This paper explores a novel design of utilizing Leader following multi-agent system (MAS) consensus algorithm with Field Oriented Control (FOC), induction motors using a Hybrid control scheme containing regulation, po...
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In this article, a unique and innovative design for addressing the speed synchronization problem in a multi-motor system using Brush less DC (BLDC), motors is presented by utilizing motor back emf equation and rotor p...
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When measuring the surface subsidence of unstable areas such as railroad beds and large construction fields, it is not practical to always find stable positions to install measurement instruments. Yet installing those...
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When measuring the surface subsidence of unstable areas such as railroad beds and large construction fields, it is not practical to always find stable positions to install measurement instruments. Yet installing those instruments in unstable positions will cause measurement errors or even the complete failure of long-term subsidence surveillance. In this paper, the innovative concept and its method of "displacement-relay videometrics" are proposed. With the method, a double-headed camera is designed, and two constraints, the "fixation constraint" and the "homologous constraint", are established to construct the displacement-relay measurement equations, which can concurrently give the subsidence of the points to be measured and the positions where the cameras are fixed. The method and its measurement system are thus capable of automatically measuring the surface subsidence under the condition that the cameras are mounted on unstable locations over long durations. Therefore, the method has the broad prospect of undertaking automatic, long-term and continuous measurement for surface subsidence in engineering projects such as railroad beds, bridges and the ground beds of tall buildings. The proposed method opens a new area that cameras can be mounted on unstable platform to make high accuracy measurements, which is of great significance for applications.
Honeycomb structure infilling is an important way to achieve lightweight. Focusing on the deficiency of the non-optimized macro-material distribution in uniform honeycomb structures, a modeling method of non-uniform h...
Honeycomb structure infilling is an important way to achieve lightweight. Focusing on the deficiency of the non-optimized macro-material distribution in uniform honeycomb structures, a modeling method of non-uniform honeycomb structures based on topology optimization was proposed. The loaded component was topology-optimized and the density results were mapped to the relative density matrix of cells. The rapid and automatic modeling of non-uniform honeycomb structures was realized with the using of User-Defined Features and the cyclic definitions of the reference datums. The simulation results show that the mechanic performance of non-uniform honeycomb structures is better than uniform honeycomb structures and the efficiency of the proposed method is validated.
Lattice material infilling is an important way to achieve lightweight. Focusing on the problems of non-uniform arrangement and the finite element analysis (FEA) of lattice material in the parts, a lightweight design m...
Lattice material infilling is an important way to achieve lightweight. Focusing on the problems of non-uniform arrangement and the finite element analysis (FEA) of lattice material in the parts, a lightweight design method based on lattice material is proposed with the spacecraft servo frame as the design object. Modal analysis and topology optimization are carried out according to the boundary conditions. The optimized density results are used to guide the design of lattice material parameters and arrangement. The equivalent mechanical properties of lattice material are obtained through the standard specimens experiments. The equivalent material FEA model of the lightweight servo frame is established, and the performance of the lightweight structure is tested by FEA simulation and experiment. The results show that under the impact condition, the lightweight servo frame meets the performance requirements and the simulation method through the equivalent material model is validated.
Recent advances in modeling and control of crowd of pedestrians are briefly surveyed in this paper. Possibilities of applying fractional calculus in the modeling of crowd of pedestrians have been shortly reviewed and ...
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The failure mechanism of rubber materials under accelerated stress in aging process may be different from that under normal conditions. Therefore,identification of the failure mechanism consistency is necessary for th...
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The failure mechanism of rubber materials under accelerated stress in aging process may be different from that under normal conditions. Therefore,identification of the failure mechanism consistency is necessary for the accelerated aging testing of rubber material. To solve the problem, we study the relationship between the aging velocity of permanent compression set value and aging time. Firstly, according to the relationship, the aging velocity constant is obtained through the least square method. Then, combining with the aging velocity constant, we found that the activation energy is equal to the slope of linear function about Arrhenius model. Based on that failure activation energy keeps same under same failure mechanism, an identification method about failure mechanism consistency is developed. Finally, to demonstrate and validate the proposed method, we take the accelerated aging testing for the nitrile rubber-26 sealing gasket as an example.
Aiming at the feature selection for the fault prognosis in the planetary gear set of helicopter main transmission system,a methodology based on the dynamical model with fault seeded was presented to generate run-to-fa...
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Aiming at the feature selection for the fault prognosis in the planetary gear set of helicopter main transmission system,a methodology based on the dynamical model with fault seeded was presented to generate run-to-fail data,and then some statistical algorithms were used to evaluate the feature *** to the research,the dynamical model of a planetary gear set with fault seeded was developed,and then run-to-fail data could be obtained from the simulation results of the *** all,the feature parameters suitable for fault prediction were evaluated by some statistical algorithms.
In this paper, we demonstrate an ultra-sensitive photon sensor based on a membrane mechanical resonator for the first time, which consists of free-standing one-particle-thick super-lattice sheet of self-assembled nano...
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ISBN:
(纸本)9781509006090
In this paper, we demonstrate an ultra-sensitive photon sensor based on a membrane mechanical resonator for the first time, which consists of free-standing one-particle-thick super-lattice sheet of self-assembled nano-particles. Because of plasmon resonance, the membrane resonator has very strong light-matter interaction, which converts photos to heat at very high efficiency. Also, the organic-inorganic hybrid nature of the membrane owns an extremely photon-sensitive stiffness. Experimental results indicate that only under a low optical radiation power of 15 mW/cm~2, the resonator shows an obvious frequency shift of 40% (from 55.2 to 34.1 kHz), which is around two or three orders of magnitude higher than that for conventional mechanical resonators.
An adaptive non-homogeneous higher order sliding mode control (HOSMC) method for a class of uncertain nonlinear systems is proposed in this paper. The HOSMC problem can be viewed as the finite time stabilization of a ...
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