abstract
- © 2019 Elsevier B.V.This paper addresses the modeling of an autonomous underwater vehicle using quaternion formulation for angular position description and Lagrange method to compute the equations of motion. As the four parameters are dependent and generate a constraint, Lagrange multipliers are used with Baumgarte method to solve and stabilize the system. The dynamic model includes underwater effects like added mass and inertia, hydrodynamic damping, buoyancy and propeller forces. Moreover, a quaternion-based line of sight guidance algorithm is derived to avoid any use of trigonometric function and compute directly the orientation error of the underwater vehicle and the desired attitude in terms of quaternions. Motion control is achieved with a quaternion-based adaptive sliding mode controller rejecting model uncertainties and water current. The simulation results, where the vehicle follows a sequence of way-points including vertical diving motion demonstrate that the proposed guidance algorithm and motion control are deeply relevant both in terms of effectiveness and robustness for this particular type of vehicle and orientation formulation.