scholarly journals Research on the Nonlinear Characteristic of Flow in the Electro-Hydraulic Servo Pump Control System

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 814
Author(s):  
Tiangui Zhang ◽  
Gexin Chen ◽  
Guishan Yan ◽  
Cheng Zhang ◽  
Yuan Li ◽  
...  
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
Dead Zone ◽  
Servo Motor ◽  
Saturation Zone ◽  
Output Displacement ◽  
Positive Displacement ◽  
System Flow ◽  
Displacement Pump ◽  
Hydraulic Servo

In an electro-hydraulic servo system, the system flow is used as an intermediate variable to control the output displacement/force/speed of the actuator, and it plays the role of a medium for energy transmission and conversion. Therefore, the control of the system flow is the essence of state control for the system actuator. The purpose of this paper is to study the non-linear characteristics of pump control system flow and pave the way for high-performance control of the system. Based on the flow partition idea, the system output flow is divided into the dead zone, load zone, and saturation zone. We establish a mathematical model of the hydraulic system to analyze and study the effect of the nonlinear characteristics of the servo motor and the positive displacement pump on the system flow partition characteristics. We focus on the effects of the positive displacement pump shear flow internal leakage, pressure difference flow internal leakage, oil compression, servo motor rotation friction, and servo motor torque reserve rate on the system flow output, and analyze the partition characteristics of the system flow under different working conditions. We provide a theoretical basis for a high-precision control strategy for a hydraulic system.

Research on the Relationship between Speed Control System and Electromechanical Oscillations

2015 ◽  
Vol 710 ◽  
pp. 47-52 ◽  
Author(s):  
Ya Qing Zhu ◽  
Min Zhong ◽  
Yu Jia Ma ◽  
Feng Ping Pan ◽  
Ling Ling Shi ◽  
...  
Keyword(s):  
Control System ◽  
Steam Turbine ◽  
Time Constant ◽  
Response Rate ◽  
Speed Control ◽  
Servo Motor ◽  
Speed Control System ◽  
Hydraulic Servo ◽  
The Impact ◽  
The Relationship

The system damping of electric power systems is influenced by factors of many aspects. In this paper, we analyzed the impact of speed control system on the damping of the whole system in consideration of the Pole-Zero Analysis. The result shows that simple speed control would damp the oscillation, while the power-frequency control would excite the oscillation. Furthermore, the effect of steam turbine response rate on the system damping is analyzed. The time constant of hydraulic servo-motor would determine the response rate of the steam turbine, and as a result, an inflection point exists on the curve which describes the relationship between hydraulic servo-motor time constant and system damping. The result demonstrates that the characteristics of system damping can be used in parameter debugging of steam turbine.

Design of the Hydraulic System of Lead Plate Coiling Machine

2014 ◽  
Vol 937 ◽  
pp. 336-340
Author(s):  
Hui Sen ◽  
Rui Bo Yuan ◽  
Rong Li
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
Position Control ◽  
Torque Control ◽  
Tension Control ◽  
Hydraulic Motor ◽  
Relief Valve ◽  
Lead Plate ◽  
Hydraulic Servo ◽  
Close Loop Control

This paper mainly introduces the process of lead electrolysis, the structure and working principle of lead plate coiling machine and Its’ parts, coiling machine components. First of all, rewind section hydraulic system adopts a return to the oil throttle speed control, it is stable and can bear a certain change load, can overcome the stage before the tension fluctuation of the impaction to the rotation speed of hydraulic motor. Secondly, speed and tension control system adopt electro-hydraulic servo valve and proportional relief valve are respectively to the drum speed and output torque control,it has high precision and accurate in speed and tension control. contact coiling section use electro hydraulic servo position control system with close loop control to improve the accuracy of position control. Finally, calculate parameters of each working section of hydraulic control system , verify the hydraulic component model and the rationality of the hydraulic circuit.

scholarly journals Bricklaying Robot Lifting and Levelling System

2021 ◽  
Vol 23 (4) ◽  
pp. B257-B264
Author(s):  
Piotr Wos ◽  
Ryszard Dindorf ◽  
Jakub Takosoglu
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Design Process ◽  
Hydraulic System ◽  
Servo Drive ◽  
Synchronization Errors ◽  
Position Errors ◽  
Hydraulic Servo ◽  
The Mathematical Model ◽  
Servo Drive System

The article presents the concept of building and controlling a Bricklaying Robotic System (BRS). The research presents the design process and how to control a four-cylinder electro-hydraulic servo drive system. The article presents a mathematical model and optimizes the process of aligning the mobile support platform of the masonry robot. The lifting mechanism was presented and its kinematic analysis performed. The mathematical model of the hydraulic system was described. The control system, designed for the masonry robot lifting platform, includes position errors for a single drive axis and synchronization errors between the axes.

The Effects of Orifice Sizes on a Hydraulic Servo Valve Control System

2013 ◽  
Author(s):  
Marshall McNea ◽  
Shanzhong (Shawn) Duan
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
Pressure Pulse ◽  
Dynamical Behavior ◽  
Servo Valve ◽  
External Orifice ◽  
Hydraulic Servo ◽  
Hydraulic System Design ◽  
Valve Control ◽  
Orifice Size

Precision control for a force controlled hydraulic system can be achieved through the use of a flow controlled servo valve. Servo valves can be manufactured with a spool that is overlapped, an under lapped, or has a zero lap. A servo valve with a zero lap is desirable for a responsive hydraulic system without leakage, but has the disadvantage of creating a pressure pulse upon opening the valve. The hydraulic system for this setup involves having a double end, double action actuator that will have a cyclic motion generating multiple pressure waves in the system. Including an orifice in the system, which will function as a dampener, can reduce the pressure pulses. Traditional locations for orifices have been in the spool and on the actuator piston. For this hydraulic system design an external orifice will be introduced into the system via the use of an orifice plate included in the hydraulic fittings. This change allows for the ability to change the orifice size. Changing the orifice size to determine the effects on the systems control will be analyzed. The intended outcome is to demonstrate that different sized orifice plates will cause changes to the control system behavior so that an experimental formula will be established for this approach of a zero lap valve with an external damper for reduction of overshooting of dynamical behavior of the valve spool.

The Application of Servo Motor Direct Drive Pump Control System in Pre-Bending Machine

2014 ◽  
Vol 529 ◽  
pp. 544-548
Author(s):  
Huan Wang ◽  
Yi Min Xu
Keyword(s):  
Control System ◽  
Energy Saving ◽  
Hydraulic System ◽  
Closed Loop ◽  
Control Unit ◽  
Servo Motor ◽  
Direct Drive ◽  
Motor Speed ◽  
Reduce Energy Consumption ◽  
Drive Pump

Efficient and energy-saving are the development tendencies of the pre-bending machine. The new pre-bending machine is consisted of a constant pump driven by servo motor instead of common motor, variable pump and proportion valve. The advantage of this hydraulic system is energy-saving and it’s a closed-loop which controls the hydraulic system. In order to get different flow, it needs to adjust the servo motor speed by the control unit. This hydraulic system not only has a good performance, but also can significantly reduce energy consumption.

Research of New Servo-Hydraulic Press Based on the AC Servo Motor Control

2012 ◽  
Vol 522 ◽  
pp. 542-545 ◽  
Author(s):  
Lian Xia ◽  
Yang Xiao ◽  
Gui Shan Li ◽  
Hua Zhai ◽  
Jiang Han
Keyword(s):  
Motor Control ◽  
Control System ◽  
Hydraulic System ◽  
Hydraulic Press ◽  
Servo Motor ◽  
Electrical Control ◽  
Ac Servo ◽  
Hardware Component ◽  
Ac Servo Motor ◽  
Valve Control

Servo-hydraulic press is a kind of hydraulic press which has feedback device and can detect and feedback signals. Nowadays traditional servo-hydraulic press based on proportion-al servo valve control has been often used,but the study of this article is a new servo-hydraulic press based on the AC servo motor control. In this article, the hydraulic system of new servo-hydraulic press,and the electrical control system including the hardware component and software system have been mainly designed.

Composite adaptive control based on historical data for electro-hydraulic system driven by dual servo motor-pump with unknown disturbance

2021 ◽  
pp. 095965182199860
Author(s):  
Xiaofu Zhang ◽  
Guanglin Shi
Keyword(s):  
Adaptive Control ◽  
Hydraulic System ◽  
Historical Data ◽  
Tracking Performance ◽  
Load Force ◽  
Position Tracking ◽  
Servo Motor ◽  
Estimated Parameters ◽  
Unknown Disturbance ◽  
Composite Adaptive Control

This article presents a composite adaptive control method to improve the position-tracking performance of an electro-hydraulic system driven by dual constant displacement pump and dual servo motor named as a novel electro-hydraulic system with unknown disturbance. A composite adaptive controller based on backstepping method is designed to estimate the uncertainties of electro-hydraulic control system, including the damping coefficient and elastic modulus. In order to release the persistent excitation condition of conventional adaptive control, which is often infeasible in practice, a prediction error based on the online historical data is used to update the estimated parameters. Furthermore, a disturbance observer is used to estimate the disturbance including the unmeasurable load force, friction and other unmodeled disturbance. The experiment results are provided and compared with other methods to verify the effectiveness of the proposed method, and the results have indicated that the proposed method has a better position-tracking performance with the convergent estimated parameters.

A Hydraulic Control System Design for Change-Wheel Garage of Light Rail Based on PLC

2012 ◽  
Vol 233 ◽  
pp. 76-79
Author(s):  
Yong Gang Yang ◽  
Jun Sun ◽  
Meng Tao Yang
Keyword(s):  
Control System ◽  
System Design ◽  
Servo Control ◽  
Light Rail ◽  
Control System Design ◽  
Hydraulic Control ◽  
Plc Control ◽  
Servo Control System ◽  
Hydraulic Servo ◽  
Hydraulic Control System

This paper introduces the hydraulic control system design for the change-wheel garage of Chongqing light rails through analysis of three-stage cylinder synchronization circuit for lifting bodies, and optimizing the design of the slewing mechanism with respect to the hydraulic servo control system of digital cylinder. The results improved the smoothness in the process of changing wheel lifting and the rotary accuracy of the rotary mechanism. Design on the PLC control system of the system is also included as part of this paper.

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