Design and analysis of a family of snake arm robots connected by compliant joints

• A novel family of snake arm robots connected by compliant joints is introduced.
• This family of robots has high flexibility and an appropriate stiffness.
• A novel actuation construction is presented for minimizing the actuation system.
• A new kinematic model for this family of robots is introduced.
• Jacobian is presented to evaluate stiffness and velocity for the family of robots.

Snake arm robots have flexible continuous constructions which can be used for accessing confined places in many fields, e.g., minimally invasive surgery and industry assembly. This paper proposes a novel design of a snake arm robot which has a unique twin actuation construction and maintains the cable tension in any arbitrary configuration. Also, this design has a great flexibility (bend capability) and an appropriate stiffness enabled by compliant joint construction. Further, a kinematic model for this construction is introduced, which is among the most efficient method along the existing approaches. This model can significantly simplify the kinematics of this cable driven system and Jacobian of snake arm robot that is also described in detailed. Furthermore, based on a proposed Jacobian, the stiffness for multi-compliant joint connected snake arm robot is presented. Finally, all the analyses have been verified by Finite element model.