This paper proposes a kinematic model and an inertial localization system architecturefor a riser inspecting robot. The robot scrolls outside the catenary riser, used for underwaterpetroleum exploration, and is designed to perform several nondestructive tests. Itcan also be used to reconstruct the riser profile. Here, a realistic simulation model of robotkinematics and its environment is proposed, using different sources of data: oil platformcharacteristics, riser static configuration, sea currents and waves, vortex-induced vibrations,and instrumentation model. A dynamic finite element model of the riser generatesa nominal riser profile. When the robot kinematic model virtually scrolls the simulatedriser profile, a robot kinematic pattern is calculated. This pattern feeds error models of astrapdown inertial measurement unit (IMU) and of a depth sensor. A Kalman filter fusesthe simulated accelerometers data with simulated external measurements. Along the riservertical part, the estimated localization error between the simulated nominal and Kalmanfilter reconstructed robot paths was about 2 m. When the robot model approaches theseabed it assumes a more horizontal trajectory and the localization error increases significantly.
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