Grinding Process Instability

1969 ◽  
Vol 91 (3) ◽  
pp. 597-606 ◽  
Author(s):  
B. Bartalucci ◽  
G. G. Lisini
Keyword(s):  
Closed Loop ◽  
Experimental Tests ◽  
Grinding Wheel ◽  
Closed Loop System ◽  
Regenerative Effect ◽  
Machine Tool Structure ◽  
Chatter Vibrations ◽  
Grinding Machine ◽  
Theoretical Results ◽  
Good Agreement

The paper describes a theoretical investigation on chatter vibrations of cylindrical plunge grinding. The system grinding machine-grinding wheel-workpiece is represented as a closed loop system with two feedback paths, one due to the machine tool structure, the other to the regenerative effect of the grinding wheel. Theoretical results are in good agreement with the experimental tests.

scholarly journals Eliminating Impulse for Descriptor System by Derivative Output Feedback

2014 ◽  
Vol 2014 ◽  
pp. 1-15
Author(s):  
Jian Li ◽  
Yufa Teng ◽  
Qingling Zhang ◽  
Jinghao Li ◽  
Liang Qiao
Keyword(s):  
Output Feedback ◽  
Closed Loop ◽  
Sufficient Conditions ◽  
Descriptor System ◽  
Closed Loop System ◽  
Feedback Controllers ◽  
Matrix Pencils ◽  
System Equivalence ◽  
Dynamical Order ◽  
Theoretical Results

The problem of impulse elimination for descriptor system by derivative output feedback is investigated in this paper. Based on a novelly restricted system equivalence between matrix pencils, the range of dynamical order of the resultant closed loop descriptor system is given. Then, for the different dynamical order, sufficient conditions for the existence of derivative output feedback to ensure the resultant closed loop system to be impulse free are derived, and the corresponding derivative output feedback controllers are provided. Finally, simulation examples are given to show the consistence with the theoretical results obtained in this paper.

Design and control of a two-dimensional telerobotic system with a haptic interface

2003 ◽  
Vol 217 (3) ◽  
pp. 169-185
Author(s):  
M-G Her ◽  
M Karkoub ◽  
K-S Hsu
Keyword(s):  
Haptic Interface ◽  
Two Dimensional ◽  
Direct Drive ◽  
Closed Loop System ◽  
Human Arm ◽  
Control Scheme ◽  
Reaction Forces ◽  
And Control ◽  
Theoretical Results ◽  
Good Agreement

A model for a ‘master-slave’ two-dimensional telerobotic dynamic system with a haptic interface device is derived. The telerobotic system consists of a ‘master’ robot, which is a direct-drive robot operated by a human arm, and a ‘slave’ robot, which is an x-y type pallet located at a remote site. When the active handle of the master is moved along an arbitrary trajectory, the remote slave duplicates the motion in a constrained or unconstrained environment. The behaviour of the environment is felt by the operator through the active handle of the master. This is achieved by feeding back the disturbance and reaction forces from the environment and the loads to the active handle. Consequently, the operator gets a feel of the task being performed without being physically at the location of the task. A control scheme is devised for the telerobotic system to establish smooth communication between the master and slave robots. This control scheme integrates the dynamics of the human arm, actuators and the environment in the closed-loop system. It was shown that the experimental and the theoretical results are in good agreement and that the design controller is robust to constrained/unconstrained environments.

scholarly journals Robust Synchronization Controller Design for a Class of Uncertain Fractional Order Chaotic Systems

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Lin Wang ◽  
Chunzhi Yang
Keyword(s):  
Fractional Order ◽  
Chaotic Systems ◽  
Closed Loop ◽  
Controller Design ◽  
Sufficient Conditions ◽  
Closed Loop System ◽  
Synchronization Problem ◽  
Robust Synchronization ◽  
Lyapunov Stability Criterion ◽  
Theoretical Results

Synchronization problem for a class of uncertain fractional order chaotic systems is studied. Some fundamental lemmas are given to show the boundedness of a complicated infinite series which is produced by differentiating a quadratic Lyapunov function with fractional order. By using the fractional order extension of the Lyapunov stability criterion and the proposed lemma, stability of the closed-loop system is analyzed, and two sufficient conditions, which can enable the synchronization error to converge to zero asymptotically, are driven. Finally, an illustrative example is presented to confirm the proposed theoretical results.

scholarly journals StochasticH∞Control for Discrete-Time Singular Systems with State and Disturbance Dependent Noise

2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Yong Zhao ◽  
Xiushan Jiang ◽  
Weihai Zhang
Keyword(s):  
Discrete Time ◽  
State Feedback ◽  
Closed Loop ◽  
Singular Systems ◽  
State Feedback Control ◽  
Linear Matrix ◽  
Mean Square ◽  
Matrix Inequalities ◽  
Closed Loop System ◽  
Theoretical Results

This paper is concerned with the stochasticH∞state feedback control problem for a class of discrete-time singular systems with state and disturbance dependent noise. Two stochastic bounded real lemmas (SBRLs) are proposed via strict linear matrix inequalities (LMIs). Based on the obtained SBRLs, a state feedbackH∞controller is presented, which not only guarantees the resulting closed-loop system to be mean square admissible but also satisfies a prescribedH∞performance level. A numerical example is finally given to illustrate the effectiveness of the proposed theoretical results.

Chilled Water Temperature Control of HVAC System Using GPC Based Controller

2012 ◽  
Vol 151 ◽  
pp. 626-631
Author(s):  
Qiang Ma ◽  
Jian Gang Lu ◽  
Qin Min Yang ◽  
Jin Shui Chen ◽  
You Xian Sun
Keyword(s):  
Predictive Control ◽  
Pid Controller ◽  
Closed Loop ◽  
Controller Design ◽  
Simulation Environment ◽  
Closed Loop System ◽  
Satisfactory Performance ◽  
Chilled Water ◽  
The Stability ◽  
Theoretical Results

This work proposes a generalized predictive control (GPC) based controller for the temperature of HVAC chilled water supply. In this paper, several models of evaporator are firstly introduced, wherein an identified black-box model is selected for the purpose of controller design. Based on this model, a GPC based controller is employed to obtain a satisfactory performance even with the presence of disturbance. The theoretical results show the stability of the closed-loop system and the performance of this scheme is compared with that of traditional PID controller under simulation environment.

Stability Switches in a Neutral Delay Differential Equation with Application to Real-Time Dynamic Substructuring

2006 ◽  
Vol 5-6 ◽  
pp. 79-84 ◽  
Author(s):  
Y.N. Kyrychko ◽  
K.B. Blyuss ◽  
A. Gonzalez-Buelga ◽  
S.J. Hogan ◽  
David J. Wagg
Keyword(s):  
Real Time ◽  
Closed Loop ◽  
Numerical Models ◽  
Closed Loop System ◽  
Neutral Delay ◽  
Time Dynamic ◽  
Dynamic Substructuring ◽  
Delay Differential ◽  
Mass Spring ◽  
Theoretical Results

In this paper delay differential equations approach is used to model a real-time dynamic substructuring experiment. Real-time dynamic substructuring involves dividing the structure under testing into two or more parts. One part is physically constructed in the lab- oratory and the remaining parts are being replaced by their numerical models. The numerical and physical parts are connected via an actuator. One of the main difficulties of this testing technique is the presence of delay in a closed loop system. We apply real-time dynamic sub- structuring to a nonlinear system consisting of a pendulum attached to a mass-spring-damper. We will show how a delay can have (de)stabilising effect on the behaviour of the whole system. Theoretical results agree very well with experimental data.

A Study of Uncut Chips Produced by CNT Grinding Wheel

2010 ◽  
Vol 126-128 ◽  
pp. 879-884 ◽  
Author(s):  
Y. Zhang ◽  
Y. Gao ◽  
J. You
Keyword(s):  
Thermal Properties ◽  
Theoretical Study ◽  
Experimental Tests ◽  
Experimental Results ◽  
Machining Process ◽  
Grinding Wheel ◽  
Mechanical And Thermal Properties ◽  
Abrasive Tool ◽  
Nano Structures ◽  
Theoretical Results

Nano structures such as CNTs were proposed to be directly used as cutting grains to fully utilize the nice mechanical and thermal properties for nano machining. To further understand the CNT abrasive tool, a theoretical study of the CNT uncut chip model was conducted together with preliminary experimental tests to investigate the chip generation in the nano machining process. We found that the CNT distribution was not even in the CNT layer of the wheel. Based this finding, a grain spacing model and a feed of workpiece per cutting edge model were developed. Theoretical results were all very small. It was also found that individual workpiece chips were difficult to find due to small sizes. Further work is necessary. Furthermore, Chip gelling effect was found. The reasons were due to agglomeration and epoxy melting. Experimental results were found agree with our theoretical results.

The Increase of the Dynamic and Static Stiffness of a Grinding Machine

2006 ◽  
Author(s):  
Marc Simnofske ◽  
Ju¨rgen Hesselbach
Keyword(s):  
Dynamic Stiffness ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Static Stiffness ◽  
Process Stability ◽  
Chatter Vibrations ◽  
Theoretical Investigations ◽  
The Stability ◽  
Grinding Machine ◽  
Chatter Marks

The dynamic stiffness of a grinding machine influences the process stability enormously. Among other things the stability of the grinding process is affected by influences like the specification of the grinding wheel, the condition of the workpiece and machine parameters. Unfavorable combinations of these lead to chatter vibrations of the machine and chatter marks on the workpiece. This paper presents the results of experimental and theoretical investigations of the vibration behavior of a grinding machine and the design of active modules. These modules will be implemented in the structure of the machine to minimize the vibrations and additionally increase its static stiffness of the machine.

Acoustic Control of Thermoacoustic Instabilities Using Experimental Model-Based Controllers

2001 ◽  
Author(s):  
Daniel Allgood ◽  
Daniel U. Campos-Delgado ◽  
Sumanta Acharya ◽  
Kemin Zhou
Keyword(s):  
Closed Loop ◽  
Control Strategies ◽  
Parametric Identification ◽  
Experimental Models ◽  
Closed Loop System ◽  
Thermoacoustic Instabilities ◽  
Model Based ◽  
Acoustic Control ◽  
Delay Control ◽  
Good Agreement

This paper presents an implementation of active control of thermoacoustic instabilities for a swirl- stabilized spray combustor. Loudspeakers located upstream of the burner were used as control actuators in the closed-loop system. Experimental models of the combustor dynamics were developed using a non-parametric identification method. Several controllers were obtained based on optimal control strategies. These controllers were simulated and tested in the experimental setup showing good agreement. Phase-delay control was used as a baseline method to compare the performance of these different controllers. The advantages of the model-based controllers over the baseline strategy are clearly presented.

scholarly journals Linear Optimal Multi-periodic Repetitive Control - A Low Order Controller Scheme

2011 ◽  
Vol 2 (1) ◽  
pp. 1-16
Author(s):  
Youde HAN ◽  
David H. OWENS ◽  
Bing CHU
Keyword(s):  
Closed Loop ◽  
Repetitive Control ◽  
Reference Signal ◽  
Experimental Tests ◽  
Closed Loop System ◽  
Computational Problem ◽  
Mass Damper ◽  
Periodic Components ◽  
Time Linear ◽  
Repetitive Controller

This article proposes a new method for treating the computational problem in discrete time linear multi-periodic repetitive control systems, where the reference signal includes several periodic components with already known periods.  As periods get large, the computational problem becomes prominent. This work thus investigates the frequency contents of reference signals, where the order of original repetitive controller is lowered by considering only a reduced number of poles, namely, the most important contributors to the total energy of the multi-periodic reference signal. A lower order multi-periodic repetitive controller is designed which assures BIBO stability of the closed-loop system, and approximate tracking is achieved. Finally, experimental tests on a non-minimum phase spring mass damper system demonstrate the effectiveness of this new controller.

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