106 research outputs found
Optimal control of wave linear repetitive processes
This paper gives new results on optimal control of the so-called wave discrete linear repetitive processes which find novel application in the modelling of physical examples. These processes have dynamics which are not restricted to the upper right quadrant of the 2D plane and hence the current control results for repetitive processes or 2D systems are not applicabl
Iterative learning fault-tolerant control for differential time-delay batch processes in finite frequency domains
This paper develops a fault-tolerant iterative learning control law for a~class of~linear time-delay differential batch processes with actuator faults using the repetitive process setting. Once the dynamics are expressed in this setting, stability analysis and control law design makes use of the generalized Kalman-Yakubovich-Popov (KYP) lemma in the form of the corresponding linear matrix inequalities (LMIs). In particular, sufficient conditions for the existence of a fault-tolerant control law are developed together with design algorithms for the associated matrices. Under the action of this control law the ILC dynamics have a monotonicity property in terms of an error sequence formed from the difference between the supplied reference trajectory and the outputs produced. An extension to robust control against structured time-varying uncertainties is also developed. Finally, a simulation based case study on the model of a~two-stage chemical reactor with delayed recycle is given to demonstrate the feasibility and effectiveness of the new designs
Unraveling the exciton binding energy and the dielectric constant in single crystal methylammonium lead tri-iodide perovskite
We have accurately determined the exciton binding energy and reduced mass of
single crystals of methylammonium lead tri-iodide using magneto-reflectivity at
very high magnetic fields. The single crystal has excellent optical properties
with a narrow line width of meV for the excitonic transitions and a 2s
transition which is clearly visible even at zero magnetic field. The exciton
binding energy of meV in the low temperature orthorhombic phase is
almost identical to the value found in polycrystalline samples, crucially
ruling out any possibility that the exciton binding energy depends on the grain
size. In the room temperature tetragonal phase, an upper limit for the exciton
binding energy of meV is estimated from the evolution of 1s-2s
splitting at high magnetic field.Comment: 5 pages, 4 figure
Multi-machine operations modelled and controlled as switched linear repetitive processes
Strong practical stability and stabilization of differential linear repetitive processes
Positive real control of two-dimensional systems: Roesser models and linear repetitive processes
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