Roll Ratcheting: Cause and Analysis. Gordon Hohne. Institut fur Flugsystemtechnik Braunschweig. 268 pages 155 figures 87 tables 187 references

Transcription

1 Deutsches Zentrum fur Luft- und Raumfahrt e.v. Forschungsbericht Roll Ratcheting: Cause and Analysis Gordon Hohne Institut fur Flugsystemtechnik Braunschweig 268 pages 155 figures 87 tables 187 references DLR

2 IV \ Nomenclature ; IX 1. Introduction ' Background Control System Technologies Aircraft-Pilot Coupling State of the Art Experimental Assessment Methods Numerical Assessment Methods Objective What Is to Come Roll Ratcheting Background Other Explanations Switching from Bank Angle Control to Angular Acceleration Control Interaction between the Pilot's Neuromuscular System and the Inceptor Pilot's Inappropriate Use of the Vestibular Gain Incidents Operational Flights, Flight Tests, Prototype Flights In-Flight Research Programs Motion Base Simulation Programs Roll Ratcheting Database Alleviation Methods Attenuation of the Pilot Input Adaptive Filtering Attenuation of Feedback Signals Phase Lag Reduction < Inceptor Sensitivity Changes Feel System Modifications Mechanical Solutions Summary Numerical Assessment of Handling Qualities Fundamentals Experimental Prerequisites Numerical Analysis 40

3 . V 3.2 Mathematical Description of the Aircraft Linear Equations Frequency Domain Lateral-Directional Dynamics Eigenvalues Integral Aircraft Model Handling Qualities Criteria Classification Maximum Roll Mode Time Constant Maximum Roll Time Delay Lateral Acceleration at the Pilot's Station Maximum Roll Control Sensitivity Roll Performance Phase Rate Criterion OLOP Criterion Roll Ratcheting Criteria Approaches Minimum Values of the Roll Mode Time Constant Roll Control Effectiveness Roll Rate Time History Criterion Feel System Dynamics Effective Time Delay versus Jerk Parameter Steady State Roll Rate per Inceptor Force Gradient Steady State Roll Rate per Roll Mode Time Constant versus Effective Time Delay Phase Lag Approach General Deficiencies A New Roll Ratcheting Prediction Criterion Summary Modeling the Human Pilot ' Quasi-Linear Behavioral Models Crossover Model Structural Model of the Human Pilot Biomechanical Models Model by W. Allen, H. Jex, and R. Magdaleno Model by M. van Paassen Model by R. Koehler Summary New Biomechanical Pilot Models Development Approaches Computer Based Approach 94

4 VI Software Pilot Model Setup Interface to External Software Determination of Model Parameters Consideration of Measurement Conditions Parameter Identification in the Frequency Domain Results for the Koehler Model New Pilot Model Topologies Development Selection Analytical Representation of the Selected Pilot Model Summary Validation LATHOS Database Description Results F-18 Database Description Results IFS Database..' Description Results F-16XL Description Results Russian Transport Aircraft Description Results Summary Interpretation of the Roll Ratcheting Phenomenon Pilot Model Eigenvectors Pole Distribution High Performance Aircraft Elastic Transport Aircraft Aircraft Parameter Studies ; Dominant Acceleration Feedbacks Roll Mode Time Constant Steady State Roll Rate per Inceptor Force 144

5 VII 13A Time Delay < Damping of the Dutch Roll Mode First Order Prefilter Time Constants Second Order Prefilter Dynamics Force/Deflection Gradient Command Architecture Feel System Dynamics Location of the Seat above the Roll Axis Elasticity Pilot Parameter Studies Mass of the Limbs Muscle Tension Summary Summary and Outlook 162 Literature 166 Appendices A: Background Information about the Nichols Diagram 176 A.I Assessment of the Closed-Loop Stability 176 A.2 Gain and Phase Margins 176 A.3 Closed-Loop Frequency Response 177 B: Parameter Identification Fundamentals 179 B.I Maximum Likelihood Cost Function 179 B. 1.1 Known Measurement Noise Covariance Matrix 180 B.1.2 Unknown Measurement Noise Covariance Matrix 181 B.2 Optimization 183 B.3 Assessment of the Estimation 185 C: Developed Pilot Models 187 C.I S_3b 188 C.2 SJbexm 190 C.3 S_3bjm 192 C.4 S_3b_xl 194 C.5 S_3b_xl_exm 196 C.6 S 3b tt 198

6 VIII C.I S_3b_tf 200 C.8 S_3b_hg ". 202 C.9 S_3b_hg_xl 204 C.10S_el_4b 206 C.ll S_el_4b_of 208 C.12 S_el_4b_xl 210 C.13 S_el_4b_xl_em 212 C.14S_wa_4b 214 C.15 S_wa_4b_xl 216 C.16S_wa_xl_hg 218 C.17 S_wa_xl_hg_sg 220 C.18 S_wa_4b_xl_sg 222 D: Analytical Derivation of the Pilot Model Equations of Motion 224 D.I Kinematics 224 D.I.I Translatory Motion 224 D.1.2 Rotatory Motion 226 D.2 Lagrange Equation 227 D.3 Calculation of the Selected Biomechanical Pilot Model 229 E: Evaluation Tables 241 E.I LATHOS Database 242 E.2 F-18 Database " 245 E.3 IFS Database 246 E.4 Graphical Representation of the Evaluation Result 250