Design of maritime localization system for safe evacuation of cruise ships

This work presents the design of two localization systems with the aim of providing an integrated system for safe evacuation for maritime industry and cruise ships. In this work, a low power overboard localization system is developed that aims at providing a system for localizing passengers in case they go overboard the ship. This system is based on measuring the received signal strength (RSS) between smart lifejacket tags and one interrogator station mounted inside an unmanned aerial vehicle (UAV). A new weighted least-mean-squares (WLMS) algorithm is developed for RSS based localization. Both simulation and measurement results are presented. It is shown that up to 50% improvement in positioning accuracy can be achieved using the proposed WLMS algorithm compared to the conventional unweighted least-mean-squares (LMS) solution. Simulations that study the effect of the UAV search path on the localization accuracy are presented. Measurements are carried out in a search area of 500 m × 350 m, where tags are localized with a root mean square (RMS) error of 38.4 m. The measurement results show better localization accuracy compared to other RSS based localization algorithms. In addition, large-scale sea demonstration was performed that showed the system in an operational environment. For the on-board passengers’ localization system, a novel integrated sub-harmonic frequency modulated continuous wave (FMCW) radar system based is presented, where a 24 GHz frequency divider-by-10 is used as an active reflector tag. A practical prototype is designed and fabricated on a GlobalFoundries (GF) 45 nm silicon-on-insulator (SOI) technology for the 24 GHz building blocks, while a GF 0.18 μm 7WL BiCMOS technology was used for the 2.4 GHz phase-locked-loop (PLL) and receiver (RX). Measurement results show that as opposed to conventional primary FMCW radars, the proposed system is immune to strong multi-path interferences resulting from the direct reflections of the interrogating signal. When measured in lab environment, the system achieves a ranging standard deviation of 3.7 mm. Moreover, when measured in an indoor environment, ranging results yield a ranging RMS error of 22.3 cm with a standard deviation of 5.8 cm. In addition, indoor positioning measurements are performed using an LMS algorithm. Measurement results show that the sub-harmonic FMCW radar system has a positioning RMS error of 26.8 cm with a standard deviation of 2.97 cm, which outperforms other state-of-the-art FMCW indoor localization systems. It also further proves the system ability to mitigate multi-path interferences in complex indoor environments.