Pub Date : 2021-01-01DOI: 10.1177/17568293211055653
D. Kurtulus
The low Reynolds number aerodynamics is important to investigate for micro air vehicle applications. The current paper covers numerical simulations to present the downstream development of the wake patterns and detailed analysis of the vortices generated at the downstream of NACA 0012 airfoil around the critical angle of attack where the instantaneous vortex patterns are oscillatory and differ from the mean vortex pattern for low Reynolds numbers ranging from 1000 to 4000. The instantaneous and mean aerodynamic forces, pressure and skin friction coefficients, and vorticity values are compared in addition to the path of the vortex centers, their longitudinal and lateral spacings, Kármán spacing ratios, and distortion ratios at the wake of the airfoil in regard to the different Reynolds numbers investigated. The streamwise and crosswise velocities of the vortex cores and relative velocities at different transverse locations are also discussed and presented in detail. The correlations between different non-dimensional numbers (St, Re, Ro) are obtained at these low Reynolds numbers investigated.
低雷诺数空气动力学对于微型飞行器的研究具有重要意义。目前的论文涵盖了数值模拟，以呈现尾迹模式的下游发展，并详细分析了NACA 0012翼型下游在临界迎角周围产生的涡，其中瞬时涡型是振荡的，不同于低雷诺数范围从1000到4000的平均涡型。瞬时和平均气动力、压力和表面摩擦系数、涡量值以及涡中心路径、纵向和横向间距、Kármán间距比和不同雷诺数下翼型尾迹的畸变比进行了比较。并详细讨论了涡旋核的流向速度和横向速度以及不同横向位置的相对速度。不同的无量纲数(St, Re, Ro)之间的相关性在这些低雷诺数研究得到。
{"title":"Vortex flow aerodynamics behind a symmetric airfoil at low angles of attack and Reynolds numbers","authors":"D. Kurtulus","doi":"10.1177/17568293211055653","DOIUrl":"https://doi.org/10.1177/17568293211055653","url":null,"abstract":"The low Reynolds number aerodynamics is important to investigate for micro air vehicle applications. The current paper covers numerical simulations to present the downstream development of the wake patterns and detailed analysis of the vortices generated at the downstream of NACA 0012 airfoil around the critical angle of attack where the instantaneous vortex patterns are oscillatory and differ from the mean vortex pattern for low Reynolds numbers ranging from 1000 to 4000. The instantaneous and mean aerodynamic forces, pressure and skin friction coefficients, and vorticity values are compared in addition to the path of the vortex centers, their longitudinal and lateral spacings, Kármán spacing ratios, and distortion ratios at the wake of the airfoil in regard to the different Reynolds numbers investigated. The streamwise and crosswise velocities of the vortex cores and relative velocities at different transverse locations are also discussed and presented in detail. The correlations between different non-dimensional numbers (St, Re, Ro) are obtained at these low Reynolds numbers investigated.","PeriodicalId":49053,"journal":{"name":"International Journal of Micro Air Vehicles","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42941417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.1177/1756829320979955
Zhengyu Qu, Cuichun Li, Yong Hao, Feng Yan, Yanchu Yang
This paper presents the design details and flight tests validation of printed circuit board fabricated micro gliders. The purpose of the micro glider is to be launched from a super pressure balloon at high altitude, glide to the target position to collect data and upload data to the staying balloon. The mission demand requires the micro glider to finish precise landing with small size and low fabrication cost. To complete this concept, we designed a PCB fabricated aircraft with limited sensors including GPS and IMU. The first part of the article describes the aerodynamic design methods. The second part introduced the control and guidance system design by controlling the roll angle and flight path angle to complete the precise landing. In the simulation results presented in the third part, launch with no wind condition shows desirable precise landing ability. As a contrast, wind direction and magnitude have significant effects on the guidance ability and accuracy. In the last part, two real flight tests conducted in Inner Mongolia of China are described to compare the flight performance with the current aerodynamics and control system design. Returned data indicated the micro gliders could successfully fly at high altitude. The control algorithm can compute the command roll angle only with GPS and IMU, but some design details still need to be improved to achieve precise landing ability.
{"title":"Project of high altitude balloon launched micro glider: Aircraft design, control and flight test","authors":"Zhengyu Qu, Cuichun Li, Yong Hao, Feng Yan, Yanchu Yang","doi":"10.1177/1756829320979955","DOIUrl":"https://doi.org/10.1177/1756829320979955","url":null,"abstract":"This paper presents the design details and flight tests validation of printed circuit board fabricated micro gliders. The purpose of the micro glider is to be launched from a super pressure balloon at high altitude, glide to the target position to collect data and upload data to the staying balloon. The mission demand requires the micro glider to finish precise landing with small size and low fabrication cost. To complete this concept, we designed a PCB fabricated aircraft with limited sensors including GPS and IMU. The first part of the article describes the aerodynamic design methods. The second part introduced the control and guidance system design by controlling the roll angle and flight path angle to complete the precise landing. In the simulation results presented in the third part, launch with no wind condition shows desirable precise landing ability. As a contrast, wind direction and magnitude have significant effects on the guidance ability and accuracy. In the last part, two real flight tests conducted in Inner Mongolia of China are described to compare the flight performance with the current aerodynamics and control system design. Returned data indicated the micro gliders could successfully fly at high altitude. The control algorithm can compute the command roll angle only with GPS and IMU, but some design details still need to be improved to achieve precise landing ability.","PeriodicalId":49053,"journal":{"name":"International Journal of Micro Air Vehicles","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1756829320979955","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43379522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-01DOI: 10.1177/1756829320977989
Han Bao, Wenqing Yang, D. Ma, Wenping Song, Bifeng Song
Bionic micro aerial vehicles have become popular because of their high thrust efficiency and deceptive appearances. Leading edge or trailing edge devices (such as slots or flaps) are often used to improve the flight performance. Birds in nature also have leading-edge devices, known as the alula that can improve their flight performance at large angles of attack. In the present study, the aerodynamic performance of a flapping airfoil with alula is numerically simulated to illustrate the effects of different alula geometric parameters. Different alula relative angles of attack β (the angle between the chord line of the alula and that of the main airfoil) and vertical distances h between the alula and the main airfoil are simulated at pre-stall and post-stall conditions. Results show that at pre-stall condition, the lift increases with the relative angle of attack and the vertical distance, but the aerodynamic performance is degraded in the presence of alula compared with no alula, whereas at post-stall condition, the alula greatly enhances the lift. However, there seems to be an optimal relative angle of attack for the maximum lift enhancement at a fixed vertical distance considering the unsteady effect, which may indicate birds can adjust the alula twisting at different spanwise positions to achieve the best flight performance. Different alula geometric parameters may affect the aerodynamic force by modifying the pressure distribution along the airfoil. The results are instructive for design of flapping-wing bionic unmanned air vehicles.
{"title":"Numerical simulation of flapping airfoil with alula","authors":"Han Bao, Wenqing Yang, D. Ma, Wenping Song, Bifeng Song","doi":"10.1177/1756829320977989","DOIUrl":"https://doi.org/10.1177/1756829320977989","url":null,"abstract":"Bionic micro aerial vehicles have become popular because of their high thrust efficiency and deceptive appearances. Leading edge or trailing edge devices (such as slots or flaps) are often used to improve the flight performance. Birds in nature also have leading-edge devices, known as the alula that can improve their flight performance at large angles of attack. In the present study, the aerodynamic performance of a flapping airfoil with alula is numerically simulated to illustrate the effects of different alula geometric parameters. Different alula relative angles of attack β (the angle between the chord line of the alula and that of the main airfoil) and vertical distances h between the alula and the main airfoil are simulated at pre-stall and post-stall conditions. Results show that at pre-stall condition, the lift increases with the relative angle of attack and the vertical distance, but the aerodynamic performance is degraded in the presence of alula compared with no alula, whereas at post-stall condition, the alula greatly enhances the lift. However, there seems to be an optimal relative angle of attack for the maximum lift enhancement at a fixed vertical distance considering the unsteady effect, which may indicate birds can adjust the alula twisting at different spanwise positions to achieve the best flight performance. Different alula geometric parameters may affect the aerodynamic force by modifying the pressure distribution along the airfoil. The results are instructive for design of flapping-wing bionic unmanned air vehicles.","PeriodicalId":49053,"journal":{"name":"International Journal of Micro Air Vehicles","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1756829320977989","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48963581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-01DOI: 10.1177/1756829320973579
E. J. Ollervides-Vazquez, E. G. Rojo-Rodriguez, O. Garcia-Salazar, L. Amezquita-Brooks, P. Castillo, V. Santibáñez
This paper presents an algorithm based on fuzzy theory for the formation flight of the multi-quadrotors. For this purpose, the mathematical model of N-quadrotor unmanned aerial vehicles is presented using the Newton-Euler formulation. The strategy of the formation flight is based on a structure composed by a sectorial fuzzy controller and the linear systems whose state variables are the position and velocity of the ith quadrotor. The stability analysis is described as a generalized form for N-quadrotor unmanned aerial vehicles and it is based on the Lyapunov theory. This analysis demonstrates that the closed-loop system is globally asymptotically stable so that the quadrotors unmanned aerial vehicles reach the consensus. Numerical simulation demonstrates the robustness of the proposed scheme for the formation flight even in the presence of disturbances. Finally, experimental results show the feasibility of the proposed algorithm for the formation flight of multiple unmanned aerial vehicles.
{"title":"A sectorial fuzzy consensus algorithm for the formation flight of multiple quadrotor unmanned aerial vehicles","authors":"E. J. Ollervides-Vazquez, E. G. Rojo-Rodriguez, O. Garcia-Salazar, L. Amezquita-Brooks, P. Castillo, V. Santibáñez","doi":"10.1177/1756829320973579","DOIUrl":"https://doi.org/10.1177/1756829320973579","url":null,"abstract":"This paper presents an algorithm based on fuzzy theory for the formation flight of the multi-quadrotors. For this purpose, the mathematical model of N-quadrotor unmanned aerial vehicles is presented using the Newton-Euler formulation. The strategy of the formation flight is based on a structure composed by a sectorial fuzzy controller and the linear systems whose state variables are the position and velocity of the ith quadrotor. The stability analysis is described as a generalized form for N-quadrotor unmanned aerial vehicles and it is based on the Lyapunov theory. This analysis demonstrates that the closed-loop system is globally asymptotically stable so that the quadrotors unmanned aerial vehicles reach the consensus. Numerical simulation demonstrates the robustness of the proposed scheme for the formation flight even in the presence of disturbances. Finally, experimental results show the feasibility of the proposed algorithm for the formation flight of multiple unmanned aerial vehicles.","PeriodicalId":49053,"journal":{"name":"International Journal of Micro Air Vehicles","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1756829320973579","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48728302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-01DOI: 10.1177/1756829320943085
Shaoran Liang, Bifeng Song, J. Xuan, Yubin Li
This paper proposes an attitude control scheme for the Dove flapping wing micro air vehicle in intermittent flapping and gliding flight. The Dove flapping wing micro air vehicle adopts intermittent flapping and gliding flight to make the wing movements more natural; this strategy also has the potential to reduce energy consumption. To implement this specific flight mode, this paper proposes a closed-loop active disturbance rejection control strategy to stabilize the attitude during the processes of flapping flight, transition and gliding flight. The active disturbance rejection control controller is composed of three parts: a tracking differentiator, a linear extended state observer and a nonlinear state error feedback controller. The tracking differentiator estimates the given target signal and the differential signal in real time. The extended state observer estimates the system states and system nonlinearity. Moreover, the bandwidth parameterization method is applied to determine the observer gains. The stability of the closed-loop system is verified using Lyapunov’s theorem. Several outdoor flight experiments have been conducted to verify the effectiveness of the proposed control method, and the results show that the proposed method can guarantee the stability of intermittent flapping and gliding flight.
{"title":"Active disturbance rejection attitude control for the dove flapping wing micro air vehicle in intermittent flapping and gliding flight","authors":"Shaoran Liang, Bifeng Song, J. Xuan, Yubin Li","doi":"10.1177/1756829320943085","DOIUrl":"https://doi.org/10.1177/1756829320943085","url":null,"abstract":"This paper proposes an attitude control scheme for the Dove flapping wing micro air vehicle in intermittent flapping and gliding flight. The Dove flapping wing micro air vehicle adopts intermittent flapping and gliding flight to make the wing movements more natural; this strategy also has the potential to reduce energy consumption. To implement this specific flight mode, this paper proposes a closed-loop active disturbance rejection control strategy to stabilize the attitude during the processes of flapping flight, transition and gliding flight. The active disturbance rejection control controller is composed of three parts: a tracking differentiator, a linear extended state observer and a nonlinear state error feedback controller. The tracking differentiator estimates the given target signal and the differential signal in real time. The extended state observer estimates the system states and system nonlinearity. Moreover, the bandwidth parameterization method is applied to determine the observer gains. The stability of the closed-loop system is verified using Lyapunov’s theorem. Several outdoor flight experiments have been conducted to verify the effectiveness of the proposed control method, and the results show that the proposed method can guarantee the stability of intermittent flapping and gliding flight.","PeriodicalId":49053,"journal":{"name":"International Journal of Micro Air Vehicles","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1756829320943085","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48946703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-01DOI: 10.1177/1756829320941005
Ana Guerra-Langan, S. Araujo-Estrada, S. Windsor
Small unmanned aerial vehicles (SUAVs) are suitable for many low-altitude operations in urban environments due to their manoeuvrability; however, their flight performance is limited by their on-board energy storage and their ability to cope with high levels of turbulence. Birds exploit the atmospheric boundary layer in urban environments, reducing their energetic flight costs by using orographic lift generated by buildings. This behaviour could be mimicked by fixed-wing SUAVs to overcome their energy limitations if flight control can be maintained in the increased turbulence present in these conditions. Here, the control effort required and energetic benefits for a SUAV flying parallel to buildings whilst using orographic lift was investigated. A flight dynamics and control model was developed for a powered SUAV and used to simulate flight control performance in different turbulent wind conditions. It was found that the control effort required decreased with increasing altitude and that the mean throttle required increased with greater radial distance to the buildings. However, the simulations showed that flying close to the buildings in strong wind speeds increased the risk of collision. Overall, the results suggested that a strategy of flying directly over the front corner of the buildings appears to minimise the control effort required for a given level of orographic lift, a strategy that mirrors the behaviour of gulls in high wind speeds.
{"title":"Unmanned aerial vehicle control costs mirror bird behaviour when soaring close to buildings","authors":"Ana Guerra-Langan, S. Araujo-Estrada, S. Windsor","doi":"10.1177/1756829320941005","DOIUrl":"https://doi.org/10.1177/1756829320941005","url":null,"abstract":"Small unmanned aerial vehicles (SUAVs) are suitable for many low-altitude operations in urban environments due to their manoeuvrability; however, their flight performance is limited by their on-board energy storage and their ability to cope with high levels of turbulence. Birds exploit the atmospheric boundary layer in urban environments, reducing their energetic flight costs by using orographic lift generated by buildings. This behaviour could be mimicked by fixed-wing SUAVs to overcome their energy limitations if flight control can be maintained in the increased turbulence present in these conditions. Here, the control effort required and energetic benefits for a SUAV flying parallel to buildings whilst using orographic lift was investigated. A flight dynamics and control model was developed for a powered SUAV and used to simulate flight control performance in different turbulent wind conditions. It was found that the control effort required decreased with increasing altitude and that the mean throttle required increased with greater radial distance to the buildings. However, the simulations showed that flying close to the buildings in strong wind speeds increased the risk of collision. Overall, the results suggested that a strategy of flying directly over the front corner of the buildings appears to minimise the control effort required for a given level of orographic lift, a strategy that mirrors the behaviour of gulls in high wind speeds.","PeriodicalId":49053,"journal":{"name":"International Journal of Micro Air Vehicles","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1756829320941005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46588975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-01DOI: 10.1177/1756829320927593
P. Campoy, P. de la Puente, Adrian Carrio
{"title":"Editorial","authors":"P. Campoy, P. de la Puente, Adrian Carrio","doi":"10.1177/1756829320927593","DOIUrl":"https://doi.org/10.1177/1756829320927593","url":null,"abstract":"","PeriodicalId":49053,"journal":{"name":"International Journal of Micro Air Vehicles","volume":"12 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1756829320927593","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41784700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-01DOI: 10.1177/1756829320923563
L. Ding, Yangmin Li
The robust control problem in attitude tracking of an unmanned aerial vehicle quadrotor is a challenging task due to strong parametric uncertainties, large nonlinearities and high couplings in flight dynamics. In this paper, a continuous nonsingular fast terminal sliding mode controller based on linear extended state observer is proposed for attitude tracking control of a quadrotor under lumped disturbances. The proposed control method requires no prior knowledge of the attitude dynamics. It can ensure rapid convergence rate and high tracking precision due to terminal sliding mode surface and fast reaching law. The controller uses the linear extended state observer to reject the influence of both parametric uncertainties and external disturbances. Meanwhile, the nonsingular fast terminal sliding mode control strategy is designed to ensure the state variables to slide to desired points in finite time. To enhance the control performance, a self-adaptive fruit fly optimization algorithm is applied to parameters tuning of the proposed controller. The effectiveness of the proposed control approach is illustrated through numerical simulations and experimental verification.
{"title":"Optimal attitude tracking control for an unmanned aerial quadrotor under lumped disturbances","authors":"L. Ding, Yangmin Li","doi":"10.1177/1756829320923563","DOIUrl":"https://doi.org/10.1177/1756829320923563","url":null,"abstract":"The robust control problem in attitude tracking of an unmanned aerial vehicle quadrotor is a challenging task due to strong parametric uncertainties, large nonlinearities and high couplings in flight dynamics. In this paper, a continuous nonsingular fast terminal sliding mode controller based on linear extended state observer is proposed for attitude tracking control of a quadrotor under lumped disturbances. The proposed control method requires no prior knowledge of the attitude dynamics. It can ensure rapid convergence rate and high tracking precision due to terminal sliding mode surface and fast reaching law. The controller uses the linear extended state observer to reject the influence of both parametric uncertainties and external disturbances. Meanwhile, the nonsingular fast terminal sliding mode control strategy is designed to ensure the state variables to slide to desired points in finite time. To enhance the control performance, a self-adaptive fruit fly optimization algorithm is applied to parameters tuning of the proposed controller. The effectiveness of the proposed control approach is illustrated through numerical simulations and experimental verification.","PeriodicalId":49053,"journal":{"name":"International Journal of Micro Air Vehicles","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1756829320923563","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49569750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-01DOI: 10.1177/1756829320925748
A. Cabrera-Ponce, J. Martínez-Carranza, C. Rascón
In this work, we address the problem of UAV detection flying nearby another UAV. Usually, computer vision could be used to face this problem by placing cameras onboard the patrolling UAV. However, visual processing is prone to false positives, sensible to light conditions and potentially slow if the image resolution is high. Thus, we propose to carry out the detection by using an array of microphones mounted with a special array onboard the patrolling UAV. To achieve our goal, we convert audio signals into spectrograms and used them in combination with a CNN architecture that has been trained to learn when a UAV is flying nearby, and when it is not. Clearly, the first challenge is the presence of ego-noise derived from the patrolling UAV itself through its propellers and motor’s noise. Our proposed CNN is based on Google’s Inception v.3 network. The Inception model is trained with a dataset created by us, which includes examples of when an intruder UAV flies nearby and when it does not. We conducted experiments for off-line and on-line detection. For the latter, we manage to generate spectrograms from the audio stream and process it with the Nvidia Jetson TX2 mounted onboard the patrolling UAV.
{"title":"Detection of nearby UAVs using a multi-microphone array on board a UAV","authors":"A. Cabrera-Ponce, J. Martínez-Carranza, C. Rascón","doi":"10.1177/1756829320925748","DOIUrl":"https://doi.org/10.1177/1756829320925748","url":null,"abstract":"In this work, we address the problem of UAV detection flying nearby another UAV. Usually, computer vision could be used to face this problem by placing cameras onboard the patrolling UAV. However, visual processing is prone to false positives, sensible to light conditions and potentially slow if the image resolution is high. Thus, we propose to carry out the detection by using an array of microphones mounted with a special array onboard the patrolling UAV. To achieve our goal, we convert audio signals into spectrograms and used them in combination with a CNN architecture that has been trained to learn when a UAV is flying nearby, and when it is not. Clearly, the first challenge is the presence of ego-noise derived from the patrolling UAV itself through its propellers and motor’s noise. Our proposed CNN is based on Google’s Inception v.3 network. The Inception model is trained with a dataset created by us, which includes examples of when an intruder UAV flies nearby and when it does not. We conducted experiments for off-line and on-line detection. For the latter, we manage to generate spectrograms from the audio stream and process it with the Nvidia Jetson TX2 mounted onboard the patrolling UAV.","PeriodicalId":49053,"journal":{"name":"International Journal of Micro Air Vehicles","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1756829320925748","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42580967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-01DOI: 10.1177/1756829320923565
B. Theys, J. De Schutter
This paper presents experimental results on the relation between forward airspeed, pitch angle, and power consumption of a quadcopter unmanned aerial vehicle. The quadcopter consists of an interchangeable spherical body, four cylindrical arms, and small propellers mounted at 1 m diagonal distance to minimize interference between body and propellers. This simple geometry facilitates results reproduction and comparison with simulation. Two different takeoff masses and four diameters of spherical bodies are tested for their steady-state speed and power for pitch angles up to − 45 ° . The steady-state horizontal flight is recorded with on-board sensors at the end of flying long straight lines at a constant pitch angle in wind-still conditions. The best effective lift-to-drag ratio increases for smaller bodies and occurs at higher speeds for increasing mass. Results show that the equivalent frontal surface stays constant for pitch angles further than − 5 ° up to the maximum recorded − 45 ° and increases linearly with the frontal surface of the body.
{"title":"Forward flight tests of a quadcopter unmanned aerial vehicle with various spherical body diameters","authors":"B. Theys, J. De Schutter","doi":"10.1177/1756829320923565","DOIUrl":"https://doi.org/10.1177/1756829320923565","url":null,"abstract":"This paper presents experimental results on the relation between forward airspeed, pitch angle, and power consumption of a quadcopter unmanned aerial vehicle. The quadcopter consists of an interchangeable spherical body, four cylindrical arms, and small propellers mounted at 1 m diagonal distance to minimize interference between body and propellers. This simple geometry facilitates results reproduction and comparison with simulation. Two different takeoff masses and four diameters of spherical bodies are tested for their steady-state speed and power for pitch angles up to − 45 ° . The steady-state horizontal flight is recorded with on-board sensors at the end of flying long straight lines at a constant pitch angle in wind-still conditions. The best effective lift-to-drag ratio increases for smaller bodies and occurs at higher speeds for increasing mass. Results show that the equivalent frontal surface stays constant for pitch angles further than − 5 ° up to the maximum recorded − 45 ° and increases linearly with the frontal surface of the body.","PeriodicalId":49053,"journal":{"name":"International Journal of Micro Air Vehicles","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1756829320923565","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45062437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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