Closed Loop Hydraulic System and Its Effect on Actuator Design

2021 ◽  
Author(s):  
Karan Sotoodeh
Keyword(s):  
Hydraulic System ◽  
Closed Loop ◽  
Actuator Design

Research into the Variable Speed Pump Control System for Driving the Cutter Head of Shield Tunneling Machine

2009 ◽  
Vol 628-629 ◽  
pp. 257-262 ◽  
Author(s):  
Tong Xing
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
Closed Loop ◽  
Control Method ◽  
Control Technique ◽  
Closed Loop Control ◽  
Variable Speed ◽  
Shield Tunneling ◽  
Loop Control ◽  
Cutter Head

The cutter head drive hydraulic system of φ1.8m simulate shield machine is introduced in this article, which has the variable speed pump control technique and the closed loop control method. The AMESim simulation model of the hydraulic system is built up, and the efficiency of the hydraulic system, speed control performance by open loop and closed loop control are analyzed. The result of the simulation shows that the variable speed pump control system has higher efficiency than the variable displacement pump control system about 4%-26% in the same condition when the cutter head speed is at the range of 0.5-4r/min, and the hydraulic system has good dynamic characteristics in closed-loop PID control.

A Control Algorithm for Active/Passive Hydraulic Winches Used in Active Heave Compensation

2019 ◽  
Author(s):  
Geir-Arne Moslått ◽  
Damiano Padovani ◽  
Michael R. Hansen
Keyword(s):  
Hydraulic System ◽  
Control Algorithm ◽  
Closed Loop ◽  
Peak Pressure ◽  
Control Method ◽  
High Fidelity Simulation ◽  
Speed Performance ◽  
Variable Displacement ◽  
Active Motor ◽  
Classical Control

Abstract The most common active heave compensated offshore cranes have hydraulic winch systems. This paper investigates an active/passive hydraulic winch system with variable-displacement motors and variable-displacement pumps. The paper addresses the challenges when the active motors are set with a low displacement. The active motor displacement is shown to have significant impact on the dynamics of the closed loop hydraulic system. The classical control strategy for this type of system do not address these challenges and will in certain situations have significantly reduced performance. Therefor, a new control method is presented that utilize the variable displacement of the pumps and motors for speed control and to improve dynamics characteristics. The new winch controller is tested in a high-fidelity simulation model and is shown to improve low speed performance, reduce winch speed limitations by up to 30%, reduce system peak pressure by approximately 20%, and reduce control error by approximately 30%.

Research on the Startup Control for the Closed-Circuit Hydraulic System Based on Expert Control Method

2007 ◽  
Author(s):  
Dongming Hu ◽  
Bing Xu ◽  
Huayong Yang
Keyword(s):  
Hydraulic System ◽  
Closed Loop ◽  
Control Method ◽  
Static Friction ◽  
Work Conditions ◽  
Friction Model ◽  
Closed Circuit ◽  
Expert Control ◽  
Working Principle ◽  
Startup Performance

The closed circuit hydraulic system is a typical nonlinear and time-varying system. In order to get excellent startup performance, the controller based on expert control method was designed. The theoretical and experimental research of the controller was carried out. Firstly, the working principle of the closed circuit hydraulic system was introduced. The difficulties of pressure pre-balanced control and closed-loop speed control for the system starting were indicated because of its friction, high-inertia and time delay. The influence of nonlinear friction on the startup performance of the system was analyzed. And the initial model of the friction was established through experiments. Then, the intelligent controller was designed basing on expert control method. The startup performance was evaluated by the integral of difference between the desired and the practical speed while the system ran. The static friction model and the parameters of the controller can be modified by the expert controller according to the last two results. Finally, experiments were carried out under different work conditions, namely variable loads and oil-temperatures. The results show that the startup performance of the system is excellent. The robustness of the expert controller is strong under different work conditions. That is, the proposed method is robust in the presence of nonlinearities and uncertainties.

Design and Efficiency Analysis of Closed Loop Pump Controlled Circuit Hydraulic Lifting System of Wheel Loaders Based on Gravity Self-Balancing Hydraulic Cylinder

2021 ◽  
Author(s):  
Xiangyu Wang ◽  
Hongjuan Zhang ◽  
Xiaogang Zhang ◽  
Long Quan
Keyword(s):  
Potential Energy ◽  
Hydraulic System ◽  
Closed Loop ◽  
Hydraulic Cylinder ◽  
Gravity Potential ◽  
Gravitational Potential Energy ◽  
Controlled Systems ◽  
Working Principle ◽  
Wheel Loaders ◽  
Lifting System

Abstract In the hydraulic lifting systems of wheel loaders, the valve controlled systems are used to drive the hydraulic cylinder to complete frequent lifting and falling operations. The gravitational potential energy of the lifting system, accumulated in the lifting process, is converted into heat energy through the throttling port of the valve during the falling processes, which results in significant throttling loss and severe system overheating. To solve the problems, a potential energy regeneration and utilization system is proposed, where the closed loop pump controlled circuit based on the gravity self-balancing hydraulic cylinder is adopted to eliminate throttling loss, and the gravity self-balancing chamber of the cylinder is directly connected with accumulator to recycle gravity potential energy. In the research, the structure and working principle of the proposed hydraulic system is analyzed first, then the co-simulation model and the test prototype are established to investigate the working and energy characteristics of the proposed system. Test results indicate that, compared with the traditional valve controlled hydraulic system, 58.9% energy consumption reduction can be expected for the hydraulic pump by adopting the proposed system under the same working condition.

Robust Suboptimal Control of an Electro-Hydraulic System with Variable Supply Pressure

2012 ◽  
Vol 215-216 ◽  
pp. 1283-1290
Author(s):  
Min Zhang ◽  
Jin Wang ◽  
Guo Bing Huang
Keyword(s):  
Hydraulic System ◽  
Closed Loop ◽  
Control Method ◽  
Performance Criterion ◽  
Suboptimal Control ◽  
Parameter Uncertainties ◽  
Genetic Search ◽  
Supply Pressure ◽  
Loop Transfer Function ◽  
Quadratic Performance

In this study, a robust H2 suboptimal control method is proposed for an electro-hydraulic system with variable supply pressure. The H2 suboptimal controller is designed to minimize the sum of a quadratic performance criterion and the H2 norm of the closed-loop transfer function from the white noise disturbance to the system state space variables. The genetic algorithm is used to select the weighting matrices of the quadratic performance criterion. In order to improve the robust performance, parameter uncertainties of the electro-hydraulic system are considered in the process of genetic search. Simulation results demonstrate the effectiveness of the proposed approach.

Design and Simulation of the Hydraulic Synchronous Control System of the Upper Roller in Bending Machine

2015 ◽  
Vol 713-715 ◽  
pp. 752-755
Author(s):  
Yang Cao ◽  
Kai Wen Qiu ◽  
Guo Qing Wu ◽  
Rong Chuan Yu ◽  
Chao Chao Zhong
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
Closed Loop ◽  
System Simulation ◽  
Open Loop ◽  
Closed Loop System ◽  
Synchronous Control ◽  
Pid Algorithm ◽  
Synchronous System ◽  
Hydraulic Cylinders

This paper sketches the overall structure of the hydraulic system of bending machine, and designs the hydraulic synchronous control system of the upper roller in bending machine. Then making use of AMEsim software to establish hydraulic system simulation model to analyze the pressure, velocity, displacement and other parameters of hydraulic cylinders in two cases when in open loop and closed loop system. After that, use PID algorithm to simulate the upper roller of bending machine in hydraulic closed loop synchronous system, which verifies that it can meet the motion requirements and get a higher synchronous precision.

Generic Design Methodology for Electro-Hydraulic Servo Actuator in Aero-Engine Main Fuel Control System

2014 ◽  
Author(s):  
Huawei Wang ◽  
Xi Wang ◽  
Wei Dang ◽  
Huating Yao ◽  
Bin Wang
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
Design Methodology ◽  
Closed Loop ◽  
Design Method ◽  
Control Valve ◽  
Open Loop ◽  
Duty Ratio ◽  
Aero Engine ◽  
Servo Actuator

Focusing on the problem that the high stable quality and excellent servo performance of electrohydraulic actuator are needed in aero-engine control system, this paper aims to propose a complete design method for electrohydraulic servo actuator. Firstly, the static characteristics of mechanical-hydraulic system including solenoid control valve, slave valve and metering valve was analyzed to identify their main structure parameters. Secondly, a nonlinear model of this open-loop mechanical-hydraulic system was established in the framework of AMESim. Thirdly, the model’s transfer function was obtained through Prediction Error Methods (PEM) in system identification. Based on the above work, given that the saturation of duty ratio is a nonlinear link, an integral-separated PI controller was applied to constitute the closed-loop electrohydraulic servo actuator. Moreover, to get optimal performance, the controller parameters design was transferred into an optimization process using Differential Evolution (DE) algorithm. Simulation results illustrated that the designed closed-loop electrohydraulic servo actuator shows rapid servo tracking performance, small overshoot and low power loss. It is consistent with the actual engineering and can be used in most aero-engines. In addition, the entire design methodology is generic and can be transplanted in other actuators design.

scholarly journals Algorithm for designing of speed change control devices through a gear differential with a closed-loop hydraulic system

2021 ◽  
Vol 1 (101) ◽  
pp. 138-148
Author(s):  
Oleh Strilets ◽  
Volodymyr Malashchenko ◽  
Viacheslav Pasika
Keyword(s):  
Hydraulic System ◽  
Closed Loop ◽  
Ring Gear ◽  
Hydraulic Systems ◽  
Practical Application ◽  
Single Row ◽  
Rotational Movement ◽  
Speed Change ◽  
Control Devices ◽  
Gear Differential

The algorithm of practical application of researches results of speed changes management devices with a gear differential and the stopper of rotational movement in the form of the closed-loop hydraulic system has been described. An example is a single-stage single-row gear differential, when the driving link is a sun gear, driven is a ring gear, and the control link is a carrier. For such a device, the order of execution of in design steps has been described. The described execution procedure of speed change devices designing will be valid for all kinematic schemes of single- and multistage gear differentials with stoppers of rotational movement in the form of the closed-loop hydraulic systems with control through carriers.

LNG Tank Dome Air Raising Technology Research Based on Closed-Loop Tension Control

2014 ◽  
Vol 511-512 ◽  
pp. 569-572
Author(s):  
Wen Da Zhu ◽  
Jie Jiang ◽  
Gong Sheng Yang ◽  
Nan Jin Gao ◽  
Jing Peng Yan ◽  
...  
Keyword(s):  
Hydraulic System ◽  
Closed Loop ◽  
Control Device ◽  
Wire Rope ◽  
Tension Control ◽  
Control Technology ◽  
Technology Research ◽  
Efficient Energy ◽  
Lng Tank ◽  
Installation Technology

LNG gains popularity as a kind of clean and efficient energy, LNG tank dome air raising installation technology is a key problem for tank construction, chain preloaded is adopted in traditional balance guidance device, the wire rope tension cant maintain a constant in air raising, which brings great safety hidden trouble. In this paper, the tension control technology based on closed-loop was put forward, the tension control device was designed and the hydraulic system principle was designed. Tensioning force can be adjusted automatically in the air raising process by researching on LNG dome air raising technology based on closed-loop tension control. It is of great significance for improving the efficiency and safety in the process of air raising .

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