Cooperative Aerial Load Transport with Force Control

We consider a group of aerial manipulators (AM) collaboratively transporting a flexible payload. Each AM is a combination of an Unmanned Aerial Vehicle (UAV) with a two degree-of-freedom robotic manipulator (RM) attached to it. Contact forces between the agents (AMs) and the payload are modeled as the gradient of nonlinear potentials that describe the deformation of the payload. We develop an adaptive decentralized control law for transporting a payload with an unknown mass without explicit communication between the agents. The algorithm guarantees that all the agents converge to a desired velocity and the contact forces are regulated. The sum of the estimates of the unknown mass from all the agents converge to the true mass. Using the inverse kinematics of the AM, we implement the developed algorithm at the kinematic level for the AMs and demonstrate its effectiveness in simulations. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.