dynamic characterization and analysis of aerial lifts - SMARTech

99 Pages·2012·21.14 MB·English

DYNAMIC CHARACTERIZATION AND ANALYSIS
OF AERIAL LIFTS
A Thesis
Presented to
The Academic Faculty
by
Eileen C. Hernandez
In Partial Fulfillment
of the Requirements for the Degree
Master of Science in the
George W. Woodruff School of Mechanical Engineering
Georgia Institute of Technology
December 2012
DYNAMIC CHARACTERIZATION AND ANALYSIS
OF AERIAL LIFTS
Approved by:
Dr. William Singhose, Advisor
George W. Woodruff School of Mechanical
Engineering
Georgia Institute of Technology
Dr. Aldo Ferri
George W. Woodruff School of Mechanical
Engineering
Georgia Institute of Technology
Dr. Joshua Vaughan
School of Mechanical Engineering
University of Louisiana at Lafayette
Date Approved: 10 October 2012
ACKNOWLEDGEMENTS
I want to thank my advisor, Dr. William Singhose, for his support and guidance. His
enthusiasm of his research continues to inspire the most doubtful of graduate students and
thenceforth appears constantly in their everyday life. I would also like to thank my com-
mitteemembers, Dr. AldoFerriandDr. JoshuaVaughan, fortheirinfluenceinmyresearch
through the courses they lecture and for their support of my research. I would also like to
thank the GEM Fellowship for their financial support to complete a thesis for my Degree
Master of Science.
I owe a debt of gratitude to my parents, Acelia and Raul, who have constantly supported
my passion for engineering and running. I am blessed to have hard-working parents that
have provided me great opportunities in life and help me achieve my dreams.
Lastly, I would like to thank Ehsan Maleki and Daichi Fujioka for providing assistance
of this research.
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TABLE OF CONTENTS
ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi
LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
SUMMARY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
I INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Description and Categorization of Aerial Lifts . . . . . . . . . . . . . . . . 2
1.1.1 Vertical Lifts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.1.2 Vertical and Horizontal Lifts . . . . . . . . . . . . . . . . . . . . . . 7
1.1.3 Hazards of Aerial Lifts . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.1.4 Reduction of Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . 19
1.2 Input Shaping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1.3 Thesis Contributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
1.4 Thesis Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
II FULL-SIZE AERIAL LIFT OSCILLATION EXPERIMENTS . . . . . 26
2.1 Scissor Lift Oscillations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.1.1 Machine-Motion Induced Oscillations . . . . . . . . . . . . . . . . . 26
2.1.2 Operator-Induced oscillations . . . . . . . . . . . . . . . . . . . . . 29
2.2 Aerial Lift Machine-Motion Induced oscillation. . . . . . . . . . . . . . . . 30
2.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
III DYNAMIC OSCILLATION ANALYSIS OF DOUBLE-BOOM ARTIC-
ULATING AERIAL LIFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.1 Model Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.2 Overcenter Luffing Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.3 Slewing Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.3.1 Slewing Only Oscillation . . . . . . . . . . . . . . . . . . . . . . . . 41
3.3.2 Slewing combined with Elbow Luffing Oscillation . . . . . . . . . . 49
3.4 Slewing Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
3.5 Input Shaping to Reduce Oscillation . . . . . . . . . . . . . . . . . . . . . 52
iv
3.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
IV TIP-OVERANALYSISOFDOUBLE-BOOMARTICULATINGAERIAL
LIFTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.1 Static Telescopic Articulating Aerial Lift Tip-Over . . . . . . . . . . . . . 57
4.1.1 Stability Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.1.2 Parameter Determination . . . . . . . . . . . . . . . . . . . . . . . 58
4.1.3 Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
4.1.4 Effects of Added Mass on Platform . . . . . . . . . . . . . . . . . . 65
4.2 Dynamic Model Articulating Aerial Lift . . . . . . . . . . . . . . . . . . . 68
4.2.1 Tip-Over Stability Margin . . . . . . . . . . . . . . . . . . . . . . . 68
4.2.2 Stability Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
4.3 Experimental Setup and Maximum Static Payload Mass . . . . . . . . . . 74
4.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
V CONCLUSIONS AND FUTURE WORK . . . . . . . . . . . . . . . . . . 78
5.1 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
5.2 Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
APPENDIX A — STATIC STABILITY MOTION GENESIS CODE . 80
APPENDIX B — DYNAMIC MODEL OF DOUBLE-BOOM ARTICU-
LATING AERIAL WORK LIFT AUTOLEV CODE . . . . . . . . . . . 84
REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
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LIST OF TABLES
1 Categorization table of aerial work lifts. . . . . . . . . . . . . . . . . . . . . 4
2 Overcenter and non-overcenter constraints. . . . . . . . . . . . . . . . . . . 13
3 Risk assessment for articulated aerial lifts. . . . . . . . . . . . . . . . . . . . 19
4 Residual oscillation from vertical drops of a scissor lift in millimeters. . . . 29
5 Base parameters and measurements. . . . . . . . . . . . . . . . . . . . . . . 33
6 Lengths and masses of model articulating lift. . . . . . . . . . . . . . . . . . 33
7 Flexibility parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
8 Velocity and acceleration limits. . . . . . . . . . . . . . . . . . . . . . . . . . 35
9 Cherry picker experimental weights in kilograms. . . . . . . . . . . . . . . . 75
10 Cherry picker experimental dimensions in meters. . . . . . . . . . . . . . . . 75
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LIST OF FIGURES
1 An Altec truck-mounted articulating aerial lift working on electrical lines. . 1
2 Two Categories of Aerial Lift Motion. . . . . . . . . . . . . . . . . . . . . . 2
3 Examples of mobile and immobile aerial lifts. . . . . . . . . . . . . . . . . . 3
4 Palfinger’s vehicle-mounted bridge inspection lift performing maintenance
under a bridge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5 Genie GS-1530 scissor lift with cab base. . . . . . . . . . . . . . . . . . . . . 6
6 Haulotte immobile vertical mast lift. . . . . . . . . . . . . . . . . . . . . . . 7
7 JLG’s Liftpod that uses a pulley system . . . . . . . . . . . . . . . . . . . . 7
8 Movements of vertical and horizontal motion aerial lifts. . . . . . . . . . . . 8
9 Altec articulating aerial lift. . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
10 Genie S-60’s Trax cab base telescopic aerial lift. . . . . . . . . . . . . . . . . 9
11 Genie Z-60/34 cab base telescopic articulating lift. . . . . . . . . . . . . . . 9
12 Genie TZ-50 is a skeletal base telescopic articulating lift. . . . . . . . . . . . 10
13 An elevated cherry picker. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
14 A cab-mounted aerial lift used to perform work on a building at MIT. . . . 11
15 Non-overcenter articulating aerial lift allowable motions. . . . . . . . . . . . 12
16 Overcenter articulating aerial lft allowable motions. . . . . . . . . . . . . . . 13
17 A truck-mounted aerial lift working on power lines. . . . . . . . . . . . . . 14
18 A tipped over aerial work lift. . . . . . . . . . . . . . . . . . . . . . . . . . 16
19 Hazard of an operator crushed between the control panel and an obstacle. . 16
20 Altec AT237 articulating aerial lift showing the less supported platform. . . 18
21 Different types of outriggers used to stabilize aerial lifts. . . . . . . . . . . . 20
22 Aerial lift with both outrigger types. . . . . . . . . . . . . . . . . . . . . . . 20
23 Configurations with greater probability of tip-over on articulating lifts. . . . 21
24 Solution to hazard of an operator crushed between the control panel and an
obstacle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
25 Input shaping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
26 A scissor lift in the high-bay of the MaRC building at the Georgia Institute
of Technology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
27 First residual oscillation recorded from a vertical drop by a scissor lift. . . . 28
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28 Second residual oscillation recorded from a vertical drop by a scissor lift. . . 28
29 Third residual oscillation recorded from a vertical drop by a scissor lift. . . 28
30 Diagram of impulse conducted on scissor lift. . . . . . . . . . . . . . . . . . 30
31 Operator induced scissor lift oscillation. . . . . . . . . . . . . . . . . . . . . 30
32 Second operator induced scissor lift oscillation. . . . . . . . . . . . . . . . . 30
33 Aerial lifts seen working together near Georgia Tech. . . . . . . . . . . . . . 31
34 Residual oscillation from an observed aerial lift movement. . . . . . . . . . . 31
35 Double-boom articulating aerial lift. . . . . . . . . . . . . . . . . . . . . . . 33
36 Top view of dynamic model articulating aerial lift. . . . . . . . . . . . . . . 33
37 Dynamic model of double-boom articulating aerial lift. . . . . . . . . . . . 34
38 Residual amplitude from a shoulder move from 30◦ to 90◦ with different
initial elbow angles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
39 Residual amplitude from a shoulder move from 30◦ to 90◦ with initial elbow
angle of 180◦. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
40 Significant configurations of cherry picker during a 60◦ shoulder move with
different initial elbow angles. . . . . . . . . . . . . . . . . . . . . . . . . . . 40
41 Residual amplitude resulting from a 60◦ shoulder move with different initial
elbow and shoulder angles.. . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
42 Largest maximum residual amplitude resulting from a 60◦ shoulder move
with initial shoulder and elbow angles of 50◦ and 180◦, respectively. . . . . 41
43 Cherry picker configuration of 30◦ shoulder angle and 160◦ elbow angle with
a displacement of slew of 160◦. . . . . . . . . . . . . . . . . . . . . . . . . . 42
44 Residual oscillation from a 160◦ slew move of a cherry picker in an extended
configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
45 Residual oscillation from a 160◦ slew move of a cherry picker in a compact
configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
46 Residual amplitude from a 60◦ slew move with different initial elbow angles. 43
47 Largest residual amplitude from a 60◦ slew move occurred at an initial elbow
angle of 210◦. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
48 Significant configurations of cherry picker during a 60◦ slew move with dif-
ferent initial elbow angles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
49 Residualamplituderesultingfroma60◦ slewmovewithdifferentinitialelbow
and shoulder angles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
50 Largest residual amplitudefrom a60◦ slew move occurred atan initialshoul-
der and elbow angles of 0◦ and 180◦, respectively. . . . . . . . . . . . . . . . 45
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51 Secondpeakinresidualamplitudefroma60◦ slewmoveoccurredataninitial
shoulder and elbow angles of 120◦ and 120◦, respectively. . . . . . . . . . . 46
52 Residual amplitude of slew moves from 0◦ to 300◦ of a cherry picker. . . . . 47
53 Configurations of compact and extended cherry pickers for slew moves. . . . 47
54 Comparison of maximum residual oscillations in the x, y, and z directions
for different slew moves at a set elbow angle of 120◦. . . . . . . . . . . . . . 48
55 Maximum residual oscillation in x and y directions for different slew moves
and different initial elbow angles. . . . . . . . . . . . . . . . . . . . . . . . . 48
56 Maximum residual oscillations in x, y, and z directions for different slew
displacements and initial elbow angles. . . . . . . . . . . . . . . . . . . . . . 49
57 Residual oscillation from a 160◦ slew and 60◦ elbow moves of a cherry picker. 50
58 Initial configuration of the cherry picker for the slew and elbow luffing moves. 50
59 Residual amplitude of slew and elbow luff moves from 0◦ to 180◦ and 0◦ to
240◦, respectively.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
60 Configurations throughout the moving the slew and elbow angles 180◦ that
generated the largest residual amplitude. . . . . . . . . . . . . . . . . . . . . 51
61 Comparison of frequencies in the x, y, and z directions for different slew
moves at a set elbow angle of 120◦. . . . . . . . . . . . . . . . . . . . . . . . 52
62 Frequencies in x, y, and z directions for different slew displacements and
initial elbow angles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
63 Comparison of shaped and unshaped residual oscillation from a 160◦ slew
move of a cherry picker. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
64 Comparison between shaped and unshaped residual oscillation from a 160◦
slew and 60◦ elbow move of a cherry picker. . . . . . . . . . . . . . . . . . . 55
65 Comparisonbetweenshapedandunshapedresidualamplitudefromslewand
elbow luff moves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
66 Model of the Grove A125J Articulated Telescoping Aerial Lift. . . . . . . . 58
67 Machine Dimensions (Red Indicates Calculated Lengths) . . . . . . . . . . . 59
68 COM Location in Official Literature . . . . . . . . . . . . . . . . . . . . . . 59
69 Simulated COM Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
70 Two Different Configurations that Produce the Same Platform Position . . 61
71 Configuration-Dependent Stability . . . . . . . . . . . . . . . . . . . . . . . 61
72 “Advertised” Stable Work Area [3] . . . . . . . . . . . . . . . . . . . . . . . 62
73 Potentially-Stable Model Area. . . . . . . . . . . . . . . . . . . . . . . . . . 62
74 Building Location Relative to the Device (Image Mirrored from Video) . . . 63
ix
75 Workspace with Riser Fixed at 72◦ . . . . . . . . . . . . . . . . . . . . . . . 64
76 ExamplesofStableandUnstableConfigurationsReachingthesamePlatform
Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
77 Potentially-Stable Platform Locations . . . . . . . . . . . . . . . . . . . . . 66
78 Potentially-Unstable Platform Locations . . . . . . . . . . . . . . . . . . . . 66
79 Points that Can Be Either Stable or Unstable . . . . . . . . . . . . . . . . . 66
80 Demonstrating Configuration Dependent Stability . . . . . . . . . . . . . . 66
81 Potentially stable and unstable platform locations for platform masses of 500
kg and 1000 kg. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
82 Potentially unstable platform locations for a platform mass of 500 kg. . . . 67
83 Potentially unstable platform locations for a platform mass of 1000 kg. . . . 67
84 General 3D tip-over stability margin geometry. . . . . . . . . . . . . . . . . 69
85 Equivalent force couple at the center of mass. . . . . . . . . . . . . . . . . . 70
86 Comparison between dynamic and static tip-over stability margin. . . . . . 71
87 Comparison of dynamic tip-over stability margin for added platform mass. . 72
88 Overcenter and non-overcenter configurations with the same end location. . 73
89 Comparison of dynamic tip-over stability margin for overcenter and non-
overcenter configurations with the same end location. . . . . . . . . . . . . . 73
90 Comparison of slewing-induced residual amplitude for overcenter and non-
overcenter configurations with the same end location. . . . . . . . . . . . . . 74
91 Comparison of simulation and experimental results of maximum static pay-
load mass for a base width of 0.43 meters. . . . . . . . . . . . . . . . . . . . 76
92 Comparison of simulation and experimental results of maximum static pay-
load mass for a base width of 0.33 meters. . . . . . . . . . . . . . . . . . . . 76
93 Comparison of experimental results of maximum static payload mass for
different base widths. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
x