Advanced Materials Research Vols. 490-495

Abstract: In recent years, high-resolution Direction of Arrival (DOA) estimation with a sensor array has become indispensable for various applications. In actual measurement, however, DOA estimation accuracy is deteriorated by many error factors. For a uniform linear array (ULA), there exist algorithms for self-calibration for single-dimensional (1-D) DOA estimation. In this paper, we develop a simple self-calibration method for two-dimensional (2-D) DOA estimation with an L-shaped array.

Abstract: The process time of aircraft assembly line is easily influenced by the efficiency of workers, the supply circumstance of components and the assembly quality. While the aircraft assembly line is hardly to reconfigure after it is in use, in order to optimize the assembly line before its application, a new object-oriented modeling method based on hierarchy and stochastic petri net has been put forward in this paper. The behavior and the structural characteristics of the model have been analyzed according to the solution of linear invariant. Finally, the model of aircraft wing assembly line has been established as an example, which proves the feasibility of the modeling method.

Abstract: In this paper, a new electric-pneumatic convert device with piezoelectric composite disc as actuator is proposed. The new convert device break through traditional principle of force balance, which the parameters optimization to the whole air course and the structure of piezoelectric actuators were carried on by orthogonal experiment method. Experimental results show that the new device character is effected seriously by original installation site and has the characters of fast response, sensitive reaction, stable performance and meet the requirement of air pressure output between 0.02MPa and 0.1 MPa in industrial field with low voltage, which provides good basis of development of electric-pneumatic convert valve with new piezoelectric structure.

Abstract: Because of the based on S3C6410 Field information recorder mine- underground non-uniform illumination and mine- underground non-uniform illumination that a large of noise collected and transferred,image is low contrast ,dim and dark. Based on the theory of Donoho's wavelet threshold denoising, several typical wavelet threshold denoising methods are compared.the best denoising effect of peak signal to noise ratio is obtained. The image enhancement method that combination of the adaptive thresholding denoising and histogram equalization is proposed. The experiment result shows that the method has a good denoising performance, which removed the readout noise of CCD Camera,at the same time, image quality is improved .So the wavelet enhancement in image processing of mine- underground can improve image quality.

Abstract: An all terrain vehicle is a kind of special vehicle that travels on all-road. It should have better handling characteristics. In order to evaluate handling performance of an ATV, steady-state circular motion performance experiments about the ATV are done and steady state response characteristic is analyzed. The results show that the ATV studied has under-steering characteristics which is a good turning state and the results correspond with test report about Santana Xi5 on the road test at Journal of Motor Fan in Japan.

Abstract: Basing on the present situation of the controlling differential stage-less speed variator cannot accurate speed control, in a typical PX type differential step-less speed transmission as an example,analyses the moving relationship of various components in the entire device.Then infer the function relation between output speed and the angle of speed regulating handle.Establish the theoretical basis and foundation of the automatic speed control in the controlling differential stage-less speed variator.

Abstract: Based on the basic vector control theory of motor, the paper deduces the decoupling control theory of PMLSM, and researches on the current loop of PMLSM servo system. Through introducing voltage compensation loop into the current loop, the paper analyzes the influences of the relevant parameters on the response speed of the system in details, and proves the theory that introducing voltage compensation into current loop is actually good for improving the response speed of the system from the perspective of theory and simulation, meanwhile, the paper also analyzes the influences of voltage compensation loop on the stability of the system.

Abstract: According to the field geological sample classification, a spectral similarity the cluster analysis algorithm (SSCA) has been put forward. This algorithm expands and improves the spectra sort encoding algorithm on the spectral sorting and similarity computation, and adds similarity clustering analysis method. Testing on 100 field geological samples using SSCA algorithm, we get the results showing that this algorithm can make further classification for field geological samples to some extent.

Abstract: Magneto-rheological fluid damper(MRFD) is one of new type damper. Based on MRFD, a new model reference adaptive control(MRAC) system is designed in this paper, and it employed sky-hook damping control as model reference. Lyapunov stability theory is used to deduce adaptive control law, and simulation result indicates that MRAC system is not only can follow sky-hook control quickly and well, and it also can adapt to the road conditons, varaition of vehicle body mass and suspension system parameter

Abstract: In order to improve the overall performance of the engine cooling system, make the engine work in a stable and suitable thermal condition, a fuzzy controller for the engine cooling system was designed, then the cooling control model was established in Simulink, and the engine cooling system model of a diesel engine was built in GT-cool. Simulation computation was taken on the coupling of the two models. The results indicate that fuzzy control has visible effect for the improvement of the cooling system.