In this paper, an output feedback nonlinear control is proposed for a hydraulic system with mismatched modeling uncertainties in which extended state observer (ESO) and robust controller are synthesized via the backstepping method. The ESO designed to estimate not only unmeasured states but also uncertainties. stabilize closed-loop system. accounts nonlinearities (e.g., flow features of servovalve), parameter derivations unmodeled dynamics). Furthermore, theoretically guarantees prescribed...

Structured and unstructured uncertainties are the main obstacles in development of advanced controllers for high-accuracy tracking control hydraulic servo systems. For structured uncertainties, nonlinear adaptive can be employed to achieve asymptotic performance. But modeling errors, such as frictions, always exist physical systems degrade accuracy. In this paper, a robust integral sign error controller an synthesized via backstepping method motion rotary actuator. addition, experimental...

Structured and unstructured uncertainties always exist in physical servo systems degrade their tracking accuracy. In this paper, a practical method named adaptive robust control with extended state observer (ESO) is synthesized for high-accuracy motion of dc motor. The proposed controller accounts not only the structured (i.e., parametric uncertainties) but also nonlinear friction, external disturbances, and/or unmodeled dynamics). Adaptive uncertainty ESO are designed compensating them...

This paper presents an active disturbance rejection adaptive control scheme via full state feedback for motion of hydraulic servo systems subjected to both parametric uncertainties and uncertain nonlinearities. The proposed controller is derived by effectively integrating with extended observer backstepping method. law synthesized handle the remaining are estimated then compensated in a feedforward way. unique features that not only matched but also unmatched constructing two observers,...

This paper concerns high-accuracy tracking control for hydraulic actuators with nonlinear friction compensation. Typically, LuGre model-based compensation has been widely employed in sundry industrial servomechanisms. However, due to the piecewise continuous property, it is difficult be integrated backstepping design, which needs time derivation of model. Hence, rarely sets foot nondifferentiable models, such as model, Stribeck effects, although they can give excellent description and...

Velocity signal is difficult to obtain in practical electrohydraulic servomechanisms. Even though it can be approximately derived via numerical differentiation on position measurement, the strong noise effect will greatly deteriorate achievable control performance. Hence, how design a high-performance tracking controller without velocity measurement of significance. In this paper, adaptive proposed for To estimate unmeasurable signal, an extended state observer (ESO) that also provides...

This paper focuses on developing an advanced nonlinear controller for hydraulic system to achieve asymptotic tracking with various disturbances. To accomplish this study, a multilayer neural-networks (NNs) estimator is first developed improve the compensation accuracy of model-based feedforward control terms, which can greatly reduce uncompensated disturbance, then continuous robust integral sign error (RISE) approach effectively integrated NNs deal residual mismatched in RISE feedback gain...

The industrial gearboxes usually work in harsh and variable conditions, which results partial failure of gears or bearings. Accordingly, the continuous irregular fluctuations gearbox under conditions maybe increase intraclass difference reduce interclass for monitored samples. To this end, a new intelligent fault diagnosis method based on adaptive convolutional neural network (AIICNN) working is proposed. core proposed algorithm to apply designed constraints improve distribution differences...

The rotor-bearing system is widely used in various high-end electro-hydraulic equipment, which provides specific support, rotation, and other integral functions. However, the fluctuating working conditions of will cause more significant disordered fluctuations measured signals. This article proposes a new algorithm called multiscale deep graph convolutional networks (MS-DGCNs) to alleviate this problem. designed MS-DGCNs combines intra-class fine coarse-grained processing convolution...

In this article, an innovative backstepping controller for hydraulic systems is proposed to handle system uncertainties and accomplish specified performance tracking without violating the full-state constraints. To deal with uncertainties, extended state observers ESOsand adaptive law are integrated. ESOs structured estimate disturbances, whereas applied approximate unknown parameters. The estimated then incorporated into a constrained controller, ensuring that both prescribed transient...

Hydraulic manipulators are extremely complicated systems due to the highly nonlinear characteristics, strong coupling among multiple joints, and heavy modeling uncertainties, which greatly complicate high-performance tracking controller development compared with conventional driven by electrical motors. To overcome above obstacles, this article proposes a novel radial basis function neural network (RBFNN)-based adaptive asymptotic prescribed performance for <inline-formula...

Abstract Multilayer neural networks can approximate endogenous disturbances with relatively high accuracy. However, for multilayer‐neural‐network‐based control methods of high‐order uncertain nonlinear systems, hard to handle large exogenous especially mismatched types, complex controller scheme and so on, make them difficult be practical. Therefore, a novel high‐performance multilayer neurocontroller which simultaneously reject matched will proposed in this paper. Specially, strong...

Parametric uncertainty associated with unmodeled disturbance always exist in physical hydraulic systems, and complicate the advanced nonlinear controller design. In this paper, an adaptive compensation a robust integral of sign error (RISE) feedback is developed for high precise tracking control motion system. To handle both payload unknown parameters one controller, chain integrator system model first derived, RISE then proposed, which law synthesized to parametric term attenuate...

When performing periodic tasks, the modeling uncertainties will also present some periodicity. In this paper, by appropriately applying Fourier series approximation, a practical nonlinear adaptive repetitive controller is proposed for motion control of hydraulic servomechanisms to learn and compensate uncertainties. Robust term constructed effectively attenuate effect approximation errors, thus asymptotic tracking performance achieved. addition, robustness discussed with respect other...

Summary This paper addresses the output feedback tracking control of a class multiple‐input and multiple‐output nonlinear systems subject to time‐varying input delay additive bounded disturbances. Based on backstepping design approach, an robust controller is proposed by integrating extended state observer novel controller, which uses desired trajectory‐based feedforward term achieve improved model compensation based finite integral past values compensate for delay. The can simultaneously...

Continuous friction compensation along with other modeling uncertainties is concerned in this paper, to result a continuous control input, which more suitable for controller implementation. To accomplish task, practical method, named as robust integral of the sign error controller, synthesized differentiable model high-accuracy motion dc motor. reduce noise sensitivity and further improve tracking accuracy, desired technique employed proposed term depends on reference trajectory only, its...

A desired compensation adaptive controller is proposed in this paper for precision motion control of electro-hydraulic servo systems, with consideration the nonlinearity, modeling uncertainty, and especially severe measurement noise arising from actual state feedbacks deteriorating performance significantly. To alleviate noise, states model-based design are replaced corresponding values. Considering that general hydraulic system model contains unmatched uncertainties (e.g., unmodeled...

This paper deals with the high performance force control of hydraulic load simulator. Many previous works for are based on their linearization equations, but inherent nonlinear properties and uncertainties make conventional feedback proportional-integral-derivative not yield to high-performance requirements. In this paper, a system model is derived linear parameterization made adaptive control. Then discontinuous projection-based robust controller developed The proposed constructs an...