Boeing Confined Assembly Project
Project Overview	The aeronautics industry requires riveting operations inside enclosed sections of aircraft assemblies which are already mostly constructed. Human labor it an unattractive option for this task, as the cramped ergonomic conditions make riveting both inefficient and difficult for the workers. Conventional robots are not an option, as they cannot fit through the limited access ports. Therefore, we are construction a redundant mechanism that utilizes many degrees of freedon to reach inside the structure and deliver tooling to key locations. The project has two main focuses: The mechanical design of a redundant arm capable of delivering a heavy payload accurately into a confined space. Developing kinematic methods to handle the task's unique constraints
Mechanical Design	The design of our arm mimics SCARAs, with links configured so they fold on top of each other in order to be inserted through a limited access port. This video illustrates the concept.
	This requires the development of a high strength, yet lightweight, robot. We have designed modular joint assemblies using several special parts, uncluding harmonic drives and high torque ring motors. A prototype joint has been tested for strength and accuracy. The first video below is a preliminary load test, where the joint is supporting an overturning moment of 35lbs at 3ft. The joint has since been sucessfully tested up to 80lbs at 3ft. The second video is a excerpt from some accuracy testing. In order to compensate for the deflection and oscillation of such a flexible arm, we are developing fine positioning modules to brace the end effector on the working surface, to position it within .010" of the target goal.
Kinematic Planning	The task and workspace present some some unique problems. The arm must operate in several different size enclosures, so the result is a redundant mechanism which can only use a portion of its total joints at any one time to complete end effector motion. We have developed an Adaptive Jacobian method in order to complete our path planning under such unpredictable constraints. Those interested may read further here and here.
	This video is some output from a simulation of the arm accessing different target areas of the enclosure.
Last edited 10/20/06