Improved Inertial/Odometry/GPS Positioning of Wheeled Robots Even in GPS-Denied Environments - Global Navigation Satellite Systems: Signal,Theory and Applications - page 269

Fig. 2. The mobile robot used for the experiments in this work, custom-built by the author
and members of the Electrical and Computer Engineering Department at Royal Military
College of Canada.
3.2 Equipment
The inertial sensors used in this work include a MEMS-grade IMU made by Crossbow, model
IMU300CC-100. Specifications of this IMU are in table 1 and detailed specifications can be
found in ( IMU300CC - 6DOF Inertial Measurement Unit , 2009). Velocity updates are provided
by the forward speed of the robot, derived from encoders coupled to the drive output of
each motor. The results of the presented navigation solution are evaluated with respect to a
reference solution made by NovAtel where a Honeywell HG1700 high-end tactical grade IMU
is integrated with a NovAtel OEM4 GPS receiver. The IMU and GPS receiver are integrated
with a G2 Pro-Pack SPAN unit which is an off-the-shelf system developed by NovAtel. The
details of this system are described in ( SPAN Technology System User Manual OM-20000062 ,
2005). Biases and scale factors for the HG1700 IMU are in table 2 and detailed specification
can be found in ( HG1700 Inertial Measurement Unit , 2009). The high-cost NovAtel SPAN
system provides a reference solution to validate the proposed method which uses the low-cost
MEMS-based sensors. The SPAN system is also used to examine the overall performance
during some GPS outages intentionally introduced in post-processing. A basic block diagram
of the sensor electronics on-board the mobile robot appears in fig 3.
4. Results and discussion
Trajectories are carried out using the mobile robot described in Section 3 and sensor data
is collected to test the developed solution in post-processing. Four navigation solutions are
compared in order to show the benefit of using RISS instead of a full IMU and the benefit of