Steering performance test of underwater mining robot

A pilot-scale mining robot for manganese nodule has been developed by KRISO (Korea Research Institute of Ships and Ocean Engineering) in 2012. The robot consists of two unit-modules having an identical mechanical and hydraulic configuration. Each unit module has two tracks, two pick-up devices with attitude control devices, two crushers, one discharging pump, and hydraulic system. In 2013, Sea-trial has been performed at 130m depth in the east sea of South Korea. To strictly keep and follow the pre-defined complex path with a constant forward speed, steering characteristics of the mining robot are required. To know the characteristics of the robot, steering performance test was executed with appointed steering ratios. Also, for the reliable driving of the robot, the velocity pattern of four-columns tracks is determined by numerical simulation. To actuate track motor as a commanded velocity, PI controller is designed from system identification method and gain tuning rule.