![]() Load disturbance and, in each case, the proposed scheme shows a Time, integral absolute error and integral-of-time-multiplied absoluteĮrror, in addition to the responses due to step set-point change and Several performance measures such as peak overshoot, settling time, rise Performances of the proposed self-tuning FLCs areĬompared with those of their corresponding conventional FLCs in terms of Where even the well known Ziegler-Nichols tuned conventional PI or PIDĬontrollers fail to provide an acceptable performance due to excessively ![]() Nonlinear second-order processes including a marginally stable system To conduct simulation analysis for a wide range of different linear and Proposed self-tuning technique is applied to both PI- and PD-type FLCs Using the most natural and unbiased membership functions (MFs). The rule-base for tuning the output SF is defined onĮrror (e) and change of error (Δe) of the controlled variable Is adjusted online by fuzzy rules according to the current trend of theĬontrolled process. Proposes a simple but robust model independent self-tuning schemeįor fuzzy logic controllers (FLCs). Finally, the simulation results are conducted. The fuzzy-logic-based CLOS guidance law is proposed. Then a flight simulation model is developed to obtain the flight trajectory of the missile. First, the mathematical model of overall system is derived. For this reason, which can be summarized as complex and imprecise mathematical model for the system and uncertainties in thrust and imprecise aerodynamic coefficient calculation, we use fuzzy logic controller for early period. Which usually require knowing the precise model. This feature notifies the advantages of fuzzy-logic-based CLOS guidance law over conventional guidance law. The mathematical models of the missile and target are not necessary known. In this paper, a typical anti-tank missile system is considered. The guidance computer compares the two sets of tracking data (for target and missile) and concerns the appropriate corrections (guidance commands) according to the employed guidance method to the missile during its flight through either wire link or remote link. A radar or telescope or TV camera based on the parent platform (ground, ship or vehicle) tracks the target and the missile to yield tracking data to be sent to guidance computer. In a command guidance system an operator or a computer at the control point solves the mission of interception on the basis of obtained coordinates for both the target and missile and forms the command, according to the utilized or specified guidance method, for the control system on the missile, which changes its spatial position. INTRODUCTION The instantaneous position and parameters of target flight are estimated upon which guidance or command signals are computed and applied to the missile servo system (autopilot) to correct its flight for intercepting the target with high accuracy and high kill probability. The achieved results proved that it is possible to have successful flight missions within 10% uncertainties in aerodynamic coefficients calculation and 15% in the thrust value via the designed controllers. ![]() The comparison also includes the result gained after applying noise to both controllers. The comparison include trajectory and flight angle within ranges of uncertainty in thrust and aerodynamic variation. Simulation results between conventional and designed fuzzy logic controller is accomplished. In this paper a comparison using a code written with Borland c++ is utilized for soft implementation for different controllers. ![]() It purposes to minimize the terminal miss-distance at the end of flight. The rest of the missile flight is achieved via conventional controller until target hitting. The designed second fuzzy controller starts after ∆t 1 and lasts for about ∆t 2, which, corresponds to the time required for reasonable altitude down to a low safe height that permits successful mission fulfillment without ground impact. The main goal of the first fuzzy controller is to bring down the missile flight angle from its initial launch value to near zero value in the minimum possible time. At this time the flight angle almost varies between 0 and 2 degree. The first one starts from the launch instant and ends after a fixed time ∆t1 which corresponds to time required to ensure that the missile get-together to the line of sight as quickly as possible. The controller design is divided into two intervals. The main sources of uncertainties are the thrust force and aerodynamic coefficients of the system, which escort to ill-conditional system. The system under control is antitank missile plant. In this paper a fuzzy-logic-based command to Line-Of-Sight (CLOS) controller is developed to avoid the uncertainties of the missile flight parameters during the early flight phase. ![]()
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