We proposed an RL framework for control of flapping-wing MAVs (2006). The algorithm has been discussed and simulation results using a quasi-steady model showed initial promise. In this paper, the results from an experiment on a Drosophila-based dynamically scaled model are presented and are used to verify the control framework. Moreover, a comparison between a biological Drosophila melanogaster and the experimental results shows the actual possibility of employing the proposed approach to MAV control problem

Flapping micro aerial vehicles are interesting in applications where maneuverability is needed in confined spaces. Yet aerodynamics of insect flapping flight is not completely known and the research in this area lacks a suitable aerodynamic model that can be used for control purposes. Reinforcement learning approach is proposed which is inspired from "how" the learning is achieved in real insects in nature. The reinforcement learning controller has been simulated using a quasi-steady aerodynamic model and shown to converge to a flapping motion. The learning capacity and advantages of this approach are also discussed

Insect sensors are fascinating for their simplicity in design, efficiency in function, and robustness to variable environments. Many engineering applications would benefit from these features, therefore, much research, especially recently in biorobotics, has focused on biomimetic sensors. However, human engineering ingenuity still falls short in comparison to nature's capabilities. This research area is inherently multidisciplinary in nature, calling for collaboration from biologists, neurologists and engineers. This paper is intended to provide an insight into force sensor design for microflight based on current biological, biomimetic and miniature sensors available to compare existing attempts and to make a framework to identify issues that need further attention. This review covers recent experiments concerning the sensor design, as well as different key works in this area. The limitations and scaling issues with some of these methods are explored.

This paper presents some recent improvements in the fabrication and control of the micromechanical flying insect (MFI), a centimeter sized aerial vehicle currently being developed at the University of California, Berkeley. We report a lift of 506 /spl mu/N from a single wing, which is sufficient for a 100 mg machine to lift itself off the ground. This lift matches very well with predictions based on quasi steady state models. We present some recent improvements in thorax fabrication leading to the development of a light weight platform (/spl sim/ 100 mg), which generates 400 /spl mu/N of lift with a single wing. We also present a new sensor mechanism, which makes it possible to sense the motion of the actuators without having to add anything to the structure itself.

The first force map has been generated for a 2 DOF wing designed for the MFI project. For the wing beating at a resonance frequency of 139 Hz, the average 3-D forces were found as a function of sinusoidal voltage amplitude and actuator phase difference. An image sequence of the wing trajectory allowed comparison to simulated forces using a quasi-steady state aerodynamic approximation. Finally, the results were compared to the case of ideally matched leading/lagging wing dynamics driven by sinusoids.

This paper focuses on the design, fabrication and characterization of unimorph actuators for a microaerial flapping mechanism. PZT-SH and PZN-PT are investigated as piezoelectric layers in the unimorph actuators. Design issues for microaerial flapping actuators are discussed, and criteria for the optimal dimensions of actuators are determined. For low power consumption actuation, a square wave based electronic driving circuit is proposed. Fabricated piezoelectric unimorphs are characterized by an optical measurement system in quasi-static and dynamic mode. Experimental performance of PZT-5H and PZIV-PT based unimorphs is compared with desired design specifications. A 1-DOF flapping mechanism with a PZT-SH unimorph is constructed, and 180/spl deg/ stroke motion at 95 Hz is achieved. Thus, it is shown that unimorphs could be promising flapping mechanism actuators.

Considers a 2 DOF resonant thorax structure signed and fabricated for the MFI project. Miniature piezoelectric PZN-PT unimorph actuators were fabricated and used to drive a four-bar transmission mechanism. The current thorax design utilizes two actuated four-bars and a spherical joint to drive a rigid wing. Rotationally compliant flexure joints have been tested with lifetimes over 10/sup 6/ cycles. Wing spars were instrumented with strain gauges for force measurement and closed-loop wing control.

Flapping wings provide unmatched manoeuvrability for flying microrobots. Recent advances in modelling insect aerodynamics show that adequate wing rotation at the end of the stroke is essential for generating adequate flight forces. We developed a thorax structure using four bar frames combined with an extensible fan-fold wing to provide adequate wing stroke and rotation. Flow measurements on a scale model of the beating wing show promising aerodynamics. Calculations using a simple resonant mechanical circuit model show that piezoelectric actuators can generate sufficient power, force and stroke to drive the wings at 150 Hz.

This paper presents design aspects of a force-reflecting, motion-scaling teleoperation system for use in microsurgery experiments. A coarse-macro-micro approach is proposed. Two magnetically levitated wrists-a macro-master and a micro-slave-would share a common base positioned at the surgical site by a coarse-motion transport robot. The discussion includes features of the proposed system, a detailed slave wrist description, and aspects of coordination and control for the multistage teleoperation.>