scholarly journals Kinematics modeling of a two DOFs continuum manipulator with uniform notches

2020 ◽  
Vol 309 ◽  
pp. 05006
Author(s):  
Xiaolong Wang ◽  
Haodong Wang ◽  
Zhijiang Du ◽  
Wenlong Yang

Continuum manipulators have been widely adopted for single-port laparoscopy (SPL). A novel continuum manipulator with uniform notches which has two degrees of freedom (DOFs) is presented in this paper. The arrangement of flexible beams makes it own a higher load capacity. Its kinematic model is coupled with the mechanical model. The comprehensive elliptic integral solution (CEIS) is more practical in the actual deformation of the flexible beams. Based on that method, kinematics modeling is established from the driven space to the Cartesian space. The friction coefficient is an important factor which can affect the kinematic modeling. Therefore, an experimental platform is established to obtain the friction coefficient. The kinematic modeling is verified through the prototype. Experimental results show that the model has high precision.

2015 ◽  
Vol 7 (4) ◽  
Author(s):  
Zhijiang Du ◽  
Wenlong Yang ◽  
Wei Dong

In this paper, the kinematics modeling of a notched continuum manipulator is presented, which includes the mechanics-based forward kinematics and the curve-fitting-based inverse kinematics. In order to establish the forward kinematics model by using Denavit–Hartenberg (D–H) procedure, the compliant continuum manipulator featuring the hyper-redundant degrees of freedom (DOF) is simplified into finite discrete joints. Based on that hypothesis, the mapping from the discrete joints to the distal position of the continuum manipulator is built up via the mechanics model. On the other hand, to reduce the effect of the hyper-redundancy for the continuum manipulator's inverse kinematic model, the “curve-fitting” approach is utilized to map the end position to the deformation angle of the continuum manipulator. By the proposed strategy, the inverse kinematics of the hyper-redundant continuum manipulator can be solved by using the traditional geometric method. Finally, the proposed methodologies are validated experimentally on a triangular notched continuum manipulator which illustrates the capability and the effectiveness of our proposed kinematics for continuum manipulators and also can be used as a generic method for such notched continuum manipulators.


2013 ◽  
Vol 461 ◽  
pp. 278-283 ◽  
Author(s):  
Jiang Hai Zhao ◽  
Xiao Dong Ye ◽  
Wen Huan Qian

Due to the space constraints and obstacles, the traditional industrial manipulator is too difficult to achieve some tasks, such as the gluing for the wing bulkhead of the aircraft and the maintenance for cooling pipes of the nuclear power plant, etc. Continuum manipulator, inspired by the trunk and the tentacle, proves to be very effective for above-mentioned tasks. A novel octopus-like biomimetic robots, is proposed in this paper, which is consisting of continuum joints and discrete joints, and provide a host of benefits, such as the large space of movement, the high flexibility and the heavy load. A novel analytical approach for solving kinematics of the octopus-like arm manipulator with mixed joints is presented in this paper. Based on the bionic mechanism of the continuum manipulator constructed from mixed joints, the robot configuration is established. In this paper, we present a detailed formulation and explanation of a novel kinematic model for the continuum robots with mixed joints. The modeling method based on the Denavit–Hartenberg parameters(also called DH parameters) is used to depict the motion of robot. The robot is comprised of the continuum joint and the rotated joint, so the kinematic model of continuum joint is crucial for constructing that of the whole robot. The continuum joint is equivalent to a section of elastic body, whose D-H parametors can be obtain from the constant-curvature method. Then the forward kinematics of the whole robot can be builded in a D-H frame. Research results will create a new modeling method for the octopus-like continuum manipulators with mixed joints, which can give a new approach for the design on the biomimetic manipulators operating in the unstructured envirement.


2021 ◽  
Vol 21 (2) ◽  
pp. 118-129
Author(s):  
Hasan Dawood Salman ◽  
Mohsin Noori Hamzah ◽  
Sadeq Hussein Bakhy

The kinematics modeling of the robot arm plays an important role in robot control. This paper presents the kinematic model of a three-degree of freedom articulated robot arm, which is designed for picking and placing an application with hand gripper, where a robot has been manufactured for that purpose. The forward kinematic model has been presented in order to determine the end effector’s poses using the Denavit-Hartenberg (DH) convention. For inverse kinematics, an algebraic solution based on trigonometric formulas mixed with geometric method was adopted for a 3 DOF modular manipulator taking into account the existence of a shoulder offset. MATLAB software was used as a tool to simulate and implement the motional characteristics of the robot arm, by creating a 3D visual software package under designing a Graphical User Interface "GUI" with a support simulation from robotic Toolbox (Rtb 10.3). Finally, an electronic interfacing circuit between the GUI program and the robot arm was developed using Arduino microcontroller to control the robot motion. The presented work can be applicable for learning the reality interface design methodology of the other kinds of robot manipulators and achieve a suitable solution for the motional characteristics


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
A. S. Niyetkaliyev ◽  
E. Sariyildiz ◽  
G. Alici

Abstract The robotic shoulder rehabilitation exoskeletons that do not take into consideration all shoulder degrees-of-freedom (DOFs) lead to undesirable interaction forces and cause discomfort to the patient due to the joint axes misalignments between the exoskeleton and shoulder joints. In order to contribute to the solution of this human–robot compatibility issue, we present the kinematic modeling and analysis of a novel bio-inspired 5-DOFs hybrid human–robot mechanism (HRM). The human limbs are regarded as the inner passive restrained links in the proposed hybrid constrained anthropomorphic mechanism. The proposed hybrid mechanism combines serial and parallel manipulators with rigid and cable links enabling a match between human and exoskeleton joint axes. It is designed to cover the whole range of motion of the human shoulder with the workspace free of singularities. The numerical and simulation results from the computer-aided drawing model of the mechanism are presented to demonstrate the validity of the kinematic model, and the kinematic and singularity merits of the proposed mechanism. A three-dimensional printed prototype of the hybrid mechanism was fabricated to further validate the kinematic model and its overall advantages.


Author(s):  
Hao Wang ◽  
GuoHua Gao ◽  
Qixiao Xia ◽  
Han Ren ◽  
LianShi Li ◽  
...  

Purpose The purpose of this paper is to present a novel stretch-retractable single section (SRSS) continuum manipulator which owns three degrees of freedom and higher motion range in three-dimension workspace than regular single continuum manipulator. Moreover, the motion accuracy was analyzed based on the kinematic model. In addition, the experiments were carried out for validation of the theory. Design/methodology/approach A kinematics model of the SRSS continuum manipulator is presented for analysis on bending, rotating and retracting in its workspace. To discuss the motion accuracy of the SRSS continuum manipulator, the dexterity theory was introduced based on the decomposing of the Jacobian matrix. In addition, the accuracy of motion is estimated based on the inverse kinematics and dexterity theory. To verify the presented theory, the motion of free end was tracked by an electromagnetic positioning system. According to the comparison of experimental value and theoretical analysis, the free end error of SRSS continuum manipulator is less than 6.24 per cent in the region with favorable dexterity. Findings This paper presents a new stretch-retractable continuum manipulator that the structure was composed of several springs as the backbone. Thus, the SRSS continuum manipulator could own wide motion range depending on its retractable structure. Then, the motion accuracy character of the SRSS continuum manipulator in the different regions of its workspace was obtained both theoretically and experimentally. The results show that the high accuracy region distributes in the vicinity of the outer boundary of the workspace. The motion accuracy gradually decreases with the motion position approaching to the center of its workspace. Research limitations/implications The presented SRSS continuum manipulator owns three degrees of freedom. The future work would be focused on the two-section structure which will own six degrees of freedom. Practical implications In this study, the SRSS continuum manipulator could be extended to six degrees of freedom continuum robot with two sections that is less one section than regular six degrees of freedom with three single section continuum manipulator. Originality/value The value of this study is to propose a SRSS continuum manipulator which owns three degrees of freedom and could stretch and retract to expend workspace, for which the accuracy in different regions of the workspace was analyzed and validated based on the kinematics model and experiments. The results could be feasible to plan the motion space of the SRSS continuum manipulator for keeping in suitable accuracy region.


2012 ◽  
Vol 605-607 ◽  
pp. 1465-1468
Author(s):  
Shan Le Cai ◽  
Wen Tao Huang ◽  
Li Bin Peng

Put forward a kind of 2 dof parallel fixture. The moving platform of the fixture has two rotational degrees of freedom relative to the fixed platform. Do the institutional analysis and its degree of freedom calculation. Study the kinematics modeling method, and carry out an analysis on forward and inverse solutions of its positions. The new parallel fixture will have wide appli¬ca¬tion in the field of machining.


Author(s):  
Martin Garcia ◽  
Amir Ali Amiri Moghadam ◽  
Ayse Tekes ◽  
Randy Emert

Abstract This paper reports on design, fabrication, and kinematics modeling of a 3D printed soft parallel robot equipped with soft pneumatic actuators. Soft robotics is an emerging field of research which facilitates safe human machine interface. Soft elastomeric actuators made through molding process are one of the key elements of soft robotic systems. However, molding process is tedious and time consuming making the fabrication process undesirable. Recently reported 3D printed soft pneumatic actuators pave the way for manufacturing of novel soft actuators and robots with complex geometries. The current work can be considered as a proof of concept for 3D printing of a soft parallel robot. The robot consists of two soft pneumatic actuators that are connected to two passive links by mean of flexible hinges. The robot has two degrees of freedom and can be used in planar manipulation tasks. Moreover, a number of robots can be configured to operate in a cooperative manner to increase the manipulation dexterity. A kinematic model is developed to simulate the motion of robot end-effector. Through application of the kinematic model it has been shown that the robot is capable of following any planar trajectories within its workspace. Also, pseudo-rigid-body model (PRBM) is used to develop a dynamic model of the soft robot to more accurately predict the robot interaction with its environment and also develop advanced control system for robust position control of the robot.


2018 ◽  
Vol 224 ◽  
pp. 02034 ◽  
Author(s):  
Aleksey Kabanov ◽  
Aleksey Balabanov

This paper considers the anthropomorphic manipulator kinematics modeling problem. The considered anthropomorphic robot SAR-400 manipulator with five-fingered gripper has twelve degrees of freedom. In the paper the robot SAR-400 arm kinematic model and the simulation results are presented.


2018 ◽  
Vol 15 (5) ◽  
pp. 172988141880384 ◽  
Author(s):  
Jonqlan Lin ◽  
Chi Ying Wu ◽  
Julian Chang

Cable-driven parallel robots comprise driven actuators that allow controlled cables to act in parallel on an end-effector. Such a robotic system has a potentially large reachable workspace, large load capacity, high payload-to-weight ratio, high reconfigurability, and low inertia, relative to rigid link serial and parallel robots. In this work, a multi-degrees-of-freedom cable-suspended robot that can carry out pick-and-place tasks in large workspaces with heavy loads is designed. The proposed cable-driven parallel robot is composed of a rigid frame and an end-effector that is suspended from eight cables—four upper cables and four lower cables. The lengths of the cables are computed from the given positions of the suspended end-effector using a kinematic model. However, most multi-cable-driven robots suffer from interference among the cables, requiring a complex control methodology to find a target goal. Owing to this issue with cable-driven parallel robots, the whole control structure decomposes positioning control missions and allocates them into upper level and lower level. The upper level control is responsible for tracking the suspended end-effector to the target region. The lower level control makes fine positional modifications. Experimental results reveal that the hybrid control mode notably improves positioning performance. The wide variety of issues that are considered in this work apply to aerostats, towing cranes, locomotion interfaces, and large-scale manufacturing that require cable-driven parallel robots.


Author(s):  
Ibrahim Niyazi Bodur

Abstract In this paper an improved kinematic modeling method is developed which is applicable to both open and closed kinematic chain topology mechanisms. This methodology is based on relative coordinate frames assigned to the individual links and joints, and the 4 × 4 homogenous transformation matrices between these relative coordinate frames. The homogenous transformation matrices can accommodate the full six degrees-of-freedom necessary in 3-D space. Therefore, this method enables one to develop a kinematic model that corresponds to the actual mechanism. In doing so, the effect of the links and joints are considered separately which will aid one in conceptual and actual development of the model. The method is applied to a Cincinnati-Milacron T3 robot which is a six degree-of-freedom robot with a 3-D spatial serial configuration mechanism made of binary links and one degree-of-freedom joints connecting the links. The results obtained from the methodology developed here are compared to the results of a popular method developed by another researcher. The methodology developed in this paper is applicable to higher degree-of-freedom joints, up to the full six degrees-of-freedom. It can also be applied to multi-loop mechanisms with the accompanying increase in the complexity of the model. This method helps to reduce the complexity of the problem when one uses the kinematic model of a mechanism in an interference checking, dynamic modeling and simulation, and link flexibility problem. Finally, it is shown that the use of 4 × 4 homogenous transformation matrices do not increase the calculational complexity of the problem appreciably.


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