Analog sensor design proposal for laser Doppler velocimetry

Laser Doppler velocimetry (LDV) has been widely used for many years in fluid mechanics to measure particle velocity. However, in most applications, i.e., in industrial processes, such a system is often too expensive. This paper discusses a technique based on the use of an analog phase-locked loop and an analog integrator system for processing laser Doppler velocimeter data to infer particle velocity. This method appears to be suitable for designing low-cost integrated LDV sensors. A SIMULINK program has been written in order to validate the method for velocities in the 10-80 mm/s range. Finally, the performance of the estimator is illustrated by Monte-Carlo simulations obtained from synthesized Doppler signal.