M.S. (Master of Science)
Department of Mechanical Engineering
Automation and robotics are the growing phenomena replacing human labor in the industries. This idea of robots replacing humans is positively influencing the business thereby increasing its scope of research. This thesis discusses the development of an experimental platform to control a robotic arm through ROS (Robot Operating System) -- open-source framework for robot software development providing advanced capabilities for several types of robots. In ROS, the major functioning is divided into several 'nodes' that may receive or send messages to various platforms of sensors, states, and actuators. Furthermore, since ROS already has many written development packages, it allows not to deal with an opaque vendor API (Application Programming Interface) or write new device drivers in robot programming. The robotic experimental platform developed in this thesis consists of a 7-DOF manipulator arm (Robai Cyton Gamma 300) equipped with a gripper, a vision tracking system with a low-cost web camera (PlayStation Eye), and a plate held by a gripper on which a ball is balanced. The robot arm is configured to create the plate motion in two perpendicular axes by only using two joint actuators and this motion is further modeled into two decoupled, linearized systems using approximation linearization around the equilibrium point, the center of the plate. For demonstration purpose, a simple PD (proportional-derivative) control is used with the positions of the plate tracked by the actuator encoders and of the ball by the vision system. To implement the controller, a joint velocity controller for the actuators (Robotis Dynamixel servo motors) is created in ROS and OpenCV vision libraries are used to write a control program code in C++. In this thesis, taking advantage of the inter-platform operability of ROS, a system interface for a robot control is developed in which tracking an object, operating various actuators, and having a low-level control is possible with ease of programming. The system could perform some form of balancing act, but it needs further improvement. As future work, this system could be integrated with a mobile base to form a mobile manipulator for wider applications.
Khan, Khasim Ali, "ROS-based control of a manipulator arm for balancing a ball on a plate" (2017). Graduate Research Theses & Dissertations. 4786.
Northern Illinois University
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