ESA GNC Conference Papers Repository

SAGEM DS is Europe’s leading manufacturer of inertial navigation and provider of space solutions for 30 years. In 2005 at GNC meeting, SAGEM DS announced the release of a new IMU for space application: REGYS 20, which is based on Hemispherical Resonator Gyro (HRG) technology. HRG (Fig. 1) is a vibrating mechanical gyro that has a very high Q factor (> 10 000 000) compared with other classical vibrating gyro (~15 000). As a consequence, the forces necessary to sustain the amplitude of vibration are very low and the generated drift is then low. The philosophy of REGYS 20 development is to provide a medium performance class IMU using a reliable sensor currently mass produced by SAGEM DS for military systems. A specific hardened electronics is developed by SYDERAL, a Switzerland company. Electronics has to be as cheap as possible, matching with the required performances, in order to be able to provide a competitive IMU system. A specific ASIC is currently developed by ATMEL. In this paper, main principles of HRG technology are recalled along with some analysis of the main performance drivers such as phase shifts and gain errors. The development of REGYS 20 in the frame of Alphabus program is updated. Finally, we present the performance measurement obtained during integration phase with engineering models, particularly bias stability, scale factor stability, angular noise and angular random walk.