Design of a Force Feedback Chatter Control System

1972 ◽  
Vol 94 (1) ◽  
pp. 5-10 ◽  
Author(s):  
C. Nachtigal
Keyword(s):  
Machine Tool ◽  
Frequency Domain ◽  
Transient Response ◽  
Force Feedback ◽  
Design Procedure ◽  
Experimental Tests ◽  
Work Piece ◽  
Regenerative Chatter ◽  
Chatter Control ◽  
The Stability

The analysis of machine tool chatter from frequency domain considerations is generally accepted as a valid representation of the regenerative chatter phenomenon. However, active control of regenerative chatter is still in its embryonic stage. It was established in reference [2] that a measurement of the cutting force could be effectively used in conjunction with a controller and a tool position servo system to increase the stability of an engine lathe and to improve its transient response. This paper presents the design basis for such a system, including both analytical and experimental considerations. The design procedure stems from a real part stability criterion based on the work by Merritt [1]. Because of the unknown variability in the dynamics of a machine tool system, the controller parameters were chosen to accomodate some mismatch between structure and tool servo dynamics. Experimental tests to determine the stability zone of the controlled machine tool system qualitatively confirmed the analytical design results. The experimental results were consistent in that the transient response tests confirmed the frequency domain stability tests. It was also demonstrated experimentally that the equivalent static stiffness of a flexible work-piece system could be substantially increased.

An Analysis and Modeling of the Dynamic Stability of the Cutting Process Against Self-Excited Vibration

2020 ◽  
Vol 22 (4) ◽  
pp. 1287-1300
Author(s):  
A. Motallebia ◽  
A. Doniavi ◽  
Y. Sahebi
Keyword(s):  
Machine Tool ◽  
Removal Rate ◽  
Dimensional Accuracy ◽  
Modal Testing ◽  
Cutting Process ◽  
Work Piece ◽  
Stability Diagrams ◽  
Machine Tool Structure ◽  
Excited Vibration ◽  
The Stability

AbstractChatter is a self-excited vibration which depends on several parameters such as the dynamic characteristics of the machine tool structure, the material of the work piece, the material removal rate, and the geometry of tools. Chatter has an undesirable effect on dimensional accuracy, smoothness of the work piece surface, and the lifetime of tools and the machine tool. Thus, it is useful to understand this phenomenon in order to improve the economic aspect of machining. In the present article, first the theoretical study and mathematical modeling of chatter in the cutting process were carried out, and then by performing modal testing on a milling machine and drawing chatter stability diagrams, we determined the stability regions of the machine tool operation and recognized that witch parameter has a most important effect on chatter.

Stability and Performance of Virtual Reality-Based Telenanomanipulation System in SEM

2011 ◽  
Vol 183-185 ◽  
pp. 1746-1751 ◽  
Author(s):  
Dong Jie Li ◽  
Wei Bin Rong ◽  
Li Ning Sun ◽  
Wan Zhe Xiao
Keyword(s):  
Force Feedback ◽  
Design Procedure ◽  
Haptic Interface ◽  
Human Contact ◽  
Virtual Coupling ◽  
And Performance ◽  
The Stability ◽  
Carbon Nanowires ◽  
Measuring Force ◽  
Scanning Electron

In this paper, a master/slave telenanomanipulation control system with force feedback is established with the micro-positioner (Attocube) working in scanning electron microscope (SEM) as the slave side and the haptic device (Omega3) as the master side. An improved virtual coupling (IVC) algorithm is introduced based on nanoscale virtual coupling (NSVC) by adding a proportional- plus-integral (PI) velocity controller in the haptic interface. The stability and performance of the established system are discussed. This method leads to an explicit design procedure for virtual coupling networks which give greatest performance while guaranteeing stability both on moving carbon nanowires in SEM and measuring force at the point of device-human contact.

scholarly journals An Analysis and Modeling of the Dynamic Stability of the Cutting Process Against Self-Excited Vibration

2019 ◽  
Vol 23 (1) ◽  
pp. 28-35
Author(s):  
A. Motallebia ◽  
A. Doniavi ◽  
Y. Sahebi
Keyword(s):  
Machine Tool ◽  
Removal Rate ◽  
Dimensional Accuracy ◽  
Modal Testing ◽  
Cutting Process ◽  
Work Piece ◽  
Stability Diagrams ◽  
Machine Tool Structure ◽  
Excited Vibration ◽  
The Stability

Abstract Chatter is a self-excited vibration that depends on several parameters such as the dynamic characteristics of a machine tool structure, the material of work piece, the material removal rate, and the geometry of tools. Chatter has an undesirable effect on dimensional accuracy, smoothness of work piece surface, lifetime of tools and machine tools. Thus, it is useful to understand this phenomenon in order to improve the economic aspect of machining. In the present article, firstly, the theoretical study and mathematical modeling of chatter in the cutting process were carried out. Then, by performing modal testing on a milling machine and drawing chatter stability diagrams, we determined the stability regions of the machine tool operation and recognized the parameter that had the most important effect on chatter.

Active Control of Regenerative Chatter During Metal Cutting Process

2005 ◽  
Vol 128 (1) ◽  
pp. 346-349 ◽  
Author(s):  
C. Mei ◽  
J. G. Cherng ◽  
Y. Wang
Keyword(s):  
Frequency Domain ◽  
Metal Cutting ◽  
Hybrid Approach ◽  
Stability Lobe Diagram ◽  
Regenerative Chatter ◽  
Stability Lobe ◽  
The Stability ◽  
The Many ◽  
Frequency Domain Approach ◽  
Frequent Problem

Chatter, a violent relative vibration between a workpiece and a cutting tool, is a frequent problem in a machining operation. Among the many factors which contribute to the problem, regenerative chatter is found to be the most detrimental. Optimal control is designed for suppressing regenerative chatter with the critical regenerative effect taken into account. Furthermore, a novel hybrid time and frequency domain approach is developed for generating the stability lobe diagram for the dynamic system after control, since the conventional frequency domain approach is no longer feasible. Numerical results are obtained in both time and frequency domain for verifying the effectiveness of the controller as well as the hybrid approach for generating the stability lobe diagram.

Development of a Recursive Frequency Based Filter With Application to Chatter Control

1993 ◽  
Author(s):  
Karl B. Ousterhout
Keyword(s):  
Machine Tool ◽  
Real Time ◽  
Digital Signal ◽  
Work Piece ◽  
Machining Processes ◽  
Damping Characteristics ◽  
Analytical Work ◽  
Chatter Control ◽  
Performance Limitation ◽  
Processing Techniques

Abstract In most machining processes, large amounts of energy are needed to accomplish the machining operation. When this energy is transmitted through a structure that has minimal damping characteristics, such as a lathe or a milling machine, self sustained oscillations (chatter) can develop. When chatter develops, it can be viewed as a basic performance limitation of the machine tool. In order to suppress the chatter, a real-time controller using digital signal processing techniques has been implemented. This paper discusses a novel way of computing the transfer function of the machine tool-work piece combination and illustrates how a real-time active chatter controller could be designed and integrated into existing machine tools to overcome this performance limitation. Currently, experimental verification of the analytical work is being pursued.

scholarly journals TECHNOLOGICAL DISTINCTIVE FEATURES PERTAINING TO PROCESS OF SIMULTANEOUS TWO-SIDED MACHINING OF HIGH-PRECESION LENSES HAVING LOW STIFFNESS

2017 ◽  
Vol 16 (3) ◽  
pp. 215-224 ◽  
Author(s):  
A. S. Kozeruk ◽  
I. P. Filonov ◽  
M. I. Filonova ◽  
N. S. Vlasovetz ◽  
D. L. Malpika
Keyword(s):  
Machine Tool ◽  
Central Zone ◽  
Experimental Tests ◽  
Work Piece ◽  
Technological Equipment ◽  
Instrument Making ◽  
Low Stiffness ◽  
Stock Removal ◽  
Tool Diameter

The paper contains substantiated expediency in application of machine tools for manufacturing lenses with low stiffness which make it possible to process simultaneously both actuating surfaces of optical parts. While doing so there is a possibility not only to improve quality of parts due to exclusion of their deformation at the blocking stage but there is also a possibility to ensure significant increase in productivity of the process which pre-supposes shape-formation of high-precision non-process optical elements and also to decrease energy consumption per unit of production. A basic diagram of the machine tool for simultaneous processing of two-sided optical parts with spherical surfaces under conditions of free lapping is presented in the paper. The paper describes the essence of the free lapping method which is one of the most widely used methods in optical instrument-making while obtaining parts with precision actuating surfaces. Methodology for determination of technological equipment settings that ensure uniform stock removal along the whole surface to be machined and also its forced removal as in the central zone of a work-piece, so along its periphery and it is necessary in order to correct macro defects in the form of “hump” or “hole”. The paper proposes methodology for determination of sensitivity in stock removal intensity in respect of changes pertaining to machine tool settings and efficiency of these settings while making corrections of lens macro defects. It has been revealed that maximum sensitivity in stock removal occurs in the case when we change a tool diameter. As for efficiency of the technological equipment settings it has been established that in order to rectify macro defects in the form “hump” or “pit” it is more expedient to change rotation ratio of the tool and the part. Experimental tests on lens processing have been executed and they adequately correlate with the results of theoretical investigations. 

Stability and Online Monitoring of Cutting Chatter: A Review

2011 ◽  
Vol 121-126 ◽  
pp. 377-381
Author(s):  
Yong Liang Zhang ◽  
Zhi Yuan Li
Keyword(s):  
Machine Tool ◽  
Manufacturing Industry ◽  
Online Monitoring ◽  
Rapid Development ◽  
Stability Limit ◽  
Cutting Process ◽  
Work Piece ◽  
Cutting Chatter ◽  
The Stability ◽  
Tool Cutting

Cutting chatter is a kind of severe vibration generating from the interaction of machine tool system and cutting process and it will seriously affect the performance of machine tool and the quality of work piece. With the rapid development towards high precision and automation of the modern manufacturing industry, the stability and monitoring of cutting process have become the hot issues in production and engineering field, lots of useful researches and explorations have been done worldwide. The research situations of stability limit prediction of machine tool cutting system and technology of chatter online monitoring are discussed, the problems and the developing trends are summarized.

Towards a new design with generic modeling and adaptive control of a transformable quadrotor

2021 ◽  
pp. 1-31
Author(s):  
S.H. Derrouaoui ◽  
Y. Bouzid ◽  
M. Guiatni
Keyword(s):  
Adaptive Control ◽  
Control Strategy ◽  
Experimental Tests ◽  
Generic Model ◽  
System Control ◽  
System A ◽  
Viable Solution ◽  
Generic Modeling ◽  
Adaptive Control Strategy ◽  
The Stability

Abstract Recently, transformable Unmanned Aerial Vehicles (UAVs) have become a subject of great interest in the field of flying systems, due to their maneuverability, agility and morphological capacities. They can be used for specific missions and in more congested spaces. Moreover, this novel class of UAVs is considered as a viable solution for providing flying robots with specific and versatile functionalities. In this paper, we propose (i) a new design of a transformable quadrotor with (ii) generic modeling and (iii) adaptive control strategy. The proposed UAV is able to change its flight configuration by rotating its four arms independently around a central body, thanks to its adaptive geometry. To simplify and lighten the prototype, a simple mechanism with a light mechanical structure is proposed. Since the Center of Gravity (CoG) of the UAV moves according to the desired morphology of the system, a variation of the inertia and the allocation matrix occurs instantly. These dynamics parameters play an important role in the system control and its stability, representing a key difference compared with the classic quadrotor. Thus, a new generic model is developed, taking into account all these variations together with aerodynamic effects. To validate this model and ensure the stability of the designed UAV, an adaptive backstepping control strategy based on the change in the flight configuration is applied. MATLAB simulations are provided to evaluate and illustrate the performance and efficiency of the proposed controller. Finally, some experimental tests are presented.

scholarly journals A phase-locked loop using ESO-based loop filter for grid-connected converter: performance analysis

2021 ◽  
Author(s):  
Baoling Guo ◽  
Seddik Bacha ◽  
Mazen Alamir ◽  
Julien Pouget
Keyword(s):  
Performance Analysis ◽  
Frequency Domain ◽  
Low Frequency ◽  
Experimental Tests ◽  
Frequency Measurement ◽  
Phase Locked Loop ◽  
Frequency Domain Analysis ◽  
Loop Filter ◽  
Control Stability ◽  
Unbalanced Grid

AbstractAn extended state observer (ESO)-based loop filter is designed for the phase-locked loop (PLL) involved in a disturbed grid-connected converter (GcC). This ESO-based design enhances the performances and robustness of the PLL, and, therefore, improves control performances of the disturbed GcCs. Besides, the ESO-based LF can be applied to PLLs with extra filters for abnormal grid conditions. The unbalanced grid is particularly taken into account for the performance analysis. A tuning approach based on the well-designed PI controller is discussed, which results in a fair comparison with conventional PI-type PLLs. The frequency domain properties are quantitatively analysed with respect to the control stability and the noises rejection. The frequency domain analysis and simulation results suggest that the performances of the generated ESO-based controllers are comparable to those of the PI control at low frequency, while have better ability to attenuate high-frequency measurement noises. The phase margin decreases slightly, but remains acceptable. Finally, experimental tests are conducted with a hybrid power hardware-in-the-loop benchmark, in which balanced/unbalanced cases are both explored. The obtained results prove the effectiveness of ESO-based PLLs when applied to the disturbed GcC.

scholarly journals Explicit parallel co-simulation approach: analysis and improved coupling method based on H-infinity synthesis

2021 ◽  
Author(s):  
Weitao Chen ◽  
Shenhai Ran ◽  
Canhui Wu ◽  
Bengt Jacobson
Keyword(s):  
Frequency Domain ◽  
Wide Frequency Range ◽  
Coupling Method ◽  
Sampled Data ◽  
H Infinity ◽  
First Case ◽  
Communication Step ◽  
Coupling Variables ◽  
The Stability ◽  
Stability And Accuracy

AbstractCo-simulation is widely used in the industry for the simulation of multidomain systems. Because the coupling variables cannot be communicated continuously, the co-simulation results can be unstable and inaccurate, especially when an explicit parallel approach is applied. To address this issue, new coupling methods to improve the stability and accuracy have been developed in recent years. However, the assessment of their performance is sometimes not straightforward or is even impossible owing to the case-dependent effect. The selection of the coupling method and its tuning cannot be performed before running the co-simulation, especially with a time-varying system.In this work, the co-simulation system is analyzed in the frequency domain as a sampled-data interconnection. Then a new coupling method based on the H-infinity synthesis is developed. The method intends to reconstruct the coupling variable by adding a compensator and smoother at the interface and to minimize the error from the sample-hold process. A convergence analysis in the frequency domain shows that the coupling error can be reduced in a wide frequency range, which implies good robustness. The new method is verified using two co-simulation cases. The first case is a dual mass–spring–damper system with random parameters and the second case is a co-simulation of a multibody dynamic (MBD) vehicle model and an electric power-assisted steering (EPAS) system model. Experimental results show that the method can improve the stability and accuracy, which enables a larger communication step to speed up the explicit parallel co-simulation.

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