ORGANIZATION PRINCIPLES OF THE PARALLEL KINEMATIC STRUCTURE MACHINES AND MECHANISMS DRIVE SYSTEMS CYBER-PHYSICAL INTERACTION

2021 ◽  
pp. 37-42
Author(s):  
Tatiana Kruglova
Keyword(s):  
Physical Interaction ◽  
Kinematic Structure ◽  
Parallel Kinematic ◽  
Drive Systems

scholarly journals Modal Kinematic Analysis of a Parallel Kinematic Robot with Low-Stiffness Transmissions

Robotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 132
Author(s):  
Paolo Righettini ◽  
Roberto Strada ◽  
Filippo Cortinovis
Keyword(s):  
High Speed ◽  
Parallel Robots ◽  
Maximum Speed ◽  
Kinematic Structure ◽  
End Effector ◽  
New Approach ◽  
Working Space ◽  
Modes Of Vibration ◽  
Parallel Kinematic ◽  
Actuated Joints

Several industrial robotic applications that require high speed or high stiffness-to-inertia ratios use parallel kinematic robots. In the cases where the critical point of the application is the speed, the compliance of the main mechanical transmissions placed between the actuators and the parallel kinematic structure can be significantly higher than that of the parallel kinematic structure itself. This paper deals with this kind of system, where the overall performance depends on the maximum speed and on the dynamic behavior. Our research proposes a new approach for the investigation of the modes of vibration of the end-effector placed on the robot structure for a system where the transmission’s compliance is not negligible in relation to the flexibility of the parallel kinematic structure. The approach considers the kinematic and dynamic coupling due to the parallel kinematic structure, the system’s mass distribution and the transmission’s stiffness. In the literature, several papers deal with the dynamic vibration analysis of parallel robots. Some of these also consider the transmissions between the motors and the actuated joints. However, these works mainly deal with the modal analysis of the robot’s mechanical structure or the displacement analysis of the transmission’s effects on the positioning error of the end-effector. The discussion of the proposed approach takes into consideration a linear delta robot. The results show that the system’s natural frequencies and the directions of the end-effector’s modal displacements strongly depend on its position in the working space.

scholarly journals Modelling and Simulation of Machine Tool Prototype with 6DOF Parallel Mechanism in Matlab / Simulink

2019 ◽  
Vol 254 ◽  
pp. 03002 ◽  
Author(s):  
Vladimír Bulej ◽  
Juraj Uríček ◽  
Manfred Eberth ◽  
Ivan Kuric ◽  
Ján Stanček
Keyword(s):  
Machine Tool ◽  
Simulation Model ◽  
Mechanical System ◽  
Parallel Mechanism ◽  
Control Algorithms ◽  
Kinematic Structure ◽  
Matlab Simulink ◽  
Parallel Kinematic ◽  
Functional Blocks ◽  
Functional Prototype

The article deals with the preparation of simulation model of mechanism with parallel kinematic structure called hexapod as an electro-mechanical system in software MATLAB/Simulink. The simulation model is composed from functional blocks represented each part of mechanism’s kinematic structure with certain properties. The results should be used for further simulation of its behaviour as well as for generating of control algorithms for real functional prototype.

Parallel Mechanism for Precision Sun Tracking

2010 ◽  
Author(s):  
Stefano Mauro ◽  
Cristina Scarzella
Keyword(s):  
Parallel Mechanism ◽  
Inverse Kinematic ◽  
Kinematic Structure ◽  
Parallel Kinematic Machine ◽  
Photovoltaic Modules ◽  
Solar Tracking ◽  
Parallel Kinematic

The paper describes a 2-DOF parallel kinematic machine designed to achieve precise solar tracking. The mechanism has been developed keeping in mind that solar concentration technology requires a precise alignment of photovoltaic modules and sun radiation, with error allowance much lower than those ensured by traditional sun trackers. The paper describes the kinematic structure and discusses its forward and inverse kinematic, providing the tools to design a system that satisfies the requirements for dexterity and workspace.

Parallel Mechanism and its Application in Design of Machine Tool with Numerical Control

2013 ◽  
Vol 282 ◽  
pp. 74-79 ◽  
Author(s):  
Viera Poppeova ◽  
Vladimir Bulej ◽  
Robert Zahoranský ◽  
Juraj Uríček
Keyword(s):  
Machine Tool ◽  
Parallel Mechanism ◽  
Numerical Control ◽  
Kinematic Structure ◽  
Final Solution ◽  
Risk Of Injury ◽  
Real Risk ◽  
Parallel Kinematic ◽  
Automatic Tool ◽  
And Robotics

This paper describes the design of machine tool based on the mechanism with parallel kinematic structure (PKS) called hexapod. The advantages of mechanisms with PKS predetermine them to the field of machining and robotics. Machine tool is designed like fully automated device contains system for automatic tool and part changing too. There was necessary to solve also a question of operation safety according to the real risk of injury. Some information about the design process, main requirements, the problems and the final solution can be found in this paper.

scholarly journals Method for assessing the current and additional load on the parallel kinematic structure mechanisms electric drive system

2021 ◽  
Vol 21 (3) ◽  
pp. 268-274
Author(s):  
T. N. Kruglova
Keyword(s):  
Electric Drive ◽  
Electric Motor ◽  
Drive System ◽  
Kinematic Structure ◽  
Wavelet Coefficients ◽  
Current Load ◽  
Premature Failure ◽  
Additional Load ◽  
Electric Drive System ◽  
Parallel Kinematic

Introduction. The problem of the load on an electric drive system in a parallel kinematic structure is considered. The task of developing a fault-tolerant system that provides performing a given process in case of a failure of one or more drives is described. The work objective is to create a method for estimating the current and additional load on each drive of the mechanism of a parallel kinematic structure. The solution enables to correct the operating mode when performing a given process without compromising serviceable drives.Materials and Methods. Previously, a diagnostic method was developed. It is based on the calculation and analysis of the coefficients of straight lines that approximate the envelopes of the values of the wavelet transform coefficients of electric motor current signals, taking into account the characteristic scales. This makes it possible to determine the current technical condition of the electric motor and find malfunctions. The logical continuation of this approach is the proposed method for assessing the current and additional load. It provides finding the current load on the drive based on the coefficients of the lines approximating the envelopes of the wavelet coefficients of the current signal. To calculate the additional load, the number and location of faulty drives are taken into account.Results. For each scale of the wavelet coefficients, the relative coefficients and the current load on each drive are determined. The possibility of redistributing the load to two adjacent jacks was checked; the behavior of the system in this case was investigated. The load moved by the faulty jack is redistributed to two adjacent jacks in equal shares — 14.76 % each. The total load on the drives is 44.28 %, which is safe for the servo. The load on the drive of the fourth jack does not change (29.52 %). The drives have a sufficient safety margin. It is established that all three operating modes are acceptable for the studied servo drive, and they do not cause dynamic overloads and premature failure.Discussion and Conclusions. The experimental studies on the method of assessing the current and additional load have shown its adequacy and high efficiency. It was found that when the drives were disconnected from one of the racks of the mechanism, the system performed a load redistribution on the drives. Thus, it was possible to avoid their dynamic overloads and premature failure. This means that the solution is able to ensure the reliable functioning of the complex at the time of renovation work.

scholarly journals Positioning uncertainty of the Tricept type parallel kinematic structure

ACTA IMEKO ◽  
2015 ◽  
Vol 4 (4) ◽  
pp. 9
Author(s):  
Eva Kureková ◽  
Milada Omachelová ◽  
Martin Halaj ◽  
Ilja Martišovitš
Keyword(s):  
Mathematical Model ◽  
Machine Design ◽  
Kinematic Structure ◽  
Positioning Accuracy ◽  
Parallel Structures ◽  
Final Design ◽  
Geometrical Imperfections ◽  
Parallel Kinematic ◽  
The Mathematical Model

The paper discusses theoretical aspects that arised during determination of theoretical positioning accuracy of parallel kinematic structures (PKS) with special regard to the Tricept type PKS. Apart from the conventional serial structures that employ translate or rotational movement (or their combination) of individual driving axes, parallel structures comprise a set of telescopic driving rods that are joined together via solid platform. Due to this fact, the mathematical model describing relationship between the driving actions of telescopic rods and resulting coordinates of the desired effector's endpoint is rather complex. To determine the theoretically achievable positioning accuracy of the endpoint, authors investigated theoretical influence of geometrical imperfections of the machine design and employed the law of uncertainties propagation. Their aim was to investigate theoretically achievable positioning accuracy of the machine prior to the final design solutions thus helping the designer to optimize the machine's design.

Whole Body Control of a Dual-Arm Mobile Robot Using a Virtual Kinematic Chain

2016 ◽  
Vol 13 (01) ◽  
pp. 1550047 ◽  
Author(s):  
Yuquan Wang ◽  
Christian Smith ◽  
Yiannis Karayiannidis ◽  
Petter Ögren
Keyword(s):  
Degrees Of Freedom ◽  
Kinematic Chain ◽  
Inverse Kinematic ◽  
Whole Body ◽  
Kinematic Structure ◽  
The Common ◽  
Parallel Kinematic ◽  
Programming Solution ◽  
Dual Arm ◽  
Mobile Base

Dual-arm manipulators have more advanced manipulation abilities compared to single-arm manipulators and manipulators mounted on a mobile base have additional mobility and a larger workspace. Combining these advantages, mobile dual-arm robots are expected to perform a variety of tasks in the future. Kinematically, the configuration of two arms that branches from the mobile base results in a serial-to-parallel kinematic structure. In order to respond to external disturbances, this serial-to-parallel kinematic structure makes inverse kinematic computations non-trivial, as the motion of the base has to take the needs of both arms into account. Instead of using the dual-arm kinematics directly, we propose to use a virtual kinematic chain (VKC) to specify the common motion of the two arms. We formulate a constraint-based programming solution which consists of two parts. In the first part, we use an extended serial kinematic chain including the mobile base and the VKC to formulate constraints that realize the desired orientation and translation expressed in the world frame. In the second part, we use the resolved VKC motion to constrain the common motion of the two arms. In order to explore the redundancy of the two arms in an optimization framework, we also provide a VKC-oriented manipulability measure as well as its closed-form gradient. We verify the proposed approach with simulations and experiments that are performed on a PR2 robot, which has two 7 degrees of freedom (DoF) arms and a 3 DoF mobile base.

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