Academic literature on the topic 'Fixed Wing MAVs'
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Journal articles on the topic "Fixed Wing MAVs"
1
Watkins, A., M. Thompson, M. Shortis, R. Segal, M. Abdulrahim, and J. Sheridan. "An overview of experiments on the dynamic sensitivity of MAVs to turbulence." Aeronautical Journal 114, no. 1158 (August 2010): 485–92. http://dx.doi.org/10.1017/s0001924000003973.
Full textAbstract:
Abstract Aspects of the turbulent wind environment Micro Air Vehicles (MAVs) experience when flying outdoors were replicated in a large wind tunnel. An overview of the facility, instrumentation and initial flight tests is given. Piloting inputs and aircraft accelerations were recorded on fixed and rotary wing MAVs and for some tests, measurements of the approach flow (u,v,w sampled at 1,250Hz at four laterally disposed upstream locations) were made. The piloting aim was to hold straight and level flight in the 12m wide × 4m high × ~50m long test section, while flying in a range of turbulent conditions. The Cooper-Harper rating system showed that a rotary craft was less sensitive to the effects of turbulence compared to the fixed wing craft and that while the fixed wing aircraft was relatively easy to fly in smooth air, it became extremely difficult to fly under high turbulence conditions. The rotary craft, while more difficult to fly per. se., did not become significantly harder to fly in relatively high turbulence levels. However the rotary craft had a higher mass and MOI than the fixed wing craft and further work is planned to understand the effects of these differences.
2
Lin, Jih‐Lung, Chin‐Yi Wei, and Chi‐Yu Lin. "Design and testing of fixed‐wing MAVs." Aircraft Engineering and Aerospace Technology 79, no. 4 (July 10, 2007): 346–51. http://dx.doi.org/10.1108/00022660710758213.
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Aboelezz, Ahmed, Yunes Elqudsi, Mostafa Hassanalian, and Ahmed Desoki. "WIND TUNNEL CALIBRATION, CORRECTIONS AND EXPERIMENTAL VALIDATION FOR FIXED-WING MICRO AIR VEHICLES MEASUREMENTS." Aviation 23, no. 4 (February 17, 2020): 104–13. http://dx.doi.org/10.3846/aviation.2019.11975.
Full textAbstract:
The increase in the number of Unmanned Aerial Vehicles (UAVs) and Micro Air Vehicles (MAVs), which are used in a variety of applications has led to a surge in low Reynolds number aerodynamics research. Flow around fixedwing MAVs has an unusual behavior due to its low aspect ratio and operates at low Reynolds number, which demanded to upgrade the used wind tunnel for this study. This upgrade enables measuring the small aerodynamics forces and moment of fixed-wing MAVs. The wind tunnel used in this work is upgraded with a state of art data acquisition system to deal with the different sensors signals in the wind tunnel. For accurate measurements, the sting balance, angle sensor, and airspeed sensor are calibrated. For validation purposes, an experiment is made on a low aspect ratio flat plate wing at low Reynolds number, and the measured data are corrected and compared with published results. The procedure presented in this paper for the first time gave a detailed and complete guide for upgrading and calibrating old wind tunnel, all the required corrections to correct the measured data was presented, the turbulence level correction new technique presented in this paper could be used to estimate the flow turbulence effect on the measured data and correct the measured data against published data.
4
Trittler, M., T. Rothermel, and W. Fichter. "Visual Servoing Based Landing Approach Controller for Fixed-Wing MAVs." IFAC Proceedings Volumes 46, no. 19 (2013): 200–205. http://dx.doi.org/10.3182/20130902-5-de-2040.00024.
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5
Trittler, M., W. Fichter, and A. Schöttl. "Return Strategies for Fixed-Wing MAVs After Loss of GPS." IFAC Proceedings Volumes 46, no. 19 (2013): 254–59. http://dx.doi.org/10.3182/20130902-5-de-2040.00083.
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6
Mohamed, Abdulghani, Kevin Massey, Simon Watkins, and Reece Clothier. "The attitude control of fixed-wing MAVS in turbulent environments." Progress in Aerospace Sciences 66 (April 2014): 37–48. http://dx.doi.org/10.1016/j.paerosci.2013.12.003.
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7
Hota, Sikha, and Debasish Ghose. "Waypoint-Based Trajectory Planning of Fixed-Wing MAVs in 3D Space." Journal of Intelligent & Robotic Systems 86, no. 1 (October 1, 2016): 95–113. http://dx.doi.org/10.1007/s10846-016-0415-3.
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8
Goszczyński, Jacek A., Maciej Lasek, Józef Pietrucha, and Krzysztof Sibilski. "ANIMALOPTERS-TOWARDS A NEW DIMENSION OF FLIGHT MECHANICS." TRANSPORT 17, no. 3 (June 30, 2002): 108–16. http://dx.doi.org/10.3846/16483840.2002.10414023.
Full textAbstract:
Recently, it has been recognised that flapping wing propulsion can be more efficient than conventional propellers if applied to very small-scale vehicles, so-called MAVs (micro air vehicles). Extraordinary possibilities of such objects, particularly in the context of special missions, are discussed. Flapping flight is more complicated than flight with fixed or rotating wings. Therefore, there is a need to understand the mechanisms of force generation by flapping wings in a more comprehensive way. The paper describes the current work on flapping wing conducted by the Flying amp;Swimming Puzzle Group. The key to understand the mechanisms of flapping flight is the adequate physical and mathematical modelling; modelling problems of flow and motion are emphasised. Sample calculations illustrating current capabilities of the method have been performed. The effect of feathering amplitude, flapping amplitude, and phase shifting on the MAV&s control effectiveness has been examined. It has been discovered that the parameters mentioned above can be considered as control parameters of “flapping wing” MAVs, especially in lateral direction. Research programmes for the construction of MAYs concentrate on understanding the mechanisms of animal flight and on creating smart structures which would enable flight in micro-scale.
9
Cosyn, P., and J. Vierendeels. "Design of fixed wing micro air vehicles." Aeronautical Journal 111, no. 1119 (May 2007): 315–26. http://dx.doi.org/10.1017/s0001924000004565.
Full textAbstract:
Abstract The paper describes the methodology and computational design strategies used to develop a series of fixed wing micro air vehicles (MAVs) at the Ghent University. The emphasis of the research is to find an optimal MAV-platform that is bound to geometrical constraints but superior in its performance. This requires a multidisciplinary design optimisation but the challenges are mainly of aerodynamic nature. Key areas are endurance, stability, controllability, manoeuvrability and component integration. The highly three-dimensional low Reynolds number flow, the lack of experimental databases and analytical or empirical models of MAV-aerodynamics required fundamental research of the phenomena. This includes the use of a vortex lattice method, three-dimensional CFD-computations and a numerical propeller optimisation method to derive the forces and their derivatives of the MAV and propeller for performance and stability-related optimisation studies. The design method leads to a simple, stable and robust flying wing MAV-platform that has the agility of a fighter airplane. A prototype, the UGMAV25, was constructed and flight tests were performed. The capabilities of the MAV were tested in a series of successful flight manoeuvres. The UGMAV15, a MAV with a span of 15cm, is also developed to test flight-qualities and endurance at this small scale. With the current battery technology, a flight-time of at least one hour is expected.
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Sibilski, Krzysztof, Mirosław Nowakowski, Dariusz Rykaczewski, Paweł Szczepaniak, Andrzej Żyluk, Anna Sibilska-Mroziewicz, Michał Garbowski, and Wiesław Wróblewski. "Identification of Fixed-Wing Micro Aerial Vehicle Aerodynamic Derivatives from Dynamic Water Tunnel Tests." Aerospace 7, no. 8 (August 13, 2020): 116. http://dx.doi.org/10.3390/aerospace7080116.
Full textAbstract:
A micro air vehicle (MAV) is a class of miniature unmanned aerial vehicles that has a size restriction and may be autonomous. Fixed-wing MAVs are very attractive for outdoor surveillance missions since they generally offer better payload and endurance capabilities than rotorcraft or flapping-wing vehicles of equal size. This research paper describes the methodology applying indicial function theory and artificial neural networks for identification of aerodynamic derivatives for fixed-wing MAV. The formulation herein proposed extends well- known aerodynamic theories, which are limited to thin aerofoils in incompressible flow, to strake wing planforms. Using results from dynamic water tunnel tests and indicial functions approach allowed to identify MAV aerodynamic derivatives. The experiments were conducted in a water tunnel in the course of dynamic tests of periodic oscillatory motion. The tests program range was set at high angles of attack and a wide scope of reduced frequencies of angular movements. Due to a built-in propeller, the model’s structure test program was repeated for a turned-on propelled drive system. As a result of these studies, unsteady aerodynamics characteristics and aerodynamic derivatives of the micro-aircraft were identified as functions of state parameters. At the Warsaw University of Technology and the Air Force Institute of Technology, a “Bee” fixed wings micro aerial vehicle with an innovative strake-wing outline and a propeller placed in the wing gap was worked. This article is devoted to the problems of identification of aerodynamic derivatives of this micro-aircraft. The result of this research was the identification of the aerodynamic derivatives of the fixed wing MAV “Bee” as non-linear functions of the angle of attack, and reduced frequency. The identification was carried out using the indicial function approach.
Dissertations / Theses on the topic "Fixed Wing MAVs"
1
Bera, Titas. "Application of Randomized Algorithms in Path Planning and Control of a Micro Air Vehicle." Thesis, 2015. http://etd.iisc.ac.in/handle/2005/3756.
Full textAbstract:
This thesis focuses on the design and development of a fixed wing micro air vehicle (MAV) and on the development of randomized sampling based motion planning and control algorithms for path planning and stabilization of the MAV. In addition, the thesis also contains probabilis-tic analyses of the algorithmic properties of randomized sampling based algorithms, such as completeness and asymptotic optimality.
The thesis begins with a detailed discussion on aerodynamic design, computational fluid dy-namic simulations of propeller wake, wind tunnel tests of a 150mm fixed wing micro air ve-hicle. The vehicle is designed in such a way that in spite of the various adverse effects of low Reynolds number aerodynamics and the complex propeller wake interactions with the airframe, the vehicle shows a balance of external forces and moments at most of the operating conditions. This is supported by various CFD analysis and wind tunnel tests and is shown in this thesis. The thesis also contains a reasonably accurate longitudinal and lateral dynamical model of the MAV, which are verified by numerous flight trials.
However, there still exists a considerable amount of model uncertainties in the system descrip-tion of the MAV. A robust feedback stabilized close loop flight control law, is designed to attenuate the effects of modelling uncertainties, discrete vertical and head-on wind gusts, and to maintain flight stability and performance requirements at all allowable operating conditions. The controller is implemented in the MAV autopilot hardware with successful close loop flight trials. The flight controller is designed based on the probabilistic robust control approach. The approach is based on statistical average case analysis and synthesis techniques. It removes the conservatism present in the classical robust feedback design (which is based the worst case de-sign techniques) and associated sluggish system response characteristics. Instead of minimizing the effect of the worst case disturbance, a randomized techniques synthesizes a controller for which some performance index is minimized in an empirical average sense. In this thesis it is shown that the degree of conservatism in the design and the number of samples used to by the randomized sampling based techniques has a direct relationship. In particular, it is shown that, as the lower bound on the number of samples reduces, the degree of conservatism increases in the design.
Classical motion planning and obstacle avoidance methodologies are computationally expen-sive with the number of degrees of freedom of the vehicle, and therefore, these methodologies are largely inapplicable for MAVs with 6 degrees of freedom. The problem of computational complexity can be avoided using randomized sampling based motion planning algorithms such as probabilistic roadmap method or PRM. However, as a pay-off these algorithms lack algorith-mic completeness properties. In this thesis, it is established that the algorithmic completeness properties are dependent on the choice of the sampling sequences. The thesis contains analy-sis of algorithmic features such as probabilistic completeness and asymptotic optimality of the PRM algorithm and its many variants, under the incremental and independent problem model framework. It is shown in this thesis that the structure of the random sample sequence affects the solution of the sampling based algorithms.
The problem of capturing the connectivity of the configuration space in the presence of ob-stacles, which is a central problem in randomized motion planning, is also discussed in this thesis. In particular, the success probability of one such randomized algorithm, named Obsta-cle based Probabilistic Roadmap Method or OBPRM is estimated using geometric probability theory. A direct relationship between the weak upper bound of the success probability and the obstacle geometric features is established. The thesis also contains a new sampling based algorithm which is based on geometric random walk theory, which addresses the problem of capturing the connectivity of the configuration space. The algorithm shows better performance when compared with other similar algorithm such as the Randomized Bridge Builder method for identical benchmark problems. Numerical simulation shows that the algorithm shows en-hanced performance as the dimension of the motion planning problem increases.
As one of the central objectives, the thesis proposes a pre-processing technique of the state space of the system to enhance the performance of sampling based kino-dynamic motion plan-ner such as rapidly exploring random tree or RRT. This pre-processing technique can not only be applied for the motion planning of the MAV, but can also be applied for a wide class of vehicle and complex systems with large number of degrees of freedom. The pre-processing techniques identifies the sequence of regions, to be searched for a solution, in order to do mo-tion planning and obstacle avoidance for an MAV, by an RRT planner. Numerical simulation shows significant improvement over the basic RRT planner with a small additional computa-tional overhead. The probabilistic analysis of RRT algorithm and an approximate asymptotic optimality analysis of the solution returned by the algorithm, is also presented in this thesis. In particular, it is shown that the RRT algorithm is not asymptotically optimal.
An integral part of the motion planning algorithm is the capability of fast collision detection between various geometric objects. Image space based methods, which uses Graphics Pro-cessing Unit or GPU hardware, and do not use object geometry explicitly, are found to be fast and accurate for this purpose. In this thesis, a new collision detection method between two convex/non-convex objects using GPU, is provided. The performance of the algorithm, which is an extension of an existing algorithm, is verified with numerous collision detection scenarios.
2
Bera, Titas. "Application of Randomized Algorithms in Path Planning and Control of a Micro Air Vehicle." Thesis, 2015. http://etd.iisc.ernet.in/2005/3756.
Full textAbstract:
This thesis focuses on the design and development of a fixed wing micro air vehicle (MAV) and on the development of randomized sampling based motion planning and control algorithms for path planning and stabilization of the MAV. In addition, the thesis also contains probabilis-tic analyses of the algorithmic properties of randomized sampling based algorithms, such as completeness and asymptotic optimality.
The thesis begins with a detailed discussion on aerodynamic design, computational fluid dy-namic simulations of propeller wake, wind tunnel tests of a 150mm fixed wing micro air ve-hicle. The vehicle is designed in such a way that in spite of the various adverse effects of low Reynolds number aerodynamics and the complex propeller wake interactions with the airframe, the vehicle shows a balance of external forces and moments at most of the operating conditions. This is supported by various CFD analysis and wind tunnel tests and is shown in this thesis. The thesis also contains a reasonably accurate longitudinal and lateral dynamical model of the MAV, which are verified by numerous flight trials.
However, there still exists a considerable amount of model uncertainties in the system descrip-tion of the MAV. A robust feedback stabilized close loop flight control law, is designed to attenuate the effects of modelling uncertainties, discrete vertical and head-on wind gusts, and to maintain flight stability and performance requirements at all allowable operating conditions. The controller is implemented in the MAV autopilot hardware with successful close loop flight trials. The flight controller is designed based on the probabilistic robust control approach. The approach is based on statistical average case analysis and synthesis techniques. It removes the conservatism present in the classical robust feedback design (which is based the worst case de-sign techniques) and associated sluggish system response characteristics. Instead of minimizing the effect of the worst case disturbance, a randomized techniques synthesizes a controller for which some performance index is minimized in an empirical average sense. In this thesis it is shown that the degree of conservatism in the design and the number of samples used to by the randomized sampling based techniques has a direct relationship. In particular, it is shown that, as the lower bound on the number of samples reduces, the degree of conservatism increases in the design.
Classical motion planning and obstacle avoidance methodologies are computationally expen-sive with the number of degrees of freedom of the vehicle, and therefore, these methodologies are largely inapplicable for MAVs with 6 degrees of freedom. The problem of computational complexity can be avoided using randomized sampling based motion planning algorithms such as probabilistic roadmap method or PRM. However, as a pay-off these algorithms lack algorith-mic completeness properties. In this thesis, it is established that the algorithmic completeness properties are dependent on the choice of the sampling sequences. The thesis contains analy-sis of algorithmic features such as probabilistic completeness and asymptotic optimality of the PRM algorithm and its many variants, under the incremental and independent problem model framework. It is shown in this thesis that the structure of the random sample sequence affects the solution of the sampling based algorithms.
The problem of capturing the connectivity of the configuration space in the presence of ob-stacles, which is a central problem in randomized motion planning, is also discussed in this thesis. In particular, the success probability of one such randomized algorithm, named Obsta-cle based Probabilistic Roadmap Method or OBPRM is estimated using geometric probability theory. A direct relationship between the weak upper bound of the success probability and the obstacle geometric features is established. The thesis also contains a new sampling based algorithm which is based on geometric random walk theory, which addresses the problem of capturing the connectivity of the configuration space. The algorithm shows better performance when compared with other similar algorithm such as the Randomized Bridge Builder method for identical benchmark problems. Numerical simulation shows that the algorithm shows en-hanced performance as the dimension of the motion planning problem increases.
As one of the central objectives, the thesis proposes a pre-processing technique of the state space of the system to enhance the performance of sampling based kino-dynamic motion plan-ner such as rapidly exploring random tree or RRT. This pre-processing technique can not only be applied for the motion planning of the MAV, but can also be applied for a wide class of vehicle and complex systems with large number of degrees of freedom. The pre-processing techniques identifies the sequence of regions, to be searched for a solution, in order to do mo-tion planning and obstacle avoidance for an MAV, by an RRT planner. Numerical simulation shows significant improvement over the basic RRT planner with a small additional computa-tional overhead. The probabilistic analysis of RRT algorithm and an approximate asymptotic optimality analysis of the solution returned by the algorithm, is also presented in this thesis. In particular, it is shown that the RRT algorithm is not asymptotically optimal.
An integral part of the motion planning algorithm is the capability of fast collision detection between various geometric objects. Image space based methods, which uses Graphics Pro-cessing Unit or GPU hardware, and do not use object geometry explicitly, are found to be fast and accurate for this purpose. In this thesis, a new collision detection method between two convex/non-convex objects using GPU, is provided. The performance of the algorithm, which is an extension of an existing algorithm, is verified with numerous collision detection scenarios.
3
Satak, Neha. "Design, Development And Flight Control Of Sapthami - A Fixed Wing Micro Air Vehicle." Thesis, 2008. https://etd.iisc.ac.in/handle/2005/872.
Full textAbstract:
Two micro air vehicles, namely Sapthami and Sapthami-flyer, are developed in this thesis. Their total weight is less than 200grams each. They fit inside a 30cm and 32cm sphere respectively and carry the commercially available Kestrel autopilot hardware. The vehicles have an endurance of around 20-30 minutes. The stall speed of Sapthami is around 7m/s and that of Sapthami-flyer is around 5m/s as found by nonlinear modeling. The low stall speed makes it possible for them to be launched by hand. This enhances their portability as they do not require any launching equipment. The vehicle installed with Kestrel autopilot system is capable of many modes of operations. It is capable of fully autonomous flight with the aid of a variety of sensors like the GPS unit, heading sensor, 2-axis magnetometer, 3-axis accelerometer and 3-axis gyros. The vehicle carrying the Kestrel autopilot hardware is capable of autonomous and semi-autonomous flights after installation and tuning of feedback loops.
Sapthami, is a tailless flying wing with an inverse zimmermann profile. A flying wing is a preferred configuration for the MAV as it maximizes the lifting area for a given size constraint. For a maximum size constraint of 30cm and aspect ratio around 1, the vehicle operates at Reynolds number between 100,000 to 250,000, at flight velocity 7 m/s to 15 m/s. The Inverse Zimmerman profile has a higher lift coefficient, CL, in comparison to the other planforms such as rectangular, elliptical and Zimmermann, for aspect ratio 1 to 1.25 and tested at Reynolds number of 100,000. The configuration of Sapthami is clean as there is no fuselage and all the components like autopilot hardware and battery are housed inside the wing. A thick reflex Martin Hepperle (MH) airfoil MH18 is chosen which gives sufficient space to place the components. This airfoil is specially used for tailless configurations due to its negative camber at the trailing edge. This negative camber helps in reducing the negative pitching moment of the wing, since no separate horizontal tail is available on a tailless aircraft to compensate for it. The vehicle is fabricated using the blue foam, having a density of 30kg/m3 . The wing is fabricated by CNC machining after which slots are cut manually to embed the electronics. The vehicle is found to have stable flying characteristics. Limited flight trials are done for Sapthami. It takes large time to fabricate the vehicle due to limited availability of CNC machining facility. Therefore, a new tailless, wing-fuselage configuration, which can be fabricated with balsa wood, is designed.
Sapthami-flyer is the second vehicle designed in this thesis. Its wing span is slightly more than Sapthami. Since it is a wing-fuselage configuration, therefore there is no need for a thick airfoil. Mark drela’s AG airfoils are found to have better lift than MH airfoils for the inverse Zimmerman profile. The thickness of the airfoils is reduced to 1% so that the wing can be made by a 1.5mm thick balsa sheet to reduce weight. The inverse Zimmermann profile wing with the AG09 airfoil is found to have best lift-to-drag ratio when compared to AG36, MH45 and MH18. The analysis is done using commercially available AVL software. AG09 with 1% thickness is used in the final configuration. This configuration has better short period damping than Sapthami. It also has slower modes of operation than Sapthami.
The operating modes of most of the MAVs, including Sapthami and Sapthami-flyer, are lowly damped but fast. This makes it difficult for the pilot to fly the vehicle. To improve the flying qualities of the vehicle artificial stabilization is required. The feedback is implemented on the Kestrel autopilot hardware. It allows only PID based feedback structures to be implemented, hence gives no choice to the designer to implement higher order control. The digital integrator and differentiator implementation for feedback are non-ideal. This further reduces the effectiveness of control. The problem is dealt with by incorporating the additional dynamics introduced by these implementation while formulating the control problem. Further the modeling of the micro air vehicle is done by using vortex lattice simulation based softwares. The fidelity of the obtained dynamics is low. Therefore, there is high uncertainty in the plant model. The controller also needs to reject the wind gust disturbances which are of the order of the flight speed of the vehicle. All the above stated requirements from the control design can be best addressed by a robust control design.
Sapthami-flyer uses aileron and elevator for control. There is no rudder in the configuration in order to reduce weight. In the longitudinal dynamics, pitch rate and pitch error feedback to elevator are used to increase the short period and phugoid damping respectively. In the lateral dynamics, a combination of roll rate, yaw rate and roll error feedback is given to aileron to improve the dutch roll damping and stabilize the spiral mode. The feedback loops for both longitudinal and lateral dynamics are multi-output single input design problems, therefore simultaneous tuning of loops is beneficial.
The PID control is designed by first converting the actual plant to a static output feedback equivalent plant. The dynamics introduced by non-ideal differentiator and integrator implementation on the autopilot hardware are incorporated in the open loop static output feedback formulation. The robust pole placement for the SOF plant is done by using the modified iterative matrix inequality algorithm developed in this thesis. It is capable of multi-loop, multi-objective feedback design for SOF plants. The algorithm finds the optimal solution by simultaneously putting constraints on the H2 performance, pole placement, gain and phase margin of the closed loop system. The pole placement is done to minimize the real part of largest eigenvalue. A single controller is designed at a suit-able operating point and constraints are put on the gain and phase margin of the closed loop plant at other operating points. The designed controller is tested in flight on board Sapthami-flyer. The vehicle is also capable of tracking commanded pitch and roll attitude with the help of pitch error, roller or feedbacks. This is shown in the flight when the pilot leaves the RC stick and the vehicle tracks the desired attitude. The vehicle has shown improved flying characteristics in the closed loop mode.
4
Satak, Neha. "Design, Development And Flight Control Of Sapthami - A Fixed Wing Micro Air Vehicle." Thesis, 2008. http://hdl.handle.net/2005/872.
Full textAbstract:
Two micro air vehicles, namely Sapthami and Sapthami-flyer, are developed in this thesis. Their total weight is less than 200grams each. They fit inside a 30cm and 32cm sphere respectively and carry the commercially available Kestrel autopilot hardware. The vehicles have an endurance of around 20-30 minutes. The stall speed of Sapthami is around 7m/s and that of Sapthami-flyer is around 5m/s as found by nonlinear modeling. The low stall speed makes it possible for them to be launched by hand. This enhances their portability as they do not require any launching equipment. The vehicle installed with Kestrel autopilot system is capable of many modes of operations. It is capable of fully autonomous flight with the aid of a variety of sensors like the GPS unit, heading sensor, 2-axis magnetometer, 3-axis accelerometer and 3-axis gyros. The vehicle carrying the Kestrel autopilot hardware is capable of autonomous and semi-autonomous flights after installation and tuning of feedback loops.
Sapthami, is a tailless flying wing with an inverse zimmermann profile. A flying wing is a preferred configuration for the MAV as it maximizes the lifting area for a given size constraint. For a maximum size constraint of 30cm and aspect ratio around 1, the vehicle operates at Reynolds number between 100,000 to 250,000, at flight velocity 7 m/s to 15 m/s. The Inverse Zimmerman profile has a higher lift coefficient, CL, in comparison to the other planforms such as rectangular, elliptical and Zimmermann, for aspect ratio 1 to 1.25 and tested at Reynolds number of 100,000. The configuration of Sapthami is clean as there is no fuselage and all the components like autopilot hardware and battery are housed inside the wing. A thick reflex Martin Hepperle (MH) airfoil MH18 is chosen which gives sufficient space to place the components. This airfoil is specially used for tailless configurations due to its negative camber at the trailing edge. This negative camber helps in reducing the negative pitching moment of the wing, since no separate horizontal tail is available on a tailless aircraft to compensate for it. The vehicle is fabricated using the blue foam, having a density of 30kg/m3 . The wing is fabricated by CNC machining after which slots are cut manually to embed the electronics. The vehicle is found to have stable flying characteristics. Limited flight trials are done for Sapthami. It takes large time to fabricate the vehicle due to limited availability of CNC machining facility. Therefore, a new tailless, wing-fuselage configuration, which can be fabricated with balsa wood, is designed.
Sapthami-flyer is the second vehicle designed in this thesis. Its wing span is slightly more than Sapthami. Since it is a wing-fuselage configuration, therefore there is no need for a thick airfoil. Mark drela’s AG airfoils are found to have better lift than MH airfoils for the inverse Zimmerman profile. The thickness of the airfoils is reduced to 1% so that the wing can be made by a 1.5mm thick balsa sheet to reduce weight. The inverse Zimmermann profile wing with the AG09 airfoil is found to have best lift-to-drag ratio when compared to AG36, MH45 and MH18. The analysis is done using commercially available AVL software. AG09 with 1% thickness is used in the final configuration. This configuration has better short period damping than Sapthami. It also has slower modes of operation than Sapthami.
The operating modes of most of the MAVs, including Sapthami and Sapthami-flyer, are lowly damped but fast. This makes it difficult for the pilot to fly the vehicle. To improve the flying qualities of the vehicle artificial stabilization is required. The feedback is implemented on the Kestrel autopilot hardware. It allows only PID based feedback structures to be implemented, hence gives no choice to the designer to implement higher order control. The digital integrator and differentiator implementation for feedback are non-ideal. This further reduces the effectiveness of control. The problem is dealt with by incorporating the additional dynamics introduced by these implementation while formulating the control problem. Further the modeling of the micro air vehicle is done by using vortex lattice simulation based softwares. The fidelity of the obtained dynamics is low. Therefore, there is high uncertainty in the plant model. The controller also needs to reject the wind gust disturbances which are of the order of the flight speed of the vehicle. All the above stated requirements from the control design can be best addressed by a robust control design.
Sapthami-flyer uses aileron and elevator for control. There is no rudder in the configuration in order to reduce weight. In the longitudinal dynamics, pitch rate and pitch error feedback to elevator are used to increase the short period and phugoid damping respectively. In the lateral dynamics, a combination of roll rate, yaw rate and roll error feedback is given to aileron to improve the dutch roll damping and stabilize the spiral mode. The feedback loops for both longitudinal and lateral dynamics are multi-output single input design problems, therefore simultaneous tuning of loops is beneficial.
The PID control is designed by first converting the actual plant to a static output feedback equivalent plant. The dynamics introduced by non-ideal differentiator and integrator implementation on the autopilot hardware are incorporated in the open loop static output feedback formulation. The robust pole placement for the SOF plant is done by using the modified iterative matrix inequality algorithm developed in this thesis. It is capable of multi-loop, multi-objective feedback design for SOF plants. The algorithm finds the optimal solution by simultaneously putting constraints on the H2 performance, pole placement, gain and phase margin of the closed loop system. The pole placement is done to minimize the real part of largest eigenvalue. A single controller is designed at a suit-able operating point and constraints are put on the gain and phase margin of the closed loop plant at other operating points. The designed controller is tested in flight on board Sapthami-flyer. The vehicle is also capable of tracking commanded pitch and roll attitude with the help of pitch error, roller or feedbacks. This is shown in the flight when the pilot leaves the RC stick and the vehicle tracks the desired attitude. The vehicle has shown improved flying characteristics in the closed loop mode.
Books on the topic "Fixed Wing MAVs"
1
L, Wilbur Matthew, Langley Research Center, and U.S. Army Research Laboratory., eds. Wind-tunnel evaluation of the effect of blade nonstructural mass distribution on helicopter fixed-system loads. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1998.
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2
L, Wilbur Matthew, U.S. Army Research Laboratory., and Langley Research Center, eds. Wind-tunnel evaluation of the effect of blade nonstructural mass distribution on helicopter fixed-system loads. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1998.
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3
United States. National Aeronautics and Space Administration., ed. WIND-TUNNEL EVALUATION OF THE EFFECT OF BLADE NONSTRUCTURAL MASS DISTRIBUTION ON HELICOPTER FIXED-SYSTEM LOADS... NASA/TM-1998-206281... APR. [S.l: s.n., 1999.
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4
United States. National Aeronautics and Space Administration., ed. WIND-TUNNEL EVALUATION OF THE EFFECT OF BLADE NONSTRUCTURAL MASS DISTRIBUTION ON HELICOPTER FIXED-SYSTEM LOADS... NASA/TM-1998-206281... APR. [S.l: s.n., 1999.
Find full textBook chapters on the topic "Fixed Wing MAVs"
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Huang, Wanrong, Yanzhen Wang, Hai Yang, Xiaodong Yi, and Xuejun Yang. "Distributed Control for Formation Switch of Fixed Wing MAVs." In Proceedings of 2016 Chinese Intelligent Systems Conference, 255–66. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-2338-5_25.
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Gros, Michael, Moritz Niendorf, Alfred Schöttl, and Walter Fichter. "Motion Planning for a Fixed-Wing MAV Incorporating Closed-Loop Dynamics Motion Primitives and Safety Maneuvers." In Advances in Aerospace Guidance, Navigation and Control, 247–60. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-19817-5_20.
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"Optic Flow Sensors for MAV Navigation." In Fixed and Flapping Wing Aerodynamics for Micro Air Vehicle Applications, 557–74. Reston ,VA: American Institute of Aeronautics and Astronautics, 2001. http://dx.doi.org/10.2514/5.9781600866654.0557.0574.
Full textConference papers on the topic "Fixed Wing MAVs"
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Green, William E., and Paul Y. Oh. "Towards Autonomous Fixed-Wing MAVs With Hovering Capabilities." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-79735.
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Near-Earth environments, such as forests, caves, tunnels, and urban structures make reconnaissance, surveillance and search-and-rescue missions dificult and dangerous to accomplish. Micro-Air-Vehicles (MAVs), equipped with wireless cameras, can assist in such missions by providing real-time situational awareness. This paper describes an additional flight modality enabling fixed-wing MAVs to supplement existing endurance superiority with hovering capabilities. This secondary flight mode can also be used to avoid imminent collisions by quickly transitioning from cruise to hover ight. A sensor suite which will allow for autonomous hovering by regulating the aircraft’s yaw, pitch and roll angles is also described.
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Singh, Nikhil K., and Sikha Hota. "Waypoint Following for Fixed-Wing MAVs in 3D Space." In 2018 AIAA Guidance, Navigation, and Control Conference. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2018. http://dx.doi.org/10.2514/6.2018-1592.
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Sharma, Rajnikant, Jeffery Saunders, Clark Taylor, and Randal Beard. "Reactive Collision Avoidance for Fixed-Wing MAVs Flying in Urban Terrain." In AIAA Guidance, Navigation, and Control Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2009. http://dx.doi.org/10.2514/6.2009-6180.
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Rajeevalochanam, Prathapanayaka, Vinod Kumar Nanjundaiah, Santhosh Kumar Sahadevan, Narendra Sharma, and Krishnamurthy Settisara Janney. "Comparative Study of Two and Three Blade Mini Propellers Aerodynamic Performance." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-56174.
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Fixed wing Micro Air Vehicles (MAVs) are widely powered by miniature brushless DC motors and mini propellers. These motors have low efficiencies in the MAVs’ operating range; hence consume more power and penalizing the endurance of MAVs flight. Mini propellers also suffer with lower efficiencies due to low Reynolds number effect compared to bigger propellers. Based on the power requirement of MAV’s; generally two bladed different size propellers are used to power these MAVs. Effect of Propeller slipstream wash on the lift generating wings is significant and it is well reported for bigger propellers. The strength of slipstream wash depends on the number of blades, diameter of the propeller, rotational speed, flight speed and trajectory. The effect of slipstream wash could be lowered by increasing the number of blades and with smaller diameter propellers. CSIR-NAL has designed, developed, and fabricated, efficient, 6inch diameter, two and three blade, light-weight, mini propellers using latest state of the art technological advancements for CSIR-NAL fixed wing MAV code named as Black Kite. Apart from this, these propellers are assessed for its realistic propulsive efficiencies using CSIR-NAL configured sophisticated precision test bench manufactured and supplied by M/s MAGTROL, Switzerland. The specialty of this test bench is that it can measure thrust, propellers shaft torque, input power and rotational speeds simultaneously. In the present study CSIR-NAL developed 6 inch diameter two and three bladed propellers of identical plan form are compared for their performance. The three bladed propellers generate 30% higher thrust by marginal weight and efficiency penalty, whereas the noise levels are reduced.
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Noughabi, Amir Karimi, and Mehran Tadjfar. "Cross-Wind Influence on Low Aspect Ratio Wings at Low Reynolds Numbers." In ASME 2013 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fedsm2013-16523.
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The aerodynamics of the low aspect ratio (LAR) wings is of outmost importance in the performance of the fixed-wing micro air vehicles (MAVs). The flow around these wings is widely influenced by three dimensional (3D) phenomena: including wing-tip vortices, formation of laminar bubble, flow separation and reattachment, laminar to turbulent transition or any combination of these phenomena. All the recent studies consider the aerodynamic characteristics of the LAR wings under the effect of the direct wind. Here we focus on the numerical study of the influence of cross-wind on flow over the inverse Zimmerman wings with the aspect ratios (AR) between 1 and 2 at Reynolds numbers between 6×104 and 105. We have considered cross-wind’s angles from 0° to 40° and angle of attack from 0° to 12°. The results show that lift and drag coefficient generally decrease when the angle of the cross-wind is increased.
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Borah, Bastav, Vinayak Kulkarni, and Ujjwal K. Saha. "Aerodynamic Analysis of Flat Plates as Lift Generating Devices for Micro Aerial Vehicles." In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-69419.
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Abstract With the advent of Micro Aerial Vehicles (MAVs) and their widespread applications, the use of flat plate as a lift generation device has drawn utmost attention, and therefore, it needs to be investigated further. Usually, fixed wing MAVs work in the range of Reynolds number, Re = 104–105, and it is reported that a flat plate shows a better lift-to-drag ratio in this range of Re as compared to conventional airfoils. This investigation aims to understand the aerodynamic characteristics of a flat plate at low Re and its applicability on fixed wing MAVs. In this regard, a two-dimensional computational study using the Spalart-Allmaras turbulence model is conducted to observe the flow around a flat plate for Re of 4.8 × 104 and 7.6 × 104. Two flat plates having thickness ratios of 1% and 3% are considered in the present study. In each case, the trailing edge vortices are studied and the corresponding Strouhal number is calculated. The general observation is that the Strouhal number decreases with the increase of angle of attack. The flat plate with 1% thickness ratio shows a better lift-to-drag ratio than the flat plate with 3% thickness ratio. The pressure distribution along the flat plate has also been plotted and compared to that of a conventional low Re airfoil, S5010. For the Re under investigation, the difference in pressure between the suction and pressure sides is found to be higher for the flat plate at higher AoAs.
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Murphy, Ian P., Shirin Dadashi, Jessica Gregory, Yu Lei, Javid Bayandor, and Andrew Kurdila. "Modeling and Adaptive Control for Tracking Wing Trajectories." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-64925.
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Studies of Micro Air Vehicles (MAVs) have gained increased attention over the past decade, while a significant range of open problems in this emerging field remain unaddressed. This paper highlights the investigations entailing flapping wing vehicles, designed based on inspiration from observations of avian flight. The nonlinear equations of motion of a ground fixed flapping wing robot are derived that incorporates a quasi-steady model of aerodynamics. The equations of motion are developed using Lagrange’s equations and the aerodynamic contributions are formulated using virtual work principles. The aerodynamics are constructed with a quasi-steady state formulation where the functions representing lift and drag coefficients as a function of angle of attack are treated as unknowns. An adaptive controller is introduced that seeks to learn the aerodynamic effects. A Lyapunov analysis of the controller guarantees boundedness of all error terms and asymptotic stability in both the joint position and derivative error. The controllers are simulated using two dynamic models based on flapping wing prototypes designed at Virginia Tech. The numerical experiments validate the Lyapunov analysis and verify that unknown parameters are learned if persistently excited.
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Han, Jae-Hung, Dong-Kyu Lee, Jun-Seong Lee, and Sang-Joon Chung. "Teaching a Micro Air Vehicle How to Fly as We Teach Babies How to Walk." In ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/smasis2011-5026.
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Micro Air Vehicles (MAVs) have become more attractive for various missions including surveillance or reconnaissance in recent years. MAVs should be capable of maintaining their attitudes through either inherent passive stability or active feedback in order to successfully perform their directives. Stability and Controllability Augmentation Systems (SCASs) are usually employed to enhance the flight performance of conventional aircrafts and Unmanned Aerial Vehicles (UAVs). However, it is no simple task to obtain an accurate numerical model for the flight dynamics of a MAV. An alternative approach for SCASs would be to incorporate reinforcement learning in order to address this numerical complexity. Such implementation has already been successful in other vehicles, such as unmanned ground vehicles (UGVs), because of their bettered stability compared to aerial vehicles. However, in order to train MAVs to learn how to fly, they must first be airborne. Similar to teaching infants how to walk, this paper presents a new method to provide an effective environment where a MAV can learn how to fly. A test setup was constructed to enable magnetic levitation of a MAV embedded with a permanent magnet. This apparatus allows for flexible experimentation: the position and the altitude of the MAV, the constraint forces, and the resulting moments are all adjustable and fixable. This ‘Pseudo Flight Environment’ was demonstrated with a fixed wing MAV model. In order for the model to maintain a constant altitude, a height hold control system was devised and implemented.
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Prathapanayaka, Rajeevalochanam, Nanjundaiah Vinod Kumar, Krishnamurthy Settisara Janney, and Hari Krishna Nagishetty. "Design and Analysis Software for Propellers." In ASME 2013 Gas Turbine India Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gtindia2013-3681.
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Recent interest in the field of micro and nano scale air vehicles attracted the attention of many researchers all over the world. The challenge associated with these classes of vehicles is to develop efficient miniaturized components. There are different types of micro and nano air vehicles out of which fixed wing micro air vehicle is one of them. Propulsion system for most of the fixed wing MAVs is propeller driven by an electric motor powered by a battery. The endurance of the MAV mainly depends on the performance of these two components. Hence there is a scope to improve the performance of the propeller and motor. Efficient propeller design and its performance analysis are an iterative process and time consuming. In the present study, to ease the process of propeller design and analysis NALPROPELLER code has been developed using MATLAB. This code is based on minimum induced loss theory presented by E.E.Larrabee to generate planform, blade element momentum theory along with Prandtl hub-tip loss model for overall performance analysis and the performance plots could be viewed in the GUI windows. The code consists of three modules namely single airfoil design, multi airfoil design and analysis module. This code is compared with one of the propeller design and analysis code available in the internet JavaProp by Martin Hepperle, which is also based on minimum induced loss method. From literature Eppler 193 airfoil show high lift to drag ratios at low Reynolds numbers [16]. Eppler-193 airfoil is used in the evaluation of propeller performance. A four inch diameter, two bladed, fixed pitch propeller is designed and analysed using this code. The design is compared with one of the design software JavaProp available online as an open source. A poly urethane casting propeller is fabricated based on the design. The performance comparison of the NALPROPELLER code, JavaProp and 3D CFD analysis is presented and discussed.
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Fuchiwaki, Masaki, Taichi Kuroki, Kazuhiro Tanaka, and Takahide Tabata. "Three-Dimensional Vortex Structure Around a Free Flight Butterfly." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21303.
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Micro-air-vehicles (MAVs) and micro-flight robots that mimic the flight mechanisms of insects have attracted significant attention. From this reason, the flight mechanism of the butterflies and their flow fields also has attracted attention. A number of studies on the mechanism of butterfly flight have been carried out. Moreover, a number of recent studies have examined the flow field around insect wings. The present authors conducted a particle image velocimetry (PIV) measurement around the flapping wings of Cynthia cardui and Idea leuconoe and investigated the vortex structure and dynamic behavior produced. However, these results are for a flow field under a fixed condition. The vortex flow structure and the dynamic behavior generated by the wings of a butterfly in free flight are expected to be important for generating the aerodynamic forces required for flight. In the present study, we attempt to clarify the three-dimensional vortex structure around a butterfly in free flight by a scanning PIV measurement. The vortex ring formed by the front wings during the flapping downward grows without attenuation toward the wake. Moreover, during the flapping upward of the wings, a vortex rolls up from the wing, eventually forming a single vortex ring. This vortex ring forms in the vertical direction in contrast to vortex ring formed during the flapping downward, and we may anticipate that the two vortex rings interfere with each other as they advance toward the wake.
Reports on the topic "Fixed Wing MAVs"
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Billings, Stephen. Wide Area UXO Screening with the Multi-Sensor Fixed-Wing Airborne System MARS. Fort Belvoir, VA: Defense Technical Information Center, February 2008. http://dx.doi.org/10.21236/ada495543.
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Beason, Scott, Taylor Kenyon, Robert Jost, and Laurent Walker. Changes in glacier extents and estimated changes in glacial volume at Mount Rainier National Park, Washington, USA from 1896 to 2021. National Park Service, June 2023. http://dx.doi.org/10.36967/2299328.
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Surface area of glaciers and perennial snow within Mount Rainier National Park were delineated based on 2021 aerial Structure-from-Motion (SfM) and satellite imagery to document changes to glaciers over the last 125 years. These extents were compared with previously completed databases from 1896, 1913, 1971, 1994, 2009, and 2015. In addition to the glacial features mapped at the Park, any snow patches noted in satellite- and fixed-wing- acquired aerial images in September 2021 were mapped as perennial snowfields. In 2021, Mount Rainier National Park contained a total of 28 named glaciers which covered a total of 75.496 ± 4.109 km2 (29.149 ± 1.587 mi2). Perennial snowfields added another 1.938 ± 0.112 km2 (0.748 ± 0.043 mi2), bringing the total perennial snow and glacier cover within the Park in 2021 to 77.434 ± 4.221 km2 (29.897 ± 1.630 mi2). The largest glacier at Mount Rainier was the Emmons Glacier, which encompasses 10.959 ± 0.575 km2 (4.231 ± 0.222 mi2). The change in glacial area from 1896 to 2021 was -53.812 km2 (-20.777 mi2), a total reduction of 41.6%. This corresponds to an average rate of -0.430 km2 per year (-0.166 mi2 × yr-1) during the 125 year period. Recent changes (between the 6-year period of 2015 to 2021) showed a reduction of 3.262 km2 (-1.260 mi2) of glacial area, or a 4.14% reduction at a rate of -0.544 km2 per year ( 0.210 mi2 × yr-1). This rate is 2.23 times that estimated in 2015 (2009-2015) of -0.244 km2 per year (-0.094 mi2 × yr-1). Changes in ice volume at Mount Rainier and estimates of total volumes were calculated for 1896, 1913, 1971, 1994, 2009, 2015, and 2021. Volume change between 1971 and 2007/8 was -0.65 km3 ( 0.16 mi3; Sisson et al., 2011). We used the 2007/8 LiDAR digital elevation model and our 2021 SfM digital surface model to estimate a further loss of -0.404 km3 (-0.097 mi3). In the 50-year period between 1971 and 2021, the glaciers and perennial snowfields of Mount Rainier lost a total of -1.058 km3 (-0.254 mi3) at a rate of -0.021 km3 per year (-0.005 mi3 × yr-1). The calculation of the total volume of the glaciers during various glacier extent inventories at Mount Rainier is not straightforward and various methods are explored in this paper. Using back calculated scaling parameters derived from a single volume measurement in 1971 and estimates completed by other authors, we have developed an estimate of glacial mass during the last 125-years at Mount Rainier that mostly agree with volumetric changes observed in the last 50 years. Because of the high uncertainty with these methods, a relatively modest 35% error is chosen. In 2021, Mount Rainier’s 28 glaciers contain about 3.516 ± 1.231 km3 (0.844 ± 0.295 mi3) of glacial ice, snow, and firn. The change in glacial mass over the 125-year period from 1896 to 2021 was 3.742 km3 (-0.898 mi3), a total reduction of 51.6%, at an average rate of -0.030 km3 per year ( 0.007 mi3 × yr-1). Volume change over the 6-year period of 2015 to 2021 was 0.175 km3 (-0.042 mi3), or a 4.75% reduction, at a rate of -0.029 km3 per year (-0.007 mi3 × yr-1). This survey officially removes one glacier from the Park’s inventory and highlights several other glaciers in a critical state. The Stevens Glacier, an offshoot of the Paradise Glacier on the Park’s south face, was removed due to its lack of features indicating flow, and therefore is no longer a glacier but instead a perennial snowfield. Two other south facing glaciers – the Pyramid and Van Trump glaciers – are in serious peril. In the six-year period between 2015 and 2021, these two glaciers lost 32.9% and 33.6% of their area and 42.0% and 42.9% of their volume, respectively. These glaciers are also becoming exceedingly fragmented and no longer possess what can be called a main body of ice. Continued losses will quickly lead to the demise of these glaciers in the coming decades. Overall, the glaciers on the south face of the mountain have been rapidly shrinking over the last 125 years. Our data shows a continuation of gradual yet accelerating loss of glacial ice at Mount Rainier, resulting in significant changes in regional ice volume over the last century. The long-term impacts of this loss will be widespread and impact many facets of the Park ecosystem. Additionally, rapidly retreating south-facing glaciers are exposing large areas of loose sediment that can be mobilized to proglacial rivers during rainstorms, outburst floods, and debris flows. Regional climate change is affecting all glaciers at Mount Rainier, but especially those smaller cirque glaciers and discontinuous glaciers on the south side of the volcano. If the regional climate trend continues, further loss in glacial area and volume parkwide is anticipated, as well as the complete loss of small glaciers at lower elevations with surface areas less than 0.2 km2 (0.08 mi2) in the next few decades.