Load-Force-Adaptive Outlet Throttling: An Easily Commissionable Independent Metering Control Strategy

2016 ◽  
Author(s):  
Jan Lübbert ◽  
André Sitte ◽  
Benjamin Beck ◽  
Jürgen Weber
Keyword(s):  
Hydraulic System ◽  
Control Algorithm ◽  
Systematic Approach ◽  
Load Force ◽  
Chamber Pressure ◽  
The Novel ◽  
Test Rig ◽  
Mechanical Pressure ◽  
And Control ◽  
Inlet Chamber

This paper deals with a novel independent metering valve system which is intended to be used in medium sized mobile machines. The system uses a mechanical pressure compensator to enable a very simple SISO control algorithm which does not need any feedback parameters to be adjusted. The algorithm is capable of handling resistive and pulling loads at a certain desired velocity and inlet chamber pressure level. The paper gives a brief summary of the systematic approach to deriving the valves structure and compares different control approaches for the complete hydraulic system comprising several actuators. Special emphasis is given to the preferred solution, which is verified on a laboratory test rig consisting of reasonably priced mobile machine components. Furthermore a linear model of system and control structure is constructed to give detailed information regarding the dynamic characteristics of the controlled drive. The energetic benefits of the novel system architecture in comparison to a standard coupled metering flow sharing system are investigated by means of a levelling movement performed on the test rig and a simulated synthetic high power digging cycle.

An Energy-Saving Way to Balance Variable Negative Load Based on Back-Stepping Control With Load Observer

2016 ◽  
Author(s):  
Jin Mengren ◽  
Wang Qingfeng
Keyword(s):  
Energy Saving ◽  
Hydraulic System ◽  
Control Algorithm ◽  
Chamber Pressure ◽  
Extra Energy ◽  
Power Machinery ◽  
Back Stepping Control ◽  
And Control ◽  
Balance Variable ◽  
Inlet Chamber

Traditionally, counterbalance valve (CBV) is widely used to counterbalance negative load of fluid power machinery. CBV introduces extra energy consumption and oscillation to hydraulic system especially for time varying system. The essence of its shortcoming is the inflexibility of the control architecture. In this article, a proportional orifice is adopted to counterbalance negative load, which makes the control strategy flexible. A load observer is proposed to demonstrate the load dynamically. A control algorithm based on back-stepping design is proposed in this paper afterwards, aiming at keeping the inlet chamber pressure of the actuator around a fairy small value. The control error is estimated, as well. A simulation for the process of the excavator booming down is carried out to verify the observer and control algorithm, which proves the energy-saving target achieved.

A new type of hydraulic cylinder system controlled by the new-type hydraulic transformer

2013 ◽  
Vol 228 (12) ◽  
pp. 2233-2245 ◽  
Author(s):  
Wei Shen ◽  
Jihai Jiang ◽  
Xiaoyu Su ◽  
Hamid Reza Karimi
Keyword(s):  
Hydraulic System ◽  
Control Algorithm ◽  
Basic Structure ◽  
Hydraulic Cylinder ◽  
Control Methods ◽  
Test Rig ◽  
Hydraulic Transformer ◽  
Simulation Languages ◽  
New Type ◽  
Made In

In order to enhance the efficiency of the hydraulic system, one new-type hydraulic transformer is presented in this paper. First, the basic structure and the principle of the new-type hydraulic transformer are explained. Then, the mathematical models including both the inner and outer loops are analyzed. Moreover, two kinds of control methods are discussed corresponding to the two loops, respectively. Furthermore, the proposed strategies are translated into the simulation languages, and the simulation is made in Simulink. Finally, the prototypes of new-type hydraulic transformer and the test rig are constructed to test the performance. Both the simulated and experimental results show that the new-type hydraulic transformer can be used in the practical condition, and the proposed control algorithm is suitable.

A Study of Simulation of Hydropreumatic Suspension Experiment Rig Based on AMESim and Matlab/Simulink

2014 ◽  
Vol 599-601 ◽  
pp. 207-211
Author(s):  
Zhi Qiang Chao ◽  
Chu Ming Ning ◽  
Hua Ying Li
Keyword(s):  
Pid Control ◽  
Hydraulic System ◽  
Control Algorithm ◽  
Scientific Basis ◽  
Servo Control ◽  
Fuzzy Pid Control ◽  
Servo Control System ◽  
Hydraulic Servo ◽  
Excellent Control ◽  
And Control

By analyzing the mechanical and control module of electro-hydraulic servo control system of hydropreumatic suspension experiment rig, and finding the corresponding mathematical model, and constructing a controller with fuzzy PID control algorithm, and then using AMESim with the accurate modeling of the hydraulic system and Simulink with powerful data analysis and processing functions for system to simulate to verify the experiment rig excellent control performance, which can effectively provide a scientific basis for the optimization of vehicle safety and comfort.

Residual Gas Reaction in the Electron Microscope: II The Design of a Gas-Control Chamber for Quantitative Observations

1969 ◽  
Vol 27 ◽  
pp. 82-83
Author(s):  
Chester J. Calbick ◽  
Richard E. Hartman
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Local Environment ◽  
Chamber Pressure ◽  
Objective Lens ◽  
Ion Pump ◽  
Quantitative Studies ◽  
Precise Knowledge ◽  
Differential Pumping ◽  
And Control

Quantitative studies of the phenomenon associated with reactions induced by the electron beam between specimens and gases present in the electron microscope require precise knowledge and control of the local environment experienced by the portion of the specimen in the electron beam. Because of outgassing phenomena, the environment at the irradiated portion of the specimen is very different from that in any place where gas pressures and compositions can be measured. We have found that differential pumping of the specimen chamber by a 4" Orb-Ion pump, following roughing by a zeolite sorption pump, can produce a specimen-chamber pressure 100- to 1000-fold less than that in the region below the objective lens.

scholarly journals Multi-Objective Optimization of Integrated Civilian-Military Scheduling of Medical Supplies for Epidemic Prevention and Control

Healthcare ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 126
Author(s):  
Hai-Feng Ling ◽  
Zheng-Lian Su ◽  
Xun-Lin Jiang ◽  
Yu-Jun Zheng
Keyword(s):  
Prevention And Control ◽  
Large Scale ◽  
Medical Services ◽  
The Novel ◽  
Multi Objective ◽  
Medical Supplies ◽  
Problem Instances ◽  
Novel Coronavirus ◽  
And Control ◽  
Minimum Ratio

In a large-scale epidemic, such as the novel coronavirus pneumonia (COVID-19), there is huge demand for a variety of medical supplies, such as medical masks, ventilators, and sickbeds. Resources from civilian medical services are often not sufficient for fully satisfying all of these demands. Resources from military medical services, which are normally reserved for military use, can be an effective supplement to these demands. In this paper, we formulate a problem of integrated civilian-military scheduling of medical supplies for epidemic prevention and control, the aim of which is to simultaneously maximize the overall satisfaction rate of the medical supplies and minimize the total scheduling cost, while keeping a minimum ratio of medical supplies reservation for military use. We propose a multi-objective water wave optimization (WWO) algorithm in order to efficiently solve this problem. Computational results on a set of problem instances constructed based on real COVID-19 data demonstrate the effectiveness of the proposed method.

A Mathematical Model Including Mechanical Structure, Hydraulic and Control of LHDS

Robotica ◽  
2021 ◽  
pp. 1-16
Author(s):  
Guoliang Ma ◽  
Kaixian Ba ◽  
Zhiwu Han ◽  
Zhengguo Jin ◽  
Bin Yu ◽  
...  
Keyword(s):  
Simulation Model ◽  
Hydraulic System ◽  
Inverse Dynamics ◽  
Hydraulic Drive ◽  
Operation Time ◽  
Variable Load ◽  
Mechanical Structure ◽  
Load Characteristics ◽  
Common Problems ◽  
And Control

SUMMARY In this paper, mathematical models of kinematics, statics and inverse dynamics are derived firstly according to the mechanical structure of leg hydraulic drive system (LHDS). Then, all the above models are integrated with MATLAB/Simulink to build the LHDS simulation model, the model not only considers influence of leg dynamic characteristics on hydraulic system but also takes into account nonlinearity, variable load characteristics and other common problems brought by hydraulic system, and solves compatibility and operation time which brought by using multiple software simultaneously. The experimental results show the simulation model built in this paper can accurately express characteristics of the system.

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.

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