LOAD CAPACITY OF HELICOIL® INSERTS IN ABS M30 MATERIAL USED FOR ADDITIVE MANUFACTURING

This paper deals with experimental investigations and numerical simulations of HELICOIL® inserts in ABS-M30 plastic. The aim is to explore the possibilities of modelling HELICOIL® inserts using Finite Element Method (FEM) and thus predict the load-bearing capacity of these inserts. The motivation was based on a previously published article that dealt with the topological design of the robot manipulator arm shape. During the mechanical tests, the structure of the arm did not collapse, but the HELICOIL® inserts were torn out. To determine the load-bearing capacity of HELICOIL® inserts, the necessary experimental tests were designed and carried out. FEM calculations of the inserts were adjusted to the obtained data. The results from the FEM were verified in an experimental validation test.

A numerical algorithm to find optimum parameters of a flexible-link manipulator arm for performing payload launching

PurposeThe aim of the current study is proposing a novel framework to attain the optimum value of a flexible arm manipulator parameters for payload launching missions.Design/methodology/approachThe proposed scheme is based on optimal control approach and combines direct and indirect search methods while considering the actuator capacity.FindingsThree nonlinear parameter-optimization problems will be solved to illustrate how the proposed algorithm can be exploited. Employing variational based nonlinear optimal control within the suggested framework, the answer of these problems is highly intertwined to the solution of a set of differential equations with split boundary values. To solve the obtained boundary value problem (BVP), the related solver of MATLAB® software, bvp6c, will be employed. The achieved simulation results support the worth of the developed procedure.Originality/valueFor the first time, the optimal parameters of a flexible link robot for object launching are found in the current research. In addition, the actuator saturation limits are considered which enhances the applicability of the suggested method in the real world applications.

Optimization of a Truss Structure Used to Design of the Manipulator Arm from a Set of Components

The design of a manipulator arm, which is built from a construction kit, is presented in this article. The procedure is based on the results of the discrete optimization of a truss structure and its application to a simple component system (assuming a predefined shape and material of components). A genetic algorithm is used to optimize the truss structure, and the results of the solution are verified on a simple task used in literature (the code was written in the Python language). The construction kit was inspired by Merkur®, and the article proposes several components with different shapes and materials. The construction kit and the optimization of the truss structure were used to design the manipulator arm. The truss topology has been predefined with respect to the construction set. The finite element method (software ANSYS®) was used to analyze the components (shell elements) and truss structures (linear analysis, buckling analysis, etc.). To validate the presented approach, the arm designed by topological optimization was used. The comparison shows that the use of components may be an alternative to topology optimization and additive manufacturing. The next step will be the modification of the presented method in order to minimize the differences between the simplified task used for optimization (truss structure-rod element) and the simulation composed of components (components assembly-shell element).

CALCULATION OF MANIPULATOR EXPERIMENTAL MODEL FOR STUDYING THE METHODS OF LEARNING (WITH REINFORCEMENT)

Reinforcement learning is a type of machine learning algorithm. These algorithms interact with the model of the environment in which the robotic system is supposed to be used, and make it possible to obtain relatively simple approximations of effective sets of system actions to achieve the set goal. The use of reinforcement learning will allow training the model on server hardware, and in the final system use already trained neural networks, the complexity of calculating the response of which directly depends on their topology. In the presented work, a statistical calculation of a prototype of a robotic manipulator for bench research of reinforcement learning systems has been carried out. The choice of design features and materials has been substantiated; the main units and design features have been considered. The studies were carried out in the SolidWorks Simulation software. A prototype of a robotic manipulator with a sufficiently high safety margin was obtained. It is concluded that the main stress concentrator is the junction of the eyelet and the platform, however, the maximum stress value was 38.804 kgf/sm2, which is insignificant. In this case, the maximum resulting movement will be concentrated in the upper part of the eyelet, and will shift depending on the position of the manipulator arm. The maximum recorded displacement is 0.073 mm, which is negligible

Analysis and perspectives of robotic systems for psychological support of spacecraft crews

С развитием космических программ возникает необходимость применять различные виды психологической поддержки космонавтов с целью сохранения их социальной активности и высокой работоспособности. В статье анализируются возможности использования для этих целей « социальных » роботов, проводится краткий обзор существующих моделей, и формулируются требования для компактных автономных конструкций такого рода. В качестве прототипа предлагается использовать устройства, снабжённые рукой-манипулятором и захватом, что позволяет им совершать простейшие механические действия, а также перемещаться по станции. Избыточные степени свободы позволяют роботу совершать широкий спектр движений, которые напоминают поведение домашних животных, а также могут интерпретироваться в терминах человеческих эмоций. В статье делается вывод об особой роли специализированного программного обеспечения на С-подобном языке, с помощью которого можно реализовать все поведенческие особенности социального робота. With the development of space programs, it becomes necessary to apply various types of psychological support to cosmonauts in order to maintain their social activity and high performance. The article analyzes the possibilities of using «social» robots for these purposes, provides a brief review of existing models and formulates requirements for compact autonomous structures of this kind. As a prototype, it is proposed to use devices equipped with a manipulator arm and a gripper, which allows them to perform the simplest mechanical actions, as well as move around the station. Excessive degrees of freedom allow the robot to perform a wide range of movements that resemble pet behavior and can also be interpreted in terms of human emotions. The article concludes about the special role of specialized software in the C-like language, with which it is possible to implement all the behavioral features of a social robot.

Additive manufacturing of a continuum topology-optimized palletizing manipulator arm

In this article, the lightweight design of a palletizing manipulator arm structure is carried out. The optimization target is designed in 3D with Solid Works. To determine the optimization area and the secondary reconstruction model after the structure is optimized, the reliability and cost of the design structure are also considered. The meta-software performs mechanical performance simulation experiments under the corresponding working conditions for the lightweight structural design of the target structure via the topology optimization methods. Finally, with additive manufacturing technology, the design and printing of the filled skeletal Voronoi structure and the nested-external-removal Voronoi structure of the palletizing manipulator arm are performed.