ระบบควบคุมและระบุตำแหน่งของหุ่นยนต์สำรวจใต้น้ำแบบสี่องศาอิสระ

Abstract

Nowadays remotely operated underwater vehicles (ROUV) become necessary equipment for many underwater tasks. However, there are many underwater dynamic- motion characteristics of ROUV, e.g., motion drifting, dynamics of the ROUV thruster, balancing between ROUV weight and buoyancy force, uncertain force from cable wire and underwater field-of-view limitation, that cause difficulty for an operator to control an ROUV even without the water current. In this research, PID stabilization control system is applied to the ROUV and localization system is developed based on Hector SLAM which is a software package of Robot Operating System (ROS). The Pl stabilization controller relies on the horizontal velocity, depth and yaw-angular velocity feedbacks to control the robot motion in the corresponding directions. The ROUV hardware consists of a computer laptop, an Arduino board and a Raspberry Pi board as processor unit, thrusters, motor drive boards, a pressure sensor for depth measurement, a gyroscope and magnetometer of IMU for orientation measurement, Lidar sensor for measuring horizontal distance and determining robot position by using Scan Matching algorithm. The experiments are performed on the developed underwater robot. The ROUV, consisted of 6 thrusters, has an automatic feedback-control system for 4 degrees of freedom motion, which is a main contribution of this research. The research results show that the localization system of the ROUV is able to precisely maintain real-time position and yaw orientation. The controlled system is able to maintain the ROUV at the 3D stationary target position and to maneuver along the desired path.