Comparison Precision of Oil Film Thickness of a Hydrostatic Bearing by Using Different Controllers under External Load

2013 ◽  
Vol 415 ◽  
pp. 192-195
Author(s):  
Ming Chang Shih ◽  
Jen Sheng Shie
Keyword(s):  
Film Thickness ◽  
Fuzzy Controller ◽  
Sliding Mode ◽  
Dead Zone ◽  
Displacement Sensor ◽  
Practical Implementation ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Hydraulic Servo ◽  
Self Tuning

This paper describes a hydrostatic bearing to maintain the oil film thickness, which integrates the hydraulic servo control technology. This study has designed the different intelligent nonlinear controllers by using a non-contact displacement sensor to feedback the oil film thickness of the bearing. This study proposes a fuzzy controller, a self-tuning fuzzy controller and a self-tuning fuzzy sliding mode mechanism to modify the output scaling factor and adds a dead zone compensator to achieve a constant oil film thickness. Finally, the experimental results are used to verify the feasibility and practical implementation success of this study.

Studying Systems of Stabilization of Supports in Hydrostatic Machine Tool

2012 ◽  
Vol 622-623 ◽  
pp. 489-493
Author(s):  
Iskander Beisembetov ◽  
Sabyi Ussupov ◽  
Bakhyt Absadykov ◽  
Beken Arymbekov ◽  
Birzhan Bektibay
Keyword(s):  
Film Thickness ◽  
Machine Tools ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Operational Parameters ◽  
Automatic Stabilization ◽  
Design Elements ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Automatic Control Systems

Development relevance to improve the operational parameters of the support units of machine tools in their design elements is introduced that increase the rigidity of the components, their carrying capacity, damp occurring vibrations in the process, the coefficient of performance (COP), smoothness of motion, positioning accuracy, reducing the wear of their working surfaces and maintain the original accuracy. A number of engineering development [1], [2], aimed at improving the above characteristics of the machine by changing and improving design of reference nodes used in these rails rolling bearings, aerostatic and hydrostatic guides, as well as the use of automatic control systems of its basic parameters, determine its quality. However, in some operating conditions in which errors occur, mainly due to the instability of oil-film thickness (gap) between the mobile and immobile elements of the hydrostatic bearing. For high accuracy requirements it will negatively affect the quality of machined parts and equipment performance. On this basis, it becomes apparent urgency of the problem of automatic stabilization of oil-film thickness (gap) in the IR. To ensure high precision equipment to improve power system hydrostatic bearing units of machine tools. This, in turn, creates the prerequisite for the development of stabilization systems of the gap in the hydrostatic bearing, with the help of which the thickness of oil layer in them would be kept constant even with significant dynamic load on the support.

Chaotic Gyros Synchronization

2011 ◽  
pp. 183-209
Author(s):  
M. Roopaei ◽  
M. J. Zolghadri ◽  
B. S. Ranjbar ◽  
S. H. Mousavi ◽  
H. Adloo ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Control Method ◽  
Fuzzy Controller ◽  
Sliding Mode ◽  
Dead Zone ◽  
Control Input ◽  
Mode Control ◽  
Fuzzy Sliding Mode ◽  
Robust Adaptive ◽  
Fuzzy Parameter

In this chapter, three methods for synchronizing of two chaotic gyros in the presence of uncertainties, external disturbances and dead-zone nonlinearity are studied. In the first method, there is dead-zone nonlinearity in the control input, which limits the performance of accurate control methods. The effects of this nonlinearity will be attenuated using a fuzzy parameter approximator integrated with sliding mode control method. In order to overcome the synchronization problem for a class of unknown nonlinear chaotic gyros a robust adaptive fuzzy sliding mode control scheme is proposed in the second method. In the last method, two different gyro systems have been considered and a fuzzy controller is proposed to eliminate chattering phenomena during the reaching phase of sliding mode control. Simulation results are also provided to illustrate the effectiveness of the proposed methods.

Application of dynamic mesh technology in the oil film flow simulation for hydrostatic bearing

2019 ◽  
Vol 71 (1) ◽  
pp. 146-153
Author(s):  
Yanqin Zhang ◽  
Zhiquan Zhang ◽  
Xiangbin Kong ◽  
Rui Li ◽  
Hui Jiang
Keyword(s):  
Film Thickness ◽  
Flow Velocity ◽  
Manufacturing Industry ◽  
Dynamic Mesh ◽  
Lubricating Oil ◽  
Thickness Variation ◽  
Content Type ◽  
Oil Film ◽  
Rotating Speed ◽  
Hydrostatic Bearing

Purpose The purpose of this paper was to obtain the lubrication characteristics of heavy hydrostatic bearing in heavy equipment manufacturing industry through theoretical analysis and numerical simulation. Design/methodology/approach This paper discusses the influence of oil film thickness variation on velocity field, outlet-L and outlet-R flow velocity under the hydrostatic bearing running in no-load 0 N, load 400 KN, full load 1,500 KN and rotating speeds of 10 r/min, 20 r/min, 30 r/min, 40 r/min, 50 r/min and 60 r/min, by using dynamic mesh technology and FLUENT software. Findings When the working table rotates clockwise, in the change process of oil film thickness, the fluid flow pattern of the lubricating oil at the edge of the sealing oil is the rule of laminar flow, and the oil cavity has a vortex. The outlet-R flow velocity becomes higher and higher by increasing the bearing load and working table speed, and the flow velocity increases with the decrease in oil film thickness; the outlet-L flow velocity increases with the decrease in oil film thickness under low rotating speed (less than 10 r/min) condition and decreases with the decrease of oil film thickness under high rotating speed (more than 60 r/min) condition. Originality/value The influence of the oil film thickness on the flow state distribution of the oil film was analyzed under different working conditions, and the influence rules of oil film thickness on the flow velocity of hydrostatic bearing oil pad was obtained by using dynamic mesh technology.

Study of Fluid-Solid Simulation on the Large-Scale Hydrostatic Bearing of Hollow Coaxial

2009 ◽  
Vol 628-629 ◽  
pp. 281-286 ◽  
Author(s):  
Xiang Jun Yu ◽  
Ji Xin Wang ◽  
Yong Li
Keyword(s):  
Film Thickness ◽  
Large Scale ◽  
Maximum Stress ◽  
Impact Factors ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Simulation Results ◽  
Stress And Deformation

In order to investigate the changing law of the film thickness caused by the deformation of hollow coaxial and drum-shaped lining and accurately calculate the stress of hollow coaxial and rum-shaped lining, the fluid-solid numerical simulatied model of a large-scale hydrostatic bearing was established. The stress and deformation of hollow coaxial and drum-shaped lining was obtained by indirect coupled methods. The typical impact factors and the deformation laws of the thinnest film were discussed. The simulation results indicate that the maximum stress locatioes on the drum-shaped lining and hollow coaxial; and the deformation of the hollow coaxial is 60.47 times that of the drum-shaped lining, and the oil film thinnest thickness decreases by 12.1% due to the deformation of the hollow coaxial and drum-shaped lining; and the stiffness of the hollow coaxial makes greatest impact on oil film deformation.

An ultrasonic measurement method for full range of oil film thickness

2018 ◽  
Vol 233 (3) ◽  
pp. 481-489 ◽  
Author(s):  
Kai Zhang ◽  
Pan Dou ◽  
Tonghai Wu ◽  
Kai Feng ◽  
Youquan Zhu
Keyword(s):  
Reflection Coefficient ◽  
Film Thickness ◽  
Measurement Method ◽  
Ultrasonic Method ◽  
Dead Zone ◽  
Full Range ◽  
Thickness Measurement ◽  
Ultrasonic Measurement ◽  
Center Frequency ◽  
Oil Film

Ultrasonic method is quite promising for oil film thickness measurement in industry, while there is normally a dead zone for one ultrasonic sensor with a special center frequency when measuring the oil film thickness by the traditional reflection coefficient amplitude. In this paper, an ultrasonic measurement method for full range of oil film thickness was investigated. The theoretical relationship between the oil film thickness and the reflection coefficient phase was firstly built up and the reflection coefficient phase was found to be able to measure the oil film thickness in the dead zone. Then the reflection coefficient amplitude and phase were combined to measure the oil film thickness in the full range. A high-precision calibrated rig, which could form a series of known film thicknesses oil layers, was set up and the performance of this method was shown to work well. This method is significant for online oil film thickness monitoring in industry.

FORCE AND POSITION CONTROL OF THE PNEUMATIC CYLINDERS THROUGH A MICROSCOPE WITH A CCD CAMERA

2013 ◽  
Vol 37 (3) ◽  
pp. 571-580
Author(s):  
Chen Hung I ◽  
Shih Ming Chang
Keyword(s):  
Position Control ◽  
Fuzzy Controller ◽  
Dead Zone ◽  
Ccd Camera ◽  
Visual Servo ◽  
Control Interface ◽  
Manipulation System ◽  
Force Control System ◽  
Self Tuning ◽  
Pneumatic Cylinders

In this paper, the pneumatic driven manipulation system is driven by the pneumatic cylinders. The proposed system is built by the designed pneumatic force control system and the microscope, which are integrated with the control interface. Visual C++ code from MFC is used to finish the control interface. A self tuning fuzzy controller with a dead zone compensator is designed to improve the force precision of the proposed system. From experimental results, the force error can be controlled within ±1 mN and the position error can be stayed within ±1 pixel using the visual servo.

Hardware-in-Loop Simulation on Hydrostatic Journal Support Pose

2010 ◽  
Vol 44-47 ◽  
pp. 697-701
Author(s):  
Gui Hua Han ◽  
Ya Ping Wang ◽  
Yan Chun Zhong ◽  
Jun Peng Shao ◽  
Xiao Dong Yu ◽  
...  
Keyword(s):  
Film Thickness ◽  
Simulation Experiment ◽  
Control Variable ◽  
Hydraulic Cylinder ◽  
Oil Film ◽  
Hydraulic Servo ◽  
Pose Control ◽  
Hardware In Loop ◽  
Hardware In Loop Simulation ◽  
And Control

A scheme of improving performance of hydrostatic journal support was presented, that is, control journal support pose by controlling flow of four controllable chambers and Coupling various oil film thickness, to assure journal support expected pose; Chamber flow can be regulated by electro hydraulic servo valve-control variable pump according to the surface roughness, load, cutting force, and thermal results of journal support. The mathematical model of the controllable chambers flow, servo variable mechanism and controller were built; the pose control model was established, which contain the kinematics positive and negative solution and control strategy of hydraulic cylinder position feedback; Hardware-in-loop simulation experiment was carried on the electro hydraulic servo test bench by mean of the non-linear relation of film thickness and the hydraulic cylinder displacement. Simulation and Hardware-in-loop simulation experiment results show that the controllable journal support exhibit high oil film rigidity can stably and quickly track the expected goal and can be broadly applied in high precision heavy horizontal machine tool.

Sign in / Sign up

Export Citation Format

Share Document