Kinematics Modeling of a Family of Pure Translational 3-P^UR Parallel Linear Manipulators

Author(s):  
Giovanni Boschetti ◽  
Roberto Caracciolo ◽  
Alberto Trevisani

This paper introduces a simplified kinematic model for a family of parallel linear manipulators with three degrees of freedom of pure translation. The P^UR topology of the limbs and the adjustable layout of the linear actuators are the main characteristics of such a family. The analytical solutions of the forward and inverse position and velocity kinematics are presented. Then the variations of the manipulator features in terms of workspace and performance indexes are investigated as functions of the actuators arrangement.

Author(s):  
Sunil Kumar Agrawal ◽  
Siyan Li ◽  
Glen Desmier

Abstract The human spine is a sophisticated mechanism consisting of 24 vertebrae which are arranged in a series-chain between the pelvis and the skull. By careful articulation of these vertebrae, a human being achieves fine motion of the skull. The spine can be modeled as a series-chain with 24 rigid links, the vertebrae, where each vertebra has three degrees-of-freedom relative to an adjacent vertebra. From the studies in the literature, the vertebral geometry and the range of motion between adjacent vertebrae are well-known. The objectives of this paper are to present a kinematic model of the spine using the available data in the literature and an algorithm to compute the inter vertebral joint angles given the position and orientation of the skull. This algorithm is based on the observation that the backbone can be described analytically by a space curve which is used to find the joint solutions..


2016 ◽  
Vol 8 (4) ◽  
Author(s):  
Samer Alfayad ◽  
Ahmad M. Tayba ◽  
Fethi B. Ouezdou ◽  
Faycal Namoun

This paper deals with a research work that aims to develop a new three degrees-of-freedom (DoF) hybrid mechanism for humanoid robotics application. The proposed hybrid mechanism can be used as a solution not only for several modules in humanoid robots but also for other legged robots such as quadrupeds and hexapods. Hip and shoulder mechanisms are taken as examples in this paper; torso and spine mechanisms, too, can be based on the proposed solutions. In this paper, a detailed analysis of the required performances of the hip and shoulder mechanisms is first carried out. Then, using a kinematic synthesis, a novel solution for the hip mechanism is proposed based on one rotary and two linear actuators. Improving this solution allows us to fulfill the requirements induced by the large motion ranges of the shoulder module, leading to a new management of the linear actuators contributions in the motion/force achievement process. Kinematic and geometrical models of a generic hybrid mechanism are achieved and used to get the optimized solutions of both hybrid mechanisms addressed in this paper.


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 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.


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.


1995 ◽  
Vol 117 (2A) ◽  
pp. 343-345 ◽  
Author(s):  
S. K. Agrawal ◽  
Glen Desmier ◽  
Siyan Li

This paper describes a three-degrees-of-freedom parallel-actuated wrist mechanism developed at Ohio University. This mechanism is capable of pointing an axis within a cone from the nominal position. The mechanism allows unlimited rotation about the pointing axis. Experiments were conducted to validate the kinematic model of the designed wrist.


Author(s):  
Dan Zhang ◽  
Zhen Gao ◽  
Beizhi Li

A new compliant parallel micromanipulator is proposed in this paper. The manipulator has three degrees of freedom (DOF) and can generate motions in a microscopic scale. It can be used for biomedical engineering and fiber optics industry. In the paper, the detailed design of the structure is first introduced, followed by the kinematic analysis and performance evaluation. Second, a finite-element analysis of resultant stress, strain, and deformations is evaluated based upon different inputs of the three piezoelectric actuators. Finally, the genetic algorithms and radial basis function networks are implemented to search for the optimal architecture and behavior parameters in terms of global stiffness, dexterity and manipulability.


2018 ◽  
Vol 15 (1) ◽  
pp. 172988141875577 ◽  
Author(s):  
Jorge Curiel Godoy ◽  
Ignacio Juárez Campos ◽  
Lucia Márquez Pérez ◽  
Leonardo Romero Muñoz

This article presents the principles upon which a new nonanthropomorphic biped exoskeleton was designed, whose legs are based on an eight-bar mechanism. The main function of the exoskeleton is to assist people who have difficulty walking. Every leg is based on the planar Peaucellier–Lipkin mechanism, which is a one degree of freedom linkage. To be used as a robotic leg, the Peaucellier–Lipkin mechanism was modified by including two more degrees of freedom, as well as by the addition of a mechanical system based on toothed pulleys and timing belts that provides balance and stability to the user. The use of the Peaucellier–Lipkin mechanism, its transformation from one to three degrees of freedom, and the incorporation of the stability system are the main innovations and contributions of this novel nonanthropomorphic exoskeleton. Its mobility and performance are also presented herein, through forward and inverse kinematics, together with its application in carrying out the translation movement of the robotic foot along paths with the imposition of motion laws based on polynomial functions of time.


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.


2021 ◽  
Vol 33 (1) ◽  
pp. 141-150
Author(s):  
Takashi Kei Saito ◽  
Kento Onodera ◽  
Riku Seino ◽  
Takashi Okawa ◽  
Yasushi Saito ◽  
...  

We designed a new telescopic manipulator that uses a clustered elastic convex tape. The manipulator has an ultra-wide expansion range and toughness against mechanical stress. Compared to conventional linear actuators, our convex-type manipulators have high extension range and are very lightweight. Moreover, they are compact when rolled up. The telescopic manipulators designed in the previous study had insufficient output due to structural problems and were unstable. In this study, we report a Type-K telescopic manipulator mechanism (Makijaku-Ude Type-K), which is a redesigned manipulator that can be easily used with a 300-N class power, and applied the mechanism to a three degrees-of-freedom spatial parallel-mechanism robot.


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