Second Paper: An Investigation into the Mechanism of the Frictional Damping of Machine Tool Slideways

1969 ◽  
Vol 184 (1) ◽  
pp. 1088-1096 ◽  
Author(s):  
R. Bell ◽  
M. Burdekin
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Machine Tool ◽  
Instantaneous Velocity ◽  
Feed Drive ◽  
Feed Drives ◽  
Frictional Damping ◽  
Major Emphasis

The damping action of a plain slideway is considerably influenced by a number of parameters and is difficult to assess. It has been necessary, therefore, to obtain experimental data from adequately scaled experiments. The major emphasis is placed on the influence of polar additive lubricants as they offer considerable advantages in stabilizing feed drives at low feed speeds. This paper describes an investigation into the mechanism of the interaction between vibration in the direction of motion and the vibration normal to the plane of the slideway interface. Steady-state characteristics do not give an adequate guide to the damping action of a machine tool slideway. All the work discussed in this paper is restricted to vibration amplitudes that do not cause the instantaneous velocity of the feed drive to be reversed.

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.

Researches Regarding the Use of Fuzzy Controllers within CNC Feed Drives

2015 ◽  
Vol 772 ◽  
pp. 229-234
Author(s):  
Radu Eugen Breaz ◽  
Octavian Bologa
Keyword(s):  
Machine Tool ◽  
Fuzzy Controller ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Fuzzy Controllers ◽  
Feed Drive ◽  
Feed Drives ◽  
Simulation Based ◽  
Position Controller ◽  
Dc Servomotor

This paper presents some simulation based upon a dynamic model of a feed-drive within the structure of a CNC machine tool. A DC servomotor was considered as actuation device for the feed drive. For a given set of parameters for the position controller, two fuzzy types of fuzzy controllers were tested by means of simulation. The first fuzzy controller was a proportional one, with one input and one output, while the second one was a two variables one, with two inputs and one outputp.

Influence of Machine Tool Covers on Feed Drives

2011 ◽  
Author(s):  
Petr Kolar ◽  
Jan Masek ◽  
Jiri Sveda ◽  
Jan Hudec
Keyword(s):  
Machine Tool ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Reaction Force ◽  
Point Of View ◽  
Feed Drive ◽  
Feed Drives ◽  
Maximum Reaction ◽  
Stiffness And Damping ◽  
Multi Body

Machine tool covers are important parts of the machine. From the point of view of feed drives, a cover is an additional multi-body system that influences the dynamic properties of the feed drive and the positioning accuracy of the machine. The advantages of covers connected to the machine table with flexible elements are shown on simulation and experimental results. A mathematical model of the cover and its connection to the machine table is described. Optimization of the stiffness and damping ratio for the connection, using a model of the cover, is suggested. The optimal connection parameters cause decreasing of maximum reaction force acting from the cover to the feed drive. This phenomenon is presented on simulation example and also on the experiment results.

Model of a CNC Feed Drive for On-Site Tuning of the Controllers for Single Axis Motion

2016 ◽  
Vol 841 ◽  
pp. 133-138
Author(s):  
Radu Eugen Breaz ◽  
Sever Gabriel Racz ◽  
Octavian Bologa ◽  
Melania Tera
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Cnc Machine Tools ◽  
Simulation Tool ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Feed Drive ◽  
Feed Drives ◽  
Contouring Accuracy ◽  
High Degree

The accuracy of CNC machine-tools is heavily influenced by the correct tuning of the feed drives controllers. While an initial tuning is performed by the machine-tool manufactures, in time the values have to be changed by the user in order to preserve positioning and contouring accuracy of the machine. This paper presents a model of a CNC feed drive, for a particular CNC machine-tool, but with a high degree of generality. The objective is to provide the user the necessary knowledge, together with a simple, yet accurate simulation tool, in order to assist him in the process of tuning the controllers.

Kinetic analysis of mechanism of intestinal Na+-dependent sugar transport

1985 ◽  
Vol 248 (5) ◽  
pp. C498-C509 ◽  
Author(s):  
D. Restrepo ◽  
G. A. Kimmich
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Sugar Transport ◽  
Enzyme Kinetic ◽  
Steady State Distribution ◽  
State Distribution ◽  
Least Squares Fit ◽  
Coupling Stoichiometry ◽  
Rate Limiting ◽  
Kinetics Of

Zero-trans kinetics of Na+-sugar cotransport were investigated. Sugar influx was measured at various sodium and sugar concentrations in K+-loaded cells treated with rotenone and valinomycin. Sugar influx follows Michaelis-Menten kinetics as a function of sugar concentration but not as a function of Na+ concentration. Nine models with 1:1 or 2:1 sodium:sugar stoichiometry were considered. The flux equations for these models were solved assuming steady-state distribution of carrier forms and that translocation across the membrane is rate limiting. Classical enzyme kinetic methods and a least-squares fit of flux equations to the experimental data were used to assess the fit of the different models. Four models can be discarded on this basis. Of the remaining models, we discard two on the basis of the trans sodium dependence and the coupling stoichiometry [G. A. Kimmich and J. Randles, Am. J. Physiol. 247 (Cell Physiol. 16): C74-C82, 1984]. The remaining models are terter ordered mechanisms with sodium debinding first at the trans side. If transfer across the membrane is rate limiting, the binding order can be determined to be sodium:sugar:sodium.

Electron drift caused by rf field gradient creates many plasma phenomena: An attempt to distinguish the cause and the effect

2011 ◽  
Vol 78 (2) ◽  
pp. 165-174 ◽  
Author(s):  
C. L. XAPLANTERIS ◽  
E. D. FILIPPAKI ◽  
I. S. MISTAKIDIS ◽  
L. C. XAPLANTERIS
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Low Temperature ◽  
Mathematical Models ◽  
Field Gradient ◽  
Collision Frequency ◽  
The Other ◽  
Frequency Effect ◽  
Electron Drift ◽  
Plasma Parameters

AbstractMany experimental data along with their theoretical interpretations on the rf low-temperature cylindrical plasma have been issued until today. Our Laboratory has contributed to that research by publishing results and interpretative mathematical models. With the present paper, two issues are being examined; firstly, the estimation of electron drift caused by the rf field gradient, which is the initial reason for the plasma behaviour, and secondly, many new experimental results, especially the electron-neutral collision frequency effect on the other plasma parameters and quantities. Up till now, only the plasma steady state was taken into consideration when a theoretical elaboration was carried out, regardless of the cause and the effect. This indicates the plasma's complicated and chaotic configuration and the need to simplify the problem. In the present work, a classification about the causality of the phenomena is attempted; the rf field gradient electron drift is proved to be the initial cause.

Detection Limit of Large Area Id Thin Film Position Sensitive Detectors Based in a-Si:H P.I.N. Diodes

1995 ◽  
Vol 377 ◽  
Author(s):  
R. Martins ◽  
G. Lavareda ◽  
F. Soares ◽  
E. Fortunato
Keyword(s):  
Thin Film ◽  
Experimental Data ◽  
Steady State ◽  
Detection Limit ◽  
Large Area ◽  
Position Sensitive ◽  
Position Sensitive Detectors

ABSTRACTThe aim of this work is to provide the basis for the interpretation of the steady state lateral photoeffect observed in p-i-n a-Si:H ID Thin Film Position Sensitive Detectors (ID TFPSD). The experimental data recorded in ID TFPSD devices with different performances are compared with the predicted curves and the obtained correlation's discussed.

High-Precision Tracking Control of Machine Tool Feed Drives Based on ADRC

2016 ◽  
Author(s):  
Chengyong Zhang ◽  
Yaolong Chen
Keyword(s):  
Machine Tool ◽  
High Precision ◽  
Tracking Control ◽  
Position Control ◽  
Feedback System ◽  
Pi Controller ◽  
Ball Screw ◽  
Feed Drives ◽  
Precision Tracking ◽  
Precision Tracking Control

In this paper, the active-disturbance-rejection control (ADRC) is applied to realize the high-precision tracking control of CNC machine tool feed drives. First, according to the number of the feedback channel, the feed systems are divided into two types: signal-feedback system, e.g., linear motor and rotary table, and double-feedback system, e.g., ball screw feed drive with a load/table position feedback. Then, the appropriate controller is designed to ensure the closed-loop control performance of each type of system based on the idea of ADRC. In these control frameworks, the extended state observers (ESO) estimate and compensate for unmodeled dynamics, parameter perturbations, variable cutting load, and other uncertainties. For the signal-feedback system, the modified ADRC with an acceleration feedforward term is used directly to regulate the load/table position response. However, for the double-feedback system, the ADRC is applied only to the motor position control, and a simple PI controller is used to achieve the accurate position control of the load. In addition, based on ADRC feedback linearization, a novel equivalent-error-model based feedforward controller is designed to further improve the command following performance of the double-feedback system. The experimental results demonstrate that the proposed controllers of both systems have better tracking performance and robustness against the external disturbance compared with the conventional P-PI controller.

Vorschubantrieb für unstetige Bewegungsprofile*/Feed Drive for Discontinuous Profiles. Concept for motion generation in feed drives using an inertia-based momentum actuator

2018 ◽  
Vol 108 (05) ◽  
pp. 295-300
Author(s):  
P. Zahn ◽  
A. Lechler ◽  
A. Verl
Keyword(s):  
Dynamic Behavior ◽  
Experimental Verification ◽  
Multibody Simulation ◽  
Motion Generation ◽  
Feed Drive ◽  
Feed Drives ◽  
Contour Deviation

Das dynamische Verhalten von Vorschubantrieben hat wesentlichen Einfluss auf Qualität und Produktivität. Dabei sind konstante Bahngeschwindigkeit und eine möglichst kleine Abweichung der Bahn an Satzübergängen konträre Zielgrößen. Dieser Beitrag beschreibt ein neuartiges Antriebskonzept mit einem Zusatzaktor, welcher durch Impulseintrag das Verhalten einer Vorschubachse für unstetige Sollwertprofile verbessern kann. Anhand einer Mehrkörpersimulation wird das Prinzip demonstriert und beispielhaft experimentell verifiziert.   The dynamic behavior of feed drives is strongly influencing quality and productivity. However, a constant path velocity and a small contour deviation are contrary design targets. This paper shows a novel drive concept using an additional actuator. By introducing an additional momentum, the behavior of the feed drives can be improved for discontinuous path profiles. Based on a multibody simulation, this principle is presented followed by an experimental verification.

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