In this study, we introduce an advanced framework for state estimation in electro-hydraulic systems, utilizing a structurally adapted Kalman filter. The proposed model was designed to enhance estimation accuracy and robustness under dynamic load variations and evolving measurement conditions. A notable feature of the approach is the algebraic resolution of one system state during each iteration, enabling the seamless inclusion of variables that are otherwise difficult to measure, without disrupting the model’s linear formulation. In addition, the dynamics of the load torque are empirically characterized through a regression-based model derived from experimental observations. The framework integrates adaptive mechanisms for updating the model and measurement error covariance matrices, facilitating the real-time accommodation of system nonlinearities and environmental changes. Experimental results are presented in different operating modes, reflecting characteristic dynamic movements. They show that the method reduced the root mean square error (RMSE) when estimating angular velocity between five and more than six times, depending on the mode. When evaluating the load torque, even in modes with a sharply changing load, the RMSE value remains stable below 0.05 Nm, which indicates the absence of systematic drift and high stability of the estimates. This confirms the stable operation of the algorithm in dynamic conditions and its applicability in real systems.

This article proposes an integrated adaptive algorithm to control the accuracy and reliability of linear motion in electrohydraulic systems operating in dynamic modes and external loads. This algorithm has a multilevel parallel structure in which the physical model, extended measurement information, internal adaptive parameters, and the current of measurement and model uncertainties are combined and synchronized within a single loop. The proposed structure allows the real-time extraction of information about hard-to-determine dynamic characteristics of the electrohydraulic process, which is used to maintain consistency between the mathematical model and the actual behavior of the system, including in the case of rapidly changing modes and load variations. In addition, a functional observation layer for assessing the quality of measurement information is introduced, through which the sensitivity of adaptive mechanisms is managed, and the stability of the algorithm is maintained under degraded measurement conditions. Experimental results demonstrate a significant reduction in dynamic error and a sustainable improvement in the quality of tracking relative to a basic electrohydraulic system without algorithmic correction. This confirms the applicability of the proposed approach to real energy and industrial systems.

This paper presents a demonstration experimental test bench for investigating the dynamic characteristics of an electropneumatic positioning system with High Speed Pneumatic Valves (HSPV) and Pulse Width Modulation (PWM) control. A specialized virtual instrument has been developed for real-time control, data acquisition, and processing. The transient response of the electropneumatic positioning system is examined under various single-step input signals with frequencies ranging from 30 Hz to 70 Hz and varying duty cycles from 30% to 90%. The results are presented graphically, demonstrating that the system exhibits better linear characteristics compared to conventional pneumatic actuation systems.

The article presents an accurate mathematical model of an electro-pneumatic drive system for positioning a pneumatic cylinder with a double-acting rod, controlled by PWM and four high speed On/Off pneumatic valves. The main elements of the system are included in the model: screw compressor, high-speed pneumatic valves, pneumatic cylinder with double-out rod, PID controller. A simulation of the pneumatic positioning system was carried out using the Simscape language in MATLAB. The system is built using the Simscape Foundation gas domain, implementing simulations of piston rod displacement. An analysis of the results obtained and the simulation model is performed.

This paper presents mathematical models of flow through electropneumatic valve, it is an analysis of existing publications by various authors. The presented models are discussed and described in detail and the conditions for their application to different types of electropneumatic valve designs are presented. Graphical relationships showing the flow through the valves are presented.

This paper presents an experimental investigation into the frequency response of an electropneumatic positioning system, which includes a rodless pneumatic cylinder and four 2/2-way high speed pneumatic valves operated via pulse width modulation. The experimental procedures are captured and analyzed in real-time using a dedicated virtual instrument. The amplitude and phase Bode plots for the electropneumatic positioning system were obtained through experimentation and subsequently analyzed, leading to the identification of the system's critical frequency. The findings are illustrated through various graphs.