1,721,011 research outputs found
Some comments about linearization under sampling
No full textGiven a partially linearizable continuous-time dynamics, the aim is to find a digital control scheme which preserves this property under sampling. This leads to the introduction of some kind of a sampled normal form. Starting from such a form and considering the sampled dynamics as a system which is regularly perturbed by the sampling period δ, a digital control strategy for achieving partial linearization at a fixed order of approximation is propose
Discretization Schemes for Nonlinear Singularly Perturbed Systems
No full textThe authors study the effect of slow and fast sampling and analyze the structure of the resulting sampled models in the case of nonlinear singularly perturbed systems. Using combinatorial equalities, related to the Baker-Campbell-Hausdorff formula, discretization schemes for such systems are proposed. It is shown in the linear context that slow and fast sampling result in two structurally different discrete-time system
Quadratic Dynamic Feedback Linearization with Observer in Discrete Time
No full textThe design of nonlinear discrete-time control schemes is quite difficult to handle. This is in part due to the nonlinear action of the control generated by the composition of functions. It results that input-state and input-output behaviours are not easily characterised and that the conditions for feedback linearization under static feedback are quite restrictive as an example. In order to relax some of these conditions in the continuous-time case, discrete-time feedback linearization in an approximated meaning can be studied. A first step in this direction is to consider quadratic approximations. The interest of such approximation at the degree two was previously shown by the authors (1993); any linearly controllable nonlinear discrete-time dynamics can be linearized up to an error of order three thanks to a dynamic state feedback. In order to enlarge the applicability of the control scheme it is completed with P observer schem
About a normal "Column form" for nonlinear discrete-time perturbed control systems
No full textIt is known that discrete-time singularly perturbed (DSP) dynamics do not exhibit a unique canonical representation. A study in the linear context is developed in Naidu and Rao (1958), Naidu (1988) and Mahmoud (1982) with respect to discrete-time and sampled dynamics showing that at least three different normal forms can be assumed for representing a linear discrete time singularly perturbed system (linear DSPS). Starting from the generalization of these concepts to a nonlinear context, the present work studies the properties for the existence of a nonlinear column-form representation of a nonlinear DSP
- …
