Advanced Materials Research Vols. 765-767

Abstract: Servo loop bandwidth is an important parameter of the ship-borne servo control system to track targets fast, accurately, stably. This paper analyzes the structure and principle of servo system and the PID controller algorithm. Based on the fuzzy control theory, applies the parameter self-tuning fuzzy PID control technology to the servo system position loop successfully, and gets a satisfactory control performance.

Abstract: Multi-agent formation control is the process in which the teams formed by multiple agents move to specific target or specific direction. The formation method of the linear formation and circular formation are given in this paper, based on the geometric characteristics of the formation formed by multi-agent. The process in which 5 agents arrived at the designated target point and formed a linear formation is achieved through simulation; and 4 agents formed a circular formation and cooperated to carry heavy weights. The result of the three-dimensional simulation shows the feasibility of the method to form multi-agent formations in different environments and different tasks.

Abstract: To decrease the uncertainty of simultaneous localization and mapping of UAV, and at the same time, to increase the speed of searching the unknown environment at which UAV locates, an active SLAM trajectory programming algorithm is proposed based on optimal control. Therefore, UAV SLAM is tackled as a combined optimization problem, considering the precision of UAV location and mapping integrity. Based on the simplified UAV plane motion model, this algorithm is simulated and tested by comparing with the random SLAM algorithm. Simulation results show that this algorithm is effective.

Abstract: industrial Control System (ICS) performs the tasks of supervisory control and data acquisition of critical infrastructures. With the widely application of computer and network techniques, ICS suffers serious security threats, and malicious codes are one of the most serious security problems. However, there is absent of analysis methods specific for ICS malicious code behaviors in current times. In this paper, a framework for ICS malicious code analysis is presented. Firstly, the ICS attack graph model is established based upon the hierarchical structure of industrial control system and the suffered security threats, which formalizes the attack process of ICS malicious code. Secondly, the runtime information of ICS malicious code is detected and collected for analyzing and assessing the attack behaviors and the resulted impacts. Finally, the ICS simulation environment for malicious code analysis is constructed based upon the framework and the experimental analysis of ICS malicious code is performed which preliminary validates the effectiveness of the proposed framework.

Abstract: By analyzing the current serial communication design used in a popular monitor system composed of PC, GOT and PLC, introduced a new design and implementation plan of serial communication based on Vb and MX software pagekage. This system could solve the problem of managing complex communication protocol in current application, and achieved the efficient, stable and reliable communication under simple attachment. The system could not only have not to consider complex communication protocol but also need not to set up the D8120 PLC, and MX Component with other application such as GX Developer could use com port at the same time, so debug conveniently and programming high efficiency. In the actual application, No matter the accuracy and stability of communication were to achieve achieve industrial control system requirements.

Abstract: By using laser-diode as pumping source, a passively Q-switched Nd:YVO₄ laser with Cr⁴⁺:YAG saturable absorber is realized. Considering the Gaussian distribution of the pump beam and the oscillating laser intensity, the coupled rate equations of a LD-pumped passively Q-switched laser with Cr⁴⁺:YAG saturable absorber are given. The relations between the pulse width and the pump beam radius in the gain medium as well as the laser beam radius in the saturabe absorber are obtained from the numerical solutions of rate equations, and the theoretical calculations agree with the experimental results.

Abstract: The PID control is most widely used in industry and its parameters setting is an important issue in the field of automatic control. In this paper, a novel tuning strategy based on multi-objective genetic algorithm (MOGA) and multi-attribute decision-making (MADM) method was proposed. The proposed strategy can balance the four performances simultaneously regarding accurate set-point tracking, disturbance attenuation, robust stability and energy consumption for actuator. The estimated Pareto-optimal set was obtained by MOGA and then an appropriate solution was selected from the set by ranking with a simple additive weighting method (SAW). To demonstrate the proposed strategy, an example of the ship course PID controller with filter for a 150,000-ton tanker with steering gear was studied. The results show that the PID controller is stable and robust with high dynamic quality.

Abstract: In order to solve the problem of the communication asymmetry problems in hybrid ad hoc network because of the introduction of directional antennas, we propose a hybrid MAC protocol termed DFMAC protocol, which achieving data transmission by one hop through the use of exchange RTS by multiple hops. The protocol takes the benefit of directional antennas and can be used by node equipped with Omni-directional antennas, simulation results show that the DFMAC protocol performs well in improving the network throughput.

Abstract: Along with the development of the aviation industry, HM sports get more and more attention, it was a very hot sport at home and abroad, the remote control technology of model aircraft is also have been developed. In the present model aircraft remote control systems, the antenna is usually dipole antenna, dipole antenna is larger, higher power consumption . In view of the above shortcomings, this paper proposes a way that using micro-strip antenna instead of the traditional antenna. Through the discussion of the microstrip antenna's working principle, this paper designed a microstrip antenna works in 2.4 GHz model aircraft remote control system. According to its actual application , the material, shape, and the type of the microstrip antenna are determined, and the size of the antenna is calculated by the equation and the software , then the model of the antenna is built and simulated in ADS, finally the best parameters are obtained through optimizing and matching to meets the requirements.

Abstract: The paper proposed a remote monitoring and control system based on JavaFX and Web Service .In the system, communication stations were disbursed over a wide area. In a cell site, different kinds of sensors communicate with station program based on ARM. Cell sites uploaded the information of alarms and videos to the server. Server provided remote methods to the remote client through the Web Service. Operation of the system shows that, the proposed system has good openness and expansibility.