Variable Winding Analysis and Optimization of Dual-mode Starter-Generator for Micro HEV Applications

Xiao Dong,Shi Liwei,An Junhao,Xing Fuzhen 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

To satisfy the requirement of high torque in starting state and accurate voltage regulation in generating state, a Dual-Mode Starter Generator (DMSG) with variable winding is proposed in this paper. Firstly, the influence of winding parameters on the performance of DMSG is analyzed by establishing the mathematical model of equivalent turns. Next, the cause of circulating current in starting state is analyzed. In order to solve the problem of circulating current between parallel branches, this paper presents a method that adding directional diode in main power circuit. The correctness of this method is verified by simulation. Then, the optimal matching relationship between the field winding and armature winding with multi-objective optimization is determined. At last, the FEA and prototype experiments verify the feasibility and performance of starter mode and generator mode of the DMSG.

The Research of Adaptive Sliding Mode Controller for Motor Servo System Using Fuzzy Upper Bound on Disturbances

Xiaodong Liu,Yunjie Wu,Baiting Liu 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.5

Considering sliding mode control (SMC) method using the estimation of upper bound on disturbances in motor servo system, if the upper bound is underestimated, the position tracking precision is poor. Contrarily, the control input is overlarge and even chatters violently. To solve the above problems, an adaptive sliding mode controller (ASMC) is proposed. It utilizes a fuzzy decision maker (FDM), which exports the estimation of upper bound on disturbances according to the information of position tracking error and control input. The computer simulations on a dc motor present that the proposed method guarantees satisfactory position tracking accuracy and the chattering at control input is evidently suppressed. Moreover, the output of FDM is sensitive to the changes of disturbances real-timely and precisely. Subsequently, the proposed scheme possesses strong robust performance against disturbances in motor servo system.

Stereo Video Transmission Distortion Derived Algorithm Based On Data Partitioning In H.264/AVC

Xiaodong Wang,Jiao Ke,Hanzhang Wang,Lianjun Zhang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.8

H.264/AVC coding standard slices the encoded Data using the Data Partitioning (DP) based on syntax priority to improve the error resistance for H.264 bit stream. According to this feature, considering the temporal and spatial correlation in stereoscopic video, network performance and terminal error concealment technology. A derived algorithm for determining the transmission distortion based on different DP parts in a Group-of-Pictures (GoP) is proposed. The algorithm takes both the distortion introduced by error diffusion and error concealment into account, which can be estimated by the stereo video quality at encode side under the condition of the specific network. Experimental results show that the algorithm used to calculate the distortion basically coincided with simulation results, and the algorithm can be applied to different sequences with various movement characteristics.

Cascade Network Based Bolt Inspection In High-Speed Train

( Xiaodong Gu ),( Ji Ding ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.10

The detection of bolts is an important task in high-speed train inspection systems, and it is frequently performed to ensure the safety of trains. The difficulty of the vision-based bolt inspection system lies in small sample defect detection, which makes the end-to-end network ineffective. In this paper, the problem is resolved in two stages, which includes the detection network and cascaded classification networks. For small bolt detection, all bolts including defective bolts and normal bolts are put together for conducting annotation training, a new loss function and a new boundingbox selection based on the smallest axis-aligned convex set are proposed. These allow YOLOv3 network to obtain the accurate position and bounding box of the various bolts. The average precision has been greatly improved on PASCAL VOC, MS COCO and actual data set. After that, the Siamese network is employed for estimating the status of the bolts. Using the convolutional Siamese network, we are able to get strong results on few-shot classification. Extensive experiments and comparisons on actual data set show that the system outperforms state-of-the-art algorithms in bolt inspection.

Behaviors of Wall and Ground due to T-shaped Excavation

Xiaodong Zhao,Guoqing Zhou,Laijun Qiao,Yangguang Chen 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.5

Extensive monitoring was performed on a T-shaped site with a length of 280 m, a width of 16 m, and a maximal depth of 20.4 m. The braced excavation was performed under retaining comprised of cast-in-situ bored piles and jet grouting piles. The field databased wall performance and its influences to ground were assessed by detailed comparisons with that in other excavations. It is showed that the wall deflections, ground movements and bracing forces all exhibited a typical camelback-shaped characteristic along the length direction, and a maximum 100% reduction of which was observed due to the jet grouting. The rebar near sections with varied excavation depths was in a tension state both on the excavation and the retained sides due to the twodimensional unbalanced force, and the corresponding bracing force was small. The maximum wall deflection δhm decreased asthe partitioning excavation moved horizontally, and it was less than 0.04% of the final horizontal excavation length Le. The normalized Fσmax approximately approached to be identical with the normalized Fbmax, while most of the occurring depths for Fσmax were greater than that for Fbmax.

Effect of Aspirin on the Expression of Hepatocyte NF-κB and Serum TNF-α in Streptozotocin-Induced Type 2 Diabetic Rats

Xiaodong Sun,Fang Han,Junling Yi,Lina Han,Ben Wang 대한의학회 2011 Journal of Korean medical science Vol.26 No.6

Aspirin is a kind of anti-inflammatory drug and may be used to reverse hyperglycemia,hyperinsulinemia, and dyslipidemia by improving insulin resistance. We hypothesized that aspirin improves insulin resistance in type 2 diabetes by inhibiting hepatic nuclear factor kappa-β (NF-κB) activation and serum tumor necrosis factor-α (TNF-α). Adult male Wistar rats were randomly divided into four groups: control, untreated diabetic, diabetic treated with metformin (100 mg /kg/day), and diabetic treated with aspirin (120 mg/kg/day). Diabetes was induced by high-fat feeding and a low dose of streptozotocin (30 mg/kg). After treatment, plasma glucose, insulin, lipids, free fatty acids (FFAs) concentrations and serum TNF-α were determined. The expression of NF-κB in hepatocytes was analyzed by immunohistochemistry and western blot. The results showed administration of aspirin caused no significant lowering in fasting glucose level but significant reduction of hepatic NF-κB expression and serum TNF-α level with improved insulin resistance compared to the diabetic group. The relevant analysis showed positive correlation between the expression of homeostasis model assessment-insulin resistance (HOMA-IR) and NF-κB (r = 0.799, P <0.01); HOMA-IR and serum TNF-α (r = 0.790, P < 0.01). It is concluded that aspirin improves insulin resistance by inhibiting hepatic NF-κB activation and TNF-α level in streptozotocin-induced type 2 diabetic rats.

Notes on the biomass expansion factors of Quercus mongolica and Quercus variabilis forests in Korea

Xiaodong Li,이명종,손영모,이경학,김래현,손요환 한국생태학회 2012 Journal of Ecology and Environment Vol.35 No.3

Biomass expansion factors, which convert timber volume (or dry weight) to biomass, are used for estimating the forest biomass and accounting for the carbon budget at a regional or national scale. We estimated the biomass conversion and expansion factors (BCEF), biomass expansion factors (BEF), root to shoot ratio (R), and ecosystem biomass expansion factor (EBEF) for Quercus mongolica Fisch. and Quercus variabilis Bl. forests based on publications in Korea. The mean BCEF, BEF, and R for Q. mongolica was 1.0383 Mg/m3 (N = 27; standard deviation [SD], 0.5515), 1.3572 (N = 27; SD,0.1355), and 0.2017 (N = 32; SD, 0.0447), respectively. The mean BCEF, BEF, and R for Q. variabilis was 0.7164 Mg/m3 (N = 17; SD, 0.3232), 1.2464 (N = 17; SD, 0.0823), and 0.1660 (N = 8; SD, 0.0632), respectively. The mean EBEF, as a simple method for estimating the ground vegetation biomass, was 1.0216 (N = 7; SD, 0.0232) for Q. mongolica forest ecosystems,and 1.0496 (N = 8; SD, 0.0725) for Q. variabilis forest ecosystems. The biomass expansion factor values in this study may be better estimates of forest biomass in Q. mongolica or Q. variabilis forests of Korea compared with the default values given by the Intergovernmental Panel on Climate Change (IPCC).

A Control Method to Make LQR Robust: A Planes Cluster Approaching Mode

Xiaodong Liu,Yunjie Wu,Yu Zhang,Song Xiao 제어·로봇·시스템학회 2014 International Journal of Control, Automation, and Vol.12 No.2

Linear quadratic regulator (LQR) is an optimal controller being used for linear systems, and it can minimize the comprehensive quadratic performance index (QPI) with respect to convergence error and control consumption. However, LQR lacks the robust property to cope with parameter perturbations and external disturbances. Aiming at the above deficiency of LQR, a robust LQR (RLQR) is proposed for linear systems under the guideline of planes cluster approaching mode (PCAM). In the proposed RLQR, one nonlinear item is introduced into control law, and it cooperates with the other linear item to guarantee the global asymptotic stability in the presence of equivalent disturbances. The conditions of global asymptotic stability are deduced by the method of Lyapunov function. Simulation results present that, the chosen LTI plant using RLQR possesses smaller QPI in the existence of time-varying disturbances, compared with the conventional LQR and sliding mode controller (SMC).

Spatial Prediction of Soil Variables Based on Primary Terrain Attributes in a Gentle Area

Xiaodong Song,Ganlin Zhang,Feng Liu 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Effect of SiF₄ addition on the structures of silicon films deposited at low temperature by remote plasma enhanced chemical vapor deposition

Xiaodong Li,Young-Bae Park,Dong-Hwan Kim,Shi-Woo Rhee 한국진공학회 1995 한국진공학회 학술발표회초록집 Vol.- No.-