| 摘要 |
PURPOSE:To shorten a position spotting time by storing time differences between respective meshes in a spotting area and the 1st and the 2nd couples of impact sound detection points in respective meshes, generating the 1st and the 2nd time difference maps, and superposing them one over another. CONSTITUTION:For example, an impact sound is generated in the spotting area A on the surface of metal, the detection time difference DELTAt1 between both impact sound detectors Da and Db arranged at detection points (a) and (b) is calculated from both detectors Da and Db, and this time difference DELTAt1 is marked in all corresponding meshes on a time difference map 1. Thus, one hyperbola is obtained. Further, this impact sound is detected by impact sound detectors De and Dd arranged at detection points (c) and (d) to calculate the detection time difference DELTAt2 between both detectors De and Dd, and this time difference DELTAt2 is marked in all corresponding meshes on a time difference map 2. Then, another hyperbola is obtained. The hyperbolas obtained on the time difference maps 1 and 2 are superposed to obtain their intersection, which is then spotted as the impact sound generation position. |
