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  • J Abraham, P Abreu, M Aglietta, C Aguirre, D Allard, I Allekotte +439 others
  • 2007
Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrated a correlation between the arrival directions of cosmic rays with energy above 6 x 10(19) electron volts and the positions of active galactic nuclei (AGN) lying within approximately 75 megaparsecs. We rejected the hypothesis of an isotropic distribution of these(More)
The paper exposes some of the potential of a recently introduced backstepping transformation for linear uncertain time-delay systems to address the classic problems of equilibrium regulation under partial measurements, disturbance rejection, parameter or delay adaptation. For each of these problems, an implementable control strategy is proposed. It is(More)
— In this paper, we study the equilibrium regulation of potentially unstable linear systems with an unknown input time-delay and unknown parameters in the plant. We extend recent results from the literature where such systems are treated using a backstepping approach applied to a distributed parameters system representation of the delay. We develop a local(More)
— At the light of a simple tutorial example, this paper discusses the merits of a recently introduced technique to control a class of systems with a delay depending on the past values of the control variables. The relations of the proposed technique with previous works from the literature on predictor-based controllers are discussed. The treated example is(More)
In this paper, we consider periodic linear systems driven by T 0-periodic signals that we desire to reconstruct. The systems under consideration are of the form ˙ x = A(t)x + A 0 (t)w(t), y = C(t)x, x ∈ R n , w ∈ R m , y ∈ R p , (m p n) where A(t), A 0 (t), and C(t) are T 0-periodic matrices. The period T 0 is known. The T 0-periodic input signal w(t) is(More)
At the light of a simple tutorial example, this paper discusses the merits of a recently introduced technique to control a class of systems with a delay depending on the past values of the control variables. The convergence proof of the proposed control strategy is obtained by a boundedness analysis of a class of delay differential equation, inspired by the(More)
In this paper, we address the problem of air path variables estimation for an HCCI engine. Two observers are proposed. Both rely on physical assumptions on the combustion , but use different sensors. After proving convergence in the two cases, we carry out comparisons based on simulation results. We stress the impact of two particular additional sensors on(More)
This paper extends recent results for the literature which employ a backstepping transformation under the form of an infinite dimensional system to address robust control of time delay systems. The contribution treats the case of output feedback through a state observer, while allowing online adaptation of the delay system. A theoretical result is proven(More)
This paper studies the low-pressure burned gas recirculation in spark-ignited engines and shows, at the light of supportive experimental results, that a linear delay system permits to capture the dominant effects of the system dynamics. The modeled transport delay is defined by implicit equations stemming from first principles. This model is shown to be(More)