We present an initial design of a mobile robotic system for automated assembly inside an aircraft body. This system allows for the positioning control of a heavy duty end effector that is working on the far side of a thin wall at any orientation. It utilizes electromagnets to hold the end effector against the wall, as well as linear motor type actuation for locomotion.Initial testing on a prototype verifies the effectiveness of some of the chosen design parameters.
A pair of mobile robots acting on opposite sides of a thin plate is developed for a class of tasks where robots have to work together, carrying a pair of end-effectors and traversing across a plate surface. Using powerful magnets, the paired robots attract each other, support themselves against gravity, and generate traction force to move across the panel.First, the design concept of paired mobile robots is presented, followed by dynamic modeling and magnetic analysis. Conditions for preventing the robot from falling as well as from slipping on the plate surface are examined. Time-optimal control of the paired robots subject to the no-fall, no-slip conditions is formulated and solved numerically. Precision positioning control using a laser beacon is designed and tested. A prototype of the paired robots using Halbach array permanent magnets and Lorentz force actuators is developed, and the control methods are implemented and tested on the prototype.Note to Practitioners-The paired robot architecture presented here was inspired by aircraft wing box assembly, where two end-effectors, (one inside and the other outside), must be coordinated to tightly clamp a skin panel and perform precision drilling and fixing operations. This paper aims to automate this process with paired mobile robots that transport and align the two end-effectors anywhere on the aircraft wing. This will eliminate the need for scaffold and fixtures to support the end-effectors, since the paired mobile robots are attached directly to the aircraft body and position the end-effectors at desired locations. This paper presents the necessary analysis to be performed when applying this dual robot concept. We show how much force is necessary to support the paired robots against gravity and perform locomotion and fine positioning. We show that a special permanent arrangement, called the Halbach array, allows us to generate sufficient forces. We further discuss the complications of eddy currents, friction, and the whole system dynamics. It is shown that a prototype paired robot system can generate 1000 N of attractive force and achieve high positioning accuracy of less than 100 um of error. Potential applications include tank or pipe inspection, ship building, or general sheet metal manufacturing processes.
This paper describes the development of an articulating endoscopic screw driver that can be used to place screws in osteosynthetic plates during thoracoscopic surgery. The device is small enough to be used with a 12 mm trocar sleeve and transmits sufficient torque to fully secure bone screws. The articulating joint enables correct screw alignment at obtuse angles of up to 60 deg from the tool axis. A novel articulating joint is presented, wherein a flexible shaft both transmits torque and actuates the joint; antagonist force is provided by a superelastic spring. Screws are secured against the driver blade during insertion and with a retention mechanism that can passively release the screw when it has been securely placed in the bone. The prototype has been fitted with a blade compatible with 2.0 mm and 2.3 mm self-drilling screws although a different driver blade or drill bit can easily be attached. Efficacy of the tool is demonstrated by securing an osteosynthetic plate to a rib in a mock surgical setup. This tool enables minimally invasive, thoracoscopic rib fixation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.