Abstract The main steering rudder surface of civil aircraft usually adopts the design redundant degree actuator channels to meet requirements high safety flight control systems. However, use main-main operating leads a force fight phenomenon, which can bring fatigue and other effects on structure even threaten safety. In this paper, system with three residual degrees main-main-main operation is...

This paper presents the application of recurrence plots (RPs) and recurrence quantification analysis (RQA) in model-based diagnostics of nonlinear systems. A detailed nonlinear mathematical model of a servo electro-hydraulic system has been used to demonstrate the procedure. Two faults have been considered associated with the servo valve including the increased friction between spool and sleeve...

This paper aims at the characteristics of nonlinear, time-varying and parameter coupling in a hydraulic servo system. An intelligent control method is designed that uses self-learning without model or prior knowledge, order to achieve certain effects. The quantity can be obtained current moment through continuous iteration strategy–value network, online self-tuning parameters realized. Taking s...

This paper discusses the possibility to use low-cost on/off valves instead of servo valves even in demanding servo applications. Different on/off control techniques are first reviewed and analyzed. Then the basic principles of suggested Digital Hydraulics technology are introduced and some tracking control results are presented. Results show that energy efficient and high-quality position and v...

In the paper, a fuzzy variable structure control with a harmonizing mechanism has been developed and applied to the positioning control of an electro-hydraulic servo system. The simulation experiment results show that the performance by using the controller is better than those by just only using either fuzzy controller or variable structure controller. In addition, it also demonstrates that it...

This paper focuses primarily on adaptive dynamic programming (ADP)-based tracking control of the hydraulic-driven flexible robotic manipulator system (HDFRMS) with varying payloads and uncertainties via singular perturbation theory (SPT). Firstly, dynamics is derived using a driven Jacobin matrix, which represents coupling between hydraulic servo-driven rigid–flexible established assumed mode m...