Thrust control of electric marine thrusters

Abstract

This paper deals with the problem of the control of thrust generated by conventional bladed propeller of marine thrusters and moved by an electric motor. This paper described a control law based on the estimation of the thrust using two features: an Extended Kalman Filter to observe the torque and an reversed hydrodynamic model of the propeller to control the thrust by a Proportional-Integral controller. The performances and robustness of this control law is compared to a PI controller without estimator and to the Model-Based-Velocity control.

Nonlinear Thrust Controller for Marine Propellers in Four-Quadrant Operations

“…In the last years also the effect of the thruster and propeller dynamics and control has been studied [6], [12], [2], [7] and [1].…”

A Four-Quadrant Thrust Estimation Scheme Based on Chebyshev Fit and Experiment of Ship Model

“…*Address correspondence to this author at School of Computer Science and Engineering, South China University of Technology, Guangzhou, China; Tel:+86 13143737141;Email:jiafu_wan@ieee.org Its estimation was based on the measurement of the propeller torque and a linear relation between thrust and torque. The topic of thrust estimation has also been investigated in [17], the propeller thrust values were provided by the propeller torque obtained with a Kalman filter where a linear shaft friction torque was considered. The relation between thrust and torque involved an axial flow velocity model and a requirement of the knowledge of the advance speed, both of which are very difficult to measure.…”

Experimental Validation of a Marine Propeller Thrust Estimation Scheme

“…There are also losses of thrust due to the interaction between the vessel hull and the propeller. * Published at the 7th Conference on Manoeuvring and Control of Marine Craft (MCMC2006), Lisbon, Portugal, September 20-22, 2006. Recently, observers for monitoring the propeller performance have been developed and included in new control designs for electrically driven propellers, see Guibert et al (2005) and Smogeli (2006). All these considerations motivate the development of schemes to estimate the propeller thrust because, in general, its measurement is not available.…”

“…The mapping to compute the thrust from the propeller torque has been improved in order to increase the accuracy when the propeller is lightly loaded. Differently from Guibert et al (2005) the advance speed is assumed to be unknown. The scheme has been tested in waves to reproduce rough sea conditions and with a device that simulates the influence of a vessel hull.…”

“…Thrust estimation has been also treated in Guibert et al (2005), where the estimate was computed from the propeller torque obtained with a Kalman filter where a linear shaft friction torque was considered. The relation between thrust and torque involved an axial flow velocity model and required the knowledge of the advance speed, very difficult to measure in real vessel.…”