Miniature Quad-rotor Dynamics Modeling & Guidance for Vision-based Target Tracking Control Tasks

This paper presents the dynamics modeling and the control & guidance architecture for specific target tracking indoors tasks using a miniature quad-rotor. Our objective is to develop a testbed using Matlab for experimentation and simulation of dynamics, control and guidance methods within a strong interplay between the hardware on board and software provisioned

Robust Control of Flapping-Wing in Micro Aerial Vehicle to have a Smooth Flapping Motion

This paper in first sections, will give a brief overview of both the purpose and the challenges facing the actuator and structure of Micromechanical Flying Insects (MFIs) and, in the last sections, an appropriate controller will developed for flapping motion. A hierarchical architecture that divides the control unit into three main levels is introduced. This approach break a complex control problem into a multi-level set of smaller control schemes, each of which is responsible for a clearly defined task. Also, the controller at each level can be designed independently of those in other levels. A fourbar mechanism for the wing displacement amplification, and a new system for fourbar mechanism actuation (wing actuation) is developed. We will develop a flexible beam with piezoelectric actuators and sensor (called Smart Beam) that will used to excite the fourbar mechanism for flapping mode of flight. The Frequency Response Function (FRF) of the smart beam was obtained from a Finite Element (FE) model and experimental system identification. The corresponding transfer function was derived from the mu synthesis and several robust controllers were then designed to control the beam to reach a smooth flapping motion. Besides excitation of the fourbar mechanism, the Smart beam will be used to control of noise and disturbance in the structure of the wing system

Locomotion response of airborne, ambulatory and aquatic insects to thermal stimulation using piezoceramic microheaters

This paper reports the locomotion response of airborne, ambulatory and aquatic insects to thermal stimulation. A finite element model has been developed to predict the variation of insect–stimulator interface temperature with input power. Piezothermal stimulators have been fabricated from lead zirconate titanate (PZT) using a batch mode micro ultrasonic machining process. Typical sizes range from 200 µm to 3.2 mm. For PZT stimulators, the temperature and thermal efficiency reach the maximum value around the resonance frequency which is typically in the range of 650 kHz to 47 MHz. Experiments have been conducted on green June beetles (GJBs), Madagascar hissing roaches and green diving beetles (GDBs) in order to show the versatility of the proposed technique. The stimulators have been implanted near the antennae of the GJBs and on either side of the thorax of the Madagascar hissing roaches and GDBs, respectively. In all cases, the insects move away from the direction of the actuated stimulator. The left and right turns are statistically similar. Thermal stimulation achieves an overall success rate of 78.7%, 92.8% and 61.6% in GJBs, roaches and GDBs, respectively. On average, thermal stimulation results in an angle turn of about 13.7°–16.2° on GJBs, 30°–45° on the roaches and 30°–50° on GDBs. The corresponding average input power is 360, 330 and 100 mW for GJBs, roach and GDBs, respectively. Scaling limits of the PZT stimulators for operating these stimulators are also discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90797/1/0960-1317_21_12_125002.pd

Dynamical systems analysis of electrostatic and aerodynamic forced vibrations of a thin flexible electrode

Transverse vibrations of an electrostatically actuated thin flexible cantilever perturbed by low-speed air flow is studied using both experiments and numerical modeling. In the experiments the dynamic characteristics of the cantilever are studied by supplying a DC voltage with an AC component for electrostatic forcing and a constant uniform air flow around the cantilever system for aerodynamic forcing. The maximum voltage applied varies from 1 - 9 kV and air flow speeds range from 0.224 - 3.58 m/s (0.5 - 8 mile/hr). The Reynolds numbers for these speeds lie in the range of 1000 - 20000. A range of control parameters leading to stable vibrations are established using the Strouhal number as the operating parameter whose inverse values change from 100 - 2500. The Numerical results are validated with experimental results. Assuming the amplitude of vibrations are small, then a non-linear dynamic Euler-Bernoulli beam equation with viscous damping and gravitational effects is used to model the vibrations of the dynamical system. Aerodynamic forcing is modeled as a temporally sinusoidal and uniform force acting perpendicular to the beam length. The forcing amplitude is found to be proportional to square of air flow velocity by obtaining relationship between the experimental amplitude of vibrations and air flow velocity. Numerical results strongly agree with those of experiments predicting accurate vibration amplitudes, displacement frequency and quasi-periodic displacements of the cantilever tip

Design of a flapping mechanism for reproducing the motions at the base of a dragonfly wing

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (p. 48-49).Insect flight is being studied to aid in the development of micro-air vehicles that use the flapping wing model in an attempt to achieve the high levels of maneuverability that insects have. The flight of the dragonfly has been chosen to be modeled because of its exceptional flight capabilities. This thesis addresses the flapping mechanism designed for the root of each wing. The prototype of the mechanism, built at a scale of four times the size of a dragonfly having a wingspan of 150 mm, is able to create motions in the wing of flapping and feathering, and can vary the stroke plane. The coning angle can be set between tests. The design process began with considering two methods of actuation, a four-bar transmission mechanism used in the Micromechanical Flying Insect developed in the UC Berkeley Biomimetic Millisystem Lab, and by pivoting the wing support directly with cables or rigid links. The second design was chosen to be developed further. A functional prototype was built from acrylic and parts made using stereolithography.by Teresa Liu.S.B

Resilient Opportunistic On-line Global Optimization

Abstract Traditional off-line global optimization is non-resilient and non-opportunistic. That is, traditional global optimization is unresponsive to small perturbations of the objective function that require a small or large change in the optimizer. On-line optimization methods that are more resilient and opportunistic than their off-line counterparts typically consist of the computationally expensive sequential repetition of off-line techniques. A novel approach to on-line global optimization is to utilize the theory of evolutionary generation systems to develop a technique that is resilient, opportunistic, and inexpensive. The theory of evolutionary generation systems utilizes the probabilistic sequential selection of a candidate optimizer from two possible candidates, basing the selection on the ratio of the fitness values of the candidates and a parameter called the level of selectivity. Using time-homogeneous, irreducible, ergodic Markov chains to model a sequence of local, and hence inexpensive, decisions, this paper proves that such decisions result in the resilient and opportunistic determination of a candidate optimizer for a given objective function. In the limit as the level of selectivity tends to infinity, the theory guarantees that the candidate optimizer is a global optimizer. The optimization of flapping wing gaits illustrates the theory

Design optimization of small-scale unmanned air vehicles

Ph.DDOCTOR OF PHILOSOPH

Towards MAV Autonomous Flight: A Modeling and Control Approach

This thesis is about modeling and control of miniature rotary-wing flying vehicles, with a special emphasis on quadrotor and coaxial systems. Mathematical models for simulation and nonlinear control approaches are introduced and subsequently applied to commercial aircrafts: the DraganFlyer and the Hummingbird quadrotors, which have been hardware-modified in order to perform experimental autonomous flying. Furthermore, a first-ever approach for modeling commercial micro coaxial mechanism is presented using a flying-toy called the Micro-mosquito