Design of Position Control Method for Pump-Controlled Hydraulic Presses via Adaptive Integral Robust Control

Abstract

This paper takes the position control performance of pump-controlled hydraulic presses as the research object. The control methods are designed respectively for the two motion stages of rapid descent and slow descent of hydraulic presses in order to improve the control performance of the system. First of all, the accuracy model of the pump-controlled hydraulic presses position servo system (the pump-controlled hydraulic presses position servo system, which is called PCHPS) and its MATLAB/Simulink simulation platform are established. Based on the theoretical analysis and experimental data, the interference factors affecting the tracking accuracy and positioning accuracy of the PCHPS are analyzed. Then, an adaptive integral robust control (the adaptive integral robust control, which is called AIRC) for PCHPS is designed to reduce the influence of nonlinear factors on the system, and the effectiveness of the controller is verified by simulation. Finally, the position control experiment of PCHPS is designed, and the experimental results show that the AIRC can effectively reduce nonlinear factors such as unknown interference in the slow-down stage of the system. The positioning accuracy is raised to within 0.008 mm, which improves the process level of the hydraulic presses.

A Singular Perturbation Theory-Based Composite Control Design for a Pump-Controlled Hydraulic Actuator with Position Tracking Error Constraint

“…By repeating the procedure in (25), we can obtain that the quasi-steady-state λ that becomes the solution of ψ(t, ξ, λ, u s , 0) = 0. It is easy to obtain that:…”

“…Two DOBs are incorporated to provide estimates of the matched and mismatched uncertainties. (2) Unlike the existing works [14,25,26], the PHA is decomposed into slow mechanical and fast hydraulic subsystems from a two-time scale perspective. Therefore, the control task is reduced to investigating the two reduced-order subsystems.…”

Observer-Based Approximate Affine Nonlinear Model Predictive Controller for Hydraulic Robotic Excavators with Constraints

“…However, since robotic excavators typically use hydraulic systems as their power source, achieving high-performance trajectory tracking remains challenging due to the nonlinear and multi-constrained features [5]. Many control methods, such as the improved PID control [6][7][8], self-tuning pressure-feedback control [9], adaptive robust control [10], intelligent control [11,12], and so on, have been proposed to deal with the nonlinearity, time-variance, and parameter uncertainty of hydraulic robotic excavators. However, they find it difficult to meet the multi-constraint features of electro-hydraulic systems [13].…”