Model-Based Design and Validation of a Gain-Scheduled Position Control System for Electro-Hydraulic Utility Dump Trailers

Hydraulic dump trailers are widely used in heavy machinery across many industries (e.g. construction, landscaping, agriculture, property maintenance) to quickly and efficiently transport and unload various types of materials. This necessitates different bed positions for different materials to ensure complete and safe drop-off. To this end, bed position control is utilized to provide controlled and precise unloading, preventing structural damage to the trailer frame, bed tip-overs, and free falls when the bed is being lowered and ensuring safety for the operators. Hydraulic systems are highly complex and non-linear, therefore simple linear controllers are not equipped to meet or maintain the required performance across the entire range of operating points of the system. For the purposes of this thesis a gain-scheduled PI controller that adjusts its proportional and integral gains in real time based on the desired angle of the bed and the load present on the bed was developed. The controller was developed in MATLAB/Simulink and validated via simulations, after which Embedded Coder in Simulink was utilized to generate code for the controller to be deployed on a Microchip board to perform PIL tests.