Papers by Author: Cheng Dong Wu

Abstract: The existing object tracking method using covariance modeling is hard to reach the desired tracking performance when the deformation of moving target and illumination changes are drastic, we proposed a object tracking algorithm based on bilateral filtering. Firstly, the algorithm deals the image to be tracked with bilateral filtering, and extracts the needed features of filtered image to construct covariance matrix as tracking model. Secondly, under log-Euclidean Riemannian metric, we construct similarity measure for object covariance matrix and model updating strategy. Extensive experiments show that the proposed method has better adaptability for object deformation and illumination changes.

Abstract: Considering the process of objects imaging in the camera is essentially the projection transformation process. The paper proposes a novel visual tracking method using particle filtering on SL(3) group to predict the changes of the target area boundaries of next moment, which is used for dynamic model. Meanwhile, covariance matrices are applied for observation model. Extensive experiments prove that the proposed method can realize stable and accurate tracking for object with significant geometric deformation, even for nonrigid objects.

Abstract: In order to obtain the actual characteristics of horizontal atmospheric diffusion direction, based on Gauss plume model and the measured data, we use BP neural network to fit the characteristic curve of the diffusion coefficient. We establish a BP neural network, and then we train the network and simulate the diffusion coefficient. According to the simulation results, we compare the characteristic curve with the curve based on the least square method. And the results show that the characteristic curve based on BP neural network has better fitting accuracy. Hence, using the trained neural network to predict the diffusion coefficient has certain theory meaning and actual application value.

Abstract: In wireless sensor networks, NLOS propagation often enlarges the errors of position estimates when time-of-arrival (TOA) measurements are used. To mitigate the effects caused by NLOS propagation, herein, an EKF-based robust non-parametric approach is proposed. In this paper, we utilize the variable kernel method to obtain an approximate noise density function, which is inexpensively computational and then used to improve the mobile positioning accuracy. Note that the standard EKF often works well when NLOS error is adequately low. This property could also be used to improve the accuracy of mobile positioning. In the proposed algorithm, a hard decision is employed to choose the rational position estimate which may come from the non-parametric approach or the standard EKF. Numerical simulations show a significant improvement over the standard EKF.

Abstract: This paper describes an efficient Bayesian framework for localization based on Ultra-wide Bandwidth (UWB) system. Approximate grid-based method based on the Hidden Markov Model (HMM) is an effective method to estimate the position of the Moving Terminal (MT) with the mixed line-of-sight/non-line-of-sight (LOS/NLOS) situation. This article proposes an algorithm by modifying the Position Transition Probability (PTP) according to the practical dynamic model and uses the information fusion effectively. We compare the Maximum Likelihood (ML) estimation with Detection/Tracking Algorithm (D/TA) estimation and its improved algorithm by simulation, in which the localization to an identical trajectory has been tested. The results of the analysis show that the proposed method has better accuracy and stability.

Abstract: To satisfy the requirement of the control parameters in greenhouse, this paper introduced the design scheme of monitoring and control system based on Zigbee due to its low-cost, simplicity and mobility. We designed the sensor node, control node and gateway node based on CC2430, described the design method of hardware circuit and the flow chart of software. By monitoring the environment factors in real time, such as illumination, temperature, humility and carbon dioxide, the spray system, ventilation fans and lighting lamps were automated controlled to satisfy crop growth requirement. The monitoring system is easy to expand and update, and the program interface is friendly to operate.

Abstract: The robot joints are usually rotational axis by two link joints, bionic features is not strong. The shortcomings of intelligent MR damper control multi-axis bionic knee can only provide resistance and certain sizes of regain momentum, cannot provide larger power, therefore this paper gives by the multi-axis four-bar structure, ball screw transmission hybrid drive multiaxial bionic active knee institutions. And analysis the human leg institutions and commonly used two-bar structure, solve the ball screw transmission installation location parameters. And established based on hybrid drive of the bionic active the knee's virtual prototype.

Abstract: This paper proposed a preprocessing method of SWCNTs dispersion based on rinsing technology. With the assistance of SDS, SC and SDBS, this method adopted the ultrasonication oscillation technology to solve the problem of SWCNTs dispersion. In addition, it compared the effect of the three kinds of surfactants on SWCNTs dispersion under the same conditions. And AFM was applied in this experiment to scan and image the samples. The results showed that the solubility and adsorption efficiency of the surfactants had influence on the SWCNTs dispersion quality. Furthermore, the paper primarily and theoretically modeled and analyzed the experiment results from the aspect of the surfactants' hydrophilic and lipophilic structure.

Abstract: Passive AKPs being currently in use do not respond to the needs of daily living activities of many amputees. For example, it is difficult to climb stairs with natural posture and to adjust the stiffness of the knee joint motion during the swing phase. Therefore this paper proposes the instantaneous center with variable rotating multiaxial knee, the multiaxial four league rod mechanism composition, have bionic similarity, involving active knee mechanism design and experiment. Artificial limb main part is through motor based on active control knee flexion knee actuator.This paper was designed by the ball screw electric a new initiative knee institutions.