Transient responses and stability in the differential electrostatic sensor of inertial and gravitational moments with asymmetry

High sensitivity of Gravity Inertial Sensors (GIS) can be achieved with low natural frequency Ω of the proof mass (PM) that must have low level noises in the read-out system and a minimized torsion stiffness. In this article, a differential electrostatic system (DES) is proposed where both previous two conditions are met. We also consider the effect of the asymmetry γ of the DES in the GIS that is limited by the manufacturing technology of the sensor and hence making it difficult to reduce further. We propose an alternative compensation of this asymmetry by introducing additional sources of electric field. It is shown that any inaccuracy in this compensation will lead to inaccuracy of the sensor and can violates it stability. Based on open public literature, this is the first time where it is possible to ascertain the torsion stiffness reduction limits for such a sensor.