Interactive Analysis of Closed Loop Electro-hydraulic Control Systems

Abstract

Without exhaustive system simulation, using full featured software, predicting electro-hydraulic control system performance represents a challenge for many system designers. In this paper, an introductory study has been presented as a preliminary stage for an ultimate goal, which is developing cost effective Interactive Electro-hydraulic Closed Loop System Analyzer (IEHCLSA). IEHCLSA is software aiming ultimately, through several modules in further developments, to solve for the static and dynamic characteristics of a controlled hydraulic actuator in a feedback loop fashion. This study shows in a systematic calculation approach how to properly calculate the pressure, flow and power required to achieve certain acceleration/deceleration rate while a cylinder is moving. The study will be associated with the first version of the software, which will be used to solve this part of the problem interactively. The following set of design parameters will be used as inputs to the stream of the calculations, the hydraulic cylinder dimensions, equivalent moving mass, volumes of the hydraulic lines, hydraulic fluid bulk modulus, required deceleration/acceleration rate and the external force distribution over the cylinder stroke. The calculation outcome will be hydraulic cylinder stiffness, natural frequency, flow and pressure requirements. Using such software may reduce the effort, time and cost of hydraulic system prototyping.