Ellipse
– Operating Handbook
ELLIPSEOHAIR
This operating handbook explains how to install and setup an Ellipse in airborne applications
such as aircraft, helicopter, or UAV. Mechanical installation is explained as well as software
configuration and magnetic calibration.
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Mechanical installation with alignment, vibration and magnetic field considerations
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Software configuration with motion profile, GPS antenna lever arm
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Magnetic calibration in case of magnetometers use
Mechanical installation
Inertial Systems are very sensitive to their environment and the location of the inertial system
into the aircraft is a key point to get accurate and reliable measurements.
Sensor accuracy can be greatly compromised if following instructions are not followed.
Vibrations
The Ellipse is designed to handle vibrations. Nevertheless in case of highly vibrating
environment, an efficient mechanical vibration isolation is required for proper operation. Silicon
dampers can be used for that purpose.
Ellipse placement in the aircraft
The vehicle coordinate frame is defined as follows:
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X axis points to the front of the aircraft
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Y axis points rightward.
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Z axis points downward.
The Ellipse MUST be mechanically aligned with the vehicle coordinate frame, as explained in
the following diagram. Alignment accuracy should be better than 0.5°.
Note: If a correct mechanical alignment is not possible, then a software alignment
can be used. Please refer to the Ellipse User Manual for such operation.
The main lever arm is the signed distance, expressed in the vehicle coordinate frame, FROM the
Ellipse center of measurements TO the vehicle desired measurement point. It can be used to
deport the velocity and position outputs to this specified location.
Only velocity and position outputs are affected by this main lever arm measurement.
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