Advanced Materials Research Vols. 468-471

Abstract: A method for chaotic synchronization system based on nonlinear control was studied. The general approach to chaotic system is following Logistic map. First, the parameter which meets chaotic status was analyzed and found via bifurcation diagram and Lyapunov exponent spectrum. The system can be synchronized quickly after just only a single iteration. Then, the method of implementing the synchronization system within a chaotic parameter modulation based communication system was researched. The deduction and simulation results also showed the probability for implementation the system in fast secure chaotic communications that require instant synchronization schemes. Finally, the chaotic system was applied in image transmission and the simulation results were also given.

Abstract: Rim is an important part of the wheels. It is often over loaded and has a complicated stress in use. Specially, at high speed circumstances, the quality of the work piece is closely connected. This paper combines the water immersion technology with the ultrasonic phased array technology to wheel detection. It introduces the basic principle, current situation at home and abroad of the water immersion ultrasonic phased array technology, and the comparison with the contacted ultrasonic phased array detection technology. According to the feature of the rim flaws, the methods to detect rim flaws with water immersion ultrasonic phased array technology are analyzed and tested. This system can finish the whole scanning in one time, improve the work efficiency and satisfy the testing requirements.

Abstract: Considering the good forecasting capability of BP neural network, a new crack damage identification method for reinforced concrete simply supported beam is proposed in this paper. After simulating the crack damage of a reinforced concrete simply supported beam, the natural frequency of the beam is chosen as the input parameters of the BP neural network. The data before and after damage of the simply supported beam are put into the trained neural network to judge the structural damage. The results demonstrate that the approach has a better application prospects in structural damage identification.

Abstract: This paper introduces the neural network PID control method, in which the parameters of PID controller is adjusted by the use of the self-study ability. And the PID controller can adapt itself actively. The dynamic BP algorithm of the three-layered network realizes the online real-time control, which displays the robustness of the PID control, and the capability of BP neural network to deal with nonlinear and uncertain system. A simulation is made by using of this method. The result of it shows that the neural network PID controller is better than the conventional one, and has higher accuracy and stronger adaptability, which can get the satisfied control result.

Abstract: The colonoscopic robot with continuum structure can offer enhanced environmental interaction by deforming to fit environmental constraints. In order to improve its perception ability and avoid perforation and other kickbacks, it is necessary to integrate pressure sensors into colonoscopic robot. A surface pressure sensor for the measure of contact pressure between colonoscopic robot and colon wall is designed. The sensor is made of aluminum and is 15.6mm in diameter and 3mm in width. It consists of external ring, internal ring, connection and two resistance strain gauge. The mechanical structure of the sensor is introduced. The mechanical characteristics is analyzed and simulated by the finite element analysis software ANSYS. The experiment system is built and the data is sampled through Wheatstone bridge. The data fitting is performed based on least squares method with Matlab software. The result shows that the surface pressure sensor has advantages of good linearity and accuracy. This study lays a foundation for the practical application of colonoscopic robot.

Abstract: The paper proposes a novel method of improving the traditional composite grating in 3-D measurement of the specular objects. The traditional composite grating is improved by altering the intensity of the center stripe in one of the fringes. The improved composite grating not only includes the primary phase information, which is modulated by the object's surface, but also includes the code information, which is necessary for the phase unwrapping. The paper introduces the formation of the improved composite grating, demodulating the composite grating and computing the unwrapped phase based on the altered fringe. Simulated and actual experiments prove that this method is valid. Because of projecting a single composite grating, the method is suitable for dynamical measurement.

Abstract: Relative to serial robot, parallel robot gets more and more attention of scholars because of its many advantages. However, there are some problems in the current research such as the chains’ coordination and coupling control, which has became one of the key problems in the motion control of parallel robot. To further enhance the motion control performances, a novel sliding mode control method base on synchronization error is proposed in this paper. The simulation and experiment results show that the designed control system has good tracking performance, small system error and strong robustness, which can satisfy the high-precision requirements of the parallel robot control.

Abstract: This paper studied the activated charcoal absorption EE2 characters by static absorption method. The result showed that EE2 can be removed effectively by activated carbon adsorption. Langmuir isothermal equation can describe the adsorption EE2 characters of activated charcoal well. The relativity adsorption coefficient reached marked or extremely marked level; compared with adsorption performances of different kinds of activated carbon coefficient, the adsorption capacity of PAC3# was the largest to EE2, The adsorption rate of PAC7# was the fastest, but the adsorption capacity of PAC7# was the smaller.

Abstract: According to the surface warship combat conditions, there are airspace confliction between ship-borne machine and missile, the study build a vector calculation model to describe the damage area between missile system and moved carrier machine. Proposed the Setting time method and adjusted course method, build the simulation to calculation and analysis to verify the effectiveness of the method.

Abstract: This paper proposes a trademark retrieval algorithm combining the image global features and local features. Firstly, extract pseudo Zernike moments of the retrieved image and sort them according to similarity. Candidate images are formed. Then, the SIFT features are used for matching the query image accurately with candidate images. Experimental results show that this method not only keeps high precision- recall of SIFT features and is superior than the method based on the single pseudo Zernike moments feature, but also improves effective retrieval speed compared to the single SIFT features. This method can be well applied to the trademark image retrieval system.