Free Flying Micro Platform and Papa-TV-Bot:
evolving autonomously hovering mobots
The Media Laboratory
Massachusetts Institute of Technology
20 Ames Street, Cambridge, MA USA 02139
Notes: The author has written a more recent and extensive paper about FFMPs that includes this paper. There is also a website about a prototype. Back to the Free Flying Micro Platform (FFMP) and Papa-TV-Bot homepage.
2 Scenario Papa-TV-Bot
4 Basic technologies of vehicles of the Phases 1 through 3
4.1 Phase 1
4.1.1 Sensors and controlling
4.1.3 Batteries and power transmission
4.2 Phase 2
4.3 Phase 3
This paper outlines the possibilities, the evolution, and the basic technical elements of autonomously hovering micro robots. It consists of three parts. The first part presents the application Papa-TV-Bot, a free flying automatic video camera. The second part is a schedule for the long-term development of autonomously hovering mobots1 in 8 phases. The third part describes the basic technologies of the vehicles of Phases 1 through 3.
It is well known that entities heavier than air cannot stand still in the air without the help of propulsion engines. The only machines capable of free hovering are helicopters2 . Their ability to move freely in 3-dimensional space  makes them important not only for transport but also for looking at the world from unusual viewpoints3. This is especially interesting for television and video productions. Aerial video- and photography is also conducted through unmanned vehicles, such as remote controlled helicopters (e.g., [3,11,17,44,47]). Although the size of these vessels is only about 3 to 5 feet in diameter, they are too dangerous for indoor use because of their large, exposed rotors. Additionally, most of them use noisy and grimy combustion engines. Due to their underlying mechanical principles, they are fundamentally unstable with highly nonlinear dynamics [28,23,24].
For these reasons, aerial photography using model helicopters is limited to expert pilots in outdoor environments, and cannot be conducted near or over crowds of people. Nevertheless, these camera positions would be interesting for TV productions  of entertainment shows like concerts and sports events. Cameras hovering over an open field, taking shots from directly above the audience, could convey thrilling pictures. Another interesting domain for these vehicles would be hazards of all kinds, such as radiated areas, hostage situations, and structurally unstable buildings into which it is too dangerous to send humans.
In the first part of this paper, I present a scenario with a Papa-TV-Bot. The second part is a schedule for the long-term development of autonomously hovering mobots in 8 phases, starting with a simple Free Flying Micro Platform (FFMP), developed into a Papa-TV-Bot, then into a hyper-intelligent zero-gravity mobot with multi-ethical awareness. In the third part, I describe the basic technologies of a vehicle of the first three phases, the Free Flying Micro Platform (FFMP), in more detail. It is a Micro Air Vehicle (MAV, [5858>,35]), "a tiny, self-piloted flying machine," neither bird nor plane, but "it's a little of both with some insect and robot characteristics thrown in" . Therefore, compared to today’s R/C helicopters  it is smaller (diameter less than 10 inches), quieter (electro motors), safer (rotors hidden in the fuselage), and—most important—it can hover automatically.
How does the world look through the eyes of a humming bird? Imagine a basketball game: You watch the players from an altitude of twenty feet and then—within seconds—see them from three inches above the court floor. Then you follow the player with the ball across the whole court, always exactly one foot above his shoulder. You pass him and climb up quickly to one inch above the basket, right in time for the slam.
The device that could deliver these unusual camera perspectives is a 5-inch autonomous rotary-wing MAV with a video camera and wireless transmission. Four electric ducted fans and an absolute position sensor enable it to hover automatically. After it is switched on, the mobot automatically stabilizes itself in the air, so that it stays where it was put. To move it away from this initial position, one can use simple voice commands such as up, down, left, and right, spoken directly towards the vehicle, or through a walkie-talkie-like communication device. It also accepts more complicated verbal mission requests like "Follow this person at a distance of 8 feet and an altitude of 5 feet." Because such a video surveillance activity resembles Paparazzi photographers, the appropriate name for this device is Papa-TV-Bot: Paparazzi Television Mobot. To reduce the annoying effects of such a "flying spy camera," another set of intuitive voice commands, like go away, let it immediately move away from the speaker. Additionally, it must
- Avoid obstacles. If a human or non-human object obstructs the MAV during its filming missions, it must try to fly around it (e.g., ).
- Evade capture. Due to its purpose of approaching objects very closely and flying over crowds of people, it has to evade somebody trying to catch it.
- Be Safe. Because a Papa-TV-Bot is supposed to operate above people, it has to have extensive safety mechanisms. In case of failure of engines or electronics, or if the remote emergency kill-switch is pressed, four gas filled airbags are inflated instantaneously and cover most of the surface of the inoperational vessel. Equipped with these protective airbags, it falls back to earth without causing any harm.
In order to reach the sophisticated level of a Papa-TV-Bot, I propose to develop and evolve autonomously hovering mobots gradually. For this purpose, I have defined 8 distinctive phases. In each phase, certain features and abilities are added to the characteristics of the previous phases:
Table 1 outlines the main goals, primary motivations, as well as the important domains of each phase.
- Phase 1: Free flying micro platform (FFMP) for studying helicopter control, automatic control systems, and automatic hovering.
- Phase 2: Flying camera: for indoor aerial video, and fast and uncomplicated Electronic News Gathering (ENG) tasks.
- Phase 3: Listening mobot: direct voice communication with a mobot.
- Phase 4: Mobot with crude situational awareness through its sensors, good for more complex ENG tasks. Due to their autonomy, several mobots per cameraman are possible.
- Phase 5: Mobot that understands complex spoken language and has refined situational awareness: intelligent autonomous micro video camera with maximum degrees of freedom.
- Phase 6: Mobot that learns from experience: the longer it operates, the more efficiently it behaves.
- Phase 7: Self-repairing mobot, or mobots being able to repair each other.
- Phase 8: Truly intelligent and highly responsible mobot.