AAU Student Projects - visit Aalborg University's student projects portal
A master's thesis from Aalborg University
Book cover


Realizing Third Order Sliding Mode Control for a Hydraulic Multibody Servo System

Authors

;

Term

4. term

Publication year

2013

Submitted on

Pages

171

Abstract

Denne afhandling sammenligner en tredjeordens sliding mode-styringsalgoritme (3SMC) med en avanceret, industrilignende lineær styring til en hydraulisk servo på en CASE 580 rendegraver. I denne maskine skaber en asymmetrisk, ikke-matchende ventil–cylinder-opsætning samt koblede bevægelser mellem flere komponenter en stærkt ikke-lineær opførsel, som gør præcis bevægelsesstyring vanskelig. For at udforme en robust lineær referencekontrol og muliggøre en fair sammenligning blev der udviklet en detaljeret ikke-lineær model, der dækker mekanik, hydraulik og kraftenhed, og som danner grundlag for simulering af begge styringers ydeevne. Styringerne blev derefter vurderet under realistiske, industrilignende arbejdsbetingelser. Resultaterne viser, at den lineære styring opnår en lidt bedre sporingspræstation, dvs. den følger de ønskede bevægelser en anelse mere præcist. Afhandlingen afslutter med forslag til, hvordan 3SMC kan forbedres.

This thesis compares a third-order sliding mode control (3SMC) algorithm with an advanced, industry-like linear controller for a hydraulic servo on a CASE 580 backhoe loader. In this machine, an asymmetric, unmatched valve–cylinder setup and the interaction of multiple moving parts lead to strongly nonlinear behavior, which makes precise motion control challenging. To design a robust linear reference controller and enable fair comparisons, a detailed nonlinear model covering the mechanics, hydraulics, and power unit was developed and used to simulate the performance of both controllers. The controllers were then evaluated under realistic, industry-like working conditions. The results show that the linear controller achieves slightly better tracking performance, meaning it follows desired motions a bit more accurately. The thesis concludes with suggestions on how to improve the 3SMC approach.

[This abstract was generated with the help of AI]