8 research outputs found
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
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
Development, Design, Manufacture and Test of Flapping Wing Micro Aerial Vehicles
The field of FlappingWing Micro Air Vehicles (FWMAV) has been of interest in recent years and as shown to have many aerodynamic principles unconventional to traditional aviation aerodynamics. In addition to traditional manufacturing techniques, MAVs have utilized techniques and machines that have gained significant interest and investment over the past decade, namely in additive manufacturing. This dissertation discusses the techniques used to manufacture and build a 30 gram-force (gf) model which approaches the lower limit allowed by current commercial off-the-shelf items. The vehicle utilizes a novel mechanism that minimizes traditional kinematic issues associated with four bar mechanisms for flapping wing vehicles. A kinematic reasoning for large amplitude flapping is demonstrated namely, by lowering the cycle averaged angular acceleration of the wings. The vehicle is tested for control authority and lift of the mechanism using three servo drives for wing manipulation. The study then discusses the wing design, manufacturing techniques and limitations involved with the wings for a FWMAV. A set of 17 different wings are tested for lift reaching lifts of 38 gf using the aforementioned vehicle design. The variation in wings spurs the investigation of the flow patterns generated by the flexible wings and its interactions for multiple flapping amplitudes. Phase-lock particle image velocimetry (PIV) is used to investigate the unsteady flows generated by the vehicle. A novel flow pattern is experimentally found, namely “trailing edge vortex capture” upon wing reversal for all three flapping amplitudes, alluding to a newly discovered addition to the lift enhancing effect of wake capture. This effect is believed to be a result of flexible wings and may provide lift enhancing characteristics to wake capture
Analysis and optimisation of passive flapping wing propulsion for micro aerial vehicles
Flapping wing propulsion has the potential to revolutionise the field of Micro Aerial Vehicles (MAVs), but little is known about the effect of flapping motion on the performance of flapping wings. Prototype MAVs have achieved flight with passive flapping wings moving in a sinusoidal flapping motion, but the possible benefits of alternative flapping motions have not been studied in detail.
This thesis presents the development of an Integrated Testing System (ITS), which allows the evaluation of flapping wing performance for different flapping motions. A detailed parametric study of the effect of flapping motion on wing performance is performed, and the optimal flapping motion for several passive flapping wings is determined by hardware-in-the-loop optimisation of two wing performance metrics.
The developed ITS was able to automatically test a variety of passive flapping wings, and demonstrated precise control of the flapping motion and accurate and repeatable measurements of average lift force, mechanical power, and wing twist angle. The parametric study revealed that of the three flapping motions tested, the sinusoidal flapping motion generated the highest lift force, but a smoothed triangular motion was able to generate lift significantly more efficiently under load. The optimal flapping motion was successfully determined for three flapping wings, and was found to increase the loaded efficiency of the wings by an average of 31% over a sinusoidal flapping motion. The determined optimal motion was almost identical for the three tested wings, and was found to strongly resemble the flapping motion of insects
These findings demonstrate that significant improvements in the performance of passive flapping wings can be achieved by relatively minor variations of the flapping motion. This increased understanding will ideally lead to more efficient flapping wing MAVs with higher payloads, longer flight times, and improved performance
Proceedings of the International Micro Air Vehicles Conference and Flight Competition 2017 (IMAV 2017)
The IMAV 2017 conference has been held at ISAE-SUPAERO, Toulouse, France from Sept. 18 to Sept. 21, 2017. More than 250 participants coming from 30 different countries worldwide have presented their latest research activities in the field of drones. 38 papers have been presented during the conference including various topics such as Aerodynamics, Aeroacoustics, Propulsion, Autopilots, Sensors, Communication systems, Mission planning techniques, Artificial Intelligence, Human-machine cooperation as applied to drones
Strategies For Enhancing Performance of Flapping Wing Aerial Vehicles Using Multifunctional Structures and Mixed Flight Modes
Biological flapping wing flight offers a variety of advantages over conventional fixed wing aircraft and rotor craft. For example, flapping propulsion can offer the speed of fixed wing aircraft at similar scales while providing the maneuverability of rotor craft. Avian species easily display feats of perching, payload carrying, endurance flying, and transition behavior. In light of these characteristics, emulating and recreating flapping flight in biomimetic or bioinspired work is important in the development of next generation aerial systems. Unfortunately, recreating flapping wing flight is not easily achieved despite numerous efforts to do so. This is in large part due to technological deficiencies. With emerging technologies, it has been possible to begin to unravel the intricacies of flapping flight. Despite technological advancements, offsetting weight with mechanical systems robust enough to provide power and torque while sustaining loading remains difficult. As a result platforms either have simple flapping kinematics with fair payload or have more complex kinematics with limited excess power which in turn limits payload. The former limits capabilities to mirror biological performance characteristics and the latter limits the energy available to power flight which ultimately negatively impacts mission capabilities. Many flapping wing systems are subpar to traditional flying vehicles. Flapping systems can become more competitive in achieving various mission types with increased system performance. In particular, if endurance is coupled with desirable features such as those displayed in nature, i.e., avian perching, they may become superior assets. In this work, four strategies for increasing performance were pursued as follows: (1) increases to maneuverability and payload via a mixed mode approach of flapping wing used in conjunction with propellers, (2) rapid deceleration and variation of flight envelope via inertial control using the battery, (3) increased endurance via integrated energy storage in the wings, and (4) providing endurance to the point of complete energy autonomy using a design framework considering flapping wings with integrated high efficiency solar cells
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Experimental and computational analysis for insect inspired flapping wing micro air vehicles
Many creatures in nature have evolved the ability to fly and some seem to do so effortlessly with captivating movement. The flight characteristics of these natural fliers have greatly fascinated biologists and engineers for a long time that to this day researchers continue to actively work in this field of science with the aim of one day developing a Flapping Wing Micro Aerial Vehicle (FWMAV) which can replicate the flight of nature's creatures. These types of autonomous robotic vehicles can fulfil tasks which are not suitable for manned vehicles especially when risks to human safety are present. Flight techniques such as control, stability and manoeuvrability are flight characteristics which an FWMAV must possess if such a device is employed for various rescue missions. With this in mind symmetrical and asymmetrical wing motions are studied experimentally in the current research programme in such a way that the methodology employed for this type of flight can be implemented into future FWMAVs.
In summary, the research performed during the course of this project produced innovative results in the form of the creation of two micro air vehicles with a thorough explanation of the development process and examination under experimental tests. Various parameters were analysed during the experimental tests such as force, moment, power and wing position measurements. The tests were performed on both models, one of which has the functionality to perform asymmetrical flapping and successfully generate moments about two different axes. A unique wing motion which favoured the upward vertical force production was investigated under various scenarios. The wings keep a fixed angle of attack during the downwards flapping motion and are allowed to passively rotate during the upstroke motion. Computational simulations were performed to investigate the hovering fluid dynamics, forces, moments and power required for various chordwise rotational positions and durations of wing rotation. This investigation aided in understanding the full effects of altering these parameters under hovering conditions for a rectangular wing. The valuable results found from this research program provide a better insight into various topics involving micro air vehicles in addition to developing future flight worthy insect inspired vehicles
Advances in Bio-Inspired Robots
This book covers three major topics, specifically Biomimetic Robot Design, Mechanical System Design from Bio-Inspiration, and Bio-Inspired Analysis on A Mechanical System. The Biomimetic Robot Design part introduces research on flexible jumping robots, snake robots, and small flying robots, while the Mechanical System Design from Bio-Inspiration part introduces Bioinspired Divide-and-Conquer Design Methodology, Modular Cable-Driven Human-Like Robotic Arm andWall-Climbing Robot. Finally, in the Bio-Inspired Analysis on A Mechanical System part, research contents on the control strategy of Surgical Assistant Robot, modeling of Underwater Thruster, and optimization of Humanoid Robot are introduced