Modeling friction effects in lubricated roller guideways using a modified LuGre model

2021 ◽  
pp. 107754632110139
Author(s):  
Parivash Soleimanian ◽  
Hamid Ahmadian
Keyword(s):  
Control System ◽  
Machine Tool ◽  
Dynamic Behavior ◽  
Frictional Contact ◽  
Position Control ◽  
Experimental Studies ◽  
Contact Interface ◽  
Lugre Model ◽  
Tool Positioning ◽  
And Performance

Guideways accommodate tool or workpiece translations, and their dynamic behavior and associated sliding effects have great impact on the precision, stability, and performance of the machine tool. During machining, guideway rollers experience oscillatory excitations because of cutting forces, which necessitate considering their pre-sliding behavior along with the sliding characteristics to compensate for the associated tracking errors using the position control system. This study considers friction effects in pre-sliding and sliding regimes of lubricated linear roller guideway systems to provide an accurate dynamic model of the machine tool element. To model the dynamic characteristics of frictional contact in the lubricated linear roller guideway, the LuGre model, commonly used in the machine tool positioning control system to estimate the compensating drive force, is modified considering the roller-raceway contact physics and the lubricant film dynamics. The proposed model also includes coupling effects between normal and tangential forces in the contact interface. Experimental studies were performed on a lubricated linear roller guideway to verify the performance of the presented modified LuGre model. In the experimental observations, the dynamic behavior of friction in the lubricated linear guideway is well illustrated. A comparison of the experimentally measured data and proposed modified LuGre model predictions shows the model can accurately predict dynamic behaviors of the frictional contact interface.

Control of bearingless electric machines dedicated for aviation

2020 ◽  
Vol 92 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Mariusz Żokowski ◽  
Krzysztof Falkowski ◽  
Paulina Kurnyta-Mazurek ◽  
Maciej Henzel
Keyword(s):  
Control System ◽  
Electric Motor ◽  
Position Control ◽  
Experimental Studies ◽  
Electric Machines ◽  
Magnetic Suspension ◽  
Content Type ◽  
Actuation System ◽  
Bearingless Motor ◽  
Rotary Speed

Purpose The paper presents the results of work on control systems of bearingless electric motors. Authors proposed the applications of bearingless electric machines for aircraft actuation system. Suggested solution characterizes novel concept of on-board equipment design such as More Electric Aircraft. Magnetic suspension technology allows elimination of friction force and the negative performance features of classic bearing system. However, to achieve all these purposes appropriately, dedicated control system must be also applied. Design/methodology/approach The development of a control system of bearingless electric machine is presented in detail. Mathematical model and construction of induction bearingless motor are widely discussed. Then, proportional–integral-derivative controller algorithm designing for BEM control system was presented using the well pole placement method. Simulation model of BEM control system with use of Matlab-Simulink software was shown. Finally, experimental studies on laboratory stand were introduced. The paper presents design methodology of conventional and advanced control system of bearingless motor. Findings The presented concept of the bearingless electric machines could be applied in the on-board actuation system. During research, full control system of bearingless electric motor was designed and tested. This system consisted of two subsystems. The first responded for rotary speed stabilization and second one was designed for position control of the rotor in the air gap. Practical implications The presented concept of the bearingless electric machines could be applied in the on-board actuation system. During research, full control system of bearingless electric motor was designed and tested. This system consisted of two subsystems. The first responded for rotary speed stabilization and second one was designed for position control of the rotor in the air gap. Originality/value The idea of active magnetic suspension system will be implemented for aviation on technology readiness level V. The paper presents unique laboratory stand with bearingless electric motor and experimental studies. The stable time responses of designed control system were presented and discussed. In addition, preliminary considerations of advanced control system with robust controller were introduced as well.

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.

Test and performance evaluation of the Gemini secondary mirror chopper and position control system

1998 ◽  
Author(s):  
Kenneth R. Lorell ◽  
Jean-Noel Aubrun ◽  
Ernesto O. Perez ◽  
Paul J. Reshatoff, Jr. ◽  
Donald F. Zacharie
Keyword(s):  
Performance Evaluation ◽  
Control System ◽  
Position Control ◽  
Secondary Mirror ◽  
And Performance ◽  
Position Control System

Dynamic Modeling and Controller Design for a Piezoelectric Actuation System Used for Machine Tool Control

1999 ◽  
Author(s):  
Paul Mayhan ◽  
K. Srinivasan ◽  
Sarawoot Watechagit ◽  
G. Washington
Keyword(s):  
Control System ◽  
Machine Tool ◽  
Dynamic Model ◽  
Position Control ◽  
Model Parameters ◽  
Piezoelectric Actuation ◽  
Nonlinear Dynamic Model ◽  
Low Frequencies ◽  
Actuation System ◽  
Position Control System

Abstract The dynamic model of a commercially available piezoelectric actuation system intended for use in a machine tool position control system is presented, and its fidelity to observed behavior evaluated. The components of the actuation system are presented and an available nonlinear dynamic model form for piezoelectric actuators, capable of representing actuator hysteresis, used as the basis for the system dynamic model. Parameters in the dynamic model are obtained from manufacturer’s specifications. The resulting actuator model is combined with a nonlinear model of the amplifier, the resulting system model forming the basis of a SIMULINK simulation. System responses based on the simulation are compared with experimentally measured responses. The agreement between simulation and experimental responses is reasonably good at low frequencies, and the model is used for preliminary closed loop position control system evaluations. Specific recommendations for improvement in model accuracy are also made.

АКУСТИЧНА ПОМІТНІСТЬ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ З СИЛОВИМИ УСТАНОВКАМИ НА БАЗІ ПОРШНЕВИХ ДВИГУНІВ

2020 ◽  
pp. 62-80
Author(s):  
В. В. Руденко ◽  
И. В. Калужинов ◽  
Н. А. Андрущенко
Keyword(s):  
Control System ◽  
Internal Combustion Engine ◽  
Power Plants ◽  
Combustion Engine ◽  
Spectral Characteristics ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Detection Range ◽  
Acoustic Signature ◽  
Static Conditions

The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75<2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.

AN APPROACH TO IMPROVE THE PERFORMANCE OF A POSITION CONTROL DC MOTOR BY USING DIGITAL CONTROL SYSTEM

2016 ◽  
Vol 11 (1) ◽  
pp. 21-33
Author(s):  
Debargha Chakraborty ◽  
Binanda Kishore Mondal ◽  
Souvik Chatterjee ◽  
Sudipta Ghosh
Keyword(s):  
Control System ◽  
Digital Control ◽  
Position Control ◽  
Dc Motor ◽  
Digital Control System

Improvement of horizontal borer control system

2020 ◽  
Vol 2020 (7) ◽  
pp. 41-48
Author(s):  
Dmitriy Petreshin ◽  
Viktor Khandozhko ◽  
Andrey Dubov ◽  
German Dobrovolsky
Keyword(s):  
Control System ◽  
Machine Tool ◽  
Feed Drive ◽  
Feed Drives ◽  
System Improvement

The control system improvement of a machine-tool is considered. The necessity in control system updating is substantiated. There is shown a procedure for horizontal borer updating. A problem on adjustment of modern digital electrical feed drives is presented. A sample of electrical feed drive and NC device adjustment is presented.

Robust Two-degree-of-freedom Control Based on H∞ Method for PMSM Drive System

2020 ◽  
Vol 13 (4) ◽  
pp. 496-506
Author(s):  
Qixin Zhu ◽  
Lei Xiong ◽  
Hongli Liu ◽  
Yonghong Zhu ◽  
Guoping Zhang
Keyword(s):  
Control System ◽  
Control Theory ◽  
Position Control ◽  
Dynamic Performance ◽  
Servo System ◽  
Degree Of Freedom ◽  
Trade Off ◽  
Standard Design ◽  
Position Controller ◽  
Two Degree Of Freedom

Background: The conventional method using one-degree-of-freedom (1DOF) controller for Permanent Magnet Synchronous Motor (PMSM) servo system has the trade-off problem between the dynamic performance and the robustness. Methods: In this paper, by using H∞ control theory, a novel robust two-degree-of-freedom (2DOF) controller has been proposed to improve the position control performance of PMSM servo system. Using robust control theory and 2DOF control theory, a H∞ robust position controller has been designed and discussed in detail. Results: The trade-off problem between the dynamic performance and robustness which exists in one-degree-of-freedom (1DOF) control can be dealt with by the application of 2DOF control theory. Then, through H∞ control theory, the design of robust position controller can be translated to H∞ robust standard design problem. Moreover, the control system with robust controller has been proved to be stable. Conclusion: Further simulation results demonstrate that compared with the conventional PID control, the designed control system has better robustness and attenuation to the disturbance of load impact.

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