Nonlinear model of open-loop mode capacitive micro-accelerometer

Author(s):  
Qiang Dai ◽  
Xiufen Shi ◽  
Chun Han ◽  
Mohua Yang
1996 ◽  
Vol 06 (06) ◽  
pp. 593-598
Author(s):  
FRANK HUNG-FAT LEUNG ◽  
LIK-KIN WONG ◽  
PETER KWONG-SHUN TAM

A large-signal nonlinear model for zero-current-switch quasi-resonant buck converters is presented. The derivation is simple and the results are accurate even for large-signal operation. Such a model can be used for the analysis and simulation of the switching converter, no matter in open-loop or in closed-loop, with fast speed. The condition for zero-current switching can also be identified from this model.


Author(s):  
Barathram Ramkumar ◽  
D. Subbaram Naidu

Cancer chemotherapy is the treatment of cancer using drugs that kill the cancer cells, when the drugs are administered either orally or through veins. The drugs are delivered according to a schedule so that a particular dosage of drug level is maintained in the body. The disadvantage of these drugs is that they not only kill the cancer cells but also kill the normal healthy cells. The role of optimal control in chemotherapy is to maintain an optimum amount of drug level in the body so that only cancer cells are killed and hence the effect of drug on the healthy cells is minimized. Three different mathematical models for cancer growth are considered: log-kill hypothesis, Norton-simon model, and Emax model. Two different cost functions are considered for constrained and unconstrained optimal control, respectively. An open loop optimal control strategy has been reported in the literature. In this paper, a closed-loop optimal control strategy is addressed using all the three models and for both the cases of constrained and unconstrained drug delivery. For the unconstrained case the original nonlinear model has been linearized and the closed loop design is obtained by using matrix Riccati solutions. On the other hand, for the constrained case the original nonlinear model has been used to obtain closed loop optimal control using bang-bang strategy. Final simulation results show the advantages of closed loop implementation in terms of simpler and elegant controller design and incorporating the effect of current state variations.


2021 ◽  
Vol 54 (4) ◽  
pp. 623-631
Author(s):  
Bouir Abdesselam ◽  
Benoudjafer Cherif ◽  
Boughazi Othmane

In order to control output powers generated by doubly fed induction generator (DFIG) used in wind application (WA) many previous studies, mainly based on flux orientation control (FOC) and neglecting resistance to get a simple model of DFIG with decoupled axis. However, this control strategy requires several hypotheses: low and stability of grid voltage in order to orientated the statoric flux, high power of generator to neglecting statoric resistance. As a result that may not be present in realty due to direct connection between stator and the grid In addition to the presence of resistance, whatever the power of the generator, therefore the DFIG represents a complex model and required a nonlinear control without previous approaches closer to reality to respond highly against DFIG nonlinear model, this is the first paper presents a novel strategy to control nonlinear model of DFIG based on substitution method to solving (d,q) coupled axes without flux orientation and neglecting resistance (FOANR) and also does not take into account stability of grid voltage, for produce required reference active and reactive power by controlling the voltage of rotor side converter (RSC), using classical proportional-integral (PI) controller in a non-linear synthesis form by three methods :direct control (D) and indirect open loop (IOL) and indirect with power loop (IWPL),we compared three controls and check their performance towards the real model of DFIG to verify our control and proving its effectiveness without previous approaches. Finally, the simulation results of the studied controls are presented, analyzed and compared.in terms of power reference tracking, robustness to the parametric variation and the ability to respond to sudden wind speed variation.


2016 ◽  
Vol 6 (1) ◽  
pp. 178-186
Author(s):  
Vu Trieu Minh

AbstractThis paper develops the nonlinear model predictive control (NMPC) algorithm to control autonomous robots tracking feasible paths generated directly from the nonlinear dynamic equations.NMPC algorithm can secure the stability of this dynamic system by imposing additional conditions on the open loop NMPC regulator. The NMPC algorithm maintains a terminal constrained region to the origin and thus, guarantees the stability of the nonlinear system. Simulations show that the NMPC algorithm can minimize the path tracking errors and control the autonomous robots tracking exactly on the feasible paths subject to the system’s physical constraints.


1989 ◽  
Vol 49 (1) ◽  
pp. 161-168
Author(s):  
A. Bülent Özgü Ler ◽  
Vasfi Eldem
Keyword(s):  

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