scholarly journals GPU-accelerated meshfree simulations for parameter identification of a friction model in metal machining

2020 ◽  
Vol 176 ◽  
pp. 105571 ◽  
Author(s):  
M. Afrasiabi ◽  
L. Meier ◽  
M. Röthlin ◽  
H. Klippel ◽  
K. Wegener
Keyword(s):  
Parameter Identification ◽  
Friction Model ◽  
Metal Machining

Carbon Brake Friction Model Parameter Identification Using Genetic Algorithms

1995 ◽  
Author(s):  
Roger C. von Doenhoff ◽  
Robert J. Streifel ◽  
Robert J. Marks
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Surface Temperature ◽  
Parameter Identification ◽  
Friction Model ◽  
Carbon Surface ◽  
Model Parameters ◽  
Model Parameter ◽  
Brake Pressure ◽  
Model Parameter Identification

Abstract A model of the friction characteristics of carbon brakes is proposed to aid in the understanding of the causes of brake vibration. The model parameters are determined by a genetic algorithm in an attempt to identify differences in friction properties between brake applications during which vibration occurs and those during which there is no vibration. The model computes the brake torque as a function of wheelspeed, brake pressure, and the carbon surface temperature. The surface temperature is computed using a five node temperature model. The genetic algorithm chooses the model parameters to minimize the error between the model output and the torque measured during a dynamometer test. The basics of genetic algorithms and results of the model parameter identification process are presented.

scholarly journals Study on the Low Velocity Stability of a Prostate Seed Implantation Robot’s Rotatory Joint

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 284 ◽  
Author(s):  
Bing Li ◽  
Yongde Zhang ◽  
Lipeng Yuan ◽  
Xiaolin Xi
Keyword(s):  
Prostate Cancer ◽  
Parameter Identification ◽  
Control Method ◽  
Friction Model ◽  
Friction Torque ◽  
Low Velocity ◽  
Seed Implantation ◽  
Compensation Control ◽  
Lugre Friction Model ◽  
Lugre Friction

Prostate cancer has one of the highest incidences of male malignant tumors worldwide. Its treatment involves the robotic implantation of radioactive seeds in the perineum, a safe and effective procedure for early, low-risk prostate cancer. In order to ensure precise positioning, the seed implantation needle is set at low terminal velocity. In this paper, the motion output position instability caused by the friction torque of the robot’s motor and rotating joint during low velocity motion was analyzed and studied. This paper also presents a compensation control method based on the LuGre friction model, which offers piecewise parameter identification with GA-PSO. First, based on an analysis of its structure and working principle, the friction torque model of the robotic system and the torque model of the driving motor are established, and the influence of friction torque on motion stability analyzed. Then, based on experimental data of the relationship between velocity and friction torque for no-friction compensation, the velocity point of the minimum torque of the rotating joint and the critical Stribeck velocity point were used for segmental parameter identification; cubic spline interpolation was used for segmental fitting. Furthermore, on the basis of the LuGre model identification method, parameter identification of the genetic algorithm-particle swarm optimization, and compensation control of the LuGre friction model, a control method is analysed and set forth. Malab2017a/Simulink simulation software was used to simulate and analyze the control method, and verify its feasibility. Finally, the cantilever prostate seed implantation robot system was tested to verify the effectiveness of the segmented identification method and the compensation control strategy. The results reveal that motion output position stability at low velocity meets the requirements of the cantilever prostate seed implantation robot, thus providing a vital reference for further research.

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.

Identification of Wear Coefficient in Archard Model Based on LuGre Friction Model

2011 ◽  
Vol 343-344 ◽  
pp. 28-32
Author(s):  
Xu Zeng ◽  
Shu Guang Zuo ◽  
Xu Dong Wu
Keyword(s):  
Parameter Identification ◽  
Dynamic Model ◽  
Friction Model ◽  
Road Surface ◽  
Computational Method ◽  
Wear Coefficient ◽  
Experiment Data ◽  
Lugre Friction Model ◽  
Tire Wear ◽  
Lugre Friction

Considering the mechanism interaction between the tire tread and road surface, a dynamic model is established based on LuGre friction model in this paper. The parameter identification of wear coefficient in Archard model is proceeded by simulation in accordance with the experiment data in the correlative references based on the computational method of abrasion loss in Archard model. The results show that this model can fit the experiment data well, provide a theoretic instruction to fulfill the tire wear prediction and lay the foundation of further research in this field.

High Performance Adaptive Control of Mechanical Servo System With LuGre Friction Model: Identification and Compensation

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Xingjian Wang ◽  
Shaoping Wang
Keyword(s):  
Adaptive Control ◽  
Parameter Identification ◽  
Control Algorithm ◽  
Servo System ◽  
Friction Model ◽  
Friction Compensation ◽  
Lugre Friction Model ◽  
Identification Technique ◽  
Lugre Friction ◽  
Adaptive Control Algorithm

LuGre dynamic friction model has been widely used in servo system for friction compensation, but it increases the difficulty of controller design because its parameters are difficult to be identified and its internal state is immeasurable. This paper presents a parameter identification technique based on novel evolutionary algorithm (NEA) for LuGre friction model. In order to settle the practical digital implementation problem of LuGre model, this paper also proposes a modified dual-observer with discontinuous mapping and smooth transfer function. On the basis of the parameter identification results and the modified dual-observer, this paper designs an adaptive control algorithm with dynamic friction compensation for hydraulic servo system. The comparative experiments indicate that the proposed parameter identification technique and the adaptive control algorithm with modified dual-observer are effective with high tracking performance.

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