Applied Mechanics and Materials Vols. 427-429

Abstract: The state feedback control using sum of squares technique (SOStools) combined with the nonlinear observer is applied to the depth control of a submarine. The mathematical model of the submarine is rewritten as the linear-like form, then the uncertainty caused by the variation of the hydrodynamic coefficients is treated as the disturbance, which can be estimated online by a nonlinear observer. The method can provide good robustness against the nonlinearity as well as the uncertainty, which is verified by the simulation.

Abstract: A novel intelligent algorithm of orthogonal optimization is introduced for electronic circuit parameters. The orthogonal optimization design develops from conventional orthogonal design. According to the results of variance and variance ratio analysis in the orthogonal design, the next searching direction and range of each variable are determined, which is able to be circulating in the optimization of searching. The orthogonal optimization solution is performed intelligently until error value of the variance ratio for each variable is approximately equal. Since the tolerance of an optimal solution is obtained when the parameter design is completed, this method does not need special tolerance design. The authors take a stabilized power supply circuit as an example to optimize the circuit parameters. This method has less calculation amount, shorter searching time, more rapid speed and higher accuracy of optimization searching. Optimization results show that this algorithm is much better than other current algorithms of intelligent optimization methods.

Abstract: Registration and nonlinearity are two crucial factors affecting the performance of the two-station passive locating system. In this paper, an online joint registration and data fusion algorithm is proposed to estimate the sensor bias and target state simultaneously using the angle-only measurements from the two ownship stations. The system model of the passive radar is firstly developed followed by the expectation-maximization (EM) approach dealing with the derivation of maximum likelihood (ML) function of the complete data. The unscented Kalman filter (UKF) is chosen to alleviate the influence caused by nonlinearity generated in the measurement function. Computer simulation shows that the proposed method is effective and reliable for this specific tracking scenario.

Abstract: Single Reflector Panoramic Imaging System (SRPIS) has been widely used because of its advantages such as simple structure, fast imaging, integration and miniaturization. It can observe objects around the reflector mirror, which fits for the quality inspection of gun barrel bore. However, its images often suffer from serious distortions in radial and tangential directions. Therefore, to ensure the accuracy of captured images, distortion must be eliminated. In this paper, a distortion correction method is proposed based on the imaging characteristics of SRPIS. Firstly the relationship between the height of a certain point on the gun barrel bore and the radius of image point is derived. Then the correction model is built based on the relationship. Aiming at the captured annular image, a new chessboard corner detection algorithm is proposed. The correction parameters are obtained by using the algorithm according to the labeled image. The real experiment results demonstrate that the correction effects of radial and tangential distortions are satisfactory. The error is controlled at sub-pixel level.

Abstract: In this paper, a measure system based on acoustic resonance is developed for hazards materials classification. It employs the lock-in amplifier as core processor to collect the acoustic resonance spectroscopy (ARS) of sealed containers which storied hazards materials. The transmitter and receiver are coupled externally to the wall of the container. The transmitter generates the sound by using a swept frequency source. The receiver on the opposite side of the wall of the container can detect the transmitted signal. The acoustic properties of hazards materials such as velocity and attenuation can be learned from the observed spectrum signal. Then multivariate methods are used to evaluate pretreatment methods, such as normalization, and classification possibilities of data collected by ARS in a laboratory environment. Principal component analysis (PCA) shows that it is possible to observe differences between samples using the data acquired from the ARS system. Further results obtained from Linear Discriminant Analysis (LDA) show that the identification rates for hazards materials classification are 100%.It is concluded that the ARS system has significant potential in the hazards materials classification.

Abstract: Radio telemetry is used as a major way on monitoring flight test of airplanes. As information transition channel is disturbed or interrupted significantly during the blackout area during flight, the carrier information will not be transmitted normally. However, the airplane data during the blackout period has to be monitored seriously. This issue can be resolved by building re-issued data memory function into a telemetry system. This paper looks at the research of re-issued data memory technology and proposes a new design of re-issued data memory circuit for realizing the negative trigger delay storage of data flow in telemetry system during blackout period. The delayed data in the storage will be transmitted again later. The new designed circuit uses multiple re-issued data memory methods to satisfy the requirements of different telemetry tests and measurements, assuring complete data during airplane flight test.

Abstract: The work of the automaton fault diagnosis based on experimental measurement has not been researched except the fund project which this paper was come from. First, study the structure characteristics, movement process and several common failure modes of the automaton. Then we combined the automaton movement process analysis and the nonlinear, short-term impact characteristics of the vibration signal, proposed for the first time with a powerful tool for nonlinear problem researchthe chaos theory, to research the fault diagnosis of automaton, and finally realized it. It provided a new way for the fault diagnosis of automatic weapons. That has important theoretical and practical significance for high speed automatic fault diagnosis.

Abstract: The high-speed synchronous node machine is developed for collecting high-precision and synchronous data from multi-chip CCD to measure the dynamic object with large field coverage by Visual technology. Node machine contains core, A/D converter module and Ethernet communication module. The FPGA of 600,000 gates which have a built-in FLASH chip is used as the core, which provides work-frequency of 10MHz and drive pulse for multi-chip CCD. A/D converter module configures the differential amplifier and builds 3-way 30MHz 16-bit A / D converter. 10/100M Ethernet protocol stack controller and RJ45 interface are internally installed in Ethernet module. This module also uses CC2430 chip to perform fast wireless synchronization control. Paper emphasizes how to implement the key technologies of multi-chip CCD for synchronous and precision measurement, and test the node machine by 5-chip CCD image data synchronous collecting with large field of vision. The node machine runs smoothly and reliably .The performance results of test show that the speed of image data collecting reaches up to 1800 frames/s, the speed of data processing reaches up to 150M Bytes/s and the transporting speed reaches up to 50M Bytes/s. The time of synchronous control is within 2 us.

Abstract: An efficient design method of four parallel channels in-order FFT with single floating-point butterfly is proposed, to reduce the resource consumption and improve the real-time calculation ability. The radix-4 FFT is deduced to calculate the access address for four channel data parallel. The hardware architecture of the proposed FFT is presented, and the single precision floating-point adder and multiplier are also depicted. The proposed architecture of a four channels 1024 points radix-4 FFT with single butterfly is implemented in FPGA, and the performance is compared with previous literatures and some EDA corporations IP cores, which shows the correctness and effectiveness of the proposed method.

Abstract: The mathematical model of the tracking and positioning system was presented and established by analyzing the kinematics of the free pendulum system. According to the system designs requirements, a performance dedicated circuit was designed for it. The sensors, controllers, and execution units were selected. The circuit of control system was designed. A system was made for debugging and a high-performance fuzzy controller was designed. Its algorithm was based on the fuzzy control PID theory. The core of the fuzzy controller was a set of fuzzy associative memory rules that correlate each group of fuzzy control input sets to a fuzzy control output set. We finished the high precision tracking and locating system design. Through the system performance test, test results showed that the system had good performance.