Effect of leakage in electrohydraulic servo systems based on complex nonlinear mathematical model and experimental results

Abstract

This paper looks into the background of the internal leakage effect on the dynamic behavior of an electrohydraulic servo positioning system. The electrohydraulic servo systems are widely used in precise control at high forces, but the overall quality of this servo control could be impaired by faults in the system. There could be several defects which have effect on the system response, but this work points to the effect of internal leakage of the hydraulic cylinder because this error cannot be easily detected. To show the effect of internal leakage on electrohydraulic servo system a complex nonlinear mathematical model considering the leakage of the hydraulic cylinder is used. The work herin demonstrates the relationship between internal leakage and the dynamic behaviour of the servo positioning system. Laboratory test results are used to verify the conclusions drawn from the mathematical model of the complete servo positioning system.