Workspace Analysis of Tendon-Driven Continuum Robots Based on Mechanical Interference Identification

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Kun Cao ◽  
Rongjie Kang ◽  
David T. Branson ◽  
Shineng Geng ◽  
Zhibin Song ◽  
...  
Keyword(s):  
Kinematic Model ◽  
Superposition Method ◽  
Continuum Robots ◽  
Bending Angle ◽  
Scanning Method ◽  
Actuation System ◽  
Workspace Analysis ◽  
Continuum Robot ◽  
Mechanical Interference ◽  
Backbone Structure

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.

Jacobian Matrix of a Novel Continuum Robot for Search and Rescue

2013 ◽  
Vol 303-306 ◽  
pp. 1695-1701 ◽  
Author(s):  
Guang Zhu Meng ◽  
Ling Yu Sun ◽  
Ping Peng ◽  
Xian Chun Meng ◽  
Hong Mei Wang ◽  
...  
Keyword(s):  
Jacobian Matrix ◽  
Kinematic Model ◽  
Search And Rescue ◽  
Chain Rule ◽  
Continuum Robots ◽  
Actuation System ◽  
Continuum Robot ◽  
Forward Kinematic

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.

Follow-the-leader motion strategy for multi-section continuum robots based on differential evolution algorithm

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
GuoHua Gao ◽  
Pengyu Wang ◽  
Hao Wang
Keyword(s):  
Differential Evolution ◽  
Kinematic Model ◽  
Differential Evolution Algorithm ◽  
Open Loop ◽  
Continuum Robots ◽  
Content Type ◽  
Loop Control ◽  
Continuum Robot ◽  
Motion Strategy ◽  
The Continuum

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.

scholarly journals Micrometer Positioning Accuracy With a Planar Parallel Continuum Robot

2021 ◽  
Vol 8 ◽  
Author(s):  
Benjamin Mauzé ◽  
Guillaume J. Laurent ◽  
Redwan Dahmouche ◽  
Cédric Clévy
Keyword(s):  
Kinematic Model ◽  
High Accuracy ◽  
Circular Path ◽  
Continuum Robots ◽  
Continuum Robot ◽  
Good Potential ◽  
Proper Estimation ◽  
Articulated Robots ◽  
Automatic Positioning ◽  
Influential Parameters

Parallel Continuum Robots (PCR) have several advantages over classical articulated robots, notably a large workspace, miniaturization capabilities and safe human-robot interactions. However, their low accuracy is still a serious drawback. Indeed, several conditions have to be met for PCR to reach a high accuracy, namely: a repeatable mechanical structure, a correct kinematic model, and a proper estimation of the model’s parameters. In this article, we propose a methodology that allows reaching a micrometer accuracy with a PCR. This approach emphasizes the importance of using a repeatable continuum mechanism, identifying the most influential parameters of an accurate kinematic model of the robot and precisely measuring them. The experimental results show that the proposed approach allows to reach an accuracy of 3.3 µm in position and 0.5 mrad in orientation over a 10 mm long circular path. These results push the current limits of PCR accuracy and make them good potential candidates for high accuracy automatic positioning tasks.

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
Keyword(s):  
Control Method ◽  
Programming Algorithm ◽  
Redundant Actuation ◽  
External Disturbances ◽  
Continuum Robots ◽  
Helical Springs ◽  
Actuation System ◽  
Continuum Robot ◽  
And Control ◽  
The Continuum

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.

Quasi-static modeling of a novel growing soft-continuum robot

2019 ◽  
pp. 027836491989343
Author(s):  
Cem Tutcu ◽  
Bora A. Baydere ◽  
Seref K. Talas ◽  
Evren Samur
Keyword(s):  
Kinematic Model ◽  
Potential Method ◽  
Static Model ◽  
Model Parameters ◽  
Continuum Robots ◽  
End Effector ◽  
Precise Control ◽  
Proposed Model ◽  
Continuum Robot ◽  
Static Modeling

Soft-continuum robots attract researchers owing to their advantages over rigid-bodied robots such as adaptation of the flexible structure to tortuous environments, and compliant contact mechanics. The need for new modeling methods to attain precise control for such systems has emerged from the recent rapid progress in soft robotics. This article presents a quasi-static model for a growing soft-continuum robot that is propelled via thin-walled inflated tubes, and steered by the difference between tube lengths. Therefore, the robot shaft is modeled as a series of inflated beams under deformation. A quasi-static model coupled with a kinematic model is developed to accurately position the end effector while accounting for the inflated beam stiffness and end-effector loads. The proposed model calculates control parameters, namely tube lengths and tendon tensions required to maintain the end effector at a certain position. Tip deflection due to end-effector loading is calculated and kinematic model inputs are updated to correct positioning error caused by shaft deformation. The model is simulated for the soft-continuum robot moving on a path to show the change in model parameters for various end-effector positions. Results demonstrate the significance of including pressurized tube stiffness in the model for growing robots of similar type. Second, the need for tendons in addition to pneumatic actuation is emphasized for accurate positioning of the end effector under loading. The proposed model offers a potential method for simulation and control of similar growing soft-continuum robots presented in the literature.

scholarly journals Leveraging Geometry to Enable High-Strength Continuum Robots

2021 ◽  
Vol 8 ◽  
Author(s):  
Jake A. Childs ◽  
Caleb Rucker
Keyword(s):  
3D Printing ◽  
Load Capacity ◽  
High Strength ◽  
Torsional Stiffness ◽  
High Shear ◽  
Continuum Robots ◽  
Continuum Robot ◽  
Backbone Structure ◽  
Thin Walled ◽  
Compliance Matrices

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.

An Origami Parallel Structure Integrated Deployable Continuum Robot

2015 ◽  
Author(s):  
Ketao Zhang ◽  
Chen Qiu ◽  
Jian S. Dai
Keyword(s):  
Translational Motion ◽  
Kinematic Model ◽  
Parallel Structure ◽  
Continuum Robots ◽  
Helical Springs ◽  
Parallel Structures ◽  
Driven System ◽  
Continuum Robot ◽  
Motion Characteristics ◽  
Novel Design

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.

scholarly journals Task space-based orientability analysis and optimization of a wire-driven continuum robot

2019 ◽  
Vol 233 (23-24) ◽  
pp. 7658-7668
Author(s):  
Cong Wang ◽  
Shineng Geng ◽  
David T Branson ◽  
Chenghao Yang ◽  
Jian S Dai ◽  
...  
Keyword(s):  
Particle Swarm Optimization Algorithm ◽  
Kinematic Model ◽  
Task Space ◽  
Continuum Robots ◽  
Swarm Optimization ◽  
The Monte Carlo Method ◽  
Continuum Robot ◽  
Two Indices ◽  
Joint Length ◽  
The Continuum

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.

An Extensible Continuum Robot With Integrated Origami Parallel Modules

2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Ketao Zhang ◽  
Chen Qiu ◽  
Jian S. Dai
Keyword(s):  
Translational Motion ◽  
Kinematic Model ◽  
Parallel Structure ◽  
Continuum Robots ◽  
Helical Springs ◽  
Compression Spring ◽  
Driven System ◽  
Continuum Robot ◽  
Motion Characteristics ◽  
Novel Design

This paper presents a novel design of extensible continuum robots in light of origami-inspired folding techniques. The design starts from a modularized crease pattern, which consists of two triangular bases and three waterbomb bases, and generates a folding process for creating an origami waterbomb parallel structure. This further progresses to generating a compliant module with the origami parallel structure and a helical compression spring. A novel extensible continuum robot with the integrated compliant parallel modules is then proposed to imitate not only the bending motion but also the contraction of continuum creatures in nature. Mapping the origami parallel structure to an equivalent kinematic model, the motion characteristics of the origami structure are explored in terms of kinematic principles. The analysis reveals the mixed rotational and translational motion of the origami parallel module and the virtual axes for yaw and pitch motions. Following kinematics of the proposed continuum robot and features of the integrated helical spring in each module, three actuation schemes and resultant typical working phases with a tendon-driven system are presented. The design and analysis are then followed by a prototype of the extensible continuum robot with six integrated compliant modules connected in serial. The functionality of the proposed continuum robot with the origami parallel structure as its skeleton and the helical springs as the compliant backbone is validated by experimental results.

scholarly journals Development of Continuum Robot Arm and Gripper for Harvesting Cherry Tomatoes

2019 ◽  
Author(s):  
Azamat Yeshmukhametov ◽  
Koichi Koganezawa ◽  
Zholdas Buribayev ◽  
Yedilkhan Amirgaliyev ◽  
Yoshio Yamamoto
Keyword(s):  
Machine Learning ◽  
Recognition System ◽  
Stem Cutting ◽  
Robot Arm ◽  
Design And Development ◽  
Challenging Issue ◽  
Continuum Robot ◽  
Unstructured Environment ◽  
Backbone Structure ◽  
Cherry Tomatoes

Designing and development of agricultural robot is always a challenging issue, because of robot intends to work an unstructured environment and at the same time, it should be safe for the surrounded plants. Therefore, traditional robots cannot meet the high demands of modern challenges, such as working in confined and unstructured workspaces. Based on current issues, we developed a new tomato harvesting wire-driven discrete continuum robot arm with a flexible backbone structure for working in confined and extremely constrained spaces. Moreover, we optimized a tomato detaching process by using newly designed gripper with passive stem cutting function. Moreover, by designing the robot we also developed ripe tomato recognition by using machine learning. This paper explains the proposed continuum robot structure, gripper design, and development of tomato recognition system.

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