摘要：In this paper,we consider a multi-UAV surveillance scenario where a team of unmanned aerial vehicles(UAVs)synchronously covers an area for monitoring the ground *** this scenario,we adopt the leader-follower control mode and propose a modified Lyapunov guidance vector field(LGVF)approach for improving the precision of surveillance trajectory ***,in order to adopt to poor communication conditions,we propose a prediction-based synchronization method for keeping the formation ***,in order to adapt the multi-UAV system to dynamic and uncertain environment,this paper proposes a hierarchical dynamic task scheduling *** this architecture,we firstly classify all the algorithms that perform tasks according to their functions,and then modularize the algorithms based on plugin ***,integrating the behavior model and plugin technique,this paper designs a three-layer control flow,which can efficiently achieve dynamic task *** order to verify the effectiveness of our architecture,we consider a multi-UAV traffic monitoring scenario and design several cases to demonstrate the online adjustment from three levels,respectively.

摘要：Vehicle crashworthiness simulation is the main component of the virtual auto-body design. One developing commercial vehicle was simulated on crashworthiness by the non-linear finite element method. The bumper crashworthiness at the speed of 8 km/h was analyzed and valuated. On the other hand, the deformation of the auto-body, the movement of the steering wheel and the dynamic responses of the occupant at the initial velocity of 50 km/h were studied. The results appear that the design of the vehicle could be improved on structure and material. Finally, the frontal longitudinal beam, the main energy-absorbing part of the auto-body, was optimized on structure. Simulation results also show that applying new material, such as high strength steel, and new manufacture techniques, such as tailor-welded blanks could improve the crashworthiness of the vehicle greatly.

摘要：3D objects can be stored in computer of different describing ways, such as point set, polyline, polygonal surface and Euclidean distance map. Moment invariants of different orders may have the different magnitude. A method for normalizing moments of 3D objects is proposed, which can set the values of moments of different orders roughly in the same range and be applied to different 3D data formats universally. Then accurate computation of moments for several objects is presented and experiments show that this kind of normalization is very useful for moment invariants in 3D objects analysis and recognition.