POSE ESTIMATION OF A SCANNING LASER-DOPPLER VIBROMETER WITH APPLICATIONS TO THE AUTOMOTIVE INDUSTRY

A scanning laser Doppler vibrometer (SLDV) is an optical instrument th at can scan an area to measure the velocity field of structures. It ha s been widely used in the automotive industry. In some applications, t he pose (position and orientation) of the SLVD are required. First, th is paper describes two such applications. Then it presents a nonlinear regressive model for the pose determination of the SLDV with respect to a structural coordinate system. The model is derived from coordinat e transformation and the scanner model. In it, the pose is expressed b y six independent parameters: three for the translation vector and thr ee for the rotation matrix. The six parameters are estimated by using the least-squares technique. Statistical inferences about this model a re obtained by linear approximation. To determine the pose, four or mo re registration (reference) points are required. For each registration point, the structural coordinates and its corresponding input voltage s need to be known. The model has been implemented in a laser-based da ta acquisition system, which has been used for modal analysis, structu ral dynamic modifications, and noise control. (C) 1998 Society of Phot o-Optical Instrumentation Engineers. [S0091-3286(98)00705-3].