Shock immunity enhancement via resonance damping in gyroscopes for automotive applications

This paper presents an innovative and effective method to improve the performance of a micro mechanical gyroscope by introducing the damping of its sensing quality factor. Indeed the sensing quality factor is a key parameter for the micro mechanical gyroscope dynamic; particularly high sensing quality factor means long settling time, high response overshoot and high sensitivity to external disturbances (shocks and vibrations) that are typical of harsh automotive environment. For this reason micro mechanical gyroscopes employed in automotive environment need high shock and vibration immunity. This paper proposes a solution to reach this goal by adding a ldquovirtual dampingrdquo to the system with an electrostatic feedback technique. This approach has been applied to a real automotive yaw gyro system, and simulations performed using Simulinktrade environment show an appreciable output overshoot reduction, with the benefit of higher vibration immunity, once implemented the feedback technique.