Session: Controls 2

Paper Number: 111576

111576 - Precision Motion Control of an Independent Metering System With an Adaptive Piecewise Polynomial Valve Model 

The independent metering approach decouples the meter-in and meter-out flow, offering more flexibility in the motion control of the hydraulic actuator. In such a system, two or more proportional control valves are used, which means that uncertainties and nonlinearities of the valves have an increased impact on control performance compared with the conventional system.In our previous study, a polynomial flow model was introduced to improve valve modeling accuracy, considering nonlinear flow gain and inner leakages.However, for those valves with piecewise spool notch shape design, the flow characteristics vary greatly in different input zone, which cannot be modeled well with only one polynomial. In this paper, to better characterize the segmental feature, a piecewise polynomial valve flow model is introduced. Based on the prior knowledge of the spool notch shape or identification data, the valve flow model is divided into different pieces, and polynomials of different orders are used in each part. The adaptive robust approach is applied for motion control, pressure control, and parameter estimation. The motion control performance and parameter estimation results are investigated through simulation and experiments.It shows that the proposed method can better describe the piecewise flow gain of the valve compared with the previously proposed method, and fewer parameters are used compared with the piecewise linear model.

Presenting Author: Chen Li Zhejiang University

Presenting Author Biography: Chen Li received the B.Eng. degree in transport equipment and control engineering from Central South University, Changsha, China, in 2018. He is currently working toward the Ph.D. degree in Mechatronic Engineering at the College of Mechanical Engineering, Zhejiang University, Hangzhou, China.