# Decentralized Impedance Control for Cooperative Manipulation of Multiple Underwater Vehicle Manipulator Systems under Lean Communication

## TL;DR

This paper introduces a decentralized impedance control approach for cooperative underwater vehicle manipulators, enabling obstacle avoidance and load sharing without explicit communication, verified through simulations.

## Contribution

It proposes a novel distributed leader-follower architecture with implicit communication and a prescribed performance estimation law for cooperative underwater manipulation.

## Key findings

- Effective obstacle avoidance demonstrated in simulations
- Load sharing aligns with payload capabilities
- No explicit communication required among robots

## Abstract

This paper addresses the problem of cooperative object transportation for multiple Underwater Vehicle Manipulator Systems (UVMSs) in a constrained workspace with static obstacles, where the coordination relies solely on implicit communication arising from the physical interaction of the robots with the commonly grasped object. We propose a novel distributed leader-follower architecture, where the leading UVMS, which has knowledge of the object's desired trajectory, tries to achieve the desired tracking behavior via an impedance control law, navigating in this way, the overall formation towards the goal configuration while avoiding collisions with the obstacles. On the other hand, the following UVMSs estimate the object's desired trajectory via a novel prescribed performance estimation law and implement a similar impedance control law. The feedback relies on each UVMS's force/torque measurements and no explicit data is exchanged online among the robots. Moreover, the control scheme adopts load sharing among the UVMSs according to their specific payload capabilities. Finally, various simulation studies clarify the proposed method and verify its efficiency.