Position Control Algorithm of Fuzzy Adaptive PID of Hydraulic Interconnected Suspension Under Load Impact Disturbance

Abstract

Position control accuracy of hydraulic interconnected suspension (HIS) for agricultural vehicle is unsatisfied under load impact conditions. In order to address this problem, advanced control methods were studied in this paper. The technical scheme of HIS was developed firstly. The transfer function from proportional valve spool displacement to hydraulic cylinder piston displacement was derived and then the parameters of the transfer function were also identified. The PID, sliding mode control (SMC) and fuzzy adaptive PID (FAPID) control algorithms were designed. The co-simulation of AMESim and SIMULINK was adopted to compare and analyze the control characteristics of the three algorithms. An experimental platform was also built to verify the improvement effect. The research conclusions show that when the HIS operates under load impact condition, for FAPID algorithm, the rise time is reduced by 0.27s, the maximum overshoot is reduced by 9.83mm, and the absolute value of average error is decreased by 62.62% compared with PID control algorithm. The response speed of SMC is the fastest, but there is a large chattering in the steady-state displacement. The designed FAPID control algorithm balances the advantages of fast response, high control precision and good stability, and the control performance is better than that of SMC and PID control algorithms. The research methods in this paper can provide reference value for position control accuracy improvement of hydraulic suspension.INDEX TERMS Fuzzy adaptive PID, hydraulic interconnected suspension, load impact, position control, sliding mode control. KAI HU was born in Kuiwen District, Weifang, Shandong, China, in 1990. He received the B.S. and M.S. degrees in vehicle engineering from the Shanghai University of Engineering Science, in 2012 and 2015, respectively. He is currently pursuing the Ph.D. degree with Nanjing Tech University. Since 2015, he has been a Research Assistant with the Nanjing Institute of Agricultural Mechanization. He is the author of more than 24 articles, and more than 30 patents. His research interests include the intelligent control technology and electro-hydraulic control technology. He won the national Scholarship for graduate students, in 2015. WENYI ZHANG was born in Danyang, Jiangsu, China, in 1966. He is a Master Student Supervisor and he is also the Department Head of the Nanjing Institute of Agricultural Mechanization, Ministry of Agriculture and Rural Affairs. He is the author of four books, more than 40 articles, and 65 patents. His research interests include intelligent control theory and application and electromechanical system integrated control. He is the Secretary-General of Rice Expert Group, Ministry of Agriculture and Rural Affairs of China, and the Director of Jiangsu Agricultural Society.