Design of a basic module for angular motion of spherical joints using the actuators of shape memory alloys and magnetic stabilization system

Spherical joints are specifically used in many robotic systems, including various industrial and medical applications, especially in non-structured environments. Modular robotic systems are the appropriate solution for use in these environments; So that the configuration of the robots can change quick and easy by link or separate different modules. Flexibility of modules, enough degrees of freedom, capability to stabilize the position of the module and rigidity to maintain strength and stiffness of modular robot during mission are the most important features of a modular robot. Shape memory alloys are suitable actuators for use in robotic modules, which a tiny, lightweight, and without noise system is achieved by using them. In this paper, a mechanism with two degrees of freedom has been created by placing three memory shape alloys springs in the structure of a flexible joint module. Also, with the installation of an electromagnetic system in the joint, it is possible to stabilize its position when necessary. The developed module, in addition to its high flexibility, can maintain its position when needed and increase the strength of the robotic arm. In this research, the design of the module has been presented and kinematic and force analysis has been investigated.