We present object handling and transport by a multi-robot team with a
deformable sheet as a carrier. Due to the deformability of the sheet and the
high dimension of the whole system, it is challenging to clearly describe all
the possible positions of the object on the sheet for a given formation of the
multi-robot system. A complete forward kinematics (FK) method is proposed in
this paper for object handling by an N-mobile robot team with a deformable
sheet. Based on the virtual variable cables model, a constrained quadratic
problem (CQP) is formulated by combining the form closure and minimum potential
energy conditions of the system. Analytical solutions to the CQP are presented
and then further verified with the force closure condition. With the proposed
FK method, all possible solutions are obtained with the given initial sheet
shape and the robot team formation. We demonstrate the effectiveness,
completeness, and efficiency of the FK method with simulation and experimental
results.Comment: 8 pages, 6 figures, has been submitted to IEEE Robotics and
Automation Letter