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algorithms for Smooth, Safe and Quick Routing on Sensor-Equipped Grid Networks

SENSORS 2021年第24期21卷 8188-8188页

作者： Andreatta, Giovanni De Francesco, Carla De Giovanni, Luigi Univ Padua Dipartimento Matemat Tullio Levi Civita I-35122 Padua Italy

Automation plays an important role in modern transportation and handling systems, e.g., to control the routes of aircraft and ground service equipment in airport aprons, automated guided vehicles in port terminals or in public transportation, handling robots in automated factories, drones in warehouse picking operations, etc. Information technology provides hardware and software (e.g., collision detection sensors, routing and collision avoidance logic) that contribute to safe and efficient operations, with relevant social benefits in terms of improved system performance and reduced accident rates. In this context, we address the design of efficient collision-free routes in a minimum-size routing network. We consider a grid and a set of vehicles, each moving from the bottom of the origin column to the top of the destination column. Smooth nonstop paths are required, without collisions nor deviations from shortest paths, and we investigate the minimum number of horizontal lanes allowing for such routing. The problem is known as fleet quickest routing problem on grids. We propose a mathematical formulation solved, for small instances, through standard solvers. For larger instances, we devise heuristics that, based on known combinatorial properties, define priorities, and design collision-free routes. Experiments on random instances show that our algorithms are able to quickly provide good quality solutions.

关键词： automated transportation network collision-free routing grid network optimization algorithm integer linear programming heuristics

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Modeling and optimizing in vitro seed germination of industrial hemp (Cannabis sativa L.)

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INDUSTRIAL CROPS AND PRODUCTS 2021年 170卷 113753-113753页

作者： Hesami, Mohsen Pepe, Marco Monthony, Adrian Scott Baiton, Austin Jones, Andrew Maxwell Phineas Univ Guelph Dept Plant Agr Guelph ON N1G 2W1 Canada

In vitro seed germination of cannabis as the first physiological stage in the plant life cycle is not only important for studying factors affecting cultivation conditions but also crucial for obtaining juvenile tissue as a potential explant for different in vitro procedures. On the other hand, in vitro seed germination is a multi-variable biological process that can be influenced by genetic (genotype) and physical factors (medium composition and environ-mental conditions). Therefore, a powerful mathematical methodology such as artificial neural networks (ANNs) is well suited to analyze the data and optimize the conditions this complex system. The current study was aimed to evaluate the effect of different types and concentrations of carbohydrate sources (sucrose and glucose) as well as different strengths of DKW (Driver and Kuniyaki Walnut) and mMS (Murashige and Skoog Medium, Van der Salm modification) media on seed germination indices as well as morphological features of in vitro-grown cannabis seedlings by using three ANNs including multilayer perceptron (MLP), radial basis function (RBF), and generalized regression neural network (GRNN). The GRNN model displayed higher predictive accuracy (r(2)>0.70) in both training and testing sets for all germination indices and morphological traits in comparison to RBF or MLP. Moreover, non-dominated sorting genetic algorithm-II (NSGA-II) was subjected to the GRNN to find the optimal type and level of media and carbohydrate source for obtaining the best seed germination indices (germination rate and mean germination time). According to the optimization process, 0.43 strength mMS medium supplemented with 2.3 % sucrose would result in the best outcomes. This result showed that a moderate level of salts existing in culture media (0.43 strength of mMS medium) supplemented with a moderate level of sucrose (2.3 %) can improve in vitro seed germination of hemp. The results of a validation experiment revealed that there was a neglig

关键词： Artificial intelligence Carbohydrate sources Culture medium Machine learning algorithm optimization algorithm Plant tissue culture

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Explanation Approaches for the Daphne Virtual Assistant

Explanation Approaches for the Daphne Virtual Assistant

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AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Viros, Antoni Selva, Daniel Texas A&M Univ Aerosp Engn College Stn TX 77843 USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

Explainability of Artificial Intelligence (AI) agents has become a major concern. This paper describes the different approaches to explaining decisions that are used in Daphne, a Virtual Assistant to support the early design of Earth observing systems. Feedback from past studies with expert systems engineers emphasized the importance of providing rich and transparent explanations. This paper explains how state-of-the-art techniques for AI explainability can be applied to a design tool that uses many different AI techniques. These improvements have been implemented in all Daphne roles, as well as the Question Answering (QA) system. The approaches include a revamped dialogue system, using an additive feature explanation method to explain how a neural network decides what the intent of a question is, leveraging the transparency of rule-based systems to come up with explanations in text and graphical formats, and explaining how data mining algorithms for design feature extraction and database summarizing work to end users through user-friendly text messages.

关键词： Generative Adversarial Network Data Mining algorithms Systems Engineering Artificial Intelligence Concurrent Engineering Machine Learning Black Box Earth optimization algorithm Sensitivity Analysis

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Turbulence Profiling Using AAOL-BC

Turbulence Profiling Using AAOL-BC

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AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Kalensky, Matthew Diskin, Yakov Whiteley, Matthew R. Jumper, Eric J. Drye, Richard Grose, Mitchell Jackovitz, Kevin Hampshire, Brandon Smith, Eric Archibald, Aaron Gordeyev, Stanislav Zenk, Mike Univ Notre Dame Dept Aerosp & Mech Engn Notre Dame IN 46556 USA MZA Associates Corp 1360 Technol CtSuite 200 Dayton OH 45430 USA US Air Force Inst Technol Dept Aerosp & Mech Engn 2950 Hobson Way Wright Patterson AFB OH 45433 USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

AAOL-BC was employed to conduct experiments that seek to measure path resolved turbulence quantities. To explore the impact that atmospheric turbulence has on optical systems, a Path Resolved Optical Profiler System (PROPS) was employed. Ground-based and in-flight studies are conducted simultaneously and C-n(2) profiles are computed allowing the relationship between atmospheric turbulence strength and propagation path to be analyzed.

关键词： Atmospheric Turbulence Ground Station Telescopes Mach Numbers Refractive Index Data Acquisition Track algorithm Turbulence Models optimization algorithm Optical Communication

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A probabilistic path planning framework for optimizing feasible trajectories of autonomous search vehicles leveraging the projected-search reduced Hessian (LRH-B) method

A probabilistic path planning framework for optimizing feasi...

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AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Subramanian, Abhishek Alimo, Ryan Gill, Philip E. Bewley, Thomas R. UCSD Dept MAE La Jolla CA 92093 USA CALTECH Jet Prop Lab La Jolla CA USA UCSD Dept Math La Jolla CA USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

This paper presents a new probabilistic algorithm for trajectory planning for autonomous vehicles (AV) in search and security applications. The goal is to compute optimized paths for the AVs in real time which maximize the probability of locating a fixed target, subject to constraints on the vehicle dynamics, within a prespecified time horizon. The likelihood of not detecting the target is modeled in a probabilistic manner based on approximate models of sensor acuity as a function of the distance to (and, the speed of) the sensor vehicle. For any possible vehicle path, a cost function is considered that accumulates the overall likelihood of not locating the target. Using an adjoint-based calculation, the gradient of this cost with respect to the control inputs is determined. The formulation of the cost function and the vehicle dynamics are decoupled, facilitating easy extension of the framework developed to other types of vehicles. The framework can also account for a priori estimates of the probability distribution of the target of interest. To accelerate convergence, we use the projected-search limited-memory reduced Hessian (LRH-B), a recently developed gradient-based optimization method for constrained optimization;the LRH-B method significantly outperforms existinga* optimization algorithms as implemented in standard packages. Results indicate that our new framework can efficiently coordinate the search over the domain, and that LRH-B reduces the total computational cost during the search.

关键词： Motion Planning Probability Distribution optimization algorithm Sensors Robots Newton's Method Model Predictive Control Augmented Lagrangian Method Search algorithm Computing

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Simultaneous Learning optimization of Hamiltonian Systems and Trajectory Tracking Around an Asteroid

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2020年第2期43卷 222-231页

作者： Taniguchi, Asuto Satoh, Satoshi Yamada, Katsuhiko Osaka Univ Suita Osaka 5650871 Japan Osaka Univ Grad Sch Engn Suita Osaka 5650871 Japan Ricoh Co Ltd Ota Tokyo Japan

This paper proposes a simultaneous learning optimization method of feedforward input and adjustable parameters using variational symmetry, which is a special property of Hamiltonian systems. First, a new input/output mapping of Hamiltonian representation is constructed, in which feedforward control input and a finite number of adjustable parameters are defined as the input to the system. Then, a modified variational symmetry for the present Hamiltonian system is derived by introducing two operators. Thanks to the modified variational symmetry, the present learning algorithm simultaneously calculates the gradient of a given cost function with respect to an arbitrary number of feedforward inputs and parameters included in the Hamiltonian with at most two gradient experiments without using the plant system model. Furthermore, the proposed method is applied to trajectory tracking control of a spacecraft near an asteroid. Here, the feedback gains of a local proportional derivative feedback controller to stabilize the system and feedforward control input to improve tracking performance are simultaneously optimized by learning. The present numerical simulations verify that the cost function decreases to a local minimum, the maximum tracking error significantly decreases, and the obtained optimal feedforward input behaves closely to the analytically calculated input for perfect tracking.

关键词： Asteroids Iterative Learning Control Numerical Simulation Optimal Control optimization algorithm Gradient Method Feedback Control Celestial Mechanics Solar Radiation Hilbert Space

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optimization algorithms for ultrasonic array imaging in homogeneous anisotropic steel components with unknown properties

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NDT & E INTERNATIONAL 2020年 116卷 102327-102327页

作者： Menard, Corentin Robert, Sebastien Miorelli, Roberto Lesselier, Dominique CEA LIST Dept Imaging & Simulat Nondestruct Testing Bat 565Pc 120 F-91191 Gif Sur Yvette France Univ Paris Saclay Lab Signaux & Syst Cent Supelec CNRS F-91190 Gif Sur Yvette France

In this paper, we investigate the ability of an adaptive ultrasonic method to image point-like reflectors inside anisotropic and homogeneous nuclear steels with unknown properties, such as V-shape welds or cladded components. The optimization scheme combines the Total Focusing Method (TFM) imaging algorithm with a customized gradient ascent method to improve both the quality and the reliability of ultrasound images. A statistical analysis of its robustness is performed with simulated echoes and using a surrogate model to speed up the computation times of the TFM images. Then, the optimization procedure is evaluated with several experimental cases and provides highly enhanced images with a 5 MHz array. The positioning of the artificial defects of 2.0 mm diameter is estimated with less than 1 mm error with respect to their actual position, and the signal-to-noise ratio is increased by up to 10 dB. The elastic properties are also estimated with less than 10% error when compared to their actual values.

关键词： Ultrasonic array Total Focusing Method Adaptive imaging Anisotropic materials optimization algorithm Surrogate-model

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Flutter Prediction Using Reduced-Order Modeling

Flutter Prediction Using Reduced-Order Modeling

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AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Lowe, Brandon M. Zingg, David W. Univ Toronto Inst Aerosp Studies 4925 Dufferin St Toronto ON M3H 5T6 Canada

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

Typical aerodynamic shape and multidisciplinarya* optimization algorithms omit high-fidelity flutter predictions due to the associated computational costs. This paper presents a model order reduction framework as a step towards flutter constrained aircraft optimization. The Euler equations linearized about a steady-state solution are used as the governing unsteady flow equations. Using proper orthogonal decomposition, a reduced basis is constructed onto which the governing equations are projected. The result is a linear reduced-order model (ROM) with significantly fewer degrees of freedom capable of rapidly approximating aerodynamic forces. This ROM is coupled to a linear structural model to create a single monolithic aeroelastic system. The eigenvalues of the resulting system are analyzed for various flow conditions to determine the onset of flutter in the system. The flutter boundaries obtained for both a two degree of freedom airfoil structure and the AGARD 445.6 wing model show good agreement with the full-order model and with the literature.

关键词： Euler Equations Aerodynamic Shape optimization Structural Modeling Transonic Pitching Airfoil Implicit Euler Method Dynamic Aeroelastic Analysis Unsteady Transonic Flow optimization algorithm Reynolds Averaged Navier Stokes Angle of Attack

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Enhancing Designer Understanding by Combining Multiple Dominance Relations and Tabu Search

Enhancing Designer Understanding by Combining Multiple Domin...

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AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Phillips, Samuel T. Jarrett, Jerome P. Univ Cambridge Dept Engn Cambridge CB2 1PZ England

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

In this paper a new tabu search (TS) implementation of the optimization using multiple dominance relations (MDR) approach is presented. Unlike previous population-based implementations, this new algorithm is able to provide the user with information regarding the development history of the final designs produced. This helps the designer gain physical insights into how the observed performance improvements have been achieved by the optimizer. The ability to provide the physical reasoning behind predicted performance improvements is essential if optimized designs are to be adopted in industry, particularly when safety is critical. The new algorithm is shown to outperform previous implementations when applied to both analytic and airfoil design test cases, with the tracking of design development illustrated using the latter problem. The additional information provided to the user comes at no additional computational cost, increasing the value of each optimization run. The more robust design space searching capabilities of the TS upon which the new implementation is built also facilitates the application of the MDR approach to a new class of more complex design problems.

关键词： Airfoil Robust Design Drag Coefficient Particle Swarm optimization Lift Coefficient optimization algorithm Multi Objective Genetic algorithm Computational Fluid Dynamics Unmanned Aerial Vehicle Search algorithm

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Aerodynamic Optimal Design of Guided Bullets Based on Improved Orthogonal Test 3

Aerodynamic Optimal Design of Guided Bullets Based on Improv...

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3rd International Conference on Unmanned Systems (ICUS)

作者： Ma, Nuo Li, Moning Li, Xiaozhu Meng, Junhui Liu, Li Beijing Inst Technol Sch Aerosp Engn Beijing Peoples R China Xian Inst Modern Control Technol Xian Peoples R China

ISBN: (纸本)9781728180250

With the development and miniaturization of guidance technology, guided bullets have revolutionaryly improved the accuracy and survivability of sniper. Different from the designing of traditional bullets that focus on minimizing drag, the guidance raises the requirement of high lift-drag ratio of guided bullets during maneuvering to ensure the efficiency of maneuver and the ability of storing energy. In this paper, based on the improved orthogonal test optimization, the boundary between each segment of the projectile is selected as the control factors, and lift-drag ratio under the maximum rudder deflection is set as the objective factor to optimize aerodynamic shape of the guided bullet. In terms of conclusion, the maximum lift-drag ratio is increased by about 80%, which shows that the optimization has significant effect. The proposed new method improves the searching ability while taking the processing capacity of the control factors and computational cost of orthogonal test into account. It has certain significance for the solution of low-dimensional unconstrained optimization problems and provides a reference for the design of guided bullets.

关键词： guided bullet,improved orthogonal test optimization optimization algorithm aerodynamic optimal design

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