Design and optimization of a 2-link type overboarding mechanism for the drop/lift automation of an active/passive sonar system in a surface ship

Active/passive type sonar systems have the receiving array that measures sound waves, transmitter towed body that converts sound waves, transmitter towing cable that controls the depth of the transmitter towed body, and array cable that connects the receiving array and transmitter towed body. With the research on the active/passive sonar system, a variety of mechanisms of the overboarding unit suitable for the limited environments have been developed. The link mechanism for efficient drop/lift of sonar system was researched in the paper of Park et al. [2] However, single link and actuator were used here that structural stability is lacked. Also, efficiency of storage also falls because complete storage inside the hull is impossible. In this paper, a sub-actuator is added in the bottom part to strength the stability of drop/lift of sonar equipment in which a link mechanism is designed to enable complete storage in the hull through the optimization of GA (Genetic Algorithm) method using MATLAB®. The mechanism proposed in this paper is 2-link type with 2 actuators equipped and is classified into the main link part and sub-link part for kinematic analysis and optimization. Reduction of required space and stability is secured compared to the Park et al.'s mechanism. This will have great advantage in the aspect of work efficiency and safety of workers, and maintenance.