Are MEMS Coming of Age?
As GPS vulnerabilities to intentional jamming and unintentional interference become key factors for high-reliability navigation, inertial aiding to coast through outages becomes an important consideration for OEM integrators. Micro-electro-mechnical systems (MEMS) have been seen as offering the most promising, economical way forward for cost-effective, compact inertial and gyro solutions for almost every application going.
However, in the past, MEMS gyro and accelerometer components from which inertial and gyro systems are built have not provided performance anywhere near as good as laser gyros (ring laser gyros, or RLG) used in the majority of high-performance inertial systems. Now, as new MEMS inertial systems have begun to hit the market in recent months, the envelope appears to be opening up on achieving pretty high performance.
Gladiator Technologies, based in Snoqualmie near Seattle, Washington, is one of several companies currently supplying MEMS-based inertial/gyro systems for a wide range of applications. I came across Gladiator at the Association for Unmanned Vehicle Systems International (AUVSI) convention in Washington, D.C., last August and decided to take a closer look at them as a typical supplier of new, compact, cost-effective MEMS navigation devices, which are becoming essential compliments to GNSS.
Gladiator has been around since 2005 and has continued to innovate each year, growing its product line and gradually improving performance. Right or wrong, as an “inertial layman” I’ve always used drift rates (bias) to assess inertial accuracy, and this is apparently directly related to the noise floor of the sensor device. Now Gladiator has released its latest Landmark 50 INS/GPS with low noise MEMS gyros and accelerometers and it claims 1 degree/hour drift rate in-run — as good as an 8-cm path length ring-laser gyro — something of an achievement for a MEMS-based device. (That’s a 2 Euro coin used in the photo for size reference.)
The product line goes all the way from automotive gyros up to the latest high-performance GPS/INS, and includes basic angular rate sensors and accelerometer packages. Applications include automotive testing, agricultural motion sensing, motorsport racing, instrumentation (including robotics and flight testing), rail, marine and energy motion detection, military land-vehicle and marine platform stabilization and navigation, electro-optical/infra-red targeting and stabilization, launcher and missile stabilization/navigation, and unmanned vehicles.
Gladiator integrates u-blox GPS receivers in its GPS/INS systems because of good environmental and test performance and good accuracy and navigation update rates. It’s possible in the future that airborne-qualified GPS or higher performance DGPS will find their way into new inertial variants, but for now Gladiator is very satisfied with u-blox receivers.
Applications may use a single/dual axis gyro or inertial measurement unit (IMU) where angular attitude outputs are required, such as image, attitude or weapons stabilization, or even packaged accelerometers.
And, of course, unmanned aerial vehicles (UAVs) are one of the target markets for these MEMS products — Gladiator has already had a lot of success in this segment. Its equipment is used on a number of unmanned vehicles, including fixed-wing and vertical take-off and landing (VTOL) vehicles, as well as ground and underwater unmanned vehicles. These applications range from primary navigation/backup navigation to primary flight control/backup flight control, and include a large number of stabilization applications including electro-optical/infrared, LIDAR (light detection and ranging) and platform stabilization. Gladiator supplies these UAV applications with various inertial sensors (gyros) and inertial systems, including IMUs, vertical gyros (VGs), attitude heading reference systems (AHRS) and GPS-aided inertial systems. Customers in this market segment include Schiebel, U.S. Army, U.S. Naval Research Laboratory, ST Aerospace, and others.
Gladiator is closely monitoring progress towards UAVs gaining certified access to civil aerospace, and the prospect of expanding civilian applications and markets that that will bring. The company feels that its skills are in and around inertial sensor technology and products, and its efforts towards civil qualification should focus on these elements. Therefore, Gladiator is are looking for a partner who would take on GNSS civil qualification for civil airborne GNSS/INS applications.
Gladiator is still a small outfit with around 30 people, with most of its engineering done in-house by a team of nine engineering staff supported by some external consultants. Senior management has more than 100 years’ experience in this field, and Rand Hulsing, the chief scientist, holds 68 patents in MEMS inertial sensors. New patents are currently pending on inertial-grade gyro and accelerometer designs. People on staff have gained significant experience working for companies such as Allied Signal, Sundstrand, Honeywell, L3, Systron Donner and Hughes.
I pressed Mark Chamberlain, Gladiator CEO, for details of which (bought out) OEM MEMS devices his company integrates into its systems, and I was quite surprised by his response — Gladiator designs its own high-performance MEMS gyros and accelerometers and uses a fabless model to produce them. Clearly, it is having great success with this approach as its product performance has improved to almost within reach of existing technology high-performance inertial systems. Some of Gladiator’s lower end systems do still use OEM MEMS sensors. Their manufacturing facility in Washington focuses on product assembly and test, including calibration and environmental test.
The systems Gladiator supplies are non-ITAR — which is short for saying that they can be exported to most friendly countries, and are not subject to special/restricted U.S. State-Department trade regulations.
Gladiator does around $10 million/year currently, and anticipate its growth to continue. It has a number of sales representatives in North America, South America, Europe, Asia and Australia, so it is well known around the world, with more than 200 customers in 30 countries. I asked Mark about the possibility of an Initial Public Offering (IPO), but he is currently quite happy with the existing private ownership for the time being. The Gladiator board includes investor-directors from France and Germany, and the external directors also have impressive experience, so presumably board guidance has also helped Gladiator get where it is today.
So, we have almost-inertial high-performance products with integrated GPS, attitude-only products and accelerometer packages for almost any application you could imagine, and are quietly inching towards 1 deg/hour total within the next few years — MEMS devices really have come a long way in the last few years.
Tony Murfin
GNSS Aerospace
Follow Us