Kinematic and dynamic performance investigations of asymmetric (U-shape fixed base) planar parallel manipulators
01 Aug 2018-Robotica (Cambridge University Press (CUP))-Vol. 36, Iss: 8, pp 1111-1143
TL;DR: A comparative dynamic performance analysis of these top-three U-shape fixed base PPMs in terms of dynamic driving performance measures, and energy requirements for three different (fixed base size of the manipulators) aspect ratios under two different loading conditions is presented.
Abstract: In this paper, a new family of 3-degree-of-freedom planar parallel manipulators (PPMs), namely U-shape fixed base PPMs starting with an active prismatic joint on each leg, is proposed. In order to identify the best manipulators of this family, comparative kinematic and dynamic performance studies are performed. The kinematic performances are quantified through the local performance index, namely the kinematic isotropy. From the kinematic isotropy analysis results, it is observed that P PR- P RP- P RP, P RP- P RP- P RP and P RR- P RP- P RP configurations have better kinematic design aspects compared to other configurations of this family of U-shape fixed base parallel configurations. Further, from the workspace analysis, it is observed that the P PR- P RP- P RP configuration has a higher value of workspace to the total area required ratio compared to other configurations. This paper also presents a comparative dynamic performance analysis of these top-three U-shape fixed base configurations in terms of dynamic driving performance measures, and energy requirements for three different (fixed base size of the manipulators) aspect ratios under two different loading conditions. From the analyses results, it is perceived that the P RP- P RP- P RP configuration is requiring lower energy and dynamic driving performances than others. These analyses are done with the help of multi-body dynamic software, namely MSC ADAMS, and the results are validated through the help of real-time experiments conducted on in-house fabricated prototypes of these three PPMs. In specific, the energy consumption is measured and compared in this study. Experimental results demonstrated that the P RP- P RP- P RP manipulator displays a considerably better performance in terms of minimum energy requirement.
01 Apr 2021
TL;DR: This study presents the kinematic design of smart linearly actuated family of U-shape base planar parallel robotic manipulator, and the PPR-PRP-PRR manipulator was found to possess highest experimental workspace than other configurations.
Abstract: The applications of lightweight planar parallel robotic manipulators are increasing enormously because of its various desirable characteristics such as low weight, lower inertia and higher stiffness Higher accelerations and accuracies can be achieved in planar parallel manipulators Also, shape memory alloy restoration technique (SMART)-based linear actuators are replacing huge and bulky linear actuators This study presents the kinematic design of smart linearly actuated family of U-shape base planar parallel robotic manipulator With the aid of solid modelling software, different available configurations were modelled and their workspace was analysed The developed 3-DOF motion stages (18 unique configurations) were fabricated using fused deposition modelling process, and the top three configurations having higher workspace were further experimented It is interesting to observe that the actual or experimental workspace of a particular manipulator configuration is further minimised from the predicted or feasible workspace It is due to the presence of passive links, singularities, friction between the parts, heat dissipation, force distribution, stiffness, etc The present study depicts the experimental workspace of the top three configurations, namely PPR-PRP-PRR, PRP-PPR-PRP and PRP-PPR-PRR Since none of the experimental workspace observed is equal or higher than the model workspace, an efficiency loss in terms of workspace reduction was calculated to understand the acceptability of the configurations in different domains Apart from the loss, the result disclosed that the actual workspace of all the manipulators was within the feasible workspace domain of mobile platform The PPR-PRP-PRR manipulator was found to possess highest experimental workspace than other configurations Note: P, P, and R refer to active prismatic, passive prismatic and passive revolute joints respectively
TL;DR: A new procedure to calculate principal directions is presented and contrasted with two of the most common procedures employed in the field, in order to understand their underlying concepts and, therefore, gain a deeper understanding of the physical situation.
Abstract: Assume that the end-effector of a serial mechanism with n-degrees of freedom arrives at the position p0, where it can change arbitrarily the direction of its movement. The physical conditions imply that this change in direction also alters its velocity. The kinematic performance ellipse represents the velocities according to the new direction of the system, and thus solving the problem of which direction will correspond to a maximum or minimum (principal directions) magnitude of the corresponding velocity. In this paper, a new procedure to calculate these principal directions is presented and contrasted with two of the most common procedures employed in the field. All three procedures are considered in some detail, in order to understand their underlying concepts and, therefore, gain a deeper understanding of the physical situation. They are all proved in standard examples.
TL;DR: In this article , the authors presented a comprehensive comparison study on the dynamic performances of three planar 3DOF parallel manipulators (PPMs): 3-RRR, 3-PRR, and 3-RPR.
Abstract: This paper presents a comprehensive comparison study on the dynamic performances of three planar 3-DOF parallel manipulators (PPMs): 3-RRR, 3-PRR, and 3-RPR. In this research work, the discrete time transfer matrix method (DT-TMM) is employed for developing dynamic models of the planar parallel manipulators. Numerical simulations using the virtual work principle and ADAMS 2016 software are performed to verify the DT-TMM dynamic model of PPMs. Numerous dynamic performance indices, including dynamic dexterity, the power requirement, energy transmission efficiency, and the joint force/torque margin, are proposed to compare the dynamic performance of three PPMs under the general circular and linear trajectories. The comprehensive analyses and comparisons show that: (1) the 3-RRR PPM has advantages in terms of a circular trajectory, offering the best dynamic dexterity performance, the smallest power requirement, and the second-highest energy transfer efficiency; (2) the 3-PRR PPM performs best in terms of a linear trajectory, offering the best dynamic dexterity, the smallest power requirement range, and the best drive performance; and (3) the 3-RPR PPM has the highest energy transfer efficiency and demonstrates better dynamic performance in a circular trajectory compared to a linear trajectory.
19 Dec 2016
TL;DR: In this article, the authors compared the isotropy, manipulability, stiffness and payload aspects of the 18 possible square shape/U-base 3 degree of freedom planar parallel manipulators.
Abstract: 1. Comparative kinematic performance study on isotropy, manipulability, stiffness and payload aspects of the 18 possible square shape/U-base 3 degree of freedom planar parallel manipulators is performed. This study helps the designer to identify the best/feasible planar parallel manipulator for the given task. It can also be used as a tool for designing a planar motion platform (x, y and motions) as per the designer’s requirement on the basis of their applications. 2. Two new/improved motion control schemes namely an improved sliding mode controller and a PID-like fuzzy logic controller are introduced to improve the overall motion control performance in terms of their robustness and adaptive aspects. 3. Development of a four axis vertical milling machine with an extension of the proposed manipulator (PPR-PRP-PRP) as a work table and its performance is demonstrated at different working conditions.
01 Aug 2020
TL;DR: In this article, a measure of manipulability of robotic mechanisms in positioning and orienting end-effectors has been proposed and the best postures of various types of manipulators are given, and a four degree-of-freedom finger is considered from the viewpoint of the measure.
Abstract: This paper discusses the manipulating ability of robotic mechanisms in positioning and orienting end-effectors and proposes a measure of manipulability. Some properties of this measure are obtained, the best postures of various types of manipulators are given, and a four-degree-of-freedom finger is considered from the viewpoint of the measure. The pos tures somewhat resemble those of human arms and fingers.
31 Jul 2000
TL;DR: This book presents a complete synthesis of the latest results on the possible mechanical architectures, analysis and synthesis of this type of mechanism, Parallel robots, which are becoming increasingly popular in the field of machine-tool industry.
Abstract: Parallel robots are closed-loop mechanisms presenting very good performances in terms of accuracy, velocity, rigidity and ability to manipulate large loads. They have been used in a large number of applications ranging from astronomy to flight simulators and are becoming increasingly popular in the field of machine-tool industry. This book presents a complete synthesis of the latest results on the possible mechanical architectures, analysis and synthesis of this type of mechanism. It is intended to be used by students (with over 150 exercises and numerous internet addresses), researchers (with over650 references and anonymous ftp access to the code of some algorithms presented in this book) and engineers (for which practical results, mistakes to avoid,and applications are presented). Since the publication of the first edition (2000) there has been an impressive increase in terms of study and use of this kind of structure that are reported in this book. This second edition has been completely overhauled. The initial chapter on kinematics has been split into Inverse Kinematics and Direct Kinematics. A new chapter on calibration was added. The other chapters have also been rewritten to a large extent.The reference section has been updated to include around 45% new works that appeared after the first edition.
TL;DR: A unifying framework for the analysis and control of robotic systems is produced, beginning with an analysis of inertial prop erties based on two models that independently describe the mass and inertial characteristics associated with linear and angular motions.
Abstract: Consideration of dynamics is critical in the analysis, design, and control of robot systems. This article presents an extensive study of the dynamic properties of several important classes of robot...
01 Jan 2008
TL;DR: This dissertation aims to provide a history of web exceptionalism from 1989 to 2002, a period chosen in order to explore its roots as well as specific cases up to and including the year in which descriptions of “Web 2.0” began to circulate.
Abstract: Description based on online resource; title from PDF title page (ebrary, viewed October 11, 2013).
TL;DR: This paper presents geometrical algorithms for the determination of various workspaces of planar parallel manipulators and one of them is used to illustrate the algorithms.
Abstract: This paper presents geometrical algorithms for the determination of various workspaces of planar parallel manipulators. Workspaces are defined as regions which can be reached by a reference point C located on the mobile platform. First, the maximal workspace is determined as the region which can be reached by point C with at least one orientation. From the above regions, the inclusive workspace, i.e., the region which can be attained by point C with at least one orientation in a given range, can be obtained. Then, the total orientation workspace, i.e., the region which can be reached by point C with every orientation of the platform in a given range, is determined. Three types of planar parallel manipulators are described and one of them is used to illustrate the algorithms.
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