Designing NXT Robot for Position Control

Abstract

The main idea of this work to design and programming that executed given orders and tasks such as moving pin in curveting path, hand slope, catching bodies of plastic, for example if we want the robot to catch a blue ball the robot we programming him by the NXT program, after that the robot moves to the required point, then the light sensors detect weather the ball has the ordered color or not, if so the robot bring it, otherwise the robot return back to the point where he launched from. Realizing predetermined task can be achieved by uploading the program code the NXT intelligence brick then it can applied automatically In designing at first we explain about building the frame and the structure of the robot body, then we explain the usage of the gear box which they used to increase or decrease the velocity, we talk about the pulleys and their usage, their implementation, the five sensors sound sensor, touch sensor, Ultrasonic sensor, light sensor in addition to encoder embedded to the motor, each sensor has specified own function to do, each sensor situated in the position required to do the task in proper way, the NXT brick situated in the center of the robot to convenient the communications between the transducers and the actuators, the two DC-Servo motors are positioned in the bottom part of the robot to attach the motors rotor with the wheels for moving the robot while the third one “also DC-Servo” is situated in the upper part to do the task. The result from this work states that the robot implenent the task precisely according to the code downloaded to the Brick that’s why the usage of DC Servo motor, but We notice that somehow the encoder attached to the shaft has little error so that some errors occurs, in addition to that the gears has backslash problem while attaching, the size of the wheels has a relationship with the speed of the robot