Using the Inertial+’s improved configuration

Software Releases

August 30, 2011

160_ConfigurationOxTS is releasing a quick way to save the Kalman filter’s improved configuration into the Inertial+.

Why is this useful? You’ve driven and warmed up your Inertial+. The Kalman filter has learned some critical parameters about your configuration, like the mounting angle of the two GPS antennas used for heading and the mounting angle of the Inertial+ in the vehicle. It has improved the measurement of the external GPS antenna position. Wouldn’t it be good to use these values next time you turned on your Inertial+ rather than relying on the Kalman filter to estimate them again?

With the new version of i+config it is easy to transfer the improved configuration from the Inertial+ and include them in a new set of configuration files. These files can then be downloaded to the Inertial+ where they will be used each time the Inertial+ starts up in the future.

There are a few advantages to doing this, mostly to do with repeatability.

In open sky conditions, with good GNSS reception, it is relatively easy for the Inertial+ to estimate the position of the external GNSS antenna accurately. In dense urban conditions it is much more difficult. A GNSS position error early on in the warm-up can throw off the Kalman filter and it can take a while before the Kalman filter can correct this error. However, if the primary antenna position is estimated in open sky and included in the configuration that is committed to the Inertial+ then GNSS position errors will have little effect on the Kalman filter’s estimate of the external antenna’s position.

This situation is even more useful on dual-antenna systems. Sometimes it is not easy to estimate the orientation of the two GPS antennas used for heading on an Inertial+2, for example on a boat where dynamics are low. In other situations it is useful to have accurate heading earlier during the warm-up period. Programming the orientation of the antennas into the Inertial+2 helps both these problems. It makes the heading angle more repeatable, especially early on during the file.

This situation is even more useful on dual-antenna systems. Sometimes it is not easy to estimate the orientation of the two GPS antennas used for heading on an Inertial+2, for example on a boat where dynamics are low. In other situations it is useful to have accurate heading earlier during the warm-up period. Programming the orientation of the antennas into the Inertial+2 helps both these problems. It makes the heading angle more repeatable, especially early on during the file.

To find out more about this new feature please see the Inertial+ user manual or contact us.