Cellulo: Versatile Handheld Robots for Education

In this article, we present Cellulo, a novel robotic platform that investigates the intersection of three ideas for robotics in education: designing the robots to be versatile and generic tools; blending robots into the classroom by designing them to be pervasive objects and by creating tight interactions with (already pervasive) paper; and finally considering the practical constraints of real classrooms at every stage of the design. Our platform results from these considerations and builds on a unique combination of technologies: groups of handheld haptic-enabled robots, tablets and activity sheets printed on regular paper. The robots feature holonomic motion, haptic feedback capability and high accuracy localization through a microdot pattern overlaid on top of the activity sheets, while remaining affordable (robots cost about EUR 125 at the prototype stage) and classroom-friendly. We present the platform and report on our first interaction studies, involving about 230 children

Optic Flow Regulation in Unsteady Environments: A Tethered MAV Achieves Terrain Following and Targeted Landing Over a Moving Platform

International audienceThe present study deals with the risky and daunting tasks of flying and landing in non-stationary environments. Using a two Degree-Of-Freedom (DOF) tethered micro-air vehicle (MAV), we show the benefits of an autopilot dealing with a variable - the optic flow - which depends directly on two relative variables, the groundspeed and the groundheight. The micro-helicopter was shown to follow the ups and downs of a rotating platform that was also oscillated vertically. At no time did the MAV know in terms of ground height whether it was approaching the moving ground or whether the ground itself was rising to it dangerously. Nor did it know whether its current groundspeed was caused only by its forward thrust or whether it was partly due to the ground moving backwards or forwards. Furthermore, the MAV was shown to land safely on a platform set into motion along two directions, vertical and horizontal. This paper extends to non-stationary environments a former approach that introduced the principle of ``optic flow regulation'' for altitude control. Whereas in the former approach no requirement was set on the robot's landing target, the target's elevation angle was used here in a second feedback loop that gradually altered the robot's pitch and therefore its airspeed, leading to smooth landing in the vicinity of the target. Whether dealing with terrain following or landing, the MAV followed followed appropriately the unpredictable changes in the environment although it had no explicit knowledge of groundheight and groundspeed. The MAV did not make use of any rangefinders or velocimeters and was simply equipped with a 2-gram vision-based autopilot

UNI-Copter: A portable single-rotor-powered spherical unmanned aerial vehicle (UAV) with an easy-to-assemble and flexible structure

This paper presents the design and modeling of the UNI-Copter, a portable spherical unmanned aerial vehicle (UAV) that is powered by a single rotor. This type of single-rotor spherical UAV has many advantages over other types of multi-rotor UAVs, but the spherical external structure takes up more volume, thereby reducing its portability. We focus on designing and building the UNI-Copter to provide ease of assembly and portability while taking advantage of the existing spherical structure. This paper explains our design concepts and the development process of improving the performance through various prototypes. We also verify flight stability of our new design by conducting several flight tests. To do so, a mathematical model of the UNI-Copter is derived in detail, and then we implement a state feedback controller for hovering flight. As a result, the indoor flight tests show stable performance, and the outdoor flight tests show that stable performance could also be achieved provided that the wind speed is low