KASITS: A Graphical User Interface for Kinematic Analysis and Synthesis of Five-Bar Linkage with Prismatic Joint

In this paper, a novel graphical user interface is developed for kinematic analysis and synthesis of five-bar linkage with prismatic joint, named KASITS. This interface has two menus that the users can freely select, namely for analysis and synthesis. In the analysis menu, the direct kinematics are derived to visually depict the overall workspace of the mechanism. Within this workspace, the singularity curves are plotted. In the synthesis menu, the value of design parameters is obtained for a given trajectory. An optimization is employed based on Pareto optimal solutions. The demonstration is provided to guide the users better

Kinematic and dynamic analysis of spatial six degree of freedom parallel structure manipulator

Thesis (Master)--Izmir Institute of Technology, Mechanical Engineering, Izmir, 2003Includes bibliographical references (leaves: 63-69)Text in English; Abstract: Turkish and Englishviii, 86 leavesThis thesis covers a study on kinematic and dynamic analysis of a new type of spatial six degree of freedom parallel manipulator. The background for structural synthesis of parallel manipulators is also given. The structure of the said manipulator is especially designed to cover a larger workspace then well-known Stewart Platform and its derivates. The main point of interest for this manipulator is its hybrid actuating system, consisting of three revolute and three linear actuators.Kinematic analysis comprises forward and inverse displacement analysis. Screw Theory and geometric constraint considerations were the main tools used. While it was possible to derive a closed-form solution for the inverse displacement analysis, a numerical approach was used to solve the problem of forward displacement analysis. Based on the results of the kinematic analysis, a rough workspace study of the manipulator is also accomplished. On the dynamics part, attention has been given on inverse dynamics problem using Lagrange-Euler approach.Both high and lower level software were heavily utilized. Also computer software called .CASSoM. and .iMIDAS. are developed to be used for structural synthesis and inverse displacement analysis. The major contribution of the study to the scientific community is the proposal of a new type of parallel manipulator, which has to be studied extensively regarding its other interesting properties

A Maple Toolchain for Rigid Body Dynamics of Serial, Hybrid and Parallel Robots

A new Maple toolchain for generating rigid body dynamics in symbolic form for robot manipulators is presented. The peculiarity compared to existing tools lies in the framework of Bash scripts controlling the full workflow of the toolchain with a high degree of automation. The optimized Matlab code generated by Maple is automatically converted to function files with proper documentation and input assertions. This renders manual post-processing of the results unnecessarily. The focus of the paper is on the implemented unit-testing framework according to the method of test-driven development. By providing the test framework together with the generated code in a stand-alone version, a good test coverage and a good software quality can be achieved. The results of the open source project provide a basis for dynamics simulations for robot dimensional synthesis or in model-based control of robot manipulators in research or in industrial context. The general software approach can be applied to other fields where theoretical models are derived with Maple

On the design of multi-platform parallel mechanisms

Parallel mechanisms have been examined in more and more detail over the past two decades. Parallel mechanisms are essentially the same design layout, a base, multiple legs/limbs, and a moving platform with a single end-effector to allow the mechanism to complete its desired function. Recently, several research groups have begun looking into multiple-platform parallel mechanisms and/or multiple end-effectors for parallel mechanisms. The reason for the research in this new form of parallel mechanism stems from multiple sources, such as applications that would require multiple handling points being accessed simultaneously, a more controlled gripper motion by having the jaws of the gripper being attached at different platforms, or to increasing the workload of the mechanism. The aim of the thesis is to modify the design process of parallel mechanisms so that it will support the development of a new parallel mechanism with multiple platforms capable of moving relative to each other in at least 1-DOF and to analyse the improvements made on the traditional single platform mechanism through a comparison of the power requirements for each mechanism. Throughout the thesis, a modified approach to the type synthesis of a parallel mechanism with multiple moving platforms is proposed and used to create several case study mechanisms. Additionally, this thesis presents a new series of methods for determining the workspace, inverse kinematic and dynamic models, and the integration of these systems into the design of a control system. All methods are vetted through case studies where they are judged based on the results gained from existing published data. Lastly, the concepts in this thesis are combined to produce a physical multi-platform parallel mechanism case study with the process being developed at each stage. Finally, a series of proposed topics of future research are listed along with the limitations and contributions of this work

NASA space station automation: AI-based technology review

Research and Development projects in automation for the Space Station are discussed. Artificial Intelligence (AI) based automation technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics. AI technology will also be developed for the servicing of satellites at the Space Station, system monitoring and diagnosis, space manufacturing, and the assembly of large space structures

Development of Two Cooperative Stewart Platforms for Machining

Ph.DDOCTOR OF PHILOSOPH

Synthesis of Planar Parallel Mechanism

Parallel mechanisms are found as positioning platforms in several applications in robotics and production engineering. Today there are various types of these mechanisms based on the strcture, type of joints and degree of freedom. An important and basic planar mechanism providing three degree of freedom at the end-effector (movable platform) is a 3-RPR linkage. Here the underscore below P indicates the presence of actuated prismatic joints and 3 indicates the number of legs used to carry the mobile platform. A lot of work has been done on this mechanism since 1988. In the present work, the kinematics of 3-RPR linkage is specifically studied to understand the synthesis procedure. The forward kinematics in parallel mechanisms is a multi-solution problem and involves cumbersome calculations compared to inverse kinematics. In inverse kinematics, we design the actuator input kinematic parameters for a known table center coordinates. In other words it is a transformation of platform pose vector to the actuator degrees of freedom. In 3-RPR mechanism considered in present task, the actuators are sliders and hence the slider displacements reflect the input degrees of freedom. On the other hand, for a known posture (available slider displacement status), the table center coordinates are predicted in forward kinematics. In present work, forward kinematics solutions are obtained by defining error function and optimizing it using genetic algorithms programs. Also, the workspace and Jacobian matrices are computed at corresponding solution and singularity analysis is briefly highlighted