Mechatronic design of a parallel manipulator for milling (original) (raw)

A new 3DOF parallel manipulator

2004

The paper presents a novel, versatile 3-RRPRR (Revolute-Revolute-Prismatic-Revolute-Revolute joints), fully-parallel manipulator with three translational degrees of freedom for pick-and-place and machining applications, characterising in comparatively high payload capacity, large workspace and high attainable accelerations. The construction of the manipulator is shown, its kinematics and dynamics is analysed and modelled. A trajectory generator and a controller are proposed, simulated and experimentally investigated. Finally, the conclusions and future works are presented.

A parallel robot with three translational degrees of freedom for machining operations

2017

This paper proposes a new machine tool structure design for machining based on a Delta Robot architecture as object of study, known as Tsai's Manipulator, patented by Tsai in 1997. The new architecture employs only rotary joints instead of spherical ones as it is usual for Delta Robots. The rotary joints allow its mount under pretension to eliminate clearances or backlash, avoiding the use of expensive spherical joints. All the other mechanical parts are standard components, which makes the solution attractive in terms of cost. A simplified inverse kinematic solution over the one proposed by Tsai is presented, based on a practical approach. The simplified solution reduces the number of steps to solve the inverse kinematics without any loss of performance. In addition, a solution to deal with the coupled axis without parasitic motion is presented. To increase the accuracy and the stiffness of the robot, a special attention was given to the rotary joints using preload rotational ball bearing joints. The structure parts were manufactured mostly by laser cutting with almost no complementary machining processes. In order to evaluate the proposed solutions, a prototype was built and a dedicated control software was developed for this particular robot. Workpieces were milled with the robot to demonstrate its capability and the advantages regarding the proposed machine architecture.

IJERT-Design and Development of 3-DOF RPR Planar Parallel Robot

International Journal of Engineering Research and Technology (IJERT), 2014

https://www.ijert.org/design-and-development-of-3-dof-rpr-planar-parallel-robot https://www.ijert.org/research/design-and-development-of-3-dof-rpr-planar-parallel-robot-IJERTV3IS030308.pdf Use of parallel mechanism as a robot manipulator is an emerging technology in the field of robotics. This paper represents the kinematic modeling and synthesis of three degree of freedom planer parallel mechanism. Use of a parallel mechanism as a robot manipulator has its own potential merits like, high structural rigidity, good dynamic performance, high load carrying capacity and precision positioning. Forward kinematic analysis is essential for evolution of the work volume of the robot and design of the feedback control system design. While the inverse kinematic analysis is essential for synthesis of robot manipulator and design of continuous control system. This paper also includes the development of the working model of the 3-DOF parallel planer robot. Because of precise positioning capability this manipulator can be used for generation of the planer profiles, welding and cutting on planer geometry.

A Novel Parallel Manipulator Architecture for Manufacturing Applications

Multibody System Dynamics, 2003

This paper proposes a new type of a six-degree-of-freedom parallelmanipulator with six prismatic legs for manufacturing applications. Eachleg is connected to a base by universal and prismatic joints, and to amoving platform by spherical joints. Based on the complete kinematicsmodel developed in this paper, analytical expressions are derived forthe displacement, velocity and accelerations. The dynamic equations ofthe manipulator are obtained

Performance Evaluation of Parallel Manipulators for Milling Application

Global Product Development, 2011

This paper focuses on the performance evaluation of the parallel manipulators for milling of composite materials. For this application the most significant performance measurements, which denote the ability of the manipulator for the machining are defined. In this case, optimal synthesis task is solved as a multicriterion optimization problem with respect to the geometric, kinematic, kinetostatic, elastostostatic, dynamic properties. It is shown that stiffness is an important performance factor. Previous models operate with links approximation and calculate stiffness matrix in the neighborhood of initial point. This is a reason why a new way for stiffness matrix calculation is proposed. This method is illustrated in a concrete industrial problem.

Kinematic Analysis of A 3-DOF Parallel Mechanism for Milling Applications

The Open Mechanical Engineering Journal, 2010

Parallel mechanisms have been studied during the last two decades, due to the fact that they present some potential advantages in a comparison with serial structures. This work presents the kinematic analysis of a novel 3-dof asymmetric parallel mechanism, purposely conceived for milling applications. In a comparison with the previous proposed concepts, this type of kinematic structure shows some advantages. The architecture is simpler and lighter than Tricept because it has no central passive limb. In addition, only the central active limb needs to satisfy the parallelism and orthogonality conditions. Furthermore, one degree of freedom, associated to the third actuator, is decoupled from the other two. Important issues, related to this type of kinematic structure, such as position and velocity analysis, singularity occurrence prediction and workspace evaluation, are discussed in detail.

296 Novel Design of a 4 DOF Parallel Robot

regional-robotics.org

This work illustrates the novel design of a unique 4 degree-of -freedom parallel robot with 3 DOF in translation and one DOF in rotation. The forward and inverse kinematics will be detailed including the analysis of the singularities of the mechanism. The extensive simulation of the system is proposed. The design methodology shows the advantage over the other conventional method in less complexity of the direct kinematics solutions which can be extended to 5 or 6 DOF parallel robot. The purpose configuration can be applied to the rapid prototype application and also the 5-axis milling machine for advance manufacturing application.

Designing a parallel-kinematic high-speed machine tool

Parallel mechanisms have many features such as high payload, high speed, high acceleration, high rigidity (stiffness), and low inertial and non-accumulating error, these advantages makes it excellent for machine tool applications. In the present study, the analysis of a category of parallel manipulators for the purpose of designing machine tools is developed. First, the solutions of the inverse and forward kinematic problems of the present manipulator are developed. These solutions are then used to determine reachable workspace of the present manipulator at different orientations of the moving platform. It is found that the maximum reachable workspace occurs when the orientation of the moving platform is The Jacobian analysis of the proposed manipulator is introduced and the singular configurations are determined. Second, the dynamic model of the proposed manipulator is developed and is used to determine the actuation forces for different trajectories. Finally, simulation models built using ADAMS software are used to validate the developed kinematic and dynamic models. The simulation shows a good agreement between the results obtained using the developed models and those obtained using ADAMS models.

Kinematic analysis and design of a 3-DOF translational parallel robot

International Journal of Automation and Computing, 2017

Parallel mechanisms are widely used in various fields of engineering and industrial applications such as machine tools, flight simulators, earthquake simulators, medical equipment, etc. Parallel mechanisms are restricted to some limitations such as irregular workspace, existence of singular points and complexity of control systems which should be studied and analyzed for effective and efficient use. In this research, a new machine tool with parallel mechanism which has three translational degrees of freedom is studied and the workspace and singular points are determined by deriving analytical equations and then utilizing of Matlab software. To do so, forward and inverse kinematics of the mechanism are obtained and workspace and singular points are calculated using a search algorithm. Afterward, in order to validate the results, the proposed mechanism is simulated in automatic dynamics analysis of mechanical systems (ADAMS) software. Moreover, in order to investigate the quality of robot performance and dexterity of the mechanism in its workspace, global dexterity index (GDI) of the robot is calculated using Jacobean matrix at different positions of the mobile platform.

Didactic Prototype of a Machine Tool Based on a Parallel Kinematic Mechanism

In the past recent years Parallel Kinematic Mechanisms (PKM) have attracted a lot of attention from academic and industrial communities due to their potential applications not only as robot manipulators but also as machine tools. Traditionally, these systems are employed as flight simulators for pilot training or even people entertaining. From the analysis of their typical topologies, it can be observed that they are composed by two or more closed kinematic chain mechanisms. In general, they demonstrate a higher performance than serial kinematic mechanisms, once the last ones present deficiencies related to structural stiffness, load capacity and positioning accuracy. On the other hand, parallel kinematic mechanisms are much more rigid, accurate and have higher load capacity and, therefore, can be lighter. Besides, when these mechanisms are used as machine tools, they are able to produce workpieces with very complex geometries, giving shapes and surfaces which would be difficult to obtain from conventional or even NC machine tools. This article deals with a type of parallel kinematic mechanism with four degrees of mobility that allows positioning and orientation of the platform (table) that supports a piece to be machined. This article also presents the mechanism mathematical model, describes the prototype built, shows technical specifications of its subsystems and comments its future applications.