The positioning accuracy of a short-haul target-locating system,the inverse-GPS(IGPS) ,was analyzed in detail. The relationship between IGPS and the positioning error was discussed. The multiplicative error minimal bo...
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The positioning accuracy of a short-haul target-locating system,the inverse-GPS(IGPS) ,was analyzed in detail. The relationship between IGPS and the positioning error was discussed. The multiplicative error minimal bound of the geometric dilution of precision (GDOP) about the four-base-station IGPS was also investigated. In order to clarify the practical implementation of IGPS,the multiplicative and additive error factors which affect the positioning accuracy and theoretical estimation of positioning accuracy were presented. By analyzing the experiments of locating a target's position in virtual three-dimensional areas,the positioning performance of IGPS was illustrated. The results show that the multiplicative and additive error factors should be eliminated in IGPS to improve the positioning accuracy.
Distributed stereoscopic rotating formation control of networks of second-order agents is investigated. A distributed control protocol is proposed to enable all agents to form a stereoscopic formation and surround a c...
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Distributed stereoscopic rotating formation control of networks of second-order agents is investigated. A distributed control protocol is proposed to enable all agents to form a stereoscopic formation and surround a common axis. Due to the existence of the rotating mode, the desired relative position between every two agents is time-varying, and a Lyapunov-based approach is employed to solve the rotating formation control problem. Finally, simulation results are provided to illustrate the effectiveness of the theoretical results.
To address the issue of premature convergence and slow convergence rate in three-dimensional (3D) route planning of unmanned aerial vehicle (UAV) low-altitude penetration,a novel route planning method was *** and fore...
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To address the issue of premature convergence and slow convergence rate in three-dimensional (3D) route planning of unmanned aerial vehicle (UAV) low-altitude penetration,a novel route planning method was *** and foremost,a coevolutionary multi-agent genetic algorithm (CE-MAGA) was formed by introducing coevolutionary mechanism to multi-agent genetic algorithm (MAGA),an efficient global optimization algorithm.A dynamic route representation form was also adopted to improve the flight route ***,an efficient constraint handling method was used to simplify the treatment of multi-constraint and reduce the time-cost of planning *** and corresponding analysis show that the planning results of CE-MAGA have better performance on terrain following,terrain avoidance,threat avoidance (TF/TA2) and lower route costs than other existing *** addition,feasible flight routes can be acquired within 2 s,and the convergence rate of the whole evolutionary process is very fast.
This study aims to investigate the problem of attitude control for a spacecraft with inertial uncertainties, external disturbances, and communication restrictions. An event-triggered active disturbance rejection contr...
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This study aims to investigate the problem of attitude control for a spacecraft with inertial uncertainties, external disturbances, and communication restrictions. An event-triggered active disturbance rejection control approach is proposed for attitude tracking of the spacecraft. An event-triggered mechanism is introduced together with an extended state observer to jointly monitor the systemstates and total disturbances. The observation error is proved to be uniformly bounded. Based on the proposed control scheme,the integrated tracking system is shown to be asymptotically stable, implying successful attitude tracking of the spacecraft for the desired motion. Numerical results illustrate the effectiveness of the control strategy in achieving satisfactory tracking performance with a reduced data-transmission cost.
In this work,an event-triggered adaptive robust controller(ET-ARC) design is considered for a continuous-time nonlinear system combined with structural uncertainties and parameter *** the event-trigger scheme,the co...
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ISBN:
(纸本)9781538629185
In this work,an event-triggered adaptive robust controller(ET-ARC) design is considered for a continuous-time nonlinear system combined with structural uncertainties and parameter *** the event-trigger scheme,the controller only can obtain the sampled date of the output measurement at some certain instants determined by the designed triggering condition and therefore the performance of the ET-ARC depends on the triggering condition ***,in this work,for the adaptive robust control scheme,an event-triggered transmission strategy is proposed,which relies on the output measurement of the nonlinear ***,based on this strategy,the design idea of the adaptive robust controller is presented such that the tracking performance is ***,based on a more general assumption,we provide a possible formation of control signal which satisfies the requirement proposed.
The computation of stereo depth is a very important field of computer vision. Aiming at solving the problem of low accuracy of traditional Census-based stereo matching algorithm, a variable support-weight approach for...
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ISBN:
(纸本)9781467321969
The computation of stereo depth is a very important field of computer vision. Aiming at solving the problem of low accuracy of traditional Census-based stereo matching algorithm, a variable support-weight approach for visual correspondence search based on modified Census transform is proposed in this paper. On the basis of analyzing defects of the traditional Census transform, a modified Census transform algorithm using average value of minimum evenness sub-area as a reference instead of the center pixel intensity as a reference is raised which enhances robustness of the algorithm. The matching accuracy is improved by weighting the average value and the standard deviation of Hamming distances in a block. The experiment results indicate that the proposed approach works better than traditional ones. Accurate disparities can be obtained even in the depth discontinuities regions.
Template matching is one of the most important techniques in computer vision,where the algorithm should find the location of template image in scene *** commonly used method of template matching is Normalized Cross Co...
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ISBN:
(纸本)9781509046584
Template matching is one of the most important techniques in computer vision,where the algorithm should find the location of template image in scene *** commonly used method of template matching is Normalized Cross Correlation which has a high matching accuracy while consuming a large amount of computational *** this paper,a novel,fast and robust template matching approach is *** new algorithm randomly visits the pixels and locates local maxima by gradually moving to the regions with larger NCC *** further improve the speed and accuracy of the algorithm,several additional rules are *** analysis and experimental results show that the proposed algorithm maintain a high matching accuracy while providing a significant speedup.
A robust recursive least-squares(RLS) adaptive filter against impulsive noise is proposed for the situation of an unknown desired *** minimizing a saturable nonlinear constrained unsupervised cost function instead of ...
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A robust recursive least-squares(RLS) adaptive filter against impulsive noise is proposed for the situation of an unknown desired *** minimizing a saturable nonlinear constrained unsupervised cost function instead of the conventional least-squares function,a possible impulse-corrupted signal is prevented from entering the filter’s weight updating ***,a multi-step adaptive filter is devised to reconstruct the observed "impulse-free" noisy sequence,and whenever impulsive noise is detected,the impulse contaminated samples are replaced by predictive *** on simulation and experimental results,the proposed unsupervised robust recursive least-square adaptive filter performs as well as conventional RLS filters in "impulse-free" circumstances,and is effective in restricting large disturbances such as impulsive noise when the RLS and the more recent unsupervised adaptive filter fails.
Odometry is a very popular research direction in recent decades and plays a very critical role in the autonomous navigation ***02,as a relatively robust and mature visual odometry algorithm,becomes unreliable when dis...
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ISBN:
(纸本)9781538629185
Odometry is a very popular research direction in recent decades and plays a very critical role in the autonomous navigation ***02,as a relatively robust and mature visual odometry algorithm,becomes unreliable when distinct visual features are insufficiently or when the texture of the environment is *** if not in such a challenging environment,the drift is still a big problem for the practical ***,a lidar odometry algorithm,has been leading the way for the performance on KITTI data *** fact,it also has limitations in shape features not prominent environment,like a highway with few buildings *** that the current mobile unmanned platforms(e.g.,unmanned vehicles) are almost equipped with both lidar and cameras,this paper proposes a loose coupling visual-lidar odometry by combining VIS02 and LOAM to achieve the advantages of both camera and lidar and reduce the number of restricted *** algorithm proposed in this paper is tested on the raw data set of *** average translation error is about 1.37% on 10 sequences,and the accuracy is improved with respect to LOAM with the same *** the help of VIS02,the algorithm also performs well in shape features not prominent environment(e.g.,highway),and from the experiment results,we confirmed the efficient strategy to combine VIS02 and LOAM to adapt to challenging environment and to keep the accuracy of the algorithm.
Obstacle information detection is a prerequisite for safety and stability driving of unmanned platforms in the unknown *** detection of the obstacle using the 3D laser radar(3D LADAR) and camera is proposed in this **...
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ISBN:
(纸本)9781538629185
Obstacle information detection is a prerequisite for safety and stability driving of unmanned platforms in the unknown *** detection of the obstacle using the 3D laser radar(3D LADAR) and camera is proposed in this ***,joint calibration between 3D LADAR and camera based on the planar feature method is ***,laser point cloud is clustered to identify the number of obstacles,and then detected image is divided into the corresponding small regions according to the number of ***,we use the image processing technology to detect the obstacle *** experiments in the real world are implemented to show that the proposed approach can effectively detect the size of the obstacles.
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