Digital Twins, Virtual Devices, and Augmentations for Self-Organising Cyber-Physical Collectives

The engineering of large-scale cyber-physical systems (CPS) increasingly relies on principles from self-organisation and collective computing, enabling these systems to cooperate and adapt in dynamic environments. CPS engineering also often leverages digital twins that provide synchronised logical counterparts of physical entities. In contrast, sensor networks rely on the different but related concept of virtual device that provides an abstraction of a group of sensors. In this work, we study how such concepts can contribute to the engineering of self-organising CPSs. To that end, we analyse the concepts and devise modelling constructs, distinguishing between identity correspondence and execution relationships. Based on this analysis, we then contribute to the novel concept of “collective digital twin” (CDT) that captures the logical counterpart of a collection of physical devices. A CDT can also be “augmented” with purely virtual devices, which may be exploited to steer the self-organisation process of the CDT and its physical counterpart. We underpin the novel concept with experiments in the context of the pulverisation framework of aggregate computing, showing how augmented CDTs provide a holistic, modular, and cyber-physically integrated system view that can foster the engineering of self-organising CPSs.

Smartphone display size can influence perceptual judgments

Classic research in perception has suggested that visual context can impact how individuals perceive object characteristics like physical size. The current set of studies extends this work to an applied setting by examining whether smartphone display size can impact the perception of objects presented on smartphones. Participants viewed several target items, on two different sized virtual device displays based on actual consumer devices and were asked to make simple judgments of the size of presented objects. Results from both experiments confirm that display size impacts perceived size, such that larger displays cause users to significantly underestimate the size of objects moreso than smaller displays. This is the first study to confirm such an effect, and suggests that beyond aesthetics or cost, one’s personal choice of device might have additional performance consequences.

Human Teleoperation - A Haptically Enabled Mixed Reality System for Teleultrasound

<div> <div> <div> <p>Current teleguidance methods include verbal guidance and robotic teleoperation, which present tradeoffs between precision and latency versus flexibility and cost. We present a novel concept of "human teleoperation" which bridges the gap between these two methods. A prototype teleultrasound system was implemented which shows the concept’s efficacy. An expert remotely "teloperates" a person (the follower) wearing a mixed reality headset by controlling a virtual ultrasound probe projected into the person’s scene. The follower matches the pose and force of the virtual device with a real probe. The pose, force, video, ultrasound images, and 3-dimensional mesh of the scene are fed back to the expert. In this control framework, the input and the actuation are carried out by people, but with near robot-like latency and precision. This allows teleguidance that is more precise and fast than verbal guidance, yet more flexible and inexpensive than robotic teleoperation. The system was subjected to tests that show its effectiveness, including mean teleoperation latencies of 0.27 seconds and errors of 7 mm and 6◦ in pose tracking. The system was also tested with an expert ultrasonographer and four patients and was found to improve the precision and speed of two teleultrasound procedures. </p> </div> </div> </div>

Human Teleoperation - A Haptically Enabled Mixed Reality System for Teleultrasound

<div> <div> <div> <p>Current teleguidance methods include verbal guidance and robotic teleoperation, which present tradeoffs between precision and latency versus flexibility and cost. We present a novel concept of "human teleoperation" which bridges the gap between these two methods. A prototype teleultrasound system was implemented which shows the concept’s efficacy. An expert remotely "teloperates" a person (the follower) wearing a mixed reality headset by controlling a virtual ultrasound probe projected into the person’s scene. The follower matches the pose and force of the virtual device with a real probe. The pose, force, video, ultrasound images, and 3-dimensional mesh of the scene are fed back to the expert. In this control framework, the input and the actuation are carried out by people, but with near robot-like latency and precision. This allows teleguidance that is more precise and fast than verbal guidance, yet more flexible and inexpensive than robotic teleoperation. The system was subjected to tests that show its effectiveness, including mean teleoperation latencies of 0.27 seconds and errors of 7 mm and 6◦ in pose tracking. The system was also tested with an expert ultrasonographer and four patients and was found to improve the precision and speed of two teleultrasound procedures. </p> </div> </div> </div>

COMPACT ROTARY PLATFORM AS A UNIVERSAL LABORATORY STAND

A single axis rotary platform is distinguished among the laboratory equipment for testing gyroscopic devices and systems and their sensitive elements. An overview of the design principles of industrially developed stands for the study of static and dynamic characteristics of gyroscopic devices and systems is provided. The scheme of design of the universal laboratory stand is suggested as the compact rotary platform for research of static and dynamic characteristics of micromechanical gyroscopes and accelerometers as sensors of angular speed. The physical components of such a stand and technical and technological problems of its practical implementation are reviewed. The proposed laboratory stand is considered as a cyberphysical system where computing components play a crucial role in determining the parameters of the system and the studied micromechanical sensors. For this purpose, in addition to the physical control loop of the electric drive to ensure the stability of the angular velocity of the platform, an independent measuring loop is considered for analytical determination of system parameters, including the studied micromechanical sensors. The versatility of the stand is ensured by solving the inverse problems, namely determining in the process of testing static and dynamic characteristics of the electric drive and measuring sensors that work on various physical principles. It is assumed that, in addition to solving practical problems of micromechanical sensors in the development of the appropriate information interface of the virtual device, a compact laboratory stand can be effectively used in the educational process during laboratory work in relevant disciplines of instrument making direction.

A Comparison of Three Ways to Measure Time-Dependent Densities With Quantum Simulators

Quantum algorithms are touted as a way around some classically intractable problems such as the simulation of quantum mechanics. At the end of all quantum algorithms is a quantum measurement whereby classical data is extracted and utilized. In fact, many of the modern hybrid-classical approaches are essentially quantum measurements of states with short quantum circuit descriptions. Here, we compare and examine three methods of extracting the time-dependent one-particle probability density from a quantum simulation: direct Z-measurement, Bayesian phase estimation, and harmonic inversion. We have tested these methods in the context of the potential inversion problem of time-dependent density functional theory. Our test results suggest that direct measurement is the preferable method. We also highlight areas where the other two methods may be useful and report on tests using Rigetti's quantum virtual device. This study provides a starting point for imminent applications of quantum computing.

Bond-Graph model based stepper motor output characteristics simulation implemented in LabVIEW environment

In the industry, simulations are of great importance. They enable measurements to be made in different conditions about a virtual device, which are highly comparable to measurements made in a real life scenarios. Because of their wide range of usage in lower power drive systems, where precision and simplicity is a must, the subject of study is a permanent magnet stepper motor. For precise positioning purposes, it is essential to know the positioning behaviour of these devices. The model construction process involved an intermediate step, which consisted of creating the Bond-Graph of the motor based on pre-defined models available in the literature in this field. In the next step, the Bond-Graph model was converted to a block diagram of the motor. This permitted the direct implementation of the motor model in LabVIEW visual programming environment. The preliminary steps allows us to check and confirm the functionality and correctness of the model. This article covers in detail the model conversion and implementation steps of the simulation. At the end, the functionality of the simulation was tested.

Computer system for metrological testing of location sensors used to monitor the patient's condition in magnetotherapy

Non-contact monitoring of vital signs of a person is a reliable and safe way of promptly obtaining objective diagnostic information about the current physiological state of a patient during surgical operations, physiotherapeutic procedures or during sleep. The absence of direct contact of the sensors with the patient's body makes it possible to exclude the influence of a number of interfering factors, such as a violation or weakening of contact, which can lead to a deterioration in the quality of signals from the output of the sensors, a long-term location of the sensors on the body can have a psychological effect on the patient, changing his condition and thereby distorting the treatment method, etc. In order for the results of monitoring and diagnostics to be reliable and guaranteed accurate, it is necessary to carry out periodic metrological certification of location sensors, especially since many of them are of foreign production and their characteristics are either not standardized or do not meet the requirements of their operating conditions. Therefore, the tasks of developing methods and means for carrying out metrological tests of non-contact sensors for medical purposes are becoming urgent. Purpose – to show the possibility of implementing automated metrological tests of location sensors for medical use based on a personal computer and publicly available standard hardware and software. A method has been developed and implemented for conducting metrological tests of location sensors based on a personal computer, a digital dynamic measure of linear displacement, virtual measuring instruments, laser and ultrasonic sensors, as well as determining conversion errors in the LabVIEW environment. As an exemplary measuring instrument, it is proposed to use a webcam with a virtual device for recording the law of displacement in the LabVIEW Vison Development application. Full-scale experiments have been carried out, in which, using a digital measure of linear displacement, it is possible to reproduce with high accuracy almost any law of displacement and to regulate its informative parameters. Real movement signals were received with the help of virtual devices, recorded by two location sensors and a web camera. The errors of the means of registration are determined in comparison with the given digital method and analytically the law of movement. Introduction of the developed method and hardware and software for metrological certification of sensors of diagnostic channels of the systems of complex magnetotherapy «Multimag» and «Relaxmag». Carrying out automated metrological tests of sensors will ensure prompt, reliable and objective control of their actual characteristics, which means it will increase the effectiveness of treatment due to the prompt and continuous monitoring of the patient's functional state and an objective assessment of a number of important indicators.