Prediction of frictional braking noise based on brake dynamometer test and artificial intelligent algorithms

Based on brake noise dynamometer test data, combined with the artificial intelligent algorithms, frictional braking noise is quantitatively analyzed and predicted in this study. To achieve this goal, a frictional braking noise prediction method is indicatively proposed, which consists of two main parts: first, based on the experimental data obtained from the brake noise dynamometer tests, and combining with the improved Long-Short-Term Memory (LSTM) algorithm, the coefficients of friction (COFs) are predicted under various braking test conditions. Then, based on the predicted braking COFs and other selected critical braking parameters, the quantitative prediction of frictional braking noise is obtained by means of the optimized eXtreme Gradient Boosting (XGBoost) algorithm. Finally, the inherent features of the XGBoost algorithm are employed to qualitatively analyze the importance of the main factors affecting the frictional braking noise. The prediction algorithms of COFs and frictional braking noise are validated by the brake dynamomter test data, and the R2 (R square) scores of both the LSTM and XGBoost prediction algorithms are 0.9, which verifies the feasibility of both algorithms. The main contribution of this work is to predict the braking noise based on a large set of test data and combined with the LSTM and XGBoost artificial intelligent algorithms, which can significantly save time for the brake system development and braking performance testing, and has significance to the rapid prediction of braking frictional noise and fast NVH (noise, vibration, and harshness) optimal design of frictional braking systems.

Brake Noise Reduction Method Based on Monte Carlo Sampling and Particle Swarm Optimization

Brake noise is one of the principal components of vehicle noise and is also one of the most critical measures of vehicle quality. During the braking process, the occurrence of brake noise has a significant relationship with the working conditions of the brake system. In the present study, dynamometer test data and the finite element method (FEM) were used to analyze the direct and indirect effects of variations in the working parameters on the brake noise, and a brake noise reduction method was developed. With this method, Monte Carlo sampling was used to consider variations in the parameters of the brake lining during the braking procedure, and the particle swarm optimization method was used to calculate the optimal parameter combination for the brake lining. A dynamometer test was carried out to validate the effect of optimization on brake noise mitigation.

Effect of Compressive Strain of Brake Pads on Brake Noise

Brake noise, a principal component of vehicle noise, is among the most critical measures of vehicle quality. The perceived quality of cars can be improved by reducing brake noise; therefore, vehicle manufacturers are extensively investigating the influencing factors, generating mechanism, and solutions of brake noise. Compressive strain is one of the most influential performance parameters of a brake pad and can be adjusted by regulating the material elastic modulus and by modifying the shape of the brake lining. In this study, the compressive strain of a brake pad was adjusted through four methods, and the noise characteristics of brake pads with different elastic modulus, section outlines, lining widths, and chamfers were studied through finite element analysis and the complex-eigenvalue method. The effects of compressive strain of a brake pad on brake noise were examined, and an optimized brake-pad scheme was developed. A dynamometer test conducted to validate the effectiveness of the optimized scheme confirmed a clear alleviation in brake noise.

INVESTIGATION OF NOISE CHARACTERIZATION OF COATED ROTORS

In this study, four excessive worn brake rotors of a light commercial vehicle are coated using different thickness, methods and powder coatings. Coated rotors ([Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]) compared with OEM brake rotor ([Formula: see text]0) in terms of friction coefficient ([Formula: see text]) and braking noise. Three braking test procedures (bedding, hot judder I and II) are applied to five rotors using inertia brake dynamometer. Results in bedding testing procedures showed that [Formula: see text] rotor provided higher brake noise and higher [Formula: see text] compared with coated rotors. In hot judder I testing procedures, [Formula: see text] rotor provided higher [Formula: see text] and higher brake noi0se compared with the other coated rotors and [Formula: see text]. Also, in hot judder II testing procedures, [Formula: see text] rotor provided higher [Formula: see text] compared with the other rotors, [Formula: see text] provided higher brake noise compared with the other coated rotors. In addition, based on experimental data, noise levels are estimated by multiple regression method with dummy variables.

Comprehensive Analysis on the Performance and Material of Automobile Brake Discs

This article reviews the current status of automotive brake disc research and the prospects for future research. At present, the research of brake disc performance mainly includes thermal conductivity, thermal fatigue resistance, wear resistance, and brake noise. It is found that a new alloy composite, heat treatment process, ceramic composite, new structure, and new materials are emerging. At the same time, it was found that ceramic and resin were used as the matrix, fiber materials were used as reinforcements to prepare brake discs, the addition of new fillers and the study of special reinforcement materials have become new hotspots in the study of brake discs. In the future development, carbon-fiber ceramic brake discs may become the main research focus of brake discs.

Influence of the Friction Block Shape and Installation Angle of High-Speed Train Brakes on Brake Noise

In this study, experiments are conducted to evaluate the effects of friction block shapes and installation angles on the brake noise of high-speed trains on a customized small-scale brake dynamometer. Friction blocks in three different shapes (circle, triangle, and hexagon) and triangular/hexagonal friction blocks at different installation angles are used in the tests. The results indicate that the circular and triangular blocks exhibit low sound pressure with multiple harmonics, whereas the hexagonal friction block produces the highest sound pressure with a single dominant frequency. This difference is attributed to the high contact pressure and severe wear on the surface of the hexagonal friction block. Differences in the installation angle of the triangular/hexagonal friction blocks affect wear debris behavior, distribution of contact pressure, and contact state of the friction interface, consequently influencing noise performance.