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Impact of Current Disturbances on AUV Docking: Model-Based Motion Prediction and Countering Approaches

IEEE JOURNAL OF OCEANIC ENGINEERING 2018年第4期43卷 888-904页

作者： Fan, Shuangshuang Li, Bo Xu, Wen Xu, Yuanxin Zhejiang Univ Coll Informat Sci & Elect Engn Hangzhou 310027 Zhejiang Peoples R China Univ Tasmania Australian Maritime Coll Launceston Tas 7250 Australia Key Lab Ocean Observat Imaging Testbed Testbed Zh Zhoushan 316021 Peoples R China

Underwater docking enables autonomous underwater vehicles (AUVs) to operate independently of a surface vessel for extended periods. To perform the clocking mission, special attention has to he paid to the navigation, guidance, and control issues of the vehicle, especially under current disturbances. Based on a hill dynamic model of an AUV in currents, this paper studies the influences of current disturbances on AUV docking motion. A comprehensive docking scheme is introduced, which combines Kalman filter type navigation, guidance with current compensation, and proportional-integral-derivative (PID) controllers for both cross-track and heading control, to ensure successful docking operations. To counter the current effects, the proposed guidance algorithm applies current estimation and attitude compensation for motion correction online;in addition, an upstream control strategy in the case of strong current is also discussed. The proposed algorithms are initially validated through model-based numerical simulations, which provide effective guidance for the succeeding docking experiments conducted in a current generating pool. The feasibility and effectiveness of the countering approaches for AUV docking under current disturbances are demonstrated during the pool trials.

关键词： Attitude compensation autonomous underwater vehicle (AUV) dynamic model in currents current estimation guidance algorithm upstream control strategy

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Three-axes predictive control of autopilot for missile

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AIRCRAFT ENGINEERING AND AEROSPACE TECHNOLOGY 2017年第1期89卷 1-10页

作者： Ada, Celal Kural, Ayhan Roketsan Missiles Inc Ballist Syst Engn Directorate Ankara Turkey Istanbul Tech Univ Dept Mech Engn Istanbul Turkey

Purpose - The purpose of this paper is to present the autopilot design for the missile under various disturbances. Design/methodology/approach - In this study, model predictive control (MPC) method has been used for autopilot design for each axis. The aim of autopilot is that to keep the roll angle value around the zero degree and to track pitch/yaw acceleration commands. This three-axes control methodology also takes into consideration the interaction between pitch, yaw and roll motions. Findings - The purpose of using MPC method for three-axes of the autopilot is to decrease the control effort and to make the close-loop system insensitive against modeling uncertainties and stochastic effects. Originality/value - This study shows that the missile is able to reach to the desired target with good robustness, low control effort and little miss-distance under disturbances such as aerodynamic uncertainties, thrust misalignment and gust affect by using this alternative control method.

关键词： Simulation Autopilot design guidance algorithm Missile dynamic Model predictive control Three-axes control

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Online trajectory planning of robot arms for interception of fast maneuvering object under torque and velocity constraints

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IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART A-SYSTEMS AND HUMANS 2005年第6期35卷 831-843页

作者： Chwa, D Kang, J Choi, JY Ajou Univ Dept Elect & Comp Engn Suwon 443749 South Korea NeoMTel Seoul 135080 South Korea Seoul Natl Univ Sch Elect Engn & Comp Sci Seoul 151742 South Korea

This paper presents a novel approach to an online trajectory planning of robot arms for the interception of a fast-maneuvering object under torque and velocity constraints. A body axis is newly introduced as a trajectory-planning coordinate in order to meet the position and the velocity matching conditions or a smooth grasp of the fast-maneuvering object. Using the position of the object and the end-effector in the inertia axis, the acceleration commands are generated in the X-, Y-, and Z-directions of the body axis and the acceleration commands are modified considering the torque and the velocity constraints. The trajectory planning in the X-direction becomes the speed planning to achieve the maximum speed, whereas the trajectory planning in the Y- and Z-directions becomes the direction planning where a missile-guidance algorithm is employed to intercept the maneuvering object. Finally, the acceleration commands in the body axis are transformed into the angle commands of the end-effector in the joint axis, which is used as the actual trajectory commands in robot arms.

关键词： fast-maneuvering object guidance algorithm online trajectory planning robot arms torque and velocity constraints

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Analysis and design of aerocapture tether with accounting for stochastic errors

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JOURNAL OF SPACECRAFT AND ROCKETS 1998年第5期35卷 683-689页

作者： Tragesser, SG Longuski, JM Purdue Univ Sch Aeronaut & Astronaut W Lafayette IN 47907 USA

As an alternative to conventional aerocapture spacecraft, a system comprising two vehicles (a probe and an orbiter) connected by a long thin tether has been proposed. In this tethered system, the probe provides the necessary atmospheric drag while the orbiter remains high above the sensible atmosphere. The results of a sensitivity analysis of the aerocapture tether are presented. Errors in knowledge of the atmosphere and in control of the initial conditions are considered. A result of the analysis is the discovery that the tethered system possesses a self-correcting mechanism that partially compensates for these errors. This intrinsic characteristic can be enhanced with a simple guidance algorithm that implements a change in the tether length to minimize the effect of off-nominal conditions. Design rules are developed to accommodate stochastic errors without violating the constraints, i.e., breaking or compressing the tether, subjecting the orbiter to atmospheric effects, crashing, or failing to capture. The final design consists of a 68-km tether with a mass of 381 kg and a probe and orbiter of 1000 kg each. It is capable of achieving a 99% success rate for aerocapture at Mars.

关键词： Aerobraking tethers guidance algorithm Mars Exploration Atmosphere System Probe Entry Mass atmosphere Exploration accounting orbit vehicle Mars Random error aerocapture entry

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Model for Simulating Fasting Glucose in Type 2 Diabetes and the Effect of Adherence to Treatment

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IFAC-PapersOnLine 2017年第1期50卷 15086-15091页

作者： Aradóttir, Tinna B. Boiroux, Dimitri Bengtsson, Henrik Kildegaard, Jonas Orden, Brad V. Jørgensen, John B. Department of Applied Mathematics and Computer Science Technical University of Denmark Kgs. Lyngby DK-2800 Denmark Novo Nordisk A/S BagsværdDK-2880 Denmark

The primary goal of this paper is to predict fasting glucose levels in type 2 diabetes (T2D) in long-acting insulin treatment. The paper presents a model for simulating insulin-glucose dynamics in T2D patients. The model combines a physiological model of type 1 diabetes (T1D) and an endogenous insulin production model in T2D. We include a review of sources of variance in fasting glucose values in long-acting insulin treatment, with respect to dose guidance algorithms. We use the model to simulate fasting glucose levels in T2D long-acting insulin treatment and compare the results with clinical trial results where a dose guidance algorithm was used. We investigate sources of variance and through simulations evaluate the contribution of adherence to variance and dose guidance quality. The results suggest that the model for simulation of T2D patients is sufficient for simulating fasting glucose levels during titration in a clinical trial. Adherence to insulin injections plays an important role considering variance in fasting glucose. For adherence levels 100%, 70% and 50%, the coefficient of variation of simulated fasting glucose levels were similar to observed variances in insulin treatment. The dose guidance algorithm suggested too large doses in 0.0%, 5.3% and 24.4% of cases, respectively. Adherence to treatment is an important source of variance in long-acting insulin titration. © 2017

关键词： Physiological models Glucose Insulin Medical applications Medical problems Physiology Titration Biomedical systems Coefficient of variation guidance algorithm Insulin injections Insulin treatment Modeling for simulations Production modeling Type 2 diabetes

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Imaging infrared seeker design and tests for FOK guided missile 34

Imaging infrared seeker design and tests for FOK guided miss...

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Conference on Infrared Imaging Systems - Design, Analysis, Modeling, and Testing XXXIV

作者： Leshchenko, Yelyzaveta Kaczmarek, Kacper Labaj, Filip Malecki, Szymon Miedzinski, Dariusz Sochacki, Mateusz Warsaw Univ Technol Inst Micromech & Photon Fac Mechatron Student Club Photon Engn SPIE & Opt Chapter Andrzeja Boboli 8 PL-02525 Warsaw Poland Warsaw Univ Technol Fac Power & Aeronaut Engn Students Space Assoc Nowowiejska 21-25 PL-00665 Warsaw Poland Warsaw Univ Technol Inst Microelect & Optoelect Doctoral Sch Koszykowa 75 PL-00662 Warsaw Poland Polish Armaments Grp SA Nowy Swiat 4 PL-00497 Warsaw Poland Warsaw Univ Technol Fac Power & Aeronaut Engn Inst Aeronaut & Appl Mech Div Mech Nowowiejska 24 PL-00665 Warsaw Poland Warsaw Univ Technol Fac Power & Aeronaut Engn Inst Aeronaut & Appl Mech Div Automat & Aeronaut Syst Nowowiejska 24 PL-00665 Warsaw Poland

ISBN: (纸本)9781510661806;9781510661813

The design, development and performance evaluation of an imaging infrared seeker system of the FOK missile will be presented in this paper. FOK is a guided missile iteratively developed since 2017 by the Students' Space Association at Warsaw University of Technology, designed as a testbed for the development of control algorithms. Throughout the years of development the design evolved, and currently assumes the incorporation of an electro-optical seeker, enabling the missile to actively search and track ground-based targets. An infrared detection module was chosen as the core sensing component of the system. The module consists of an uncooled 640x512 microbolometer detector array integrated with dedicated optics, providing a high-resolution image in the 8-12 mu m spectral range. Since the seeker will be mounted at the front of the missile, an IR-transparent nose cone dome was required as part of the optical system. Two dome variants were designed, made out of silicon and germanium, respectively. Optical parameters of the imaging system, composed of the dome - objective - microbolometer array were calculated and confirmed using ray-tracing software. The designed domes were optimized in order to minimize image quality degradation. Key parameters considered during the calculations included: optical aberrations, modulation transfer function - MTF and field of view - FOV. Software-in-the-loop tests with the use of in-house developed simulation software will be performed together with hardware-in-the-loop tests based on capturing real images obtained by the tested system installed under a UAV. The tests' goal was to check the performance of the developed guidance algorithms in an operational-like environment.

关键词： electro-optical seeker missile guidance guidance algorithm thermal imaging long-wave infrared infrared optics microbolometers focal plane array image processing

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Ballistic missile intercept from UCAV

Ballistic missile intercept from UCAV

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作者： Lu, Zheng Liang Naval Postgraduate School

学位级别：硕士

The objective of this thesis is to conduct a study to evaluate the feasibility of the hit-to-kill trajectory-shaping(TS) guidance of an air-launched missile from a UCAV against enemy ballistic missiles via computer simulation, using a TS-guidance algorithm developed by LT Lukacs and Prof Yakimenko based on the direct method of calculus of variations that maximizes the kinetic energy transfer of an air-launched missile against an aerial target. The computer simulation code will generate the air-launched missile's entire flight path in order to minimize the distance travelled by the air-launched missile, minimize the time to intercept, and maximize kinetic energy transfer to the target (a simulated enemy missile) by controlling the interception geometry while providing near-optimal flight path to interception. This will be done by utilizing the direct method of calculus of variations combined with inverse dynamics theory to generate, in real time, an optimal flight path using the missile's onboard sensors and computers. The results have confirmed the feasibility of hit-to-kill trajectory-shaping(TS) guidance of an air-launched anti-ballistic missile from a UCAV.

关键词： Ballistic Missile Interception UCAV Trajectory-Shaping guidance algorithm Direct Method of Calculus

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Collision Avoidance of Hexacopter UAV Based on LiDAR Data in Dynamic Environment

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REMOTE SENSING 2020年第6期12卷 975-975页

作者： Park, Jongho Cho, Namhoon Ajou Univ Dept Mil Digital Convergence Suwon 16499 South Korea Agcy Def Dev 1st R&D Inst Daejeon 34186 South Korea

A reactive three-dimensional maneuver strategy for a multirotor Unmanned Aerial Vehicle (UAV) is proposed based on the collision cone approach to avoid potential collision with a single moving obstacle detected by an onboard sensor. A Light Detection And Ranging (LiDAR) system is assumed to be mounted on a hexacopter to obtain the obstacle information from the collected point clouds. The collision cone approach is enhanced to appropriately deal with the moving obstacle with the help of a Kalman filter. The filter estimates the position, velocity, and acceleration of the obstacle by using the LiDAR data as the associated measurement. The obstacle state estimate is utilized to predict the future trajectories of the moving obstacle. The collision detection and obstacle avoidance maneuver decisions are made considering the predicted trajectory of the obstacle. Numerical simulations, including a Monte Carlo campaign, are conducted to verify the performance of the proposed collision avoidance algorithm.

关键词： unmanned aerial vehicle hexacopter collision avoidance guidance algorithm dynamic environment

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Reactive Collision Avoidance algorithm for UAV Using Bounding Tube Against Multiple Moving Obstacles

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IEEE ACCESS 2020年 8卷 218131-218144页

作者： Park, Jongho Cho, Namhoon Lee, Seokwon Ajou Univ Dept Mil Digital Convergence Suwon 16499 South Korea Agcy Def Dev 1st Res & Dev Inst Daejeon 34186 South Korea Cranfield Univ Sch Aerosp Transport & Mfg Cranfield MK43 0AL Beds England

A reactive collision avoidance algorithm is proposed to enable safe autonomous flight in the presence of multiple dynamic obstacles. A position-controlled hexacopter equipped with a visual sensor obtaining obstacle information is considered as an Unmanned Aerial Vehicle (UAV) platform. The proposed method centers on the concept of bounding tube which intrinsically extends the static bounding box to incorporate forthcoming movement of the obstacles into the collision avoidance framework. The processing pipeline consists of separate components for each of the sequential tasks in obstacle sensing and tracking. Computation of a spherical bounding box for each obstacle is followed by discrete-time Kalman filtering for prediction of obstacle trajectory to detect potential collision. If the current course of UAV turns out highly likely to end in collision with any of the obstacles, the vehicle steers to an aiming point chosen from among the bundle of candidates produced by constructing a bounding tube that takes account of predicted obstacle motion. The bounding-tube-based aiming point generation extends seamlessly to the case with multiple moving obstacles through running in series with multi-obstacle track management that combines hierarchical clustering of sensory data points for obstacle identification and a simple geometric method for data association. Numerical simulations are conducted to verify the performance of the proposed collision avoidance algorithm.

关键词： Collision avoidance Heuristic algorithms Vehicle dynamics Unmanned aerial vehicles Electron tubes Sensors Clustering algorithms Reactive collision avoidance guidance algorithm multiple obstacles dynamic environment unmanned aerial vehicle

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