By taking Laplace transformation of (8), the transfer function of the FOPD can be obtained by
The phase and the gain of the FOPD could be further given as
As for the outer-loop controller, namely, the FOPD, [k.sub.p], [k.sub.d], and [lambda] are the three main parameters that determine the performances of the control system.
The parameters of the FOPD are solved according to (17)-(20) by means of the nonlinear solving module of the software MATLAB.
To investigate the disturbance rejection capacity of the proposed DOB based FOPD control strategy, step response with sinusoid disturbance is investigated where the frequency and amplitude of the predefined disturbance are 1Hz and 0.05, respectively.
The results demonstrate the efficiency of the developed FOPD controller for the nominal control system.
The tracking error of the DOB based FOPD control system in the steady state is about 0.5 mil which is about 26.32% of that of the control system without the DOB.
During his visit he secured unprecedented strategic support by nearly two dozen heads of states and governments from the platform of FoPD
, was greeted with the passage of the Kerry Lugar Bill, addressed the UN General Assembly, secured commitment from Italian Prime Minister to personally lead high level business delegation to Pakistan, called on Pope Benedict XVI, addressed the London International Institute of Strategic Studies and held a series of political and economic meetings that prepared ground for launching new initiatives for the country's economic revival.