The technology of hydrodynamic modeling and marine craft motion control systems has progressed greatly in recent years. This timely survey includes the latest tools for analysis and design of advanced guidance, navigation and control systems and presents new material on underwater vehicles and surface vessels. Each section presents numerous case studies and applications, providing a practical understanding of how model-based motion control systems are designed.

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Handbook of Marine Craft Hydrodynamics and Motion Control: Fossen/Handbook of Marine Craft Hydrodynamics and Motion Control

A wavelet-based image fusion tutorial

We review a range of techniques related to navigation of unmanned vehicles through unknown environments with obstacles, especially those that rigorously ensure collision avoidance (given certain assumptions about the system). This topic continues to be an active area of research, and we highlight some directions in which available approaches may be improved. The paper discusses models of the sensors and vehicle kinematics, assumptions about the environment, and performance criteria. Methods applicable to stationary obstacles, moving obstacles and multiple vehicles scenarios are all reviewed. In preference to global approaches based on full knowledge of the environment, particular attention is given to reactive methods based on local sensory data, with a special focus on recently proposed navigation laws based on model predictive and sliding mode control.

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Algorithms for collision-free navigation of mobile robots in complex cluttered environments: a survey

https://www.gastrojournal.org/article/S0016-5085(09)00999-8/pdf

Endoscopist-Directed Administration of Propofol: A Worldwide Safety Experience

Multi-temporal mapping of the vegetation fraction in early-season wheat fields using images from UAV

This paper presents a path planner for multiple unmanned aerial vehicles (UAVs) based on evolutionary algorithms (EAs) for realistic scenarios. The paths returned by the algorithm fulfill and optimize multiple criteria that 1) are calculated based on the properties of real UAVs, terrains, radars, and missiles and 2) are structured in different levels of priority according to the selected mission. The paths of all the UAVs are obtained with the multiple coordinated agents coevolution EA (MCACEA), which is a general framework that uses an EA per agent (i.e., UAV) that share their optimal solutions to coordinate the evolutions of the EAs populations using cooperation objectives. This planner works offline and online by means of recalculating parts of the original path to avoid unexpected risks while the UAV is flying. Its search space and computation time have been reduced using some special operators in the EAs. The successful results of the paths obtained in multiple scenarios, which are statistically analyzed in the paper, and tested against a simulator that incorporates complex models of the UAVs, radars, and missiles, make us believe that this planner could be used for real-flight missions.

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Evolutionary Trajectory Planner for Multiple UAVs in Realistic Scenarios

Modeling and simulation of a gas distribution pipeline network

A mathematical model for planning transportation of multiple petroleum products in a multi-pipeline system

Highlights? We design an Expert System for plant discrimination in agricultural fields. ? A decision making module determines the image quality. ? A greenness identification module extracts green plants. ? The Expert System is valid under adverse conditions and different devices. ? Plants segmentation is required for weeds specific treatments. It is well-known that one important issue emerging strongly in agriculture is related with the automation of tasks, where camera-based sensors play an important role. They provide images that must be conveniently processed. The most relevant image processing procedures require the identification of green plants, in our experiments they comes from barley and maize fields including weeds, so that some type of action can be carried out, including site-specific treatments with chemical products or mechanical manipulations.The images come from outdoor environments, which are affected for a high variability of illumination conditions because of sunny or cloudy days or both with high rate of changes.Several indices have been proposed in the literature for greenness identification, but under adverse environmental conditions most of them fail or do not work properly. This is true even for camera devices with auto-image white balance.This paper proposes a new automatic and robust Expert System for greenness identification. It consists of two main modules: (1) decision making, based on image histogram analysis and (2) greenness identification, where two different strategies are proposed, the first based on classical greenness identification methods and the second inspired on the Fuzzy Clustering approach. The Expert System design as a whole makes a contribution, but the Fuzzy Clustering strategy makes the main finding of this paper. The system is tested for different images captured with several camera devices.

A new Expert System for greenness identification in agricultural images

A study was conducted to determine the effectiveness of using controlled flaps and a T-foil to smoothen a ship's vertical motion while navigating in head seas. The study comprised two steps: to develop a tool for control design in the form of a computer-based simulation and to use this tool to develop satisfactory controllers. The simulation was based on mathematical models of the ship, the actuators, the waves and the seasickness effect. Since the actuators have limited action, there is a limited margin for improvement based on more sophisticated control strategies. Possible improvements of motion sickness incidence (MSI) are linked to a control strategy that exploits better synchronization with incident waves.

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J.M. de la Cruz

Papers

Evolutionary Trajectory Planner for Multiple UAVs in Realistic Scenarios

Modeling and simulation of a gas distribution pipeline network

A mathematical model for planning transportation of multiple petroleum products in a multi-pipeline system

A new Expert System for greenness identification in agricultural images

Improving the comfort of a fast ferry