Data Acquisition for Angular Measuring and Positioning System

This paper presents an angular positioning system to rotate a web camera. These systems are used in security systems for supervision. The controller for the positioning system is developed around a microcontroller PIC 18F4455 type. To follow the response of the controller a virtual instrument was developed in LabWindows/CVI. From the front panel can be set two function modes the manual or the automatic. In manual mode the user sets the reference angle for the positioning system. In automatic mode the system detects movements with sensors and rotates a web camera in the direction of the movement. Two different position sensor types for position measurement will be presented, a resistive an incremental type. It will be studied the sensor's accuracy and measurement accuracy. It is presented different control methods which can be used in a positioning system. Further it is developed a classical PI controller and the parameters are established experimentally. A model identification adaptive controller was also developed. Adaptive control is the attempt to redesign the controller while online, by looking at its performance and changing its dynamic in an automatic way. The parameters of the controller are determined by minimizing the error dispersion.