Study on the compensation control of electro-hydraulic servo force loading in nonlinear variable load condition

Sang, Yong; Sun, Weiqi

doi:10.1177/0959651818808867

Cited by 4 publications

(3 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…10 During this process, a phenomenon called sand liquefication will occur that the soil sample first changes into liquid and then back into solid periodically. 27 This will cause the stiffness of soil samples show different form of nonlinearities even under the same loading conditions and its range can be extremely wide. Therefore, the triaxial apparatus has a huge advantage for reflecting most types of loads over other existing products and can be very representative in mechanical engineering.…”

Section: A Practical Nonlinear Variable Load Of the Electrohydraulic ...mentioning

confidence: 99%

“…The nonlinearities of the load in Figure 4 are caused by the sand liquefaction. 27 During this phenomenon, the modulus of the soil sample becomes extremely small when the load acting on the soil sample reduces that the soil starts to turn into liquid. Considering the position as xp and the force as yu in the section Basic Loads of the Force Closed-Loop Electrohydraulic System , the phenomenon leads c to an extremely small value when xp<0.…”

Section: A Practical Nonlinear Variable Load Of the Electrohydraulic ...mentioning

confidence: 99%

See 1 more Smart Citation

Global identification and compensation of nonlinear variable load for an electrohydraulic system

Sun

Sang

Duan

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part C:

Self Cite

View full text Add to dashboard Cite

In an electrohydraulic system, the load is an external factor that cannot obtain similar results by repetitive experiments compared with other internal factors. It can work a great change in an extremely short time determined by the characteristics of the loaded object, which is more difficult to be identified timely and compensated precisely. This paper first built the mathematic model of the electrohydraulic system containing load characteristics and illustrated most kinds of basic loads that possibly occur in it. Then, a practice nonlinear variable load composed of these basic loads is presented, and the corresponding effect to the electrohydraulic system is analyzed. Based on the summary of load, a nonlinear variable load compensation controller (NVLCC) with neural networks is proposed to identify the mathematic model of the electrohydraulic system. The nonlinear variable load is considered as a part of the model to be globally identified, and an adaptive sliding mode control method is combined to quickly converge the errors of system state variables. The compensation effectiveness is demonstrated by both rigid step response and dynamic sine response in the simulations, and the actual improvements are verified with the experiments using three different typical linear loaded objects and a representative nonlinear loaded object.

show abstract

Section: A Practical Nonlinear Variable Load Of the Electrohydraulic ...mentioning

confidence: 99%

Section: A Practical Nonlinear Variable Load Of the Electrohydraulic ...mentioning

confidence: 99%

Global identification and compensation of nonlinear variable load for an electrohydraulic system

Sun

Sang

Duan

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part C:

Self Cite

View full text Add to dashboard Cite

show abstract

“…22,27–30 Although the observer-based hybrid algorithm can achieve high control performance, it also increases the complexity of the algorithm and the difficulty of controller parameter tuning. In recent years, intelligent control algorithm has also been applied to hydraulic servo control system such as fuzzy technology, 31 neural network 32 and learning algorithms 33,34 . Intelligent control does not need to consider the mathematical model of the controlled object, but it needs to design a complex rule base or conduct a lot of training to achieve good control effect.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear adaptive position control of hydraulic servo system based on sliding mode back-stepping design method

Wang

Zhang

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part I:

View full text Add to dashboard Cite

Electro-hydraulic servo system is often affected by parameter uncertainties and mismatched random disturbances, which are two major obstacles to achieving high-performance servo control. In this article, a sliding mode adaptive controller is proposed to solve these two problems. The proposed controller employs sliding mode control method to eliminate unknown mismatched disturbances, adaptive design to deal with parametric uncertainties. A new smooth and continuous sliding mode control law is proposed to solve the design conflicts between sliding mode control technology and back-stepping adaptive control technology. The stability of the algorithm is proved based on the Lyapunov theory. Theoretically, the algorithm can make the position tracking error arbitrarily small. Through the co-simulation platform of AMESim and MATLAB/Simulink, the control performance of the developed control algorithm is verified. The results show that the developed sliding mode adaptive controller scheme can achieve high-performance tracking under the condition of parametric uncertainties and unknown mismatched disturbances.

show abstract

Analysis on parametric vibration of hydraulic opposing cylinders controlled by a servo valve considering pressure pulsation

Yuan

Wang

Zhu

et al. 2022

Trans. Can. Soc. Mech. Eng.

View full text Add to dashboard Cite

During the working process of the system of hydraulic opposing cylinders controlled by a servo valve, the fluid equivalent stiffness changes dynamically due to the pressure pulsation of the pump source. Therefore, the transmission system has obvious nonlinear effects, and its dynamic performance is difficult to improve further. Thus, a nonlinear dynamic model of the system of hydraulic opposing cylinders controlled by a servo valve was established. By using the multiscale method, the steady-state approximate solutions of the primary resonance and the combination resonance of the system were derived to reveal their characteristic laws. The results showed that the dominant frequency of the system's primary resonance is the frequency of the external excitation source, and the dominant frequency of the system's combination resonance is the sum of the natural frequency of each order and the fluctuation frequency of the fluid equivalent stiffness. The amplitude of the combination resonance was smaller than that of the primary resonance. The maximum error between the theoretical natural frequency and the experimental modal frequency was 3.77%, which verified the correctness of the system's nonlinear dynamic model. The research can provide a theoretical reference for the dynamics optimization design of the hydraulic transmission system.

show abstract

Study on the compensation control of electro-hydraulic servo force loading in nonlinear variable load condition

Cited by 4 publications

References 25 publications

Global identification and compensation of nonlinear variable load for an electrohydraulic system

Global identification and compensation of nonlinear variable load for an electrohydraulic system

Nonlinear adaptive position control of hydraulic servo system based on sliding mode back-stepping design method

Analysis on parametric vibration of hydraulic opposing cylinders controlled by a servo valve considering pressure pulsation

Contact Info

Product

Resources

About