by the multi-objective programming algorithm based on MATLABTM Optimization Toolbox function. The proposed method is demonstrated by its application in a sciatic joint design from a quadruped robot project, and the benefits of SMA muscle based actuated joint are highlighted in terms of strength, dexterity, and bearing.