The article presents a method of programming robots using virtual reality and digital twins. The virtual environment is a digital twin of a robotic station, built based on CAD models of existing station elements. The virtual reality system is used to record human movements in a virtual environment, which are then reproduced by a real robot. The method developed is dedicated mainly to such situations in which it is necessary for the robot to reproduce the movements of a human performing a process that is complicated from the point of view of robotization. An example of using the method for programming a robot implementing the process of cleaning ceramic casting moulds is presented.
25 March 2019 in Archive of Mechanical Engineering
The article presents the issue of calibration and verification of an original module, which is a part of the robotic turbojet engines elements processing station. The task of the module is to measure turbojet engine compressor blades geometric parameters. These type of devices are used in the automotive and the machine industry, but here we present their application in the aviation industry. The article presents the idea of the module, operation algorithm and communication structure with elements of a robot station. The module uses Keyence GT2-A32 contact sensors. The presented information has an application nature. Functioning of the module and the developed algorithm has been tested, the obtained results are satisfactory and ensure sufficient process accuracy. Other station elements include a robot with force control, elements connected to grinding such as electrospindles, and security systems.
The aim of this paper is to present examples and original solutions related to the application of the digital twin concept in designing safety systems for robotic stations. This paper includes a review of publications on robot safety systems and digital twins. Based on this review, it was concluded that further work in this area is justified. This paper demonstrates the use of a digital model of a robotic casting mold preparation station to design safety components for an industrial cell. A key element of this paper is the presentation of developed algorithms and their applications in building digital twins of existing robotic stations. By characterizing advanced safety systems used in robotic stations, an example of using a digital twin of a robotic station to create safety zones and so-called restricted zones for the robot was developed. As part of the research conducted, a real, comprehensive example of creating safety zones based on the robot’s TCP paths was carried out.
This article deals with the design and creation of digital twins of robotic stations. A literature review of digital twins, robot programming methods and laser tracker applications is presented. This paper shows that the construction of digital twins is closely related to one of the most popular methods of robot programming, i.e., off-line programming. In the case of digital twins of robotic stations, modeling accuracy and two-way communication with the real station proved to be crucial. The article proposes a methodology for solving the basic problem of off-line robot programming, i.e., the limited accuracy of the representation of the station and the details. The algorithm of proceeding in the case when the station already exists and its digital model is built and the case when the digital model is first created and the real solution is built on its basis is shown. According to the developed methodology, a digital twin of a real robotic station was created and the possibilities arising from the use of virtual tools were shown. The developed digital twin has the ability to communicate with advanced Matlab 2021-type tools, uses cloud solutions and virtual and augmented reality for training, simulates physical phenomena and provides the ability to accurately program robots off-line.
Vibration analysis of industrial robots is one of the key issues in the context of robotisation of machining processes. Low-frequency vibrations result from flexibility in manipulator joints. Within the scope of the article, a model of a two-link robot manipulator was built. Dynamic equations of motion were formulated to study the influence of the robot arm configuration on vibration effects. Based on numerical simulations, the frequency spectrum of vibrations of the robot’s links was determined, and tests were carried out in a number of configurations, obtaining a map of resonant frequencies depending on the configuration of the manipulator. Experimental studies were then carried out, which confirmed the conclusions from the simulation studies. The results obtained confirm that the positioning of the manipulator’s links has a significant effect on vibration effects. Tests conducted using a vision system with a motion amplification application made it easier to interpret the results. The formulated mathematical model of the manipulator generates results that coincide with the results of experimental studies.
Aircraft engine blades are produced through various techniques, one of which is precise electrochemical machining (ECM), commonly applied in the aerospace, automotive, and electromechanical industries. This method achieves machining accuracy ranging from 0.1 to 0.3 mm. However, components with complex shapes still require grinding and polishing. During the grinding of aircraft blades, achieving high precision and maintaining strict dimensional control are essential. This involves monitoring the thickness of the blade at key cross-sections, as well as the radii of the leading and trailing edges, chord lengths, twist angles, and more. The paper introduces a developed robotic blade grinding process featuring iterative laser measurement of geometric parameters. A custom measuring device with laser heads was designed, calibrated, and tested for repeatability. The measurement data were then used to determine the blade feed rate and machining path via a fuzzy logic decision system. The proposed method was validated on a series of PT6 aircraft engine blades in collaboration with Pratt and Whitney Rzeszów.