Advanced Materials Research Vols. 430-432

Abstract: The design thought of "dual-CPU architecture" is used on the basis of a deep study of embedded systems and multi-functional CNC machine tools. That is to say, microprocessor S3C2440A of Samsung ARM9 series is used as control core, whose PWM timer produces pulse to realize the automatic control of the process. As the main control center, it plays the main functions of NC program input, keyboard entry, LCD display, the interpretation of the program, crude interpolation and so on. Using CPU as auxiliary equipment, it receives signals from master control center to realize fine interpolation through further calculation. Simultaneously the periphery of the system expands modules of human-computer interaction, communication, servo, and input/output to realize human-machine interaction, data communication and motor control. Finally, the hardware modules are debugged and the results are analyzed, which shows that the system is of fast response, reliability, low cost and good cutting and portability. This system has achieved the desired anticipation and has broad prospect in the economical CNC field which requires fast moving and proper processing speed.

Abstract: Complex terrain conditions greatly influences the movement of mobile robot,which should not be neglected.In this paper,a novel motion modeling idea is proposed, in which the robot chassis attitude angle changes caused by topographic changes was real-timely measured and be input into the robot kinematic modeling process to establish the overall kinematic model of robot. This modeling method reflect the various parts of the robot motion relations, and also display the complex topography of the robot trajectory of the end of the actuator.Finally,validated and analyzed the feasibility of the modeling method.

Abstract: To avoid the creep rupture of GFRP bar in RC members, not exceeding 20% design tensile strength (ffu)) is recommended as design limit for sustained stress level in GFRP bar in current ACI 440.1R-06 guideline. In this paper, the effects of using light weight concrete (LWC) is studied to investigate the sustained stress level in GFRP bar RC bridge decks by a parametric study. Results show that the sustained stress in GFRP bar in LWC bridge decks is in between 2.8-5.7% of ffu, while it is about 3.44-7.52% for normal weight concrete (NWC) deck.

Abstract: To solve the serious problem of the nonlinear and Time-varying uncertainty of the valve-control-cylinder system, a control system was designed with neural-proportion-integral-differential (PID) theory. Because of the capacity of neural network, the control system showed adaptive capacity in the system of valve-control-cylinder. In this paper, the basic theory of a single neural element self-adaptive PID controller and a model identifier based on Radial Basis Function were described. The mathematic model of the valve-control-cylinder control system was set up. The simulation results prove that the neural-PID system can regulate the PID parameters dynamically by self-learning so that the system with the neural-PID controller showed quick track performance and capacity against the disturbance. The results also prove the validity and applicability of the system. The algorithm is simple, PID initial parameters are easy to adjust, easy in application of the real-time control the valve-control-cylinder system.

Abstract: Anchor as a simple effective shoring form of the city is widely used in the construction of underground projects, and popularized by the underground engineering strongly. From the type, monitoring instrumentality, and method of the anchor,This paper would analyse the application of the anchor and the problems existed in the underground engineering to afford some help for the underground engineering, at the same time, it have important reference value for researching new type, construction method and the anchor monitoring method in the process of underground engineering.

Abstract: Fractal, as a new technique of signal processing, is suitable for analyzing the non-linear fault signals of rotating machine. By researching the characteristic of non-linear vibration signals of rolling bearings, a study of box dimension in analyzing the vibration signals and diagnosing the fault pattern of rolling bearings is proposed. Box dimension algorithm is presented in details and quantificational calculating of non-linear vibration signals generated by bearing system is also discussed. Experimental results show that kinematics mechanisms of rolling bearing result in the different working state, so the box dimensions are different evidently. The application of box dimension in monitoring working state is a new approach to promote the accuracy of rolling bearings.

Abstract: The traditional envelope analysis methods are usually ineffective in the fault diagnosis of Gearbox on the condition that there are multi-fault sources in mechanic systems. In the paper, an independent component analysis (ICA) approach is proposed incorporating with the envelope analysis to handle the difficulty. The gearbox envelope signal can be separated into different components according to different vibration sources, and then be further studied by the envelope spectrum analysis in terms of the vibrations in the gearbox. Extensive practical tests on the gearbox including two types of faults are performed to verify the validity of the proposed method. The test results show that the fault frequency characteristics can be separated successfully and the faults are identified precisely.

Abstract: Existing sintering machine for controlling of arch camber is not ideal. The usual way is by means of the hydraulic system to balance the excess thrust what is caused arching. For this reason, the paper considers to change the structure layout of belt sintering machine ,so that eliminate the arch camber by itself. So improvement of process layout of 60㎡ sintering machine has been made, and thus deduced the expression and got the limen formula of the thrust force which the back sprocket wheel drive lower pallet cars. At the same time, through the analysis and compute got driving moment of lower pallet cars, which caused by four pallet cars from back sprocket wheel. According to equation of mechanical equilibrium to eliminate the arch of pallet cars, determine the suitable angle after sintering machine has been improved to solve the problem about arch pallet cars completely.

Abstract: At present high-pressure sodium lamp is main lighting source of the college and university sports teaching venues. In the 2008 Beijing Olympic competition venues and the 2010 Shanghai world expo exhibition, LED lighting lamps and lanterns are adopted in large quantities because of the concept of the green, environmental protection, energy saving. Author in this paper used to be engaged in the teaching of college sports in our country, and do research about lighting source requirement in our college and university sports teaching venues, such as suitable and uniform illuminance, ideal for light color, third dimension and small glare, etc. The inquiry about the application of The LED and high pressure sodium lamp in the universities sports teaching venue is discussed in this paper, so that it can provide a reference on high-pressure sodium lamp replacement LED lighting lamps and lanterns.

Abstract: Currently the annulus pressure of gas well becomes more common, so the safe production of several wells has been seriously affected. The annulus pressure mechanism is relatively complex, and it can be approximately classified into annulus pressure induced by temperature effect, by ballooning effect and by leakage or seal failure etc. The article mainly focuses on the annulus pressure mechanism induced by ballooning effect and the corresponding calculation model. For the tubing column with two ends fixed and closed, when tubing internal pressure is larger than the external extrusion force, the external diameter of the tubing column balloons (i.e. ballooning effect). It reduces the annular volume between the tubing and the casing, and consequentially induces annulus pressure. Based on the fundamental theory of elastic-plastic mechanics, the tubing column is simplified into the thin walled cylinder so as to deduce the relation models between the internal pressure and its swell capacity and A annulus pressure value, which provide theoretical support for safety evaluation on annulus pressure and the next treatment program.