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Ph.D. Thesis Proposal by
Dr. Panagiotis Tsiotras (Advisor)
May 10th @ 4:00 pm
Montgomery Knight Room 317
Abstract:
As of 2014, the space servicing market has a potential revenue of $3-$5B per year due to the ever-present interest to upkeep existing orbiting infrastructure. In space servicing, there is a delicate balance between system complexity and servicer capability. Basic module-exchange servicers decrease the complexity of the servicing spacecraft, but is likely to require a more complex architecture of the serviced satellite (the host) in terms of electrical and mechanical connections.
With increasing dexterity of the servicing satellite, host satellites can remain closer to flight-proven heritage architectures, which is a practice commonly adopted to increase reliability of space missions. This increased dexterity can be provided through the on-orbit exchange of end-effector tools appended to a robotic arm. The dynamic coupling of the arm and the base has been the subject of intense academic scrutiny and its understanding is essential to the implementability and success of robotic servicing missions.
In this work, we propose a framework to implement the different phases of a servicing mission based on dual quaternion algebra. First, we propose a dual quaternion 6-{DOF} pose-tracking controller that adaptively estimates the mass properties of a spacecraft using the concurrent learning framework. Next, we provide a generalizable case study of the derivation of the dynamic equations of motion for a spacecraft with a serial robotic manipulator. This derivation uses a Netwon-Euler approach, and its results are validated against an analogous derivation that uses a decoupled representation of translational and rotational dynamics
Future work will include the generalization of this framework to contain [endif]--> robotic arms with [endif]--> links. Additionally, for the case of a one-arm system, a pose-stabilizing controller of the end-effector will be proposed in the context of differential dynamic programming, as well as a pose-tracking controller that will follow the concept of control-computed torque. The results will then be used to simulate the autonomous rendezvous and capture of an orbiting object. Finally, an algorithm will be proposed to estimate the mass properties of said captured object.
Committee Members:
