Research On Displacement Compensation Technology Of Embedded Laser Self-mixing Interference Of Accelerometer

In recent decades,the laser self-mixing interferometric technique which originates from the external optical feedback effect has shown great promise in many application fields.The self-mixing interferometric system has a lot of advantages such as inherent compactness,robustness,easy to collimate,non-contact measurement.This technology has been applied to a great deal of aspects such as vibration measurement,displacement measurements and so on.The basic principle of the self-mixing interference effect has been demonstrated through the theory of standing wave and mult-ibeam interference.And the three mirror cavity model and multiple optical reflection model have been established.The optical output power and frequency has been deduced as well.The main emphasis of research is the method based on fringe count.This paper presents the operating principle and signal processing needed for the design of a reliable solid-state accelerometer(SSA)coupled self-mixing(SM)interferometric laser displacement sensor for embedded applications.Self-mixing(SM)or optical feed-back interferometry is being actively employed for displacement sensing.It is so as these sensors have traditionally needed a stationary support to guarantee an accurate target measurement.Such a situation has thus restricted the use of SM sensors for embedded applications.In order to overcome this limitation.The solid-state MEMS accelerometer measures such parasitic displacements of the laser sensor and a subsequent subtraction of these parasitic displacements from the falsified SM displacement provides the correct target displacement.Practice shows that a real-time SSA-SM sensing system can withstand stable operation,allows measuring correct target movements even when the LD based SM sensor is subject to extraneous movements.Such an approach opens the way for the use of such laser sensors in conditions where the use of anti-vibration support is not available or possible.It has a wide application prospect.