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.

A passive mobile robot carrying a heavy manufacturing tool is activated from across a thin wall. The mobile robot placed within a confined space has no tether and no local battery, but is powered from an outside robot through magnetic coupling. A pair of magnetic feet allows the passive inside robot to hang from a ceiling and walk across a wall. A heavy manufacturing tool held in the middle of the passive inside robot is activated with a Lorentz force actuator-this is also activated from the outside robot. A set of Hall effect sensors on the outside robot detect the magnetic field created by the passive robot in order to estimate the position of the inside robot. First, the task conditions and functional requirements are described, and the design concept of the passive mobile robot is presented. An electro-magnetic model for predicting magnetic field strength and load bearing capacity is used to facilitate design as well as to estimate and control the position of the passive inside robot. A proof-of-concept prototype system is designed and built for application to aircraft manufacturing.

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.

The use of high performance composite materials provides a substantial performance improvement for microrobotics. Such materials have great benefits over common MEMs materials such as better fracture toughness and fatigue properties than semiconductors, and higher stiffness to weight ratios than most metals. Composite structures yield remarkable improvements in microrobotic links and joints, as well as greater performance actuators while allowing complicated microrobotic mechanisms to be easily rapid prototyped. The use of such materials in the construction of the 4DOF, 26 joint Micromechanical Flying Insect has reduced the thorax inertia by a factor of 3 and given a 20% increase in resonant frequency over previous designs while cutting construction time from weeks to days.