Design and control of a tendon-driven 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.

Author(s):  
Azamat Nurlanovich Yeshmukhametov ◽  
Koichi Koganezawa ◽  
Zholdas Buribayev ◽  
Yedilkhan Amirgaliyev ◽  
Yoshio Yamamoto

Purpose The purpose of this paper is to present a novel hybrid pre-tension mechanism for continuum manipulators to prevent wire slack and improve continuum robot payload capacity, as well as to present a new method to control continuum manipulators’ shape. Design/methodology/approach This research explains the hardware design of a hybrid pre-tension mechanism device and proposes a mathematic formulation wire-tension based on robot design. Also, the wire-tension control method and payload estimation model would be discussed. Findings Wire-tension is directly related to the continuum manipulators’ rigidity and accuracy. However, in the case of robot motion, wires lose their tension and such an issue leads to the inaccuracy and twist deformation. Therefore, the proposed design assists in preventing any wire slack and derailing the problem of the wires. Originality/value The novelty of this research is proposed pre-tension mechanism device design and control schematics. Proposed pre-tension mechanism designed to maintain up to eight wires simultaneously.


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.


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.


Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 634 ◽  
Author(s):  
Yang Li ◽  
Zongxia Jiao ◽  
Zimeng Wang

In order to provide a simplified and low-cost solution of the terminal for a distributed actuation system, this paper proposes an electro-hydrostatic actuator (EHA) based on the linear drive principle. The proposed actuator is directly driven by a linear pump with a collaborative rectification mechanism, whose performance relies on the collaboration of the internal two units. A pair of linear oscillating motors are employed to drive the two pump units respectively. The control of the actuator is based on the modulation of the oscillating amplitude, frequency, and phase difference of the two motors. The advantage of this actuator is that no more valve control is needed to rectify the linear pump besides the high efficiency of the direct pump drive. In this paper, both schematic and detailed structure of the actuator is presented. The kinematic and dynamic characteristics are analyzed and modeled, based on which the control method is proposed. The experiments verify the validity of the actuator structure and control.


2013 ◽  
Vol 303-306 ◽  
pp. 1695-1701 ◽  
Author(s):  
Guang Zhu Meng ◽  
Ling Yu Sun ◽  
Ping Peng ◽  
Xian Chun Meng ◽  
Hong Mei Wang ◽  
...  

In this paper, a novel continuum robot for search and rescue is presented. A forward kinematic model is derived by product of exponentials formula, compare with conventional D-H method, this method is concise and simplicity. Finally, based on the differential kinematics using the chain rule, the overall Jacobian of the robot is established. This approach can be generally applied to various continuum robots, regardless of the specific actuation system used.


2020 ◽  
pp. 107754632097116
Author(s):  
Berkan Hizarci ◽  
Zeki Kiral

This study deals with the vibration reduction of a cantilever beam using air-jet thruster actuators controlled by the particle swarm optimized quasi bang–bang controller. In this study, the finite element model of a cantilever beam with the lumped mass of actuators is formed for the numerical simulations. Furthermore, the first-order plus dead time transfer function of the air-jet thruster actuator is found between the inlet pressure and the thrust. The quasi bang–bang control is proposed to suppress vibrations on the beam with impulsive air-jet pulses. The optimal location of the actuators and control parameters are determined with parametric study and particle swarm optimization, respectively. The performance of the control method is measured with the experiments of initial displacement, the presence of tip masses, and external disturbances. According to all results obtained in this study, it has been observed that the air-jet pulses successfully and rapidly attenuate vibration on the cantilever beam with the quasi bang–bang controller.


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.


2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Kun Cao ◽  
Rongjie Kang ◽  
David T. Branson ◽  
Shineng Geng ◽  
Zhibin Song ◽  
...  

Continuum robots have excited increasing attention and efforts from the robotic community due to their high dexterity and safety. This paper proposes a design for a type of multimodule continuum robot equipped with an elastic backbone structure and tendon-driven actuation system. The kinematic model of the robot is formulated where the maximum bending angle of a module is obtained by identifying the interference between the backbone structure and the tendons. A superposition method is then used to determine the configuration space of the robotic module. Finally, an approximation method is presented to estimate the workspace of the tendon-driven continuum robot that reduces the computational complexity in comparison with the previously used scanning method. Experiments are provided to validate the proposed methods.


Author(s):  
Ketao Zhang ◽  
Chen Qiu ◽  
Jian S. Dai

This paper presents a novel design for continuum robots in light of origami inspired folding techniques. The work of the present paper starts from design of a crease pattern, which consists of two triangular bases and three waterbomb bases, and folding process for creating an origami parallel structure in 3D from the crease pattern in 2D. Mapping the origami parallel structure to an equivalent kinematic model, the motion characteristics of the origami structure are unraveled in terms of kinematic principles. The analysis reveals that mixed rotational and translational motion of the origami parallel structure enables both axial contraction and bending motion. A novel multi-section continuum robot with integrated origami parallel structures and bias elements is then proposed to imitate not only bending motion but also contraction of continuum apparatus in nature. According to kinematics of the proposed continuum robot and features of the embedded helical spring in each module, three actuation schemes and their enabled two typical working phases with a tendon driven system are presented. A prototype of the continuum robot with six modules connected in serial is produced and tested. The functionality of the proposed continuum robot by integrating the origami parallel structure as its skeleton and helical springs as the compliant backbone is validated by the preliminary experimental results.


2010 ◽  
Vol 118-120 ◽  
pp. 640-644
Author(s):  
Jian Xin Liu ◽  
Yu Liu ◽  
Ping Tan

This paper presents a kind of all-digital integrated hydraulic actuator (IHA) unit to drive heavy load object without centralized oil tank. In order to improve the control quality of the actuation system while eliminating or reducing the disturbance, and also to solve the problem of flow rate mismatch existed in IHA with single-rod cylinder actuator, a fuzzy PID PWM controller is suggested. Simulations on the integrated hydraulic actuator unit are carried out to evaluate the effectiveness of the proposed control method when applied to hydraulic systems with various external disturbances encountered in real working conditions. Simulation results are discussed and some conclusions are given.


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