文摘
A roughness sensing system, based on the fringe projection technique, is introduced. Roughness parameters are estimated from the fringe pattern projected on the target. The system employs a new projection unit in which light, coming from a laser diode, is coupled to a fiber optic and then impinges on a diffractive optical element (DOE) to produce sinusoidal fringes. The proposed sensor is simple, small and cheap and its sensitivity is easily adjustable. Fringes generated by the DOE are analyzed by a fast fourier transform (FFT) based algorithm, which can work also on curved surfaces.