Robust Nonlinear Stick-Slip Friction Compensation

1991 ◽  
Vol 113 (4) ◽  
pp. 639-645 ◽  
Author(s):  
S. C. Southward ◽  
C. J. Radcliffe ◽  
C. R. MacCluer
Keyword(s):  
Friction Force ◽  
Direct Method ◽  
Piecewise Linear ◽  
Static Friction ◽  
Force Term ◽  
Stick Slip ◽  
Servo Systems ◽  
Stability And Control ◽  
Nonlinear Compensation ◽  
And Control

A nonlinear compensation force for stick-slip friction is developed to supplement a proportional + derivative control law applied to a one-degree-of-freedom mechanical system. Inertial control objects acted on by stick-slip friction are common mechanical components in mechanical servo systems and the conceptual model chosen for this investigation is a mass sliding on a rough surface. The choice of a discontinuous compensation force is motivated by the requirement that the desired reference be a unique equilibrium point of the system. The stick-slip friction force, modelled with a sticking force term and a slipping force term, generates discontinuous state derivatives. A Lyapunov function is introduced to prove global asymptotic stability of the desired reference using a modification of the direct method for discontinuous systems. Stability is verified numerically as well as experimentally. The nonlinear compensation force is robust with respect to the character of the slipping force which is assumed to lie within a piecewise linear band. Exact knowledge of the static friction force levels is not required, only upper bounds for these levels. Stability and control effectiveness is verified analytically, numerically and experimentally on a laboratory test stand.

Compensation of Stick-Slip Phenomenon in an Electrical Actuator

2003 ◽  
Vol 15 (4) ◽  
pp. 398-405 ◽  
Author(s):  
R. Merzouki ◽  
◽  
J. C. Cadiou ◽  
N. K. M'Sirdi
Keyword(s):  
Friction Force ◽  
Static Friction ◽  
Adaptive Controller ◽  
Nonlinear Observer ◽  
Convergence To Equilibrium ◽  
Dynamic Friction ◽  
Slip Effect ◽  
Stick Slip ◽  
Electrical Actuator ◽  
Slip Phenomenon

In mechanical systems involving low-speed motion, consisting of a succession of jumps and stops, as in trained wagons or manipulated robots, control usually exhibits error when the static friction force exceeds the dynamic friction force in what is known as the stick-slip effect. We developed a nonlinear observer to determine the friction force of contact during motion and to compensate for its effect. Simulation and experimental results show global convergence to equilibrium and good performance by the adaptive controller.

A Numerical Simulation of Interfacial Slip and its Role in Friction

2012 ◽  
Author(s):  
Jeffrey L. Streator
Keyword(s):  
Friction Coefficient ◽  
Friction Force ◽  
Lateral Displacement ◽  
Reaction Force ◽  
Static Friction ◽  
Constant Load ◽  
Interfacial Slip ◽  
Stick Slip ◽  
Elastic Slab ◽  
Static Coefficient Of Friction

The transition from static friction to kinetic friction results from the attainment of a point of instability, whereby interfacial slip becomes more energetically favorable than sticking. Such an instability is explored in this work via a plane-strain elastostatic analysis. A rigid pin of prescribed geometry is placed in contact with an elastic slab and translated horizontally under conditions of constant load. An intrinsic static coefficient of friction is prescribed, which limits the ratio of shear stress to contact pressure at each location within the interface. Additionally, the surface of the elastic slab is given a desired undulation to simulate the effects of surface roughness. As the pin is translated horizontally, a lateral reaction force (i.e., friction force) is developed and is observed to grow nearly linearly with increasing lateral displacement. At a critical point, a substantial portion of the interface experiences slip, leading to a large decrease in the friction force and thereby revealing a stick-slip behavior. It is found that the overall (macroscopic) static friction coefficient can be significantly less than the intrinsic friction coefficient and that the presence of even a small amount of roughness can have a large effect on the friction force.

Analytical Dynamics of a Piecewise Linear Friction Oscillator Under a Periodic Excitation

2005 ◽  
Author(s):  
Albert C. J. Luo ◽  
Patrick Zweigart
Keyword(s):  
Friction Force ◽  
Piecewise Linear ◽  
Static Friction ◽  
Friction Model ◽  
Analytical Dynamics ◽  
Periodic Motions ◽  
Input And Output ◽  
Output Force ◽  
Linear Friction ◽  
Friction Oscillator

This paper presented a methodology to determine the analytical dynamics of the periodically forced friction oscillator. The friction force is modeled by a piecewise linear, kinetic friction model with the static force. The input and output force concepts in the vicinity of the discontinuous friction force boundary are introduced. The force criteria for the onset and vanishing of stick and non-stick motions are presented through the input and output forces. The periodic motion of such an oscillator is determined through the corresponding mapping structure. The local stability of the periodic motions is presented. Illustrations of the periodic motions in such a piecewise friction model are given for better understanding the stick motion with static friction. The force responses are presented, which agreed very well with the force criteria.

Nonlinear analysis of stability and control for an F-16 configuration

1997 ◽  
Author(s):  
Zhongjun Wang ◽  
Zhidai He ◽  
C. Lan ◽  
Zhongjun Wang ◽  
Zhidai He ◽  
...  
Keyword(s):  
Nonlinear Analysis ◽  
Stability And Control ◽  
Analysis Of Stability ◽  
And Control

Designing Stability and Control Augmentation Systems Using Genetic Algorithms

2009 ◽  
Author(s):  
Ashraf Omran ◽  
Mohamed Elshabasy ◽  
Wael Mokhtar ◽  
Brett Newman ◽  
Mohamed Gharib
Keyword(s):  
Genetic Algorithms ◽  
Stability And Control ◽  
And Control

scholarly journals Method for designing multi-input system identification signals using a compact time-frequency representation

2021 ◽  
Author(s):  
Mathias Stefan Roeser ◽  
Nicolas Fezans
Keyword(s):  
System Identification ◽  
Design Method ◽  
Flight Test ◽  
Compact Representation ◽  
Time Frequency ◽  
Stability And Control ◽  
Frequency Representation ◽  
Aerodynamic Parameters ◽  
Definition Of ◽  
And Control

AbstractA flight test campaign for system identification is a costly and time-consuming task. Models derived from wind tunnel experiments and CFD calculations must be validated and/or updated with flight data to match the real aircraft stability and control characteristics. Classical maneuvers for system identification are mostly one-surface-at-a-time inputs and need to be performed several times at each flight condition. Various methods for defining very rich multi-axis maneuvers, for instance based on multisine/sum of sines signals, already exist. A new design method based on the wavelet transform allowing the definition of multi-axis inputs in the time-frequency domain has been developed. The compact representation chosen allows the user to define fairly complex maneuvers with very few parameters. This method is demonstrated using simulated flight test data from a high-quality Airbus A320 dynamic model. System identification is then performed with this data, and the results show that aerodynamic parameters can still be accurately estimated from these fairly simple multi-axis maneuvers.

On Time-Synchronized Stability and Control

2021 ◽  
pp. 1-14
Author(s):  
Dongyu Li ◽  
Haoyong Yu ◽  
Keng Peng Tee ◽  
Yan Wu ◽  
Shuzhi Sam Ge ◽  
...  
Keyword(s):  
Stability And Control ◽  
And Control
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