The paper presents a simple method of tuning a PD controller for controlling the depth of an autonomous underwater vehicle. The non-linear dynamics of the depth of the vehicle are linearised and approximated as an integrating process with deadtime. The PD controller tuning is then done using gain margin specifications. Keywords—Autonomous Underwater Vehicle, Dead-time, integrating process, PD c...

In recent years underwater robotics has become a major area of research owing to the development of many diverse technologies. Autonomous underwater vehicles (AUVs) are used today for exploration, pipeline monitoring, military reconnaissance and other scientific tasks. AUVs can also be used effectively to teach principles in many disciplines of science ranging from physics to robotics. Any good...

This paper describes the design and implementation of a mission control system for the MARl US autonomous underwater vehicle (A U V). The framework adopted for system design builds on the key concept of vehicle primitive, which is a parametrized specification of an elementary operation performed by the vehicle. Vehicle primitives are obtained by coordinating the execution of a number of concurr...

This paper presents a novel Nonlinear Model Predictive Control (NMPC) scheme for underwater robotic vehicles operating in a constrained workspace including static obstacles. The purpose of the controller is to guide the vehicle towards specific way points with guaranteed input and state constraints (i.e obstacle avoidance, workspace boundaries). The proposed scheme incorporates the full dynamic...

The control of autonomous underwater robotic vehicles includes many challenges. The highly nonlinear, timevarying dynamic behavior of the robot continually changes the parameters of the system model. The uncertainties in hydrodynamic coefficient make system identification difficult. Disturbances acting on the robot, such as ocean currents, continually affect the system. This paper presents a no...

Reinforcement learning uses a scalar reward signal and much interaction with the environment to form a policy of correct behavior. We have applied this technique to the problem of developing a controller for an autonomous underwater vehicle and have achieved reliable off-line development of stable controllers. Many important underwater tasks rely upon on visual observation of underwater feature...

This paper presents a digital resolved acceleration control method for coordinated motion control of an underwater vehicle equipped with manipulators. Using this method, in spite of large position and attitude errors of the underwater vehicle, good control performances of the end-tips of the manipulators to follow a pre-planned trajectory can be achieved. In this work, theoretical work of the p...

This paper proposes an adaptive robust control scheme for an Underwater-Vehicle Manipulator System (UVMS). The proposed controller enables the tracking of the intersection of multiple local sub-regions that are assigned for each subsystem of a UVMS under the influence of modelling uncertainties as well as additive disturbances. The presence of variable ocean currents creates hydrodynamic forces...

We present an application of HUGIN to solve problems related to diagnosis and control of autonomous vehicles. The application is based on a distributed architecture supporting diagnosis and control of autonomous units. The purpose of the architecture is to assist the operator or piloting system in managing fault detection, risk assessment, and recovery plans under uncertainty. To handle uncerta...