Publications by authors named "Baihai Zhang"

4 Publications

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Adaptive filtering for MEMS gyroscope with dynamic noise model.

ISA Trans 2020 Jun 1;101:430-441. Epub 2020 Feb 1.

School of Automation, Beijing Institute of Technology, Beijing, 100081, China. Electronic address:

MEMS (Micro-Electro-Mechanical Systems) gyroscope is the core component in the posture recognition and assistant positioning, of which the complex noise limits its performance. It is essential to filter the noise and obtain the true value of the measurements. Then an adaptive filtering method was proposed. Firstly, noises of MEMS gyroscope were analyzed to build the basic framework of the dynamic noise model. Secondly, the dynamic Allan variance was improved with a novel truncation window based on the entropy features, which referred to the parameters in the noise model. Thirdly, the adaptive Kalman filter was derived from the dynamic noise model. Finally, the simulation and experiment were carried out to verify the method. The results prove that the improved dynamic Allan variance can extract noise feature distinctly, and the filtering precision in the new method is relatively high.
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http://dx.doi.org/10.1016/j.isatra.2020.01.030DOI Listing
June 2020

Research about DoS Attack against ICPS.

Sensors (Basel) 2019 Mar 29;19(7). Epub 2019 Mar 29.

School of Automation, Beijing Institute of Technology, Beijing 100081, China.

This paper studies denial-of-services (DoS) attacks against industrial cyber-physical systems (ICPSs) for which we built a proper ICPS model and attack model. According to the impact of different attack rates on systems, instead of directly studying the time delay caused by the attacks some security zones are identified, which display how a DoS attack destroys the stable status of the ICPS. Research on security zone division is consistent with the fact that ICPSs' communication devices actually have some capacity for large network traffic. The research on DoS attacks' impacts on ICPSs by studying their operation conditions in different security zones is simplified further. Then, a detection method and a mimicry security switch strategy are proposed to defend against malicious DoS attacks and bring the ICPS under attack back to normal. Lastly, practical implementation experiments have been carried out to illustrate the effectiveness and efficiency of the method we propose.
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http://dx.doi.org/10.3390/s19071542DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6479565PMC
March 2019

An adaptive image enhancement method for a recirculating aquaculture system.

Sci Rep 2017 07 24;7(1):6243. Epub 2017 Jul 24.

Beijing Research Center for Information Technology in Agriculture, Beijing, 100097, China.

Due to the low and uneven illumination that is typical of a recirculating aquaculture system (RAS), visible and near infrared (NIR) images collected from RASs always have low brightness and contrast. To resolve this issue, this paper proposes an image enhancement method based on the Multi-Scale Retinex (MSR) algorithm and a greyscale nonlinear transformation. First, the images are processed using the MSR algorithm to eliminate the influence of low and uneven illumination. Then, the normalized incomplete Beta function is used to perform a greyscale nonlinear transformation. The function's optimal parameters (α and β) are automatically selected by the particle swarm optimization (PSO) algorithm based on an image contrast measurement function. This adaptive image enhancement method is compared with other classic enhancement methods. The results show that the proposed method greatly improves the image contrast and highlights dark areas, which is helpful during further analysis of these images.
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http://dx.doi.org/10.1038/s41598-017-06538-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5524723PMC
July 2017

Stability of a Class of Multiagent Tracking Systems With Unstable Subsystems.

IEEE Trans Cybern 2017 Aug 30;47(8):2193-2202. Epub 2016 Jun 30.

In this paper, we predeploy a large number of smart agents to monitor an area of interest. This area could be divided into many Voronoi cells by using the knowledge of Voronoi diagram and every Voronoi site agent is responsible for monitoring and tracking the target in its cell. Then, a cooperative relay tracking strategy is proposed such that during the tracking process, when a target enters a new Voronoi cell, this event triggers the switching of both tracking agents and communication topology. This is significantly different from the traditional switching topologies. In addition, during the tracking process, the topology and tracking agents switch, which may lead the tracking system to be stable or unstable. The system switches either among consecutive stable subsystems and consecutive unstable subsystems or between stable and unstable subsystems. The objective of this paper is to design a tracking strategy guaranteeing overall successful tracking despite the existence of unstable subsystems. We also address extended discussions on the case where the dynamics of agents are subject to disturbances and the disturbance attenuation level is achieved. Finally, the proposed tracking strategy is verified by a set of simulations.
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http://dx.doi.org/10.1109/TCYB.2016.2581830DOI Listing
August 2017