Wet Welding Platform Design based on Ultrasonic Sensor
The research platform for underwater wet welding is designed and high frequency ultrasonic sensor is put into use, The research platform comprises four independently movable shafts which names as X, Y, Z and A axis, The four axes are driven by servo motor and stepping motor, The features of both servo motor and stepping motor are analyzed at first, and then the relationship between the moving speed and controlling precision among different shaft is discussed, control program is given out based on ADT8940A1 PCI four-shaft bus control card after the shafts running parameters have determined, With the help of high-frequency underwater ultrasonic sensor, high-precision ranging experiments are carried out on the base of a hybrid digital signal process method combined band filter and Wavelet transform (WT), satisfied results are achieved in distance detection experiments with related coefficients method, results will be used in seaming tracking later.
The Design of Ultrasonic Distance-Measuring System Used on Car-backing System
An personally designed ultrasonic distance-measuring system is introduced and its hardware circuits and software design methods are given in this paper,which bases on Cygnal 8051 F330 single chip,and is applied to carbacking system.In the system,some improvement on both hardware and software is adapted,which makes the system has better precision and wider measuring range.Moreover,besides its capability of satisfy the requirement raised by car-backing system,the system has other characters such as briefness,economy,actual effect,practicality etc..The practical debugging results and error analyzing results are given at the end of this paper.
A model for predicting heat transfer through gypsum‐board/wood‐stud walls exposed to fire
To facilitate the development of cost-effective and flexible design options there is a need to develop models to predict the fire resistance of wood-frame building assemblies. Such assemblies often derive much of their fire resistance from a protective membrane composed of gypsum board. A simple two-dimensional computer model is presented to predict heat transfer through gypsum-board/wood-stud walls exposed to fire. Input data for the thermophysical properties of gypsum board were measured exploying standard bench-scale tests. Input data for wood were selected from the literature. Small-and full-scale fire resistance tests were conducted on gypsum-board/wood-stud wall assemblies to provide data for the validation of the model. The model is shown to predict heat transfer through these walls rather well.