On the Use of Two Channels for Bilateral Telemanipulation

2000 ◽  
Author(s):  
Kevin B. Fite ◽  
John E. Speich ◽  
Michael Goldfarb
Keyword(s):  
Feedback Control ◽  
Control Problem ◽  
Frequency Domain ◽  
Degree Of Freedom ◽  
Control Loop ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Stability Robustness ◽  
The Stability ◽  
Loop Form

Abstract A two-channel architecture is presented for the control of a bilateral telemanipulation system. The use of two channels enables the authors to cast the control problem in a classical unity-feedback control loop form, which in turn enables the use of frequency-domain loop shaping techniques. Specifically, the human-manipulators-environment loop can be supplemented with a compensator of a lead/lag form, which can be utilized to simultaneously increase the stability robustness and the transparency bandwidth of the system. This design approach is illustrated with a single-degree-of-freedom example.

On the Natural Modes and Their Stability in Nonlinear Two-Degree-of-Freedom Systems

1959 ◽  
Vol 26 (3) ◽  
pp. 377-385
Author(s):  
R. M. Rosenberg ◽  
C. P. Atkinson
Keyword(s):  
Free Vibrations ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Natural Modes ◽  
Theoretical Predictions ◽  
Stability Chart ◽  
The Stability ◽  
Two Parameters ◽  
Two Degree Of Freedom

Abstract The natural modes of free vibrations of a symmetrical two-degree-of-freedom system are analyzed theoretically and experimentally. This system has two natural modes, one in-phase and the other out-of-phase. In contradistinction to the comparable single-degree-of-freedom system where the free vibrations are always orbitally stable, the natural modes of the symmetrical two-degree-of-freedom system are frequently unstable. The stability properties depend on two parameters and are easily deduced from a stability chart. For sufficiently small amplitudes both modes are, in general, stable. When the coupling spring is linear, both modes are always stable at all amplitudes. For other conditions, either mode may become unstable at certain amplitudes. In particular, if there is a single value of frequency and amplitude at which the system can vibrate in either mode, the out-of-phase mode experiences a change of stability. The experimental investigation has generally confirmed the theoretical predictions.

RESONANCE CONTROL FOR A FORCED SINGLE-DEGREE-OF-FREEDOM NONLINEAR SYSTEM

2004 ◽  
Vol 14 (04) ◽  
pp. 1423-1429 ◽  
Author(s):  
ANDREW Y. T. LEUNG ◽  
JIN CHEN JI ◽  
GUANRONG CHEN
Keyword(s):  
Feedback Control ◽  
Nonlinear System ◽  
Singularity Theory ◽  
Degree Of Freedom ◽  
Theory Approach ◽  
Nonlinear Feedback ◽  
Single Degree Of Freedom ◽  
Weakly Nonlinear ◽  
Single Degree ◽  
Resonance Control

The main characteristic of a forced single-degree-of-freedom weakly nonlinear system is determined by its primary, super- and sub-harmonic resonances. A nonlinear parametric feedback control is proposed to modify the steady-state resonance responses, thus to reduce the amplitude of the response and to eliminate the saddle-node bifurcations that take place in the resonance responses. The nonlinear gain of the feedback control is determined by analyzing the bifurcation diagrams associated with the corresponding frequency-response equation, from the singularity theory approach. It is shown by illustrative examples that the proposed nonlinear feedback is effective for controlling three kinds of resonance responses.

Resonances of a Nonlinear Single-Degree-of-Freedom System with Time Delay in Linear Feedback Control

2010 ◽  
Vol 65 (5) ◽  
pp. 357-368 ◽  
Author(s):  
Atef F. El-Bassiouny ◽  
Salah El-Kholy
Keyword(s):  
Steady State ◽  
Time Delay ◽  
Feedback Control ◽  
Fixed Points ◽  
Multiple Scales ◽  
Degree Of Freedom ◽  
Linear Feedback ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Subharmonic Resonances

The primary and subharmonic resonances of a nonlinear single-degree-of-freedom system under feedback control with a time delay are studied by means of an asymptotic perturbation technique. Both external (forcing) and parametric excitations are included. By means of the averaging method and multiple scales method, two slow-flow equations for the amplitude and phase of the primary and subharmonic resonances and all other parameters are obtained. The steady state (fixed points) corresponding to a periodic motion of the starting system is investigated and frequency-response curves are shown. The stability of the fixed points is examined using the variational method. The effect of the feedback gains, the time-delay, the coefficient of cubic term, and the coefficients of external and parametric excitations on the steady-state responses are investigated and the results are presented as plots of the steady-state response amplitude versus the detuning parameter. The results obtained by two methods are in excellent agreement

Loop Shaping for Transparency and Stability Robustness in Time-Delayed Bilateral Telemanipulation

2004 ◽  
Vol 126 (3) ◽  
pp. 650-656 ◽  
Author(s):  
Kevin B. Fite and ◽  
Michael Goldfarb ◽  
Angel Rubio
Keyword(s):  
Time Delay ◽  
Communication Channels ◽  
Smith Predictor ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Stability Robustness ◽  
Loop Shaping ◽  
And Performance ◽  
Control Methodology

This paper presents a control methodology that provides transparency and stability robustness in bilateral telemanipulation systems that include a significant time delay in the communication channels. The method utilizes an adaptive Smith predictor to compensate for the time delay, and incorporates a previously published loop shaping approach to design a compensator for transparency and stability robustness of the loop. The method is experimentally demonstrated on a single degree-of-freedom telemanipulation system, and is shown to effectively provide stability and performance robustness.

Feedback Control of Grazing-Induced Chaos in the Single-Degree-of-Freedom Impact Oscillator

2017 ◽  
Vol 13 (1) ◽  
Author(s):  
Yongkang Shen ◽  
Shan Yin ◽  
Guilin Wen ◽  
Huidong Xu
Keyword(s):  
Feedback Control ◽  
Control Strategy ◽  
Dynamical Property ◽  
Degree Of Freedom ◽  
Periodic Motions ◽  
Impact Oscillator ◽  
Continuous Transition ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Existence And Stability

Based on the special dynamical property of continuous transition at certain degenerate grazing points in the single-degree-of-freedom impact oscillator, the control problem of the grazing-induced chaos is investigated in this paper. To design degenerate grazing bifurcations, we show how to obtain the degenerate grazing points of the 1/n impact periodic motions by the existence and stability analysis first. Then, a discrete-in-time feedback control strategy is used to suppress the grazing-induced chaos into the 1/n impact periodic motions precisely by the desired degenerate grazing bifurcation. The feasibility of the control strategy is verified by numerical simulations.

Time and frequency domain analyses of single-degree-of-freedom systems

1996 ◽  
Vol 167 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Ajaya K. Gupta ◽  
Tasnim Hassan ◽  
Abhinav Gupta
Keyword(s):  
Frequency Domain ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Single Degree
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