Dynamic Inertial measurements

Imego is a leading developer of high performance MEMS inertial sensors and small high performance low-weight IMU's (Inertial Measurement Units). These have delivered qualified benefits in the areas of navigation, motion tracking, stabilisation and vibration detection. Our expertise within this area was highlighted in a governmental expert commission evaluation report in 2004, as well as in official reports from the USA Department of Defence and the European Space Agency. where we are named as a possible technology supplier for current and future programs.
 

Imego has in-house expertise in all the IPR and skills required to build high-performance inertial sensors. This effort is spearheaded by two competitive sensor concepts: the “Butterfly” gyro and the 3-axis “Quad Slanted Beam” accelerometer. Both these devices can be manufactured in a robust and relatively simple bulk silicon micromachining process, which is identical for both devices.
 

Furthermore, for several years now, we have been actively developing a novel digital sensor electronics concept that eliminates 1/f noise, increases offset stability and scale factor stability and provides increased flexibility through software tunable range, resolution, bandwidth, etc. Today this concept has been realised in an ASIC that places Imego at the top of the line regarding electronics for MEMS gyros and accelerometers, several years ahead of most of the competition.
 

Imego’s digital electronics concept is also ideally suited for utilising advanced signal processing algorithms to further boost sensor performance.Model-based signal processing for sensors is an area we have researched together with Saab Bofors Dynamics for some years and it has finally come to fruition and produced commissioned work and contracts. Indeed, advances are so promising that we already have begun implementing these results in our most advanced sensor platforms.
 

Another issue essential in being able to achieve high performance, is packaging the sensors. Presently, Imego offers an effective, practical solution for the zero-level (wafers scale) packaging. We have also made significant progress in first and second level packaging, but this is an area we are actively working in to improve and refine current concepts as well as testing new concepts.
 

Imego operates a proprietary navigation engine, something that few outside the military industry can offer. This software package constitutes the base from which we can develop navigation and motion tracking applications. It is also possible to fuse additional sensor signals, as well as constraints on movement, into the software package. These constraints and additional knowledge increase the precision and prolong the useful navigation time compared to what would be the case for totally unknown six degree of freedom motion.
Another prerequisite in achieving high accuracy and long navigation times is calibration of the sensors and determination of their relative orientations. For this purpose, we have an automatic temperature controlled calibration station consisting of a rate table and all the necessary control software.
 

All INS are relative measuring instruments and must be initialised, just like a watch, to know were they are and how they are orientated from the start. In most applications, it is not possible to start from a well-defined position and orientation, therefore we have developed dynamic initiation algorithms that are capable of initialisation on the fly. An example application is presented on the next page. To summarise, Imego is a leading developer of MEMS inertial sensors, IMU’s and applications based on these components.