Adaptive compensation of motional disturbances for laser Doppler vibrometer

This paper presents an LDV's body vibration compensation technique which is based on the LMS adaptive processing of the auxiliary signal measured from an in-housed damper. The utilization of the in-housed damper and the adaptive signal processing significantly alleviate the problem of calibration and environmental settings for the LDV. The proposed compensation technique is implemented with the design of a prototype LDV system, assuming one dimensional body movement in the direction of measurement. To illustrate the feasibility of the technique, the operation of the designed system is tested with computer simulations as well as with experimental data actually measured from the fabricated prototype system. It is also shown that the slowly varying pattern of the environmental vibration, the assumption of which can be justified in most of practical situations, can be effectively exploited and removed from the measured signal by applying the LMS adaptive algorithm.