This paper describes the development of a suitable algorithm to compute the potential of tipping-over for vehicles that carry manipulators. The energy method developed by Messuri and Klein (1985) is extended here to quantitatively reflect the effect of forces and moments arising from the manipulation of the implement. The amount of the impact energy that can be sustained by the vehicle without tipping-over, about each edge of potential overturning is computed. First, the instantaneous onset of instability configuration of the machine about the edge is determined by constructing an equilibrium plane. Next, the work done by all acting forces and moments when the machine is virtually brought to this unstable stance from the current state, is calculated. This work is the indication of the proximity of the machine to tipping-over around that edge. The application of this study is directed at industrial mobile machines that carry human-operated hydraulic manipulators. The algorithm is therefore used to study the stability of an excavator based log-loader. Simulation studies clearly show the importance of inertial loads in determining the stability of such machines.

1.
Choi
 
B. S.
, and
Song
 
S. M.
,
1989
, “
Fully Automated Obstacle-Crossing Gaits for Walking Machines
,”
IEEE Transactions on Systems, Man, and Cybernetics
, Vol.
18
, No.
6
, pp.
952
964
.
2.
Courteau, J., 1994, “Robotics in Canadian Forestry,” IEEE Canadian Review, Winter Issue, pp. 10–13.
3.
Davidson
 
J. K.
, and
Schweitzer
 
G.
,
1990
, “
A Mechanics-Based Computer Algorithm for Displaying the Margin of Static Stability in Four-Legged Vehicles
,”
ASME Journal of Mechanical Design
, Vol.
112
, pp.
480
487
.
4.
Dubowsky, S., and Vance, E. E., 1989, “Planning Mobile Manipulator Motions Considering Vehicle Dynamic Stability Constraints,” Proceedings IEEE International Conference on Robotics and Automation, Scottsdale, AZ, Vol. 3, pp. 1271–1276.
5.
Frank
 
A. A.
,
1971
, “
On the Stability of an Algorithmic Biped Locomotion Machine
,”
Journal of Terramechanics
, Vol.
8
, No.
1
, pp.
41
50
.
6.
Ghasempoor, A., 1994, “A Measure of Stability for Mobile Manipulators with Application to Heavy-Duty Hydraulic Machines,” M.Sc. thesis, Department of Mechanical and Industrial Engineering, University of Manitoba, Winnipeg, Manitoba, Canada.
7.
Ghasempoor, A., and Sepehri, N., 1995a, “A Measure of Machine Stability for Moving Base Manipulators,” Proceedings IEEE International Conference on Robotics and Automation, Nagoya, Japan, Vol. 3, pp. 2249–2254.
8.
Ghasempoor, A., and Sepehri, N., 1995b, “A Model for Actuator Travel Limit Simulation,” Proceedings 15th Canadian Congress of Applied Mechanics, Victoria, Canada, Vol. 2, pp. 812–813.
9.
Huang
 
Z. M.
, and
Waldron
 
K. J.
,
1993
, “
Relationship Between Payload and Speed in Legged Locomotion Systems
,”
IEEE Transactions on Robotics and Automation
, Vol.
6
, No.
5
, pp.
570
577
.
10.
Hunt, K. H., 1978, Kinematic Geometry of Mechanisms, Clarendon Press, Oxford.
11.
Lawrence, P. D., Sassani, F., Sauder, B., Sepehri, N., and Wallersteiner, U., and Wilson, J., 1993, “Computer-Assisted Control of Excavator Based Machines,” SAE Technical Paper #932486, Presented at Int. Off-Highway & Power Plant Congress & Exploration, Milwaukee, Session 7F17, 10 pages.
12.
Lawrence, P. D., Sepehri, N., Sassani, F., and Chan, D., 1994, “Coordinated Hydraulic Control of Excavator Based Machines,” Proceedings 2nd Tampere International Conference on Machine Automation, Tampere, Finland, pp. 355–367.
13.
Li, Y., and Frank, A. A., 1986, “A Moving Base Robot,” Proceedings American Control Conference, Seattle, WA, pp. 367–373.
14.
Lin, B. S., and Song, S. M., 1993, “Dynamic Modeling, Stability and Energy Efficiency of A Quadrupedal Walking Machine,” Proceedings IEEE International Conference on Robotics and Automation, Atlanta, GA, Vol. 3, pp. 367–373.
15.
Luh
 
J. Y. S.
,
Walker
 
M. W.
, and
Paul
 
R. P. C.
,
1980
, “
On-Line Computational Scheme for Mechanical Manipulators
,”
ASME JOURNAL OF DYNAMIC SYSTEMS, MEASUREMENT, AND CONTROL
, Vol.
102
, pp.
69
76
.
16.
Messuri
 
D.
, and
Klein
 
C. A.
,
1985
, “
Automatic Body Regulation for Maintaining Stability of a Legged Vehicle During Rough-Terrain Locomotion
,”
IEEE Transactions on Robotics and Automation
, Vol.
1
, No.
3
, pp.
132
141
.
17.
McGhee
 
R. B.
, and
Frank
 
A. A.
,
1968
, “
On the Stability Properties of Quadruped Creeping Gait
,”
Mathematical Biosciences
, Vol.
3
, No.
2
, pp.
331
351
.
18.
McGhee
 
R. B.
, and
Iswandhi
 
G. I.
,
1979
, “
Adaptive Locomotion of a Multilegged Robot Over Rough Terrain
,”
IEEE Transactions on Systems, Man and Cybernetics
, Vol.
9
, No.
4
, pp.
176
182
.
19.
Nagy
 
P. V.
,
Desa
 
S.
, and
Whittaker
 
W. L.
,
1994
, “
Energy-Based Stability Measure for Reliable Locomotion of Statically Stable Walkers: Theory and Application
,”
International Journal of Robotics Research
, Vol.
13
, No.
9
, pp.
272
287
.
20.
Qian, J., and Gan, D., 1986, “Stability Study for Six-Legged Laterally-Walking Robots,” Proceedings American Society of Mechanical Engineers, Design Engineering Division (DE V15-3 PT3), New York, pp. 171–176.
21.
Seo
 
Y. J.
, and
Yoon
 
Y. S.
,
1994
, “
Design of a Robust Dynamic Gait of the Biped Using the Concept of Dynamic Stability Margin
,”
Robotica
, Vol.
13
, pp.
461
468
.
22.
Sepehri
 
N.
,
Lawrence
 
P. D.
,
Sassani
 
F.
, and
Frenetic
 
R.
,
1994
, “
Resolved-Mode Teleoperated Control of Heavy-Duty Hydraulic Machines
,”
ASME JOURNAL OF DYNAMIC SYSTEMS, MEASUREMENT, AND CONTROL
, Vol.
112
, No.
2
, pp.
232
240
.
23.
Sepehri
 
N.
,
Sassani
 
P.
,
Lawrence
 
P. D.
, and
Ghasempoor
 
A.
,
1996
, “
Simulation and Experimental Studies of Gear Backlash, Stick-Slip Friction and Joint-Limit in Heavy-Duty Hydraulic Machines
,”
ASME JOURNAL OF DYNAMIC SYSTEMS, MEASUREMENT, AND CONTROL
, Vol.
118
, pp.
463
467
.
24.
Song
 
S. M.
, and
Waldron
 
K. J.
,
1987
, “
An Analytical Approach for Gait Study and Its Applications on Wave Gaits
,”
International Journal of Robotics Research
, Vol.
6
, No.
2
, pp.
60
71
.
25.
Song, S. M., and Waldron, K. J., 1989, Machines that Walk, MIT Press, Cambridge, MA, pp. 100–118.
26.
Suganno, S., Huang, Q., and Kato, I., 1993, “Stability Criteria in Controlling Mobile Robotic Systems,” IEEE/RSJ International Conference on Intelligent Robots and Systems, Yokohama, Japan, pp. 832–838.
27.
Tafazoli, S., 1997, “Identification of Frictional Effects and Structural Dynamics for Improved Control of Hydraulic Manipulators,” Ph.D. thesis, University of British Columbia.
28.
Tafazoli, S., Lawrence, P. D., Salcudean S. E., Chan, D., Bachmann, S., and de Silva, C. W., 1996, “Parameter Estimation and Actuator Friction Analysis for a Mini Excavator,” Proceedings IEEE International Conference on Robotics and Automation, Minneapolis, MN, pp. 329–334.
29.
Wettergreen, D., and Thrope, C., 1992, “Gait Generation for Legged Robots,” Proceedings IEEE/RSJ International Conference on Intelligent Robots and Systems, Raleigh, NC, pp. 1413–1420.
This content is only available via PDF.
You do not currently have access to this content.