Abstract: A MEMS accelerometer system can include a proof mass device having a proof mass configured to move from an initial position in response to an input acceleration, a transducer operatively connected to the proof mass device to output a transducer signal correlating to a movement and/or position of the proof mass, a driver operatively connected to the proof mass device and configured to drive the proof mass, and a controller operatively connected to the driver to control the driver. The controller is operatively connected to the transducer to receive the transducer signal and output a drive signal to the driver to drive the proof mass toward an initial position. The system can include an observer module operatively connected to the controller to receive the drive signal. The observer module can be operatively connected to the transducer to receive the transducer signal.