Evaluation and Experimental Validation of Steering Efforts Considering Tire Static Friction Torque and Suspension and Steering Systems Characteristics

2007 ◽  
Author(s):  
D. H Kim ◽  
T. O. Tak ◽  
M. G. Kuk ◽  
J. S. Park ◽  
S. E. Shin ◽  
...  
Keyword(s):  
Experimental Validation ◽  
Static Friction ◽  
Friction Torque

LMI Based Control of Stick-Slip Oscillations in Drilling

2014 ◽  
Author(s):  
Matthew W. Harris ◽  
Behçet Açıkmeşe ◽  
Eric van Oort
Keyword(s):  
Linear Matrix Inequality ◽  
Convex Sets ◽  
Static Friction ◽  
Friction Torque ◽  
Angular Motion ◽  
Linear Matrix ◽  
Model Parameters ◽  
Matrix Inequality ◽  
Stick Slip ◽  
Linear Matrix Inequality Approach

This paper investigates control of stick-slip oscillations in drilling from a linear matrix inequality perspective. Stick-slip oscillations include a period of no angular motion at the bit caused by a large static friction torque followed by a period of rapid angular motion at the bit caused by a build up of torque in the drilling pipe. Many of the model parameters are uncertain but belong to convex sets, and the friction torques are not easily modeled. The linear matrix inequality approach facilitates design of state feedback controllers in the presence of polytopic uncertainties and can be optimized to reject disturbance effects relative to outputs. Results indicate that the linear matrix inequality approach leads to a simple controller, successfully alleviates the stick-slip problem, and is robust to uncertainties.

Torque Analysis and Shape Optimization of Electromagnetic Clutch

2010 ◽  
Vol 426-427 ◽  
pp. 122-126
Author(s):  
Chang Hao Piao ◽  
Z.Y. Huang ◽  
J. Wang ◽  
Chong Du Cho
Keyword(s):  
Static Friction ◽  
Friction Torque ◽  
Geometrical Shape ◽  
Fem Model ◽  
Torque Analysis ◽  
Numerical Process ◽  
Analytical Result ◽  
Electromagnetic Clutch ◽  
Static Torque ◽  
Mathematical Process

This paper is devoted to the static friction torque of electromagnetic clutch. The torque maximization is also investigated by optimizing the geometrical shape of armature. For the purpose of designing and optimizing electromagnetic clutch, torque prediction is a very important factor. We construct an axi-symmetric FEM model to analyze static friction torque and use a torque tester to evaluate real torque. In this work, analytically predicted torque is compared with the experimental one to discuss the rationality of numerical process. The analytical result agrees well with experimental data, which proves the validity of the mathematical process. Through optimization of the shape of armature, we also improve the static torque of electromagnetic clutch about 30%.

scholarly journals The Nonsmooth Vibration of a Relative Rotation System with Backlash and Dry Friction

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Minjia He ◽  
Shuo Li ◽  
Jinjin Wang ◽  
Zhenjun Lin ◽  
Shuang Liu
Keyword(s):  
Dry Friction ◽  
Time History ◽  
Static Friction ◽  
Friction Torque ◽  
Relative Rotation ◽  
Rotation System ◽  
Inclusion Theory ◽  
Nonsmooth Dynamical Systems ◽  
Driving Torque ◽  
Function Time

We investigate a relative rotation system with backlash and dry friction. Firstly, the corresponding nonsmooth characters are discussed by the differential inclusion theory, and the analytic conditions for stick and nonstick motions are developed to understand the motion switching mechanism. Based on such analytic conditions of motion switching, the influence of the maximal static friction torque and the driving torque on the stick motion is studied. Moreover, the sliding time bifurcation diagrams, duty cycle figures, time history diagrams, and the K-function time history diagram are also presented, which confirm the analytic results. The methodology presented in this paper can be applied to predictions of motions in nonsmooth dynamical systems.

scholarly journals The static friction torque compensation of SPG by single resonance pulse

2011 ◽  
Vol 16 ◽  
pp. 119-124
Author(s):  
YANG Jian-Guo ◽  
ZHOU Ren-kui ◽  
LIU Zhao-hui ◽  
LIANG Dong-sheng
Keyword(s):  
Static Friction ◽  
Friction Torque

Development and experimental validation of a mathematical model for friction between fabrics and a volar forearm phantom

2008 ◽  
Vol 222 (7) ◽  
pp. 1097-1106 ◽  
Author(s):  
A M Cottenden ◽  
D J Cottenden ◽  
S Karavokiros ◽  
W K R Wong
Keyword(s):  
Mathematical Model ◽  
Cross Section ◽  
Experimental Validation ◽  
Static Friction ◽  
Nonwoven Fabric ◽  
Elliptical Cross ◽  
Common Assumption ◽  
The Common ◽  
Volar Forearm ◽  
The Relationship

An analytical mathematical model for friction between a fabric strip and the volar forearm has been developed and validated experimentally. The model generalizes the common assumption of a cylindrical arm to any convex prism, and makes predictions for pressure and tension based on Amontons' law. This includes a relationship between the coefficient of static friction ( μ) and forces on either end of a fabric strip in contact with part of the surface of the arm and perpendicular to its axis. Coefficients of friction were determined from experiments between arm phantoms of circular and elliptical cross-section (made from Plaster of Paris covered in Neoprene) and a nonwoven fabric. As predicted by the model, all values of μ calculated from experimental results agreed within ±8 per cent, and showed very little systematic variation with the deadweight, geometry, or arc of contact used. With an appropriate choice of coordinates the relationship predicted by this model for forces on either end of a fabric strip reduces to the prediction from the common model for circular arms. This helps to explain the surprisingly accurate values of μ obtained by applying the cylindrical model to experimental data on real arms.

scholarly journals Research on the peak prediction and intelligent computing of reversal error for the tilt feed system installed on the precision machine tools

2021 ◽  
Vol 2083 (4) ◽  
pp. 042023
Author(s):  
Bin Feng ◽  
ManZhi Yang ◽  
Meng Dang
Keyword(s):  
Prediction Method ◽  
Static Friction ◽  
Friction Torque ◽  
Good Prediction ◽  
Feed System ◽  
Intelligent Computing ◽  
Nc Machine Tool ◽  
Reversal Error ◽  
Nc Machine ◽  
Precision Machine Tools

Abstract To effectively predict the peak of reversal error of tilt feed system and reduce reversal error caused by friction and gravity components, a peak prediction method of reversal error for tilt feed system on the precision NC machine tool is proposed. According to the load, tilt angle, motion trajectory, maximum static friction torque and relevant dynamic characteristic information, the peak prediction formula of the reversal error for the tilt feed system is established by mathematical derivation based on the kinematics, dynamics and torque balance during the process of reversal. Thus, the peak of reversal error for the tilt feed system can be obtained. The experimental results show that this method can achieve a good prediction effect, and can predict the peak of reversal error before the machining. It provides a theoretical basis for the reversal error suppression.

Simulation Analysis of Friction Nonlinear for NC Servo System

2013 ◽  
Vol 274 ◽  
pp. 642-645
Author(s):  
Yu Hong Dong ◽  
Su Ling Tian
Keyword(s):  
Relative Stability ◽  
Simulation Analysis ◽  
Servo System ◽  
Reference Value ◽  
Rotation Velocity ◽  
Static Friction ◽  
Friction Torque ◽  
Tracking Accuracy ◽  
Dynamic Tracking ◽  
The Difference

Friction nonlinear is common in mechatronics system. It can decrease dynamic tracking accuracy, rapidity and relative stability of the system. For NC servo system as an example the simulation analysis is carried out for friction nonlinear. Analyzing friction torque, the difference between dynamic and static friction torques have effects on the system performances. The simulation results illustrate that friction nonlinear mainly affects lower speed track performance of servo system lower. With rotation velocity instruction lower dynamic tracking accuracy and relative stability of servo system more decreasing, the response lag more severity. In the condition of rotation velocity instruction invariable, the bigger the difference between dynamic and static friction torques the worse relative stability and response lag of the system. The paper’s study has the reference value for design and improving lower speed performances of servo system.

scholarly journals Research on Friction Compensation Control for Electric Power Steering System

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Shaosong Li ◽  
Jiafei Niu ◽  
Gaojian Cui ◽  
Zhixin Yu ◽  
Ren Sheng
Keyword(s):  
Control Method ◽  
Static Friction ◽  
Steering System ◽  
Friction Torque ◽  
Friction Compensation ◽  
Compensation Control ◽  
Power Steering ◽  
Electric Power Steering System ◽  
Vehicle Test ◽  
Adaptation Method

A novel friction compensation control method is proposed to compensate both the dynamic and static friction torque of steering system. The change of EPS assist torque under fixed amplitude friction compensation torque can cause the diver’s steering feeling fuzzy. That is due to the fact that the friction torque felt by driver varies with EPS assist gain. Therefore, a further modified friction compensation control method is proposed based on EPS assist gain to make the driver have similar friction feeling. Finally, computer simulation and vehicle test are performed to verify the effectiveness of adaptation method in the proposed controller. Test results indicate that the proposed controller improved the driver’s steering performance.

Experimental validation of the predicted TGR5 binding mode model

2015 ◽  
Vol 53 (01) ◽  
Author(s):  
L Spomer ◽  
CGW Gertzen ◽  
D Häussinger ◽  
H Gohlke ◽  
V Keitel
Keyword(s):  
Experimental Validation ◽  
Binding Mode
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