Drive Testing Best Practices

Please review these best practices prior to drive testing.

Note that the EVK and Ground INS algorithms are optimized for wheeled land vehicles. For support on other vehicle types, please contact support@anellophotonics.com.

Vehicle Configurations

It is important to ensure the lever arms are set properly prior to drive testing. If you are using dual antenna in your setup, this includes an accurate antenna baseline calibration.

For more information, please refer to Vehicle Configurations.

Odometer Input

For extended GNSS-denied testing, it is strongly recommended to add odometer input to the ANELLO EVK or Ground INS to minimize error, particularly in distance traveled.

Initialization

There are a couple important notes to optimize the performance of your ANELLO EVK.

Heading Initialization

Heading can be initialized in one of two ways:

Using GNSS velocity heading (while moving). This requires driving forwards at speeds of > 2 m/s (> 5 mph) for about 30 seconds. The faster you drive, the better tuned the GNSS velocity heading will be.
Using dual antenna heading (while stationary). This requires an antenna separation of at least 0.6 meters, and accurate antenna baseline calibration (see Vehicle Configurations).

Direction Initialization

At the start of the drive, if the heading has not been initialized using dual antenna heading and odometer input with directionality is not provided to the unit, the algorithm currently assumes the vehicle direction is forwards.

To support forward and backward initialization, ANELLO recommends one of the following:

Provide odometer input to indicate forwards/backwards speeds
Ensure dual antenna heading is initialized prior to vehicle movement

Filter Initialization

The Kalman filter typically converges within 2-5 minutes of driving. The faster the driving, and the more dynamics the vehicle experiences (e.g. left and right turns), the faster the filter converges.

For GPS-denied testing, we recommend allowing at least a 2-5 minute initialization period of driving prior to GPS signal loss or degradation.