The global existence of nonlinear observers with linear error dynamics: A topological point of view

2006 ◽  
Vol 55 (10) ◽  
pp. 849-858 ◽  
Author(s):  
MingQing Xiao
Author(s):  
So-Ryeok Oh ◽  
Sunil K. Agrawal

Cable-suspended robots are structurally similar to parallel actuated robots but with the fundamental difference that cables can only pull the end-effector but not push it. From a scientific point of view, this feature makes feedback control of cable-suspended robots lot more challenging than their counterpart parallel actuated robot. In this paper, we look into control design for a non-redundant cable-suspended robot under positive input constraints. The design is based on feedback linearization controllers augmented with reference signal management. Reference signal management operates in accordance with the receding horizon strategy, by generating admissible reference signals which makes system not to violate the input constraints. An important issue in implementing predictive horizon algorithm for nonlinear systems is to predict the system behavior in a computationally efficient way. We show that feedback linearization controllers with reference signal management can offer an efficient way to predict the system’s future states, using the error dynamics of inner feedback loop. Finally, the effectiveness of the proposed method is illustrated by numerical simulation and laboratory experiments on a six degree-of-freedom suspended cable robot.


1985 ◽  
Vol 23 (2) ◽  
pp. 197-216 ◽  
Author(s):  
Arthur J. Krener ◽  
Witold Respondek

1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.


1984 ◽  
Vol 75 ◽  
pp. 331-337
Author(s):  
Richard Greenberg

ABSTRACTThe mechanism by which a shepherd satellite exerts a confining torque on a ring is considered from the point of view of a single ring particle. It is still not clear how one might most meaningfully include damping effects and other collisional processes into this type of approach to the problem.


Author(s):  
A. Baronnet ◽  
M. Amouric

The origin of mica polytypes has long been a challenging problem for crystal- lographers, mineralogists and petrologists. From the petrological point of view, interest in this field arose from the potential use of layer stacking data to furnish further informations about equilibrium and/or kinetic conditions prevailing during the crystallization of the widespread mica-bearing rocks. From the compilation of previous experimental works dealing with the occurrence domains of the various mica "polymorphs" (1Mr, 1M, 2M1, 2M2 and 3T) within water-pressure vs temperature fields, it became clear that most of these modifications should be considered as metastable for a fixed mica species. Furthermore, the natural occurrence of long-period (or complex) polytypes could not be accounted for by phase considerations. This highlighted the need of a more detailed kinetic approach of the problem and, in particular, of the role growth mechanisms of basal faces could play in this crystallographic phenomenon.


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