Continuum robots, in contrast with traditional rigid-link robots, have a continuous backbone with no joints; Traditional robots have rigid underlying structures that limit their ability to interact with their environment. These robots often encounter difficulties operating in unstructured and highly congested environments. Many animals and plants exhibit complex movement with soft structures. Muscular hydrostats (e.g. octopus arms and elephant trunks) are almost entirely composed of muscle and connective tissue. Also, plant cells can change shape when pressurized by osmosis. Researchers have been iired by biology to design and build soft robots. With a soft structure and redundant degrees of freedom, these robots can be used for delicate tasks in cluttered and/or unstructured environments.Over the last decade; researchers have developed continuum robots that provide new capabilities relative to traditional robots. The most commonly used continuum robots are kinematically no redundant. These robots are typically used in well-de?ned environments in which they repetitively perform prescribed motion with great precision. This capability is used in many successful applications, primarily in manufacturing. These robots are designed to be stiff so that vibration and deformation of the structure and drivetrain do not reduce the accuracy of movement. In general, hard robots have multiple ?exible joints connected by stiff links. In this research, a new dynamic model for continuum robot manipulators is derived. A geometric model of a 3-link continuum robot manipulator with a circular cross-section is considered. This model is assumed to have no torsional effects. We introduce a method for deriving kinematic relationships for a general and potential energy of the manipulator is obtained by sum of the kinetic and potential energy of all trunks elements and the elastic potential energy of the bending SMA wires. Using the Lagrange equation, the dynamic model of a continuum robot manipulator is obtained. Three different control approaches including computed torque method, sliding mode and adaptive sliding mode are stated for the proposed model. Each of the controllers' performances is evaluated in different conditions. Numerical simulation results are presented for a spatial 3-section continuum robot manipulator. The numerical results indicate that the control system has a high degree of accuracy and robustness specifically with the adaptive-sliding control scheme. Keywords: Continuum Robot, Dynamic Modeling, Computed Torque Control, Sliding Mode Control, Adaptive- Sliding Mode, SMA Wire.
