The article represents a method to perform the Shape From Silhouette (SFS) of human, based on gravity sensing. A network of cameras is used to observe the scene. The extrinsic parameters among the cameras are initiall...
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The article represents a method to perform the Shape From Silhouette (SFS) of human, based on gravity sensing. A network of cameras is used to observe the scene. The extrinsic parameters among the cameras are initially unknown. An IMU is rigidly coupled to each camera in order to provide gravity and magnetic data. By applying a data fusion between each camera and its coupled IMU, it becomes possible to consider a downward-looking virtual camera for each camera within the network. Then extrinsic parameters among virtual cameras are estimated using the heights of two 3D points with respect to one camera within the network. Registered 2D points on the image plane of each camera is reprojected to its virtual camera image plane, using the concept of infinite homography. Such a virtual image plane is horizontal with a normal parallel to the gravity. The 2D points from the virtual image planes are back-projected onto the 3D space in order to make conic volumes of the observed object. From intersection of the created conic volumes from all cameras, the silhouette volume of the object is obtained. The experimental results validate both feasibility and effectiveness of the proposed method.
In this paper we present a multistage method applied in pedestrian detection using information from a LIDAR and a monocular-camera mounted on an electric vehicle driving in urban scenarios. The proposed method is a ca...
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In this paper we present a multistage method applied in pedestrian detection using information from a LIDAR and a monocular-camera mounted on an electric vehicle driving in urban scenarios. The proposed method is a cascade of classifiers trained in two subsets of features, one with laser-based features and the other with a set of image-based features. A specific training approach was developed to adjust the cascade stages in order to enhance the classification performance. The proposed method differs from the conventional cascade regarding the way the selected samples are propagated through the cascade. Thus, the subsequent stages of the proposed cascade receive both negatives and positives from previous ones, relying on a decision margin process. Experiments were conducted in off-line mode, for a set of single component classifiers and for the proposed cascade technique. The results are compared in terms of classification performance metrics and ROC curves.
This paper proposes a new approach for the Power Spectrum (PS)-based feature extraction applied to probabilistic Laban Movement Analysis (LMA), for the sake of human behaviour understanding. A Bayesian network is pres...
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This paper proposes a new approach for the Power Spectrum (PS)-based feature extraction applied to probabilistic Laban Movement Analysis (LMA), for the sake of human behaviour understanding. A Bayesian network is presented to understand human action and behaviour based on 3D spatial data and using the LMA concept which is a known human movement descriptor. We have two steps for the classification process. The first step is estimating LMA parameters which are built to describe human motion situation by using some low level features. Then by having these parameters, it is possible to classify different human actions and behaviours. Here, a sample of using 3D acceleration data of six body parts to obtain some LMA parameters and understand some performed actions by human is shown. A new approach is applied to extract features from a signal data such as acceleration using the PS technique to achieve some of LMA parameters. A number of actions are defined, then a Bayesian network is used in learning and classification process. The experimental results prove that the proposed method is able to classify actions.
This paper describes a Player/Stage simulation framework for mobile robot olfactory experiments. The PlumeSim framework simulates odor transport in the environment, as well as olfactory detection systems. The odor tra...
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This paper describes a Player/Stage simulation framework for mobile robot olfactory experiments. The PlumeSim framework simulates odor transport in the environment, as well as olfactory detection systems. The odor transport can be based on analytical theoretical models, data generated by dedicated computational fluid dynamics (CFD) software packages, or data acquired in a real environment. The framework is validated through comparison of the results of simulated and real mobile robot olfactory experiments.
An approach to increase road capacity consists in making vehicles move much closer to each other, i.e. using platoons, and to avoid the constant stop-and-go in urban traffic. This paper addresses the studies of new mo...
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An approach to increase road capacity consists in making vehicles move much closer to each other, i.e. using platoons, and to avoid the constant stop-and-go in urban traffic. This paper addresses the studies of new models to allow the research of cooperative and autonomous communication-enabled vehicles, with platooning capabilities, and the addition of new features in SUMO (Simulation for Urban MObility) to allow the simulation of those models. Simulations results of vehicle platoons using constant spacing instead of the more common constant time headway, with intervehicle communications, are reported in the paper. The platoon leaders are controlled by an external application and the simulation platform works at the subsecond level.
This paper addresses the problem of locating a single source from noisy range measurements in wireless sensor networks. An approximate solution to the maximum likelihood location estimation problem is proposed, by red...
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ISBN:
(纸本)9781424442959
This paper addresses the problem of locating a single source from noisy range measurements in wireless sensor networks. An approximate solution to the maximum likelihood location estimation problem is proposed, by redefining the problem in the complex plane and relaxing the minimization problem into semidefinite programming form. Existing methods solve the source localization problem either by minimizing the maximum likelihood function iteratively or exploiting other semidefinite programming relaxations. In addition, using squared range measurements, exact and approximate least squares solutions can be calculated. Our relaxation for source localization in the complex plane (SLCP) is motivated by the near-convexity of the objective function and constraints in the complex formulation of the original (non-relaxed) problem. Simulation results indicate that the SLCP algorithm outperforms existing methods in terms of accuracy, particularly in the presence of outliers and when the number of anchors is larger than three.
This paper describes an application of a new fault detection and isolation (FDI) technique based on set-valued observers (SVOs) to a linear parameter varying (LPV) longitudinal aircraft dynamic model. The FDI strategy...
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ISBN:
(纸本)9783902661968
This paper describes an application of a new fault detection and isolation (FDI) technique based on set-valued observers (SVOs) to a linear parameter varying (LPV) longitudinal aircraft dynamic model. The FDI strategy adopted herein computes and uses the set-valued estimates of the SVOs to eliminate models of the plant that are not compatible with the set of observations provided by the aircraft sensor suite and actuation data. The design of the SVOs takes into account model uncertainty and disturbances, thus avoiding false alarms due to such perturbations. The behavior of the proposed solution is assessed in simulation, by deliberately generating hard and soft sensor/actuator faults. The results show that the faults take, in general, only a few iterations to be detected and isolated, therefore paving the way for the use of the proposed methodology in practical applications.
This paper proposes a nonlinear control architecture for the stabilization of a quadrotor vehicle based on image measurements of a set of landmarks obtained from a pan and tilt camera. The vehicle is stabilized vertic...
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ISBN:
(纸本)9781424477456
This paper proposes a nonlinear control architecture for the stabilization of a quadrotor vehicle based on image measurements of a set of landmarks obtained from a pan and tilt camera. The vehicle is stabilized vertically using an additional vertical position sensor and lateral-longitudinal stabilization is achieved with a nested saturation control law by feedback of image measurements, body attitude, and angular rate. Additionally, the pan and tilt camera is actively actuated to to keep the landmarks visible in the image sensor for most operating conditions. Simulation results are presented to assess the performance of the proposed control architecture.
We are extremely pleased to present this special issue of the Journal of Control Theory and *** dynamic programming (ADP) is a general and effective approach for solving optimal control and estimation problems by adap...
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We are extremely pleased to present this special issue of the Journal of Control Theory and *** dynamic programming (ADP) is a general and effective approach for solving optimal control and estimation problems by adapting to uncertain environments over *** optimizes the sensing objectives accrued over a future time interval with respect to an adaptive control law,conditioned on prior knowledge of the system,its state,and uncertainties.A numerical search over the present value of the control minimizes a Hamilton-Jacobi-Bellman (HJB) equation providing a basis for real-time,approximate optimal control.
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