The study of remotely teleoperated robotic manipulator system for underwater construction

Abstract

Most commercial underwater manipulators to date belong to master-slave type. The disadvantage of the system is that it requires the operator be well trained and fully skilled. Hence a robot manipulator system with high intelligence should be developed to fulfill the need of less-skilled or even non-skilled operators. In response to the above needs, we have designed and implemented an intelligent underwater robotic manipulator system to enhance the capability of the robotic manipulator. This developing system consists of a manipulator, a distance measurement system, water-proof camera, computer, interface technology and task planning technology etc. The system is constructed as a windows-guided, supervisory underwater robotic manipulator system. The underwater manipulator was designed and fabricated to be an articulate type robot with five rotary joints, including waist, shoulder, elbow, wrist-pitch, and wrist-roll motion. The system consists four subsystems to facilitate the intelligence behavior of the robotic system. The modules include a task planning module, an image process and identification module a distance measurement module, and a motion planning and control module. A prototype of teleoperated underwater robotic manipulator systems has been setup. The finished prototype underwater manipulator system have been used as a test station for underwater operation, to crip and more a object. The set up system is hanged under a manipulator is installed on the 6 degrees of freedom rotation platforms to simulate ROV motion under sea. The remotely teleoperated robot manipulator system hanged under the 6 degrees of freedom rotation platform can finish a underwater construction. To demonstrate the ability of the underwater robotic manipulator system, we designed an experiment for the underwater manipulator under the 6 degrees of freedom rotation platforms to simulating ROV under sea to accomplish an object crip under water with robotic system. The task planning module incorporated with the commands from the control panel, forms the highest control level of the system. In the manipulator system, the image module functions as a pre-process. It deals with tasks such as extracting target objects from CCD-images, and more importantly, providing information needed by the planning module. In distance measurement module, we have test ultrasonic and laser distance measurement system to offer main system accuracy distance information. In the motion planning and control module, the coordinates of the target position are obtained from the task planning module, then the inverse kinematics of the manipulator is performed to derive the joint angle for each joint.