بسم ا الرحمن الرحيمIn the name of GOD

DEVELOPMENT OF FUZZY LOGIC LQR CONTROL DEVELOPMENT OF FUZZY LOGIC LQR CONTROL INTEGRATION FOR FULL MISSION MULTISTAGE INTEGRATION FOR FULL MISSION MULTISTAGE

AERIAL REFUELING AUTOPILOTAERIAL REFUELING AUTOPILOT

By Eng. Ahmed Momtaz Hosny

School of Astronautics, Beihang UniversityBeijing, China

2008

Aerial Refueling Significance

1-Most of fighter aircrafts can’t exceed a certain range of 2000 Km and endurance of about 2 hours according to the small fuel capacity

2-To perform an air domination and stability over far territories during the military operations specially for large number of fighters

3-Providing aerial refueling autopilot for each fighter aircraft permits the tanker aircraft to supply large number of fighters in short time without any mishaps that could happen during the manual process

Introduction to Air Force Aerial Refueling MethodsFlying Boom versus Hose-and-Drogue

Main Objectives

1- Satisfying Flying Qualities standard

2- Minimizing the mission time

3- Satisfying the Tanker-Fighter safety constraints

3 Stages Aerial Refueling Autopilot

1- Init ial Stabil i ty Stage (LQR)

2- Tracking stage (LQRIFL)

3- Alignment Stage (LQR with Phase Lead compensator)

F-16 Nonlinear model

F-16 Control Channels

Aircraft l inearized model

Aircraft Trimming at Prescribed points

Model Linearization using the Jacobean matrices

)()()()()( tutBtxtAtx +=•

)()()()()( tutDtxtCty +=

)()()( txtCty =

Aircraft Lateral Dynamics in Linearized form

1-Init ial Stabil i ty Stage1-Init ial Stabil i ty Stage

LQ Formulation of the Tracker Problem

Pitch Rate Controller

Lateral – Directional Controller

PID Fuzzy Logic Controller

LQ Integrated Fuzzy Logic Controller

Flowchart of GA Functions

Optimizing Fuzzy Output Gains

Tuning of Fuzzy Sets

Comparison between LQR with and without Fuzzy PID

for Longitudinal and Lateral Motion

Up to 8% improving the (PI)

2- Tracking Stage 2- Tracking Stage

Input Commands to Receiving Aircraft

3-Alignment Stage

Plane Formation Geometry

Alignment Stage Controller

Trajectory scenario in x-y plane for both wingman and leader

(Boeing KC 767 Tanker – Boom configuration) versus (KC-130J Tanker with Hose – Drogue configuration) (case study)

Control Strategy

Final Conclusion Final Conclusion

It is clear from the present work that there is some basic requirements should be satisfied in It is clear from the present work that there is some basic requirements should be satisfied in

order to establish efficient aerial refueling autopilots such as (1- f lying qualit ies requirements, 2- order to establish efficient aerial refueling autopilots such as (1- f lying qualit ies requirements, 2-

safety and secured approaching in the final docking, 3- minimization the whole mission time safety and secured approaching in the final docking, 3- minimization the whole mission time

period) which implies that a multistage autopilot is needed for this purpose. Therefore LQR period) which implies that a multistage autopilot is needed for this purpose. Therefore LQR

technique was used to satisfy the flying qualit ies, providing control integration with fuzzy logic technique was used to satisfy the flying qualit ies, providing control integration with fuzzy logic

controller that enhance the output performance index. Applying an optimal trajectory during the controller that enhance the output performance index. Applying an optimal trajectory during the

tracking stage had a great effect in minimizing the total mission time. Using fl ight formation tracking stage had a great effect in minimizing the total mission time. Using fl ight formation

principle in last stage (alignment stage) had satisfied the required tanker geometrical constrains principle in last stage (alignment stage) had satisfied the required tanker geometrical constrains

mentioned before. Thus a multistage autopilot could be realized in such described sequence mentioned before. Thus a multistage autopilot could be realized in such described sequence

verifying the safety and security with minimizing the mission time interval that permit several verifying the safety and security with minimizing the mission time interval that permit several

aircrafts to be refueled in such an optimum time period. In this way it is possible to avoid any aircrafts to be refueled in such an optimum time period. In this way it is possible to avoid any

mishaps from the pilots during manual process.mishaps from the pilots during manual process.

Recommended Future WorkRecommended Future Work

It is recommended to apply the final multistage autopilot for a several aircrafts or a complete It is recommended to apply the final multistage autopilot for a several aircrafts or a complete

squadron to optimize the air refueling process time for a number of aircrafts so that decrease squadron to optimize the air refueling process time for a number of aircrafts so that decrease

the time required for the tanker aircraft to stay in the air especially in the operations time. the time required for the tanker aircraft to stay in the air especially in the operations time.

Consequently reducing the time needed for the fighter aircrafts to be refueled thus decreasing Consequently reducing the time needed for the fighter aircrafts to be refueled thus decreasing

the time to be exposed to any aggressors. This will require also different guidance laws the time to be exposed to any aggressors. This will require also different guidance laws

according to the aircraft posit ion with central controller installed in the tanker aircraft.according to the aircraft posit ion with central controller installed in the tanker aircraft.

Thank You