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The phenomenon occasionally occurs during the running of the high-speed maglev train that the suspension control system fail to get the gap signal. That's because one of the two suspension sensors mounted on the side of the lap structure becomes invalid and the other is just over the joint. The high-speed maglev train will not be able to track desired trajectory consequently. This study is conducted...
In order to achieve the unified measurement of the air velocity from subsonic to supersonic circumstance, an analytical method referred to as the equivalent acoustic source, which was only suitable for the analysis of supersonic air current before, is extended to the subsonic case. Systematic analysis demonstrates the essential difference of the air current property between subsonic and supersonic...
In order to analyze the influence of rigid foot's geometry shape of legged robot on the sinking process in soft soil, MAT 147 material is used as the constitutive model of soil and the dynamic simulation of rigid foot's sinking process is carried out with Multi Material Arbitrary Lagrangian Eulerian(MM-ALE) method. The plate sinking test is simulated with MM-ALE method and the results are compared...
For suspension control of low-speed PEMS train, the usual strategy is to separate the maglev module into two individual single points, which neglects the coupling effect of adjacent single point. To suppress the coupling effect, this paper suggests the method of designing control law considering the whole module. The simulation result verifies the validity of the new control law, which can suppress...
Currently, computer is widely used in a ground vehicle or at the aircraft. However, the vibration maybe impact on the computer, especially the HD array. Therefore, this paper presents a new mechanical and electromagnetic composite vibration isolation system, adding active electromagnetic vibration isolation devices on the foundation of passive mechanical vibration isolation system. Symmetric electromagnets...
Crawler robot has been used widely in many areas because of its excellent adaptation for all kinds of complex terrain. As one of automatic control methods for the trajectory trace of robot, sliding mode control has advantages over others because of its non-sensitivity and capability of quick response when the system parameters change, it will be used in this paper for the trace of trajectory. To begin...
City-scale human mobility analysis is an important problem in pervasive computing. In this paper, with qualitative and quantitative analysis, we establish and confirm the relationship between the get-on/off characteristics of taxi passengers and the social function of city regions. We find that get-on/off amount in a region can depict the social activity dynamics in that area, i.e. the temporal variation...
Colored Petri Net(CPN) approach is powerful for modeling and analysis of command and control (C2) problems through synchronous and asynchronous processing activities and properly encapsulates hierarchical behavior. We give an informal introduction to the basic concepts and ideas of CPN. A CPN implementation of a aerial defense model being used for representing the real-time aspects and behavior of...
Time delay is a kind of common nonlinearity, which is consisted in many parts of suspension system of high speed maglev train.In this paper, the dynamic behavior of suspension system of maglev train with time-delayed velocity and acceleration feedback signal is considered with rigid guideway. Taking time delay as its bifurcation parameter, the condition with which the Hopf bifurcation may occur is...
The problem of sensor-fault detection and diagnosis (FDD) of maglev system was studied based on principal component analysis (PCA). First, the mathematic model of single electromagnet suspension system was constructed, and then a sensor-FDD strategy was designed for it based on PCA. The performance of the FDD strategy was simulated. At last, tracking-differentiator (TD) was introduced into the sensor-FDD...
Objective To systematically analyze and summarize non-thyrogenous masses of the neck (NTMN) by consideration of new areas, a large sample size and multiple-aspect analysis. Methods Our research involved 3125 NTMN cases. We summarized the proportion of various NTMN and the distribution of the neck diseases based on the new international classification. The clinical traits such as sexual proportion...
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