Applied Mechanics and Materials Vol. 389

Abstract: Based on study of space vector modulation, cca novel over-modulation strategy of matrix converter is proposed for the problem of low voltage transfer ratio of matrix converter. According to the relation of the voltage space vector trace and hexagon trace vector, the control level is divided into linear modulation level and over-modulation level. The over modulation strategy is achieved by transforming the voltage modulation coefficient. The simulation results demonstrate that the voltage transfer ratio can be up to 0.955.

Abstract: Key tooth recognition is an important procedure of lock core assembly, it directly affects the assembly efficiency and qualified product rate. The current method is artificial and mechanical recognition, which has defects of mechanical loss, low precision and automatic degree. This paper proposes an innovative solution based on machine vision technology. The recognition system uses TMS320DM642 as the core processor. The image sensor MT9M001 acquires key image. The operation of image processing algorithm produces the key tooth code. Communication with the lock core assembly system uses 485-bus. The experimental result indicates that the method proposed in this paper is superior to the existing methods.

Abstract: Multiband transceivers are very popular nowadays. As a key component in the system, the broadband VCO is a hot research topic. This paper presents a broadband inductor capacitor voltage controlled oscillator (LC-VCO) with an adaptive frequency calibration (AFC) circuit. The VCO uses a 5-bit differential switched-capacitor array for extending the tuning range. Two couples of AMOS varactors are employed to linearize the VCO tuning gain. An AFC circuit is utilized to automatically select the optimal sub-band for the VCO by binary search algorithm.

Abstract: This paper proposes a multiple target air parameters monitoring scheme with the help of the wireless intelligence sensor array which is built up with multiple sensors. In the paper, the design of the wireless intelligence array sensor is considered, the method to configure the wireless intelligence sensor network is introduced, and the information combination arithmetic of sensor network is provided. Then, a kind of minitype wireless multiple target air parameters monitoring system is built up. Experiment result clearly indicates that the system can accomplish the mission of monitoring multiple targets at the same time and the efficiency and reliability, make the air parameter monitoring arrives at a higher level. So the system proposed should be widely used in the domain of air parameter and toxic and harmful gas leakage monitoring.

Abstract: This paper introduces the theoretical basis and the framework of improved algorithm of TLD(Tracking-Learning-Detection, TLD) algorithm. Difference between the improved TLD algorithm and traditional algorithm tracking were compared by experiments in the paper. When the improved algorithm has joined the online learning mechanism, it improves the effects of target tracking. Trough the experiments between the improved TLD algorithm and traditional algorithm, it turns out that TLD algorithm has good stability and robustness in target tracking.

Abstract: The data redundancy will produce in the procedure of gather of graphics and video or the data in the WSN, and then the data fusion is needed. On the basis of the previous method of data fusion, the data method based on information support (that is CRFSD) is provided, and through the simulation experiment, which is held in the time domain, spatial domain, temporal and spatial domain, the data fusion is realized.

Abstract: Optimal formation reconfiguration control of multiple is a complicated global optimum problem. In this paper, according to the characteristics of Uninhabited Combat Air Vehicles. A Novel Firefly Algorithm was used to solve Uninhabited Combat Air Vehicles, the redesign of the individual location update in the algorithm, and introduced a Levy flight to increase the population search domain. In addition, a local search algorithm is introduced to enhance the local search ability in this paper. the algorithm was experimented and the experimental results show that the new algorithm to be successful in locating multiple solutions and better accuracy. Series experimental results demonstrate the feasibility and effectiveness of the proposed method in solving the optimal formation reconfiguration control problem for multiple UCAV.

Abstract: In this paper, an effective method was proposed to formulate and solve a fuel-optimal satellites maneuver control problem using a continuous low-thrust system. The design of the bounded desired final satellite formation is a passive and periodic circular-like formation at critical inclination underperturbation, which adjusts to long-term flying formation. The nonlinear optimal control problem is converted into a nonlinear programming problem by the application of the Legendre pseudospectral method. Due to the design includes the free final time and the precise final condition constraint, fuel-optimal maneuver is more reasonable, thereby it will achieve the minimum fuel consumption.

Abstract: This paper describes the design and implementation of UART downloading with Ymodem protocol for multi-process micro-kernel embedded operating system on ARM, including overview of commonly used communication protocols via serial port (Xmodem, Ymodem, and Zmodem), key techniques of Ymodem protocol, design of the system call for Ymodem downloading, and programming essentials of shell command rx with Ymodem protocol. A demo example is provided at the final of the paper to show the usage and effect of the shell command. Practice proves that the performance and efficiency of Ymodem protocol is superior to that of Xmodem, while the program structure of it is simpler than that of Zmodem. Therefore, Ymodem protocol is particularly suitable for implementing downloading function with UART for embedded operating system.

Abstract: In order to overcome the shortcomings of precocity and stagnation in ant colony optimization algorithm, an improved algorithm is presented. Considering the impact that the distance between cities on volatility coefficient, this study presents an model of adjusting volatility coefficient called Volatility Model based on ant colony optimization (ACO) and Max-Min ant system. There are simulation experiments about TSP cases in TSPLIB, the results show that the improved algorithm effectively overcomes the shortcoming of easily getting an local optimal solution, and the average solutions are superior to ACO and Max-Min ant system.