Coefficient diagram method for the control of an unmanned underwater vehicle

The operational demand for unmanned underwater vehicles has been growing rapidly in the recent past. For long range operations, such as oceanographic exploration and surveying, autonomous underwater vehicles (AUVs) which are equipped with on-board power and advanced control and navigation, have more promises to carry out tasks with the minimum operator intervention. Unlike other fixed platforms, autonomous underwater vehicles are particularly of interest due to their ability to provide continuous spatial and temporal observations. The safe operation of AUV relies on its autonomous navigation and control system. The paper is concerned with the synthesis of control system for an autonomous underwater vehicle using a coefficient diagram method. CDM is an algebraic approach applied to polynomial loop in the parameter space, where the so-called coefficient diagram is used as the means to convey the necessary design information and as the criteria of good design. The effectiveness of the control technique is demonstrated through a number of automatic control designs for motions in the longitudinal mode of AUV Squid, an autonomous underwater robotic designed and developed at Institut Teknologi Bandung.