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AUV Terrain-Aided Doppler Navigation using Complementary Filtering

IFAC Proceedings Volumes 2012年第27期45卷 313-318页

作者： Francisco Curado Teixeira João Quintas António Pascoal Center for Environmental and Marine Studies and Dept. GeoSciences University of Aveiro Campus Universitário de Santiago 3810 - 193 Aveiro Portugal Institute for Systems and Robotics and Dept. Electrical Engineering Instituto Superior Técnico Av. Rovisco Pais 1 1049 - 001 Lisboa Portugal

This paper addresses the challenging problem of achieving truly autonomous long-range navigation of underwater vehicles relying on affordable navigation sensors. Terrain-aided navigation (TAN) is a methodology that holds potential to solve this problem by dispensing with the need to use high-grade, inertial navigation sensors and the deployment and calibration of acoustic beacons. To implement TAN without incurring the additional cost of expensive dedicated sensors, we propose the utilization of a Doppler velocity logger (DVL) which is an equipment of widespread utilization in oceanography and also a standard instrument in underwater navigation. We avail ourselves of a less exploited characteristic of DVL sensors that consists in the ability to acquire, simultaneously with the velocity data, a set of accurate range measurements relatively to a reflective interface. The combination of these sensing capacities enables Doppler units to be used not only in dead-recknoning navigation but also in terrain-based localization of underwater vehicles. The main contribution of the paper is the design of a complementary filter (CF) for fusion of TAN estimates with DVL measurements. The CF approach is motivated by the need to reduce the short-term variability of position estimates that is typically observed in conventional TAN. The solution proposed is analysed in comparison with a well-known Rao-Blackwellized particle filter set-up which is shown to implement a data fusion filter designed in a stochastic estimation framework. The results obtained in Monte Carlo simulations performed with real bathymetric data evidence the superior performance of the complementary filter approach in terms of position estimation accuracy and long term output signal stability.

关键词： Doppler-based navigation terrain-aided navigation complementary filtering particle filters

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Scheduling Measurements and Controls over Networks - Part I: Rollout Strategies for Protocol Design

Scheduling Measurements and Controls over Networks - Part I:...

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American Control Conference

作者： D. J. Antunes W. P. M. H. Heemels J. P. Hespanha C. J. Silvestre Hybrid and Networked Systems Group Department of Mechanical Engineering Eindhoven University of Technology the Netherlands Dept. of Electrical and Computer Eng. University of California Santa Barbara CA 93106-9560 USA Institute for Systems and Robotics Instituto Superior Tecnico 1046-001 Lisboa Portugal

ISBN: (纸本)9781457710957

We consider networked control systems where nodes (sensors, actuators, and controller) are connected via a communication network that allows only one user to transmit at a given time. We tackle the scheduling problem of deciding which node should access the network at each transmission time so as to optimize a quadratic performance objective. Using the framework of dynamic programming, we propose a rollout strategy by which the node elected to transmit at each step is the one that leads to optimal performance over a lookahead horizon assuming that from then on nodes transmit in a periodic order. The proposed strategy leads to a protocol in which a conic state partition determines which node transmits at each step and which can outperform any given periodic protocol. Moreover, we show that some of the protocols previously proposed in the literature, such as the Maximum Error First and the dynamic protocols, can be viewed as rollout strategies for a certain dynamic programming problem. The advantages of using rollout strategies are illustrated by a numerical example.

关键词： Protocols Networked control systems Actuators Sensors Vectors Dynamic programming Stability analysis

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A Novel Particle Filter Formulation with Application to Terrain-Aided Navigation

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IFAC Proceedings Volumes 2012年第5期45卷 132-139页

作者： Francisco Curado Teixeira António Pascoal Pramod Maurya Center for Environmental and Marine Studies and Dept GeoSciences University of Aveiro Campus Universitáario de Santiago 3810 - 193 Aveiro Portugal Institute for Systems and Robotics and Dept. Electrical Engineering Instituto Superior Técnico Av. Rovisco Pais 1 1049 - 001 Lisboa Portugal National Institute of Oceanography Marine Instrumentation Division Dona Paula Goa - 403004 India

Terrain-aided navigation (TAN) holds high potential for integration with classical dead-reckoning methods in underwater vehicles that do not have access to the global positioning system (GPS). The TAN approach constitutes an economical solution for long-range oceanographic missions that cannot afford the cost of high-grade inertial navigation systems or the logistics associated to the deployment of long acoustic baselines. Successful implementations of the terrain navigation concept require efficient and robust algorithms for estimation of the vehicle kinematic states. Current implementations of terrain-based navigation rely essentially on a class of nonlinear filters commonly designated particle filters (PF) due to their versatility and robustness. However, there are some typical problems posed by TAN applications that require further investigation since they are not adequately solved by standard PF algorithms. The present paper addresses the problem of efficiency and robustness of particle filters in the context of terrain based navigation. To this effect, we present two new filter versions that are shown to be more robust and to achieve superior performance in terms of position and velocity estimation. When applied to TAN, the new PF formulations mitigate filter divergence problems frequently caused by terrain symmetries and are more robust than other well-known versions when used in scenarios with poor terrain information.

关键词： Bayesian estimation importance sampling particle filter terrain-aided navigation

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Power Flow Control for Quasi-Z Source Inverter with Battery based PV Power Generation System

Power Flow Control for Quasi-Z Source Inverter with Battery ...

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2011 IEEE Energy Conversion Congress and Exposition (ECCE 2011)

作者： Dongsen Sun Baoming Ge Fang Z. Peng Haitham Abu Rub Anibal T. de Almeida School of Electrical Engineering Beijing Jiaotong University Beijing China Dept. of Electrical and Computer Engineering Michigan State University East Lansing Michigan USA Dept. of Electrical & Computer Engineering Texas A&M University at Qatar Doha Qatar Institute of Systems and Robotics University of Coimbra Coimbra Portugal

ISBN: (纸本)9781457705427

This paper presents a new power interface applied in photovoltaic (PV) power generation system-quasi-Z source inverter (qZSI) with a battery. In this topology, a battery is directly connected with a capacitor of qZSI network for energy storage. First, the configuration of the new system is designed and its operating principle is analyzed. Owing to the battery, the generation system can generate the desired stable grid power even if the PV panel output energy varies. An energy management is proposed to control the system while taking into account battery safety. With the energy management, the system can regulate the power flow to secure the battery from over charging or over discharging. This study explores a whole control for the PV generation system, including Perturb and Observe (P&O) method for MPPT control of PV panel, the grid-injected power control, and energy management control for battery safety operating. Several cases are simulated in MATLAB to verify the proposed control strategies. The results demonstrate that the whole system can operate effectively and safely, due to the proposed energy management.

关键词： Batteries Energy management System-on-a-chip Inverters Power generation Safety Capacitors

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SVR sagittal balance of a biped robot controlling the torso and ankle joint angles

SVR sagittal balance of a biped robot controlling the torso ...

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IEEE International Conference on Industrial engineering and engineering Management, IEEM2010

作者： Ferreira, J.P. Crisóstomo, M.M. Coimbra, A.P. Inst. of Systems and Robotics Dept. of Electrical and Computer Eng. Univ. of Coimbra Portugal Dept. of Electrical Engmeenng Supenor Institute of Engineering of Coimbra Coimbra Portugal

ISBN: (纸本)9781424485031

关键词： Intelligent robots

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Path planning for robot navigation using view sequences

Path planning for robot navigation using view sequences

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作者： Mendes, Mateus Coimbra, A. Paulo Crisóstomo, Manuel M. ISR - Institute of Systems and Robotics Dept. of Electrical and Computer Engineering University of Coimbra Portugal ESTGOH Polytechnic Institute of Coimbra Portugal

ISBN: (纸本)9789881701299

Navigation based on visual memories is very common among humans. However, planning long trips requires also a more sophisticated representation of the environment, such as a topological map. This paper describes a system that learns paths by storing sequences of images and image information in a Sparse Distributed Memory. Connections between paths are detected by exploring similarities in the images, and a topological representation of the connections is created. The robot is then able to plan paths and skip from one path to another at the connection points. The system was tested under reconstitutions of country and urban environments, and it was able to successfully plan paths and navigate.

关键词： Motion planning

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SVR control of the sagittal balance of a biped robot combining torso and ankle joints

SVR control of the sagittal balance of a biped robot combini...

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作者： Ferreira, João P. Crisóstomo, Manuel Coimbra, A. Paulo Inst. of Systems and Robotics Dept. of Electrical and Computer Eng. Univ. of Coimbra Portugal Dept. of Electrical Engineering Superior Institute of Engineering of Coimbra Coimbra Portugal

ISBN: (纸本)9781424496730

This paper describes the control of an autonomous biped robot that combines the use of the torso and the ankle joints movements for its sagittal balance. The innovative characteristic of this controller is the combined use of the ankle and torso joints movements to correct the Zero Moment Point (ZMP). It is used an artificial intelligence technique, the Support Vector Regression (SVR), to control the balance of the robot. The relation between torso and ankle compensations was obtained using the traditional inverted pendulum method. The use of the ankle joint for balance control implies the real time change of the designed initial gait but presents a lower angle control variation compared to the use of the torso joint which is simpler and more precise but slower and with a lower ZMP compensation range. Combining the two control methods it is possible to achieve better results. To obtain a good stable step it is very important to have a good initial legs trajectory design. With that purpose in mind human-based trajectories were used, leading to smaller control corrections of ankle and torso joints. It were tested different combinations of torso and ankle joints corrections for the balance control on flat horizontal and inclined surfaces and the results presented. In order to evaluate and compare the performance of the balance control methods of a biped robot two performance indexes are proposed.

关键词： Inverted pendulum

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Change detection in 3D environments based on Gaussian mixture model and robust structural matching for autonomous robotic applications

Change detection in 3D environments based on Gaussian mixtur...

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23rd IEEE/RSJ 2010 International Conference on Intelligent Robots and systems, IROS 2010

作者： Núñez, P. Drews Jr., Paulo Bandera, A. Rocha, R. Campos, M. Dias, J. ISIS Group Universidad de Málaga Spain Robolab Group Dept. Tecnología de Los Computadores y Las Comunicaciones Universidad de Extremadura Spain Dept. Computer Science Federal University of Minas Gerais Brazil Institute of Systems and Robotics Dept. Electrical and Computer Engineering University of Coimbra Portugal

ISBN: (纸本)9781424466757

The ability to detect perceptions which were never experienced before, i.e. novelty detection, is an important component of autonomous robots working in real environments. It is achieved by comparing current data provided by its sensors with a previously known map of the environment. This often constitutes an extremely challenging task due to the large amounts of data that must be compared in real-time. With respect to previously proposed approaches, this paper detects changes in 3D environment based on probabilistic models, the Gaussian Mixture Model, and a fast and robust combined constraint matching algorithm. The matching allows to represent the scene view as a graph which emerges from the comparison between Mixtures of Gaussians. Finding the largest set of mutually consistent matches is equivalent to find the maximum clique on a graph. The proposed approach has been tested for mobile robotics purposes in real environments and compared to other matching algorithms. Experimental results demonstrate the performance of the proposal. ©2010 IEEE.

关键词： Gaussian distribution

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Exploration of Kinematic Optimal Control on the Lie Group SO (3) *

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IFAC Proceedings Volumes 2010年第14期43卷 1302-1307页

作者： Alessandro Saccon John Hauser A. Pedro Aguiar Institute for Systems and Robotics (ISR) Instituto Superior Técnico (IST) Lisboa Dept. of Electrical Computer and Energy Engineering University of Colorado Boulder

In this paper, we investigate a generalization of the infinite time horizon linear quadratic regulator (LQR) for systems evolving on the special orthogonal group SO(3). Using Pontryagin's Maximum Principle, we derive the necessary conditions for optimality and the associated Hamiltonian equations. For a special class of weighting matrices, we show that the optimal feedback can be computed explicitly and we prove that the non differentiable value function is the viscosity solution of an appropriate Hamiltn-Jacobi-Bellman equation on SO(3). For arbitrary positive definite weighting matrices, numerical simulations allow us to explore the relationship between the optimal trajectories and weighting matrices, and in particular to highlight nontrivial non differentiability properties of the value function.

关键词： Optimal control Special orthogonal group SO(3) Rotation matrices Lie groups Pontryagin's Maximum Principle Hamilton-Jacobi-Bellman equation

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Multiple marine vehicle deconicted path planning with currents and communication constraints

Multiple marine vehicle deconicted path planning with curren...

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作者： Häusler, Andreas J. Ghabcheloo, Reza Pascoal, António M. Aguiar, A. Pedro Institute for Systems and Robotics Dept. of Electrical Engineering Instituto Superior Técnico Av. Rovisco Pais No. 1 1049-001 Lisboa Portugal Department of Intelligent Hydraulics and Automation Tampere Univ. of Technology P.O. Box 589 33101 Tampere Finland

ISBN: (纸本)9783902661876

Recent research in multiple autonomous marine vehicle (AMV) applications shows that versatile path planning algorithms are of crucial importance to cooperative control scenarios. These algorithms need to be lightweight in terms of running time and capable of incorporating different factors inuencing a given mission, like AMV dynamic constraints and environmental conditions. In addition, the path planner needs to take into account requirements imposed by multiple vehicle scenarios (of which collision avoidance is an important issue), and inter-vehicle communication constraints. Mission-related measures have to be incorporated additionally, such as minimization of energy usage over all participating AMVs, and simultaneous arrival of the AMVs at their designated target destinations, to name but a few. These aspects pose considerable challenges both from a theoretical and practical implementation standpoint. This paper presents a versatile path planning algorithm for deconicted multiple AMV missions at sea, incorporating single vehicle dynamical constraints as well as an inter-vehicle communication constraint. Additionally, it takes into account unknown constant ocean currents, and gives an overview on time-coordinated path following, a a closed-loop methodology to execute the planned mission, reducing the need for replanning in the presence of disturbances. The paper finishes with an outlook on important future directions to advance the algorithm.

关键词： Motion planning

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