Papers by Keyword: Linear Distribution

Abstract: This paper mainly discusses that in mobile robot vision navigation system, by using the improved Hough transform, we can improve the accuracy of line extraction and therefore avoid the image quality reduction caused by noise points. Considering the limitations of the standard Hough transform, we come up with a method with which we will accumulates the H (ρ, θ) through distributing the increment value, set a global threshold to shun the pointless measurements, eliminate the false lines by comparing θ difference between tow arbitrary lines, find the peaks by using rectangle window, and set a local threshold to eliminate false peaks. In this way, we can gain a method superior to the standard Hough transform which works better in extracting lines in application. The experiments show that this method can not only extract line features of geometric figure effectively in brief background, but also eliminate the iterative lines efficiently.

Abstract: The basic equation of axial flow pump is derived from the assumption， which axial plane velocity and circumferential velocity distribute linearly along the blade radius. Based on the basic equation, the axial plane velocity and circumferential velocity gradient of discharge blade are calculated, and the flow field of pump is built. Using arc method of design blade, a design case is given. The standard K- epsilon turbulence model is applied to simulate the flow field of axial flow pump by FLUENT software. The simulation results indicate that pump efficiency reach 91%, there aren’t impact or vortex in pump, and the pressure distribution on the blade suction surface is even and high, the anti-cavitation performance is improved.