Friction-model-based estimation of interaction force of a surgical robot

2015 ◽  
Author(s):  
Subon Kim ◽  
Doo Yong Lee
Keyword(s):  
Interaction Force ◽  
Friction Model ◽  
Surgical Robot ◽  
Model Based

A new identification method of the Stribeck friction model based on limit cycles

2014 ◽  
Vol 228 (15) ◽  
pp. 2678-2683 ◽  
Author(s):  
LL Liu ◽  
ZY Wu
Keyword(s):  
Parameter Identification ◽  
Limit Cycle ◽  
Limit Cycles ◽  
Friction Model ◽  
Limit Cycle Oscillation ◽  
Characteristic Parameters ◽  
Chain Code ◽  
Shape Characteristic ◽  
Identification Method ◽  
Model Based

This paper presents a new parameter identification method of the Stribeck friction model based on limit cycles. A single degree of freedom mass spring system driven by a belt is studied, and the Stribeck friction model is established between the mass and belt. Limit cycle oscillation will occur when the system is unstable. The limit cycle curve is described by some main shape characteristic parameters using the modified Freeman chain code method. Thus, the Stribeck friction parameters can be identified by using the ergodic search method to minimize the Euclidean distance of the theoretical and identified limit cycle shape characteristic parameters. The parameter identification method based on limit cycles is different from the traditional identification methods. It only needs the displacement and velocity responses of the system instead of the measurement of the friction force or motor voltage/current. All of these works can provide the reference for the research work of the friction parameter identification.

scholarly journals Model Predictive Torque Control for Velocity Tracking of a Four-Wheeled Climbing Robot

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7059
Author(s):  
Higor Barbosa Santos ◽  
Marco Antonio Simoes Teixeira ◽  
Nicolas Dalmedico ◽  
Andre Schneider de Oliveira ◽  
Flavio Neves-Jr ◽  
...  
Keyword(s):  
Dynamic Models ◽  
Nonlinear Effects ◽  
Interaction Force ◽  
Torque Control ◽  
Climbing Robot ◽  
Kinematic Modeling ◽  
Model Based ◽  
Climbing Ability ◽  
Nonlinear Dynamic Models ◽  
Velocity Tracking

Climbing robots are characterized by a secure surface coupling that is designed to prevent falling. The robot coupling ability is assured by an adhesion method leading to nonlinear dynamic models with time-varying parameters that affect the robot’s mobility. Additionally, the wheel friction and the force of gravity force are also relevant issues that can compromise the climbing ability if they are not well modeled. This work presents a model-based torque controller for velocity tracking in a four-wheeled climbing robot specially designed to inspect storage tanks. The model-based controller (MPC) compensates for the effects of nonlinearities due to the forces of gravity, friction, and adhesion through the dynamic and kinematic modeling of the climbing robot. Dynamic modeling is based on the Lagrange-Euler approach, which allows a better understanding of how forces and torques affect the robot’s movement. Besides, an analysis of the interaction force between the robot and the contact surface is proposed, since this force affects the motion of the climbing robot according to spatial orientation. Finally, simulations are carried out to examine the robot’s dynamics during the climbing movement, and the MPC is validated through the redrobot simulator V-REP and practical experiments. The presented results highlight the compensation of the nonlinear effects due to the robot’s climbing motion by the proposed MPC controller.

scholarly journals Rate-, state-, and pressure-dependent friction model based on the elastoplastic theory

Friction ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 768-783 ◽  
Author(s):  
Shingo Ozaki ◽  
Takeru Matsuura ◽  
Satoru Maegawa
Keyword(s):  
Friction Force ◽  
Contact Area ◽  
Contact Surface ◽  
Internal State ◽  
Friction Model ◽  
Real Contact Area ◽  
State Variables ◽  
Real Contact ◽  
Model Based ◽  
Acrylic Plate

AbstractAdhesion is one of essences with respect to rubber friction because the magnitude of the friction force is closely related to the magnitude of adhesion on a real contact area. However, the real contact area during sliding depends on the state and history of the contact surface. Therefore, the friction force occasionally exhibits rate-, state-, and pressure dependency. In this study, to rationally describe friction and simulate boundary value problems, a rate-, state-, and pressure-dependent friction model based on the elastoplastic theory was formulated. First, the evolution law for the friction coefficient was prescribed. Next, a nonlinear sliding surface (frictional criterion) was adopted, and several other evolution laws for internal state variables were prescribed. Subsequently, the typical response characteristics of the proposed friction model were demonstrated, and its validity was verified by comparing the obtained results with those of experiments conducted considering the contact surface between a rough rubber hemisphere and smooth acrylic plate.

LuGre Friction Model Based Adaptive Control With Functional Approximation Compensation for a Piezoelectric-Actuating Table

2010 ◽  
Author(s):  
Shiuh-Jer Huang ◽  
Kuan-Lian Her ◽  
Su-Hai Hsiang
Keyword(s):  
System Modeling ◽  
Friction Model ◽  
Hysteretic Behavior ◽  
System Stability ◽  
High Frequency Oscillation ◽  
Control Voltage ◽  
Functional Approximation ◽  
Model Based ◽  
Lugre Friction Model ◽  
Lugre Friction

Since the piezoelectric actuators have the disadvantages of small travel and hysteretic behavior, a long range friction actuating mechanism was designed. The piezoelectric material is used to generate high frequency oscillation for actuating a finger tip which contacted with a slide to induce the back and forth motion. The LuGre friction model is chosen to simulate the dynamics of this friction actuating mechanism. However, this piezoelectric actuating system has obvious nonlinear and time-varying dead-zone offset control voltage due to the static friction and preload. It is difficulty to establish an accurate dynamic model for model-based precision control design. Hence, the functional approximation (FA) scheme is employed to compensate the system modeling error. The Laypunov-like design strategy is adopted to derive the adaptive laws and the system stability criterion. Different trajectories tracking control are planned to investigate the motion control performance and the steady state error of this adaptive controller. The dynamic experimental results of the proposed controller are compared with that of a model-based PID controller.

Sign in / Sign up

Export Citation Format

Share Document