A Tutorial on Modelling and Control of Two-Wheeled Self-Balancing Robot with Stepper Motor

Abstract

In this paper we describe an approximate mathematical model for a stepper motor based two-wheeled self-balancing (TWSB) robot. We show the usage of this model in computer aided design of a digital controller to balance and to steer the robot. TWSB robots can be implemented using geared DC motors and stepper motors. The latter version is popular in recent years after the appearance of open-hardware design for stepper motor driver module, which was originally created for desktop 3D printers and CNC machines, and the ease with which stepper motors can be controlled with pulsed electrical signals. Even though many individuals had shared the design and computer codes for TWSB robots with stepper motors, to date there is still a lack of mathematical model for such machines being reported, even in academic publications. Almost all reported works on stepper motor based TWSB robots rely on empirical or trial-and-error approach to obtain a suitable feedback controller for balancing the machine. This paper intends to fill the gap, and the model and techniques described will be useful for engineers, researchers, educators and others who are building their own machines.

Keywords

• digital control
• modelling
• robot
• self-balancing
• scilab
• stepper motor