Applied Mechanics and Materials Vols. 513-517

Abstract: The directional well technology is developing with the increasing demand for energy, and the computer science plays an important role, which not only decrease the design time of the directional well, but also improve the drilling accuracy. The application of computer in rotary steering system makes it possible to realize the intelligent Directional well system.

Abstract: The rotor side converter of DFIG with stator flux-oriented vector control was presented with the mathematical model created and the control structure analyzed. The neural networks internal model control was proposed in this control system which composed of NNC and NNM, the NNC was the inverse model of neural networks, which serve as controller, NNM was the positive model of neural networks, the control feature was verified with simulation.

Abstract: In order to solve cylinder-scraping of a four-cylinder high speed diesel engine, based on the measurement of piston temperature, the piston temperature field was numerically simulated by using temperature fitting method, the calculation results were well consistent with the measured temperature. By finite element analysis of piston thermal load based on the calculation results as temperature load, enlarging oil cooling cavity in the piston head was proposed to enhance cooling locally, which could effectively reduce temperature of the piston head and the first ring groove and avoid the occurrence of cylinder-scraping.

Abstract: Airborne radar reconnaissance system will produce a map projection angle error in actual, which further causing the positioning error. To correct these errors, the paper proposed a map projection positioning error correction algorithm. The algorithm firstly calculate the reference point using the Mercator isometric projection, and then calculate map correction angle with the inverse projection, at last eliminating the error caused by reference distance estimation using the iterative cross positioning, which improving the location accuracy. Experiments show that this method is reasonable and effective.

Abstract: This paper proposed a soccer robots attitude detection method based on the principle and vibration mode of cymbal piezoelectric composite transducer. Cymbal piezoelectric composite transducers and MEMS-based three-axis low-g sensor were set on some different support points of soccer robot's joint to accomplish attitude detection. The signal processing circuit and algorithm software were designed. The research results showed that the performance parameters of the soccer robot falling down attitude detection system based on cymbal piezoelectric composite transducer are better than the other sensor, such as the sensitivity, correct, undetected fall and stability duration, etc. The experiment results showed that the detection accuracy for falling down of the soccer robot can be 98% and the stability duration can be 60 minutes.

Abstract: With the assistance of Wide Area Measurement System (WAMS), this paper proposes a method based on Prony algorithm to identify Low Frequency Oscillation (LFO) online and apply Power System Stabilizer (PSS) for rapid suppression. WAMS monitors the power system in real time with high precision. When LFO occurs in the system, applying Prony algorithm to analyze the power angle, it can identify all kinds of LFO modes online. For each mode, PSS would be rapidly configured and applied into the system. When some LFO modes are successfully suppressed, the corresponding PSSs exit. Taking the 10-generator-39-bus system of New England for example, it verifies the correctness and effectiveness of the proposed approach.

Abstract: In this paper, an analysis and study regarding the characteristics of THz receiver noise using diode parameter error are performed. For a sub-harmonic mixer designed based on this type of diode model. Finally, this type of mixer was adopted to build a 183 GHz receiver system . The special are study the influence of the diode model process error on the receiver system noise characteristics, based on theory and modeling. The results show that diode ideality factor ns change exerted the greatest influence on the noise factor of the front end of the receiver, as well as similar influence over bias junction capacitance Cj and bulk resistor Rs, and minimal influence over saturation current Is.

Abstract: Inertial navigation system using IMU (Inertial Measurement Unit) of the flying space positioning data POS (Position & Orientation System) synchronized scanning of the hyperspectral remote sensing OMIS (Operational Modular Imaging Spectrometer) image correction, obtaining from the IMU in sync with the attitude parameter OMIS , the coordinate transformation parameter calculation and flight attitude, according to OMIS imaging principle of mathematical calibration model, the corrected image pixel re-sampling, the image correction, and achieved better image processing results.

Abstract: A novel medical image retrieval method based on Simplified Multi-wavelet Transform and Shape Feature was proposed in the paper, which included coarse and fine retrieval procedure. In the procedure of the coarse retrieval, Canny operator was used to extract edges of images. Moreover, contour lines were obtained by using the method of scan lines. At last, the coarse retrieval results of the images can be accomplished by using contour lines of images. In the procedure of the fine retrieval, the simplified multi-wavelet transform was used to decompose images at first, then, only the high frequency coefficients in the vertical directions were selected as retrieval objects. And hierarchical retrieval strategy was selected to accomplish the fine retrieval. This method not only can reduce the computational complexity effectively, but also can make full use of high frequency information of original images. Experiments showed that the accuracy of the retrieved results can be ensured.

Abstract: In this paper, we propose a method for structure lane detection; the method is based on two features: color and direction. This method can improve the robustness and accuracy of lane detection. Two kinds of saliency map have been calculated: color saliency map and direction saliency map. The final saliency map is the combination of the two map mentioned above. The binary image is getting from the final saliency map, and the feature points which used for fitting have been selected. The road region is segmented by the lanes. Experiment result shows that the proposed method produces better performance against some other methods.