In this paper, we present the mechanical design of a compact magnetic wheeled robot - with the goal to do inspection and vibration measurements in the housings of large generators and similar environments in power plants. After a detailed analysis of the specifications in this application, we present a new vehicle structure that allows for passing sharp concave corners - even with low friction coefficient between wheels and surface - and without using an additional active DOF. The advantages of this structure and the core parameters for its optimization are described in a quasi-static 2D calculation model. A prototype was implemented and successfully tested both in laboratory and real environments. The paper concludes pointing out the future improvements for a final industrial version.

This paper describes a compact robot with two magnetic wheels in a bicycle arrangement, which is intended for inspecting the inner casing of pipes with complex shaped structures. The locomotion concept is based on an adapted magnetic wheel unit integrating two lateral lever arms. These arms allow for slightly lifting off the wheel in order to locally decrease the magnetic force, as well as laterally stabilizing the wheel unit. The robot has the main advantage to be compact and mechanically simple. It features 5 active degrees of freedom: 2 driven wheels each equipped with an active lifter-stabilizer and 1 steering unit. This paper also presents the design and implementation of a prototype robot and its high mobility is shown. It is able to pass 90deg convex and concave obstacles with any inclination regarding the gravity. Finally, it only requires limited space to maneuver, since turning on spot around the rear wheel is possible.

Magnetically compatible robots are required to develop haptic interfaces for neuroscience studies and MRI guided robots for minimally invasive interventions. This paper introduces an MR compatible master slave concept using a hydraulic transmission, and presents an operational robot able to work within an MRI/fMRI scanner and acquire images continuously during motion. It describes a magnetically inert actuator using a direct drive to power the hydraulic circuitry and a modular set of position and force/torque sensors that we have developed. These were integrated into a haptic interface prototype with on rotary degree of freedom, which can be used in conjuction with an fMRI. The MR compatibility was confirmed experimentally, and the performances show a manipulation accuracy of a few micrometers over a range of several centimeters, and forces up to several thousand Newton.