Applied Mechanics and Materials Vol. 613

Abstract: A cognitive approach conceptualizes the goods producing enterprise and its production factors (such as divisions, units, sections or resources like machines or robots) as well as the enterprise’s products (such as valves) as cognitive models. These models are then put into shape with the help of cognitive computing techniques.

Abstract: The paper deals with problems of designing and evaluation of compliant mechanisms for small and micro robotic devices. These kinematic mechanisms are usually made from a piece of elastic material in case of positioning systems, or, create the flexural body for multi-component sensing devices. The compliance characteristics mechanical segments: joints, arms, are discussed and the procedure for evaluation / comparing characteristics of particular segments, as well as whole elastic structures is proposed. It is briefly discussed that mechanisms for this kind of devices should integrate functional features of positioning and sensing systems. The concept of the x – y micro positioning mechanisms with two-component force sensing capability is presented as an illustrative example.

Abstract: The purpose of this paper is to elaborate not on the bionic pattern of walking robot. Our own simple idea of 4 degree of freedom (DOF) walking robot with the ability to walk on flat surfaces, rotate and climbing upstairs was made using vertical moved legs with rotary foot and additional controlled mass. In this paper, based on former idea, prototype model for only flat surface walking task 3 DOF were presented. Parts of the robot are moving thanks to servo motors. The paper contains kinematics and centre of gravity analysis, presentation of robot and its control system made using Pololu controller. Conducted experiments confirmed presented idea.

Abstract: This paper is dedicated to the development and implementation of a robotic vehicle in the intermediate category suitable for deployment in rough terrain for rescue and recovery purposes [1]. The requirements on the part of potential users have been clarified with the relevant departments such as the police, civil protection, Fire Corps, and army EOD specialists. On basis of analysis, categories of requirements were defined in the field of terrain and environment characteristics. The result of the development is a compact vehicle equipped with 6-legs for walking in combination with wheels at the end of the each leg for fast driving. In the front section there is free space for a special-purpose superstructure, in the standard package it consists of a handling arm with 6 degrees of freedom with a deadweight capacity of 200kg. All actuators, including the wheel drive, are hydraulic, the hydraulic pump and electric generator are driven by built-in internal combustion engine.

Abstract: The paper describes control structure for driving system of a leg in six-legged robot vehicle. It can walk using locked wheels or it can roll on unlocked wheels. The leg joints are driven by hydraulic actuating units. Two different control structures are analyzed – control of a hydraulic cylinder through a mechanical gear and a structure for control of two hydraulic cylinders through a double eccentric gear mechanism. For control of the actuating units a conventional cascade structure with PI controllers completed by pre-compensation of controlled and observed variables is used. The performance of the structure has been proved on experimental stand and the experimental results are reported.

Abstract: Activities in the field of increasing the productivity of the production lines for welding thick metal sheets are focused in two directions. On the one hand, new technologies are being developed for welding, deeper weld penetration and faster welding process. On the other hand are focused on automation of these operations, which have the effect of reducing cost and increasing efficiency. Improved are also the working conditions of people employed in the welding processes. In both these directions the hybrid welding Plasma-GMAW could fulfill all requirements as a new technology. The article gives the concept model of the complete robotized welding cell, in which this method will be implemented and tested.

Abstract: Coordinated motion of two robots in Cartesian space is considered in the paper. Coordinated trajectory is generated as the sum of two motions: programmed and corrective. The corrective motion aims at limitation of the interaction force between robots. For calculation of the corrective motion speed the idea of mechanical impedance is used. As a measure of force interactions between robots change of distance between robots TCPs is used. Simulation experiments carried out for one dimensional case show that application of impedance based correctors results in the linear growth of change of distance between robots TCPs for constant difference between robots programmed speeds. Thus a modification of impedance based correctors is proposed. The modification consists in introduction of an integrating element in series with impedance corrector. Simulation tests for the modified correctors provide improved results – magnitude of change of distance is decreased. Linear increase of change of distance for impedance corrector is changed into a constant non zero value, whereas constant non zero value is changed into zero value. Simulation results for two dimensional case of coordinated motion are also presented.

Abstract: The paper is focused on the determination of the number of robots for multi robotic cells that can be part of the line, respectively as an individual, for example sub-assemblies welding of car bodies. This paper describes general process steps of the methodology of design of multi robotic systems with a more detailed description of the determination of number of robots in the workplace. Some methodological steps are illustrated by specific examples.

Abstract: This article deals with simple image processing algorithms which are used for navigation of the robot in unknown environment. In the beginning of the article image processing procedures used in these algorithms are defined. The transformation of coordinate system of camera to robot’s coordinate system is introduced. The main body of the article consists of the definition of L-K optical flow method used in proposed visual odometry system. Article also contains the parameter settings of the used methods. Emphasis in these algorithms has been placed on simplicity and speed, so that they can be carried out in real-time. Algorithms have been verified on several scenarios.