scholarly journals Stable Switching Control Strategy of the Support Pressure and Velocity of Shield Machine Gripper Shoes

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Nannan Liu ◽  
Jishen Peng ◽  
Liye Song ◽  
Pinhe Wang ◽  
Kun Zhang
Keyword(s):  
Position Control ◽  
Control Method ◽  
Control Strategies ◽  
Pressure Control ◽  
Surrounding Rock ◽  
Support Pressure ◽  
Hydraulic Pressure ◽  
Compound Control ◽  
Hydraulic Servo ◽  
Shield Machine

An electro-hydraulic servo position and pressure compound control method was investigated considering the working principle of a hydraulic stepping motor of a shield machine gripper shoe and its practical working characteristics in the supporting process. The control targets were to improve the support efficiency and reduce the disturbance of gripper shoes on the surrounding rock. In this method, a fuzzy switching controller was used to switch between electro-hydraulic position control and electro-hydraulic pressure control. Numerical and prototype simulation experiments were conducted on the control method. The theoretical analysis and experimental results showed that the control method could effectively convert the gripper shoes from an unsupported state to a supported state in a short amount of time, as well as realize surge-free switching between position control and pressure control. Thus, disturbance of the gripper shoes on the surrounding rock could be reduced. The results of this study provide a theoretical basis for research on control strategies of hydraulic stepping propulsion of shield machines.

Hydraulic Pressure Control System Simulation and Performance Test of Lower Extremity Exoskeleton

2012 ◽  
Vol 472-475 ◽  
pp. 2548-2553 ◽  
Author(s):  
Xing Xing Li ◽  
Qing Guo ◽  
Lu Lu Zhang ◽  
Hong Zhou ◽  
Xiang Gang Zhang
Keyword(s):  
Control System ◽  
Lower Extremity ◽  
Performance Test ◽  
Position Control ◽  
Control Method ◽  
Pressure Control ◽  
Frequency Domain Method ◽  
Hydraulic Pressure ◽  
Pressure Control System ◽  
And Performance

On basis of the introduction for the composition of carried-load assistance system and the control mechanism of hydraulic pressure valve for lower extremity exoskeleton, the position control loop is built. The control system is designed by frequency domain method using the PID parameters combined with lead correction network. Simulation results show that the control method can servo the angle of knee joint as human’s natural walk as well as the harmonious of man-machine moment. According to performance test of hydraulic pressure control system, the flow and pressure in piston is analyzed considering different load, the pressure of oil box and movable mode. Test results show that hydraulic pressure valve control system can realize efficiently slow walk carried 30 kilogram load, up and down stairs.

Depth Control of an Electro-Hydraulic Servo System Based on Fractional Order PID

2012 ◽  
Vol 430-432 ◽  
pp. 1650-1654
Author(s):  
Qiang Gao ◽  
Li Jun Ji ◽  
Run Min Hou ◽  
Ji Lin Chen
Keyword(s):  
Control Method ◽  
Control Strategies ◽  
Industrial Applications ◽  
Control Performance ◽  
Tracking Accuracy ◽  
Servo Systems ◽  
Performance Indexes ◽  
Hydraulic Servo ◽  
Excellent Control ◽  
Fractional Order Pid

Electro-hydraulic servo systems (EHSS) are widely used in many industrial applications, and to determine the control strategies to exhibit high robustness and high precision remains the focus of attention. In order to improve the control performance of EHSS, a novel control method, based on fractional PID (FPID) controller, is proposed and designed for the EHSS. The transfer function of EHSS is constructed using first-principle method. The feasibility and availability of the proposed controller are examined by numerical simulation. The control performances of fractional FPID are well assessed based on performance indexes, including response time, tracking accuracy and robustness. The results of the simulation verify that FPID controller is of excellent control performance, and is suitable for the control of EHSS.

Study and Development on an Electro-Hydraulic Pressure Control System of the Riveting Machine

2013 ◽  
Vol 321-324 ◽  
pp. 1641-1644 ◽  
Author(s):  
Li Xu
Keyword(s):  
Control System ◽  
Control Parameter ◽  
Pressure Control ◽  
Fast Response ◽  
Hydraulic Pressure ◽  
Precise Control ◽  
Control Precision ◽  
Pressure Control System ◽  
Hydraulic Servo ◽  
High Control

An electro-hydraulic servo pressure control system was proposed, which meet the request of fast response, zero overstep and high control precision, based on analyzing the technique of riveting. The proper control parameter which is got by the debugging result of the PID arithmetic in PLC realized the precise control of systems pressure. In practice the device has good application value.

scholarly journals Relevance of hydraulic modelling in planning and operating real-time pressure control: case of Oppegård municipality

2017 ◽  
Vol 20 (3) ◽  
pp. 535-550 ◽  
Author(s):  
Luigi Berardi ◽  
Antonietta Simone ◽  
Daniele B. Laucelli ◽  
Rita M. Ugarelli ◽  
Orazio Giustolisi
Keyword(s):  
Real Time ◽  
Information And Communication Technologies ◽  
Water Distribution ◽  
Control Strategies ◽  
Pressure Control ◽  
Distribution Networks ◽  
Support Pressure ◽  
Real Time Control ◽  
The Real ◽  
Time Operation

Abstract Technical best practices recommend pressure control as an effective countermeasure to reduce leakages in water distribution networks (WDNs). Information and communication technologies allow driving pressure reducing valves (PRVs) in real-time based on pressure observed at remote control nodes (remote real-time control – RRTC), going beyond the limitations of classic PRV control (i.e. with target pressure node just downstream of the device). Nowadays, advanced hydraulic models are able to simulate both RRTC-PRVs and classic PRVs accounting for unreported and background leakages as diffused pressure-dependent outflows along pipes. This paper studies how such models are relevant to support pressure control strategies at both planning and operation stages on the real WDN of Oppegård (Norway). The advanced hydraulic model permits demonstration that RRTC-PRVs in place of existing classic PRVs might reduce unreported and background leakages by up to 40%. The same analysis unveils that advanced models provide reliable evaluation of leakage reduction efforts, overcoming the inconsistencies of lumped indexes like the Infrastructure Leakage Index (ILI). Thereafter, the model allows comparison of three strategies for the real-time electric regulation of PRVs in some of the planned scenarios, thus supporting real-time operation of RRTC-PRVs.

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.

Experimental Based Analysis of the Pressure Control Characteristics of an Oil Hydraulic Three-Way On/Off Solenoid Valve Controlled by PWM Signal

2001 ◽  
Vol 124 (1) ◽  
pp. 196-205 ◽  
Author(s):  
Heon-Sul Jeong ◽  
Hyoung-Eui Kim
Keyword(s):  
Position Control ◽  
Pressure Control ◽  
Solenoid Valve ◽  
Design Parameters ◽  
Duty Ratio ◽  
Hydraulic Pressure ◽  
Mean Pressure ◽  
Ripple Amplitude ◽  
The Mean ◽  
Driving Signal

Pressure control characteristics of a three-way high-speed on/off oil hydraulic solenoid valve driven by a PWM signal with a fixed pulse period were theoretically and experimentally analyzed and evaluated. By virtue of its relatively low cost, small size, robustness to contamination, and simplicity of the driving circuit, the three-way on/off solenoid valve is increasingly and widely used for hydraulic pressure or position control applications. In this paper, two formulas are newly derived for the mean and the ripple amplitude of the system pressure that oscillates with the same frequency as that of the PWM driving signal. The formulas indicate that the mean pressure and the pressure ripple amplitude depend on three major system variables that are the on- and the off-times of the valve and a parameter, the system configuration coefficient a, that characterizes the overall feature of the system. The mean pressure and the ripple are then shown to depend on both the duty ratio and the carrier frequency of the PWM driving signal, which disproves Tanaka’s claim that a single variable is enough to describe two quantities. Several aspects of the formulas are discussed. The accuracy of the new formulas is verified by comparing the calculation results to corresponding experimental test results. A method is proposed to obtain the system parameters of the opening and closing-case delay times, the time constants of the valve and a. The selection criteria are established for the major design parameters of the driving signal, i.e., the duty ratio and the carrier pulse frequency, and a basic strategy is proposed on how to suppress the undesirable ripple for a hydraulic servo control system using three-way on/off solenoid valve.

Auto-calibration Based Control and Its Application to a Kind of Electrohydraulic Poppet Valves

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Patrick Opdenbosch ◽  
Nader Sadegh ◽  
Wayne Book
Keyword(s):  
Control Algorithm ◽  
Control Method ◽  
Pressure Control ◽  
The State ◽  
Input State ◽  
Hydraulic Pressure ◽  
The Novel ◽  
Supply Pressure ◽  
State Trajectory ◽  
Transition Map

This paper describes a novel learning/adaptive state trajectory control method and its application to electronic hydraulic pressure control. The control algorithm presented herein learns the inverse input-state mapping of the plant at the same time this map is employed in the feedforward loop to force the state of the plant to asymptotically converge to a prescribed state trajectory. The algorithm accomplishes this task without requiring prior exact information about the state transition map of the plant. The novel controller is applied to an electrohydraulic poppet valve with the objective of tracking a desired supply pressure signal. In this application, the controller learns the inverse conductance characteristics of the valve. The supply pressure tracking performance subject to the proposed controller is validated through experimental data.

scholarly journals A Method of Two-Stage Pressure Control Based on Multistage Orifices

2021 ◽  
Vol 11 (2) ◽  
pp. 589
Author(s):  
Junxia Gao ◽  
Fenghe Wu ◽  
Jun Tang ◽  
Zichun Geng
Keyword(s):  
Control Method ◽  
Pressure Control ◽  
Hydraulic Pressure ◽  
Complex Flow ◽  
Two Stage ◽  
Scheme Design ◽  
Electrical Failure ◽  
Fluid Systems ◽  
Multiple Actuators ◽  
And Control

The interaction of pressure and flow in a hydraulic system with multiple working conditions, multiple actuators, and large flow limits action adjustment and control. Through a pilot pressure control circuit, hydraulically operated valves can adjust pressure or direction more effectively. A recent study proposed a two-stage pressure control method based on multistage orifices and solenoid valves. The requirements of the number and diameter ratio of short orifices in the series to realize the two-stage pressure control were theoretically analyzed. Scheme design and experiment were carried out. The influence of structures of complex flow channel and solenoid valve on the higher or lower pilot control pressure was considered in the experiment. The method was experimentally verified and successfully applied in a turbine electrohydraulic control system with lower maintenance costs, making the system more reliable in the case of electrical failure. Research results provide insight into pilot pressure control in fluid systems using multistage orifices to achieve either higher or lower pressure. In addition, it has important guiding significance for the design of valves or engineering systems based on pilot hydraulic pressure.

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