PRIMUS: SWAP-oriented IMUs for multiple applications

In many applications, Size, Weight and Power (SWAP) consumption are key drivers in the design of a gyrocompass. During the past decade, Safran Electronics & Defense (formerly known as Sagem) designed the Hemispherical Resonator Gyroscope (HRG), a low-size, low-weight and low-power consumption sensor with remarkable performance to achieve efficient North Finding and Keeping (NF/NK), but also navigation-based applications. Taking the most out of HRG's outstanding reliability by design, Safran is now manufacturing a whole IMU product line, based on its high-end vibrating gyro, associated with MEMS accelerometers and a miniaturized electronic board. Through a SWAP-oriented design, Primus inertial measurement units are able to fulfil the needs of a wide range of navigation applications. Indeed, navigation systems based on Primus IMUs have already demonstrated: • Sub-mil North and vertical finding accuracy, for many applications, including e.g. targeting • Sub-Metric inertial (GNSS-free) position keeping for cartography and mapping applications • State of the art accuracy for land and marine navigation systems • Easy integration into a navigator, thanks to Primus' multiple interfaces (GPS, DVL, CAN Bus, odometer, barometer …). This paper introduces the Primus IMU and presents: • An overview of Safran's work on the Hemispherical Resonator Gyroscope • Characteristics of the Primus IMU product line: a SWAP-focused architecture • Examples of applications addressed by Primus IMU.