1,721,022 research outputs found
AN OBSERVER DESIGN FOR TIME-DELAY CONTROL AND ITS APPLICATION TO DC SERVO MOTOR
No full textThis paper addresses the estimation problem of states and their derivatives for the Time Delay Control (TDC), a robust control technique for nonlinear systems. To this end, an observer design method is presented. Then, in simulations, the controller/observer has been applied to a nonlinear plant, with satisfactory results. Finally, experiments were undertaken on a DC servo motor subject to substantial inertia variations and external disturbances. The results showed that the controller/observer performs quite robustly under those variations and disturbances, and is much less sensitive to sensor noise than the controller using numerical differentiations
Vibration control of a telescopic handler using time delay control and commandless input shaping technique
No full textA telescopic handler is a type of construction machinery used for the loading, transporting and unloading of various forms of cargo. To increase its productivity, the boom of the telescopic handler should be operated at high-speed mode without any occurrence of vibration. Residual vibration, however, in the boom often arises when lifting cargo to higher positions. To solve this problem associated with the occurrence of vibration, we applied time delay control and commandless input shaping technique, which is a modification-based on the concept of Input Shaping Technique. We confirmed their effectiveness through experiments. (C) 2003 Elsevier Ltd. All rights reserved
On improving time-delay control under certain hard nonlinearities
No full textTime-delay control (TDC), owing to its simplicity and unusual performance against parameter variations and disturbances, has been noted and recognized as a promising technique. We have observed, however, that in the presence of so-called hard nonlinearity such as saturation or static friction, TDC reveals some problems commonly found in other methods like PID control or disturbance observer. Specifically, when the system has a saturation limit, TDC shows the windup phenomenon; when static friction and Stribeck effect are dominant, TDC reveals the stick-slip phenomenon. In this paper, we have reported these phenomena associated with TDC, presented their causes, and proposed their remedies. Specifically, through analysis, simulation, and experiment, we have shown that both the phenomena cause serious degradations in control performance; that they result from a common cause, the inherent integral effect in TDC; and that the proposed compensators are effective enough to handle the phenomena. In addition to their effectiveness, the proposed compensators have unusual simplicity and efficiency that matches the positive attributes of the original TDC. (C) 2002 Elsevier Science Ltd. All rights reserved
Lactococus garvieae infection of cultured rainbow trout, Oncorhynchus mykiss , in Taiwan and associated biophysical characteristics and histopathology.
No full textEffect of castration on hair re-growth in Pomeranians with hair cycle arrest (Alopecia X)
No full textDiabetic dogs with concurrent hyperadrenocorticism: a retrospective study of 11 cases during 1995-1999
No full textA reduced order time-delay control for highly simplified brushless DC motor
No full textA reduced order time-delay control is derived and applied to the position control of a brushless DC motor with a highly simplified hardware configuration: use of six-step commutation without current control unit. In addition, the closed-loop stability has been analyzed by using the singular perturbation method. Throughout experimental studies, it is observed that reduced order time delay control effectively compensates for parameter variations and nonlinearities, with a conventional PID control cannot handle with adequate performances. This result shows that reduced order time-delay control enables an economical design without compromising performance. More importantly, the example establishes a case that: a good control method can compensate for the hardware deficiency in a given plant, and as a result it even enables a simpler design of plants at the design stage
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