Unmanned Syst.最新文献_第9页

Neural Decision Tree Towards Fully Functional Neural Graph 面向全功能神经图的神经决策树

Unmanned Syst. Pub Date : 2020-02-03 DOI: 10.1142/s2301385020500132

Han Xiao, Ge Xu

引用次数: 0

Distributed Drone Traffic Coordination Using Triggered Communication 使用触发通信的分布式无人机交通协调

Unmanned Syst. Pub Date : 2020-01-08 DOI: 10.1142/S2301385020500016

Abdul Hanif Bin Zaini, Lihua Xie

引用次数: 11

Optimally Allocated Nonlinear Robust Control of a Reusable Launch Vehicle During Re-entry 可重复使用运载火箭再入过程最优分配非线性鲁棒控制

Unmanned Syst. Pub Date : 2020-01-08 DOI: 10.1142/S230138502050003X

S. Mathavaraj, R. Padhi

引用次数: 4

Feasibility Study of a Multi-Purpose Aircraft Concept with a Leading-Edge Embedded Cross-Flow Fan 前沿嵌入式横流风扇多用途飞机概念的可行性研究

Unmanned Syst. Pub Date : 2020-01-08 DOI: 10.1142/S2301385020500028

S. Karpuk, Snorri Gudmundsson, V. Golubev

引用次数: 1

Machine Learning-Based Crop Drought Mapping System by UAV Remote Sensing RGB Imagery 基于机器学习的无人机RGB遥感作物干旱制图系统

Unmanned Syst. Pub Date : 2020-01-08 DOI: 10.1142/s2301385020500053

Jinya Su, M. Coombes, Cunjia Liu, Yongchao Zhu, Xingyang Song, S. Fang, Lei Guo, Wen‐Hua Chen

{"title":"Machine Learning-Based Crop Drought Mapping System by UAV Remote Sensing RGB Imagery","authors":"Jinya Su, M. Coombes, Cunjia Liu, Yongchao Zhu, Xingyang Song, S. Fang, Lei Guo, Wen‐Hua Chen","doi":"10.1142/s2301385020500053","DOIUrl":"https://doi.org/10.1142/s2301385020500053","url":null,"abstract":"Water stress has adverse effects on crop growth and yield, where its monitoring plays a vital role in precision crop management.\u0000This paper aims at initially exploiting the potentials of UAV aerial RGB image in crop water stress assessment by developing a\u0000simple but effective supervised learning system. Various techniques are seamlessly integrated into the system including vegetation\u0000segmentation, feature engineering, Bayesian optimization and Support Vector Machine (SVM) classifier. In particular, wheat pixels\u0000are first segmented from soil background by using the classical vegetation index thresholding. Rather than performing pixel-wise\u0000classification, pixel squares of appropriate dimension are defined as samples, from which various features for pure vegetation pixels\u0000are extracted including spectral and colour index features. SVM with Bayesian optimization is adopted as the classifier. To validate\u0000the developed system, a UAV survey is performed to collect high-resolution atop canopy RGB imageries by using DJI S1000 for\u0000the experimental wheat fields of Gucheng town, Heibei Province, China. Two levels of soil moisture were designed after seedling\u0000establishment for wheat plots by using intelligent irrigation and rain shelter, where field measurements were to obtain ground soil\u0000water ratio for each wheat plot. Comparative experiments by three-fold cross-validation demonstrate that pixel-wise classification,\u0000with a high computation load, can only achieve an accuracy of 82.8% with poor F1 score of 71.7%; however, the developed system\u0000can achieve an accuracy of 89.9% with F1 score of 87.7% by using only spectral intensities, and the accuracy can be further\u0000improved to 92.8% with F1 score of 91.5% by fusing both spectral intensities and colour index features. Future work is focused on\u0000incorporating more spectral information and advanced feature extraction algorithms to further improve the performance.","PeriodicalId":164619,"journal":{"name":"Unmanned Syst.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114467617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 26

A Nonlinear H-infinity Control Approach for Autonomous Truck and Trailer Systems 自动驾驶卡车和挂车系统的非线性h∞控制方法

Unmanned Syst. Pub Date : 2020-01-01 DOI: 10.1142/s2301385020500041

G. Rigatos, P. Siano, P. Wira, K. Busawon, R. Binns

{"title":"A Nonlinear H-infinity Control Approach for Autonomous Truck and Trailer Systems","authors":"G. Rigatos, P. Siano, P. Wira, K. Busawon, R. Binns","doi":"10.1142/s2301385020500041","DOIUrl":"https://doi.org/10.1142/s2301385020500041","url":null,"abstract":"A nonlinear optimal control method is developed for autonomous truck and trailer systems. Actually, two cases are distinguished: (a) a truck and trailer system that is steered by the front wheels of its truck, (b) an autonomous fire-truck robot that is steered by both the front wheels of its truck and by the rear wheels of its trailer. The kinematic model of the autonomous vehicles undergoes linearization through Taylor series expansion. The linearization is computed at a temporary operating point that is defined at each time instant by the present value of the state vector and the last value of the control inputs vector. The linearization is based on the computation of Jacobian matrices. The modeling error due to approximate linearization is considered to be a perturbation that is compensated by the robustness of the control scheme. For the approximately linearized model of the autonomous vehicles an H-infinity feedback controller is designed. This requires the solution of an algebraic Riccati equation at each iteration of the control algorithm. The stability of the control loop is confirmed through Lyapunov analysis. It is shown that the control loop exhibits the H-infinity tracking performance which implies elevated robustness against modeling errors and external disturbances. Moreover, under moderate conditions the global asymptotic stability of the control loop is proven. Finally, to implement state estimation-based control for the autonomous vehicles, through the processing of a small number of sensor measurements, the H-infinity Kalman Filter is proposed.","PeriodicalId":164619,"journal":{"name":"Unmanned Syst.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122386525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Maximal Distance Discounted and Weighted Revisit Period: A Utility Approach to Persistent Unmanned Surveillance 最大距离贴现和加权重访周期:一种持久无人监视的实用方法

Unmanned Syst. Pub Date : 2019-09-17 DOI: 10.1142/S2301385019500079

C. Olsen, K. Kalyanam, W. Baker, D. Kunz

{"title":"Maximal Distance Discounted and Weighted Revisit Period: A Utility Approach to Persistent Unmanned Surveillance","authors":"C. Olsen, K. Kalyanam, W. Baker, D. Kunz","doi":"10.1142/S2301385019500079","DOIUrl":"https://doi.org/10.1142/S2301385019500079","url":null,"abstract":"Autonomous unmanned vehicles are well suited for long-endurance, persistent intelligence, surveillance and reconnaissance (PISR) missions. In order to conduct missions, vehicles must implement a method of task selection. We propose the Maximal Distance Discounted & Weighted Revisit Period ([Formula: see text]) utility function as a solution. We derive [Formula: see text] as a zeroth-order approximation to an infinite horizon solution of PISR when formulated as a dynamic programming (DP) problem. We then use the DP solution to develop a heuristic utility function for autonomous task selections, with the goal of minimizing the prioritized revisit time to each task. Our function adapts to different task maps and task priorities, is scalable in the number of tasks, and is robust to the ad-hoc addition or removal of tasks. We demonstrate how the [Formula: see text] parameters influence vehicle behavior. We also prove that the policy results in steady-state task selections that are periodic and that such periodicity occurs regardless of initial conditions. We then demonstrate periodicity via numerical simulations on a set of test scenarios. We present a two-step heuristic methodology for selecting utility function parameters that deliver empirically good performance, which we demonstrate through a simulation-based comparison to a single-vehicle Traveling Salesman Problem (TSP) solution. The comparisons are based on four sample task maps designed to resemble operational scenarios.","PeriodicalId":164619,"journal":{"name":"Unmanned Syst.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114226747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Failsafe Mechanism Design for Autonomous Aerial Refueling using State Tree Structures 基于状态树结构的自主空中加油故障安全机制设计

Unmanned Syst. Pub Date : 2019-09-17 DOI: 10.1142/S2301385019500109

K. Dong, Q. Quan, W. Wonham

{"title":"Failsafe Mechanism Design for Autonomous Aerial Refueling using State Tree Structures","authors":"K. Dong, Q. Quan, W. Wonham","doi":"10.1142/S2301385019500109","DOIUrl":"https://doi.org/10.1142/S2301385019500109","url":null,"abstract":"Autonomous Aerial Refueling (AAR) is vulnerable to various failures and involves cooperation among autonomous receivers, tankers and remote pilots. Dangerous flight maneuvers may be executed when unexpected failures or command conflicts happen. To solve this problem, a failsafe mechanism based on State Tree Structures (STS) is proposed. The failsafe mechanism is a control logic that guides what subsequent actions the autonomous receiver should take, by observing real-time information of internal low-level subsystems such as guidance and drogue&probe and external instructions from tankers and pilots. To generate such a controller using STS, the AAR procedure is decomposed into several modes, and safety issues related with seven low-level subsystems are summarized. Then common functional demands and safety requirements are textually described. On this basis, the AAR plants and specifications are modeled by STS, and a supervisor is synthesized to control the AAR model. To prove its feasibility and correctness, a simulation environment incorporating such a logic supervisor is built and tested. The design procedures presented in this paper can be used in decision-making strategies for similar flight tasks. Supporting materials can be downloaded in Github, [ https://github.com/KevinDong0810/Failsafe-Design-for-AAR-using-STS ] including related software, input documents and output files.","PeriodicalId":164619,"journal":{"name":"Unmanned Syst.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128353735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Design of a Hybrid Aerial Robot with Multi-Mode Structural Efficiency and Optimized Mid-Air Transition 具有多模态结构效率和优化半空过渡的混合航空机器人设计

Unmanned Syst. Pub Date : 2019-09-17 DOI: 10.1142/S2301385019500067

Jun En Low, D. S. B. Shaiful, Luke Thura Soe Win, G. Soh, S. Foong

引用次数: 5

Influence of Propeller Overlap on Large-Scale Tandem UAV Performance 螺旋桨重叠对大型串联无人机性能的影响

Unmanned Syst. Pub Date : 2019-09-17 DOI: 10.1142/S2301385019500092

A. Weishäupl, S. Prior

引用次数: 3