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.
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.
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.
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.
Scale space generation is a fundamental problem in almost all feature extraction algorithms. Often, it is a critical prior step of most image/video analytic applications that are based on the invariance or co-invarian...
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ISBN:
(纸本)9781467374439
Scale space generation is a fundamental problem in almost all feature extraction algorithms. Often, it is a critical prior step of most image/video analytic applications that are based on the invariance or co-invariance of local features, such as SIFT based recognition, matching, and tracking applications. However, it is still quite a challenging problem to enable real-time applications of the extraction of local features due to the fact that scale space generation has a rather large computational complexity. This paper proposes the optimal FPGA design for acceleration of scale space generation. First, in order to derive the mathematical model for scale space generation that fits best in with the FPGA, we have discarded the conventional template convolution based Gaussian filtering scheme and adopted a novel IIR filter based recursive Gaussian blurring algorithm. Then, an approach based on the Retiming technique, which could find the minimal operational period for any given IIR filter, is used to finalize the overall design. For 1024×768 video, the proposed design is able to generate scale spaces at almost 400 fps, which is fast enough to support most real-time applications like object recognition, object matching, and 3D reconstruction.
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.
Electro-hydraulic servo systems(EHSSs) have been widely used in industrial and military applications for their high power-to-size ratio and the ability to supply huge ***,precise control of EHSSs cannot be easily obta...
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ISBN:
(纸本)9781479900305
Electro-hydraulic servo systems(EHSSs) have been widely used in industrial and military applications for their high power-to-size ratio and the ability to supply huge ***,precise control of EHSSs cannot be easily obtained due to their inner nonlinearity and parameter *** load is another factor to decrease the tracking performance of *** adaptive robust control(IARC) was proposed to improve the tracking performance of EHSS,but due to the poor parameter adapting speed,IARC can be further improved to have better *** projection type parameter estimation algorithm is redesigned to increase the adapting speed when parameter is changed.A fast adaptive robust control (FARC) is then proposed to speed up the parameter adapting speed,so that a better tracking performance of FARC is maintained. Simulation results show that the proposed FARC gives an improved tracking performance and a faster parameter adaptation.
This paper considers the distributed attitude synchronization problem for multiple spacecraft with external disturbances. Distributed discontinuous adaptive controller is designed based on the relative attitudes and a...
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ISBN:
(纸本)9781467355322
This paper considers the distributed attitude synchronization problem for multiple spacecraft with external disturbances. Distributed discontinuous adaptive controller is designed based on the relative attitudes and angular velocities of neighboring spacecraft and attitude synchronization can be reached for any communication graph containing a directed spanning tree. To tackle the chattering effect caused by the discontinuous controller, a continuous controller is further proposed, under which both the synchronization errors and the adaptive gains are ultimately bounded. Extensions to the case with a leader-follower communication graph with the leader as the spanning tree's root are further studied.
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