Advanced Materials Research Vols. 443-444

Abstract: Filament tension control system is integrated into real-time core of open-architecture winding CNC. Based on filament tension generation theory for filament wound component, the method of process elimination is applied to modify the theory of filament tension control to transform uncontrollable elastic tension to known quantity, thus improves the control precision of tension in filament composite wound components. (Abstract)

Abstract: In this paper, we propose a novel fault diagnosis method for aircraft power supply system. We constructed the Dynamic Fault Tree (DFT) of the Constant Speed Constant Frequency Alternation Current (CSCF-AC) power supply system based on the Priority Dynamic Fault Tree (PDFT). And by adding a new temporal operator BEFORE (BF) to the usual Boolean operators, we derived the structure function of the top event. Then two laws were provided to reduce this structure function to a sum-of-product canonical form, where each product term defined a minimal cut set (MCS) or a minimal cut sequence set (MCSS) of this fault tree. This approach provides a complete qualitative description of the system without resorting to the corresponding Markov model. Then a 3-layer network diagnosis system was designed and realized for the fault diagnosis of aircraft power supply, including onboard layer, ground maintenance layer and remote expert layer. This 3-layer system enhances the flow of complex fault data into higher expert layer to realize the advanced diagnosis.

Abstract: A method to extend Doppler frequency discrimination tolerance is proposed for quick acquirement PN-code and Doppler frequency in TDMA burst spread spectrum communication system. According to Doppler’s different impacts on the correlation Peak and data demodulation, PN-code is acquired through single channel matched-filters, and parallel multi-channel correlators are used in the data demodulation branch channel. Thus, with using frame head prior information in data channel instead of traditional Cross-Product Automatic Frequency Control (CPAFC), the Doppler frequency shift discrimination tolerance is extended. Simulation and experiment show that frequency and PN-code can be acquired in several data periods, and synchronous time and the resources consumption are effectively reduced.

Abstract: To ensure the fluids selected to drill and complete the well would simplify the operation for the oil and gas development in the petroleum industry, a natural vegetable gum drilling and completion fluids system is developed for the industrial intelligent application. As the system combines the advantage of the drilling fluid and completion fluid, it need not change the two different fluids during the operation, which is beneficial to the intelligent operation. In addition, the formulation of the proposed system has mainly taken the environment factor into consideration as the environmental protection has become main concern before the implementation of the oil and gas exploration. An extensive laboratory work of the natural vegetable gum drilling and completion fluids system is carried out, including the formulation study of the detailed system and the corresponding performance evaluation. In the system, the vegetable gum is chosen as raw material and TLJ-1 is optimally selected as the major treatment agent in the natural vegetable gum drilling and completion fluid system. The LV-CMC, polyglycol and QS-2 are taken as the auxiliary treatment agents for the system. And the three formulations, i. e. the solids-free fluid system, the low-solids fluid system and the weighting fluid system have been presented in this paper. The laboratory analysis has demonstrated that the prosperities of the system are proper for the industrial intellectual application, with the temperature resistance capability of 315 ℉.

Abstract: The special crane used by ship in this paper is a multi-joints and folding robot arm’s work system. Because it needs to work in a variety of sea conditions and being affected by waves and so on, the high demands of the trajectory control should be required. For this kind of complex control system, a system which is analyzed and simulated by the combination of ADAMS (Automatic Dynamic Analysis of Mechanical Systems) modeling based on a virtual prototype and MATLAB control is built and designed. The composition and implementation of the system are presented in the paper. The fuzzy cerebella model articulation controller (FCMAC) was used to tracking control and dynamic simulation research was done for this system. The results showed the superiority of this method which made kinematics and dynamics modeling analysis on ship-borne special crane based on the ADAMS. The simulation results of controller showed FCMAC had good tracking effect. The research method has intuitive, efficient and convenient features, provide better thought for similar studies of complex mechanical system.

Abstract: In order to solve the model element-missing problem of magnetic worm during the transmission process from Pro/Engineer software to ANSYS software, the paper proposes a novel transmission method. Tooth surface point-data file is established by the MATLAB software. Then the tooth surface curve is generated by the Pro/Engineer software according to the point-data file. The curve is imported into ANSYS software to set up the finite element analysis model. Finally grids are divided by the ANSYS software. After a series of programming and related works, the finite element model of the worm is established in ANSYS software and it indicates that this method is practical and effective and successfully resolved the model element-missing problem of magnetic worm during the transmission process from Pro/Engineer software to ANSYS software.

Abstract: This paper introduces the mechanical structure of a three-link direct drive SCARA for wafer handling application. The dynamic modeling of the presented SCARA is derived and the coupling effect of the system is studied. A decoupling method based on computed torque control is employed in the implementation. Robust control is applied to design the SISO controllers after the system is decoupled. The experimental test results demonstrate satisfying dynamic, settling and static performances by utilizing the decoupling robust control.

Abstract: In this paper, the mechanical behaviors of pipe roof and bolt of shallow and unsymmetrical tunnel in soft rock are analyzed. Through the finite element software Phase2.0, combined with the geological conditions that construction site often appear, the mechanical behaviors of pipe roof and bolt and surrounding rock in the process of horseshoe highway tunnel construction in the condition that surface is soft rock and underground for the bedrock are analyzed. Research results show that: after tunnel excavation in soft rock, surrounding rock near the tunnel is easy to suffer soft-rock large deformation even failure, which needs to timely support；Due to the impact of the unsymmetrical tunnel, the mechanical behaviors of surrounding rock are unsymmetrical, such as the maximum displacement of tunnel around 0.4 m distant from apex of arch ring, the stress is asymmetrical on both sides of the tunnel arch ring etc; In addition, pipe roof can effectively prevent from the displacement of soft rock strata, improve tunnel strength factor, reduce the plastic zone of surrounding rock. This paper provides theoretical basis for the design of pipe roof and bolt.

Abstract: This paper analyzed the typical power process of construction machinery, led to the idea of energy saving and the concept of generalized energy saving, put forward energy saving control system of construction machinery according to the present two typical control technologies of construction machinery. In the quantitative analysis of energy saving effect, aiming to the shortcomings of the current energy saving technology difficult to quantify, the paper puts forward a formula of the global energy saving target, explains comparison and evaluation methods of energy saving effect, and gives the concrete realization modes of the global energy saving and generalized energy saving: full electronic control technology and distributed control technology. Finally the paper prospects the future development trend of energy saving technology in construction machinery.

Abstract: Crop wet biomass measuring with dielectric spectroscopy is a non-destructive method to quickly and accurately estimate plant biomass in situ. It optimizes the management of agronomists. An electrostatic free-space system was designed and tested to estimate crop wet biomass in situ. It acts as a parallel plate capacitor. The appropriate size of plate of the system is determined through Finite element analysis (FEA). Water is used to make the exclusion of interference at the earlier stage of the experiment, and Wheat is the experiment material. Results from the measuring system showed The Susceptance through the system was strongly correlated with wet biomass. The coefficient of determination (r2) is greater than 0.9.