Advanced Materials Research Vols. 383-390

Abstract: The thrust fluctuation optimal design of the tubular permanent magnet linear synchronous motor is the key to sinusoidal flux density wave degree in theoretical analysis. And the paper analyses the law of different parameters on the flux density waveform. The axial magnetized linear motor is optimized. The measures which inhibited thrust fluctuation is obtained. It has guidance action in motor designing. It has practical engineering value.

Abstract: Orbit determination methods for a geostationary (GEO) satellite are introduced. In order to control or model the thrust force, a Kalman filter based on dynamic model compensation is proposed for the orbit determination of a maneuvered GEO satellite. The main idea is to use a first-order Gauss-Markov process to compensate the unmodeled or inaccurately modeled accelerations caused by orbital maneuver in Kalman filter-based orbit determination. Simulation with Chinese ground tracking network for a maneuvered GEO satellite was conducted to verify the performance of the proposed orbit determination technique. The results show that it can efficiently compensate the influence of orbital maneuver and achieve high orbit accuracy.

Abstract: In order to identify joint contact dynamic parameters of 3 DOF flexible joint manipulators, a vibration and movement coupled modeling approach of the manipulators was proposed. Combining the traveling wave approach of structure and the rotation transformation matrix of joint, the waveguide equations of mechanism were established. Considering the conditions of the general force balance and displacement boundary of each joint, vibration excitation of the system in moving states were obtained. Vibration equations were achieved according to the derived vibration torques and torsional vibration angles. The contact dynamic parameters of joint surface can be identified by using the vibration and movement coupled equation derived in this paper.

Abstract: Detailed discussion design parameters selection process of thrust density optimization about the tubular permanent magnet linear synchronous motor. Analysis of different parameters on the thrust density laws. Two different magnetization forms linear motor is optimized. The optimal design parameters value is obtained. Finally analysis and comparison of the two structural features of linear motor. The motor design guide has practical engineering value.

Abstract: This research presents a dynamic multi-robots formation navigation algorithm named multi-EKF localization algorithm, which derived from single EKF. In this algorithm, all formation members are treated as landmarks with known association. When the formation is running, the traditional EKF is used for individual robot to get its own localization, and the proposed multi-EKF is used to get the position of the whole formation. By calculating the joint probability distribution, the mean and covariance of the formation position are achieved, which is used to guide and constrain the individual robot localization adjustment. With this method, the multiple mobile robots system shows more stable and robust on formation navigation. The simulation and physical experiment results show the feasibility, efficiency and stability of the proposed algorithm.

Abstract: Wind speed forecasting is important to operation of wind power plants and power systems. To solve short term wind speed prediction problem, a radial basis functional neural network prediction model for wind speed time series based on cross iterative fuzzy clustering algorithm and regularized orthogonal least squares algorithm is proposed. First, the optimal fuzzy clustering centers of samples are computed by cross iterative fuzzy clustering algorithm. Then radial basis functional centers are optimized by regularized orthogonal least squares algorithm, and the generalized cross-validation is regarded as criteria to halt center selection. The proposed model centralizes advantages of both algorithms, and it can decrease network scale, improve generalization performance, accelerate network training speed and avoid ill-conditioning of learning problems. A case of practical wind speed time series from wind power plants verifies validity of the proposed model.

Abstract: The Programmable Logic Controller (PLC) market is mainly dominated by Omron, Schneider, NEC and other foreign manufacturers. The CPU module of their PLC products usually has two processors at PCB level. One of the processors is general-purpose processor and the other is Ladder Chart Hardware Process Unit (LPU). Based on the research of dual-core mutual exclusion, interrupt management and data consistency issues of the LEON2 of Gaisler Research, the LPU processor and LEON2 processor are integrated in a chip on mutually exclusive SOC (System On Chip) architecture. It is proved by simulation that the PLC SOC controller works steadily and efficiently.

Abstract: For the large centrifugal fan impeller, its working condition generally is bad, and its geometry generally is complex. So its displacements and stresses distribution are also complex. In this paper, we can obtain the fan impeller’s displacements and stresses distribution accurately through numerical simulation in G4-73 type centrifugal fan impeller using the finite element method software ANSYS. The calculation result shows that the maximum total displacement of the impeller is m, it occurs on the position of the half of the blade near the outlet of the impeller; and the maximum equivalent stress of the impeller is 193 MPa, it occurs on the contacted position of the blade and the shroud near inlet of the impeller. Furthermore, check the impeller strength, the result shows that the strength of the impeller can meet the requirement.

Abstract: The paper designed a portable intelligent gas monitor system that installed mine staff cloth for convinence and timeliness, avoiding mine accidents. The design laid emphasis on Resistance-type micro Gas sensor working normally and Sunplus single-chip microcomputer that characterised with speech in hardware. In the same time, Varing gas concentration could lead to varying speech output in software.The simulation shows the design is practical and achieving the schemed requirements.

Abstract: The finite element model of drive axle housing was built by using the solid element and the shell element respectively. Vertical bend strength and stiffness under 2.5 times of fully load of the drive axle housing were calculated by finite element method. By comparing the results of the vertical bend strength and stiffness of both models, we could know that both of the two models can be used to analyze the whole stress situation of drive axle housing. Because there were fewer elements of drive axle housing model based on shell element, the amount of final calculation was less. It is more feasible to analyze the whole stress situation of drive axle housing by establishing drive axle housing based on shell element.