Nonlinear Receding-Horizon Control of Rigid Link Robot Manipulators

The approximate nonlinear receding-horizon control law is used to treat the trajectory tracking control problem of rigid link robot manipulators. The derived nonlinear predictive law uses a quadratic performance index of the predicted tracking error and the predicted control effort. A key feature of this control law is that, for their implementation, there is no need to perform an online optimization, and asymptotic tracking of smooth reference trajectories is guaranteed. It is shown that this controller achieves the positions tracking objectives via link position measurements. The stability convergence of the output tracking error to the origin is proved. To enhance the robustness of the closed loop system with respect to payload uncertainties and viscous friction, an integral action is introduced in the loop. A nonlinear observer is used to estimate velocity. Simulation results for a two-link rigid robot are performed to validate the performance of the proposed controller. Keywords: receding-horizon control, nonlinear observer, robot manipulators, integral action, robustness

La reformulation syntaxique dans les questions partielles en français

This article addresses the question of wh- questions French and the link betweensyntax and pragmatics in this language. French, contrary to all Germanic and most Romance languages, does not use pitch accent to indicate focus domains, but rather a combination of prosodic phrasing and syntactic reformulation. Following a brief discussion of the historical reasons for this situation, the paper examines data from five corpora of oral and written contemporary French and draws up a list of functional properties for each of the four basic wh-question forms. A formal analysis is provided, based on the relationship between ground and focus in wh-questions, and the theory of wh-doubling developed for Northern Italian dialects by Poletto & Pollock (2004, 2006). In this analysis two distinct operator positions are available in French, as in other Romance languages: a higher, disjunction operator position, and a lower, restriction operator position. French exploits both positions, alternating between syntactic forms depending on how the question fits into the thematic development of the context

Wh-questions in French and English

As opposed to English, French wh-questions can take a wide variety of forms. I identify four basic patterns: (a) wh- in situ: Vous êtes allés où?; (b) wh- raised, verb in situ: Où vous êtes allés?; (c) est-ce que insertion: Où est-ce que vous êtes allés?; (d) subject-clitic inversion: Où êtes-vous allés?, and argue that these are in fact ‘allo-questions’. Based on a review of historical factors, as well as on recent corpus studies, I show that each of the four question types corresponds to a distinct pragmatic function and compare French and English usage. Finally, wh- in situ constructions are formally analysed as a covert form of multiple wh-question, using an unselective binding mechanism

Alien Registration- Boucher, Leo P. (Madawaska, Aroostook County)

https://digitalmaine.com/alien_docs/35209/thumbnail.jp

Elementary Excitations in Quantum Antiferromagnetic Chains: Dyons, Spinons and Breathers

Considering experimental results obtained on three prototype compounds, TMMC, CsCoCl3 (or CsCoBr3) and Cu Benzoate, we discuss the importance of non-linear excitations in the physics of quantum (and classical) antiferromagnetic spin chains.Comment: Invited at the International Symposium on Cooperative Phenomena of Assembled Metal Complexes, November 15-17, 2001, Osaka, Japa

Alien Registration- Boucher, Joseph P. (Saint Francis, Aroostook County)

https://digitalmaine.com/alien_docs/32450/thumbnail.jp