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Jubien A.,CNRS Research Institute of Communication and Cybernetics of Nantes | Gautier M.,Luniversite Of Nantes Angers Le Mans | Janot A.,ONERA
2013 9th Asian Control Conference, ASCC 2013 | Year: 2013

The Usual Closed Loop Output Error (CLOE) method for dynamic parameters identification of robots has several drawbacks: slow convergence, sensitivity to initial conditions and the calculation of significant parameters is not easy-to-run. Recently a new CLOE method called as DIDIM for Direct and Inverse Identification Model needing only actual forces/torques data was validated on rigid robots. This method avoids the drawbacks of the usual CLOE method. With the DIDIM method, the optimal parameters minimize the 2-norm of the error between the actual forces/torques and the simulated ones. It is based on a closed-loop simulation of the robot using the direct dynamic model, the same structure of control-law and the same reference trajectory for both the actual robot and the simulated one. The DIDIM method simplifies dramatically the non-linear Least Squares problem by using the Inverse Dynamic Model in order to obtain an analytical expression of the simulated forces/torques which are linear in the parameters. This explains why the DIDIM method has a fast convergence. In this paper, the DIDIM method is compared with the usual CLOE method which uses the actual positions as output. Experiments are performed on a 6 degrees of freedom robot Stäubli TX40. © 2013 IEEE.


Lelievre B.,Luniversite Of Nantes Angers Le Mans | Lelievre B.,University of Angers | Legras P.,Luniversite Of Nantes Angers Le Mans | Legras P.,University of Angers | And 8 more authors.
Journal of Pharmacology and Experimental Therapeutics | Year: 2013

Scedosporium apiospermum is a soil fungus which can cause severe and often fatal cerebral infections in both immunocompetent patients in the event of near drowning and immunosuppressed patients such as lung transplant recipients. Because of the low susceptibility of this fungus to antifungal drugs, and the low permeability of the blood-brain barrier (BBB), therapeutic drug monitoring is necessary to reach an effective tissue concentration with limited side effects. Indeed, diffusion of the drug in the brain is dependent on several parameters, such as the integrity of the BBB and the activity of efflux pumps. To evaluate drug diffusion, two experimental models were developed in immunocompetent and immunosuppressed rats. Inocula were administered via the penile vein and a clinical scale (0-9) was established, based on weight and clinical and neurologic signs evaluated by the tail suspension test. Cerebral involvement was confirmed by magnetic resonance imaging and histologic examination of brain sections after hematoxylin-eosin-safran or silver staining. Voriconazole or posaconazole was given to the rats at doses ranging from 10 to 75 mg/kg/day via i.v. or oral routes, respectively. Whatever the immune status, the effective doses (defined by a doubling of the survival time and the absence of neurologic sequelae) were 30 mg/kg/day for voriconazole and 50 mg/kg/day for posaconazole. Overall, the results demonstrated that these models may constitute valuable tools for the performance of pharmacokinetic and pharmacodynamic studies for pharmacokinetic-pharmacodynamic modeling. Copyright © 2013 by The American Society for Pharmacology and Experimental Therapeutics.

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