The paper presents the possibility of using the Kinect v2 module to control an industrial robot by means of gestures and voice commands. It describes the elements of creating software for off-line and on-line robot control. The application for the Kinect module was developed in the C# language in the Visual Studio environment, while the industrial robot control program was developed in the RAPID language in the RobotStudio environment. The development of a two-threaded application in the RAPID language allowed separating two independent tasks for the IRB120 robot. The main task of the robot is performed in Thread No. 1 (responsible for movement). Simultaneously, Thread No. 2 ensures continuous communication with the Kinect system and provides information about the gesture and voice commands in real time without any interference in Thread No. 1. The applied solution allows the robot to work in industrial conditions without the negative impact of the communication task on the time of the robot’s work cycles. Thanks to the development of a digital twin of the real robot station, tests of proper application functioning in off-line mode (without using a real robot) were conducted. The obtained results were verified on-line (on the real test station). Tests of the correctness of gesture recognition were carried out, and the robot recognized all programmed gestures. Another test carried out was the recognition and execution of voice commands. A difference in the time of task completion between the actual and virtual station was noticed; the average difference was 0.67 s. The last test carried out was to examine the impact of interference on the recognition of voice commands. With a 10 dB difference between the command and noise, the recognition of voice commands was equal to 91.43%. The developed computer programs have a modular structure, which enables easy adaptation to process requirements.

The paper presents the identification process of the mathematical model parameters of a differential-drive two-wheeled mobile robot. The values of the unknown parameters of the dynamics model were determined by carrying out their identification offline with the Levenberg-Marguardt method and identification online with the Recursive least-squares method. The authors compared the parameters identified by offline and online methods and proposed to support the recursive least squares method with the results obtained by offline identification. The correctness of the identification process of the robot dynamics model parameters, and the operation of the control system was verified by comparing the desired trajectories and those obtained through simulation studies and laboratory tests. Then an analysis of errors defined as the difference between the values of reference position, orientation and velocity, and those obtained from simulations and laboratory tests was carried out. On itd basis, the quality of regulation in the proposed algorithm was determined.

The paper presents the step by step process of modelling the movement of dispersed group of mobile robots using the MATLAB Simulink and Simscape Multibody software. As a modelled object, a group of laboratory robots, TurtleBot2, was adopted. First, the construction of a robot CAD model was described. Next, the control system developed in Simulink was described. At the end, the robot components were defined in Simscape Multibody and a group movements analysis was carried out.

In this paper, the implementation of the trajectory tracking control strategy on a ROS-based mobile robot is considered. Our test-bench is the nonholonomic mobile robot 'TURTLEBOT'. ROS facilitates considerably setting-up a suitable environment to test the designed controller. Our aim is to develop a framework using ROS concepts so that a trajectory tracking controller can be implemented on any ROS-enabled mobile robot. Practical experiments with 'TURTLEBOT' are conducted to assess the framework reliability.

The article presents issues related to an experimental study of the vibrations of a roller shutter gripper on a robotic palletizing station. The authors presented the developed and built construction of the gripper for handling whole layers of products, separators, and pallets. The concept of the device was developed in cooperation with an integrator company. The authors verified the functionality of the gripper in a virtual environment for modeling and programming industrial robots. After the gripper was manufactured and the control software was developed for it, functional tests and inertia tests were carried out. The main purpose of the tests was to determine the vibration of the robot’s flange and the vibration of the attached gripper. Tests of the gripper’s properties on the robotic test bench were performed using MTi XSENS sensors and a PHANTOM V210 high-speed camera. The testing methodology proposed by the authors made it possible to confirm the occurrence of vibrations in the structure and to determine the relationship between the parameters of the robot’s motion (velocity and acceleration) and the magnitude of the vibrations occurring. During the tests, a disturbance in the decrease in the maximum value of acceleration was noted. This may be due to the appearance of natural vibrations in the structure. They have a damped character; however, they are not steady. In future work, the authors will focus on the possibility of using the proposed methodology to reduce robot vibrations in selected robotic production processes (such as spot welding).

The most common cause of diseases in swimming pools is the lack of sanitary control of water quality; water may contain microbiological and chemical contaminants. Among the people most at risk of infection are children, pregnant women, and immunocompromised people. The origin of the problem is a need to develop a system that can predict the formation of chlorine water disinfection by-products, such as trihalomethanes (THMs). THMs are volatile organic compounds from the group of alkyl halides, carcinogenic, mutagenic, teratogenic, and bioaccumulating. Long-term exposure, even to low concentrations of THM in water and air, may result in damage to the liver, kidneys, thyroid gland, or nervous system. This article focuses on analysis of the kinetics of swimming pool water reaction in analytical device reproducing its circulation on a small scale. The designed and constructed analytical device is based on the SIMATIC S7-1200 PLC driver of SIEMENS Company. The HMI KPT panel of SIEMENS Company enables monitoring the process and control individual elements of device. Value of the reaction rate constant of free chlorine decomposition gives us qualitative information about water quality, it is also strictly connected to the kinetics of the reaction. Based on the experiment results, the value of reaction rate constant was determined as a linear change of the natural logarithm of free chlorine concentration over time. The experimental value of activation energy based on the directional coefficient is equal to 76.0 $[kJ\times {mol}^{-1}]$. These results indicate that changing water temperature does not cause any changes in the reaction rate, while it still affects the value of the reaction rate constant. Using the analytical device, it is possible to constantly monitor the values of reaction rate constant and activation energy, which can be used to develop a new way to assess pool water quality.