Modeling, control design and experimental automatic calibration of a leveling system for combine harvesters

The design of a production-grade control system is a complex and costly process, spanning from modeling to design and end-of-line tuning. This paper deals with the design of a combine chassis leveling control system. Starting from the identification of a gray box model, a two-layer cascade regulator is designed to control the body roll and pitch angles. In addition, an automatic, data driven tuning protocol that cuts down the time needed for the traditional manual tuning procedure is proposed. Less than 50 iterations are required to obtain a robust and effective controller calibration; a set of validation tests on different proving grounds completes the investigation, showing the controller effectiveness.