A fuzzy autopilot for track-keeping control of underwater vehicles is considered. Input variables fuzzification, fuzzy rules and output set defuzzification are described. Quality of control of the fuzzy tracking controller under influence of the sea current disturbance was analysed and compared to a traditional PD controller. Some computer simulations are provided to demonstrate the effectivene...

A neural network model reference adaptive controller for trajectory tracking of nonlinear systems is developed. The proposed control algorithm uses a single layer neural network that bypasses the need for information about the system’s dynamic structure and characteristics and provides portability. Numerical simulations are performed using nonlinear dynamic models of marine vehicles. Results ar...

In this paper we present a visual navigation system for retrieving untethered autonomous underwater vehicle (AW). The vision qstern guides the .4LV into a retriever which is a tethered underwater robot. The visual navigation modules include target searchin& line tracking, and positioning. The vision system is a dedicated parallel image processor composed of three T800 (Transputer). The processi...

This paper reports the development of a new hydrodynamics test facility for UUV dynamics, navigation, and control research. Located at the Johns Hopkins University, the facility’s 174,000 liter water tank, navigation instrumentation, and testbed ROV provides the ability for development of advanced underwater vehicle systems. Experimental data demonstrating the performance of the facility’s sens...

In this paper, we consider the time minimal problem for an Autonomous Underwater Vehicle. We investigate, on a simplified model, the existence of singular extremals and discuss their optimality status. Moreover, we prove that singular extremals corresponding to the angular acceleration are of order 2. We produce in this case a semicanonical form of our Hamiltonian system and we can conclude the...

vehicles. Sliding mode control was one of the fi rst control methods implemented for underwater vehicles. It has shown advantages in several implementations. Different control methodologies used for underwater vehicles are categorized by Fossen. In the work of Logan, H/msynthesis methods are compared with the sliding mode method. A comparison of different control techniques, including artifi ci...

A powerful adaptive filter algorithm for estimation of forces acting on an Autonomous Underwater Vehicle (AUV), and the corresponding adaptive control law which determines the desired heading commands are considered in this paper. Due to the complicated nature of AUV’s task and incorporation of the ocean current, uncertain parameters arise in thc equations of motion that constitute the AUV’s dy...