Small Unmanned Surface Vehicle Research Articles

Human-computer Interface Studies for Semi-autonomous Unmanned Surface Vessels

A series of four experiments were performed during an iterative design evolution of the human-computer interface (HCI) to a small unmanned surface vehicle (USV). The baseline control system was compared to several alternate designs using a simulated naval mission. User tasks included the monitoring and control of one or two vessels simultaneously. Faults and hazards were included to stimulate emergency responses during vessel transit. Alternate HCI designs varied across these factors: visual integration, synthetic audio feedback, sizing and placement of alerts, and use of a hand-held game controller as a primary input device. Results for N=32 sailors across the four studies indicated that for single or dual USV control conditions, the interface features added to the baseline design significantly improved speed and accuracy across multiple mission tasks. However, all design configurations still yielded some collision errors indicating that operator visual monitoring and manual control may be inadequate in complex, cluttered transit environments. Therefore, on-board automatic obstacle avoidance systems may be needed to safely support multiple vessel operations in cluttered complex transit environments.

A Virtual Target-Based Underway Docking Procedure for Unmanned Surface Vehicles

AbstractThis paper considers the topic of safely docking a small unmanned surface vehicle (USV) with a larger mother ship moving in transit at sea. The proposed underway docking procedure is divided into two distinct phases to ensure a controlled and collision-free operation. Specifically, a safety circle is defined around the mother ship together with a virtual target point that can move along its circumference. During the whole procedure, the mother ship passively moves forward in a straight line while the USV actively tracks the target point using constant bearing guidance. In the first docking phase, the target is positioned at the projection of the USV position onto the safety circle surrounding the mother ship. When the USV has matched its position and velocity with the projected target point, the second phase is initiated by the target point starting to move along the safety circle until its bearing matches up with that of the desired docking point. Subsequently, the target point starts reducing its distance from the safety distance until it becomes equal to that of the docking point such that docking is finally achieved. The suggested underway docking procedure represents a simple and intuitive method which is easy to implement and tune. Its performance is illustrated through a computer simulation with an underactuated USV docking with a mother ship in transit.

Development of Dual Mode (Autonomous and Remote Control) Unmanned Surface Vehicle

These days, a study on 'Unmanned Surface Vehicle (USV)' has made very active progress in many countries. Even if it is being expected that there will be a great demand of USV for wide field, such as military operation, private sector, and etc., the study of USV in Korea is still at an early stage. For this reason, we have made a very small USV which is composed of dual mode (autonomous and remote control). The TCP/IP communication is applied to the USV.

Shallow Water Surveying Using Experimental Interferometric Synthetic Aperture Sonar

AbstractThis paper describes an interferometric synthetic aperture sonar system based on an unmanned surface vehicle customized for shallow water environments. Synthetic aperture sonar enables imagery of high resolution that is independent of range by using the displacement of the sonar platform to create a large virtual array. If two geometrically displaced images are obtained, the construction of three-dimensional topographic maps is possible through the use of interferometric techniques. The use of an unmanned surface vehicle presents several advantages that alleviate some problems related to the formation of synthetic aperture images, which are mainly related to the fact that a precise navigation system can be used for the boat control and sonar imagery motion compensation. Also, a small unmanned surface vehicle is advantageous in terms of cost of operation, maintenance and ease of deployment. Mapping of shallow water areas is an important task for many commercial and scientific applications like river navigability, infrastructure maintenance and natural resource monitoring. These tasks can be done efficiently with this system. Sample data obtained during test trials illustrate how synthetic aperture can be used to generate underwater imagery and bathymetric data.