Model identification and controller parameter optimization for an autopilot design for autonomous underwater vehicles

Abstract

Abstract-Nowadays an accurate modeling of the system to be controlled is essential for reliable autopilot. This paper presents a non-linear model of the autonomous underwater vehicle "CWolf". Matrices and the corresponding coefficients generate a parameterized representation for added mass, Coriolis and centripetal forces, damping, gravity and buoyancy, using the equations of motion, for all six degrees of freedom. The determination of actuator behaviour by surge tests allows the conversion of propeller revolutions to the respective forces and moments. Based on geometric approximations, the coefficients of the model can be specified by optimization algorithms in "open loop" sea trials. The realistic model is the basis for the subsequent design of the autopilot. The reference variables used in the four decoupled adaptive PID controllers for surge, heading, pitch and heave are provided a "Line of Sight" -guidance system. A constraint criteria optimization determines the required controller parameters. The verification by "closed loop" sea trials ensures the results.

Modular AUV System with Integrated Real-Time Water Quality Analysis

“…This paper includes a summary of the main results of the research project SALMON and has been previously published partly in [ 11 , 12 , 13 ]. The objectives of the project were: (i) to develop a miniaturized sensor system for real-time water quality analysis (ii) to assess the prospects for the implementation of such a sensor system in an AUV, and (iii) to examine the possibilities of using an AUV for water quality monitoring around fish farms.…”

Parameter Identification and Optimization of an Oceanographic Monitoring Remotely Operated Vehicle

“…Another important part of modeling is to determine the thrust allocation and the behavior of the vehicle with respect to the propellers (relation between the force/moment and the control input signal). This approach was done by Taubert and Eichhorn [8] for an AUV. The thrust characteristic identification in this paper is carried out in each degree of freedom by means of several experimental tests and the later interpolation of the obtained values through direct regression.…”