Cascade control algorithm of test bench for studying loadsensing electrohydraulic steering systems

The paper presents the design and synthesis of a three-loop cascade control system with a digital PI controller intended for installation in a test bench for load-sensing electrohydraulic steering units. The structure and layout of both the hydraulic system and the control system are shown. The cascade control system consists of three controllers for measurable variables: proportional spool valve position, steering velocity and steering cylinder position. The developed control algorithm is embedded into a 32-bit microcontroller for mobile applications. Experimental studies have been carried out to present the performance of the entire electrohydraulic system. The developed control algorithm will serve as a basis for further study of the system with advanced control techniques implementable in low speed mobile machines.