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.
Research and Realization of Micro-Capacity Metering Pump Control System Based on Step Motor
Up to now,it is difficult for the traditional micro-capacity metering pump to adjust the precision of flux to satisfy the automatization needs of controlling the flow of the modernization mass production technics.Using the step motor technology,a control system for the micro-capacity metering pump was developed at the core of THB6064H.The system sent message to the upper computer through serial communication,which made the system more easily to apply to a variety of occasions.Through testing and confirming,this system has such features as well-equipped function,easy data entry,low cost,and so on.
Phase characterisation of simulated high burn-up UO2 fuel
Abstract To determine the lattice constant variation with burn-up and the oxidation behaviour at high temperatures, simulated UO2-spent fuels with burn-ups up to 200 GWd tM−1 were prepared by cold pressing and sintering and characterised by X-ray diffraction analysis and thermogravimetry. The fcc-lattice parameter of the sintered samples determined at room temperature, showed a continuous decrease with the simulated burn-up. During oxidation the conversion of the simulated fuels to the (U,FP)4O9 and (U,FP)3O8-type phases was strongly delayed when the simulated burn-up exceeded 80 GWd tM−1. Also, at high burn-ups (>100 GWd tM−1), large fractions of the (U,FP)4O9-type phase remained untransformed to (U,FP)3O8 after prolonged exposure to air at 950–1000°C. This suggests a marked widening of the (U,FP)4O9-phase field when the amount of substituted uranium atoms exceeds values of about 8%.