Extraction and tracking of far background keypoints in dynamic monocular vision

Tracking of points lying in far background is of multiple importance in visual navigation, especially in tasks assuming fast camera motion dynamics. This paper describes an algorithm for efficient identification and tracking of such points using single monocular camera. The algorithm is based on a model of far background consisting of a set of tracked keypoints and associated membership degrees. The effectiveness of the proposed approach is demonstrated on open air video sequences. Some restrictions and further work necessary to operationalize the method are also considered.Praćenje tačaka udaljene pozadine je od višestrukog značaja u vizuelnoj navigaciji, posebno u zadacima koji pretpostavljaju brzu dinamiku kretanja kamere. U radu je opisan algoritam kojim se ostvaruje efikasna identifikacija i praæenje ovih tačaka korišćenjem monokularne vizije. Algoritam se zasniva na modelu udaljene pozadine koji se sastoji iz skupa kljuènih taèaka i asociranih stepena èlanstva. Efektivnost predloženog pristupa demonstirana je na video sekvencama dobijenim na otvorenom prostoru. Takođe su razmotrena neka ograničenja i dalji rad u cilju operacionalizacije metoda

Calibration of Kinect-type RGB-D sensors for robotic applications

The paper presents a calibration model suitable for software-based calibration of Kinect-type RGB-D sensors. Additionally, it describes a two-step calibration procedure assuming a use of only a simple checkerboard pattern. Finally, the paper presents a calibration case study, showing that the calibration may improve sensor accuracy 3 to 5 times, depending on the anticipated use of the sensor. The results obtained in this study using calibration models of different levels of complexity reveal that depth measurement correction is an important component of calibration as it may reduce by 50% the errors in sensor reading

A software system for teaching and commanding the industrial robots

Design features of a system for programming the industrial robots with dynamic control are described. When specifying the system, special attention was given to achieving hardware transportability, simplicity of communication between the user and the system, possibility of active user participation in generation of control algorithms, and possibility of implementing the software on a computer with relatively modest characteristics. The software is intended for implementation on a microprocessor-based system and should enable the user to control a robot via specialized programming language RL which incorporates structures for defining the positions and orientations of working points, motion specification, and synchronization of the robot with its environment. The paper contains descriptions of the RL language and of the system structure. The main characteristics and advantages of the system as well as questions concerning its realization on existing microprocessors are also discussed

Serbia Robotics Hall of Fame: the Impact of the Past

The paper presents a list of the most influential works of Serbian robotics. The list has been synthesized using document citation data from the Elsevier Scopus database and it shows that the impact of Serbia, compared to neighboring countries, has been highly disproportional and outperforming having in mind the Serbian economic and general scientific strength. However, the analysis also reveals that Serbia’s contribution has been significantly weakened during the last ten years and that Serbian robotics has been declining with respect to neighboring countries

Application of Kinect-type sensor in acquisition of hand joint trajectories

Rad prikazuje jedan pristup u merenju 3D pozicija karakterističnih zglobova ljudske šake korišćenjem senzora tipa Kinect, kao jeftine alternative skupim vizuelnim sistemima. Navedene su osnovne karakteristike ovog senzora i ukratko je opisan kalibracioni model i način integracije parametara kalibracije u proces izračunavanja 3D koordinata izabranih tačaka u prostoru. Analizirana je ostvarena tačnost u merenju 3D koordinata zglobova duž primera trajektorije hvatanja cilindra. Analiza je sprovedena posmatranjem devijacija izmerenih dužina pojedinih segmenata prstiju. Uočene su značajne razlike grešaka merenja u zavisnosti od pozicije zgloba\ud na šaci.This paper presents one approach for measurement of 3D positions of characteristic joints of human hand using a Kinect-type sensor as a low-cost alternative to expensive visual systems. Main properties of the sensor are indicated and a brief description of the calibration model and integration of calibration parameters in the process of calculating the 3D coordinates of selected points in space is given. Achieved accuracy in measurement of 3D coordinates of joints along sample cylinder grasping trajectory was analysed. The analysis was conducted by observing deviations in measured lengths of finger segments. Significant differences in measurement errors were found for different joints, depending on their position on the hand

An interactive program for generation and analysis of planning alternatives in complex water resource management systems

U radu je opisan računarski program namenjen za rešavanje problema višekriterijumskog odlučivanja u vodoprivrednom planiranju za slučaj kada su kriterijumske funkcije nelinearne i kada je domen dopustivih alternativa kompaktan. Generisanje neinferiornih alternativa ostvaruje se u programu korišćenjem metode e-ograničenja, dok se analiza mogućih alternativa i odredjivanje karakteristika preferentnog plana ostvaruje putem iterativne procedure koja se zasniva na metodi pomoćnih koeficijenata razmene vrednosti kriterijuma. Glavne prednosti rada s programom ogledaju se u mogućnosti interaktivnog rada, jednostavnosti korišćenja programa i velikoj brzini generisanja neinferiornih planskih alternativa.A computer program for solving multicriteria decision problems in water resources planning for the case of nonlinear criteria and compact domain of feasible alternatives is described. Generation of non-inferior alternatives is achieved using the method of e-constraints, while the analysis of feasible alternatives and determination of the preferred solution is performed via an iterative procedure based on the surrogate worth trade-off method. Main advantages of the program are its interactive capabi1ities, simplicity of use and high speed of generating the non-inferior planning alternatives

3D data acquisition and practical calibration of Microsoft Kinect camera

The paper presents introductory results on analyzing effectiveness of using Kinect camera in realization of robotic manipulation tasks. Two available communication interfaces, Kinect for Windows and OpenNI are considered and compared from the standpoint of 3D data acquisition. A practical method for calibration of Kinect camera is implemented. The method involves identification of internal parameters of Kinect RGB and depth camera and external parametars in the form of relative transformation between the cameras.U radu su prikazani uvodni rezultati analize efikasnosti upotrebe Kinect kamere u realizaciji robotskih zadataka koji se odnose na manipulaciju. Razmotreni su i uporeðeni softverski paketi Kinect for Windows i OpenNI sa stanovišta 3D akvizicije podataka. Implementirana je praktična metoda za kalibraciju Kinect kamere. Metoda uključuje identifikaciju unutrašnjih parametara RGB i dubinske kamere, kao i spoljašnjih parametara u vidu relativne transformacije između kamera

A programming language for commanding the industrial robots

Rad sadrži opis jezika RL namenjenog za programiranje neredundantnih robota sa do šest stepeni slobode. U definisanju strukture jezika posebna pažnja vodila se mogućnostima implementacije na miniračunarima srednje klase. RL je projektovan kao jezik visokog nivoa koji podrazumeva programiranje robota u spoljašnjim koordinatama i jednostavno izražavanje prostornih odnosa, definisanje radnih položaja korišćenjem samog robota i komunikaciju robota sa okolnom opremom. U jezik je uključen koncept radnih zadataka i privatnih varijabli, čime se programeru RL paketa pruža mogućnost zaštite sistema od neispravnog korišćenja.The paper contains a description of the language RL which is intended for programming of nonredundant robots with up to six degrees of freedom. When defining the language structure, a special attention was given to possibilities of its implementation on medium-class minicomputers. The RL is designed as a high level language supporting robot programming in external coordinates and simple expression of space relationships, definition of working positions using the robot itself, and communications between the robot and its surrounding equipment. A concept of operation tasks and private variables is included in the language, enabling the programmer to protect the system from improper use

Development of Modular Compliant Anthropomorphic Robot Hand

The chapter presents the development of a modular compliant robotic hand characterized by the anthropomorphic structure and functionality. The prototype is made based on experience in development of contemporary advanced artificial hands and taking into account the complementary aspects of human bio-mechanics. The robot hand developed in the Institute Mihailo Pupin is called “Pupin hand”. The Pupin hand is developed for research purposes as well as for implementation with service and medical robot devices as an advance robot end-effector. Mechanical design, system identification, modeling and simulation and acquisition of the biological skill of grasping adopted from humans are considered in the chapter. Mechanical structure of the tendon-driven, multi-finger, 23 degrees of freedom compliant robot hand is presented in the chapter. Model of the hand is represented by corresponding multi-body rigid system with the complementary structural elasticity inserted between the particular finger modules. Some characteristic simulation results are given in the chapter in order to validate the chosen design concept. For the purpose of motion capture of human grasping skill, an appropriate experimental setup is prepared. It includes an infrared Kinect camera that combines visual and depth information about objects from the environment. The aim of using the Kinect sensor is to acquire human grasping skill and to map this natural motion to the robotic device. The novelties of the robot hand prototyping beyond to the state-of-the-art are stressed out in the conclusion

A software system for teaching and commanding the industrial robots

Design features of a software system for programming industrial robots with dynamic control are described. The software is intended for implementation an a microprocessor-based system and should enable the user to control a robot via specialized programming language RL. The paper contains description of the RL language and description of the system structure. Main characteristics and advantages of the system as well as questions concerning its realization on existing microprocessors are also discussed