Guidance and control of an overactuated autonomous surface platform for diver tracking

The high-risk nature of SCUBA diving activities is usually dealt with by pairing up divers and adopting well defined rules for diving operations to reduce the chance of accidents. However, during more challenging dives (such as technical dives) these procedures may not be sufficient to ensure almost accident-free operations, for the divers must manoeuvre in complex 3D environments, carry cumbersome equipment, and focus attention on operational details. Technological advancement and research related to diver safety, navigation and monitoring has been identified as crucial for advancing diving activities. This paper reports current state of research performed at UNIZG-FER related to an autonomous overactuated surface platform used for following divers and transmitting GPS signal to the underwater. The implemented guidance and control algorithms are described and simulations obtained on realistic models developed in the ROS environment are provided. Special attention is given to algorithms for diver tracking by using measurements from a USBL. Diver motion estimators are used to improve the performance of the sparse and noisy USBL measurements. The results presented in this paper are a starting point for in-the-field experiments expected to take place in the real-world environment.