Advanced Materials Research Vols. 433-440

Abstract: The purpose of this paper is to detect the echo under reverberation background by using adaptive interference cancellation. And in this paper, experimental data was treated. Reference signal is separately one single beam or symmetrical double beams in the processing of adaptive reverberation cancel. As the results shown, it is clear that the reverberation is made a great degree of inhibition after adaptive reverberation cancellation treatment. And when symmetrical double beams are as the reference signals, the effect is obviously better than one single beam.

Abstract: In tracking control system, control precision is influenced by the generation of control signals and precision of control is affected by data acquisition. Signals are easily interfered by environment after data acquisition．Therefore transmission standards and communication protocols are crucial links．Related links of this system was analyzed and discussed in this paper．

Abstract: Yalong Bay ice storage district cooling system is a very high degree of automation system, the stategies of which are detailed analyzed in the artical from three parts: refrigerating system, chilled water distribution system and user cooling exchange system. For the benefit of the environment and the oprerating efficiency of power grid, these control strategies are designed on cooling demand and peak load shifting. Now they have been successfully applied to Yalong Bay DCS, through the three control hierarchies: local control, centralized management and optimizing control. The artical has reference value for design on ice storage district cooling system control.

Abstract: This paper addresses the dynamic output feedback stabilization problem for linear time-invariant systems where the process disturbance preview is available to the controller via communication networks. A lower bound of data rates of communication channels, above which there exists a feedback control policy to stabilize the unstable plant with unbounded disturbance, is presented. Furthermore, the problem of bandwidth allocation in the communication channel is analyzed based on the system dynamics. Simulation results show the validity of the proposed scheme.

Abstract: A novel sample rate adaptation technique is proposed for the wireless sensor/actuator networks with packet reordering. Considering network-induced delay and packet loss, a new technique for adapting the sampling interval to network parameters is studied in terms of the Reorder Density, such that a closed-loop switched delay system is presented by constructing state feedback controller. Furthermore, a criterion for stochastic stability of WSANs is derived based on the stochastic theory due to the subsystems subject to Markov chain. An adaptive controller is designed by solving linear matrix inequalities (LMI). An example is given to show the effectiveness of the proposed method.

Abstract: A passive guidance method is used in midcourse guidance stage of long range air-to-air anti-radiation missile, which based on the passive location theory of moving single observer to moving radiant point. The special request of guidance law caused by passive guidance is studied, and a model of guidance law named “proportional guidance of swing object direction” is put forward. The model resolves the problem of midcourse guidance method for long range air-to-air anti-radiation missile, and the distance of “fire and forget” could be expanded to launch distance. The simulative trials and analysis of the result show that the guidance law could satisfy the observable condition of passive guidance, and the capability of trajectory is close to the one which produced by proportional guidance low.

Abstract: The magnetic circuit of MR damper was given,Finite Element Analysis and the structure optimization of MR damper were reserched.The theory of a variable domain by adopting an adaptive algorithm based on fuzzy-control was applied in semi-active suspension control with MR damper.The adaptive law for membership functiongs was designed for input and output.Based on 2DOF 1/4 car model with the simulationed for road protile as random input,the control simulation of MR semi-actibe suspension was carried out,results show that spring mass acceleration reduced while an adaptive algorithim with a variable domain fuzzy control was used to compare with ordinary strategy,the riding comfort got improved.

Abstract: The pumping unit is the main pumping equipment in the oil field. However, there widely exist such defects as low pumping efficiency, high energy consumption, much time and great efforts consumption in stroke adjustment etc. in the current pumping unit, resulting in serious waste of energy. Some energy-saving technologies in pumping units have been developed, but the effects are not quite good. Aiming at this situation, this paper introduces a new type of motor control theory - Direct Torque Control. By controlling the stator voltage, the technology achieves the direct control of the motor torque. Meanwhile, with the combination of the motor running condition of pumping units, study of energy-saving control based on DTC technology is carried out. It turns out that the energy-saving effect is significant according to the application and test results of the energy-saving control device in the oil field. Therefore, the control device can bring certain economic benefits and have the value of popularization and application.

Abstract: The characteristics of long distance gravity-fed pressure water-conveying projects are long pipe length, huge changes in rise and down of pipeline arrangement, and complex hydraulic conditions. It is the water hammer that mainly influences the safe operation of such projects. Based on a real long distance gravity-fed pressure water conveying pipeline system, fluid transients processes under different operation modes were analyzed by using the method of characteristics. The pipeline longitudinal arrangement is high in two ends and low in the middle part. The research puts forward that for such pipeline arrangement using valve set in the midway of the pipeline to control the system is evidently better than that of valve at the downstream end of pipeline. In this way, pipeline working pressure can be effectively reduced, in turn, the pipe pressure grade can be decreased and the investment of the project can be reduced.

Abstract: The temperature rise of generator components has a great impact on operation performance for large turbine generator. In this paper, applying the general FE calculation software-ANSYS, with a sequential electromagnetic-thermal field coupling calculation method, temperature calculation on phase lead connecting structures of 1100MW nuclear power turbine generator parallel rings is presented. The calculation results could offer a basic analysis to optimize the design of the generator.