Double Loop Autopilot Design Based on Frequency Domain

2011 ◽  
Vol 301-303 ◽  
pp. 1724-1729
Author(s):  
Mei Sa Pang ◽  
Deng Hua Li ◽  
Jun Fang Fan ◽  
Xue Fei Li
Keyword(s):  
System Design ◽  
Frequency Domain ◽  
Static Stability ◽  
Double Loop ◽  
Guidance And Control ◽  
Control Gain ◽  
Aerodynamic Parameters ◽  
The Stability ◽  
And Control ◽  
Frequency Domain Approach

The static stability of missile pitching movement is one of the important performances in guidance and control systems. In this paper, a method which consists of the single and double loop longitudinal autopilot using frequency domain approach is proposed to solve the problem efficiently. Single-loop autopilot is used to simplify the system design when the missile is highly static stable; the double-loop autopilot is employed to stabilize the system and improve frequency performance when the missile is static stable or static unstable. Control gain of the system is determined by aerodynamic parameters and frequency domain indexes. The simulation result shows that double-loop autopilot based on frequency domain simplified the system design and improved the stability and robustness of missile system.

Some Stability and Control Aspects of Airframe/Propulsion System Interactions on the YF-12 Airplane

1974 ◽  
Vol 96 (3) ◽  
pp. 820-826 ◽  
Author(s):  
D. T. Berry ◽  
G. B. Gilyard
Keyword(s):  
Static Stability ◽  
Propulsion System ◽  
Jet Propulsion ◽  
Stability And Control ◽  
The Stability ◽  
And Control ◽  
Large Aircraft

Airframe/propulsion system interactions can strongly affect the stability and control of supersonic cruise aircraft. These interactions generate forces and moments similar in magnitude to those produced by the aerodynamic controls, and can cause significant changes in vehicle damping and static stability. This in turn can lead to large aircraft excursions or high pilot workload, or both. For optimum integration of an airframe and its jet propulsion system, these phenomena may have to be taken into account.

Adaptive integrated guidance and control for impact angle constrained interception with actuator saturation

2019 ◽  
Vol 123 (1267) ◽  
pp. 1437-1453
Author(s):  
X. L. Ai ◽  
Y. C. Shen ◽  
L. L. Wang
Keyword(s):  
Actuator Saturation ◽  
Fixed Time ◽  
Impact Angle ◽  
Guidance And Control ◽  
Inherent Problem ◽  
Saturation Constraint ◽  
Integrated Guidance And Control ◽  
The Stability ◽  
And Control ◽  
Derivatives Of

ABSTRACTThis paper considers the integrated guidance and control (IGC) problem for impact angle constrained interception against manoeuvring targets with actuator saturation constraint. Based on the backstepping technique, an adaptive IGC law is presented to address this problem, where a fixed-time differentiator is proposed to estimate the derivatives of virtual control inputs to avoid the inherent problem of “explosion of complexity” suffered by the typical backstepping. Furthermore, an auxiliary first-order filter is introduced into the IGC law to cope with the actuator saturation constraint. The stability of the closed-loop system is strictly proved. Finally, the superiority of the proposed IGC law is verified by comparison simulations.

Data Processing in Bifurcation Analysis of Maps with Time-Delays in the Frequency Domain

2014 ◽  
Vol 685 ◽  
pp. 634-637
Author(s):  
Li Zeng ◽  
Jun Wei Wang
Keyword(s):  
Data Processing ◽  
Frequency Domain ◽  
Time Delays ◽  
Period Doubling ◽  
Feedback Systems ◽  
Bifurcation Solution ◽  
Nonlinear Maps ◽  
The Stability ◽  
Frequency Domain Approach ◽  
Period Doubling Bifurcations

A unified frequency-domain approach to analyze the NS (Neimark-Sacker) bifurcations and the period-doubling bifurcations of nonlinear maps with time-delays in the linear feed-forward term is presented. The technique relies on the HBA (harmonic balance approximation, a very important method in data processing ) and feedback systems theory. The expressions of the bifurcation solution and the stability are derived.

STABILITY AND HOPF BIFURCATION ON A TWO-NEURON SYSTEM WITH TIME DELAY IN THE FREQUENCY DOMAIN

2007 ◽  
Vol 17 (04) ◽  
pp. 1355-1366 ◽  
Author(s):  
WENWU YU ◽  
JINDE CAO
Keyword(s):  
Hopf Bifurcation ◽  
Time Delay ◽  
Frequency Domain ◽  
Harmonic Balance ◽  
Neuron System ◽  
Bifurcation Theorem ◽  
Nyquist Criterion ◽  
The Stability ◽  
Frequency Domain Approach ◽  
System With Time Delay

In this paper, a general two-neuron model with time delay is considered, where the time delay is regarded as a parameter. It is found that Hopf bifurcation occurs when this delay passes through a sequence of critical value. By analyzing the characteristic equation and using the frequency domain approach, the existence of Hopf bifurcation is determined. The stability of bifurcating periodic solutions are determined by the harmonic balance approach, Nyquist criterion and the graphic Hopf bifurcation theorem. Numerical results are given to justify the theoretical analysis.

Estimation of Lateral/Directional Static Stability Characteristics of a Turboprop Aircraft at one Engine Inoperative Condition

2016 ◽  
Vol 842 ◽  
pp. 208-216 ◽  
Author(s):  
Ratna Ayu Wandini ◽  
Taufiq Mulyanto ◽  
Hari Muhammad
Keyword(s):  
Short Distance ◽  
Fuel Efficiency ◽  
Aircraft Design ◽  
Static Stability ◽  
Slip Angle ◽  
High Fuel Efficiency ◽  
Stability And Control ◽  
Conceptual Design Phase ◽  
The Stability ◽  
And Control

Twin engines turboprop aircraft provides the most beneficial solution to meet the needs of short distance flight due to high fuel efficiency [1]. One of the emergency conditions which has to be considered for this type of the aircraft when one engine is out operating or one engine inoperative because it involves the safety of flight. Furthermore, a safe flight with one engine inoperative is regulated by FAR/CASR Part 25 and has to be complied during certification .Stability and control characteristics of a turboprop aircraft will change significantly if one engine inoperative condition occurs during cruise phase. The rudder and/or aileron deflections to counter the yawing and rolling moments due to the thrust of the operating engine must satisfy. Recognizing the importance of that consideration, this research will estimate the stability and control characteristics of lateral/directional in one engine inoperative condition on new turboprop 80-pax aircraft design concept.This paper presents procedures for estimating the lateral/directional static stability characteristics of a 80-pax turboprop aircraft during the conceptual design phase. The size of the rudder and aileron have to be iterated to fullfil the requirements at a condition when one engine is not operative. The rudder and the aileron deflections are estimated as functions of airspeed, roll angle, side slip angle and thrust setting. It will be shown in this paper that the required rudder deflection as well as aileron deflection can satisfy to balance the forces and moments due to asymmetrical thrust condition and the minimum control speed of the aircraft can be maintained as well.

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