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This paper focuses on a class of continuum robot manipulators that uses cables for actuation. In order to realize more natural and various motions like human musculoskeletal, tendon-driven manipulators is studied. It is challenging to design the manipulator structure which consists of bones and redundant muscles. A comprehensive study is presented including the theoretical analysis of the mechanical design, kinematics, dynamics and tracking control of a planar continuum backbone robot. Lagrange's equation is applied to the dynamic problem and the system is controlled by a computed torque/time delay approach. This paper explores the fundamental limitations of dynamic problem for different loading conditions and the behavior is formulated based on the motion constraints. For example, the cable forces are computed considering the yield stress. Moreover the effects of cable configuration are examined by comparing the model performance. Meanwhile, the geometrical parameters have an important effect on manipulation. The analysis is applied on two main robot structures considering geometrically constrained deformable continuum body. The simulation results illustrate the efficiency of the proposed design and controller. Nevertheless, the field of continuum and hyper-redundant manipulation holds great promise also in the experimental domains.

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Accuracy and numerical calculation time are the two main challenges of continuum robots dynamics modeling. In fact, the numerical calculation times of exact models are so long, that they are not practical in applications such as real-time control. This paper presents a new method for dynamics modeling of continuum robot backbones. In this method, the backbone shape is considered as an arbitrary number of constant-curvature (circular arc) elements, and the dynamics model is derived using Lagrange energy methods. First, kinetics and kinematics of one element are derived. Then, the robot kinematics is derived, as a series of such elements. Finally, the robot dynamics model is derived, using Euler-Lagrange method. This paper is focused on dynamics of the flexible body of continuum robots, and the proposed model is independent of actuation systems. Besides, the numerical singularity of the constant-curvature elements is avoided, which occurs when an element is straight. The model is validated using experimental results. Comparison of simulation and experimental results shows the accuracy of the proposed method on dynamics modeling. Furthermore, the calculation time of the model is short enough to make it practical for applications such as real-time control.

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In this study, it has been tried to provide a new model for the structure of a backbone arm, to repel the shortcoming in the generation and transmission of the motion for the continuum robots. Backbone arms such as natural structures include continuum backbones with superior properties such as the ability to adapt to the environment. The actuation power is distributed over the robot’s length and makes the shape continuously deformable. In this paper, it has been suggested to add a linkage between the backbones and the branched tendons for power transfer between the drive and backbones. The ratio of the drive torque to backbone torque is introduced as the transfer ratio. The new design is capable to create a variety of transfer ration during a cycle of motion. The state space equations are extracted by Lagrange equations. Dealing the interference of bone-bone and bone-links as geometric constraints are applied to the design and it determines the allowable range of the continuum robot's geometric parameters. This design is examined with planar simulations. To show the effectiveness of the proposed design, several simulation results are illustrated. Optimum geometrical parameters for the constant torque ratio are calculated.In contrast to previous cases with the widely used; the goal is achieved with this novel backbone continuum robot.

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In this paper, dynamics and control of a Tendon-based continuum robot is investigated. The curvature is assumed that constant in each section of continuum robot. Kinematic equation is established on the basis of the Euler-Bernoulli beam. The dynamic model of the continuum robot is derived by using Lagrange method. In this paper, robot control is performed in two parts: firstly, Dynamic model is assumed to be known and position and velocity tracking control has been by using the feedback linearization method, But uncertainties in the dynamic model, are constantly challenged the control of continuum robots. For unknown parametric quantities such as mass coefficients, one way is simply substitutes a fixed estimate for the unknown parametric quantities. In this case tracking error is not equal to zero but it’s bounded. For many applications, we cannot assume that tracking error vector is not equal to zero. In such cases we use adaptive controller. In this paper the total mass of the primary backbone and secondary backbone are uncertain parameters, therefore, a new adaptive controller is presented to estimate those uncertainties while cause to asymptotically stable for tracking error. Simulation results show good performance in velocity and position tracking.

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Origami, as a paper folding art and Japanese culture, has been utilized broadly in engineering areas. The exclusive features of origami such as negative Poisson’s ration, lightweight, deployable and so forth, can be considered in the design of deployable space structures, expandable shelters, drug delivery, and robots. In this study, firstly, the continuum robot with six serial modules of origami parallel structure as its skeleton and the helical springs as the compliant backbone is studied, and constant curvature kinematics was implemented in order to simplify and approximate the kinematic model. Accordingly, the kinematic model of one module was derived. Then, the robot kinematics was obtained as a series of mentioned modules. Furthermore, the proposed continuum robot was modeled by an equivalent mechanism, and a comparison was conducted between the methods to obtain a workspace. Based on the results, the modeling of the equivalent mechanism has an advantage in terms of calculation's volume compared to the constant curvature method and the workspace obtained from both methods was the same. The Jacobian matrix was obtained through the constant curvature approximation methods, which can be considered for singularity analysis in specific conditions and the analysis reveals that the singularities occur when the curve and radius are equal and symmetry is created and the other is when the radius is equivalent to zero. The paper concludes a perspective on several of the themes of current research that are shaping the future of origami-inspired robotics.