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Permanent magnet synchronous motors are the core components of electric vehicles and widely used in the field of electric vehicles. The existence of vibration will reduce the operating efficiency and service life of the motor, which is the key factor to determine whether the motor is running normally. In this article, a certain type of permanent magnet synchronous motor is taken as the test object. The permanent magnet synchronous motor is divided into three substructures: stator, rotor and shell. The finite element modal results are obtained respectively. The modal parameters of the whole PMSM are calculated by using the substructure modal synthesis method. The weak links of the motor are found out and the structure optimization is carried out. Through the calculation of the modal analysis, it can be seen that each vibration mode of the optimized motor has been reduced, and the amplitude difference between the 2nd order and the 5th order is the largest. Finally, the modal test is carried out on the motor using the exciter method, the test results are analyzed, and the modal parameters of the motor are obtained through the frequency domain analysis method, the FEA result is confirmed by the modal test of the motor.

The wave glider is widely used in marine engineering. As one of the most crucial components of the wave glider, the wing plate system significantly affects the utilisation efficiency of wav...

Compressed sensing is a novel information collection theory. Compared with the Nyquist sampling theorem, compressed sensing can obtain all the information of a signal with very few samples. The deterministic construction of the measurement matrix is an important research area in compressed sensing. Inspired by the observation that the parity-check matrix of low-density parity-check code can be used as a deterministic measurement matrix, in this paper, a special balanced incomplete block design proposed by Bose is exploited to construct the deterministic measurement matrix. The incidence matrix of the balanced incomplete block design proposed by Bose is used as the deterministic measurement matrix. The experimental results show that the proposed measurement matrix has lower mutual coherence than some widely used measurement matrices and shows better performance than the progressive edge-growth measurement matrix. Moreover, by using the embedding operation, the modified measurement matrix with a more flexible size and improved performance is constructed. In our simulation, the modified measurement matrix has lower mutual coherence and better performance than some widely used measurement matrices.

Cyber-physical systems (CPS) is a complex intelligent system consists of discrete asynchronous information and continuous synchronous physical systems that are different in structure and mathematics basis. In this article, a new simulation strategy for CPS model is explored based on the equation-based modeling language Modelica. Firstly, some new semantics, such as Clock, Sampling and Holding, are proposed to model information systems based on Modelica. Secondly, the serialization method is proposed to separate the information equation systems from CPS model and sequence the information and physical equation systems respectively. Thirdly, the unified simulation method, which consists of information system simulation strategy and unified simulation strategy, is present to solve the CPS model in a unified form. An inverted pendulum system is taken to demonstrate the above methods. Differently from the common modeling methods and simulation strategy, where the information system and physical system are modeled and simulated separately in different tools and then linked with interfaces between these tools. The major novelty of proposed strategy is that the CPS model could be built and simulated in a unified framework and the information system and physical system could be linked automatically in a natural way.

It is hot research topic to evaluate the equipment performance quickly and accurately. The performance of complex product with high reliability and long-life is indicated frequently by more than single feature variable. And it is possible that multiple degradation modes coexist due to diverse number of performance degradation modes and their correlations. Considering the effects of the different degradation processes on the system performance and the dependences between the multivariate, the system performance status can be described accurately, which then will improve the safety and maintenance efficiency of the system and reduce its life cycle cost. Based on the State-of-the-art at home and abroad, this paper presents two kinds of performance evaluation methods, one is based on leading variables and the other is hybrid variables. Especially the typical methods and several performance degradation models used in the above two evaluation processes are introduced, in order to provide academic and engineering reference for the related research.

Compared with the traditional design, modular design has the prominent agility feature in dynamic integration, integrated system control of product modular design Meta-data was analyzed in this research, and then Meta modeling process throughout product modular design Meta- data was also proposed. Based on modular design Meta-model, under the same conditions, the same instance of a modular product sequence optimization was applied with IPSO control algorithm, from several test experiments result show, IPSO control algorithm global search ability and convergence rate has been the improvement, which is a practical and effective optimization algorithm model. Particle population is smaller by using IPSO algorithm, which convergence rate has a more distinct advantage.

To solve the coupling and optimizing problems in MEMS designing and analyzing process, the paper mainly put forward to the uniform model construction simulation method. The method adopt uniform constraints to describe MEMS multi-fields simulation model, firstly construct MEMS model library which includes structure, electricity, magnetic, thermal and fluid elements in multi-field uniform language modeling; through these elements, MEMS physics simulation model can be directly constructed; after model construction, some prosperities of the MEMS devices can be simulated. The aim of the method of paper is trying to conquer the computing efficiency of numerical simulation and abstraction problems of hardware describe language (HDL) and realizes MEMS multi-fields uniform constrained model construction and solving theory system. At last, an application example of the method has been realized, which shows that the method is effective to the early design of MEMS product.

With customer and market diversification of complex customized product demand challenging to modern enterprises, the design process of product is continually confronted with various complicated design information. In this paper, the integration technology of information in the process of Multidisciplinary collaborative design (MCD) was discussed to shorten product delivery cycle, reduce overall costs and improve product quality. Firstly, a detailed description of the organization structure and modeling process of MCD-oriented Integration of Product Design Meta- model was given; secondly, the process integrated control method based on MCD-oriented Integration of Product Design Meta-model was proposed; finally, this method was validated by using application example.

Based on ANSYS, the thermal analysis on the small capacity AC contactor is put forward in this paper. After the model of contactor with 9A rated current is established, the temperature field of the contactor is simulated considering the heating and heat-dissipating calculation. The heating calculation includes the heating of electrical-magnetic system and the resistances of circuit and contact. The heat-dissipation calculation includes the inner conduction, the convection and radiation of surfaces.