Abstract:Based on the current research status of multiagents system control theory and technology, the paper makes a detailed overview for unmanned ground systems. From two aspects of behaviour and task cooperative control for multiagents, the relevant theory and application problem is discussed. Moreover, some existed open problems are presented and a possible future development is proposed. For unmanned ground systems, cooperative control will be of great importance in promoting social and military benefits and maximizing the executive function of ground mission.

Abstract:Based on the nonlinear governing equation of the carbon nanotubereinforced composite plate, the averaged equation under 1〖DK〗∶3 internal resonances is obtained by using the method of multiple scales. It is then simplified by means of the normal form theory. The nonlinear dynamics of the unperturbed system and the effect of the perturbation terms on the manifold are investigated. Energyphase method is used to validate the existence of the multipulse jumping orbits. It is eventually to approved that chaotic dynamics in the sense of Smale horseshoes takes place at the carbon nanotubereinforced composite plate under certain parameters. The results also provides essential data for theoretical analysis and engineering practice.

Abstract:As the gear transmission system with clearance responses in a way of abundant nonlinear dynamics, this paper establishes a dynamic model of twodegreeoffreedom gear transmission system. Firstly, the bifurcation of the gear transmission system and the chaotic dynamic behavior using the numerical method is investigated, and the nonsmooth function is then fitted with the smooth function. Moreover, nonlinear dynamic phenomenon of gear transmission system with fitted clearance function is achieved using multiscale perturbation. Eventually, the results are compared with that of nonsmooth system without numerical fitting, which also provides essential data for the future research of gear transmission system with a clearance.

Abstract:Dynamic modeling method of onorbit maneuvering of freefree slender flexible space structures was studied. In literature, a dynamic model without rigidflexible coupling terms was adopted for designing motion controller. Establishing a dynamic model with relatively accuracy is the premise of obtaining a welldesigned motion controller, therefore, it is necessary to establish the coupling model and find the difference between them. A floating reference frame was chosen as local reference frame, whose origin is consistent with the center of mass. The assumed mode method was used for discretizing the deformation parameter. The rigidflexible coupling dynamic equations of structure undergoing large overall plane motion were obtained based on the virtual work principle. Through several simulation examples, the difference between uncoupling equations and coupling equations was discussed, and the results show that the uncoupling model is not accurate enough and simple zeroorder model is more accurate and effective. The analysis provides an important basis for the subsequent motion controller design and vibration attenuation.

Abstract:The vibration characteristics on a highorder modal of a thin cylindrical shell is studied in this paper by analytical method under different boundary conditions. Firstly, the shell dynamics model is established by Galerkin′s method based on Love′s shell theory under simply supportedsimply supported, clampedclamped and clampedfree boundary conditions. Secondly, the modal characteristics are solved, and the highorder natural frequencies as well as threedimensional mode shapes are obtained. Finally, the results are compared with the data from the related literature and finite element method. The results show that the error values of natural frequencies using analytical method are less than 2% for the shell under simply supported boundary condition at both ends. The natural frequency increases after the first decrease when circumferential wave numbers are small, while it increases gradually when circumferential wave numbers are higher, but the natural frequencies increase significantly when axial halfwave numbers rise. Moreover, the threedimensional modal shapes obtained from the analytical method, related literature and finite element method are coincident.

Abstract:The increasing demand for advanced and largeaperture space antennas has promoted the remarkable development of the aerospace industry. The circular Antennas could be as small as possible during transportation, while it should be as large as needed for effective operation when the antenna is fully deployed on the orbit. Based on the earlier results, a equivalent circular cylindrical shell model is proposed to represent the circular continuum antenna, and the nonlinear governing equations of motion are derived for the equivalent circular cylindrical shell system under thermal excitation. By means of numerical simulations in MATLAB programme, the influence of thermal excitation on the dynamical behaviors for the nonlinear system is investigated.

Abstract:In order to improve efficiency, the gas and steam turbine cycle technology, represented by newly distributed rod fastening rotor system, gets fast development in electrical production departments. In this paper, nonlinear characteristics of the distributed rod fastening system are studied by a novel torsional vibration model. By using equivalent and simplification method, torsional vibration model of the distributed rod fastening rotor system are established. Based on the average method, analytical solutions and the amplitude frequency curves of the dynamic system are obtained. Further, the stability of periodic solutions of the dynamic system is studied, and impacts of the external excitation, damping and cubic stiffness are investigated respectively. Analysis results of the dynamic system have a guiding significance to design.

Abstract:Based on the higher order shear deformation theory, the globallocal 1, 23 mode is derived in this paper. Given the conditions of the continuity of inplane deformation and shear stress, as well as the free conditions of the upper and lower surfaces, the number of the independent variables for each node of laminated plate is reduced to 13, which is independent of the number of laminate layers. The displacement mode is then developed through rigidflexible coupling dynamics for laminated plate mutibody system. Based on the principle of virtual work, the dynamic equations for mutibody system are established through the hybrid coordinate formulation, where the continuity of the interlaminar stress is taken into consideration for laminated plate. The globallocal 1,23 displacement mode is obtained and verified against the exact solution in statics example. Finally, the comparison of the results obtained by the proposed method and the traditional method for laminated plate mutibody system illustrates the necessity of considering the continuity of interlaminar shear stress in simulation of laminated plate mutibody system.

Abstract:With the improvement of marine vibration index, the current static shafting alignment method is not yet suitable. The effect of shafting misalignment on rotating system vibration is not clear. Based on the mechanics analysis on elastic coupling of three different types of misalignment, the dynamic models of misalignment excitation are first established, and this dynamic model is also verified by bench test. The results show that under the excitation of shaft misalignment, the relative errors between the simulation results for the situations of synchronous harmonic, second harmonic and peakpeak vibration and the bench test data are less than 20%. Moreover, it is found that the increasing misalignment of elastic coupling results in strong vibration, accompanying with increasing excitation amplitude.

Abstract:Many practical problems should be described by nonlinear Markov jump systems involving both continuous and discrete variables. In this paper, the stationary response of stochastically excited singledegreeoffreedom (strongly) nonlinear system with Markovian jump parameters is studied. Firstly, the averaged It? differential equation with Markovian jump is derived based on the stochastic averaging method. Then, according to the Markovian jump principle, the finite set of (FokkerPlanckKolmogorov) FPK equations are formulated. The FPK equations coupled with each other through the absorptive terms and reductive terms. The stationary response and its statistics of the Markovian jump system can be obtained by solving the FPK equations numerically. Finally, as an example, the responses of a Markovian jump Duffing oscillator subjected to Gaussian white noise are studied. Numerical results show that the stationary response of the jump system can be regard as a weighted sum of the responses of nojump system, and the weighted value is determined by the jump rules.

Abstract:A new communication technique of transmitting Mary digital signals using projective synchronization based on stability criterion is proposed in this paper. At the sender, Mary digital signals are modulated into Jacobian matrix and the scaling factor of chaotic system. The digital signals are decoded in the corresponding subsystem constructed at the receiver end. Lorenz attractor is taken as an example to simulate the process of transmitting decimal digital signals by chaotic modulation. Numerical analysis shows that the communication system has higher transmission rate and decoding accuracy for the digital symbols without increasing complexity. The security and effectiveness of the proposed technical scheme is validated through the numerical investigation.

Abstract:Fault signal of rolling bearing is often weak periodic, and the chaotic oscillator is very sensitive to weak periodic signal with specific frequencycan detect the fault signal effectively. he mathematical model and the basic detection principle of the chaotic oscillator were introduced, the determination method of the dynamic critical threshold. The chaotic oscillator detection method was applied to the fault signal of rolling bearing, including the outer ring, the inner ring and the rolling elementwhether there was a fault signal through the changes between the output phase diagrams the detection of the fault signal rolling bearing was implemented effectively.

Abstract:Based on the modal superposition theory, the second order derivative of the modal coordination is firstly obtained from the acceleration of the bridge at several sections. The inertia force of the bridge is then expressed as distributed load by means of the d′Alembertian theory. Using the bending moment influence line of the bridge, the relationships between the moving load and the moment is proposed. The moving force can be obtained at any time points through the developed formula. Case studies show that this proposed method performs high accuracy in identifying timevarying as well as constant moving force. Moreover, this method doesn′t need to deal with the illcondition due to matrix singularity, which makes it in high efficiency and appropriate for engineering application.

Abstract:主要考虑弯曲变形的细长轴向运动梁,可以作为工程中广泛应用在航天器天线、液体输送管道、汽车驱动带、电梯缆索等的简化机构.对轴向运动柔性梁线性微分方程,采用复模态分析方法导出两端简支和固支边界条件下的固有频率方程;采用Ritz法建立轴向运动梁的有限单元法模型.基于该模型在多种边界条件下进行梁的横向振动分析,并开展定点激励下激励功率谱的辨识.仿真结果表明,与传统的Galerkin截断方法相比.有限元方法能够克服分析方法的建模困难,对复杂边界梁进行有效的分析,对激励的功率谱能够有效地辨识.