Robots' ability to perceive their physical environment is fundamentally tied to tactile sensing, as it faithfully captures the physical characteristics of contacted objects, ensuring stability against changes in lighting and color. Current tactile sensors, restricted in their sensing area and encountering resistance from their fixed surface during relative motion against the object, often require multiple, sequential probing actions—pressing, lifting, and relocating to other parts—to assess extensive target areas. The ineffectiveness and protracted nature of this process are undeniable. click here The deployment of these sensors is discouraged, as it frequently results in damage to the sensitive membrane of the sensor or the object being measured. To overcome these difficulties, we present the TouchRoller, an optical tactile sensor built upon a roller mechanism that spins about its center axis. The apparatus maintains a consistent connection with the assessed surface during the complete motion, facilitating a smooth and continuous measurement process. Comparative analysis of sensor performance showcased the TouchRoller sensor's superior capability to cover a 8 cm by 11 cm textured surface in just 10 seconds, effectively surpassing the comparatively slow 196 seconds required by a conventional flat optical tactile sensor. When the reconstructed texture map from the collected tactile images is compared to the visual texture, the average Structural Similarity Index (SSIM) registers a strong 0.31. The sensor's contacts are localized with a relatively small positional error, specifically 263 mm in central areas, and 766 mm in general. The high-resolution tactile sensing and effective collection of tactile images enabled by the proposed sensor will allow for a rapid assessment of expansive surfaces.
Utilizing the advantages of private LoRaWAN networks, users have successfully implemented diverse service types within the same LoRaWAN system, leading to various smart application developments. LoRaWAN struggles to accommodate numerous applications, causing issues with concurrent multi-service use. This is mainly attributed to limited channel resources, uncoordinated network settings, and problems with network scalability. Establishing a judicious resource allocation plan constitutes the most effective solution. Despite this, the existing solutions do not translate well to the multifaceted environment of LoRaWAN with multiple services, each demanding different criticality. Consequently, a priority-based resource allocation (PB-RA) method is proposed for coordinating multi-service networks. LoRaWAN application services are broadly categorized, in this paper, into three main areas: safety, control, and monitoring. The PB-RA scheme, taking into account the varying levels of importance in these services, assigns spreading factors (SFs) to end-user devices according to the highest priority parameter, ultimately decreasing the average packet loss rate (PLR) and increasing throughput. Moreover, a harmonization index, specifically HDex, based on the IEEE 2668 standard, is initially defined to evaluate the coordination ability in a comprehensive and quantitative manner, focusing on key quality of service (QoS) parameters like packet loss rate, latency, and throughput. Applying Genetic Algorithm (GA)-based optimization, the optimal service criticality parameters are determined to achieve a higher average HDex value for the network, alongside enhanced capacity for end devices, all the while upholding the HDex threshold for each service. Simulation and experimental data indicate that the PB-RA method effectively attains a HDex score of 3 for each service type on a network of 150 end devices, leading to a 50% improvement in capacity compared to the conventional adaptive data rate (ADR) scheme.
This article tackles the challenge of limited precision in dynamic GNSS measurements with a proposed solution. The method of measurement, which is being proposed, addresses the requirement to evaluate the measurement uncertainty associated with the track axis position of the rail line. However, the concern of reducing measurement error is prevalent in many situations that require high accuracy in the placement of objects, particularly when they are in motion. Using geometric limitations from a symmetrical deployment of multiple GNSS receivers, the article describes a new strategy to find the location of objects. A comparison of signals recorded by up to five GNSS receivers, both during stationary and dynamic measurements, served to confirm the proposed method. Within a cycle of studies dedicated to effective and efficient track cataloguing and diagnosis, a dynamic measurement was performed on a tram track. A scrutinizing analysis of the data acquired using the quasi-multiple measurement method highlights a substantial decrease in the level of uncertainty. Their synthesis underscores the usefulness of this method across varying conditions. The proposed methodology is anticipated to prove useful in high-accuracy measurements and in situations where the signal quality from satellites to one or more GNSS receivers deteriorates owing to natural obstructions.
In chemical processes, a wide array of unit operations commonly use packed columns. However, the speed at which gas and liquid travel through these columns is frequently restricted due to the risk of flooding. To guarantee the secure and productive operation of packed columns, timely flooding detection is indispensable. Real-time accuracy in flood monitoring is constrained by conventional methods' heavy reliance on manual visual inspections or inferential data from process variables. click here To effectively deal with this problem, a convolutional neural network (CNN) machine vision strategy was formulated for the non-destructive detection of flooding in packed columns. Real-time imagery, captured by a digital camera, of the column packed tightly, was analyzed with a Convolutional Neural Network (CNN) model pre-trained on an image database to identify flooding patterns in the recorded data. The proposed approach was scrutinized in relation to both deep belief networks and the integration of principal component analysis with support vector machines. Demonstrating the proposed method's potential and benefits, experiments were performed on a real packed column. The results establish the proposed method as a real-time pre-alarm system for flood detection, thereby facilitating swift response from process engineers to impending flooding events.
Intensive, hand-specific rehabilitation is now accessible in the home thanks to the development of the New Jersey Institute of Technology's Home Virtual Rehabilitation System (NJIT-HoVRS). We developed testing simulations, intending to give clinicians performing remote assessments more informative data. A study of reliability, contrasting in-person and remote testing, and evaluating the discriminatory and convergent validity of a six-part kinematic measurement battery, collected with the NJIT-HoVRS, is detailed in this paper. Two separate research experiments involved two distinct cohorts of individuals exhibiting chronic stroke-related upper extremity impairments. Using the Leap Motion Controller, every data collection session included six kinematic tests. Quantifiable data gathered includes the range of motion for hand opening, wrist extension, pronation-supination, along with the precision of hand opening, wrist extension, and pronation-supination. click here Using the System Usability Scale, the system's usability was evaluated during the reliability study by the therapists. Across the six measurements, a comparison of in-lab and initial remote data revealed that the intra-class correlation coefficients (ICC) were greater than 0.90 for three, and between 0.50 and 0.90 for the other three. Concerning the initial remote collection set, two ICCs from the first and second collections surpassed the 0900 mark, and the remaining four displayed ICC values between 0600 and 0900. These 95% confidence intervals, covering 95% of the ICC values, were broad, suggesting that subsequent studies with more participants are needed to affirm these initial findings. The SUS scores obtained from the therapists showed a spread between 70 and 90 points. The mean, 831 (SD = 64), is in accordance with the current state of industry adoption. Significant kinematic discrepancies were observed across all six measurements when contrasting unimpaired and impaired upper extremities. Five impaired hand kinematic scores out of six, and five impaired/unimpaired hand difference scores out of six, demonstrated correlations with UEFMA scores, falling within the 0.400 to 0.700 threshold. Regarding clinical practice, the reliability of all measurements was satisfactory. The results of discriminant and convergent validity studies point toward the scores from these tests having meaningful and valid implications. This process demands further testing in a remote context to ensure its validity.
To navigate a predetermined course and reach a set destination, airborne unmanned aerial vehicles (UAVs) depend on multiple sensors. To accomplish this goal, they frequently utilize an inertial measurement unit (IMU) to determine their orientation. Frequently, unmanned aerial vehicle systems utilize an inertial measurement unit, which is constituted by a three-axis accelerometer sensor and a three-axis gyroscope sensor. Yet, as is frequent with physical instruments, there can be an incongruity between the true value and the recorded data. Errors in measurements, either systematic or sporadic, might stem from issues within the sensor's design or from the environment where the sensor is situated. Calibration of hardware depends on particular equipment, which might not be available at all times. Despite this, should it be deployable, it could necessitate the sensor's removal from its current site, an operation not always readily available. Concurrently, the resolution of external noise issues typically involves software processes. Furthermore, the available literature shows that two IMUs of the same brand and production batch could produce different readings in identical conditions. Using a built-in grayscale or RGB camera on the drone, this paper introduces a soft calibration technique to address misalignment issues arising from systematic errors and noise.