3,404 research outputs found
A model reference observer for time-delay control and its application to robot trajectory control
No full textThis paper addresses the estimation problem of the states and their derivatives for time-delay control (TDC), a robust control technique for nonlinear systems. To this end, an observer design method is presented. In addition, the sufficient conditions are discussed and implementation Issues are addressed. Finally, experiments were undertaken on a SCARA-type robot subject to substantial inertia variations and external disturbances. The results showed that the controller/observer performs quite robustly under inertia variations and disturbances and is much less sensitive to sensor noise than the controller using numerical differentiations
A concurrent design of input shaping technique and a robust control for high-speed/high-precision control of a chip mounter
No full textInput Shaping Technique (IST) and Time Delay Control (TDC), a robust feedback control law, were combined to achieve fast and precise point-to-point motion of a chip mounter. TDC was used as a feedback control to overcome disturbances and parameter variations, an IST was used to suppress the residual vibration induced in the closed loop system. TDC was designed first for the machine, and a discrete version of IST was designed on the basis of the closed-loop dynamics. In the design of TDC, a better set of gains was available thanks to the use of IST than TDC alone; in the design of IST, too, a better design was possible than IST alone. As the result of the concurrent design and synergy of the two methods, point-to-point motion could be achieved with no overshoot, the settling time of about 0.05 s and few steady-state errors to position commands of 1.5 turn. This result is far better than a conventional PID control or TDC alone could achieve, thereby showing the effectiveness of the concurrent design. (C) 2001 Published by Elsevier Science Ltd
A task-priority based framework for multiple tasks in highly redundant robots
No full textA task-priority based framework for multiple tasks of highly redundant robots was derived using the Lagrangian multiplier method. The framework was proved to prioritize a generic number of tasks without algorithmic problems - so called an algorithmic singularity and an algorithmic error. The computational efficiency of the framework excels other conventional task-priority strategies. The efficiency and efficacy of the framework was demonstrated theoretically and experimentally through comparative study
A robust two-time-scale control design for a pneumatic vibration isolator
No full textThis work was supported by grant No.
R01-2006-000-10872-0 from the Basic Research Program of
the Korea Science & Engineering Foundation
Nonlinear target impedance design and its use in robot compliant motion control with time delay estimation
No full text
Control of a heavy-duty robotic excavator using time delay control with integral sliding surface
No full textThe control of a robotic excavator is difficult from the standpoint of the following problems: parameter variations in mechanical structures, various nonlinearities in hydraulic actuators and disturbance due to the Contact with the ground. In addition, the more the size of robotic excavators increase, the more the length and mass of excavator's links, the more the parameters of a heavy-duty excavator vary. A time-delay control with switching action (TDCSA) using an integral sliding surface is proposed in this paper for the control of a 21-ton robotic excavator. Through analysis and experiments, we show that using an integral sliding surface for the switching action of TDCSA is better than using a PD-type sliding surface. The proposed controller is applied to straight-line motions of a 21-ton robotic excavator with a speed level at which skillful operators work, Experiments. which were designed for surfaces with various inclinations and over broad ranges of joint motions, show that the proposed controller exhibits good performance. (C) 2002 Elsevier Science Ltd. All rights reserved
Control of a heavy-duty robotic excavator using Time Delay Control with Switching Action with integral sliding surface
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