Sensor with electrostatic pendular accelerometer and method of controlling such a sensor

A method of controlling a sensor comprising at least one electrostatic pendular accelerometer having stationary first and second electrodes that are secured to a housing and that are connected to an exciter circuit, and a third electrode that is carried by a pendulum connected to the housing so as to be movable and that is connected to a detector circuit, the method comprising the steps of:

• during two successive detection stages, exciting in alternation first one and then the other of the stationary electrodes by detection pulses in order to detect a first capacitance and a second capacitance between the movable electrode and the respective stationary electrodes;
• estimating a position of the pendulum from the detected capacitances;
• determining a servo-control error corresponding to a difference between the estimated position and a setpoint position;
• on the basis of the servo-control error, determining a command specifying whether the next detection pulse is to push or to pull the pendulum;
• calculating an acceleration that is to be measured as a function of the setpoint position and of the determined command;
• and
• during a control stage, exciting one or the other of the stationary electrodes by control pulses for servo-controlling the servo-control error to zero.