The stochastic vibration of a flexible, articulated, and mobile manipulator is studied. The manipulator is mounted on a vehicle which is supported by a suspension system. Stochastic excitation of the manipulator is induced by the uniform horizontal motion of the vehicle on a traction surface. The power spectral density representation and the state-space representation are used to derive expressions for the covariance matrices of the manipulator tip motions. Sensitivity of the variance of the tip motion to the manipulator configuration, length, vehicle velocity, surface roughness coefficient, and structural damping and stiffness are explored. Suggestions for mobile manipulator design to minimize the influence of the stochastic base vibration on the manipulator tip motion are proposed.

Issue Section:
Technical Papers
Topics:
Manipulators, Vibration, Vehicles, Damping, Excitation, Manipulator design, Spectral energy distribution, Stiffness, Surface roughness, Suspension systems, Traction
1.
Akpan, U. O., 1996, “Dynamics of Mobile Manipulator Structures,” Ph.D. thesis, Technical University of Nova Scotia, Nova Scotia, Canada.
2.
Hac
 
A.
,
1985
, “
Suspension Optimization of a 2 DOF Vehicle Model Using ‘Stochastic Optimal Control Technique,’
”
Journal of Sound and Vibration
, Vol.
100
, No.
3
, pp.
343
–
357
.
3.
Hootsmans, N. A. M., and Dubowsky, S., 1991, “Large motion Control of mobile Manipulators Including Vehicle Suspension Characteristics,” Proceedings IEEE International Conference on Robotics and Automation, Sacramento, CA, pp. 2336–2341.
4.
Jacobs, P., and Canny, J., 1989, “Planning Smooth Paths for Mobile Robots,” Proceedings IEEE International Conference on Robotics and Automation, Scottsdale, Az.
5.
Narayanan
 
S.
, and
Raju
 
G. V.
,
1990
, “
Stochastic Optimal Control of Non-Stationary Response of a Single-Degree-of-Freedom Vehicle Model
,”
Journal of Sound and Vibration
, Vol.
141
, No.
3
, pp.
449
–
463
.
6.
Smith
 
P. G.
,
1971
, “
Numerical Solution of the Matrix Equation AX + XAT + B = 0
”
IEEE Transaction on Automatic Control
, Vol.
AC-16
, pp.
278
–
279
.
7.
Spong, M. W., and Vidyasagar, M., 1989, Robot Dynamics and Control, John Wiley and Sons, New York.
8.
Yang, C. Y., 1986, Random Vibration of Structures, John Wiley and Sons, New York.
9.
Yun-Hui, L., and Suguru, A., 1991, “Proposal Tangent Graph and Extended Tangent Graph for Path Planning of Mobile Robots,” Proceedings IEEE International Conference on Robotics and Automation, Sacramento, CA, pp. 312–317.
This content is only available via PDF.
Copyright © 1997
 by The American Society of Mechanical Engineers
You do not currently have access to this content.