1,721,042 research outputs found
TOWARD BYNARY RHODIUM NITRIDES: SYNTHESIS OF HIGH NUCLEARITY CARBONYL CLUSTERS CONTAINING SEVERAL INTERSTITIAL NITROGEN ATOMS
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Real-Time Inverse Dynamics Control of Parallel Manipulators Using General-Purpose Multibody Software
No full textThis work deals with the problem of computing the inverse dynamics of complex constrained mechanical systems for real-time control applications. The main goal is the control of robotic systems using model-based schemes in which the inverse model itself is obtained using a general purpose multibody software, exploiting the redundant coordinate formalism. The resulting control scheme is essentially equivalent to a classical computed torque control, commonly used in robotics applications. This work proposes to use modern general-purpose multibody software to compute the inverse dynamics of complex rigid
mechanisms in an efficient way, so that it suits the requirements of realistic real-time applications as well. This task can be very difficult, since it involves a higher number of equations than the relative coordinates approach. The latter is believed to be less general, and may suffer from topology limitations. The use of specialized linear algebra solvers makes this kind of control algorithms usable in real-time for mechanism models of realistic complexity. Numerical results from the simulation of practical applications are presented, consisting in a “delta” robot and a bio-mimetic 11 degrees of freedom manipulator controlled using the same software and the same algorithm
Deactivation of a [PPN][Rh(CO)(4)]-based catalytic system [PPN+ = (PPh3)(2)N+]. The first decomposition reaction of PPN+ and the formation of [Rh10P(CO)(22)](3-)
No full textMEMS Integrated Electro-Fluid-Elastic Modelling for Aerospace Applications
No full textMEMS physics is characterized by multi-fields interactions. In this paper, a fully integrated methodology is proposed for dynamical analysis of electro-fluid-elastic systems, typical of MEMS-based microresonators and microswitches. Finite Elements/Volumes Method is used to solve field equations. These are coupled by an opportune procedure of interface between domains, resulting in a nonlinear algebraic differential system of equations describing the system. This is directly integrated in time, becoming fully algebraic, and solved by a Newton technique. Full Jacobian matrix computation results in a very hard task. Analytical block approximation for Jacobian matrix is proposed. Model is validated comparing results with commercial codes and with published data, showing good agreement, high convergence properties and reduced computational efforts
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