Hybrid Event

Event program

Friday, 5/24/2024 9:00 AM - 12:30 PM, Collegium, Grand hotel Adriatic, Opatija 9:00 AM - 10:30 AM Papers  1. S. Kimathi, B. Lantos (Budapest University of Technology and Economics, Budapest, Hungary) Integrated Path Tracking, and Control of a Fixed Wing UAV based on Dual Quaternions Parameterized Dynamics  Based on the dual quaternion formalism, the dynamics of a fixed wing UAV are formulated for path tracking. A control strategy is developed by exploiting the logarithmic map of the unit dual quaternion so as to ensure global asymptotic stability in the three-dimensional space. The control and stabilization of the UAV, is carried out using dual quaternion dynamics such that a state feedback control law using a PD controller ensures the simultaneous attitude and position tracking. Simulation results are presented to illustrate the applicability of this integrated approach in the tracking of an omnidirectional path using a fixed wing UAV. 2. V. Diklic (FER, Đakovo , Croatia), B. Novoselnik (FER, Zagreb, Croatia) Comparison of Linear and Nonlinear Model Predictive Control for Vehicle Path Following  This technical paper investigates and compares the performance of two model predictive control algorithms employed in the control of a ground vehicle. Both predictive controllers are based on a simplified bicycle model of the vehicle. The main difference is that one controller uses a nonlinear version of the bicycle model and the other one further simplifies it by linearizing it around the operating point. The study centers around evaluating the controllers’ effectiveness in a dynamic scenario through the execution of a double-lane change maneuver. By assessing trajectory tracking and computational efficiency, this paper aims to delineate the impact of linearization choices on the controllers’ overall performance. Both controllers are extensively tested in realistic simulations on a full nonlinear multi-body model of the vehicle sourced from the CommonRoad Python library. The results of these simulations provide insights into the trade-offs between model accuracy and computational complexity. 3. B. Ćaran, N. Škifić, V. Milić, M. Švaco (Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Zagreb, Croatia) Application of a Time-Varying Linear Quadratic Controller for Trajectory Tracking of a Four-Wheel Mobile Robot with Independent Steering and Drive  This paper is concerned with the design of a controller for trajectory tracking of a mobile robot with four steerable and four independently driven wheels (4WIS4WID). Taking into account the appropriate assumptions, the kine matic equations of the robot are converted into three-input, two-chain, single-generator chained form. After that, for a small perturbations around the reference trajectory, an approximate linearization of the chained form is performed. This procedure led to the form of a time-varying system suitable for the synthesis of a time-varying linear control law according to the quadratic optimality criterion. The version of the control law which gives the best results is determined by computer simulations in a mathematical software package MATLAB (MathWorks, Natick, MA, USA). The obtained control law is applied to the experimental set-up of a mobile robot developed at the Regional Center of Excellence for Robotic Technology (CRTA). The controller is implemented using Robot Operating System (ROS) and experimental measurements are performed using the OptiTrack system. 4. L. Orbegoso Moreno, E. Valverde Ramírez, J. Ruiz Rodríguez, I. Miñano Corro (National University of Trujillo, Trujillo, Peru) An Integrated Approach to Robotic Joint Interpolation: Kinematic Modeling and Constraints for Smooth Trajectories  This paper introduces a direct trajectory planning approach for manipulator robots, seamlessly transitioning from the task space to the robot joint space, while adhering to kinematic (joint position and velocity boundaries) and dynamic (torque limits) constraints. The method employs state-space modeling with joint positions and their derivatives up to order n-1 as variables, utilizing the nth derivative of joint positions as the control signal for continuity and differentiability during interpolation. The state-space model outputs forward and differential kinematics, enabling interpolation with consideration for position and velocity constraints in the task space. Optimal control signal computation, derived via quasi-Newton optimization and its nth integration using the Cauchy formula, facilitates the determination of joint values over time. Finally, the proposed method was validated on the ABB-IRB-120 robot model, where it demonstrated a unified solution for task-space path planning under both kinematic and dynamic constraints. 5. L. Patrlj, B. Novoselnik, M. Baotić (Faculty of Electrical Engineering and Computing, Zagreb, Croatia) Comparison of Linear and Nonlinear Controllers on a Mechatronic System  This technical paper presents the application of various control methods on a mechatronic laboratory setup of a rotary inverted pendulum. The full nonlinear dynamic model of the pendulum is obtained using Euler-Langrange method and it is further simplified for the purpose of designing different controllers for stabilization of the pendulum in the upright position. In particular, we compare two nonlinear control methods (sliding mode control and model predictive control) to two classical linear control methods (proportional-derivative control and linear-quadratic control). All considered control methods are briefly explained and corresponding controllers are derived and tested on the experimental setup. 10:30 AM - 11:00 AM Break  11:00 AM - 12:30 PM Papers  1. L. Giannini, A. Buzzin (Sapienza, University of Rome, Rome, Italy), G. Bocchetta, A. Scorza (Department of Industrial, Electronic and Mechanical Engineering, Roma Tre University, Rome, Italy), G. de Cesare (Sapienza, University of Rome, Rome, Italy), N. Belfiore (Department of Industrial, Electronic and Mechanical Engineering, Roma Tre University, Rome, Italy), R. Asquini (Sapienza, University of Rome, Rome, Italy) Performance Evaluation of a MEMS Compact Electrostatic Microgripper Equipped with Rotary Comb Drives and Curved Flexure Hinges  Microgrippers are MEMS devices designed for handling and manipulating objects at a microscopic scale. In this work, a microgripper equipped with curved flexure hinges is presented, with a design specifically aimed at improving its grasping capabilities with respect to those found in literature, while maintaining a small overall footprint of 15 mm2, and an established fabrication procedure (silicon-on-insulator technology). It is electrostatically actuated through five rotary comb-drives made of interdigitated fingers. Finite Element Analysis has been adopted to analyze the system performance when voltage is applied. As main figures of merit, the tip displacement and rotation, the maximum stress sustained by the flexure hinges and the maximum operating voltage (MOV) were investigated. A tip displacement up to 39 μm and a tip rotation of 1° were achieved at 15 V of MOV, better than other electrostatically driven microgrippers presented in literature, enabling the manipulation of objects ranging from a few microns to tens of microns in size with relatively low voltage, and suggesting its use in the field of integrated micromanipulation and micro-surgery. 2. N. Borzić, D. Dubinović, L. Roy Sabolić, Đ. Nađ (Sveučilište u Zagrebu Fakultet elektrotehnike i računarstva, Zagreb, Croatia) Small Surface Vessel for Multi-Robot Systems Education  The paper will present the student work that involves creating an autonomous surface vessel (ASV) for internal (pool) use. The vessel is a modification of a cheap speed boat that allows integration into the pool infrastructure enabling camera tracking and data fusion from the onboard inertial measurement unit. This modification involved hardware development from thruster propulsion control, WiFi connectivity and software development from filtering of cheap onboard inertial units to image processing for detecting and tracking multiple ASVs within the camera. Due to limited availability of such small platforms for the marine research and education sector, the main paper contribution is the through presentation of a budget do-it-yourself modification for creating a controllable ASV that can be used for multi-robot education purposes from high-school to master level. 3. M. Orić, V. Galić, F. Novoselnik (Protostar Labs, Osijek, Croatia) Simulator for UAV Localization and Navigation in Various GPS-Denied Scenarios  There is a steady increase in use of unmanned aerial vehicles (UAVs) in many industries. The rise in the use of UAVs requires increased stable localization and navigation algorithms to ensure safe operation. Some industries demand successful work of UAVs in areas without GPS, for example, drone operation in warehouses with metal roofs. Safe operation of UAVs includes successful “Return To Home” (RTH) protocols retaining aircraft operation stability after losing signal and successfully finding the way back to the flight starting point. Development of a reliable UAV localization and navigation system is challenging due to the high dependence on manual work and safety concerns. To mitigate these limitations, we developed a UAV simulation pipeline that can be used for localization and navigation algorithm testing. The pipeline uses ROS and connects algorithms with a 3D environment simulator and provides a graphical interface for easy operation. Users have the ability to input waypoints for the trajectory, start the simulation, limit the GPS signal dynamically, and estimate the success of return. By changing the environment, trajectory shape, and length, various scenarios can be tested. Simulations of RTH success with realistic constraints promise to preserve resources in the testing stage of the UAVs decreasing security risks. 4. L. Mestric, P. Curkovic (Faculty of Mechanical Engineering and Naval Architecture, Zagreb, Croatia) Comparative Analysis of Topology Optimization Platforms for Additively Manufactured 6 DOF Robot Arms  Topology optimization (TO) is increasingly integrated into commercial CAD environments due to the ease and cost-effectiveness of manufacturing complex freeform geometries using additive technologies. Although the underlying TO theory is well-established, various topology optimization systems yield different results. This paper conducts a systematic evaluation and cross-analysis of five representative TO platforms using elements of a six degrees of freedom (6 DOF) robotic arm as a case study. To assess the practical implications, the most successfully optimized components are 3D printed and assembled into a functional robotic arm. The evaluation criteria, including postprocessing requirements, energy efficiency, price, and manufacturability of optimized vs. unoptimized parts, are discussed. The platforms are then ranked based on these criteria. 5. J. Maltar, D. Ševerdija (School of Applied Mathematics and Informatics, J. J. Strossmayer University of Osijek, Osijek, Croatia) LiDAR-based SLAM in a 2D Simulated Environment  One of the best-known problem in robotics is simultaneous localization and mapping where the robot tries to build the map of a place it navigates while simultaneously determines its configuration in that space. Different sensor modalities, e.g., LiDAR sensor(s) or visual sensor(s) or their combination, can be utilized in order to tackle this problem. Configurations of the robot over time are estimated by using standard estimation techniques such as the extended Kalman filter or factor graphs. Unfortunately, one of the main issues during the robot’s movement is drift that occurs due to imperfect sensors and actuators. This can be diminished by deploying a loop closing algorithm that detects whether an already visited place has been observed. That being said, a SLAM implementation itself has a steep learning curve. Therefore, in this paper we provide an extensive overview of all the steps needed to implement such a system. Also, we provide an extensive quantitative evaluation of our approach where we deployed our state-of-the-art loop closing algorithm that diminishes drift. We shown how our loop closing approach improves the absolute trajectory error measure when compared to the standard approach.

Basic information:

Andrej Jokić (Croatia), Marko Švaco (Croatia)

Tadej Bajd (Slovenia), Ante Bakić (Croatia), Ricardo Branco (Portugal), Bojan Jerbić (Croatia), Zlatko Katalenić (Slovenia), Igor Kotenko (Russia), Zdenko Kovačić (Croatia), Danica Kragić Jensfelt (Sweden), Duc Truong Pham (UK), Vincenzo Piuri (Italy), Ioan Sacala (Romania), Bruno Siciliano (Italy), Karolj Skala (Croatia), Uroš Janez Stanič (Slovenia), Zorislav Šojat (Croatia)

Andrej Jokić
University of Zagreb
Faculty of Mechanical Engineering and Naval Architecture
Ivana Lucica 5
HR-10000 Zagreb, Croatia

Phone: +385 92 1013 815
E-mail: andrej.jokic@fsb.hr

Accepted papers will be published in the ISSN registered conference proceedings. Papers in English presented at the conference will be submitted for inclusion in the IEEE Xplore Digital Library. 
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There is a possibility that the selected scientific papers with some further modification and refinement are being published in the following journals: Journal of Computing and Information Technology (CIT), MDPI Applied Science, MDPI Information Journal, Frontiers and EAI Endorsed Transaction on Scalable Information Systems.

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