Autonomous Underwater Vehicle Robust Path Tracking: Auto-Adjustable Gain High Order Sliding Mode Controller

Disturbance Observer-Based Double-Loop Sliding-Mode Control for Trajectory Tracking of Work-Class ROVs

The open-frame structure of work-class ROVs results in significant model uncertainties, and its motion is strongly disturbed by the umbilical cable. To address these problems, this article developed a nonlinear disturbance observer-based super-twisting double-loop sliding-mode control (NDO-STDSMC) method to achieve trajectory tracking control of work-class ROVs with system uncertainties and external disturbances. First, a new outer-loop controller with a novel reaching law is designed to increase the convergence rate compared with the existing double-loop sliding-mode control (DSMC). Second, an inner-loop controller that combines the advantages of the super-twisting sliding-mode scheme is proposed to guarantee the tracking error converges to zero in finite time. Then, a nonlinear disturbance observer is designed to estimate and compensate for the system uncertainties and external disturbances. The stability of the overall control system is proven by the Lyapunov approach. Finally, comprehensive simulation studies on trajectory tracking control of work-class ROVs are provided to demonstrate the efficiency of the proposed NDO-STDSMC method and its superiority over existing DSMC and STDSMC methods.

A MBSE Application to Controllers of Autonomous Underwater Vehicles Based on Model-Driven Architecture Concepts

In this paper, a hybrid realization model is proposed for the controllers of autonomous underwater vehicles (AUVs). This model is based on the model-based systems engineering (MBSE) methodology, in combination with the model-driven architecture (MDA), the real-time unified modeling language (UML)/systems modeling language (SysML), the extended/unscented Kalman filter (EKF/UKF) algorithms, and hybrid automata, and it can be reused for designing controllers of various AUV types. The dynamic model and control structure of AUVs were combined with the specialization of MDA concepts as follows. The computation-independent model (CIM) was specified by the use-case model combined with the EKF/UKF algorithms and hybrid automata to intensively gather the control requirements. Then, the platform-independent model (PIM) was specialized using the real-time UML/SysML to design the capsule collaboration of control and its connections. The detailed PIM was subsequently converted into the platform-specific model (PSM) using open-source platforms to promptly realize the AUV controller. On the basis of the proposed hybrid model, a planar trajectory-tracking controller, which allows a miniature torpedo-shaped AUV to autonomously track the desired planar trajectory, was implemented and evaluated, and shown to have good feasibility.