Cooperative Assembly with Autonomous Mobile Manipulators in an Underwater Scenario

[...] Specifically, the problem addressed is an assembly one known as the peg-in-hole task. In this case, two autonomous manipulators must carry cooperatively (at kinematic level) a peg and must insert it into an hole fixed in the environment. Even if the peg-in-hole is a well-known problem, there are no specific studies related to the use of two different autonomous manipulators, especially in underwater scenarios. Among all the possible investigations towards the problem, this work focuses mainly on the kinematic control of the robots. The methods used are part of the Task Priority Inverse Kinematics (TPIK) approach, with a cooperation scheme that permits to exchange as less information as possible between the agents (that is really important being water a big impediment for communication). A force-torque sensor is exploited at kinematic level to help the insertion phase. The results show how the TPIK and the chosen cooperation scheme can be used for the stated problem. The simulated experiments done consider little errors in the hole's pose, that still permit to insert the peg but with a lot of frictions and possible stucks. It is shown how can be possible to improve (thanks to the data provided by the force-torque sensor) the insertion phase performed by the two manipulators in presence of these errors. [...]