The motivation of this research is to obtain an accurate three-dimensional (3D) layout of an underground conduit, which may be beneficial to optic fiber cable installers and engineers. A newly designed algorithm for 3D position tracking with the help of an inertial sensor and an encoder has been developed. Two types of representations (Euler angle and Quaternion) for orientation and rotation are also introduced, followed by several data pre-processing procedures. A sensing fusion method is utilized to overcome the accumulated errors introduced by the sensor drifting. Considering the application of 3D underground duct mapping in this research, a sensing system using the newly designed algorithm was designed and analyzed. Additional information, such as the orientation and position of the starting and ending points, are integrated into the algorithm to correct the sensing drifting and refine the position estimation. To verify and demonstrate the design of the algorithm and sensing system for 3D underground duct mapping, an experimental test-bed based on the sensing system design, which consists of an IMU, a duct rodder and a fiber blower, was developed. Experiments on three different layouts of the conduit were conducted and analyzed to demonstrate the feasibility and efficiency of the newly developed algorithm and the sensing system design.


Min Li

Committee Member

Patrick Tebbe

Committee Member

Qun Zhang

Date of Degree




Document Type



Master of Science (MS)


Mechanical and Civil Engineering


Science, Engineering and Technology



Rights Statement

In Copyright