Implementing a discrete control system to command a prototype-bar position using a brushless motor propeller

Abstract

The design and construction of a motor-propeller-rectangular bar system prototype is proposed in this project. Components selection, system integration and verification are described, as well as the control strategy used for the system. The motor-propeller-bar prototype consists of a rectangular bar fixed on one of its ends using a hinge, allowing the vertical movement on the other edge (one degree of freedom). A propeller allocated at the end of the bar creates the thrust force which generates the movement. The propeller is powered by a brushless motor for which its rotational speed controls the thrust force exerted to the complete system. The position of the bar is given by a distance measuring sensor that provides the distance between a set reference point and the actual point where the bar is positioned. The system control was carried out via an Arduino Board, a controller was implemented after analysing the data by using the MatLab Software environment. After determining the transfer function of the system with MatLab by using the tools called System Identification and PID Tuner, a PI close-loop control was defined and the proportional and integration constants were transferred to the controller code for the Arduino. These variables had to be recalculated using MatLab Simulink in order to increase the efficiency of the control. The desired position of the prototype could then be set in using the Arduino interface. The aim of this project is to summarize the knowledge needed to design and construct the prototype of the motor-propeller-rectangular bar system and to implement its control system. In addition, the results of the real system are compared to the system’s model created in MatLab Simulink.