FUZZY LOGIC APPROACH TO AIRPLANE PRECISION INSTRUMENT APPROACH AND LANDING Vahed Tavakoli Zadeh B.S., Civil Aviation Technology College Tehran, Iran 2001 B.S., Embry Riddle Aeronautical University, 2005 THESIS Submitted in partial satisfaction of The requirements for the degree of MASTER OF SCIENCE in MECHANICAL ENGINEERING at CALIFORNIA STATE UNIVERSITY, SACRAMENTO FALL 2011 FUZZY LOGIC APPROACH TO AIRPLANE PRECISION INSTRUMENT APPROACH AND LANDING A Thesis by Vahed Tavakoli Zadeh Approved by: __________________________________, Committee Chair Akihiko Kumagai, Ph. D. __________________________________, Second Reader Tien-I Liu, Ph. D. ____________________________ Date ii Student: Vahed Tavakoli Zadeh I certify that this student has met the requirements for format contained in the University format manual, and that this thesis is suitable for shelving in the Library and credit is to be awarded for the thesis. __________________________, Graduate Coordinator ___________________ Akihiko Kumagai, Ph. D. Date Department of Mechanical Engineering iii Abstract Of FUZZY LOGIC APPROACH TO AIRPLANE PRECISION INSTRUMENT APPROACH AND LANDING By Vahed Tavakoli Zadeh In the precision instrument approach and landing of an airplane where the uncertainty is very frequent due to the high sensitivity of the activity to many factors that influence the behavior of the pilots, Fuzzy logic can be used to produce estimates which take into account the vagueness of the flight environment. In this situation, an important decision about the approach and landing of the airplane under Instrument meteorological conditions is based on these conditions. Instrument meteorological conditions (IMC) describes weather conditions that require pilots to fly primarily by reference to instruments, and therefore under Instrument Flight Rules (IFR), rather than by outside visual. Typically, instrument meteorological conditions are defined as bad visibility and low ceiling. In this thesis an analysis of the inputs under fuzzy logic approach is considered for a landing of airplane in Instrument meteorological conditions. The success rate of landing is investigated, when the visibility, pilot experience and air speed are given by a fuzzy function. The main advantages of this approach are then discussed. Precision instrument approach and landing simulations are used and the performance of the fuzzy based system is evaluated with fuzzy logic toolbox under MATLAB’s Simulation Block iv Set which provides a complete set of tools for evaluating the success rate of landing under the given inputs. Around 100 approach and landings are simulated using Microsoft Flight Simulator. All these flight simulation cases were applied to train the proposed fuzzy logic engine to calculate the success rate of landing. After the proposed fuzzy logic engine has been fully developed, it has been evaluated and then the evaluated results from the proposed fuzzy logic engine compared with flight simulation data collected for evaluation. Comparison of the results from the developed fuzzy based system and flight simulation results show that the proposed fuzzy engine can successfully predict the success rate of landing under the given inputs. _______________________, Committee Chair Akihiko Kumagai, Ph. D. _______________________ Date v ACKNOWLEDGMENTS The author would like to acknowledge and thank: the support of Department of Mechanical Engineering at California State University, Sacramento for providing the computational resources, and Dr. Akihiko Kumagai and Dr. Tien-I Liu for their technical expertise and guidance. Lastly, I would like to thank Dr Holl, Department Chair, for the help to complete my Master in Mechanical Engineering. Finally, I would like to thank my wife, Abbey, for her love, support, and encouragement that has enabled me to get this far. vi TABLE OF CONTENTS Page Acknowledgments …………………………………………………………...………………...vi List of Tables…………………………………………..………………………………………ix List of Figures ………………………………………………………………………………....x Chapter 1. INTRODUCTION …………………………. ……….…………………………………......1 2. DESCRIPTION OF THE PROPOSED FUZZY LOGIC …………………………………..5 2.1 Introduction …………………………………………………….……………………...5 2.2 The Proposed Fuzzy Inference System…….……................…………………………..9 2.2.1 Overview of Fuzzy Inference Process ……………………..……………………9 2.2.2 Step 1. Fuzzify Inputs ……………………………………………………….…10 2.2.3 Step 2. Apply Fuzzy Operator ……………………………………….………...10 2.2.4 Step 3. Apply Implication Method …………………………………….……....11 2.2.5 Step 4. Aggregate All Outputs …………………………………………………12 2.2.6 Step 5. Defuzzify ………………………………………………………………13 3. THE FIS MODLING AND SIMULATIONS ……………….……………………………14 3.1 Introduction …………………………………………………………………………..14 3.2 Modeling ……………………………………………………………………………...14 3.3 Loading Data ………………………………………………………………………....16 3.4 ANFIS Training ………………………………………………………………………20 3.5 The FIS Editor ………………………………………………………………………..22 3.6 The Membership Function Editor …………………………….……………………...23 vii 3.7 The Rule Editor ………………………………………………………………………26 3.8 The Rule Viewer ……………………………………………….……………………..27 3.9 The Surface Viewer …………………………………………….…………………….29 3.10 The FIS Evaluation ………………………………….………………………………32 4. CONCLUSION AND FURTHER STUDY ………………………………………………35 Appendix A The Matlab Structure Syntax.….………………………………………………...37 Appendix B Membership Function Plots and Surface Plot.………...………………………...41 Appendix C Flight Simulation Results…………………………………………….………….45 References ……………………………………………………………………………….……49 viii LIST OF TABLES Page 1. Table 1 The FIS and Simulation Results ……………..…………….…...……………....33 ix LIST OF FIGURES Page 1. Figure 1.1 Flight Simulation with MS Flight Simulator………………………………......3 2. Figure 2.1 A Graphical Example Of An Input-Output Map ……..…...………………......5 3. Figure 2.2 Roadmap For The Fuzzy Inference Process ……………..……………......…..6 4. Figure 2.3 Visibility Membership Function Curve ………………………………….........7 5. Figure 2.4 The Proposed Fuzzy Inference System ………..……………………...…. …..8 6. Figure 2.5 The Basic Structure of the Fuzzy Inference System ……………....……….....9 7. Figure 2.6 Visibility Input ……………………………………………………...………..10 8. Figure 2.7 Apply Fuzzy Operator AND ……………………………...……………........11 9. Figure 2.8 Apply Implication Method ………………………………...…………….......11 10. Figure 2.9 Aggregate All Outputs ……………………………………...………………..12 11. Figure 2.10 Defuzzify the Aggregated Output ………………………………………. ...13 12. Figure 3.1 The ANFIS Editor GUI Window …………………………………...……….15 13. Figure 3.2 Loading the Training Data Set …………………………………………..…..16 14. Figure 3.3 Loading the Checking Data Set ………………...……………………………17 15. Figure 3.4 The Model FIS Structure ………………………...…………………………..19 16. Figure 3.5 The Checking Error and Training Plot …………...………………………….20 17. Figure 3.6 Testing the Training Data against the FIS Output …………...………………21 18. Figure 3.7 The FIS Editor ………………………………………………..……………...22 19. Figure 3.8 Visibility Membership Functions ………………………………. ….……….23 20. Figure 3.9 Pilot Experience Membership Functions …………………………………….24 21. Figure 3.10 Air Speed Membership Function …………………………………………...25 x 22. Figure 3.11 The Proposed FIS Rule Viewer ………………………………...…………..26 23. Figure 3.12 The Proposed Rule Viewer ……………………………………...………….28 24. Figure 3.13 Visibility VS Pilot Experience ………….……………………….…………29 25. Figure 3.14 Air Speed VS Pilot Experience ………………………………………...…..30 26. Figure 3.15 Air Speed VS Visibility ………………………………………………..…..31 27. Figure 3.16 Out Put Response Comparison of Simulation and FIS Result ……………..34 xi 1 Chapter 1 INTRODUCTION The purpose of this thesis is to design a fuzzy logic engine to evaluate the success rate of landing of the airplane on approach to land (final leg) under different visibility and airspeed. To train the fuzzy logic system, data were collected by simulation of 100 flight cases under different visibilities, pilot experience and air speed. Two pilots have done the flight simulations, One with 500 hours flight experience and another one with 2000 hours flight experience. In addition to 100 flight simulations applied for training the fuzzy engine, 16 flight simulation data were applied for checking and testing the system and 16 flight cases were evaluated by the created fuzzy logic engine. Chapter 2 discusses the description of the proposed fuzzy inference system. There are some inputs, like visibility and pilot experience and air speed and the output is the success rate of landing. This chapter shows how the components of the proposed fuzzy engine work. Based on the nature of fuzzy human thinking, Lofti Zadeh originated the “fuzzy logic” or “fuzzy set theory”, in 1965 [4]. Fuzzy logic deals with the problems that have fuzziness or vagueness. In fuzzy set theory based on fuzzy logic a particular object has a degree of membership in a given set that may be anywhere in the range of 0 (completely not in the set) to 1 (completely in the set) .For this reason fuzzy logic is often defined as multi-valued logic (0 to 1). 2 Chapter 3 discusses how to train the fuzzy inference system and test the fuzzy inference system under MATLAB fuzzy logic toolbox and fuzzy logic application. This toolbox relies heavily on graphical user interface (GUI) tools to help accomplish the work. After the fuzzy inference system has been fully trained. We start creating the engine to evaluate the success rate of landing under set conditions. The objective of this thesis is to build a fuzzy logic engine using to calculate the success rate of landing under different inputs (visibility, pilot experience and air speed). The thesis will conclude with the simulation results and evaluation of the proposed fuzzy inference system. Figure 1.1 shows a simulated flight done with Microsoft flight simulator under high visibility,pilt experience with 500 hours and 100knots air speed on final approach.The visibility range is from 0 to 15 Statute Miles and the air speed range is between 40 knots to 100 knots.Pilot experience is based on flight hours (A pilot with 500 hours and another pilot with 2000 hours ). 3 Figure 1.1 Flight Simulation with MS Flight Simulator When pilot is on the approach and landing phase of flight, there are many factors can affect the landing. This is the single most demanding phase of flight, and the one that carries the highest risk. One of the elements in a successful landing is the pilot experience. It is also necessary to keep up with any changes in the runway status or destination weather as the flight progresses therefore visibility is a very important element in a spectacular landing. Another element in making a spectacular landing is to fly a stabilized approach with the manufacturer’s recommended airspeed on final. In this 4 thesis 3 elements considered (visibility, pilot experience and airspeed) as the inputs for calculating the success rate of landing. There are some other important parameters which could significantly influence for successful landing. One of the important parameter is wind speed and wind direction. In all the flight simulations, wind considered to be calm. Virtually every pilot has experienced some form of illusion during the approach and landing phases of a flight. There are a variety of illusions that can create problems during the approach and landing. Human factors are other parameters affecting the landing. Due to the vagueness of the flight environment there is no flight parameter limitation. There are many other factors that can be considered for successful landing. In this thesis visibility, pilot experience and air speed are the only inputs considered for calculating the success rate of landing. Good landings are the result of good approaches with flying at a constant target airspeed, and constant target descent rate. The touchdown point should be within the first third of the runway's length. At touchdown and thereafter, the airplane should be sufficiently well centered that the centerline is between the main wheels. The touchdown should be gentle enough that the nose wheel stays in the air during touchdown and during the first 50 feet of the rollout. Other than that it will be considered to be bad or failed landing. 5 Chapter 2 DESCRIPTION OF THE PROPOSED FUZZY LOGIC 2.1 Introduction In this research with information about what the visibility, pilot experience and air speed were on the instrument precision approach and landing, the proposed fuzzy logic system can evaluate the success rate of landing. Figure 2.1 shows a graphical map of the input-output. This figure shows the success rate of landing as the output and visibility as one of the inputs. The black box between the input and the output is the proposed fuzzy engine which calculates the success rate of landing. Figure 2.1 A Graphical Example of an Input-Output Map 6 Figure 2.2 provides a roadmap for the fuzzy inference process. It shows the general description of a fuzzy system on the left and the proposed fuzzy system on the right. Based on the set of rules and interpreted inputs (visibility is interpreted as low, medium and high), the proposed fuzzy engine assigns values to the output (success rate of landing). Figure 2.2 Roadmap for the Fuzzy Inference Process 7 Figure 2.3 shows the sharp edged MF for visibility that the degree of membership is either 0 or 1 and the continuous MF for visibility with the degree of membership range from 0 to 1. Figure 2.3 Visibility Membership Function Curve 8 Figure 2.4 shows antecedent and consequent with crisp visibility inputs, pilot experience and air speed. This figure shows application of AND operator and implication operator. Figure 2.4 The Proposed Fuzzy Inference System 9 2.2 The Proposed Fuzzy Inference System 2.2.1 Overview of Fuzzy Inference Process Fuzzy inference process comprises of five parts: fuzzification of the input variables, application of the fuzzy operator (AND or OR) in the antecedent, implication from the antecedent to the consequent, aggregation of the consequents across the rules, and defuzzification. Figure 2.5 shows the basic structure of the proposed fuzzy logic system. Figure 2.5 The Basic Structure of the Fuzzy Inference System 10 2.2.2 Step 1. Fuzzify Inputs Figure 2.6 shows the process of fuzzifying the visibility. The visibility input is a crisp numerical value from 0 to 15 statue miles and the output of fuzzyfying visibility is a fuzzy degree of MF between 0 and 1. Figure 2.6 Visibility Input 2.2.3 Step 2. Apply Fuzzy Operator Figure 2.7 shows the AND operator. The three different pieces of the antecedent (visibility is good and pilot experience is high and air speed is normal) yielded the fuzzy membership values 0.8, 0.9 and 0.8 respectively. The fuzzy AND operator simply selects the minimum of the three values, 0.8. 11 Figure 2.7 Apply Fuzzy Operator AND 2.2.4 Step 3. Apply Implication Method Figure 2.8 shows the implication process after proper weighting of the rules. Figure 2.8 Apply Implication Method 12 2.2.5 Step 4. Aggregate All Outputs Figure 2.9 shows aggregation process by which the fuzzy sets that represent the outputs of each rule are combined into a single fuzzy set. Aggregation only occurs once for each output variable, just prior to the defuzzification. Figure 2.9 Aggregate All Outputs 13 2.2.6 Step 5. Defuzzify Figure 2.10 shows the defuzzification process by which the output (success rate of landing) is a single number. Figure 2.10 Defuzzify the Aggregated Output 14 Chapter 3 THE FIS MODELING AND SIMULATIONS 3.1 Introduction This chapter will discuss modeling and simulation of the proposed fuzzy inference system. This section will discuss the use of the function ANFIS and the ANFIS Editor GUI in the toolbox. These tools apply fuzzy inference techniques to data modeling. The shape of the membership functions depends on parameters, and changing these parameters change the shape of the membership function. Fuzzy Logic Toolbox applications were used to get the shape of the membership functions [3]. 3.2 Modeling To apply the proposed fuzzy inference to a system for which all the flight simulations have been done rather than choosing the parameters associated with a given membership function arbitrarily, Fuzzy Logic Toolbox neuro-adaptive learning techniques incorporated in the ANFIS command has been used. Figure 3.1 shows the ANFIS Editor window where training data and check data will be loaded. It can be seen that ANFIS Editor window consists of 4 major sections (Load data, Generate FIS, Train FIS and Test FIS). 15 Figure 3.1 The ANFIS Editor GUI Window 16 3.3 Loading Data The training data set collected from the flight simulations is used to train the proposed fuzzy system. Figure 3.2 shows the loaded training data and checking data. The training and checking data are annotated in blue as circles, and pluses respectively. Figure 3.2 Loading the Training Data Set 17 Figure 3.3 shows the loaded checking data. Checking data appears in the GUI plot as pluses superimposed on the training data. This data set will be used to train the proposed fuzzy system. Figure 3.3 Loading the Checking Data Set 18 Grid partition method is being used to initialize the FIS. The following Number of membership functions will be considered in this case; [4 2 4],[3 2 3] and [2 2 2]. All these cased will be evaluated for better performance of the FIS. Membership type will be trimf and the output membership type is constant. Figure 3.4 shows the model structure after the FIS was generated. This figure shows that there are 3 inputs (visibility, pilot experience and air speed), first input (visibility) with 4 membership functions, second input (pilot experience) with 2 membership functions and the last input (Air speed) with 4 membership functions. 19 Inputs Membership Functions Rules Figure 3.4 The Model FIS Structure Output 20 Checking Error Training Error Figure 3.5 The Checking Error and Training Error Plot 3.4 ANFIS Training The two ANFIS parameter optimization method options available for FIS training are hybrid and back propagation. To train the FIS, the back propagation method was used. Figure 3.6 shows the results of the training data against the FIS output. The training data are annotated in blue as circles, and the FIS output are annotated in red. 21 Training Data FIS Output Figure 3.6 Testing the Training Data against the FIS Output 22 3.5 The FIS Editor Figure 3.7 shows the information about a fuzzy inference system with the names of each input variable on the left and the output variable on the right. In the proposed FIS, Sugeno type inference used, with 3 inputs and 1 output. The three inputs are visibility, pilot experience and air speed. The one output is success rate of landing. Figure 3.7 The FIS Editor 23 3.6 The Membership Function Editor Figure 3.8 shows the visibility membership functions for the proposed fuzzy inference system. The visibility membership functions are interpreted as very low, low, medium and high. Figure 3.8 Visibility Membership Functions 24 Figure 3.9 shows the pilot experience membership functions for the proposed fuzzy inference system. The pilot experience membership functions are interpreted as low, and high. Figure 3.9 Pilot Experience Membership Functions 25 Figure 3.10 shows the air speed membership functions for the proposed fuzzy inference system. The air speed membership functions are interpreted as low, average, high and very high. Figure 3.10 Air Speed Membership Functions 26 3.7 The Rule Editor Figure 3.11 shows the generated rules for the proposed fuzzy logic engine. At this point, the fuzzy inference system has been completely defined, in that the variables, membership functions, and the rules necessary to calculate success rate of landing. Figure 3.11 The Proposed FIS Rule Editor 27 3.8 The Rule Viewer Figure 3.12 shows the Rule Viewer of the proposed fuzzy logic system. Each rule is a row of plots, and first column is the visibility, second column is the pilot experience and the third column is the air speed. The fourth column of plots shows the membership functions referenced by the consequent, or the then-part of each rule. This decision will depend on the input values for the system. The defuzzified output is displayed as a bold vertical line on this plot. The variables and their current values are displayed on top of the columns. Each of the characterizations of each of the variables is specified with respect to the input index line in this manner. The defuzzified output value is shown by the thick line passing through the aggregate fuzzy set. 28 Figure 3.12 The Proposed Rule Viewer 29 3.9 The Surface Viewer Figure 3.13 shows the surface view of the proposed FIS for visibility and pilot experience. This curve represents the mapping from visibility and pilot experience to success rate of landing. This figure represents the success rate of landing based on the visibility and pilot experience. It shows the success rate of landing remains slightly steady high after the visibility is high enough. Figure 3.13 Visibility VS Pilot Experience 30 Figure 3.14 shows the surface view of the proposed FIS for air speed and pilot experience. This curve represents the mapping from air speed and pilot experience to success rate of landing. This symmetrical surface shows that success rate of landing is more sensitive to the air speed. Figure 3.14 Air Speed VS Pilot Experience 31 Figure 3.15 shows the surface view of the proposed FIS for air speed and visibility. This curve represents the mapping from air speed and visibility to success rate of landing. This symmetrical surface also shows that the success rate of landing is more sensitive to the air speed. Figure 3.15 Air Speed VS Visibility 32 3.10 The FIS Evaluation In order to validate the proposed approach for the fuzzy inside instrument approach and landing several cased had been conducted based on simulated experimental data. Three inputs (visibility, pilot experience and airspeed) were used to provide the measurable inputs to the fuzzy system through the simulations. To evaluate the output of the proposed fuzzy logic system for a given input, 16 cases were evaluated. The following table shows the results from fuzzy logic system were compared with the simulated results. The presented simulation results have confirmed the ability of the proposed fuzzy logic system to calculate the success rate of landing. By comparing the FIS results and the simulated results, it can be noticed that the proposed fuzzy engine is able to accurately calculate the success rate of landing under different cases. 33 Table 1 The FIS and Simulation Results CASE # VISIBILITY PILOT AIRSPEED EXPEREINCE FIS SIMULATED RESULTS RESULTS 1 0 500 100 0.0035 0 2 1 500 90 0.0099 0 3 2 500 80 0.0121 0 4 3 500 77 0.0170 0 5 4 500 65 0.9588 1 6 5 500 62 0.9523 1 7 6 500 59 0.9347 1 8 7 500 48 0.0044 0 9 8 2000 66 0.9995 1 10 9 2000 59 09654 1 11 10 2000 56 0.9540 1 12 11 2000 53 0.8995 1 13 12 2000 49 0.0215 0 14 13 2000 46 0.0133 0 15 14 2000 43 0.0098 0 16 15 2000 40 0.0059 0 34 Output response comparison 1.2 Success rate of landing 1 0.8 0.6 FIS results 0.4 Simulated results 0.2 0 0 5 10 15 20 -0.2 Flight case Figure 3.16 Output Response Comparison of Simulated and FIS Results 35 Chapter 4 CONCLUSION AND FURTHER STUDY The current research has been carried out for developing a fuzzy logic engine to estimate the success rate of landing under the set conditions. By using a fuzzy inference system in the framework of an adaptive neuro-fuzzy inference System (ANFIS), it provides a tool which makes the success rate of landing more accurate because by ANFIS fuzzy logic, it would be possible to estimate the fuzzy inference system parameters. This method could be applied extensively to solve the engineering problems in which most of them are in some specify fuzzy conditions. The performance of the model with respect to the estimation made by evaluation and test data has been satisfactory. It was also illustrated that the fuzzy logic engine is able to calculate the success rate of landing under the assigned inputs. It is also concluded the ANFIS technique could be used as a very accurate, reliable and fast method for calculation of the success rate of landing. The methodology presented in this thesis explored and combined two concepts: Fuzzy Logic and airplane instrument approach and landing where the uncertainty is very frequent. The proposed fuzzy engine can successfully calculate the success rate of landing based on different visibility, pilot experience and air speed. This work can be further developed in the following areas: 36 By doing more flight simulations for better and more accurate results and apply human factors as an input to the fuzzy logic system which human factors are a broad field that examines the interaction between people, machines, and the environment for the purpose of improving performance and reducing errors. As aircraft became more reliable and less prone to mechanical failure, the percentage of accidents related to human factors increased. Some aspect of human factors now accounts for over 80 percent of all accidents. Pilots who have a good understanding of human factors are better equipped to plan and execute a safe and uneventful flight [1]. By changing weather conditions as another input. The safety of the flight depends upon the pilot’s ability to manage this variable. In addition to the weather conditions that might affect a VFR flight, an IFR, it is being recommended to consider the effects of other weather phenomena such as thunderstorms, turbulence, icing, fog and wind shear [1]. 37 APPENDIX A The Matlab Structure Syntax [System] Name='THE PROPOSED FIS' Type='sugeno' Version=2.0 NumInputs=3 NumOutputs=1 NumRules=32 AndMethod='prod' OrMethod='probor' ImpMethod='prod' AggMethod='max' DefuzzMethod='wtaver' [Input1] Name='VISIBILITY' Range=[0 15] NumMFs=4 MF1='VERY_LOW':'trimf',[-5 -0.0866953195682162 4.99977536353742] MF2='LOW':'trimf',[-0.00247475523808451 4.89582230292664 9.9510965722722] MF3='MEDIUM':'trimf',[5.01857521769034 9.90447138015018 14.8681033531786] MF4='HIGH':'trimf',[9.99951155119642 14.9198722966028 20] [Input2] Name='PILOT_EXPERIENCE' Range=[500 2000] 38 NumMFs=2 MF1='in2mf1':'trimf',[-1000 500 1999.99999999277] MF2='in2mf2':'trimf',[500.000000001233 2000 3500] [Input3] Name='AIR_SPEED' Range=[40 100] NumMFs=4 MF1='in3mf1':'trimf',[20 40.0822855887941 59.8978408262497] MF2='in3mf2':'trimf',[40.2203650852729 60.1983524621982 79.998830690857] MF3='in3mf3':'trimf',[60.1510956994258 80.0917240621206 99.9752927916075] MF4='in3mf4':'trimf',[79.9472637715754 99.9756462725235 120] [Output1] Name='SUCCESS_RATE_OF_LANDING' Range=[0 1] NumMFs=32 MF1='out1mf1':'constant',[0.0082081939390241] MF2='out1mf2':'constant',[0.569701574525364] MF3='out1mf3':'constant',[0.0400047904307698] MF4='out1mf4':'constant',[0.0165440923348753] MF5='out1mf5':'constant',[-0.264906080378969] MF6='out1mf6':'constant',[0.512033081547978] MF7='out1mf7':'constant',[-0.244285271708471] MF8='out1mf8':'constant',[0.0793180922669434] MF9='out1mf9':'constant',[-0.438131938839094] MF10='out1mf10':'constant',[1.18104476635337] MF11='out1mf11':'constant',[0.167113520979754] 39 MF12='out1mf12':'constant',[-0.0803868979781637] MF13='out1mf13':'constant',[-0.0478079763911111] MF14='out1mf14':'constant',[1.38817384556867] MF15='out1mf15':'constant',[0.160606314987157] MF16='out1mf16':'constant',[-0.035215328374081] MF17='out1mf17':'constant',[-0.0392689626147112] MF18='out1mf18':'constant',[1.32098913325736] MF19='out1mf19':'constant',[-0.126975761506084] MF20='out1mf20':'constant',[0.107398937311983] MF21='out1mf21':'constant',[-0.351857337467939] MF22='out1mf22':'constant',[1.27922619878734] MF23='out1mf23':'constant',[0.167575483585494] MF24='out1mf24':'constant',[-0.235623827741807] MF25='out1mf25':'constant',[-0.141197825918983] MF26='out1mf26':'constant',[0.604231529198334] MF27='out1mf27':'constant',[0.558989552061019] MF28='out1mf28':'constant',[1.23753418149047] MF29='out1mf29':'constant',[-0.155055741776899] MF30='out1mf30':'constant',[1.0919144580996] MF31='out1mf31':'constant',[0.323444348254456] MF32='out1mf32':'constant',[-0.042384497776231] [Rules] 1 1 1, 1 (1) : 1 1 1 2, 2 (1) : 1 1 1 3, 3 (1) : 1 1 1 4, 4 (1) : 1 1 2 1, 5 (1) : 1 40 1 2 2, 6 (1) : 1 1 2 3, 7 (1) : 1 1 2 4, 8 (1) : 1 2 1 1, 9 (1) : 1 2 1 2, 10 (1) : 1 2 1 3, 11 (1) : 1 2 1 4, 12 (1) : 1 2 2 1, 13 (1) : 1 2 2 2, 14 (1) : 1 2 2 3, 15 (1) : 1 2 2 4, 16 (1) : 1 3 1 1, 17 (1) : 1 3 1 2, 18 (1) : 1 3 1 3, 19 (1) : 1 3 1 4, 20 (1) : 1 3 2 1, 21 (1) : 1 3 2 2, 22 (1) : 1 3 2 3, 23 (1) : 1 3 2 4, 24 (1) : 1 4 1 1, 25 (1) : 1 4 1 2, 26 (1) : 1 4 1 3, 27 (1) : 1 4 1 4, 28 (1) : 1 4 2 1, 29 (1) : 1 4 2 2, 30 (1) : 1 4 2 3, 31 (1) : 1 4 2 4, 32 (1) : 1 41 APPENDIX B Membership Function Plots and Surface Plot 42 43 44 45 APPENDIX C Flight Simulation Results Visibility Pilot Experience Airspeed Result 15 2000 100 0 14 2000 95 0 13 2000 90 0 12 2000 85 0 11 2000 80 0 10 2000 75 1 9 2000 70 1 8 2000 65 1 7 2000 60 1 6 2000 55 1 5 2000 50 0 4 2000 45 0 3 2000 40 0 2 2000 100 0 1 2000 95 0 0 2000 90 0 15 500 100 0 14 500 95 0 13 500 90 0 12 500 85 0 11 500 80 0 10 500 75 0 9 500 70 1 8 500 65 1 46 7 500 60 1 6 500 55 1 5 500 50 0 4 500 45 0 3 500 40 0 2 500 100 0 1 500 95 0 0 500 90 0 15 2000 40 0 14 2000 45 0 13 2000 50 0 12 2000 55 1 11 2000 60 1 10 2000 65 1 9 2000 70 1 8 2000 75 1 7 2000 80 0 6 2000 85 0 5 2000 90 0 4 2000 95 0 3 2000 100 0 2 2000 40 0 1 2000 45 0 0 2000 50 0 15 500 40 0 14 500 45 0 13 500 50 0 12 500 55 1 47 11 500 60 1 10 500 65 1 9 500 70 1 8 500 75 0 7 500 80 0 6 500 85 0 5 500 90 0 4 500 95 0 3 500 100 0 2 500 40 0 1 500 45 0 0 500 50 0 15 2000 55 1 14 2000 60 1 13 2000 65 1 12 2000 70 1 11 2000 75 1 10 2000 80 0 9 2000 85 0 8 2000 90 0 7 2000 95 0 6 2000 100 0 5 2000 40 0 4 2000 45 0 3 2000 50 0 2 2000 55 1 1 2000 60 1 0 2000 65 0 48 15 500 70 1 14 500 75 0 13 500 80 0 12 500 85 0 11 500 90 0 10 500 95 0 9 500 100 0 8 500 40 0 7 500 45 0 6 500 50 0 5 500 55 1 4 500 60 1 3 500 65 1 2 500 70 1 1 500 75 0 0 500 80 0 49 REFERENCES [1] Federal Aviation Administration Flight Standards Service “Instrument Flying Handbook 2008” FAA-H-8081-15A, Instrument Flying Handbook, dated 2007 [2] Federal Aviation Administration Flight Procedure Standards Branch” Instrument Procedures Handbook 2007” FAA-H-8261-1A [3] The MathWorks, Inc “Fuzzy Logic Toolbox™ User’s Guide R2011b” September 2011 Version 2.2.14 (Release 2011b) [4] Zadeh, L.A., “Fuzzy sets,” Information and Control, Vol. 8, pp. 338-353, 1965.