The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The notion of a Fast Moving Object (FMO), i.e. an object that moves over a distance exceeding its size within the exposure time, is introduced. FMOs may, and typically do, rotate with high angular speed. FMOs are very common in sports videos, but are not rare elsewhere. In a single frame, such objects are often barely visible and appear as semitransparent streaks. A method for the detection and tracking...
We present new methods of simultaneously estimating camera geometry and time shift from video sequences from multiple unsynchronized cameras. Algorithms for simultaneous computation of a fundamental matrix or a homography with unknown time shift between images are developed. Our methods use minimal correspondence sets (eight for fundamental matrix and four and a half for homography) and therefore...
This paper proposes a Newton extremum seeking algorithm based accurate global task coordinate frame (Newton-AGTCF) for precision contouring motion control of biaxial systems under complicated free-form contouring tasks. Specifically, a cost function is defined based on the reference contour and the current position. The point on the reference contour, where the minimal value of the cost function can...
We present a new method for the application of image-based river velocimetry. Our method is dedicated to high velocity river flows and it is based on an optical flow scheme. Unlike traditional Particle Image Velocimetry (PIV) methods, optical flow provides dense estimations and it is highly adaptable to different applications. We therefore propose a new physics-based optical flow derived from scalar...
The contour error is the core index to measure the machining quality, so how to get an accurate contour error value and reduce contour error is still an urgent problem in the production process, especially in high-speed and large-curvature contouring tasks. In this paper, a cross-coupled iterative learning control (CCILC) based on natural local approximation of contour error is proposed to reduce...
We generalize Richardson-Lucy (RL) deblurring to 4-D light fields by replacing the convolution steps with light field rendering of motion blur. The method deals correctly with blur caused by 6-degree-of-freedom camera motion in complex 3-D scenes, without performing depth estimation. We introduce a novel regularization term that maintains parallax information in the light field while reducing noise...
This paper deals with the scenario of two multi-UAV systems (so-called teams), each flying from a starting point to a target point. The teams meet on their ways and have to avoid collisions in the horizontal plane. Both teams work independent of each other but use the same formation-control and obstacle-collision-avoidance algorithm. The leaders measure obstacles' positions, use a Kalman Filter to...
Conventional point object model based automotive radar tracking system assumes at most one detection received from the target object at a time. However, in real applications for an extended object, such as a passenger car, located within a close range to a high-resolution radar or LIDAR, the system usually receives multiple reflections from different parts of the object. This can introduce large bias...
Under the common state space model for tracking a maneuvering target, the tracker needs to adapt its state transition model timely to match the target maneuver, which is usually carried out by finding the best one from a bank of candidate Markov models or employing all of them simultaneously but assigning different probabilities. Both methods suffer from time delay for confirming the target maneuver...
Modeling and filtering of a mobile object stochastic trajectory on the basis of fractal Wiener process taking into account the Hurst indicator are offered. For numerical realization of this processes the wavelet based decomposition is used. The peculiarities of trajectory parameters estimation by using Kalman filter and the wavelet algorithm are investigated. The illustrating examples are given.
Within the complex driving environment, progress in autonomous vehicles is supported by advances in sensing and data fusion. Safe and robust autonomous driving can only be guaranteed provided that vehicles and infrastructure are fully aware of the driving scenario. This paper proposes a methodology for feature uncertainty prediction for sensor fusion by generating neural network surrogate models directly...
This paper presents a framework of simulation-based design for robotic care devices developed to reduce the burden of caregiver and care receivers. First, physical interaction between the user and device is quantitatively estimated by using a digital human simulator. Then we introduce a method for optimizing the design parameters according to given evaluation criteria. An example of trajectory optimization...
A method of improving the location accuracy of a target when imaged from an unmanned aerial vehicle (UAV) is described. This method focuses on improving estimation of heading angle bias to then improve geolocation performance. A Particle Swarm Optimization (PSO) algorithm is employed to derive an expression of optimal flight path, which can be a guide for trajectory planning. The aircraft is commanded...
For an accurate and precise periodic scanning motion of a galvanometer scanner, this paper presents iterative learning control (ILC) that is designed and implemented in the frequency domain to compensate for system nonlinearities, such as static friction. For a case that system identification in advance is difficult due to the nonlinearities, the frequency-domain ILC itself incorporates and performs...
Widespread application of real-time, Nonlinear Model Predictive Control (NMPC) algorithms to systems of large scale or with fast dynamics is challenged by the high associated computational cost, in particular in presence of long prediction horizons. In this paper, a fast NMPC strategy to reduce the on-line computational cost is proposed. A Curvature-based Measure of Nonlinearity (CMoN) of the system...
A guidance problem with the impact time constraint is considered under nonlinear kinematics. The guidance design makes the range to the stationary target behave as a quartic polynomial in time. The analytical availability of the polynomial coefficients provides a feasible basis. Additionally, another important feature of the proposed impact time guidance law is that it does not rely on a time to go...
Indoor localization techniques proposed to date have assumed costly resources in terms of computation, power, or sensing modality for many wearable end-devices in the Internet of .ings (IoT). To make localization a universal feature for IoT devices, we propose EcoLoc, an indoor localization system using collaborative version of Conditional Random Fields (CCRF) integrated with our encounter model to...
Short-range wireless positioning and inertial measurement unit (IMU) have been widely used in indoor positioning systems. However, wireless signals fluctuate seriously and the accuracy of low-cost IMU system suffers from gyroscope drift, magnetic interference and accumulative error. In this paper, we propose a fusion positioning system based on Wireless signal, Map information and Inertial sensors,...
Fully autonomous landing on moving platforms poses a problem of importance for Unmanned Aerial Vehicles (UAVs). Current approaches are usually based on tracking and following the moving platform by means of several techniques, which frequently lack performance in real applications. The aim of this paper is to prove a simple landing strategy is able to provide practical results. The presented approach...
In this paper, non-linear estimators and feed-forward actions are designed to solve a vehicular platoon control problem. In particular, these estimators are useful in implementation of a Multi-Layer Consensus Seeking approach to the platooning problem. In the Multi-Layer approach the feed-forward part is built separately from the feedback part, based on desired trajectories. This opens the way to...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.