This paper proposes a kinematic model and an inertial localization system architecture for a riser inspecting robot. The robot\r\nscrolls outside the catenary riser, used for underwater petroleum exploration, and is designed to perform several nondestructive\r\ntests. It can also be used to reconstruct the riser profile. Here, a realistic simulation model of robot kinematics and its environment\r\nis proposed, using different sources of data: oil platform characteristics, riser static configuration, sea currents and waves, vortexinduced\r\nvibrations, and instrumentation model. A dynamic finite element model of the riser generates a nominal riser profile.\r\nWhen the robot kinematic model virtually scrolls the simulated riser profile, a robot kinematic pattern is calculated. This pattern\r\nfeeds error models of a strapdown inertial measurement unit (IMU) and of a depth sensor. A Kalman filter fuses the simulated\r\naccelerometers data with simulated external measurements. Along the riser vertical part, the estimated localization error between\r\nthe simulated nominal and Kalman filter reconstructed robot paths was about 2m. When the robot model approaches the seabed\r\nit assumes a more horizontal trajectory and the localization error increases significantly.
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