Development of an intelligent underwater robotic manipulator system

Abstract

We focus on the technology development and implementation of an intelligent underwater robotic manipulator system. The objective is to establish an underwater manipulator system that has the capability of remotely teleoperated, window-guided supervisory control, high-level task planning, and image sensing. The system includes four main modules according to their functionality. They are: task planning module, image process and identification module, distance measurement module, and motion control module. The key components developed include a five-jointed underwater manipulator, an ultrasonic distance measuring system, an image process and identification software, and a Petri-Net based task-planning software. The manipulator was designed and fabricated to be an articulate type robot with five rotary joints. For the task-planning process, we applied colored Petri-net technology to define the model of the underwater tasks. For the image identification process, we established an image process module that is responsible for providing clear underwater image, performing pattern recognition tasks, and generating imagery information demanded by the task-planning module. For the motion control and trajectory planning process, polynomial interpolation was used for the trajectory planning, and real-time inverse kinematics was performed to obtain the actuators' input angles. By integrating the above technologies, the finished prototype of the manipulator system shows its ability to achieve our research goals.