Stick-Slip Compensation of Micro-Positioning Using Elastic-Plastic Static Friction Model

2008 ◽  
Vol 47-50 ◽  
pp. 246-249
Author(s):  
Min Gyu Jang ◽  
Chul Hee Lee ◽  
Seung Bok Choi
Keyword(s):  
Static Friction ◽  
Friction Model ◽  
Smart Structure ◽  
Asperity Contact ◽  
Stick Slip ◽  
Elastic Plastic ◽  
Highly Nonlinear ◽  
Bridge Type ◽  
Structural Parts ◽  
Rough Surface Contact

In this paper, a stick-slip compensation for the micro-positioning is presented using the statistical rough surface contact model. As for the micro-positioning structure, PZT (lead(Pb) zirconia(Zr) Titanate(Ti)) actuator is used to drive the load for precise positioning with its high resolution incorporating with the PID (Proportional Integral Derivative) control algorithm. Since the stick-slip characteristics for the micro structures are highly nonlinear and complicated, it is necessary to incorporate more detailed stick-slip model for the applications involving the high precision motion control. Thus, the elastic-plastic static friction model is used for the stick-slip compensation considering the elastic-plastic asperity contact in the rough surfaces statistically. Mathematical model of the system for the positioning apparatus was derived from the dynamic behaviors of structural parts. Since the conventional piezoelectric actuator generates the short stroke, a bridge-type flexural hinge mechanism is introduced to amplify the linear motion range. Using the proposed smart structure, simulations under the representative positioning motion were conducted to demonstrate the micro-positioning under the stick-slip friction.

Precision Motion Control of a Smart Structure Using an Enhanced Stick-Slip Model

2008 ◽  
Vol 56 ◽  
pp. 98-103 ◽  
Author(s):  
Min Gyu Jang ◽  
Chul Hee Lee ◽  
Seung Bok Choi
Keyword(s):  
Position Control ◽  
Static Friction ◽  
Smart Structure ◽  
Slip Model ◽  
Stick Slip ◽  
Precise Position ◽  
Positioning Device ◽  
Bridge Type ◽  
Rough Surface Contact ◽  
Precision Motion

In this paper, a smart structure for the micro position control is proposed using the piezo stack actuator. The smart structure is comprised with PZT based stack actuator, mechanical displacement amplifier and positioning devices. Based on the bridge-type flexural hinge mechanism, a displacement amplifier is designed and integrated with a piezo stack actuator to produce a desirable positioning stroke of the device. In order to achieve the high precision control performance in a positioning device, a stick-slip phenomenon should be suppressed in contacting surfaces of the device, which is generally indispensable in the mechanically connected systems and particularly obvious for the micro-scale system. Therefore, the stick-slip model is enhanced by theoretically calculating the static friction based on the statistical rough surface contact model. Then, a PID feedback control algorithm with the developed stick-slip model is formulated for achieving accurate positioning of the device. Using the proposed smart structure, simulations of precise position control under the representative operating condition of positioning are conducted to demonstrate the stick-slip suppressing and micro positioning performance.

Nanoscale Friction Dynamic Modeling

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Fakhreddine Landolsi ◽  
Fathi H. Ghorbel ◽  
Jun Lou ◽  
Hao Lu ◽  
Yuekai Sun
Keyword(s):  
Friction Model ◽  
Experimental Results ◽  
Atomic Scale ◽  
Model Parameters ◽  
Large Set ◽  
Asperity Contact ◽  
State Variables ◽  
Stick Slip ◽  
Proposed Model ◽  
Nanoscale Friction

Friction and system models are fundamentally coupled. In fact, the success of models in predicting experimental results depends highly on the modeling of friction. This is true at the atomic scale where the nanoscale friction depends on a large set of parameters. This paper presents a novel nanoscale friction model based on the bristle interpretation of single asperity contact. This interpretation is adopted after a review of dynamic friction models representing stick-slip motion in macrotribology literature. The proposed model uses state variables and introduces a generalized bristle deflection. Jumping mechanisms are implemented in order to take into account the instantaneous jumps observed during 2D stick-slip phenomena. The model is dynamic and Lipchitz, which makes it suitable for future control implementation. Friction force microscope scans of a muscovite mica sample were conducted in order to determine numerical values of the different model parameters. The simulated and experimental results are then compared in order to show the efficacy of the proposed model.

An AFM-Based Nanomanipulation Model Describing the Atomic Two Dimensional Stick-Slip Behavior

2007 ◽  
Author(s):  
Fakhreddine Landolsi ◽  
Fathi H. Ghorbel ◽  
James B. Dabney
Keyword(s):  
Friction Model ◽  
Modular Approach ◽  
Dynamic Friction ◽  
Asperity Contact ◽  
Two Dimensional ◽  
Stick Slip ◽  
Complex Interactions ◽  
Proposed Model ◽  
Lattice Periodicity ◽  
Afm Cantilever

A new AFM-based nanomanipulation model describing the relevant physics and dynamics at the nanoscale is presented. The nanomanipulation scheme consists of integrated subsystems that are identified in a modular approach. The model subsystems define the AFM cantilever-sample dynamics, the AFM tip-sample interactions, the contact mechanics and the friction between the sample and the substrate. The coupling between these different subsystems is emphasized. The main contribution of the proposed nanomanipulation model is the use of a new 2D dynamic friction model based on a generalized bristle interpretation of one asperity contact. The efficacy of the proposed model to reproduce experimental data is demonstrated via numerical simulations. In fact, the model is shown to describe the 2D stick-slip behavior with the substrate lattice periodicity. The proposed nanomanipulation model facilitates the improvement and extension of each subsystem to further take into account the complex interactions at the nanoscale.

Friction compensation control of an electropneumatic servovalve by using an evolutionary algorithm

2000 ◽  
Vol 214 (3) ◽  
pp. 173-184 ◽  
Author(s):  
S H Choi ◽  
C O Lee ◽  
H S Cho
Keyword(s):  
Search Algorithm ◽  
Static Friction ◽  
Open Loop ◽  
Friction Model ◽  
Experimental Results ◽  
Friction Compensation ◽  
Stick Slip ◽  
Air Contamination ◽  
Compensation Control ◽  
Friction Models

A poppet-type electropneumatic servovalve developed in this study utilizes a poppet directly operated by a moving-coil actuator in the metering stage and is controlled by a digital controller. This servovalve is insensitive to air contamination and has no problem of air leakage at null, but it has relatively large friction between the O-rings installed in the peripheral grooves of the balance pistons and the valve sleeve. For friction compensation control, a static friction model that enables simulation of the stick-slip phenomena and a dynamic model that captures the friction behaviour such as presliding displacement and varying break-away force are presented. The parameters for the friction models are identified by utilizing an evolution strategy, one of the evolutionary algorithms, which is a probabilistic global search algorithm based on the model of natural evolution. These friction models are then used in designing a non-linear friction compensation controller. It is found in the experiment that the electropneumatic servovalve has almost no hysteresis and that the friction compensation control significantly improves valve performance. The experimental results of the open loop test on poppet positioning agree well with simulation results of the valve model with identified friction parameters. It is also shown that the experimental results of friction compensation control using a static friction model show a small steady state error but those using a dynamic friction model show almost no such error.

Experimental Verification of an Improved Elastic-Plastic Static Friction Model Including Roughness Effects

2005 ◽  
Author(s):  
Chul-Hee Lee ◽  
Andreas A. Polycarpou
Keyword(s):  
Surface Roughness ◽  
Wear Debris ◽  
Static Friction ◽  
Force Transducer ◽  
Friction Model ◽  
Experimental Measurements ◽  
Roughness Effects ◽  
Experimental Conditions ◽  
Interface Motion ◽  
Elastic Plastic

An experimental study was performed to measure the static friction coefficient under different experimental conditions. These include different surface roughness conditions, the effect of dwell time, the effect of acceleration (sliding velocity) as well as the presence of traces of lubricant and wear debris at the interface. The static friction tester provides accurate measurement of friction, normal and lateral forces at the interface (using a high dynamic bandwidth piezoelectric force transducer) as well as precise motion control and measurement of the interface motion. The experimental measurements were subsequently compared with an improved elastic-plastic rough surface static friction model, and it was found that the model captures the experimental measurements well, especially in terms of surface roughness. However, the data also shows the limitations of the model as it fails to accurately capture the effects of experimental conditions such as the presence of wear debris and start up velocity.

Analysis of Friction-Induced Limit Cycling in an Experimental Drill-String System

2004 ◽  
Vol 126 (4) ◽  
pp. 709-720 ◽  
Author(s):  
N. Mihajlovic´ ◽  
A. A. van Veggel ◽  
N. van de Wouw ◽  
H. Nijmeijer
Keyword(s):  
Steady State ◽  
Oil And Gas ◽  
Static Friction ◽  
Friction Model ◽  
Drill String ◽  
Torsional Vibrations ◽  
State Behavior ◽  
Rotary Drilling ◽  
Stick Slip ◽  
Predictive Quality

In this paper, we aim for an improved understanding of the causes for torsional vibrations that appear in rotary drilling systems used for the exploration of oil and gas. For this purpose, an experimental drill-string setup is considered. In that system, torsional vibrations with and without stick-slip are observed in steady state. In order to obtain a predictive model, a discontinuous static friction model is proposed. The steady-state behavior of the drill-string system is analyzed both numerically and experimentally. A comparison of numerical and experimental bifurcation diagrams indicates the predictive quality of the model. Moreover, specific friction model characteristics can be linked to the existence of torsional vibrations with and without stick-slip.

scholarly journals A Review of Elastic–Plastic Contact Mechanics

2017 ◽  
Vol 69 (6) ◽  
Author(s):  
Hamid Ghaednia ◽  
Xianzhang Wang ◽  
Swarna Saha ◽  
Yang Xu ◽  
Aman Sharma ◽  
...  
Keyword(s):  
State Of The Art ◽  
Asperity Contact ◽  
Elastic Plastic ◽  
Single Asperity ◽  
Current State ◽  
Metallic Contacts ◽  
Contact Models ◽  
Rough Surface Contact ◽  
Elastic And Plastic Deformation ◽  
Very High

In typical metallic contacts, stresses are very high and result in yielding of the material. Therefore, the study of contacts which include simultaneous elastic and plastic deformation is of critical importance. This work reviews the current state-of-the-art in the modeling of single asperity elastic–plastic contact and, in some instances, makes comparisons to original findings of the authors. Several different geometries are considered, including cylindrical, spherical, sinusoidal or wavy, and axisymmetric sinusoidal. As evidenced by the reviewed literature, it is clear that the average pressure during heavily loaded elastic–plastic contact is not governed by the conventional hardness to yield strength ratio of approximately three, but rather varies according to the boundary conditions and deformed geometry. For spherical contact, the differences between flattening and indentation contacts are also reviewed. In addition, this paper summarizes work on tangentially loaded contacts up to the initiation of sliding. As discussed briefly, the single asperity contact models can be incorporated into existing rough surface contact model frameworks. Depending on the size of a contact, the material properties can also effectively change, and this topic is introduced as well. In the concluding discussion, an argument is made for the value of studying hardening and other failure mechanisms, such as fracture as well as the influence of adhesion on elastic–plastic contact.

A Static Friction Model for Elastic-Plastic Contacting Rough Surfaces

2004 ◽  
Vol 126 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Lior Kogut ◽  
Izhak Etsion
Keyword(s):  
Friction Coefficient ◽  
Rough Surfaces ◽  
Static Friction ◽  
Friction Model ◽  
Plasticity Index ◽  
High Plasticity ◽  
Elastic Plastic ◽  
Static Friction Coefficient ◽  
Contact Adhesion ◽  
Limiting Case

A model that predicts the static friction for elastic-plastic contact of rough surfaces is presented. The model incorporates the results of accurate finite element analyses for the elastic-plastic contact, adhesion and sliding inception of a single asperity in a statistical representation of surface roughness. The model shows strong effect of the external force and nominal contact area on the static friction coefficient in contrast to the classical laws of friction. It also shows that the main dimensionless parameters affecting the static friction coefficient are the plasticity index and adhesion parameter. The effect of adhesion on the static friction is discussed and found to be negligible at plasticity index values larger than 2. It is shown that the classical laws of friction are a limiting case of the present more general solution and are adequate only for high plasticity index and negligible adhesion. Some potential limitations of the present model are also discussed pointing to possible improvements. A comparison of the present results with those obtained from an approximate CEB friction model shows substantial differences, with the latter severely underestimating the static friction coefficient.

scholarly journals Study of Dynamics of Block-Media in the Framework of Minimalistic Numerical Models

2020 ◽  
pp. 143-168
Author(s):  
Alexander E. Filippov ◽  
Valentin L. Popov
Keyword(s):  
Numerical Models ◽  
Seismic Energy ◽  
Static Friction ◽  
Stability Diagram ◽  
Friction Model ◽  
Low Energy ◽  
Stick Slip ◽  
State Dependent ◽  
Proposed Model ◽  
Characteristic Features

AbstractOne of the principal methods of preventing large earthquakes is stimulation of a large series of small events. The result is a transfer of the rapid tectonic dynamics in a creep mode. In this chapter, we discuss possibilities for such a transfer in the framework of simplified models of a subduction zone. The proposed model describes well the basic characteristic features of geo-medium behavior, in particular, statistics of earthquakes (Gutenberg Richter and Omori laws). Its analysis shows that local relatively low-energy impacts can switch block dynamics from stick–slip to creep mode. Thus, it is possible to change the statistics of seismic energy release by means of a series of local, periodic, and relatively low energy impacts. This means a principal possibility of “suppressing” strong earthquakes. Additionally, a modified version of the Burridge-Knopoff model including a simple model for state dependent friction force is derived and studied. The friction model describes a velocity weakening of friction between moving blocks and an increase of static friction during stick periods. It provides a simplified but qualitatively correct stability diagram for the transition from smooth sliding to a stick–slip behavior as observed in various tribological systems. Attractor properties of the model dynamic equations were studied under a broad range of parameters for one- and two-dimensional systems.

Sign in / Sign up

Export Citation Format

Share Document