Application of self-tuning fuzzy proportional–integral–derivative control in hydraulic crane control system

Wenrui Hao,Jiangming Kan

doi:10.1177/1687814016655258

Abstract

Generally, pressure oscillation has negative effect on hydraulic crane system which requires high dynamic stability under a flexible operating condition. In order to reduce the hydraulic pressure oscillation, a self-tuning fuzzy proportional–integral–derivative control strategy is proposed for improving the control performance of hydraulic crane. In this article, a fuzzy proportional–integral–derivative controller which consists of a proportional–integral–derivative controller and a fuzzy inference unit with two inputs and three outputs is designed for valve control. Both fuzzy proportional–integral–derivative control and traditional proportional–integral–derivative control are simulated using MATLAB based on the model of hydraulic crane. Simulation experiments are conducted with different crane tip velocities. The experimental results show that pressure amplitude reduced about 25% at low velocity and pressure oscillation of hydraulic cylinder is suppressed comparing with traditional proportional–integral–derivative controller. In addition, fuzzy proportional–integral–derivative control enables a smoother variation and a higher accuracy in changing processes of joint angle and crane tip position. The performance of the hydraulic crane is improved.

Highlights

With advancement of industrialization, different types of hydraulic machines have been utilized in many aspects such as automobile industry, forestry, and aerospace industry.[1]
Hydraulic cranes work as lifting machines which are used in applications operating under high pressure and School of Technology, Beijing Forestry University, Beijing, China
A self-tuning fuzzy PID control method is presented by combining fuzzy control with PID controller for suppressing pressure oscillation and improving the performance of hydraulic crane system

Summary

Introduction

Different types of hydraulic machines have been utilized in many aspects such as automobile industry, forestry, and aerospace industry.[1]. Based on the relation between natural frequencies and dynamics of manipulator, Kovanen and Handroos proposed a control method that calculated the lowest frequency of crane and filtered the higher frequencies by piston positions and mass loads. Yang proposed an improved proportional–integral (PI) control algorithm that combined fuzzy set-point weighting with the PI controller to reduce the lowfrequency hydraulic–mechanical oscillations.[11] When focus on these studies, both control accuracy and pressure oscillation are important issues for hydraulic crane. A self-tuning fuzzy PID control method is developed to reduce pressure oscillation, and to improve the performance of hydraulic crane system. A2 dxp dt ð7Þ where Eoil denotes the bulk modulus of oil elasticity; V1 and V2 are dynamic volumes in two sides of the cylinder; xp is the piston position; A1 and q1 denote the cross-sectional area and input flows of chamber without rod, respectively; A2 and q2 denote the cross-sectional area and output flows of chamber with rod, respectively; qint is the internal leakage flow; and qext is the external leakage flow

Design of fuzzy PID controller

Design of fuzzy control rules

Findings

Conclusion