Fraunhofer Institute for Electronic Nano Systems
Fraunhofer Institute for Electronic Nano Systems

HERMES – Ultra-precise inertial reference system based on MEMS gyroscopes with self-calibration algorithms

© Roman Forke/Fraunhofer ENAS
Design of a first LITEF ring gyroscope. The chip's side length is about 7 × 7 mm.

Problem statement:

In the emerging Advanced Air Mobility (AAM), the ability to automatically land and fly is becoming increasingly important. New aircraft concepts require very accurate velocity and position information with high integrity. This information must also be available after a satellite navigation failure. Therefore, inertial sensors with high accuracy are increasingly important. Beyond sensor performance, the size and weight of navigation systems are decisive. MEMS-based sensing with Inertial Reference System (IRS) performance can make a significant contribution. For this, the performance of the gyroscopes must be significantly improved.

 

Project goal:

The project builds on existing LITEF systems, which significantly shape the state of the art for inertial navigation systems. An optical-fiber system achieves IRS-class performance through GNSS augmentation. Its further development would, however, not lead to the desired reduction in volume and weight.

Therefore, the focus is on the development and clear performance enhancement of a MEMS-based AHRS system. To achieve this improvement, the currently asymmetric MEMS gyroscope must be replaced by symmetric gyroscopes. There is a need to improve the sensor design and MEMS technology to increase long-term stability and, in particular, to eliminate asymmetric error influences.

 

Implementation:

To this end, the partners address the following focus areas: symmetric design with novel quadrature compensation and reduced thermoelastic damping, MEMS technology with a very large aspect ratio, compact symmetric encapsulation with minimized parasitic capacitances and minimal internal pressure, very high and long-term stable oscillation quality factors (Q). The development of the symmetric and optimal MEMS alone is not sufficient. It is also important that the gyroscope has the ability to estimate and calibrate its errors itself. For this purpose, routines for self-calibration are developed and demonstrated on laboratory test setups.

 

Our project partners:

  • Northrop Grumman LITEF GmbH (to the website)
  • Zentrum für Mikro- und Nanotechnologien (ZfM) of Chemnitz University of technology (to the website)

Project duration: 01.03.2026 bis 31.05.2029