Measurement Method for Evaluating Normal Direction of Surface for Digital Drilling and Riveting

A method of noncontact laser distance measurement is proposed for the digital drilling and riveting of complex surface. By means of measurement resulting from locating devices, the normal direction of measured region on curved surface is evaluated. The posture of end-effector fixed on the end of industrial robot is adjusted to feed along the evaluated normal direction. The datum plane for calibration is derived using the least square plane fitting method. The position and posture of locating devices are calibrated on the basis of the distances between locating devices and datum plane. The normal direction of measured area is derived from the distances measured by locating devices. A numerical example illustrates the correctness of the proposed method. The method can be used for positioning and attitude-adjusting for digital manufacturing and assembly.