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- User-Experience with Haptic Feedback Technologies and Text Input in Interactive Multimedia DevicesPublication . Silva, Bruno; Costelha, Hugo; C. Bento, Luis; Barata, Marcio; Assuncao, PedroRemote control devices are commonly used for interaction with multimedia equipment and applications (e.g., smart TVs, gaming, etc.). To improve conventional keypad-based technologies, haptic feedback and user input capabilities are being developed for enhancing the UX and providing advanced functionalities in remote control devices. Although the sensation provided by haptic feedback is similar to mechanical push buttons, the former offers much greater flexibility, due to the possibility of dynamically choosing different mechanical effects and associating different functions to each of them. However, selecting the best haptic feedback effects among the wide variety that is currently enabled by recent technologies, remains a challenge for design engineers aiming to optimise the UX. Rich interaction further requires text input capability, which greatly influences the UX. This work is a contribution towards UX evaluation of remote control devices with haptic feedback and text input. A user evaluation study of a wide variety of haptic feedback effects and text input methods is presented, considering different technologies and different number of actuators on a device. The user preferences, given by subjective evaluation scores, demonstrate that haptic feedback has undoubtedly a positive impact on the UX. Moreover, it is also shown that different levels of UX are obtained, according to the technological characteristics of the haptic actuators and how many of them are used on the device.
- Monocular Camera Calibration for Autonomous Driving — a comparative studyPublication . Martins, Pedro Filipe; Costelha, Hugo; Bento, Luís Conde; Neves, CarlosAutonomous driving is currently a widely researched topic worldwide. With a large research effort being taken by industrial research units in the automotive sector, it is no longer exclusive to academic research labs. Essential to this ongoing effort towards level-5 vehicle autonomy, are the sensors used for tracking and detection, mainly lasers, radars and cameras. Most of the cameras for automotive application systems use wide-angle or fish-eye lens, which present high distortion levels. Cameras need to be calibrated for correct perception, particularly for capturing geometry features, or for distance-based calculations. This paper describes a case-study concerning monocular camera calibration for a small scale autonomous driving vehicle vision system. It describes the fundamentals on camera calibration and implementation, with results given for different lenses and distortion models. The aim of the paper is not only to provide a detailed and comprehensive review on the application of these calibration methods, but to serve also as a reference document for other researchers and developers starting to use monocular vision in their robotic applications.
- Subjective Evaluation of Haptic Feedback Technologies for Interactive MultimediaPublication . Silva, Bruno; Costelha, Hugo; Bento, Luís Conde; Barata, Márcio; Assunção, Pedro A. AmadoCurrent trends in the development of remote control devices for user interaction with multimedia equipment and applications are increasingly advancing the traditional keypad-based technologies, in order to improve the functionality of remote control devices and also to enhance the user experience. Haptic feedback allows the user to have a similar sensation to that provided by conventional buttons, with the advantage of a much greater flexibility, including dynamic choice of mechanical effects capable of discriminating between different functions. However, selection of haptic feedback effects that are capable of enhancing the user experience remains a great challenge for engineers and product designers. This work is a contribution towards this goal by presenting a usability study of two technologies (eccentric rotating mass and linear resonant actuator) capable of providing different haptic feedback effects in remote control devices. A subjective evaluation study was carried out to obtain subjective scores for a significant number of haptic feedback effects. The number of preferred actuators of each type and whether haptic feedback is suitable in remote control devices for interactive multimedia, were also evaluated. The results of this study show that most users prefer an interface with haptic feedback and different scores were obtained for different haptic feedback effects, according to the characteristics and number of the actuators.
- Arduino based Open Source Electronic Control Unit for Electric Utility VehiclesPublication . Francisco, Alexandre; Lopes, Nuno Vieira; Conde Bento, Luis; Ferreira, CarlosThis paper presents the design and development of a low-cost Electronic Control Unit (ECU), aimed for the application and control of Electric Utility Vehicles (EUV). The selection of components and features, as well the design and project of all the necessary hardware, was also carried out. The major features that overcome other available solutions are: multiple Controller Area Network (CAN) buses, electrical isolation of inputs, outputs, two CAN buses and serial interface, outputs with current feedback and its reduced overall cost. Validation tests were conducted in order to verify all functionalities. Moreover, an electric vehicle simulator was developed to assess the performance of the ECU in a real world working environment. The fully functional prototype of the ECU proved to be robust and experimental results fulfill the proposed objectives.
- Point Cloud Alignment for Deposited Material Assessment in Tunnel EnvironmentsPublication . Teixeira, Abel; Costelha, Hugo; Neves, Carlos; Bento, Luis CondeThe assessment of deposited material in tunnel reinforcement operations can be performed using a 3D model generated from multiple scans. For this purpose, an accurate alignment of the scanned models is required. Aligning existing structure model with data scanned after surface deformations can be challenging, particularly if reference markers are not available or were displaced. For scenarios where the surrounding structure is largely changed, certain procedures can be adapted when processing the scanned data to achieve consistent alignment between scanned and reference structure models. This work proposes a methodology to cope with these situations, analysing the impact of different approaches. Experiments were performed in a realistic scenario related with shotcrete of railway tunnels wall surfaces, with the results showing the applicability of the developed work. The proposed procedure relies in highlighting the importance of specific points that describe the same feature in the reference and aligning PC. The proposed methodology achieved an RMS difference of 0.0173 m, which lead to a drastic improvement in the point cloud alignment compared to the use of standard ICP algorithm without data preprocessing, which achieved 0.0518 m in the studied use-case.
- Survey of SLAM Algorithms with ROS SupportPublication . Teixeira, Abel; Costelha, Hugo; Bento, Luis Conde; Neves, CarlosSimultaneous Localization and Mapping (SLAM) algorithms are a key component in enabling autonomous navigation for robotic systems. This study presents a comprehensive assessment of state-of-the-art SLAM algorithms, focusing exclusively on those with Robot Operating System (ROS) support. The study aims to provide insights into the computational performance of these algorithms by leveraging the benchmark results reported in their respective studies. Each algorithm's performance metrics, as reported in their benchmark studies, are analyzed and compared. This compara-ive analysis not only highlights the strengths and weaknesses of individual algorithms but also provides a broader understanding of their applicability across diverse robotic platforms and environments. Overall, this study contributes to the advancement of SLAM research by offering a comparative evaluation tailored to ROS-supported algorithms. The findings serve as a valuable resource to make informed decisions regarding the selection and implementation of SLAM solutions in real-world applications.
- Accuracy versus complexity of MARG-based filters for remote control pointing devicesPublication . Rasteiro, Miguel ; Costelha, Hugo; Conde Bento, Luis; Assunção, PedroAlthough most current pointing devices rely on relative rotation increments, absolute orientation allows for a more intuitive interaction. However, this is difficult to implement in low-energy consumption devices since accurate fusion filters are computationally intensive. This work presents a comparative study of low-complexity filters and state-of-the-art orientation tracking systems, enabling to access complexity versus portability. A relevant set of different MARG units currently available on the market were studied under systematic tests and human subjective user analysis. Experimental results show that it is possible to obtain similar accuracy using low-complexity filters to the ones observed with state-of-the-art orientation tracking systems. © 2015 IEEE.
- Collaborative Vehicle Self-Localization Using Multi-GNSS Receivers and V2V/V2I CommunicationsPublication . Conde Bento, Luis; Chelim, Rafael; Nunes, UrbanoThis paper presents a collaborative self-localization approach using a multi-GNSS receiver setup and V2V/V2I communications. The purpose is to develop a low-cost alternative (equipment and installation), without compromising the process of localization estimation. The proposed method uses two GPS-receivers installed on the vehicle, disposed longitudinally on the cover (to maximize the distance among receivers) in order to estimate the Yaw and Pitch angles. To estimate the Roll angle, the proposed approach uses information from a receiver on the road infrastructure or on a nearby vehicle using V2V and/or V2I communication (compliant with 802.11p standard). Experimental results revealed that the performance on both absolute positioning and Pitch angle estimation is very high. The method is accurate in Yaw angle estimation enabling acceptable results in heading computation. Therefore the use of this algorithm in risk assessment on crossroads approaching scenarios, is achievable with an affordable setup. The Roll angle estimation can reach satisfactory results if there is a third receiver in the vicinity and in a non-collinear position with respect to the installed onboard receivers.
- Inter-vehicle sensor fusion for accurate vehicle localization supported by V2V and V2I communicationsPublication . Conde Bento, Luis; Parafita, Ricardo; Nunes, UrbanoCooperative driving system techniques aim to minimize accidents, traffic congestion and consequently the environmental costs of road traffic. An accurate vehicle's pose is of extreme importance for the inner working of the traffic management systems. An agent based traffic simulator was developed integrating typical automotive sensors, vehicle-tovehicle (V2V) and vehicle-to-infrastructure (V2I) communications, vehicle's agent and infrastructure agent. In this paper, we propose to further enhance a multi-sensor localization algorithm in environments where V2V and V2I communication is possible. This paper describes an inter-vehicle sensor fusion for an accurate vehicle positioning, where each vehicle is modeled by an agent, and each agent provides information depending on its vehicle sensors. In the first fusion stage, data from four wheel encoders and one steering encoder are fused by means of an EKF, providing robust odometric information, namely in face of undesirable effects of wheels slippage. Next, a second fusion stage is processed for integrating odometric and inter-vehicle absolute positioning data.
- Intelligent traffic management at intersections supported by V2V and V2I communicationsPublication . Conde Bento, Luis; Parafita, Ricardo; Nunes, UrbanoThis paper describes an intelligent traffic management system applied to road intersections, namely round-about and crossroads. A microscopic traffic simulator was developed to study intelligent traffic management techniques and evaluate their performance. The intelligent management techniques are aimed to minimize accidents, traffic congestion and consequently the environmental costs of road traffic. Each vehicle is modeled by an agent and each agent provides information depending on its vehicle sensors. Two intersection types, roundabout and crossroads, were simulated each using its intelligent traffic management system. Both intersections use an algorithm based on a spatio-temporal reservation scheme. The envisioned intelligent traffic management algorithm is supported by vehicle-to-vehicle and vehicle-to-infrastructure communications, allowing the exchange of information between vehicles and the intersection intelligent traffic management system. The developed intelligent traffic management system is very well suited for autonomous vehicles, it can also be used by human drivers if they follow accurately the proposed speed profile along the path.