Research on Position / Velocity Synergistic Control of Electro Hydraulic Servo System

2020 ◽  
Vol 13 (4) ◽  
pp. 366-377 ◽  
Author(s):  
Bingwei Gao ◽  
Yongtai Ye
Keyword(s):  
Position Control ◽  
Control Method ◽  
Control Object ◽  
Servo System ◽  
Control Effect ◽  
Positioning Accuracy ◽  
Feed Forward ◽  
Neural Network Controller ◽  
Hydraulic Servo ◽  
Hydraulic Servo System

Background: In some applications, the requirements of electro-hydraulic servo system are not only precise positioning, but also the speediness capability at which the actuator is operated. Objective: In order to enable the system to achieve rapid start and stop during the work process, reduce the vibration and impact caused by the change of the velocity, at the same time improve the positioning accuracy, and further strengthen the stability and the work efficiency of the system, it is necessary to perform the synergistic control between the position and the velocity of the electrohydraulic servo system. Methods: In order to achieve synergistic control between the position and the velocity, a control method of velocity feed-forward and position feedback is adopted. That is, based on the position control, the speed feed-forward is added to the outer loop as compensation. The position control adopts the PID controller, and the velocity control adopts the adaptive fuzzy neural network controller. At the same time, the position and velocity sensors are used for feedback, and the deviation signals between the position and the velocity obtained by superimposing the feedback are used as the final input of the control object, thereby controlling the whole system. Results: The control effect of the designed position / velocity synergistic controller is verified by simulation and experiment. The results show that the designed controller can effectively reduce the vibration and impact caused by the change of the velocity, and greatly improve the response velocity and the position accuracy of the system. Conclusion: The proposed method provides technical support for multi-objective synergistic control of the electro-hydraulic servo system, completes the requirements of multi-task operation, improves the positioning accuracy and response velocity of the electro-hydraulic servo system, and realizes the synergy between the position and the velocity. In this article, various patents have been discussed.

HYBRID ITERATIVE LEARNING CONTROL FOR POSITION TRACKING OF AN ELECTRO HYDRAULIC SERVO SYSTEM

2019 ◽  
Vol XVI (2) ◽  
pp. 31-42
Author(s):  
Mansoor Zahoor Qadri ◽  
Ahsan Ali ◽  
Inam-ul-Hassan Sheikh
Keyword(s):  
Iterative Learning Control ◽  
Position Control ◽  
Servo System ◽  
Learning Control ◽  
Iterative Learning ◽  
Feed Forward ◽  
Percent Improvement ◽  
Hydraulic Servo ◽  
Hydraulic Servo System ◽  
Feed Forward Controller

Accurate position control of an electro hydraulic servo system (EHSS) is a challenging task due to inherent system nonlinearities, parametric variations and un-modelled dynamics. Since feedback controllers alone cannot provide perfect tracking control, an integration of feedback and feed forward controller is required. A cascaded iterative learning control (ILC) technique for position control of EHSS is proposed in this paper. ILC is a feed forward controller which modifies the reference signal for a feedback fractional order proportional-integral-derivative (PID) controller by learning through current control input and previous error obtained through trails. Unlike other feed forward controllers, ILC works on signal instead of system which eliminates the need of complete knowledge of the system. As compared to other controllers, the proposed technique provides fast convergence without the need of reconfiguring the existing control loop. Simulation and experiments revealed the effectiveness of the proposed technique for EHSS. The obtained results indicated eight percent improvement in rise time and nearly twenty one percent improvement in the settling time.

MRAC for Direct Drive Electronic-Hydraulic Servo System

2012 ◽  
Vol 433-440 ◽  
pp. 4142-4148
Author(s):  
Lei Han ◽  
Hong Jie Wang ◽  
De You Li ◽  
Yang Yao
Keyword(s):  
Position Control ◽  
Control Method ◽  
Servo System ◽  
Mathematic Model ◽  
Order System ◽  
Direct Drive ◽  
Actual System ◽  
Hydraulic Servo ◽  
Hydraulic Servo System ◽  
Time Domain Response

In order to improve the accuracy, stability and rapidity of response, the paper built the mathematic model, and designed the high order system following the low order model based on Popov Hyperstable theory. Then applied this control method and PID method in actual system, compared them in time domain response. The result approves that the system owns better rapid and stable characteristics, satisfying the requirement when the direct drive electronic-hydraulic position control system changes its conditions. Further, improves that the theory is correct, certificates that the MRAC is very adaptive to the direct drive electronic-hydraulic servo system.

System identification and robust position control for electro-hydraulic servo system using hybrid model predictive control

2017 ◽  
Vol 24 (18) ◽  
pp. 4145-4159 ◽  
Author(s):  
Hai-Bo Yuan ◽  
Hong-Cheol Na ◽  
Young-Bae Kim
Keyword(s):  
System Identification ◽  
Model Predictive Control ◽  
Predictive Control ◽  
Position Control ◽  
Servo System ◽  
Model Parameters ◽  
Integral Control ◽  
Hybrid Controller ◽  
Hydraulic Servo ◽  
Hydraulic Servo System

This paper examined system identification using grey-box model estimation and position-tracking control for an electro-hydraulic servo system (EHSS) using hybrid controller composed of proportional-integral control (PIC) and model predictive control (MPC). The nonlinear EHSS model is represented by differential equations. We identify model parameters and verify their accuracy against experimental data in MATLAB to evaluate the validity of this mathematical model. To guarantee improved performance of EHSS and precision of cylinder position, we propose a hybrid controller composed of PIC and MPC. The controller is designed using the Control Design and Simulation module in the Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW). A LabVIEW-based experimental rig is developed to apply the proposed controller in real time. Then, the validity and performance superiority of the hybrid controller were confirmed by comparing them with the MPC and PIC results. Results of real-life experiments show improved robustness and dynamic and static properties of EHSS.

scholarly journals Nonlinear Adaptive Robust Control of the Electro-Hydraulic Servo System

2020 ◽  
Vol 10 (13) ◽  
pp. 4494 ◽  
Author(s):  
Lijun Feng ◽  
Hao Yan
Keyword(s):  
Robust Control ◽  
Position Control ◽  
External Disturbance ◽  
Servo System ◽  
Adaptive Robust Control ◽  
Superior Performance ◽  
Parametric Uncertainties ◽  
State Equations ◽  
Hydraulic Servo ◽  
Hydraulic Servo System

This paper focuses on high performance adaptive robust position control of electro-hydraulic servo system. The main feature of the paper is the combination of adaptive robust algorithm with discrete disturbance estimation to cope with the parametric uncertainties, uncertain nonlinearities, and external disturbance in the hydraulic servo system. First of all, a mathematical model of the single-rod position control system is developed and a nonlinear adaptive robust controller is proposed using the backstepping design technique. Adaptive robust control is used to encompass the parametric uncertainties and uncertain nonlinearities. Subsequently, a discrete disturbance estimator is employed to compensate for the effect of strong external disturbance. Furthermore, a special Lyapunov function is formulated to handle unknown nonlinear parameters in the system state equations. Simulations are carried out, and the results validate the superior performance and robustness of the proposed method.

Simulations and Experiments on the Force Control of Hydraulic Servo System for Hydraulic Robots

2016 ◽  
Vol 826 ◽  
pp. 128-133 ◽  
Author(s):  
Hyo Gon Kim ◽  
Jong Won Lee ◽  
Yong Ho Choi ◽  
Jeong Woo Park ◽  
Jin Ho Suh
Keyword(s):  
Force Control ◽  
High Performance ◽  
Control Method ◽  
Servo System ◽  
Force Density ◽  
Hydraulic Actuator ◽  
Underwater Robots ◽  
Heavy Load ◽  
Hydraulic Servo ◽  
Hydraulic Servo System

Because hydraulic actuator has higher power and force density, it is normally used in heavy load manipulator robots and industrial equipment which require high torque. Also, the hydraulic actuator is applied to underwater robots that need high performance maneuver in underwater operations. The force control has benefits to those kind of robots to ensure compliance with user or environment. However, the hydraulic actuator is difficult to control forces due to the non-linearity characteristic of the hydraulic servo system. In this paper, we propose a force control method with compensation of force derivative and natural velocity feedback. We also describe a method of applying it to the real system. In order to evaluate the effect of the proposed control method, the simulations and experiments were performed.

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