Maximum load carrying capacity of mobile manipulators: optimal control approach

Robotica ◽  
2009 ◽  
Vol 27 (1) ◽  
pp. 147-159 ◽  
Author(s):  
M. H. Korayem ◽  
A. Nikoobin ◽  
V. Azimirad
Keyword(s):  
Optimal Control ◽  
Optimal Control Problem ◽  
Control Problem ◽  
Carrying Capacity ◽  
Nonholonomic Constraints ◽  
Maximum Load ◽  
Mobile Manipulators ◽  
Load Carrying Capacity ◽  
Maximum Payload ◽  
Load Carrying

SUMMARYIn this paper, finding the maximum load carrying capacity of mobile manipulators for a given two-end-point task is formulated as an optimal control problem. The solution methods of this problem are broadly classified as indirect and direct. This work is based on the indirect solution which solves the optimization problem explicitly. In fixed-base manipulators, the maximum allowable load is limited mainly by their joint actuator capacity constraints. But when the manipulators are mounted on the mobile bases, the redundancy resolution and nonholonomic constraints are added to the problem. The concept of holonomic and nonholonomic constraints is described, and the extended Jacobian matrix and additional kinematic constraints are used to solve the extra DOFs of the system. Using the Pontryagin's minimum principle, optimality conditions for carrying the maximum payload in point-to-point motion are obtained which leads to the bang-bang control. There are some difficulties in satisfying the obtained optimality conditions, so an approach is presented to improve the formulation which leads to the two-point boundary value problem (TPBVP) solvable with available commands in different softwares. Then, an algorithm is developed to find the maximum payload and corresponding optimal path on the basis of the solution of TPBVP. One advantage of the proposed method is obtaining the maximum payload trajectory for every considered objective function. It means that other objectives can be achieved in addition to maximize the payload. For the sake of comparison with previous results in the literature, simulation tests are performed for a two-link wheeled mobile manipulator. The reasonable agreement is observed between the results, and the superiority of the method is illustrated. Then, simulations are performed for a PUMA arm mounted on a linear tracked base and the results are discussed. Finally, the effect of final time on the maximum payload is investigated, and it is shown that the approach presented is also able to solve the time-optimal control problem successfully.

scholarly journals Type Synthesis, Modelling and Analysis of the Manipulator for Wheel-Legged Robot

2016 ◽  
Vol 10 (2) ◽  
pp. 87-91
Author(s):  
Jarosław Szrek ◽  
Artur Muraszkowski ◽  
Przemysław Sperzyński
Keyword(s):  
Simulation Software ◽  
Dynamics Simulation ◽  
Mobile Manipulator ◽  
Mobile Manipulators ◽  
Legged Robot ◽  
Type Synthesis ◽  
Structural Synthesis ◽  
New Approach ◽  
Basic Dimension ◽  
Simulation Results

Abstract The aim of this article is to present the concept of wheel-legged mobile manipulator, which is a combination of mobile platform with specially selected suspension system and a manipulator. First, a literature review was performed and own solution proposed. The kinematic structure of manipulator, selected simulation results, physical model and the concept of the control system has been presented. Geometry synthesis was used to design basic dimension. Structural synthesis was performed according to the intermediate chain method. Simulations were performed using the multibody dynamics simulation software. New approach in the field of the mobile manipulators was presented as a result.

A Distributed Control Approach for the Boundary Optimal Control of the Steady MHD Equations

2013 ◽  
Vol 14 (3) ◽  
pp. 722-752 ◽  
Author(s):  
G. Bornia ◽  
M. Gunzburger ◽  
S. Manservisi
Keyword(s):  
Optimal Control ◽  
Control Problem ◽  
Distributed Control ◽  
Boundary Control ◽  
Optimal Solution ◽  
Mhd Equations ◽  
New Approach ◽  
Control Approach ◽  
Distributed Control Problem ◽  
Boundary Controls

AbstractA new approach is presented for the boundary optimal control of the MHD equations in which the boundary control problem is transformed into an extended distributed control problem. This can be achieved by considering boundary controls in the form of lifting functions which extend from the boundary into the interior. The optimal solution is then sought by exploring all possible extended functions. This approach gives robustness to the boundary control algorithm which can be solved by standard distributed control techniques over the interior of the domain.

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