Jean-Daniel Nicoud

Toward indoor flying robots

Developing a research autonomous plane for flying in a laboratory space is a challenge that forces one to understand the specific aerodynamic, power and construction constraints. In order to obtain a very slow flight while maintaining a high maneuverability, ultralight structures and adequate components are required. In this paper we analyze the wing, propeller and motor characteristics and propose a methodology to optimize the motor/gear/propeller system. The C4 model plane (50g, 1.5m/s) demonstrates the feasibility of such a laboratory flying test-bed.

A 10-gram vision-based flying robot

We aim at developing ultralight autonomous microflyers capable of freely flying within houses or small built environments while avoiding collisions. Our latest prototype is a fixed-wing aircraft weighing a mere 10 g, flying around 1.5 m/s, and carrying the necessary electronics for airspeed regulation and lateral collision avoidance. This microflyer is equipped with two tiny camera modules, two rate gyroscopes, an anemometer, a small microcontroller and a Bluetooth radio module. In-flight tests were carried out in a new experimentation room specifically designed for easy changing of surrounding textures.

A 10-gram Microflyer for Vision-based Indoor Navigation

We aim at developing ultralight autonomous microflyers capable of navigating within houses or small built environments. Our latest prototype is a fixed-wing aircraft weighing a mere 10 g, flying below 2 m/s and carrying the necessary electronics for airspeed regulation and obstacle avoidance. This microflyer is equipped with two tiny camera modules, two rate gyroscopes, an anemometer, a small microcontroller, and a Bluetooth radio module. In-flight tests are carried out in a new experimentation room specifically designed for easy changing of surrounding textures.

DESIGN, CONTROL, AND APPLICATIONS OF AUTONOMOUS MOBILE ROBOTS

An autonomous robot is a machine that operates in a partially unknown and unpredictable environment. In contrast to robots used in manufacturing plants, where the environment is highly controlled, autonomous robots cannot always be programmed to execute predefined actions because one does not know in advance what will be the universe of required sensorimotor transformations required by the various situations that the robot might encounter. Furthermore, the environment might have dynamic characteristics that require rapid online modifications in the robot behaviour. For these reasons, in the last ten years several researchers have looked at novel methods for setting up autonomous mobile robots.

Microengineering: when is small too small? Nanoengineering: when is large too large?

Miniaturization, as exemplified by watches, was initially required for convenience. Cost-effectiveness was the drive for computer peripherals. New applications now push the research into microengineering and nanotechnologies. Mimicking animals has always been the dream of mobile robot builders. Nature has however developed extraordinary solutions for energy storage, scalable muscles with sizes down to few microns in diameter, multitudes of sensitive sensors and efficient distributed control mechanisms. Reducing the robots size make them more appropriate to study collective behaviour, but at some point the intelligence must be reduced. Below one cubic centimeter, there is even no solution to just make the robot move autonomously. Nanotechnology open the door to smaller sensors and motors have been built in the 100 micron range. These motors are far from performing reliably, their control electronics are cumbersome and the assembly is critical. The artificial insect is not yet for tomorrow.

A 1.5g SMA-actuated Microglider looking for the Light

Unpowered flight can be used in microrobotics to overcome ground obstacles and to increase the traveling distance per energy unit. In order to explore the potential of goal-directed gliding in the domain of miniature robotics, we developed a 22cm microglider weighing a mere 1.5g and flying at around 1.5m/s. It is equipped with sensors and electronics to achieve phototaxis, which can be seen as a minimal level of control autonomy. A novel 0.2g shape memory alloy (SMA) actuator for steering control has been specifically designed and integrated to keep the overall weight as low as possible. In order to characterize autonomous operation of this robot, we developed an experimental setup consisting of a launching device and a light source positioned lm below and 4m away with varying angles with respect to the launching direction. Statistical analysis of 36 autonomous flights demonstrate its flight and phototaxis efficiency.

Technology and Fabrication of Ultralight Micro-Aerial Vehicles

Recent advances in micro-air vehicles have produced impressive results for platforms weighing below 50 g. The lightest platforms to take flight with a minimum of functionality are below 0.5 g, but researchers dream of flying at insect size. However, many difficulties occur when scaling down existing technologies. Aerodynamic laws equate to decreased efficiency at smaller sizes and hence more power per weight is required. Current energy storage technologies do not have the required capacity and powertrains are no longer efficient enough. Construction is difficult due to small size and low weight requirements. This chapter surveys the status of current technology and its prospects in miniaturization and shows several examples to illustrate the state of the art and the difficulties in reaching ever-smaller platform sizes.

REYSM, a high performance, low power multi-processor bus

In order to build lower cost multimicroprocessor systems, a narrow synchronous bus (15 active lines) is proposed. It multiplexes address and data on 8 bits, and arbitrates in two pipe-lined cycles on four lines. Due to the 20 to 40 MHz bus clock, and the pipelined control logic, the performances are equivalent to Multibus-2, IEEE-P896 and similar 32-bit buses. For the implementation, cards are disposed radially around a special connector. The very short connections allows for the usage of fast HC-MOS drivers with only a light adaptation.

From Wheels to Wings with Evolutionary Spiking Circuits

I will give an overview of the EPFL indoor flying project, whose goal is to evolve neural controllers for autonomous, adaptive, indoor micro-flyers. Indoor flight is still a challenge because it requires miniaturization, energy efficiency, and control of non-linear flight dynamics. This ongoing project consists in developing a flying, vision-based micro-robot, a bio-inspired controller composed of adaptive spiking neurons directly mapped into digital micro-controllers, and a method to evolve such a neural controller without human intervention. The talk describes the motivation and methodology used to reach our goal as well as the results of a number of preliminary experiments on vision-based wheeled and flying robots.