Advanced Materials Research Vols. 328-330

Abstract: As people’s living pace becoming faster and faster in modern society, a lot of machines which can substitute human beings, such as washing machine, dishwasher, have appeared. These machines can greatly save people the necessary labor times. The automatic cleaning wall mechanism which is studied in this paper belongs to a category of cleaning machine. It aims to clean the body cavity wall of a square. The primary research includes the mechanical structure design, the electrical control system design, and modal analysis for this mechanism in order to avoid resonance phenomena occurred between motors and bodies. At last, via experimental running, this mechanism can move forward according to our predetermined trajectory.

Abstract: In this paper, a novel blind separation approach using wavelet and cross-wavelet is presented. This method extends the separate technology from time-frequency domain to time-scale domain. The simulation showed that this method is suitable for dealing with non-stationary signal.

Abstract: In this work, according to the nonlinear re-radiation characteristic of semiconductor PN junction, the nonlinear junction detection system for semiconductor junction targets based on second harmonic reception is designed on the basis of the analysis for nonlinear re-radiation characteristics of semiconductor junction targets, derivation of the system implementation scheme. By the system simulation and experiment, the preliminary test results show that the system can detect well the junction of nonlinear component with gain high enough for signal detection.

Abstract: The paper takes robotics remote sensing as research background. Robotics remote sensing is a newly developed research area. Compared with traditional remote sensing and robotics technology, definition of robotics remote sensing is discussed in the first part. In the second part, the paper combines the latest international and domestic research references and practical robotics application platform. It mainly studies robotics remote sensing on eight-wheeled robot RAT-1 for mine sensing, mobile robot with IR-optical sensor for gas leak detection and source localization, ambient intelligent robot for environmental surveillance, mobile robot for object localization and other hot research points. Because of its new appearance, studies of robotics remote sensing are not matured. So the paper also indicates key problems existed in each application and predicts three most possible development aspects of robotics remote sensing at last.

Abstract: The control of amplitude of limit cycle emerging from the Hopf bifurcation in Chua system under a nonlinear feedback controller is investigated in this paper, Explicit nonlinear control formulae and amplitude approximations in terms of control gains derived from the center manifold theory and normal form reduction present a convenient approach to obtain an effective analytical control and predict the amplitude of limit cycles in Chua system. The calculating simulations indicate that the approximate solutions are in good agreement with the numerical solutions.

Abstract: This paper presented a visible measurement method of dispersion spot at a four-quadrant detector based on digital image processing according to the problem of big measurement error and low efficiency in the existing production process used by the indirect measurement method of dispersion spot based on four-quadrant detector output signal. This method designed a visible measurement optical system and established a visible measurement mathematical model of four-quadrant detector dispersion spot, obtained the four-quadrant detector photosensitive surface and dispersion spot geometrical coordinates and size through digital image processing for the four-quadrant detector photosensitive surface and the dispersion spot, then got the adjustive parameter of out-of-focus distance automatically. The results of the experiment show that this method is intuitive and simple, measurement accuracy is improved from 0.02mm to 0.004mm and the measurement time is reduced from 15 minutes to 2 minutes.

Abstract: A data collection terminal for performance testing of non-continuous signal of the automotive camshaft sensor is designed, Using NI-6259 data acquisition card to connect the data of collection terminal with pc, and composed of a complete monitoring system of performance testing of automotive sensor. The system can display the maximum, minimum, average, duty cycle, frequency and frequency multiplication or not of the high level and low level in real-time. And the frequency range of the measured signal is between 1Hz and 8KHz. Compare measured data with standard data, determine automatically whether it is reasonable and save them according to their classification. The test personnel are avoided to test continuously and monitor in real-time, offsetting the lack of single function of the display of test platform and running short of features of analysis and judgment.

Abstract: Against the shortcomings of slow convergence and large residual error in norm decision feedback blind equalization, double error function decision feedback blind equalization algorithm based on orthogonal wavelet transform momentum (WT-DMCMA-DFE)was proposed. In the algorithm, the four combinations of two error functions, respectively, to make adjustments on the former right and the feedback right, and add momentum algorithm to the former right and the feedback right to accelerate the convergence rate, escape correlation by using the orthogonal wavelet transform and normalize the energy to further improve performance of the convergence. Underwater acoustic channel simulation results show that convergence performance and mean square error of WT-MCMA-DFE, WT-H-HMCMA-DFE, WT-H-CMCMA-DFE is different.

Abstract: In this article, one new non-contact displacement sensor and its principle has been introduced; it is based upon improved Foucault focus detection and equipped with diffraction grating measuring system. Driven by piezoelectric actuator instead of voice coil motor and diffraction grating metrology system being adopted, the non-contact displacement sensor avoids non-linear error and other measurement error caused by the movement of the voice coil motor and therefore has higher measurement accuracy, which has be proved by series of experiments. During measuring the workpiece surface contour profiles, piezoelectric actuator drives focus object lens to make vertical displacement, and ensures focus in every sampling interval to go to the workpiece surface. In the mean time the focus error signal can be set to zero. The sensor has large range and high resolution, which can be applied in profile measurement. This non-contact displacement sensor resolution can reach 10nm.

Abstract: A simple dynamics model is established based on the two-link flexible manipulator moving within the vertical plane, and a robust simple control scheme is put forward. The advantages of this scheme are simple and good robustness. Only the error signal is needed when designing the control scheme and the acquirement of control signal does not depend on the system model. The simulation results show that this method has a good robustness and stability.