Kinematics of Serial Manipulators

This book chapter deals with kinematic modeling of serial robot manipulators (open-chain multibody systems) with focus on forward as well as inverse kinematic model. At first, the chapter describes basic important definitions in the area of manipulators kinematics. Subsequently, the rigid body motion is presented and basic mathematical apparatus is introduced. Based on rigid body conventions, the forward kinematic model is established including one of the most used approaches in robot kinematics, namely the Denavit-Hartenberg convention. The last section of the chapter analyzes inverse kinematic modeling including analytical, geometrical, and numerical solutions. The chapter offers several examples of serial manipulators with its mathematical solution

Substantiation of design parameters of bernoulli grippers with automated control of the sizes of objects of manipulation

The advantages of using jet gripping devices with integrated function of size control of objects of manipulation in robotic systems are substantiated. Rational designs of gripping devices are proposed, which allow to measure the diameter of the object held by them, their design parameters are substantiated. The interaction of air flows flowing from the annular nozzle and measuring ejector nozzles in the gap between the outer surface of the jet gripper and the inner surface of the object of manipulation is carried out. Reynolds-averaged Navier-Stokes equations of viscous gas dynamics, SST-model of turbulence and γ-model of laminar-turbulent transition were used for this purpose. As a result of numerical simulation in the Ansys-CFX software environment, the influence of the spatial location of the measuring nozzles on the load capacity of the jet gripper, the range and accuracy of measuring the diameters of manipulation objects was determined

Analysis of power characteristics of a bernoulli gripping device for manipulation of textile materials

Обґрунтовано актуальність застосування струминних захоплювачів при роботизації швейних виробництв. Проаналізовано параметри потоку повітря у радіальному проміжку між взаємодіючими поверхнями струминного захоплювального пристрою та деталі з текстильного матеріалу. Представлено методику розрахунку сили утримування струминним захоплювачем деталі з текстильного матеріалу.Actuality of the use of Bernoulli grippers with robotics garment industries. The parameters of the air flow in the radial gap between the interacting surfaces of the Bernoulli gripper device and the details of the textile material have been analyzed. The method of calculating the lifting force an Bernoulli gripper of a textile material component is presented

Classification of rolled metal defects using residual neural networks

The authors investigated deep residual neural networks, which are used to detect and classify defects found on the rolled metal surface. Based on the neural network with ResNet152 architecture, a classifier for recognizing defects of three classes was built. The proposed technique allows recognizing and classifying surface damage with high accuracy in real-time based on its image. The average binary accuracy of the classification made based on the test data is 97.3%. Neuron activation fields were studied in the convolutional layers of the model. The results obtained show that areas, which correspond to those with damage in the image, are activated. False-positive and false-negative cases of classifier application are investigated. Errors were found to occur most frequently in ambiguous situations when surface artefacts of different types are similar

Chimney sweeping robot based on a pneumatic actuator

The need of improving the quality of professions led to the idea of simplification of processes during chimney sweeping. These processes have been essentially the same for tens of years. The goal of this paper is to bring an automation element into the chimney sweeping process, making the job easier for the chimney sweeper. In this paper, an essentially in-pipe robot is presented, which uses brushes to move while simultaneously cleaning the chimney or pipeline. The problem of the robot motion was reduced using an in-pipe robot due to the environments and obstacles that the robot has to face. An approach of using a pneumatic actuator for motion is presented along with the mechanical design. The next part of this paper is focused on the mathematical model of the robot motion, as well as its simulation and testing in the experimental pipeline. The simulations were compared with the experimental measurements and a few analyses were conducted describing the simulation model and its differences with the real robot, as well as considering certain parameters and their impact on the performance of the robot. The results are discussed at the end of the paper.Web of Science1111art. no. 487

Upgrade of biaxial mechatronic testing machine for cruciform specimens and verification by FEM analysis

This article deals with the modernization of an existing loading system for the analysis of elastic-plastic properties of sheet metals in plane stress. The identification of the beginning of plastic deformation of sheet metal in plane strain is important in the cold pressing of sheet metal and in the assessment of the load capacity of thin-walled structures in the automotive and aerospace industry. The design of the control structure of the hydraulic part of the loading system for cross testing was carried out to automatize the whole process of experimental evaluation. For this purpose, proportional pressure-reducing valves together with control electronics were designed. Thus, the loading system is a control system for which a control algorithm has been designed and implemented on a PC. A computer simulation was performed to verify the functionality of the load system. An FEM simulation was performed to verify the correctness of the proposed numerical models and to confirm the experimental results. A numerical nonlinear model of the selected material was applied for the specification of plastic deformations. From the results, it is possible to state the appropriateness of the used models as well as the appropriateness of using modernized equipment for subsequent analysis of the plastic deformation of cruciform specimens.Web of Science1010art. no. 91

Biped robot with unconventional kinematics

The article deals with the design of a robot with an unconventional kinematic structure, which is able to vertically stabilize the position of the robot base for the placement of sensors and handling superstructures. The robot concept was designed to have as few actuators as possible. The robot's kinematics was solved for the purpose of simulating the robot's movement and implementation into the robot's control system.Web of Science20225824581

GrassPlot v. 2.00 – first update on the database of multi-scale plant diversity in Palaearctic grasslands

Abstract: GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). Following a previous Long Database Report (Dengler et al. 2018, Phyto- coenologia 48, 331–347), we provide here the first update on content and functionality of GrassPlot. The current version (GrassPlot v. 2.00) contains a total of 190,673 plots of different grain sizes across 28,171 independent plots, with 4,654 nested-plot series including at least four grain sizes. The database has improved its content as well as its functionality, including addition and harmonization of header data (land use, information on nestedness, structure and ecology) and preparation of species composition data. Currently, GrassPlot data are intensively used for broad-scale analyses of different aspects of alpha and beta diversity in grassland ecosystems

GrassPlot - a database of multi-scale plant diversity in Palaearctic grasslands

GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (releves) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001;... 1,000 m(2)) and on nested-plot series with at least four different grain sizes. The usage of GrassPlot is regulated through Bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata. However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetationplot databases, such as the European Vegetation Archive (EVA) and the global database " sPlot". Its main aim is to facilitate studies on the scale-and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Governing Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board