University
of Bridgeport
University
of Bridgeport
ROBI - The Web Operated Arm
This project tries to combine two of the most fascinating fields in the present technology, The field of Robotics, and the world embracing INTERNET. The final goal is to have a robotic arm which is fully controllable from a WWW page, launched anywhere in the world.
The heart of the project is the Electrically Operated Manipulator Arm, located at the RISC laboratory in the University of Bridgeport's CSE department (the above picture). The manipulator arm is a model SIR-1 and has 5 degrees of freedom. It is an articulated manipulator with a RRRRR configuration (if the last few sentences sounded totaly obscure maybe you should visit our lab's introduction to Robotics for a comprehensive introduction to the field). Currently, only 3 degrees are being used to move the robot.
The Robot itself is controlled by a computerized controller. The controller accepts commands to move each joint, operates the motors, and using a variety of sensors on the arm, controls the motors until the desired point has been reached.
The controller gets the commands from a PC through a serial link. The PC is responsible for the dispatch of the correct command (according to the user's request) and for the correct translation (see Inverse Kinematics - in the above introduction) and limit control. It also serves as the last part of the INTERNET side chain.
When you are gaining control over our robot your Web Browser starts a conversation with the University's HTTP server (a SUN SPARCserver 1000). When your request to move the robot is submitted, the HTTP server receives it and does preliminary processing on it. It then sends it over the CSE department's Ethernet network to the controlling PC in the RISC lab using a STREAM-SOCKET (the PC SOCKET is implemented using Univ. of Waterloo's WATTCP package).
The PC (a Pentium 100Mhz machine) is acting as the robot's server. It receives the request, processes it and sends it to the controller. It then waits for the robot to complete it's movement. When the robot has stopped, the PC is initiating a frame grabber attached to a TV camera which grabs a picture of the new position of the arm. The picture is then sent over the internal network back to the HTTP server for further processing.
The HTTP server receives the picture from the SOCKET (using a special Common-Gateway-Interface program), and constructs a Web page out of it. The Web page is then sent back to the user to be observed.
Currently the arm is being moved using a single relative 3D interface. The interface is using relative movements from the current position of the arm in the 3D plane. The robot is yet not calibrated and is using an arbitrary unit of distance. The movement limits of the arm is aprox. +/- 500 units in each direction.
The robot's control panel is comprised from the entry table and the action buttons. The entry table is where you give the robot the number of relative movement units you wish it to move.
The action buttons will actually initiate the movement. The HOME button will cause the arm to move to its fixed home position. You should always start a session with a home command so you'll be able to know exactly where the arm is now. The MOVE button moves the arm according to the values entered in the above table.
This project was conceived and is guided and supervised by the head of our Robotics Group Prof. Tarek Sobh. The project itself is being done by Matanya Elchanani.
You are visitor in
ROBI's home page