Physical modeling and control of self-balancing platform on a cart

Abstract

This paper demonstrates a self-balancing platform with 2-degrees of freedom on a cart which is generally treated as inverted pendulum for simplicity. The system can be used in various transportation devices, delivery and stabilization systems and is particularly suitable for working in outdoor where the surface of ground is not flat or structured. The platform can freely rotate with the help of a ball and socket joint at its center. Lateral and longitudinal movements are controlled by two servomotors for each axis. As the cart moves on slope or on a rough terrain, the instantaneous tilt of the platform is measured by a gyroscope assembly which is compared with the desired orientation of the platform and can take corrective measure for platform up to 5 degrees in both axes. In this paper, physical modeling method is used for rapid simulation of system and mathematical relationship between platform tilt with respect to servomotor's rotation angle is developed. Proportional-integral-derivative (PID) controller is used for desired smooth operation and jerk attenuated balance of the platform. Comparative study of performance of the system for the physical model developed and the one that is implemented is made.