5796 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 65, NO. 7, JULY 2018
Trajectory Tracking Control of an Autonomous
Underwater Vehicle Using Lyapunov-Based
Model Predictive Control
Chao Shen , Member, IEEE, Yang Shi , Fellow, IEEE, and Brad Buckham, Member, IEEE
Abstract—This paper studies the trajectory tracking con-
trol problem of an autonomous underwater vehicle (AUV).
We develop a novel Lyapunov-based model predictive con-
trol (LMPC) framework for the AUV to utilize computa-
tional resource (online optimization) to improve the trajec-
tory tracking performance. Within the LMPC framework, the
practical constraints, such as actuator saturation, can be
explicitly considered. Also, the thrust allocation subprob-
lem can be addressed simultaneously with the LMPC con-
troller design. Taking advantage of a nonlinear backstep-
ping tracking control law, we construct the contraction con-
straint in the formulated LMPC problem so that the closed-
loop stability is theoretically guaranteed. Sufficient condi-
tions that ensure the recursive feasibility, and hence the
closed-loop stability, are provided analytically. A guaran-
teed region of attraction is explicitly characterized. In the
meantime, the robustness of the tracking control can be
improved by the receding horizon implementation that is
adopted in the LMPC control algorithm. Simulation results
on the Saab SeaEye Falcon model AUV demonstrate the sig-
nificantly enhance trajectory tracking control performance
via the proposed LMPC method.
Index Terms—Autonomous underwater vehicle (AUV),
backstepping, Lyapunov-based nonlinear control, model
predictive control (MPC), thrust allocation (TA), trajectory
tracking.
I. INTRODUCTION
T
HE autonomous underwater vehicles (AUVs) exemplify
the recent advances in the marine robotics field and
has been receiving a growing interest from both industry and
academia due to their potential to substantially reduce risks and
operational costs in various submarine projects [1]. The core
feature of the AUV refers to the capability of reacting appro-
priately during the missions without intervention from human
Manuscript received June 19, 2017; revised September 6, 2017, and
October 24, 2017; accepted November 5, 2017. Date of publication De-
cember 4, 2017; date of current version March 6, 2018. This work was
supported in par t by the Natural Sciences and Engineering Research
Council of Canada, and in part by the National Natural Science Foun-
dation of China under Grant 61473116. (Corresponding author: Yang
Shi)
The authors are with the Department of Mechanical Engineering
and the Institute for Integrated Energy Systems (IESVic), University of
Victoria, Victoria, BC V8W 3P6, Canada (e-mail: shenchao@uvic.ca;
yshi@uvic.ca; bbuckham@uvic.ca).
Color versions of one or more of the figures in this paper are available
online at http://ieeexplore.ieee.org.
Digital Object Identifier 10.1109/TIE.2017.2779442
operators, which, on the other hand, justifies an elaborated con-
trol system [2]–[4].
The trajectory tracking is one fundamental functionality of
the AUV control system, but is never an easy task. The highly
nonlinear and cross-coupled system dynamics together with the
unpredictable complex underwater environment, which intro-
duces considerable disturbances and uncertainties challenges
the controller design. There exist plenty of research studies in
the literature devoted to the AUV trajectory tracking control.
When the desired trajectory is piecewise linear (i.e., way-point
tracking), the assumptions for l ocal linearization can hold, and
the classic linear control techniques are applied to solve the tra-
jectory tracking problem [5]. The linear control methods, such as
the proportional-integral-derivative (PID) and linear-quadratic-
regulator are often preferred due to their easy implementation.
However, linear control techniques will be no longer effective
if the desired trajectory represents a curve in the workspace,
because the curve trajectory, by nature, emphasizes the non-
linearity of the AUV motion. Therefore, the nonlinear control
techniques are often resorted to for the tracking controller de-
sign. The Lyapunov-based backstepping control (BSC) repre-
sents the mainstream method for the AUV tracking control be-
cause the control law exploits those “good” nonlinearities in the
system dynamics, which gains additional robustness compared
to the inverse dynamics control (feedback linearization). Ex-
amples include [6] and [7]. In [6], the AUV trajectory tracking
control considers the complete kinematics and dynamics of the
motion and design the control law using the backstepping tech-
nique. An output feedback tracking control via Lyapunov-based
backstepping can be found in [7]. Due to the insensitivity to
model uncertainties, the sliding model control (SMC) becomes
the other mainstream nonlinear method for the AUV trajectory
tracking control. In [8], an enhanced trajectory tracking perfor-
mance is obtained by the combining the SMC, PID, and robust
control. To eliminate the main drawback associated with the
SMC, known as the “chattering” effect, in [9], an adaptive law
is incorporated in the control law design. In [10], the higher
order sliding mode is used for the chattering-free trajectory
tracking control. Most recent studies on autonomous vehicle
tracking control try to address more practical issues [11]–[13].
The system constraints, such as thrust limit and safe operat-
ing area are inevitable in real AUV applications, hence, it is
desired to consider these constraints in the tracking controller
design.
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