324 research outputs found
Wake-Based Locomotion Gait Design for Aerobat
Flying animals, such as bats, fly through their fluidic environment as they
create air jets and form wake structures downstream of their flight path. Bats,
in particular, dynamically morph their highly flexible and dexterous armwing to
manipulate their fluidic environment which is key to their agility and flight
efficiency. This paper presents the theoretical and numerical analysis of the
wake-structure-based gait design inspired by bat flight for flapping robots
using the notion of reduced-order models and unsteady aerodynamic model
incorporating Wagner function. The objective of this paper is to introduce the
notion of gait design for flapping robots by systematically searching the
design space in the context of optimization. The solution found using our gait
design framework was used to design and test a flapping robot
A CFD-informed quasi-steady model of flapping-wing aerodynamics
Aerodynamic performance and agility during flapping flight are determined by the combination of wing shape and kinematics. The degree of morphological and kinematic optimization is unknown and depends upon a large parameter space. Aimed at providing an accurate and computationally inexpensive modelling tool for flapping-wing aerodynamics, we propose a novel CFD (computational fluid dynamics)-informed quasi-steady model (CIQSM), which assumes that the aerodynamic forces on a flapping wing can be decomposed into quasi-steady forces and parameterized based on CFD results. Using least-squares fitting, we determine a set of proportional coefficients for the quasi-steady model relating wing kinematics to instantaneous aerodynamic force and torque; we calculate power as the product of quasi-steady torques and angular velocity. With the quasi-steady model fully and independently parameterized on the basis of high-fidelity CFD modelling, it is capable of predicting flapping-wing aerodynamic forces and power more accurately than the conventional blade element model (BEM) does. The improvement can be attributed to, for instance, taking into account the effects of the induced downwash and the wing tip vortex on the force generation and power consumption. Our model is validated by comparing the aerodynamics of a CFD model and the present quasi-steady model using the example case of a hovering hawkmoth. This demonstrates that the CIQSM outperforms the conventional BEM while remaining computationally cheap, and hence can be an effective tool for revealing the mechanisms of optimization and control of kinematics and morphology in flapping-wing flight for both bio-flyers and unmanned aerial systems
Neurobiologically Inspired Control of Engineered Flapping Flight
This article presents a new control approach for engineered
flapping flight with many interacting degrees of freedom. This paper explores the applications of neurobiologically
inspired control systems in the form of Central Pattern Generators (CPG) to generate wing trajectories for potential flapping flight MAVs. We present a rigorous mathematical and control theoretic framework to design complex three dimensional motions of flapping wings. Most
flapping flight demonstrators are mechanically limited in generating the wing trajectories. Because CPGs lend themselves to more biological examples of flight, a novel
robotic model has been developed to emulate the flight of bats. This model has shoulder and leg joints totaling 10 degrees of freedom for control of wing properties. Results of wind tunnel experiments and numerical simulation of CPG-based flight control validate the effectiveness of the proposed neurobiologically inspired control approach
A hybrid dynamic model for bio-inspired soft robots - Application to a flapping-wing micro air vehicle.
International audienceThe paper deals with the dynamic modeling of bio-inspired robots with soft appendages such as flying insect-like or swimming fish-like robots. In order to model such soft systems, we propose to use the Mobile Multibody System framework introduced in [1][2][3]. In such a framework, the robot is considered as a tree-like structure of rigid bodies where the evolution of the position of the joints is governed by stress-strain laws or control torques. Based on the Newton-Euler formulation of these systems, we propose a new algorithm able to compute at each step of a time loop both the net and passive joint accelerations along with the control torques supplied by the motors. To illustrate, based on previous work [4], the proposed algorithm is applied to the simulation of the hovering flight of a soft flapping-wing insect-like robot (see the attached video)
Integration of Polyimide Flexible PCB Wings in Northeastern Aerobat
The principal aim of this Master's thesis is to propel the optimization of
the membrane wing structure of the Northeastern Aerobat through origami
techniques and enhancing its capacity for secure hovering within confined
spaces. Bio-inspired drones offer distinctive capabilities that pave the way
for innovative applications, encompassing wildlife monitoring, precision
agriculture, search and rescue operations, as well as the augmentation of
residential safety. The evolved noise-reduction mechanisms of birds and insects
prove advantageous for drones utilized in tasks like surveillance and wildlife
observation, ensuring operation devoid of disturbances. Traditional flying
drones equipped with rotary or fixed wings encounter notable constraints when
navigating narrow pathways. While rotary and fixed-wing systems are
conventionally harnessed for surveillance and reconnaissance, the integration
of onboard sensor suites within micro aerial vehicles (MAVs) has garnered
interest in vigilantly monitoring hazardous scenarios in residential settings.
Notwithstanding the agility and commendable fault tolerance exhibited by
systems such as quadrotors in demanding conditions, their inflexible body
structures impede collision tolerance, necessitating operational spaces free of
collisions. Recent years have witnessed an upsurge in integrating soft and
pliable materials into the design of such systems; however, the pursuit of
aerodynamic efficiency curtails the utilization of excessively flexible
materials for rotor blades or propellers. This thesis introduces a design that
integrates polyimide flexible PCBs into the wings of the Aerobat and employs
guard design incorporating feedback-driven stabilizers, enabling stable
hovering flights within Northeastern's Robotics-Inspired Study and
Experimentation (RISE) cage.Comment: 42 pages,20 figure
Modeling and Simulation of Nonlinear Dynamics of Flapping Wing Micro Air Vehicles
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90638/1/AIAA-54288-189.pd
Principle Of Bio-Inspired Insect Wing Rotational Hinge Design
A principle for designing and fabricating bio-inspired miniature artificial insect flapping wing using flexure rotational hinge design is presented. A systematic approach of selecting rotational hinge stiffness value is proposed. Based on the understanding of flapping wing aerodynamics, a dynamic simulation is constructed using the established quasi-steady model and the wing design. Simulations were performed to gain insight on how different parameters affect the wing rotational response. Based on system resonance a model to predict the optimal rotational hinge stiffness based on given wing parameter and flapping wing kinematic is proposed. By varying different wing parameters, the proposed method is shown to be applicable to a wide range of wing designs with different sizes and shapes. With the selected hinge stiffness value, aspects of the rotational joint design is discussed and an integrated wing-hinge structure design using laminated carbon fiber and polymer film is presented. Manufacturing process of such composite structure is developed to achieve high accuracy and repeatability. The yielded hinge stiffness is verified by measurements. To validate the proposed model, flapping wing experiments were conducted. A flapping actuation set up is built using DC motor and a controller is implemented on a microcontroller to track desired wing stroke kinematic. Wing stroke and rotation kinematic were extracted using a high speed camera and the lift generation is evaluated. A total of 49 flapping experiments were presented, experimental data shows good correlation with the model\u27s prediction. With the wing rotational hinge stiffness designed so that the rotational resonant frequency is twice as the stroke frequency, the resulting wing rotation generates near optimal lift. With further simulation, the proposed model shows low sensitivity to wing parameter variation. As a result, giving a design parameter of a flapping wing robot platform, the proposed principle can predict the rotational hinge stiffness that leads to near optimal wing rotation. Further iteration can be done around the selected value and achieve the optimal lift generation
DESIGN AND CONTROL OF A HUMMINGBIRD-SIZE FLAPPING WING MICRO AERIAL VEHICLE
Flying animals with flapping wings may best exemplify the astonishing ability of natural selection on design optimization. They evince extraordinary prowess to control their flight, while demonstrating rich repertoire of agile maneuvers. They remain surprisingly stable during hover and can make sharp turns in a split second. Characterized by high-frequency flapping wing motion, unsteady aerodynamics, and the ability to hover and perform fast maneuvers, insect-like flapping flight presents an extraordinary aerial locomotion strategy perfected at small size scales. Flapping Wing Micro Aerial Vehicles (FWMAVs) hold great promise in bridging the performance gap between engineered flying vehicles and their natural counterparts. They are perfect candidates for potential applications such as fast response robots in search and rescue, environmental friendly agents in precision agriculture, surveillance and intelligence gathering MAVs, and miniature nodes in sensor networks
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