'Position control of a linear axis with Arduino board and Matlab interface'

The topic of the thesis concerns the development of the position control of a linear axis, an axis composed of an electric motor controlled in position and a screw that transform the rotary and linear motion. The motor, in particular, is a DC motor; the sensor to be used to control the position and speed is an encoder. The type of control is a PID carried out by means of an Arduino Board interfaced with Matlab. The thesis project develops in thre part: 1)A brief introduction of the theory on the DC motors and PID controller, its origin, its applicability, its tuning and all the adjustment methods: manual tuning, open loop Ziegler-Nichols methond and Relay method; 2)The construction of the model starting from DC motor identification and its analysis trough the theory of the PWM and its possible application in controlling the motor. 3)Pratical analysis starting from the equipment description: a system alimented by Arduino, which is an open source electronic board that includes a microprocessor, digital and analog input/output and some interfaces such as incremental encoders. The third part has been developed in the Dimeas department of the Politecnico of Turin in three months and the first step was to interfaceMatlab with Arduino in order to manually control the motor via PC and to read the position and the speed of the incremental encoder. To ensure that Arduino communicates directly with the PC, a Matlab interface was created through the GUI (Graphical user interface), thus allow to control the direction of rotation and speed trough some point-and-click control over software application. Two different code were written in order to perform different tests. The main part of the thesis is concentrated in the final part, where it is reported the experimental phase which allow us to stabilize the system and the obtained results are highlighted.