•
The result is a dramatic
reduction of the effective drift, which results in up to two orders of
magnitude lower heading errors! •
HDR requires no hardware at all.
It is a small software segment that can be added to any existing program
code.
•
HDR works with any gyro or
IMU; it is most effective with low-cost/high-drift gyros.
Plot on the right: Experimental results from a
highway drive with a Memsense nano-IMU in a small SUV. Total distance: 50
miles, total travel time: 48 minutes. The drift rate of the gyros in
the nIMU is >80 deg/hour. Within a few minutes the gyro data becomes useless
(see red curve). The average heading error of the uncorrected gyro was 153
deg. In contrast, with HDR correction (see green curve) the average error
was only 5 deg. This is a 33-fold improvement!
Notes:
1. Ground truth was provided by GPS (cyan curve).
2. HDR parameters were tuned for best performance in this experiment.
3. With untuned parameters, HDR improvements range from 3-fold to 100-fold,
depending on the drift rate of the gyro.
4. Odometry data, needed for plotting position, was derived from GPS data
since we had no access to the odometer in the test car.
