ISSN:
1573-7527
Keywords:
subsea robot
;
subsea robot modeling
;
robust control for subsea robot
;
nonlinear control
;
autonomous
;
underwater task
Source:
Springer Online Journal Archives 1860-2000
Topics:
Computer Science
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract This paper presents a new approach for designing simple nonlinear robust controllers for underwater vehicles. The paper presents several in-water experiments performed on the VORTEX vehicle developed by IFREMER. We first introduce some general modeling considerations of underwater vehicles, then we present the VORTEX dynamic model and some of the special features of the VORTEX vehicle that are important for control. Among these, low sampling rates for sensor and actuator nonlinearities are considered. The main aim of this paper is to experimentally investigate the benefits of adding an easy-to-tune nonlinear control loop to the actual linear compensator in order to improve the stability and the disturbance rejection properties of the closed-loop system. The advantage of this method is two-fold. First the additional nonlinear loop does not modify the original linear (PID) regulator. Second the design of this additional loop does not rely on the system model and is simple to tune. The results presented in this paper were obtained using the VORTEX vehicle both in simulation and during real experiments; they demonstrate the advantages of using a PID with this nonlinear loop over a simple PID control.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00141155
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