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SPEEDBOXMINI-MeasurementAccuracy / AttitudeAccuracy-INSOptionOnly

Attitude accuracy (INS option only)

SPEEDBOX MINI-INS Attitude Accuracy Test

In order to test the accuracy of our SPEEDBOX MINI INS attitude measurements (roll, pitch and yaw) the units were tested against a navigation grade RLG IMU with two military GPS receivers providing both standard GPS and GPS compass information. Additionally the reference system GPS solution was post processed with corrections gathered at a reference station, resulting in a cm-level accuracy GPS solution aiding the tactical-grade IMU. The complete reference system cost in excess of $500K.

The reference system is permanently and accurately installed in the testing vehicle for optimum measurement precision. The SPEEDBOX MINI-INS systems were additionally fitted to the vehicle ready for testing and data collection.

Open-sky high dynamics test

High dynamics tests were performed in open-sky conditions (good GPS conditions). These conditions would be applicable to many tests for which the system is intended; including stability testing, slip angle measurement and vehicle dynamics development. In a large open and clear area figure of eights were driven at a demanding pace. This test was repeated multiple times.

The headline 1-sigma comparison figures for both the standard SPEEDBOX MINI-INS and the tactical grade SPEEDBOX MINI-INS versus the reference system during this test are shown below:

Representative yaw, pitch and roll output from the standard SPEEDBOX MINI-INS is shown below compared to the reference solution.

Roll

Above: Roll output (SPEEDBOX MINI-INS Tactical Dual Antenna system compared to reference system)

Above: Roll output (SPEEDBOX MINI-INS Tactical Single Antenna system compared to reference system)

Above: Roll output (SPEEDBOX MINI-INS Standard Dual antenna system compared to reference system)

Pitch

Above: Pitch output (SPEEDBOX MINI-INS Tactical Dual antenna system compared to reference system)

Above: Pitch output (SPEEDBOX MINI-INS Tactical Single antenna system compared to reference system)

Above: Pitch output (SPEEDBOX MINI-INS Standard Dual antenna system compared to reference system)

Yaw

Above: Yaw output (SPEEDBOX MINI-INS Tactical Dual antenna system compared to reference system)

Above: Yaw output (SPEEDBOX MINI-INS Tactical Single antenna system compared to reference system)

Above: Yaw output (SPEEDBOX MINI-INS Standard Dual antenna system compared to reference system)

Error Distribution

Please note that the pitch and roll measurements are calculated in exactly the same way, and as such we would expect to see very similar error distributions for both measurements. However as can be seen below the pitch appears to significantly more accurate than the roll measurement, resulting in a double peak distribution. The reason for this is that the reference system and our SPEEDBOX MINI-INS systems are mounted at different locations on the test vehicle. As the test vehicle was driven in a figure of 8 pattern, the forces enacting on vehicle are twisting it one way, then the other; and due to this the 2 systems saw slightly different roll angles. On the pitch axis the vehicle is much stiffer and you cannot see the same effect.

Above: Distribution of difference in measurements between the SPEEDBOX MINI-INS Dual Tactical and the reference system

Above: Distribution of difference in measurements between the SPEEDBOX MINI-INS Single Tactical and the reference system

Above: Distribution of difference in measurements between the SPEEDBOX MINI-INS Dual Standard and the reference system