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

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

Experimental Characterization of the Structural Dynamics and Aero-Structural Sensitivity of a Hawkmoth Wing Toward the Development of Design Rules for Flapping Wing Micro Air Vehicles

A case is made for why the structures discipline must take on a more central role in the research and design of flapping-wing micro-air-vehicles, especially if research trends continue toward bio-inspired, insect-sized flexible wing designs. In making the case, the eigenstructure of the wing emerges as a key structural metric for consideration. But with virtually no structural dynamic data available for actual insect wings, both engineered and computational wing models that have been inspired by biological analogs have no structural truth models to which they can be anchored. An experimental framework is therefore developed herein for performing system identification testing on the wings of insects. This framework is then utilized to characterize the structural dynamics of the forewing of a large sample of hawkmoth (Manduca Sexta) for future design and research consideration. The research also weighs-in on a decade-long debate as to the relative contributions that the inertial and fluid dynamic forces acting on a flapping insect wing have on its deformation (expression) during flight. Ultimately the findings proves that both affect wing expression significantly, casting serious doubt on the longstanding and most frequently cited research that indicates fluid dynamic forces have minimal or negligible effect

Efficacy of Flapping-wing Flight Via Dual Piezoelectric Actuation

A novel piezoelectric-actuated wing system featuring dual actuators for increased wing control is presented and evaluated for its forward-flight characteristics via theoretical modeling and physical wind tunnel testing. Flapping wing aerial systems serve as a middle ground between the traditional fixed-wing and rotary systems. Flapping wing aerial systems exhibit high maneuverability and stability at low speeds (like rotary systems) while maintaining increased efficiency (like fixed-wing systems). Flapping wings also eliminate the necessity of dangerous fast-moving propellers and open the door to actuation mechanisms other than traditional motors. This research explores one of these alternatives: the piezoelectric bending actuator. Piezoelectric materials produce a mechanical strain when an electric charge is applied. With an applied sinusoidal voltage, cantilevered bending piezoelectric actuators create oscillatory motion at the free end that can be translated into wing movement much more directly than a rotational motor. This direct actuation eliminates the need for gears and provides a mechanism for reducing the system\u27s weight. Furthermore, the simplified mechanism can improve robustness by removing contact surfaces that can become clogged or worn (e.g., using gears). While piezoelectric flapping-wing flight has many potential benefits, the combination has only been explored in insect-inspired hovering flight. This work explores the feasibility of larger, forward-flight systems to identify a framework for piezoelectrically-driven flapping-wing vehicles with wing-bending control. Theoretical and experimental analysis methods are presented to study piezoelectric flapping wing motion characteristics for lift and drag effects in flapping-wing aerial systems

A Flight Mechanics-Centric Review of Bird-Scale Flapping Flight

This paper reviews the flight mechanics and control of birds and bird-size aircraft. It is intended to fill a niche in the current survey literature which focuses primarily on the aerodynamics, flight dynamics and control of insect scale flight. We review the flight mechanics from first principles and summarize some recent results on the stability and control of birds and bird-scale aircraft. Birds spend a considerable portion of their flight in the gliding (i.e., non-flapping) phase. Therefore, we also review the stability and control of gliding flight, and particularly those aspects which are derived from the unique control features of birds

Research issues in biological inspired sensors for flying robots

Biological inspired robotics is an area experiencing an increasing research and development. In spite of all the recent engineering advances, robots still lack capabilities with respect to agility, adaptability, intelligent sensing, fault-tolerance, stealth, and utilization of in-situ resources for power when compared to biological organisms. The general premise of bio-inspired engineering is to distill the principles incorporated in successful, nature-tested mechanisms of selected features and functional behaviors that can be captured through biomechatronic designs and minimalist operation principles from nature success strategies. Based on these concepts, robotics researchers are interested in gaining an understanding of the sensory aspects that would be required to mimic nature design with engineering solutions. In this paper are analysed developments in this area and the research aspects that have to be further studied are discussed.N/

A review of linkage mechanisms in animal joints and related bioinspired designs

Abstract: This paper presents a review of biological mechanical linkage mechanisms. One purpose is to identify the range of kinematic functions that they are able to perform. A second purpose is to review progress in bioinspired designs. Ten different linkage mechanisms are presented. They are chosen because they cover a wide range of functionality and because they have potential for bioinspired design. Linkage mechanisms enable animal joints to perform highly sophisticated and optimised motions. A key function of animal linkage mechanisms is the optimisation of actuator location and mechanical advantage. This is crucially important for animals where space is highly constrained. Many of the design features used by engineers in linkage mechanisms are seen in nature, such as short coupler links, extended bars, elastic energy storage and latch mechanisms. However, animal joints contain some features rarely seen in engineering such as integrated cam and linkage mechanisms, nonplanar four-bar mechanisms, resonant hinges and highly redundant actuators. The extreme performance of animal joints together with the unusual design features makes them an important area of investigation for bioinspired designs. Whilst there has been significant progress in bioinspiration, there is the potential for more, especially in robotics where compactness is a key design driver

Science, technology and the future of small autonomous drones

We are witnessing the advent of a new era of robots — drones — that can autonomously fly in natural and man-made environments. These robots, often associated with defence applications, could have a major impact on civilian tasks, including transportation, communication, agriculture, disaster mitigation and environment preservation. Autonomous flight in confined spaces presents great scientific and technical challenges owing to the energetic cost of staying airborne and to the perceptual intelligence required to negotiate complex environments. We identify scientific and technological advances that are expected to translate, within appropriate regulatory frameworks, into pervasive use of autonomous drones for civilian applications