bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Integrated Task and Path Planning Approach for Mobile Robots in Smart Factory
Authors: Liu Shuo , Feng Bohan , Yu Dan , Bi Youyi 
Published: February 2023

Abstract
Mobile robots are being widely used in smart manufacturing, and efficient task assignment and path planning for these robots is an area of high interest. In previous studies, task assignment and path planning are usually solved as separate problems, which can result in optimal solutions in their respective fields, but not necessarily optimal as an integrated problem. Meanwhile, precedence constraints exist between sequential processing operations and material delivery tasks in the manufacturing environment. Thus, those planning methods developed for warehousing and logistics may not simply apply to the environment of smart factories. In this paper, we propose an integrated task and path planning approach based on Looking-backward Search Strategy (LSS) and Regret-based Search Strategy (RSS). In the stage of task assignment, the real paths for mobile robots are identified based on the Cooperative A* (CA*) algorithm and the time and energy consumed by mobile robots and machining centers are calculated. Then a greedy strategy working with LSS or RSS is used to search reasonable task assignments in time-series, which can generate a joint optimal solution for both task assignment and path planning. We verify the validity of the proposed approach in a simulated smart factory and the results show that our approach can improve the operation efficiency of the smart factory and save the time and energy consumption effectively.
Experimental Study of a Novel 4 Stroke Spark Ignition Geared-Hypocycloid Engine
Authors: Nunes Alexandre , Brojo Francisco 
Published: February 2023

Abstract
The aim of this work was to develop a geared-hypocycloid engine to be able to determine its feasibility and performance characteristics. This was done by modifying an existing engine with a custom-designed geared mechanism to replace the conventional slider-crank mechanism (crankshaft).
The geared-hypocycloid engine design takes advantage of the hypocycloid concept, more specifically when the diameter of the inner circle is equal to the radius of the outer circle. In this specific case, the piston moves only in the longitudinal direction along the cylinder, and in a true sinusoidal motion. This motion results in reduced mechanical losses by friction of the piston head against the cylinder due to very little side forces action on the piston, as well as the piston remaining near the top-dead center, and thus in higher in-cylinder pressure, for a longer period of time. Consequently, higher torque and power output can be achieved with no increase in fuel consumption, resulting in higher efficiency. Vibrations were found to be considerably low but the geared mechanism showed high noise during operation.
The engine performance parameters such as the rotational speed, torque output and fuel consumption were measured on a dynamometer. This data allowed for power, specific fuel consumption and overall efficiency to be calculated.
Hybrid-Electric Propulsion Solutions for UAV Application
Authors: Marto Diogo , Brójo Francisco 
Published: February 2023

Abstract
Due to the rapid growth of the aviation industry, the concentrations of hazardous pollutants in the atmosphere are rising and the need for more environment-friendly solutions is higher than ever. This study aims to test and show the benefits of hybrid-electric propulsion systems in UAVs in two possible configurations, parallel and series. The hybrid propulsion system combines a 28-cc 2-stroke internal combustion engine with a 200-watt frameless generator. As a primary approach, the engine alone with a 16-inch diameter and 12-inch pitch propeller is characterized by its torque, power and specific fuel consumption throughout the engine’s operating range. In a second approach, the hybrid component is added and a comparison between both results taken is made. Preliminary results show that parallel configuration offers lower specific fuel consumption in comparison with the engine alone. Also, the higher load on the engine used as the primary powerplant seems to promote a more stable operation, with higher throttle control and lower vibrations. In a final remark, considerations regarding the two configurations are made. These considerations aim to establish the best points to operate each architecture and which one is best suited to be implemented on a UAV depending on the mission profile.
Study of the Influence of Different Geometries of an Organ-on-a-Chip
Authors: Carvalho Violeta , Rodrigues Nelson , Rodrigues Raquel O. , Teixeira José C. , Miranda João , Lima Rui A. , Teixeira Senhorinha 
Published: February 2023

Abstract
Organs-on-a-chip, OoC, have been extremely important to reduce the use of animal models allowing researchers to conduct accurate in vitro experiments with high throughput. Year after year, increasingly complex OoC platforms have been developed to better recapitulate the in vivo environment, and numerical simulations have played a fundamental role in this process. Numerical simulations in health sciences research are constantly evolving and have allowed researchers not only to better understand but also to complement and improve the in vitro experiments.
Aiming to evaluate the influence of geometry on fluid flow, in the present work, three different geometries of a single organ-on-a-chip were created, and numerical simulations were conducted by using Ansys® Fluent software. The fluid flow of the culture medium with dissolved oxygen was simulated. In terms of oxygen consumption, the influence of the geometry was noticeable in the organoid region. In terms of velocity fields, the results were not significantly affected by the geometry.
Outdoor System for Synchronous Triggering of Multiple Scientific Cameras Using Direct-Access GNSS Time Transfer
Authors: Bjelotomic Marko , Subramaniam Prashanth , Rashid Lapuz Oginne , Almaeeni Khuloud , Anzil Mohammed Minhas , Bendoukha Sidi Ahmed , Pomares Luis 
Published: February 2023

Abstract
Atmospheric measurement techniques often require synchronous data capturing throughout the day, at the exact moment, more than capturing it at preset points in time. The system utilizes time stamps sent from the atomic clocks on navigation satellites. Time stamps received from the satellites by the GNSS receiver are turned into a triggering impulse. Impulses are needed for triggering the repurposed low-noise scientific cameras. The cameras must be mobile in an outdoor setup with a synchronized triggering system. However, the system is not limited to low-noise scientific cameras; it can be fitted to suit other applications requiring synchronous impulse, with a timestamping option. Systems comprise a microcontroller paired with a GNSS receiver which has access to the constant, one pulse per second, stream of GNSS satellite emitted time impulses. The GNSS receiver is connected to the camera and the microcontroller unit (MCU). 1PPS pin on the GNSS module is connected to a camera acting as its external trigger. The microcontroller is connected to the GNSS module accepting the NMEA sentences. Further, MCU communicates via USB with a data storage device, providing formatted time tagging data. The satellite impulse is directly converted to the camera trigger signal, allowing an indefinite number of devices to be triggered within a 30 nanosecond gap, with the possibility of triggering multiple low-noise cameras and other trigger-needing sensors distributed hundreds of meters or kilometers apart. The microprocessor generates the time tag without influencing the moment of the time of the trigger. GNSS module independently gives synchronous triggers while parallelly sending the data to the MCU to process it before the next satellite signal, which comes every second. We evaluate the solution on three commonly available prototyping boards in search of the least time difference between their trigger pulses.
Excel® VBA for Thermal Science Applications
Authors: Jones J. H. , Eldredge T. V. 
Published: February 2023

Abstract
Thermal science classes require the use of a number of components to the governing equations that require the use of tables and figures in order to generate solutions to assigned problems. Examples of some of these components are thermal properties, empirical correlation results, correction factors from various textbook figures, viewfactors for thermal radiation, complicated empirical correlations, etc. The application of some of these components can be time consuming and error prone. A series of EXCEL® Visual Basic for Applications (VBA) functions were created or adapted from various internet sources to streamline thermal science analyses and allow the learners to spend more time evaluating solution behavior/sensitivity as opposed to generating results. These VBA functions have application in fluid dynamics, heat transfer, and thermodynamics courses and allow the learners to focus on understanding the concepts without the need to perform various tedious tasks.
Direct-on-Chip Microscale Jet Array Impingement Cooling With Trapezoid Diversion Columns
Authors: Yang Jingshan , Cheng Keyong , Huai Xiulan 
Published: February 2023

Abstract
Microscale jet array impingement cooling has been proved to be an efficient cooling technique for high-heat-flux electronics. In order to meet the current development trend of electronic components, jet impingement cooling performance needs to be continuously improved. In this work, a target surface enhancement approach for direct-on-chip microscale jet array with alternating feeding and draining jets was proposed. Trapezoid diversion columns were set regularly around inlet jets on the target surface to guide spent fluid and enhance overall performance. Besides, the inlet Reynolds number ranged from 20 to 2000 and deionized water was used as the coolant. Firstly, the impact of trapezoid diversion columns on flow and heat transfer characteristics was studied by numerical method. The results showed that the Nusselt number of current jet array was enhanced remarkably than that of convectional jet array at the almost same cost of pressure loss. Then the optimization of columns height, shape and location were carried out to improve overall performance. As a result, an optimal jet array structure with best overall performance was proposed. In the end, the maximum thermal removal capacity of optimal jet array and basic jet array was compared. It was found that the proposed optimal jet array can remove heat flux of 1950 W/cm2 when the temperature rise of heated surface was below 85 °C, which was 28.3% higher than that of basic jet array.
Adaptive Assist As Needed Control Strategy for a Lower Limb Exoskeleton
Authors: Kumbhar Shubham Shrikant , Sangwan Vivek 
Published: February 2023

Abstract
Robotic Exoskeletons for legs are able to act as excellent evaluation as well as training devices while reducing physical effort that a therapist needs to expend. For such exoskeletons, assist as needed control strategies are advantageous because these lead to active participation from the user. One such strategy is based on Force Fields where the controller creates a virtual force field around the foot of the user to aid the user’s leg motion. Force field controllers (FFC) presented in literature require the knowledge of parameters such as length, mass, position of center-of-mass and moment of inertia for the combined human-exoskeleton system. This paper presents an “adaptive” assist as needed control strategy that creates a virtual force field similar to the FFC without using any prior knowledge of human inertial parameters like mass, the moment of inertia, the position of COM, etc. A lyapunov stability proof for the proposed controller is also presented along with simulation results demonstrating the controller.
Automated Generation of Hybrid Probabilistic Risk Models From SysML V2 Models of Software-Defined Manufacturing Systems
Authors: Grimmeisen Philipp , Ma Yuliang , Diaconeasa Mihai A. , Morozov Andrey 
Published: February 2023

Abstract
The concepts of Software-Defined Manufacturing (SDM) and Digital Twins emphasize the current trend in production system development. These systems are characterized by frequent software updates to address adjustable production processes and higher system flexibility. These software-intensive systems are safety-critical and require a thorough reliability analysis. This implies the necessity to automatically re-evaluate the reliability before each software update.
In this paper, we introduce a new Model-to-Model (M2M) transformation method that enables the automatic generation of hybrid reliability models from the Digital Twin formalism based on SysML v2. The models of the Digital Twin are extended with reliability data. The method includes (i) transformation of behavioral models to Markov chains, (ii) transformation of structural models to fault trees, and (iii) the generation of hybrid reliability models based on the software and system structure. Besides, this paper describes an SDM-system, based on a robotic manipulator, that fulfills two different tasks depending on the uploaded software. This case study shows that our M2M transformation method enables continuous reliability assessment of SDM-systems.
Designing a Physical Model for the Emsworth Lock and Dam Filling and Emptying System
Authors: Doshi Nathan , Hancox Jacob , Karkhai Polakrit , Smith Cameryn , Tawakkol Adam , White Spencer , Bristow Elizabeth , Hill Aaron , McCoy Brad , Nowicki Margaret 
Published: February 2023

Abstract
Currently, the system of locks and dams within the United States operate where each system has a different component and needs different parts to complete the routine maintenance checks and procedures. Having unique components and parts for each lock and dam system drastically increases the costs required for the United States Army Corps of Engineers (USACE) to operate and maintain these locks and dams. One way to reduce these costs is to work towards and recommend standardized components for a lock and dam system. This process, especially for construction projects, is vital because it allows for simplification in the build and production stages of a project as well as life cycle maintenance.
Understanding hydraulic design for the inflow and outflow of a lock system was an important consideration for this design project. Reducing hawser forces while maximizing the efficiency of the filling and emptying process is the overall goal for the design. To minimize hawser forces, mitigating the effects of hydrodynamic and hydrostatic forces is essential. This research also strives to gain additional understanding of the dynamic, turbulent nature of water in a lock and dam system. In the Emsworth Lock and Dam system, the top of rock for the riverbed is significantly higher than normal presenting unique challenges for modeling and simulation, as well as physical model construction. Critical to the design of a physical model is the determination of an adequate scaling factor that will not significantly affect the natural hydraulic processes within the system. As such, it is essential that appropriate theories are applied to remain consistent with proven methods of hydraulic scaling.
Before selecting a scaling ratio, determining space limitations and a conceptual design of the model was necessary. This assisted in visualizing the model in the available spaces to ensure the design and manufacturing plan was realistic. The model contains three components: a main lock chamber, a higher elevation water reservoir, and a lower elevation water reservoir. The component that is most controlling to the design is the main lock chamber; this component cannot be altered in any way to meet the requirements of the floor space because any modifications would affect the results of the hawser force testing, and the model would not appropriately match reality. The physical model will be verified using the Froude equation — an equation that drives performance of models that are dependent on gravity. As such, when conducting any inflow or outflow of the water in the system, it is essential that the velocity is controlled such that the Froude value is consistent with that of the actual Emsworth Lock and Dam. The model must match a Froude number of 0.052 to effectively represent reality.
Economic Viability vs. Risk Mitigation: An Experimental Investigation of Project Budget Investment Decisions in Engineering Students
Authors: Midlick Mark J. , Gernand Jeremy M. 
Published: February 2023

Abstract
In the course of their profession, engineers must often consider not just the technical efficacy of their designs but also how their design decisions influence and are influenced by nontechnical factors. These non-technical factors can include the stated or implicit values of a company culture, the real and/or perceived social pressures from management, and individual perceptions about one’s own ethical and professional duties and responsibilities. In the field of Psychology there is a large body of research relating the internal, mental states of individuals to their external behaviors and choices. However, at this time there has been little research into how different psychological states can affect the outcome of specific engineering design decision making by individuals or teams. This study’s aim was to begin this research by conducting an experiment to simulate a common constraint in the profession of engineering: allocating a design budget to ensure the project outcome is both profitable and safe. Specifically, this study wanted to measure how the personality trait agreeableness in conjunction with a social primer consisting of a written scenario description conveying the aims of the exercise and the responsibilities of engineers related to an engineering student’s decision to favor either profit or safety in a hypothetical design scenario. A total of 141 undergraduate engineering students were recruited to participate in this experiment, which consisted of a computer-based survey and decision-making activity with a total duration of approximately 10 minutes. Results indicated that agreeableness did not relate to primer adherence in a statistically significant way; however participant beliefs about the intention of the experiment did have a statistically significant relationship with their final allocation decisions, a finding that may have implications for the management of engineering design teams, if this research can be replicated in experienced professionally practicing engineers. While not the objective of the experiment, the data show that when participants were given the opportunity to revise their selections, they most commonly revised their allocations away from profit and towards more investment in safety. Whether this is a result of simply a second attempt at the same decision with further reflection or the result of the consideration of information considered after the initial allocation remains to be determined in future research. The results of this study should serve not as conclusive evidence on the effects of trait agreeableness in engineering risk-related decision making but rather as an initial step, or model for how to investigate a potentially valuable, interdisciplinary field of inquiry. Insights from this experiment do hold useful lessons for the next phase of this research.
Autonomous Topographic Mapping of Unknown Environments by Dynamic Visual Data
Authors: Raju Vomsheendhur , Selekwa Majura F. 
Published: February 2023

Abstract
The simultaneous localization and mapping (SLAM) process is what makes it possible for autonomous vehicles to navigate in unknown environments. Early SLAM algorithms used and relied on ranging sensors only. In recent years, there has been an increased interest in vision-based SLAM (V-SLAM) due to the low-cost nature of digital cameras available in the market compared to ranging sensors. V-SLAM uses successive camera frames to either track features in individual frames and triangulates the position to construct a 3-D map or determine the vehicle speed by measuring the rate of change of these features relative to a known reference. This paper proposes an effective real-time method of creating a topological 3D map of the environment from a stereo vision system by using an improved stereo correspondence algorithm that minimizes errors caused by illumination and texture variation in the disparity map generation. The Cartesian world coordinates corresponding to each pixel are computed from the disparity map generated by triangulating the depth of the pixels in the reference perspective projection image to create a 3-D map of the scene as a point cloud plot. Analysis of the resulting point cloud plot indicates that the coordinates of each pixel provide the 3-D information about the scene representing a working topological map that can be used to detect the obstacles in close vicinity to the robot.
Exit Time Differences Between Gated and Open Operator Compartments in Stand-Up End-Controlled Lift Trucks With an Examination of Injury Potential in Tip-Over and Off-Dock Incidents
Authors: Martinez Jonathan , Germane Alex , Watson Richard , Gwin Lisa 
Published: February 2023

Abstract
Stand-up end-controlled forklifts typically have two different mechanisms for injury to the operator; injury to a limb extended outside the operator compartment or injury incurred in off-dock and tip-over type accidents. Lift truck operator compartments are designed with an open portal in compliance with current lift truck safety standards which instruct operators to egress the vehicle in the event of an off-dock or tip-over. It has been suggested that a door over the portal may be beneficial by preventing the operator from extending limbs outside the vehicle. Conversely, a door may add critical time to egress in the emergency of an off-dock or tip-over accident.
This study examined the time needed for egress with and without a door using 38 trained operators. Operators were tested in an experimental process including 151 tests with a door and 152 tests without a door. There was a statistically significant increase in the amount of time needed for egress with a door present versus without a door.
The potential for injury to an occupant that is not able to exit the cabin in off-dock and tip-over scenarios was tested using a Hybrid III 50th percentile male ATD to measure injury metrics. One tip-over and seven off-dock tests were conducted. Seven of the eight test situations resulted in serious or life-threatening injury measurements to the ATD.
Benchmarking Various Nonlinear Control Design Techniques for a Two-Link Planar Robot Arm
Authors: Ilhan Zeki 
Published: February 2023

Abstract
This work aims to demonstrate and benchmark different model-based nonlinear control design techniques for elementary controls education. A standard, two-link planar robot arm (Fig.1) is chosen to be the plant due to its nonlinear system dynamics and relatively simple inverse kinematics considering the math level of complexity of a typical senior-level mechanical engineering class. To facilitate model-based control design, the system dynamic model is derived through Lagrange’s equations in non-conservative form. An inverse kinematic analysis is also performed to extract the target joint variables to match for a circular motion executed in the task space. Finally, the system dynamic model is incorporated with feedback control designs based on the computed torque and sliding mode control methods. The tracking performance of the proposed nonlinear controllers are validated in closed-loop numerical simulations based on the same target trajectories to compare the performances achieved by the different algorithms.