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.
Feature extraction and image processing for underwater weld with laser vision
Automation and intelligence are the development direction for underwater welding,and real-time sensing and detecting of underwater weld position is a key technology,among which laser vision sensing is a good-prospect detecting method.Noise features of weld image under different water environment and underwater V-groove weld image pre-processing are discussed.And both the application of mean shift algorithms on underwater weld image segmentation and linear Hough transform on extracting image features of underwater weld are studied.Experiment results show,after image enhancement and filtering,laser stripe including weld features could be effectively segmented with mean shift algorithms,and linear Hough transform was suited for precisely extracting V-groove weld feature points on the basis of thinning images.
The Diminishing Role of Social Work Administrators in Social Service Agencies
ABSTRACT The social service industry in the United States has experienced tremendous growth and change since the early 1970s. Unfortunately, the social work profession has not kept up with this growth and change. This article explores several issues that have emerged in social work administration that may contribute to the seemingly diminished role of social workers in administrative positions in social service agencies. They include the role that schools of social work play in educating social workers for administration, competition for administrative positions in social service agencies, and the differences which exist between administration in social service agencies and other types of organizations.