Real-time Accelerometer Coupled Self-Mixing Laser Displacement Sensor for Embedded Applications

Overview & Synopsis

A Solid-State Accelerometer (SSA) coupled Self-Mixing (SM) interferometric laser displacement sensor is presented that is able to provide correct measurements in real-time while being subject to extraneous movements. Such a SSA-SM sensor is thus able to correct the influence of parasitic movements that would corrupt true target motion sensing. Hence, it can be used for those embedded applications where a sensor needs to operate under non-stationary conditions. The SSA-SM sensor achieves this robustness through a real-time data fusion between the SM interferometric signal and the acceleration signal. The falsified displacement signal retrieved by processing the SM interferometric signal (representing the sum of true target movement and the extraneous movement) is thus corrected in real-time. Our SSA-SM sensor has been compared with a reference commercial sensor and it has a precision of 96 nm rms with a bandwidth of 40Hz-500Hz.