Applied Mechanics and Materials Vols. 128-129

Abstract: This paper proposed a voltage dip analyzing method for multiple faults condition in complex power network. This method regarded the fault points as virtual buses and introduced multiple fault position parameters into voltage dip analysis. It expanded the node impedance matrix by calculating the self-impedance of the virtual bus, the mutual impedance between virtual bus and non-fault bus, one virtual bus and another. According to the faults boundary conditions, each fault current phasor was calculated. The fault voltage function of any bus related with the multiple fault position parameters in the power network was derived. The voltage dip analysis result was obtained associated with the voltage dip threshold. The proposed method was validated in the standard IEEE-30 bus system.

Abstract: Firstly, the conception of hypersonic flight and its flight characteristics are introduced in the article. Secondly, a control method based on the structured singular value theory is proposed, and the necessity of this method whether can be applied to design the hypersonic vehicle controller is discussed. And then taking a model for example, the robust controller of hypersonic vehicle is designed. At last, the control effect of this controller is proved better through the simulation result. It also turned out that the controller has excellent command track performance.

Abstract: This paper mainly introduces a binocular eyes system which is similar to the human eyes. The whole control system is based on neural network control model of human eyes, while the structure adopts spherical parallel mechanism to mimic the human eye movement. The whole Binocular control system consists of DSP embedded control system and PC platforms, which achieves the movement of the vestibular ocular reflex, convergence and conjugate movement, thus realizing good tracking of moving targets. This control system has compacted configuration and high reliability. A large number of experiments were done to validate the whole excellent system performance.

Abstract: Considering the nonlinearity and strong coupling of AC induction motor, a co-evolutionary control method is proposed for it，based on this method, distribution function is introduced to regulate the probabilities of individuals production to promote the speed of evolutionary according to the characteristic of control system . Compared with the traditional genetic algorithm, the searching space has been decreased greatly by the method. Furthermore, tested on AC induction motor, the controller in this paper has the traits of high-speed response and small overshoot so on.

Abstract: Drilling along a specified route is required in more and more applications. This paper introduces a path controllable drilling device based on fluid power, which requires no electric power and thus especially suitable for mine rescue. The mechanism design, control method and working mode of the most important part of the device, a 3-DOF hydraulic steering system, are illustrated. An analytical model is also provided to estimate the invisible posture and orientation of the steering system and thus the drilling path of the device as working underground.

Abstract: Hybrid intelligent control technique is used for ship power station synchronous generator excitation control in this paper. The parameters and structure of the excitation controller are learned and adjusted through a hybrid learning algorithm combining self-organizing learning with BP learning. This algorithm converges much faster than original BP learning. Simulation results show that the synchronous generator excitation controller based on the learning algorithm can significantly stabilize terminal voltage.

Abstract: The Dual Buck Half Bridge inverter has been widely researched because of no bridge arm shoot-through problem and higher efficiency. Because the switch frequency always varies, the output filter parameters are very difficult to optimally design by using hysteresis current control. In this paper, a SPWM control method is proposed. The control method not only can be easy realized, but also get the no-biased current model. Finally, the proposed SPWM control method is verified by the simulation and experiment results.

Abstract: Online estimation of instantaneous frequencies is a method to treat information signals by following a set of certain algorithm for the purpose of extracting the sine wave signal frequency that is overwhelmed in the noise. Among several algorithms available nowadays, two are selected here-one is the modification of Rife (MRife) algorithm based on frequency-domain analysis; and the other is the correlation series based (CSB) algorithm. With simulation methods, the estimation error, stabilization time and computation load of these two algorithms are analyzed and compared respectively. Finally, these two algorithms are applied to estimate the vibration signal frequency of the diesel engine’s base under normal operating conditions. From the results, we come to the conclusion that MRife algorithm and CSB algorithm both have their specific advantages, whereas MRife algorithm is more applicable in the view of estimation error.

Abstract: To fulfill the practical demands of airborne equipment’s miniaturization and integration, topic around single antenna radar altimeter become one hot topic. But the problem of leakage signal greatly limits its applied scope. To solve this problem, first，carry out qualitative analysis on the leakage single of the single antenna altimeter; secondly, apply the Reflected Power Canceller (RPC) to the receiver of the single antenna altimeter system, and then propose the optimal design; afterwards, implement the theoretical analysis of leakage signal and the echo signal of the altimeter; finally, simulation of the cancellation performance is carried out, and the results indicate that the effect on cancelling is significant.

Abstract: Moving objects tracking in video sequences are the fundamental and challenging research topics in computer vision area at present. They have great research and application values in modern industry, military, avigation and spaceflight area. But so far robust object tracking is still an open problem especially when the scene is complex. The main obstacles in the research are the scale of object, occlusion, background complexity and other non-rigid deformation. The system presents an integration of Kalman prediction [1] and Mean-shift [2] tracking method. A large number of experimental results show that the proposed tracking algorithm not only can improve the reliability and accuracy which traditional tracking algorithm cannot, but also can improve the real-time performance which SIFT tracking algorithm fails.