A Novel Pneumatic Non-Contact Suction Pad With Embedded Air Bearings

2010 ◽  
Author(s):  
Jyh-Chyang Renn ◽  
Chin-Yi Cheng
Keyword(s):  
Closed Loop ◽  
Cfd Simulation ◽  
Control Valve ◽  
Proper Function ◽  
Work Piece ◽  
Air Bearings ◽  
Directional Control ◽  
Gap Control ◽  
Application Fields ◽  
Directional Control Valve

In this paper, a novel suction pad based on CFD simulation and vortex levitation principle is proposed. To assure the absolute non-contact between the suction pad and the work-piece, four symmetrical air bearings are introduced and integrated into the design of the suction pad. In addition, the closed-loop gap control is applied to the operation of the suction pad, which avoids successfully the possible initial impact and maintains the desired gap between the suction pad and the work-piece. The vortex inside the suction pad serves to levitate the work-piece and the air bearings, on the contrary, try to push the work-piece away if the work-piece comes too close to the suction pad. Therefore, a proper function switching between the vortex and the air bearings is necessary. In this paper, a 5/3 pneumatic proportional directional control valve is utilized to switch these functions mentioned above. In the future, such a suction pad may find some potential application fields, like the pick-up and transportation devices for TFT-LCD, solar energy panels, etc.

scholarly journals DYNAMICS OF PROPORTIONAL SPEED CONTROL VERSUS SERVO SPEED CONTROL OF A HOSE / CABLE SPOOLING DEVICE FOR WINCH

2020 ◽  
Vol 61 (2) ◽  
pp. 350-359
Author(s):  
Alexandru-Polifron Chirita ◽  
Marian Blejan ◽  
Teodor-Costinel Popescu ◽  
Ana-Maria Popescu
Keyword(s):  
Closed Loop ◽  
Dynamic Performance ◽  
Control Valve ◽  
Speed Control ◽  
Hydraulic Cylinder ◽  
Directional Control ◽  
First Case ◽  
Control Versus ◽  
And Control ◽  
Directional Control Valve

This article presents and analyses in two cases the dynamic performance of regulation and control of the linear speed of an electro-hydraulically driven mechatronic axis. In the first case, the flow control is performed with a proportional hydraulic directional control valve, while in the second case the control is performed with a servo-valve. The linear mechatronic axis is part of a complex subsystem used in both agriculture and industry, that allows the precise winding of a hose / cable on a drum with the help of a spooling device, which conditions the positioning of the hose. The speed control of the hydraulic cylinder with bilateral rod on whose liner the spooling device is fixed is performed in a closed loop with the help of transducers and a programmable controller (PLC).

DYNAMICS OF PROPORTIONAL SPEED CONTROL VERSUS SERVO SPEED CONTROL OF A HOSE / CABLE SPOOLING DEVICE FOR DRUM

2020 ◽  
pp. 379-388
Author(s):  
Alexandru-Polifron Chirita ◽  
Marian Blejan ◽  
Teodor-Costinel Popescu ◽  
Ana-Maria Popescu
Keyword(s):  
Closed Loop ◽  
Dynamic Performance ◽  
Control Valve ◽  
Speed Control ◽  
Hydraulic Cylinder ◽  
Directional Control ◽  
First Case ◽  
Control Versus ◽  
And Control ◽  
Directional Control Valve

This article presents and analyses in two cases the dynamic performance of regulation and control of the linear speed of an electro-hydraulically driven mechatronic axis. In the first case, the flow control is performed with a proportional hydraulic directional control valve, while in the second case the control is performed with a servo-valve. The linear mechatronic axis is part of a complex subsystem used in both agriculture and industry that allows the precise winding of a hose / cable on a drum with the help of a spooling device, which conditions the positioning of the hose. The speed control of the hydraulic cylinder with bilateral rod on whose liner the spooling device is fixed is performed in a closed loop with the help of transducers and a programmable controller (PLC).

scholarly journals CFD Simulation of a Post-Compensated Load Sensing Directional Control Valve

2021 ◽  
Vol 312 ◽  
pp. 05002
Author(s):  
Paola Fresia ◽  
Massimo Rundo
Keyword(s):  
Pressure Drop ◽  
Cfd Simulation ◽  
Control Valve ◽  
Design Tool ◽  
Lumped Parameter Model ◽  
Cfd Model ◽  
Load Sensing ◽  
Directional Control ◽  
Lumped Parameter ◽  
Directional Control Valve

The paper presents the CFD model of a load sensing directional control valve. The model was validated experimentally in terms of pressure drop and flow force at different positions of the spool. The spool position was imposed manually by means of a micrometric screw and a load cell was used for measuring the flow force. The CFD model was developed with the CAD-embedded tool FloEFD®. The model has been proved to be very reliable in estimating the pressure drop, moreover quite good results were obtained also in the evaluation of the flow force. The CFD simulations were used to tune the coefficients of a lumped parameter model of the valve, so that such a model can be efficiently used for the simulation of an entire hydraulic circuit. Moreover, the CFD model has been used as design tool for attenuating the detrimental effect of the flow force. In particular, the width of the land upstream of the metering edge has an influence on the resultant force on the spool. If was found that it is possible to significantly reduce the flow force at maximum opening with a relatively small increment of the pressure drop across the valve.

Study on Static and Dynamic Characteristics of Load-Sensing and Pressure-Compensated Directional Control Valve

2013 ◽  
Vol 753-755 ◽  
pp. 2693-2699 ◽  
Author(s):  
Rui Lin Feng ◽  
Jian Hua Wei ◽  
Jin Hui Fang
Keyword(s):  
Transfer Function ◽  
Working Conditions ◽  
Dynamic Characteristics ◽  
Pressure Coefficient ◽  
Control Valve ◽  
Parameters Optimization ◽  
Static And Dynamic Characteristics ◽  
Load Sensing ◽  
Directional Control ◽  
Directional Control Valve

This study presents the static and dynamic characteristics of load-sensing and pressure-compensated directional control valve under the working conditions. A mathematical model is developed, two types of working conditions are presented through the static work point calculation. The static characteristic is analyzed by simulation, and the conclusion is validated by experiments. Solution procedure of the flow gain transfer function and flow-pressure coefficient transfer function is detailed introduced based on the above static computation, and their dynamic characteristic is analyzed by using Bode diagram. Finally, three types of compensatory modes are proposed, which provides very useful value and significance for the hydraulic component or system design and parameters optimization.

scholarly journals Transient Phenomena Caused by Directional Control Valve in a Hydraulic Pipeline

1973 ◽  
Vol 16 (102) ◽  
pp. 1911-1917 ◽  
Author(s):  
Koji TAKAHASHI ◽  
Shigeru IKEO ◽  
Yoneaki TAKAHASHI
Keyword(s):  
Control Valve ◽  
Transient Phenomena ◽  
Directional Control ◽  
Directional Control Valve

Positioning control of hydraulic cylinder with unknown friction using on/off directional control valve

2018 ◽  
Vol 232 (8) ◽  
pp. 983-993 ◽  
Author(s):  
Liyang Jin ◽  
Qingfeng Wang
Keyword(s):  
Predictive Models ◽  
Control Valve ◽  
Hydraulic Cylinder ◽  
Switching Frequency ◽  
Control Input ◽  
Positioning Control ◽  
Switching Law ◽  
Directional Control ◽  
Control Scheme ◽  
Directional Control Valve

In this study, a prediction-based positioning control scheme is proposed for the hydraulic cylinder controlled by a solenoid operated on/off directional control valve. The discrete-valued input, low switching frequency and significant delay of directional control valve make the control problem very complex. Only a discrete-valued control input can be used here; meanwhile, the input has switching frequency constraint and time-delay. Existing methods such as pulse-width modulation control and sliding-mode control are not suitable for this problem, because chattering may arise due to the control input restrictions. The newly proposed prediction-based positioning control scheme consists of two parts: a switching law based on predictions of future states and learning algorithms which learn required predictive models online. According to accurate predictions, the switching law can control the hydraulic cylinder to target position in an optimal way, and chattering is avoided. Meanwhile, the required predictive models are identified by a generalized growing and pruning for radial basis function network and a recursive least square estimation algorithm in real time. Essentially, the problems caused by input restrictions, time-delay and model uncertainty are solved by the accurate identifications to some well-designed models. The control scheme is verified by physical experiments. Fast and accurate positioning control can be achieved for the hydraulic cylinder with unknown nonlinear friction.

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