5.2. Experiment procedures

In the simulation experiment, Husky A200™ robot moves in a near rectangle corridor, which is around 70 m in length and 40 m in width. The detailed control parameters of Husky A200™ robot are set as following:


In addition, the whole experiment is conducted within indoor and seven landmarks are derived from the coordinates measured by DGPS from roof corners of the experimental building to be set as referenced landmarks.

Figure 9 displays seven red landmarks at some corners of the rectangular corridor, which are derived by the seven yellow circle coordinates at the roof corners of the experimental building. Moreover, the starting point or final point of the experiment is shown on the upper right position of the floor map by a star symbol.

Micro-Inertial-Aided High-Precision Positioning Method for Small-Diameter PIG Navigation 65 http://dx.doi.org/10.5772/intechopen.80343

Figure 9. The landmarks for the experiment in corridor.

#### 5.3. Experimental results and analysis

#### 5.3.1. Pipeline junction detection

In Figure 10, the PJ detection result is obtained by Z-axis accelerometer measurement data of VTI IMU with FOS. The blue and red signals denote the raw and denoised accelerometer measurement data, respectively. The difference between the blue and red signals not only revealed the feasibility of FOS denoising on VTI IMU, but also demonstrated that the

Figure 10. The PJ detection results by FOS.

signal-to-noise ratio of accelerometer measurement data could be improved greatly. In addition, the yellow curve in Figure 10 is the PJ detection results; the spike intervals display that the Husky A200™ robot is passing a 90˜ corridor or a preset protrusion, while the rest of the intervals represents the robot going through the straight corridor segment.
