A Model Based Computationally Efficient Method for On-Line Detection of Chatter in Milling

2013 ◽  
Author(s):  
Lei Ma ◽  
Shreyes Melkote ◽  
James Castle
Keyword(s):  
Efficient Method ◽  
Chip Thickness ◽  
Line Detection ◽  
Chatter Detection ◽  
Computationally Efficient ◽  
Model Based ◽  
Force Signal ◽  
On Line ◽  
Regeneration Effect ◽  
Milling Chatter

This paper presents a model-based computationally efficient method for detecting milling chatter in its incipient stages. Based on a complex exponentials model for the dynamic chip thickness, the chip regeneration effect is amplified and isolated from the cutting force signal for early chatter detection. The proposed method is independent of the cutting conditions. With the aid of a one tap adaptive filter, the proposed method is also found to be able to distinguish between chatter and the dynamic transients in the cutting forces due to sudden changes in workpiece geometry and tool entry/exit. The proposed method is experimentally validated.

A Model-Based Computationally Efficient Method for On-Line Detection of Chatter in Milling

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Lei Ma ◽  
Shreyes N. Melkote ◽  
James B. Castle
Keyword(s):  
Cutting Force ◽  
Efficient Method ◽  
Frequency Estimation ◽  
Chip Thickness ◽  
Computationally Efficient ◽  
Model Based ◽  
Chatter Suppression ◽  
Force Signal ◽  
Regeneration Effect ◽  
Milling Chatter

This paper presents a model-based computationally efficient method for detecting milling chatter in its incipient stages and for chatter frequency estimation by monitoring the cutting force signals. Based on a complex exponentials model for the dynamic chip thickness, the chip regeneration effect is amplified and isolated from the cutting force signal for early chatter detection. The proposed method is independent of the cutting conditions. With the aid of a one tap adaptive filter, the method is shown to be capable of distinguishing between chatter and the dynamic transients in the cutting forces arising from sudden changes in workpiece geometry and tool entry/exit. To facilitate chatter suppression once the onset of chatter is detected, a time domain algorithm is proposed so that the dominant chatter frequency can be accurately determined without using computationally expensive frequency domain transforms such as the Fourier transform. The proposed method is experimentally validated.

On-Line Grinding Chatter Detection Based on Minimum Entropy Deconvolution and Autocorrelation Function

2021 ◽  
Author(s):  
Dan He ◽  
Zexing Ni ◽  
Xiufeng Wang
Keyword(s):  
Autocorrelation Function ◽  
Line Detection ◽  
Detection Accuracy ◽  
Minimum Entropy ◽  
Chatter Detection ◽  
Vibration Signals ◽  
Grinding Chatter ◽  
Grinding Conditions ◽  
On Line ◽  
Periodic Impulse

Abstract On-line detection of chatter is one of the key techniques to avoid the harmful effects caused by chatter in grinding process. The key to chatter detection is to capture reliable chatter features and thresholds. To achieve this, it is important to make clear and extract the essential characteristics of the grinding chatter signal, which has not yet been well studied. In this paper, we are going to investigate the essential characteristics of the grinding chatter signal and propose a new approach for on-line detection of grinding chatter. The proposed approach for on-line detection of grinding chatter is based on minimum entropy deconvolution and autocorrelation function, in which the minimum entropy deconvolution is employed to deconvolve the effect of transmission path, and further to restore the essential characteristics of the chatter signals. To eliminate the interference of the non-periodic impulse signals in the measured vibration signals, an autocorrelation function is introduced. Kurtosis is employed to indicate chatter according to the changes of the processed signal. The validity of the proposed method is demonstrated through the measured vibration signals obtained from grinding processes and the presented chatter detection index is independent from the grinding conditions with excellent detection accuracy and permissible computational efficiency. This demonstrates the effectiveness of proposed method in on-line implementation.

Investigation on Adaptive Filter for On-Line Detection and Active Control of Chatter Vibration in Milling Process

2019 ◽  
Author(s):  
Shaoke Wan ◽  
Xiaohu Li ◽  
Wenjun Su ◽  
Jun Hong
Keyword(s):  
Active Control ◽  
Adaptive Filter ◽  
Rotation Frequency ◽  
Milling Process ◽  
Spindle Speed ◽  
Line Detection ◽  
Spindle Rotation ◽  
On Line ◽  
Milling Chatter ◽  
Periodic Components

Abstract On-line detection and active control of chatter vibration have always been important issues in milling process respectively. To some extent, the signals obtained with sensors determine the performance of on-line detection and active control of chatter. However, due to the characteristics of milling process, the obtained signals are mainly consisted with spindle rotation frequency and its harmonics, and the chatter components are usually submerged by these stable harmonics, imposing negative effects for the detection and active control of milling chatter. Then, it is highly needed to design a real-time filter to filter out the spindle rotation frequency and its harmonics. In this paper, an adaptive filter is designed to filter out the spindle speed related components. Moving average (MR) model and adaptive filter theory is utilized to estimate these periodic components. The influence of filter order and step size factor on the filter characteristics are also analyzed. Considering that the filter order needs to be adjusted under different cutting conditions, which will alter the filter’s performance, an improved adaptive filter is proposed. Experiments are also performed and the experimental results show that, not only the spindle speed related components can be filtered out effectively, but the chatter frequency components are amplified with appropriate initial step factor, which is beneficial for the detection of milling chatter at early stage. Meanwhile, the periodic components caused by the installation error and the other spindle speed related components can be effectively filtered out real-timely, preventing the saturation of actuator caused by these stable components.

On-Line Energy-Based Milling Chatter Detection

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Hakan Caliskan ◽  
Zekai Murat Kilic ◽  
Yusuf Altintas
Keyword(s):  
Fourier Transforms ◽  
Energy Operator ◽  
Forced Vibrations ◽  
Chatter Detection ◽  
Line Energy ◽  
Natural Modes ◽  
Chatter Vibrations ◽  
On Line ◽  
Milling Chatter ◽  
Periodic Components

Milling exhibits forced vibrations at tooth passing frequency and its harmonics, as well as chatter vibrations close to one of the natural modes. In addition, there are sidebands, which are spread at the multiples of tooth passing frequency above and below the chatter frequency, and make the robust chatter detection difficult. This paper presents a novel on-line chatter detection method by monitoring the vibration energy. Forced vibrations are removed from the measurements in discrete time domain using a Kalman filter. After removing all periodic components, the amplitude and frequency of chatter are searched in between the two consecutive tooth passing frequency harmonics using a nonlinear energy operator (NEO). When the energy of any chatter component grows relative to the energy of forced vibrations, the presence of chatter is detected. The proposed method works in discrete real time intervals, and can detect the chatter earlier than frequency domain-based methods, which rely on fast Fourier Transforms. The method has been experimentally validated in several milling tests using both microphone and accelerometer measurements, as well as using spindle speed and current signals.

A Modified Dugoff Tire Model for Combined-slip Forces

2010 ◽  
Vol 38 (3) ◽  
pp. 228-244 ◽  
Author(s):  
Nenggen Ding ◽  
Saied Taheri
Keyword(s):  
Vehicle Dynamics ◽  
Tire Model ◽  
Magic Formula ◽  
Model Based ◽  
Proposed Model ◽  
Road Friction ◽  
On Line ◽  
Double Lane Change ◽  
Tire Forces ◽  
Tire Models

Abstract Easy-to-use tire models for vehicle dynamics have been persistently studied for such applications as control design and model-based on-line estimation. This paper proposes a modified combined-slip tire model based on Dugoff tire. The proposed model takes emphasis on less time consumption for calculation and uses a minimum set of parameters to express tire forces. Modification of Dugoff tire model is made on two aspects: one is taking different tire/road friction coefficients for different magnitudes of slip and the other is employing the concept of friction ellipse. The proposed model is evaluated by comparison with the LuGre tire model. Although there are some discrepancies between the two models, the proposed combined-slip model is generally acceptable due to its simplicity and easiness to use. Extracting parameters from the coefficients of a Magic Formula tire model based on measured tire data, the proposed model is further evaluated by conducting a double lane change maneuver, and simulation results show that the trajectory using the proposed tire model is closer to that using the Magic Formula tire model than Dugoff tire model.

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