Advanced Materials Research Vols. 301-303

Abstract: BDCM/ LBDCM driven systems include both the electrical and mechanical parts. So there is a gap for students of electrical engineering background to learn about the subject, even though there have been so many activities (e.g. simulations and experiments) to assist their learning. In this paper, we proposed the whole-circuit models to overcome the difficulty. Since the EE department students are good at circuit analysis, such whole-circuit models will be a good medium for them to solve problems regarding electro-mechanical interactions. For example, the model can be used to modify the torsional mode frequencies tested offline by taking into account the influence of electrical power systems.

Abstract: This paper uses ANSYS 10.0 software to analyze and calculate electromagnetic field of the Permanent Magnet Synchronous Generator(PMSG). Verify rationality of magnetic circuit by the results of magnetic flux density and magnetic field intensity; optimize shape of permanent magnet and reduce harmonics quantity by air-gap flux density harmonics analysis, and use value to solve Electromotive Force(EMF). The simulation result proves that the model satisfies the design requirements and can provide theoretical guide for the optimization design of PMSG.

Abstract: The calibration of the internal and external parameters of each camera is a crucial step for free-form surface measurement based on stereo vision. The nonlinear optimization method of bundle adjustment is usually used in the camera calibration. The model of bundle adjustment can be derived from the nonlinear collinearity equations which contains the nonlinear distortions of camera lens. As the internal parameters of camera, the distortion parameters are implied in the projective transformation matrix, and difficult to be explicitly expressed by an equation. But the establishment of the model of bundle adjustment needs to calculate the first-order partial derivative of each parameter. At present, there is no effective method to decompose the implicit parameters which are taken as a whole in the expansion of first-order partial derivative. The existing bundle adjustment models are not comprehensive and easy to cause ill-conditioned matrix problems. In this paper, we discuss the methods of the nonlinear camera lens distortion correction, establish a new lens distortion expression, and propose a new model of bundle adjustment based on the new distortion expression. Experiments results indicate that the new bundle adjustment model can obtain high camera calibration accuracy, and avoid the ill-conditioned matrix problems.

Abstract: We propose a scheme for realizing quantum three-qubit phase gate operation, in a three-mode cavity where the large detuned cavity-mode fields interact with the four-level artificial atom of an rf-SQUID in tripod-type configuration. In this scheme, the two lowest levels of the artificial atom represent the two logical states of the target qubit and two cavity-mode states are the control qubits, while the third cavity-mode field serves the gate manipulation. Since only the metastable lower levels are involved in the gate operations, the gate is insensitive to the decay rates of the artificial atom, which makes this scheme advantageous and it is important in view of decoherence.

Abstract: In this paper, we design a super-stable optical interferometer with multi-pass. By using single photon to estimate an unknown phase, our scheme enables considerable high precision and it can beat the standard quantum limit.

Abstract: In the automatic control system of industrial field, the production process monitoring and control process is dependent on Mutual coordination of various automation instrument, computer and corresponding actuators. The coordination is accurate or not, the key is signal transmission quality among those agencies. The application and selection of isolation device directly affect signal transmission. This paper discusses the application and choose of industrial site isolator from isolation principle, the principle and choose for isolator, commissioning and parameter selection based on practical application.

Abstract: Interferogram processing is one of main techniques in optical interferometry metrology. Modern interferometry for thin-film thickness has the advantages of noncontact and high accuracy, etc. Interferogram processing is important Step of interferometry. This article is the sum-up about the key technology of interferogram processing in interferometry, it reduce key technology of interferogram processing to three steps: removing the noise, edge detection, region spreading and phase unwrapping. Interferogram processing can be realized by using software developed by the key technologies. Then getting surface of the measured material object, thus the measured material object is measured automatically. In this paper, the thin-film thickness is determined by the key technologies, setting the results of this method against results from ZYGO, the PV error and RMS maximum error are 0.0364λ and 0.002λ respectively. Although single interferogram was processed in this study, a phase distribution with high accuracy was achieved.

Abstract: The static stability of missile pitching movement is one of the important performances in guidance and control systems. In this paper, a method which consists of the single and double loop longitudinal autopilot using frequency domain approach is proposed to solve the problem efficiently. Single-loop autopilot is used to simplify the system design when the missile is highly static stable; the double-loop autopilot is employed to stabilize the system and improve frequency performance when the missile is static stable or static unstable. Control gain of the system is determined by aerodynamic parameters and frequency domain indexes. The simulation result shows that double-loop autopilot based on frequency domain simplified the system design and improved the stability and robustness of missile system.

Abstract: In practical application, some flowmeters are not allowed to be calibrated off-line periodically, thus on-line calibration is necessary to be implemented in workplace [1]. As a non-invasive flowmeter, the clamp-on ultrasonic flowmeters are widely used in on-line calibration system. As a master flowmeter, ultrasonic flowmeters must be calibrated before or during using. Based on multiple fieldbus control system, an automatic calibration system for the ultrasonic flowmeter was designed. The comparison results between ultrasonic and electromagnetic flowmeter obtained during the process of calibrating manifest that the automatic calibration system is effective and reliable. Because of the good interoperability of the multiple fieldbus, other flowmeters with different protocols can be connected into this system easily. With the high speed development of fieldbus technology, this has great practical significance in flowmeter calibration.

Abstract: Icing on blade surface of the wind turbine set in cold regions is a serious problem. To invest the mechanism of icing and ice accretion on blade surface, wind tunnel tests were carried out on a static straight blade used for the straight-bladed vertical axis wind turbine by using an icing wind tunnel. The icing and ice accretions on blade surface at some typical angles of attack were observed and recorded in a fixed wind speed and steady flow discharge. The mass of ice accretions on the surface of blade were also measured and compared. At the same time, the drag and lift coefficients were tested by a three-component force balance. Based on the test results, the factors affecting the mass and characteristic of ice accretions and the drag and lift coefficients of the straight blade were discussed.