AN IMPROVED EVALUATION METHOD FOR AIRPLANE SIMULATOR MOTION CUEING

115 Pages·2002·1.32 MB·English

AN IMPROVED EVALUATION METHOD
FOR AIRPLANE SIMULATOR MOTION CUEING

by
Alex Marodi
B.S. in E.E., University of Pittsburgh, 1991

Submitted to the Graduate Faculty of
the School of Engineering in partial fulfillment
of the requirements for the degree of
Master of Science

University of Pittsburgh
2002
UNIVERSITY OF PITTSBURGH
SCHOOL OF ENGINEERING

This thesis was presented
by

Alex Marodi

It was defended on

April 17, 2002
and approved by
M. A. Simaan, Ph. D., Professor, Electrical Engineering
Thesis Advisor

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AN IMPROVED EVALUATION METHOD
FOR AIRPLANE SIMULATOR MOTION CUEING
Alex Marodi, M.S.
University of Pittsburgh, 2002

The lack of sufficient evaluation criteria for motion systems has contributed to
perceivable differences in motion cues among similar airplane simulators. To resolve
this issue, criteria for simulator motion cueing and evaluation must be developed to
insure uniform and optimum cues within a motion system’s workspace. Therefore, an
improved evaluation method is proposed to enable a better assessment of motion
cueing within the workspace.
To demonstrate the effectiveness of the improvement, an off-line simulation of a
motion system is developed and used for the evaluation. A common motion cueing
algorithm is incorporated in the simulation to control a motion platform model. Test
signals that approximate typical airplane specific forces, for selected maneuvers, are
used to drive the simulation. During each simulation test run, a platform trajectory is
recorded for the maneuver. The trajectory data are then processed by an optimization
routine that determines the dynamic workspace limits as a function of the trajectory. The
time histories of the trajectory and the workspace limits are then plotted for evaluation.
Presenting the platform trajectory along with the dynamic workspace limits
provides another way of evaluating the quality of motion cues within the workspace.
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Augmenting the existing motion criteria that are used in current evaluation methods with
criteria based on the dynamic workspace limits yields an improved evaluation method.
This improved evaluation method contributes to the development of criteria for motion
evaluation.
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ACKNOWLEDGEMENTS

I would like to thank Dr. M. A. Simaan, my advisor, for his guidance and
assistance in the preparation of this thesis.
Also, I would like to thank Prof. F. Cardullo and Mr. R. Telban of the State
University of New York at Binghamton for providing information on their contributions to
the on-going research in the field of motion cueing.
I would especially like to thank my wife, Annette, and children, Luke, Rachel,
Anna, and Leah, for their patience, understanding, and support.
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TABLE OF CONTENTS

1.0 INTRODUCTION.......................................................................................................1
1.1 Motivation ............................................................................................................1
1.2 Research Objective..............................................................................................3
1.3 Outline .................................................................................................................6
2.0 DESCRIPTION AND MATH MODEL OF A MOTION SYSTEM.................................8
2.1 Introduction..........................................................................................................8
2.1.1 Airplane Simulator Motion System...............................................................8
2.1.2 Basis for the Motion System Regulatory Requirement..............................11
2.1.3 Psychophysical Perception of Motion........................................................12
2.1.4 Concept of Motion Cueing.........................................................................15
2.2 Math Model of a Motion System.........................................................................17
2.2.1 Motion System Input Component ..............................................................19
2.2.1.1 Radius Vector R and the Motion System Reference Point................24
2.2.2 Motion Cueing Component........................................................................27
2.2.2.1 Scaling and Limiting..........................................................................29
2.2.2.2 Frame Transformations.....................................................................31
2.2.2.3 Adaptive Filtering...............................................................................35
2.2.2.4 Integration.........................................................................................47
2.2.3 Motion Actuator Transformation Component.............................................49
2.2.4 Motion Actuator Model Component ...........................................................54
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2.3 Summary ...........................................................................................................54
3.0 EVALUATION OF MOTION CUEING......................................................................56
3.1 Introduction........................................................................................................56
3.2 Current Motion Qualification Criteria and Evaluation Issues..............................56
3.2.1 Current Motion Qualification Criteria..........................................................56
3.2.2 Motion Evaluation Issues...........................................................................58
3.3 Motion Workspace Evaluation............................................................................60
3.3.1 Motion Actuator Inverse Transformation....................................................62
3.3.2 Optimization Routine to Solve the Dynamic Workspace Limits..................67
3.3.3 Simulation Results and Discussion............................................................73
3.4 Improved Method for Evaluating Motion Cueing................................................81
3.4.1 Combining Inverse Transformation and the Workspace Limits Routine.....83
3.4.2 Simulation Results and Discussion............................................................85
4.0 DISCUSSION AND CONCLUSION.........................................................................97
4.1 Discussion .........................................................................................................97
4.2 Conclusion.........................................................................................................98
BIBLIOGRAPHY .........................................................................................................100

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LIST OF TABLES

Table 2.1 Values for the Adaptive Filter Parameters...............................................49
Table 2.2 Coordinates for the Actuator Attachment Points......................................52
Table 3.1 Typical Motion Performance Limits..........................................................61
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LIST OF FIGURES

Figure 2.1 Airplane Simulator with a Six Degrees-Of-Freedom Motion System........9
Figure 2.2 Factors that Influence Pilot-Airplane Performance.................................12
Figure 2.3 Basic Structure of Motion and Orientation Perception Model.................13
Figure 2.4 Perception Model Response to Visual and Inertial Motion Cues ...........15
Figure 2.5 Block Diagram of Typical Motion System...............................................18
Figure 2.6 Definition of Vector Components in the Airplane Equations of Motion...20
Figure 2.7 Centroid of the Motion System Platform................................................25
Figure 2.8 Illustration of Airplane, Simulator, and Inertial Reference Frames.........26
Figure 2.9 Block Diagram of the Motion Cueing Component..................................28
Figure 2.10 Scaling and Limiting Function for f ..................................................30
x,c,o
Figure 2.11 Motion System Geometry.....................................................................50
Figure 2.12 Vector Diagram for Actuator i...............................................................51
Figure 3.1 Steepest Descent Flow Chart for Dynamic Workspace Limits...............71
Figure 3.2 Z Axis Upper Limit Search Trajectory.....................................................73
Figure 3.3 Z Axis Lower Limit Search Trajectory.....................................................74
Figure 3.4 Z Axis Upper Limit Search Trajectory.....................................................75
Figure 3.5 Z Axis Lower Limit Search Trajectory.....................................................76
Figure 3.6 Motion Workspace Limits for α = [0,0,0,0,0,0]......................................77
n
Figure 3.7 Motion Workspace Limits for α = [1,0,0,0,0,0]......................................79
n
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Figure 3.8 Motion Workspace Limits for α = [0.5,0,0,0,0.2,0]................................80
n
Figure 3.9 Flowchart for the Off-line Motion Simulation..........................................82
Figure 3.10 Simplified Motion Block Diagram.........................................................84
Figure 3.11 Motion Block Diagram with Motion Data Post Processing System.......85
Figure 3.12 Test Case 1: Specific Force Inputs and Platform X Acceleration..........88
Figure 3.13 Test Case 1: Platform Positions and Workspace Limits.......................89
Figure 3.14 Unfiltered and Filtered Z Limit Signals.........................................91
platform
Figure 3.15 Filtered Z Limit Signals................................................................92
platform
Figure 3.16 Test Case 1A: Specific Force Inputs and Platform X Acceleration.......93
Figure 3.17 Test Case 1A: Platform Positions and Workspace Limits.....................94
Figure 3.18 Test Case 1B: Platform Positions and Workspace Limits.....................96

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