Ellipse-N, the INS/GNSS used by AMZ for Racing Driverless Car

IMU and GPS, Core Parts of the Driverless Car

For the first time ever, Formula Student Germany introduced a driverless category, where race cars had to be adapted to drive without any human intervention. AMZ decided to take the challenge, and prepared “flüela”, their car used for competition from 2015, to be driverless. For the AMZ team, when designing a driverless vehicle, the IMU and the GPS are a core part of the sensor suite.

Image of a AMZ race car "flüela" Photo credit: Thomas Meier — AMZ race car “flüela” Photo credit: Thomas Meier

Ellipse-N, the INS/GNSS used by AMZ Racing

Lightweight and small, SBG Ellipse2-N is the most accurate of its category, and the easier to interface with, according to the AMZ team.The team was also amazed by the quality of the output position data. The Ellipse2-N fuses inertial data and position information for a continuous trajectory even in case of GNSS outage.

Used in Very Tough Conditions

AMZ Racing Success

The team managed to be:

first in skidpad (ability to turn at steady state as fast as possible)
first in trackdrive (race in an unknown track marked with cones),
second in acceleration (measures the ability of the car to accelerate fast).

The overall event includes static disciplines in which the team also obtained good results: first in engineering design and cost, second in autonomous design and third in business plan presentation.

Image of when AMZ reached the podium in each of the eight disciplines, and won five of them. Photo credit: Christian Kreutzmann — AMZ reached the podium in each of the eight disciplines, and won five of them. Photo credit: Christian Kreutzmann

We were amazed by the quality of the gyroscopes. No one in our team neither in our university could believe the little drift we were experiencing

Mr. De la Iglesia Valls

Ellipse-N, the rugged miniature INS/GNSS

The SBG Ellipse2-N offers a 0.1° Roll and Pitch, 0.5° GPS-based Heading and a meter-level GNSS position (GPS + GLONASS constellations in this case). “We were amazed by the quality of the gyroscopes.

No one in our team neither in our university could believe the little drift we were experiencing” states Mr. De la Iglesia Valls. The team was also amazed by the quality of the output position data. The Ellipse2-N integrates a GNSS receiver and fuses inertial data and position information in real-time for a continuous trajectory even in case of GNSS outage.

Additional algorithms have also been developed for land applications to improve even further the inertial sensor performance and robustness. Robustness is one of those things that you only notice when it is not there.

According to the AMZ team, it was a tough testing season with very hot days, extremely rainy days, a lot of vibrations, mounting, unmounting, plugging, unplugging. The sensor never failed. This reliability is also due to the extensive factory calibration. Every SBG inertial sensor is calibrated in dynamics and temperature; the Ellipse2-N gyroscopes, accelerometers and magnetometers bias are corrected and calibrated from -40° to 80°C for a constant behavior in every condition.