Implementation of pitch on an ROV: Retrofitting a Cougar XT

Pitch implemenetering på en ROV

Roos, Rolf Magnus

7. term

Electronic and Computer Engineering

2017

2017-01-10

Målet med projektet er at give et ROV (fjernstyret undervandsfartøj) mulighed for at udføre pitch, dvs. næsen op/ned-rotation omkring tværaksen, som systemet i dag ikke kan. Pitch-styringen udvikles som en selvstændig regulator, der arbejder uafhængigt af ROV'ens interne kontrolsystemer. For at skabe den nødvendige drejekraft til pitch anvendes en thruster (propel), og projektets hovedfokus er at designe den styring, der driver denne thruster. Arbejdet starter med en matematisk beskrivelse af både ROV'et og thrusterens dynamik. ROV-modellen bygger på en kraftbalance, der beskriver de kræfter, som påvirker pitch-vinklen. Heraf følger, at den kraft thrusterens styring skal levere for at opnå en given vinkel, skal have samme størrelse som de forstyrrende kræfter, men være rettet modsat. Hele systemet samles i Simulink (Matlab) for at kunne simulere og analysere adfærden. På baggrund af disse simulationer udvikles en PI-regulator (proportional–integral), som ved hjælp af tilbagemelding fra vinkelmålingen kan fastholde den ønskede pitch-vinkel.

The project aims to enable pitch maneuvers on a Remotely Operated Vehicle (ROV), meaning nose-up/nose-down rotation about the lateral axis, which the current system cannot perform. The pitch controller is designed as a standalone unit that operates independently of the ROV’s internal controllers. A thruster (propeller) provides the force needed for pitching, and the main focus is to create the thruster controller that makes this possible. We first derive mathematical models of the ROV and the thruster dynamics. The ROV model is based on a force balance that describes the forces acting on the pitch angle. From this, the controller must command a force equal in magnitude and opposite in direction to the disturbances to achieve a desired angle. The complete system is implemented in the Simulink toolbox in Matlab to allow simulation and analysis. Based on these simulations, we develop a PI (proportional–integral) controller that, using feedback from the measured angle, maintains the desired pitch.

[This abstract was generated with the help of AI]

Control Systems ; SubC Partner ; Feedback system ; Black box modelling ; ROV ; Matlab ; Simulink ; Pitch

Download
View record in AAU Student Projects