Among the various type of accelerometer, servo rebalancing type accelerometer can be available for Inertial Navigation System, because of its high sensitivity and good response in low frequency.
In this paper, we proposed a new technology to control inductive type accelerometer utilizing digital PWM method. In servo type accelerometer, controller is always nulling the pendulum in the face of external acceleration and the input current of controller is measured as acceleration. In Inertial Navigation System, some signal processing is necessary for deriving velocity, distance and other quantities. So, in order to get the accurate information such as displacement, it is necessary to measure accurately the input current. In most cases, Digital Signal Processing need digital data transmission, digital PWM method is adaptive for this purpose. We realized a practical circuit for digital PWM control, analyzed the stability of the circuit, and designed the controller etc. We applied this digital PWM controller circuit to accelerometer which has inductive type pick off. In this study, we solved many practical problem for this application, and get out good results.
