Applied Mechanics and Materials Vols. 490-491

Abstract: Considering the requirements of convinced sensor measurements for engine control, a method of aircraft engine sensor on line fault diagnosis and recovery based on least squares support vector machine (LS-SVM) is proposed. First, sensor sets correlations are calculated and the sensor with high correlation is selected by correlation analysis. Then sensor LS-SVM prediction model is established with the sensor itself primary data series and used to sensor fault diagnosis. The sensor recovery module is obtained based on the LSSVM algorithm with the high correlated sensor set, and is activated as the sensor failure detected. Experimental results show that the engine sensor fault recognition rate is satisfied by the proposed method, and could be used to turbofan engine sensor fault diagnosis and data recovery.

Abstract: Distribution networks are directly connected to the users and the reliability of its power supply is able to reflect the structures and the operating conditions of the whole power system. In the analysis of distribution system reliability evaluation, it is unlikely to get the exact value of the model parameters and is necessary to consider the uncertainties. The network structure, the reliability parameters and load level and their effects on the reliability are studied in quantity and the results are proved in the case.

Abstract: This paper presents the static and bearing test research with adopting the full size model on the cable anchorage zone of the main girder of the Xiamen-Zhangzhou Bridge. According to test result. It verified correctness of its design and feasibility of its manufacturing techniques·

Abstract: The larger area threshold scan window in star image is scanned with conventional star tracking algorithm under large maneuvering of the vehicle. This results that the number of calculating angular separation between two stars is increased. So the update rate of star sensor is decreased and the feasibility of errors star locations is increased. So, an autonomous predicted star locations algorithm with high angle velocity is presented in this paper. Firstly, the actual star locations are obtained within the threshold scan window of corresponding ideal star locations calculated by last frame in the current star image. Secondly the current attitude information is calculated with the obtaining actual star locations. Thirdly, the next ideal attitude is calculated with current attitude and last attitude. Finally, the next ideal star locations are calculated with the next ideal attitude. At last the algorithm are tested not only simulation but also at night sky experiment with the angular speed maneuvering of aircraft is 5.208681°/s in 2013. And the algorithm has be applied star sensor of satellite GNC.

Abstract: VDI type-1 rig and JIS rig are the two major testing rigs for cleanable fabric filters. We measured the filter cleaning performance using these rigs and the results were compared in order to characterize the two testing methods. It is found that filter cleaning has no direct relation with flow type of test rig. And configuration differences between VDI type-1 and JIS rigs causes the various differential pressure development curves in which VDI type-1 rig shows a little higher cake release effect than JIS rig. Moreover, a new concept of impulse per unit area is introduced for the evaluation on filter cleaning performance in a quantitative way.

Abstract: In general, when using the three-dimensional measuring machine to test a workpiece, the measuring route should to be planned firstly. Regarding workpieces which are formed by elementary curve or surface, there are specific software installed in the Coordinate Measuring Machine which can be used to generate the measuring route. However, when there are workpieces with no mathematic model, measuring process usually has to be done by manual operation. In this paper, we concentrate on the technical problem of measuring the blade with complex surface. After analyzing the geometric characteristics of blade, we did research on the self-study function of the Coordinate Measuring Machine, and finally put forward a method to rewrite the self-study measuring program according to geometric characteristics, which will successfully realize the automatic measurement of complex curved surface.

Abstract: This paper presents a new calibration method for binocular vision system, based on CPSO-BP neural network. Firstly, the training set of the back propagation (BP) neural network is formed by the image feature point extracted from the binocular vision system. Then the cooperate particle swarm optimization (CPSO) algorithm is introduced to optimize the weights of the BP neural network, making the network with a stronger ability of the global optimization. Experimental results demonstrate that the proposed CPSO-BP-based algorithm has a higher calibration precision than the traditional BP-based calibration method.

Abstract: In order to overcome some disadvantages of LS-SVM, such as noise-sensitive and less sparsity, adaptive weighted p-norm LS-SVM is proposed. Experiments shows that different data, using a different regularization(p) can improve the accuracy of the regression, where 1<p<2. p-norm LS-SVM can be convented to the form of compressed sensing, then it can be solved using IRLS. For each sample, because they are not the same, weighted membership degree is introduced to the optimization function so that leading to less error. There are some parameters of weighted p-norm LS-SVM, genetic algorithm is introduced to obtain the optimal parameters. Case study shows that adaptive weighted p-norm LS-SVM is better than other SVM and good result is obtained.

Abstract: In this study, the marginal spectrum based on instantaneous parameter is applied to the active Lamb wave-based health monitoring of plate structure to investigate the marginal spectrum variation of the signals after being added with damage scattering signal. First,the active Lamb wave monitoring technology is employed to obtain the Lamb wave signals of the plate before and after damage. Then the marginal spectra of the signals before and after damage are obtained using the HHT technology and compared with the spectrum of the signals. The results show that the marginal spectrum can better describe the variation of the signals before and after damage.

Abstract: Safety analysis is widely appreciated for critical systems. Model-based safety analysis is emerged under the background of mode-based development. For automated model-based safety analysis, extended models should be translated into script of input of formal analyzer. Consequently, many translation systems are constructed. In this paper, we explore the translating method between Stateflow models and Alloy, which is a declarative specification language for expressing complex structural constraints and behavior in a software system. Concrete translation systems could be built based on the method.