Optimization of image synthesis for complex geometry objects in the robotic ultrasonic system
This paper is devoted to the optimization of image synthesis for complex shape objects in the robotic system of ultrasonic testing. The basis of this process is a preliminary analysis of the object with complex geometry to ensure reproducibility and accuracy of the tests in the specified range. It includes such stages as digital model creation, geometric surface analysis, creating of control points and vectors, searching for optimal model location, model verification on reachability, collisions and singularity.
INDUSTRIAL APPLICATION OF REAL-TIME 3 D IMAGING BY SAMPLING PHASED ARRAY
The “Sampling Phased Array” technique compared with the conventional phased array approach became very popular in the last years making use of the propagation of elementary waves (Huygens principle) generated by individual elements of the sensor array to reconstruct the composite phased array signal by high-speed numerical computation for any arbitrary, individual angle or physically possible focus depth. As the near field of each individual transducer in the array is that of a ‘quasi’ point source, transducer-near inspection regions are much better to inspect than in the conventional case where the near field is determined by the full aperture of the transducer array. Furthermore, the special IZFP-approach allows a very fast 3-dimensional visualization of inspection objects by combining slice by slice 2dimensionally calculated SAFT-B-images to a 3-dimensional data-cube with a manifold of possible data projections for evaluation and analysis of the inspection results. 3-D-SAFT algorithms taking into account also a modified transducer design with a wide-angular sound beam characteristic in each space direction are under development.
Experimental study of water fluxes in a residential area: 2. Road infiltration, runoff and evaporation
Lack of accurate data has led some hydrologists and city planners to assume that urban infiltration is zero and runoff is 100% of the rainfall. These assumptions lead to an over estimation of road runoff volume and an underestimation of direct recharge to groundwater, which is already rising under some UK cities. This study investigates infiltration and runoff processes and quantifies the percentage of rainfall that contributes to storm drainage, and that which infiltrates through different types of road surface. Access tubes were installed for measuring soil water content using a neutron probe in three car parks, a road and a grass site at the Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford. Storm drainage was recorded at the exit of the Thamesmead Estate in Crowmarsh Gifford, just before the drain joins the River Thames at Wallingford. Rainfall and water table depth were also recorded. Weekly measurements of soil moisture content indicated that the top 40 cm layer is not influenced by water‐table fluctuations and, therefore, positive changes in soil moisture could be attributed to infiltration of rainfall through the surface. Depending on the nature of the surface, subsurface layers, level of traffic, etc., between 6 and 9% of rainfall was found to infiltrate through the road surfaces studied. The storm drainage generated by road runoff revealed a flow pattern similar to that of the receiving watercourse (River Thames) and increased with the increase of infiltration and soil water content below the road surface. The ratio of runoff to rainfall was 0·7, 0·9 and 0·5 for annual, winter (October–March) and summer (April–September) respectively. As the results of the infiltration indicated that 6 to 9% of annual rainfall infiltrates through the road surface, this means that evaporation represents, 21–24% of annual rainfall, with more evaporation taking place during summer than winter. Copyright © 2003 John Wiley & Sons, Ltd.