Applied Mechanics and Materials Vols. 198-199

Abstract: An implementation framework of stepped-frequency LFM (SF-LFM) radar echoes simulator is presented in the paper based on the decomposition and calculation of SF-LFM radar echoes of a moving target. The proposed method can be implemented conveniently with direct digital synthesis (DDS) logic resource. The feasibility of this resolution is verified with computer and semi-physical simulations experiments.

Abstract: We propose a simple control method to suppress two-lane traffic congestion for full velocity difference (for short, FVD) car-following model. The influence of lane changing behaviors is also studied in the stability of two-lane traffic flow under the boundary condition, and the friction interference which is from the neighbor lane has been taken into account. We derive the stability conditions by the control method. The feedback signals, which include vehicular information from both lanes, acting on the two-lane traffic system have been extended to the FVD car-following model. Theoretically, lane changing behaviors can break the stability of two-lane traffic flow and aggravate traffic perturbation, but it is proven that the congested traffic in two-lane traffic flow could be suppressed by using this control method.

Abstract: A simulation model of the linear engine system is built in this paper. The cylinder pressure data obtained through engine experiments is used to validate the accuracy of the simulation model. Based on the model, the combustion characteristics and external characteristics of the linear engine system were studied. And the maximization model is used to find an optimum operating region of the linear engine. The results show that, as the air fuel ratio(AFR) decreases under a steady engine speed, both the cylinder pressure and brake power increase first and then decrease, reaching their peak value when the AFR is 12. Under this AFR, the maximum brake power is 16.83kW at 6500rpm. Meanwhile, the fuel economy and the power performance reach the optimum combination within 5200rpm and 6500rpm.

Abstract: A modified car following model is put forward considering the headway distance of two successive vehicles in front. A control method to suppress traffic congestion is proposed for car following model. According to the control theory, the stability conditions are derived. The feedback signals, which act on our traffic system, consider two velocity difference effect. The control signals will play an effect only if the traffic state is in congestion. The corresponding numerical simulation results are agree well with our theoretical analysis.

Abstract: The projection pursuit regression theory is applied to analysis the reliability of vehicle hydraulic brake system and build the projection pursuit regression model. This model on training sample fitting effect is good and shows extremely strong adaptability. We predict the reliability of certain type hydraulic brake system by this model which provides scientific basis for research on reliability of hydraulic brake system.

Abstract: In this paper the qualitative behaviors of the two correlated units redundant system with two types of failure were discussed. By using the method of functional analysis, especially, the semigroup theory of bounded linear operators on Banach space, the well-posedness and the existence of positive solution of the system was obtained. By analyzing the spectra distribution of the system operator, the dynamic solution of the system asymptotically converges to the nonnegative steady-state solution which is the eigenfunction corresponding to eigenvalue 0 of the system operator was proved.

Abstract: This paper ascertains the battleplane’s tactics applied in Air-Confront-Ground simulation, constructs the battleplane Agent’s tactics system, and illuminates the main module of the system. Then taking the Attack-elevate tactic for example, the math model of the tactic is founded primarily, and the process of tactics’ choice and evaluation is analyzed, at last the executing algorithm of Attack-elevate tactic is generated.

Abstract: This paper introduces a framework of parallel control and management for space target system (STS). An artificial space target system is a new type of astronautics simulation software that employs agent modeling, large scale calculation and concept of artificial societies to support the research and development in space engineering. First, introduce the concept of parallel system. Then, pose the definition of artificial space target system and its framework based on multi-agent modeling technology, an artificial STS that is consistent with realistic operations of the actual STS is constructed different kinds of computational experiments are performed on the artificial STS, followed by analysis and synthesis with a case. Finally, future work and issues related to operational mechanisms and strategies for such implementation are also addressed.

Abstract: The purpose of virtual instrument measurement system architecture design based on database management is to expand stand-alone mode into the measurement mode of network. Through computer network, multiple virtual instrument measurement networks for data storage, communication and control the formation of network measurement applications are realized. This article discusses the formation of virtual instrument based on the database and computer network monitoring and control network programs, measures and achievement.

Abstract: A new method of stability margin clearance of missile autopilot is described. First, a model of linear fractional transformation form is established for missile has uncertain parameters; then, the system stability margin requirements are seen as a virtual uncertainty and introduced into the model; Finally, the model is analyzed, and the clearance results about the missile autopilot performance is obtained. The results show this is a more efficient and accurate clearance method than traditional ones.