Abstract: The aim of the article is to give an overview of human factor research in psychology applicable to autonomous driving. The study is centered around situation awareness, a widely used concept in human factor research regarding the operation of automated and semi-automated systems (and communication between autonomous vehicles and humans). A proposal is put forward for structuring situation awareness requirements for autonomous driving, which could be a starting point for defining such requirements, and may foster a discussion on the issues associated with the human factor in relation to autonomous driving. Two models of human error (the SHELL model and the Swiss cheese model) are also introduced, one of which represents an integrated approach of error in situations that involve humans working with complex machinery or instruments, while the other represents a more superficial viewpoint on the multicausal nature of errors. The present overview can provide an appropriate basis for a discussion about the role of the driver in autonomous vehicles, and the place of human factor research in the emerging field of self-driving technology.

Keywords: autonomous car, self-driving car, situation awareness, human factor, human error

Abstract: Computer vision-based approaches have become more common in assistance systems for the blind and visually impaired where portable devices can be used to assist users in their free movement. The method for pedestrian crosswalk detection with the main goal to facilitate the crossing of the road is proposed in this paper. The proposed crosswalk detection method is based on analyzing the image column and row structure. The Performance of this kind of approach relies on the input image resolution and quality. Therefore, guidance for selecting the appropriate input image resolution for this kind of approach is given. This approach is tested on the realistic input data captured with a monocular camera and using portable devices for image processing.

Keywords: assistance systems for the visually impaired; crosswalk detection; column structure; morphology

Abstract: There is already a lot of research in the literature on the binary separation of healthy people and people with some illnesses that affects speech. However, there are only a few examinations where more illnesses are recognized together. The examination of the latter is justified by the fact that a person may suffer from several illnesses at the same time to a certain extent. In the present study, multiclass classification of depression, Parkinson’s disease, and general voice disorders (organic and functional dysphonia) was performed using speech samples. Foremost, several acoustic features were examined as input (such as Mel-Frequency Cepstral Coefficients (MFCCs), mel-band energy values, formants and their bandwidths). Using the inputs, auto- and cross-correlation structures were formed as image representations and fed to a convolutional neural network (CNN). Parameter optimization of the correlation structures and the CNN model was applied to achieve the highest accuracy. Moreover, the result of the tuned process was compared to the result of a baseline process. Finally, multiclass (5 and 4 classes) classification was performed with the best parameters. The prominent feature set was the MFCCs (55.9% accuracy, 52.2% macro F-score) for 5 class classification. 64.3% accuracy and 60.0% macro F1-score was obtained for 5 classes after parameter optimization. For classifying 4 classes (merging dysphonic ones together), 74.9% accuracy and 71.7% macro F1-score was achieved.

Keywords: depression; voice disorders; Parkinson’s disease; speech; Convolutional Neural Network

Abstract: Recently finite control set model predictive control (FCS-MPC) becomes a promising solution for controlling power electronics devices (PEDs). Although FCS-MPC produces variable switching frequency and steady-state error, it has many advantages such as the ease of implementation, controlling multiple parameters at the same time, and generating the switching signals internally. This paper aims to assess the performance of the FCS-MPC by constructing a comparative study of the FCS-MPC current control with the proportional-integral (PI) current control. For a fair comparison, the FCS-MPC average switching frequency was made to be equal or lower than the PI switching frequency. The study was performed on three different grid-connected PEDs, which are the three-phase two-level, single-phase full-bridge, and H5 inverters. Both control strategies were compared considering the switching frequency, common-mode voltage, leakage current, total harmonics distortion, and steady-state error. The results illustrate that the produced common-mode voltage and leakage current of the FCS-MPC are lower than PI in all cases. Even though FCS-MPC results in higher THD and steady-state error, they were maintained within acceptable limits. The three inverters and case studies were carried out to verify the performance of the controllers via the PSCAD/EMTDA software package.

Keywords: Model predictive control (MPC); Grid-connected inverters; Power electronics control; Common-mode voltage (CMV); Leakage current

Abstract: The paper introduces the PRISM methodology built on the critical characteristics of the traditional failure mode and effect analysis (FMEA) and the risk matrix (RM) risk assessment methodologies. The authors create a new definition in the risk assessment process, which is introduced as partial risk. The paper focuses on assessing the compliance risks, the risks of organizational wrongdoing, and legal non-compliance. A real-life case study from the banking sector shows the risk assessment process based on the PRISM method.

Keywords: risk assessment; FMEA; risk matrix; compliance management

Abstract: The use of free-form surfaces is becoming more common in everyday life. Ergonomic, aesthetic, aerodynamic and fluid dynamics aspects also help their spread. The paper examines the CAM aspects of machining the free-form surfaces with a ball-end milling tool. Different CAM strategies create different toolpaths. This makes it possible to examine the effect of the machining direction on the surface roughness, the shape accuracy and the profile error. Changes in cutting parameters have an effect on these properties too, which have been investigated. During the production of the test pieces, the milling forces were measured, from which important conclusions can also be drawn.

Keywords: free-form milling; ball-end milling; geometric tolerance; surface roughness; cutting force; CAM strategies

Abstract: The switched reluctance motors (SRMs) are gaining increasing interest in many industrial applications, including electric vehicles (EVs). However, their main drawback is the high torque ripple and noise. This paper presents an optimization-based method to improve the torque quality of SRM drives. The focus is on reducing torque ripple without complicating the control algorithm. The switching angles are optimized using a multistage ant colony algorithm (MSACA). The multistage algorithm provides a better search capability that fits appropriately with the high nonlinearities of SRMs. The finite element method (FEM) is employed to calculate the magnetic characteristics of the tested 8/6 SRM prototype. These characteristics are used within the MATLAB environment in the form of lookup tables to model the machine. The performance indices are calculated within the simulation model. Series of simulation results are included to show the effectiveness of the proposed control. Besides, experimental verification is also included to verify the theoretical findings.

Keywords: switched reluctance motor; finite element method; optimization; switching angles; ant colony algorithm

Abstract: In the presented paper a survey of currently used popular master manipulators solutions is given, pointing their advantages and disadvantages in the process. It is pointed that all widely available devices of such type are burdened with motion limitations which affect their utilization greatly. As a solution to this problem, a novel construction of a master manipulator device is being proposed. The design process of the device itself is being discussed, but also the description of a control system is presented along with the control algorithm and filtration method (Kalman filter). The publication is being concluded with the description of experiments performed along with results obtained.

Keywords: master manipulator; construction; control system

Abstract: This paper presents a wireless macrodiversity communication system consisting of a receiver for macrodiversity selection combining (SC) receiver and two microdiversity SC receivers operating over correlated Gamma shadowed Rayleigh multipath fading environment in the presence of co-channel interference subject to Rayleigh short-term fading. First, we derive expression for cumulative distribution function of output signals of the both microdiversity SC receivers, and then capitalizing on it, we evaluate outage probability of the macrodiversity reception. The obtained probability outage results, both numerical and those obtained by simulation, as well as, the influence of Gamma long-term severity parameter and the correlation coefficient, are graphically illustrated and discussed.

Keywords: selection combining (SC); Rayleigh fading; co-channel interference; Gamma shadowing; outage probability

Abstract: The notch impact test, that is used to determine the amount of absorbed energy consumed, for breaking materials, under dynamic forces, is among the various important material mechanical tests. The quality and reliability of the results obtained, as a result of the test, are of great value for laboratories. In this study, the parameters affecting the measurement quality in the notch impact test, are expressed as uncertainty values. Charpy notch impact test was performed for materials with different absorbed energy levels in the laboratory. The uncertainty values were calculated, according to the ISO 148-1 standard, from the data obtained. Then, the uncertainty values were analyzed and their effects on the uncertainty calculation were determined. Herein, it was concluded that the parameters should be determined and analyzed correctly, in order to minimize measurement uncertainties.

Keywords: Charpy test; uncertainty calculation; notch impact test; ISO 148-1

Abstract: In this report, we introduce a novel discrete calculus method for obtaining the numerical solution of parabolic and elliptic type partial differential equations. The discrete operators applied during the process of obtaining the numeric solution have the same advantageous properties as those of their continuous counterparts: orthogonality, conservation laws, and minimum-maximum principle. The results of our proposed solution method are interpreted in terms of the underlying physics and the material properties on the same graph. This can significantly simplify the solution of the discretised system that originates from the advantageous properties of discrete operators defined on weighted graphs. We demonstrate the applicability of the presented approach by using it to calculate the numeric solutions of an elliptic and a parabolic model problem and compare these results to the solutions of the same problems calculated using a well-known FEM solver.

Keywords: Discrete Calculus; Elliptic and Parabolic Problems; Differential Operators on Graphs; Lumped Elements

Abstract: With the growing pervasiveness of Virtual Reality, Augmented Reality, Mixed Reality and Digital Twins combined with Artificial Intelligence, 5G networks and the omni-present 2D Web, we are entering into a new era, characterized by a multi-modal entangled combination of previously disparate realms of IT with human and social cognitive systems. This process of entanglement is arguably leading to a new, qualitatively different kind of reality, in which the borders between the physical and digital world, as well as digital representations and simulations thereof are becoming increasingly fuzzy. Based on these developments, the paper re-interprets some well-known concepts - including virtual reality, augmented reality, mixed reality, as well as virtual / digital simulations and virtual / digital twins. Based on these new interpretations, the paper introduces the higher-level structures of Digital Reality (DR) and Internet of Digital Reality (IoD). It is argued that these structures can lead to a better understanding of the new possibilities afforded to humanity by pervasive digital technologies.

Keywords: Digital Reality; Future Internet; Internet of Things; Internet of Everything; Internet of Digital Reality