Attitude control for a combine harvester: A cascade scheme approach

Modern agricultural vehicles are complex machines that require many automatic controls. Combine harvesters are particularly challenging from a control perspective. A critical control problem in combines is chassis leveling. Keeping the chassis level with respect to the gravity enhances both the crop processing efficiency and the vehicle safety. This paper presents a leveling control algorithm based on switching hydraulic actuators. A gray-box system identification is first performed, and the regulator is designed as a two-layer cascade scheme. Closed-loop experimental tests on the real vehicle prove the effectiveness of the designed controller, showing a reduction of ≈ 40% in terms of root mean square error of the roll angle, with respect to an uncontrolled case.