On the Emulation of Stiff Walls and Static Friction With a Magnetically Levitated Input/Output Device

1997 ◽  
Vol 119 (1) ◽  
pp. 127-132 ◽  
Author(s):  
S. E. Salcudean ◽  
T. D. Vlaar
Keyword(s):  
Haptic Feedback ◽  
Static Friction ◽  
Loss Of Stability ◽  
Pd Controller ◽  
Input Output ◽  
Stick Slip ◽  
Output Device ◽  
Braking Force ◽  
Magnetically Levitated ◽  
Control Implementation

This technical brief addresses issues of mechanical emulation of stiff walls and stick-slip friction with a 6-DOF magnetically levitated joystick. In the case of stiff wall emulation, it is shown that the PD control implementation commonly used severely limits achievable wall damping and stiffness. It is also shown that the perceived surface stiffness can be increased without loss of stability by applying a braking force pulse when crossing into the wall. For stick-slip friction, Karnopp’s model was implemented using a PD controller within the stick friction threshold. Even though the PD controller allows some motion during the stick phase, the haptic feedback provided is remarkably similar to stick-slip friction.

Static Friction Models for Vehicle Simulation Study

2006 ◽  
Author(s):  
Xubin Song ◽  
Daniel G. Smedley
Keyword(s):  
Simulation Study ◽  
Static Friction ◽  
Friction Modeling ◽  
Stick Slip ◽  
Vehicle Simulation ◽  
Engineering Software ◽  
Variable Step ◽  
History Of ◽  
Friction Models ◽  
Smooth Dynamics

The history of the challenge of friction modeling is briefly reviewed. Then this paper focuses on the modeling and simulation study of the friction related dynamics in the Simulink® environment, because Matlab®/Simulink® are popular engineering software tools for both industry and academia. Matlab® and Simulink® are the proprietary products of MathWorks, Inc. In this paper, the static friction models are studied through Simulink® by applying fixed and variable step sizes. The comparison shows that the static Karnopp model is not only numerically tractable but also can be inclusive of the fundamental friction characteristics of both stick slip and correct friction predictions. Finally this paper presents an improved Karnopp model for clutch modeling with the use of Simulink®, and the simulation shows that this model is computationally tractable with smooth dynamics.

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.

Frictional Vibrations

1955 ◽  
Vol 22 (2) ◽  
pp. 207-214
Author(s):  
David Sinclair
Keyword(s):  
Coefficient Of Friction ◽  
Equations Of Motion ◽  
Static Friction ◽  
Uniform Motion ◽  
Friction Characteristic ◽  
Stick Slip ◽  
The Coefficient Of Friction ◽  
Brake Lining ◽  
Solid Bodies ◽  
Frictional Vibrations

Abstract Frictional vibrations, such as stick-slip motion and automobile-brake squeal, which occur when two solid bodies are rubbed together, are analyzed mathematically and observed experimentally. The conditions studied are slow uniform motion and relatively rapid simple harmonic motion of brake lining over a cast-iron base. The equations of motion show and the observations confirm that frictional vibrations are caused primarily by an inverse variation of coefficient of friction with sliding velocity, but their form and occurrence are greatly dependent upon the dynamical constants of the mechanical system. With a constant coefficient of friction, the vibration initiated whenever sliding begins is rapidly damped out, not by the friction but by the “natural” damping of all mechanical systems. The coefficient of friction of most brake linings and other organic materials was essentially invariant with velocity, except that the static coefficient was usually greater than the sliding coefficient. Most such materials usually showed a small decrease in coefficient with increasing temperature. The persistent vibrations resulting from the excess static friction were reduced or eliminated by treating the rubbing surfaces with polar organic compounds which produced a rising friction characteristic.

A multilingual input/output device for Indian scripts

1983 ◽  
Vol 19 (2) ◽  
pp. 137-146 ◽  
Author(s):  
T. Radhakrishnan ◽  
J.W. Atwood ◽  
S.G. Krishnamoorthy
Keyword(s):  
Input Output ◽  
Output Device

Characteristics of Magneto-Rheological Elastomer under Stick-Slip Condition

2020 ◽  
Vol 842 ◽  
pp. 193-198
Author(s):  
Kwang Hee Lee ◽  
Chul Hee Lee
Keyword(s):  
Magnetic Field ◽  
Glass Plate ◽  
Static Friction ◽  
Low Noise ◽  
Friction Behavior ◽  
Stick Slip ◽  
The Difference ◽  
Magneto Rheological ◽  
Squeal Noise ◽  
The Magnetic Field

This paper examines the characteristics of stick-slip phenomena between the glass plate and Magneto-Rheological Elastomer (MRE) surface. Stick-slip phenomena are the spontaneous jerking motion that occurs while two objects are sliding over each other, usually accompanied by noise. Stick-slip is generated when it involves discontinuous frictional degradation when moving from static friction to dynamic friction. The phenomena can lead to uneven wear patterns, vibration and squeal noise which cause a shorter lifespan for the corresponding mechanical elements. MREs are kind of function materials to consist of a polymeric matrix with embedded ferromagnetic particles. Mechanical properties of the MREs can be controlled by the application of magnetic fields. The magnetic field-based controllability can be applied to the control of stick-slip phenomena. The friction experiment is conducted with the Reciprocating Friction Tester (RFT). The sliding speed of the RFT should be in low-speed conditions in order to make the stick-slips relatively easy to occur. A uniform magnetic field and a weight load are applied to the MRE sample to observe the effect of various experimental parameters on the movement of the stick-slip. In addition, frictional sounds due to the stick-slip phenomenon under different loads and magnetic field strength are measured and analyzed. The results of this experiment show that as the strength of the magnetic field increases, the difference in stiffness between the wipers-glass decreases, mitigating fricatives. The result is expected to be well applied to low-noise automotive wipers based on the controllability of friction behavior and squeal noise.

Glitchless Static Friction Models in SIMULINK for Vehicle Simulation Study

2009 ◽  
Vol 5 (1) ◽  
Author(s):  
Xubin Song ◽  
Daniel G. Smedley
Keyword(s):  
Simulation Study ◽  
Static Friction ◽  
Friction Modeling ◽  
Stick Slip ◽  
Vehicle Simulation ◽  
Engineering Software ◽  
Variable Step ◽  
History Of ◽  
Friction Models ◽  
Smooth Dynamics

The history of the challenge of friction modeling is briefly reviewed. Then, this paper focuses on the modeling and simulation study of the friction related dynamics in the SIMULINK® environment, because MATLAB®/SIMULINK® are popular engineering software tools for both industry and academia. MATLAB® and SIMULINK® are the proprietary products of MathWorks, Inc. (Natick, MA). In this paper, the static friction models are studied through SIMULINK® by applying fixed and variable step sizes. The comparison shows that the static Karnopp model is not only numerically tractable but also can be inclusive of the fundamental friction characteristics of both stick-slip and correct friction predictions. Finally, this paper presents an improved Karnopp model for clutch modeling with the use of SIMULINK®, and the simulation shows that this model is computationally tractable with smooth dynamics.

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