Development of a Multi-Cable-Driven Continuum Robot Controlled by Parallel Platforms

2020 ◽  
pp. 1-11 ◽  
Author(s):  
Xinbo Chen ◽  
Jiantao Yao ◽  
Tong Li ◽  
Haili Li ◽  
Pan Zhou ◽  
...  

Abstract Cable-driven continuum robots exhibit excellent capabilities in the unstructured environment due to their inherent compliance and dexterity. To improve the reliability and load capacity of continuum robots, increasing the number of cables is often used in the control of continuum robots. However, the number of actuators will increase with the cables. To tackle this challenge, this work proposes a method for increasing the number of cables without increasing actuators in a continuum robot through parallel platforms. The parallel platforms are used to control all the cables in the continuum robot, and can be separated from the continuum robot to enable the remote drive of a manipulation arm by using the cable-tube structure. The manipulation arm is composed of several independent bending modules in series, which can be configured freely according to the demand of degrees of freedom. Further, each bending module is controlled independently by a parallel platform, which can avoid the mutual interference between the cables of one bending module and another one, improve the position accuracy and simplify the control difficulty of the manipulation arm. To evaluate the proposed method, this work develops a prototype of six-cable-driven continuum robot controlled by 3RPS parallel platforms, and presents some basic kinematic models to describe its function, and then an experimental work characterizing its performance. Experimental results illustrated the importance of increasing the number of cables, the rationality of kinematic models of the continuum robot, and the feasibility of controlling multiple cables by a parallel platform.

Actuators ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 142
Author(s):  
Yong Zhong ◽  
Luohua Hu ◽  
Yinsheng Xu

Traditional rigid robot application in the medical field is limited due to the limited degrees of freedom caused by their material and structure. Inspired by trunk, tentacles, and snakes, continuum robot (CR) could traverse confined space, manipulate objects in complex environment, and conform to curvilinear paths in space. The continuum robot has broad prospect in surgery due to its high dexterity, which can reach circuitous areas of the body and perform precision surgery. Recently, many efforts have been done by researchers to improve the design and actuation methods of continuum robots. Several continuum robots have been applied in clinic surgical interventions and demonstrated superiorities to conventional rigid-link robots. In this paper, we provide an overview of the current development of continuum robots, including the design principles, actuation methods, application prospect, limitations, and challenge. And we also provide perspective for the future development. We hope that with the development of material science, Engineering ethics, and manufacture technology, new methods can be applied to manufacture continuum robots for specific surgical procedures.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
GuoHua Gao ◽  
Pengyu Wang ◽  
Hao Wang

Purpose The purpose of this paper is to present a follow-the-leader motion strategy for multi-section continuum robots, which aims to make the robot have the motion ability in a confined environment and avoid a collision. Design/methodology/approach First, the mechanical design of a multi-section continuum robot is introduced and the forward kinematic model is built. After that, the follow-the-leader motion strategy is proposed and the differential evolution (DE) algorithm for calculating optimal posture parameters is presented. Then simulations and experiments are carried out on a series of predefined paths to analyze the performance of the follow-the-leader motion. Findings The follow-the-leader motion can be well performed on the continuum robots this study proposes in this research. The experimental results show that the deviation from the path is less than 9.7% and the tip error is no more than 15.6%. Research limitations/implications Currently, the follow-the-leader motion is affected by the following factors such as gravity and continuum robot design. Furthermore, the position error is not compensated under open-loop control. In future work, this paper will improve the accuracy of the robot and introduce a closed-loop control strategy to improve the motion accuracy. Originality/value The main contribution of this paper is to present an algorithm to generate follow-the-leader motion of the continuum robot based on DE. This method is suitable for solving new arrangements in the process of following a nonlinear path. Then, it is expected to promote the engineering application of the continuum robot.


2017 ◽  
Vol 40 (11) ◽  
pp. 3263-3272 ◽  
Author(s):  
Minhan Li ◽  
Rongjie Kang ◽  
Shineng Geng ◽  
Emanuele Guglielmino

Continuum robots are suitable for operating in unstructured environments owing to their intrinsic compliance. This paper presents a novel tendon-driven continuum robot equipped with two modules and a compliant backbone formed by helical springs. Each module is driven by four parallel arranged tendons to implement a redundant actuation system that guarantees dexterous motions of the robot. A position feedback controller for the continuum robot is then developed, and a quadratic programming algorithm is incorporated into the controller to achieve a smooth configuration of the robot. Experiments results show that the control method has good trajectory tracking performance against external disturbances.


2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Qinchuan Li ◽  
Jacques Marie Hervé ◽  
Pengcheng Huang

Remote center-of-motion (RCM) parallel manipulators (PMs) are fit for robotized minimally invasive surgery (MIS). RCM PMs with fixed linear actuators have the advantages of high stiffness, reduced moving mass, and higher rigidity and load capacity. However, there are very few available architectures of these types of PMs. Using the Lie group algebraic properties of the set of rigid-body displacements, this paper proposes a new family of RCM PMs with fixed linear actuators for MIS. The general motion with a remote center has four degrees-of-freedom (DOF) and is produced by the in-series concatenation of a spherical S pair and a prismatic P pair and, therefore, is said to be SP equivalent. The SP-equivalent PMs can be used in minimally invasive surgery. First, the kinematic bonds of limb chains and their mechanical generators for SP-equivalent RCM PMs are presented. Limb chains with fixed linear actuators are then derived using the closure of products in subgroups. Structural conditions for constructing an SP-equivalent RCM PM with linear fixed actuators are revealed. Helical pairs are introduced to remove a local rotation and yield a 360-deg-rotation capability of the moving platform. Numerous new architectures with practical potential are presented.


2021 ◽  
Vol 8 ◽  
Author(s):  
Jake A. Childs ◽  
Caleb Rucker

Developing high-strength continuum robots can be challenging without compromising on the overall size of the robot, the complexity of design and the range of motion. In this work, we explore how the load capacity of continuum robots can drastically be improved through a combination of backbone design and convergent actuation path routing. We propose a rhombus-patterned backbone structure composed of thin walled-plates that can be easily fabricated via 3D printing and exhibits high shear and torsional stiffness while allowing bending. We then explore the effect of combined parallel and converging actuation path routing and its influence on continuum robot strength. Experimentally determined compliance matrices are generated for straight, translation and bending configurations for analysis and discussion. A robotic actuation platform is constructed to demonstrate the applicability of these design choices.


2021 ◽  
Author(s):  
Haoran Wu ◽  
Jingjun Yu ◽  
Jie Pan ◽  
Xu Pei

Abstract The inverse kinematics of continuum robot is an important factor to guarantee the motion accuracy. How to construct a concise inverse kinematics model is very essential for the motion control of continuum robot. In this paper, a new method for solving the inverse kinematics of continuum robot is proposed based on the geometric and numerical method. Assumed that the deformation of the continuum robot is Piecewise Constant Curvature model (PCC), the envelope surface of the continuum robot based on single-segment is modeled and calculated. The clustering method is used to calculate the intersection of the curves. Then, a distinct sequence is designed for solving the inverse kinematics of continuum robot, and it is also suitable for the multi-segment continuum robots in space. Finally, the accuracy of the inverse kinematics algorithm is verified by the simulation and numerical experiment. The experiment results illustrate that this algorithm is with higher accuracy compared with the Jacobian iterative algorithm.


Author(s):  
Giuseppe Del Giudice ◽  
Nima Sarli ◽  
Stanley D. Herrell ◽  
Nabil Simaan

The last decade has seen rapid growth in exploring the potential of continuum robots for a variety of surgical applications. The design of these robots requires unique electro-mechanical architectures of actuation units that satisfy operational requirements of precision, workspace, and payload capabilities. This paper presents the task-based design process of a compact nine degrees of freedom actuation unit for transurethral resection of bladder tumor (TURBT). This actuation unit has a unique modular architecture allowing partial decoupling of actuation, force and position sensing in a compact modular format. The derivation of task specifications based on kinematic simulations takes into account workspace, accuracy and force application capabilities for TURBT. Design considerations for supporting modularity, serviceability, sterilization, and compactness are presented. The detailed exposition of the design process serves as a case study that will be helpful for other groups interested in the development and integration of surgical continuum robots.


Author(s):  
Chase G. Frazelle ◽  
Apoorva Kapadia ◽  
Ian Walker

We introduce a novel input device for the teleoperation of extensible continuum robots. As opposed to previous works limited by kinematically dissimilar master devices or restricted Degrees-of-Freedom (DoF), a kinematically similar input device capable of nine degrees-of-freedom is designed and used. The device is capable of achieving configurations identical to a three-section continuum robot and simplifies the control of such manipulators. In this paper, we outline the design of the input device and its construction. Implementation of the new master device and its effectiveness in regulating a physical system is also discussed.


Author(s):  
Cong Wang ◽  
Shineng Geng ◽  
David T Branson ◽  
Chenghao Yang ◽  
Jian S Dai ◽  
...  

Compared to traditional rigid robots, continuum robots have intrinsic compliance and therefore behave dexterously when performing tasks in restricted environments. Although there have been many researches on the design and application of continuum robots, a theoretical investigation of their dexterity is still lacking. In this paper, a two-joint wire-driven continuum robot is utilized to demonstrate dexterity by introducing the concept of orientability taking into account two indices, the accessible ratio and angle of the robot, when its tip reaches a certain task space inside the workspace. Based on the kinematic model, the accessible ratio and angle of the continuum robot are calculated using the Monte-Carlo method. From this, the influence of individual joint lengths on the proposed orientability indices and the optimal joint length are then investigated via an improved particle swarm optimization algorithm. Finally, the presented methods were validated through experiments showing that the use of optimal joint length can increase the accessible ratio and reduce the minimum accessible angle by more than 10° in the task space.


Author(s):  
Yannik Goergen ◽  
Gianluca Rizzello ◽  
Stefan Seelecke ◽  
Paul Motzki

Abstract Due to their unique manipulation capabilities, continuum robots find applications in a variety of different areas, such as medical technology or maintenance and repair. When working with continuum robots, it is often necessary to bend the structure according to complex shapes. This is commonly achieved by arranging several individual modules in series. In this paper, a novel continuum robot concept is presented based on a serial arrangement of SMA (Shape Memory Alloy) wires actuated modules. The key advantage of the described modular continuum robot is the number of connection wires required to control the SMA wires, which is also independent of the number of modules. This feature makes it possible to virtually connect a very large number of serial modules, thus enabling to design continuum robots with arbitrary complexity. After outlining the concept, the mechanical and electrical components required to build one module of such an SMA driven continuum robot are introduced.


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