Nonlinear PID Control of a Factory Belt Drive System

Abstract

Belt drive systems offer a versatile solution for positioning motors relative to loads, reducing conveyor inertia and enabling quick responses in robotic applications. However, their flexible dynamics can compromise positioning accuracy. This trade-off between control simplicity and precision arises from the challenges of rejecting time-varying disturbances caused by belt flexibility and mitigating system resonance. To address these issues, this paper presents a comprehensive model of a belt drive conveyor system, incorporating a detailed DC motor model and a realistic friction model. This enhanced model is expected to improve the positioning accuracy of the belt-driven mechanism. High-capacity belt conveyors are essential for efficient bagasse transport in open-pit operations to meet boiler demands. This paper investigates such a conveyor system, including its structure and performance evaluation. The conveyor is driven by a DC motor, and a simulation model of the motor-drive assembly is developed to analyze transient behaviors like starting, speed adjustment, and braking. Belt drives have a long history in this industry but present significant challenges due to slippage, tension variations, and belt-pulley interactions, leading to nonlinear behavior, large vibrations, and complex contact dynamics. These issues are exacerbated in the Kassem sugar factory's belt drive system, which suffers from slow response and poor tracking accuracy due to the existing DCS control with simple ON/OFF mechanisms. Effective motion control for belt drives is crucial across various industries and is influenced by these factors