An attempt is made to apply modern control technology to the roll and yaw control of a rudderless quad-tiltrotor Unmanned Aerial Vehicle(UAV)in the latter part of the flight mode transition,where aerodynamic forces on...An attempt is made to apply modern control technology to the roll and yaw control of a rudderless quad-tiltrotor Unmanned Aerial Vehicle(UAV)in the latter part of the flight mode transition,where aerodynamic forces on the tiltrotor’s wings start to take effect.A predictor-based adaptive roll and yaw controller is designed to compensate for system uncertainties and parameter changes.A dynamics model of the tiltrotor is built.A Radial-Basis Function(RBF)neural network and offline adaptation method are used to reduce flight controller workload and cope with the nonlinearities in the controls.Simulations are conducted to verify the reference model response tracking and yaw-roll control decoupling ability of the adaptive controller,as well as the validity of the offline adaptation method.Flight tests are conducted to confirm the ability of the adaptive controller to track different roll and yaw reference model responses.The decoupling of roll and yaw controls is also tested in flight via coordinated turn maneuvers with different rotor tilt angles.展开更多
The conceptual design and optimization of a tilt-rotor Micro Air Vehicle(MAV) for a well-defined mission are performed. The objective of this design cycle is to decrease the design time in order to efficiently create ...The conceptual design and optimization of a tilt-rotor Micro Air Vehicle(MAV) for a well-defined mission are performed. The objective of this design cycle is to decrease the design time in order to efficiently create a functional tilt-rotor drone. A flight mission is firstly defined for a tiltrotor MAV performing hovering and cruise flight scenarios. Secondly, a complex wing shape is chosen and modeled in order to determine the final shape. The initial shape is scaled in order to acquire an arbitrary wingspan of one meter. For the specific area and wingspan, the aspect ratio of the designed wing shape is found to be equal to 2.32. Thirdly, a constraint analysis of the MAV is performed by using an energy balance analysis for six different flight scenarios. This analysis yields the required power loading and wing loading. Fourthly, the weight of the vehicle is estimated using both statistical and computational methods. After estimating the total weight and the wing loading of the MAV, the surface of the wing is determined, yielding a final wingspan of 0.76 m. Subsequently, considering the total weight of the designed MAV, the needed lift coefficient is determined.Fifthly, using the lift coefficient in conjunction with XLFR5, a batch of airfoils is selected and analyzed to evaluate the aerodynamic coefficients of the wing with each airfoil. This analysis ultimately leads to the optimum airfoil being selected. Finally, design of the fuselage and tail, internal components selection, and servo-mechanisms design are carried out prior to a stability analysis. All these proposed steps are needed to design efficient and functional tilt-rotor MAVs.展开更多
Overall, this paper explains the related information about VTOL and trend of this technology worldwide. Also, it comes up with the distinction among VTOL and helicopter and fixed wing aircraft. This paper concentrates...Overall, this paper explains the related information about VTOL and trend of this technology worldwide. Also, it comes up with the distinction among VTOL and helicopter and fixed wing aircraft. This paper concentrates on domestic and international drones that utilize VTOL technology. Also, this paper gives the explanation about VTOL’s performance and object. Furthermore, this paper predicts the future of VTOL and which area this technology going to be used.展开更多
China’s reusable carrier rocket completes first 10-km VTOL test China’s reusable carrier rocket successfully completed a 10-km vertical take-off and landing(VTOL)flight test at the Jiuquan Satellite Launch Center in...China’s reusable carrier rocket completes first 10-km VTOL test China’s reusable carrier rocket successfully completed a 10-km vertical take-off and landing(VTOL)flight test at the Jiuquan Satellite Launch Center in northwest China on June 23.展开更多
Ducted fans have been widely used in VTOL aircraft due to the high propulsion efficiency and safety.The efficiency and stability of ducted fans deteriorate in some flight conditions such as hovering in crosswinds or g...Ducted fans have been widely used in VTOL aircraft due to the high propulsion efficiency and safety.The efficiency and stability of ducted fans deteriorate in some flight conditions such as hovering in crosswinds or ground effect.It is necessary to optimize the ducted fan’s structures or apply flow control methods for better adaptions to the typical conditions.This paper presents a detailed review on the ducted fan technology for VTOL applications,especially the methods for improving its efficiency and stability.We first simplified the classification categories based on boundary conditions instead of flight conditions,since the new classification method covers more situations and is easier to distinguish flow field characteristics.The flow characteristics,thrust properties and the optimal structures under different boundary conditions were summarized and discussed.Finally,new configurations and flow control methods for increasing the efficiency and stability were introduced.The newly proposed integration design between the ducted fan and the motor was emphasized for increasing the power density of the ducted fans.This review would be helpful to improve our understanding of the relationship between the structures,flow characteristics and thrust properties of ducted fans under different flight conditions,and inspires scientists to design high-efficiency and high-stability propulsion systems with ducted fans.展开更多
The utilization of UAVs (Unmanned Aerial Vehicles) has experienced a remarkable upsurge in various industries, including forestry. Their capacity to expeditiously and effectively cover large tracts of land has resulte...The utilization of UAVs (Unmanned Aerial Vehicles) has experienced a remarkable upsurge in various industries, including forestry. Their capacity to expeditiously and effectively cover large tracts of land has resulted in their widespread adoption as a valuable forest management and monitoring tool. The versatility of UAVs extends to their capability to perform quick and efficient surveys of large areas, inventory of tree species, and monitoring of forest health. This research paper reports on the successful utilization of VTOL (Vertical Takeoff and Landing) UAV that was designed and built at the IESSD (Institute of Earth Science and Sustainable Development) located in the AAA (Asia Aviation Academy) at KMITL (King Mongkut’s Institute of Technology Ladkrabang) Prince of Chumphon Campus, Thailand. The VTOL UAV is employed for resource and environmental missions, as well as forest monitoring by using remote sensing technology. VTOL UAVs are used for aerial surveillance to conduct air photography, data collection, and processing for resource and environmental missions. This research paper presents a comprehensive analysis of the areas at risk of deforestation and forest encroachment in a particular region of Khao Yai National Park in Thailand, highlighting the potential for the resulting photographs to inform evidence-based decision-making and facilitate sustainable forest management practices. This study offers recommendations to develop VTOL UAVs remote sensing capabilities and mitigate deforestation and forest encroachment in Khao Yai National Park.展开更多
Recently, the surge in the interests in unmanned aerial vehicles has soared dra-matically worldwide due to many potential benefits foreseen by this technology. The most widespread use of the commercial drones is a mul...Recently, the surge in the interests in unmanned aerial vehicles has soared dra-matically worldwide due to many potential benefits foreseen by this technology. The most widespread use of the commercial drones is a multi-copter form of unmanned aerial vehicle, because of its vertical takeoff and landing (VTOL) capability. However, due to the structural characteristics, it has a disadvantage that the flight time is quite short, which is typically ranging between 15 to 30 minutes. The fixed wing type of unmanned aerial vehicles has a longer flight time and duration, but it is not easy to secure a safe landing space, especially in the city areas. For this reason, demand for vertical fixed take-off and landing aircraft is rapidly increasing throughout the world. This study analyzes the trends and recent development of global VTOL technology and provides a direction into which the current state of the technology should be heading. By comparing the advantage and disadvantage of various VTOP propulsion types, we can clearly identify the most effective form of VTOL propulsion types. Such analysis will be highly beneficial to the drone researchers and scientists in terms of future development.展开更多
There remains a need to develop improved VTOL techniques that are cost-effective and with minimum compromise on cruising flight performance for fixed-wing aircraft. This work proposes an elegant VTOL control method kn...There remains a need to develop improved VTOL techniques that are cost-effective and with minimum compromise on cruising flight performance for fixed-wing aircraft. This work proposes an elegant VTOL control method known as PTVC-M (pitch-axis thrust vector control with moment arms) for tailsitters. The hallmark of the approach is the complete elimination of control surfaces such as elevators and rudder. Computer simulations with a 1580 mm wing span airplane reveal that the proposed technique results in authoritative control and unique maneuverability such as inverted vertical hover and stall-spin with positive climb rate. Zero-surface requirement of the PTVC-M virtually eliminates performance tradeoffs between VTOL and high-speed flight. In this proof-of-concept study, the VTOL-capable aircraft achieves a VH of 360 km·h<sup>-1</sup> at near sea-level. The proposed technique will benefit a broad range of applications including high-performance spinsonde that can directly measure 10-m surface wind, tropical cyclone research, and possibly serving as the cornerstone for the next-generation sport aerobatics.展开更多
Methodological issues associated with the determination of the vertical take-off and landing aerodynamic parameters equipped with two rotary propellers during take-off and hovering, descent and landing are studied in ...Methodological issues associated with the determination of the vertical take-off and landing aerodynamic parameters equipped with two rotary propellers during take-off and hovering, descent and landing are studied in the proposed article. During the computer simulation process, kinematics parameters diagrams were made, aerodynamic coefficients and propellers thrust components at all stages of aircraft take-off were estimated. That numerical data can be used in a preliminary stage of aerodynamic design for the vertical take-off and landing aircraft and electric drones at the determination of control and equalization elements geometric and kinematic parameters.展开更多
There are fundamental performance compromises between rotary-wing and fixed-wing UAVs. The general solution to address this well-known problem is the design of a platform with some degree of reconfigurable airframes. ...There are fundamental performance compromises between rotary-wing and fixed-wing UAVs. The general solution to address this well-known problem is the design of a platform with some degree of reconfigurable airframes. For critical missions (civilian or military), it is imperative that mechanical complexity is kept to a minimum to help achieve mission success. This work proposes that the tried-and-true radio controlled (RC) aerobatic airplanes can be implemented as basis for fixed-wing UAVs having both speed and vertical takeoff and landing (VTOL) capabilities. These powerful and highly maneuverable airplanes have non-rotatable nacelles, yet capable of deep stall maneuvers. The power requirements for VTOL and level flight of an aerobatic RC airplane are evaluated and they are compared to those of a RC helicopter of similar flying weight. This work provides quantitative validation that commercially available RC aerobatic airplanes can serve as platform to build VTOL capable fixed-wing UAVs that are agile, cost effective, reliable and easy maintenance.展开更多
文摘An attempt is made to apply modern control technology to the roll and yaw control of a rudderless quad-tiltrotor Unmanned Aerial Vehicle(UAV)in the latter part of the flight mode transition,where aerodynamic forces on the tiltrotor’s wings start to take effect.A predictor-based adaptive roll and yaw controller is designed to compensate for system uncertainties and parameter changes.A dynamics model of the tiltrotor is built.A Radial-Basis Function(RBF)neural network and offline adaptation method are used to reduce flight controller workload and cope with the nonlinearities in the controls.Simulations are conducted to verify the reference model response tracking and yaw-roll control decoupling ability of the adaptive controller,as well as the validity of the offline adaptation method.Flight tests are conducted to confirm the ability of the adaptive controller to track different roll and yaw reference model responses.The decoupling of roll and yaw controls is also tested in flight via coordinated turn maneuvers with different rotor tilt angles.
基金the financial support from New Mexico Space Grant Consortium
文摘The conceptual design and optimization of a tilt-rotor Micro Air Vehicle(MAV) for a well-defined mission are performed. The objective of this design cycle is to decrease the design time in order to efficiently create a functional tilt-rotor drone. A flight mission is firstly defined for a tiltrotor MAV performing hovering and cruise flight scenarios. Secondly, a complex wing shape is chosen and modeled in order to determine the final shape. The initial shape is scaled in order to acquire an arbitrary wingspan of one meter. For the specific area and wingspan, the aspect ratio of the designed wing shape is found to be equal to 2.32. Thirdly, a constraint analysis of the MAV is performed by using an energy balance analysis for six different flight scenarios. This analysis yields the required power loading and wing loading. Fourthly, the weight of the vehicle is estimated using both statistical and computational methods. After estimating the total weight and the wing loading of the MAV, the surface of the wing is determined, yielding a final wingspan of 0.76 m. Subsequently, considering the total weight of the designed MAV, the needed lift coefficient is determined.Fifthly, using the lift coefficient in conjunction with XLFR5, a batch of airfoils is selected and analyzed to evaluate the aerodynamic coefficients of the wing with each airfoil. This analysis ultimately leads to the optimum airfoil being selected. Finally, design of the fuselage and tail, internal components selection, and servo-mechanisms design are carried out prior to a stability analysis. All these proposed steps are needed to design efficient and functional tilt-rotor MAVs.
文摘Overall, this paper explains the related information about VTOL and trend of this technology worldwide. Also, it comes up with the distinction among VTOL and helicopter and fixed wing aircraft. This paper concentrates on domestic and international drones that utilize VTOL technology. Also, this paper gives the explanation about VTOL’s performance and object. Furthermore, this paper predicts the future of VTOL and which area this technology going to be used.
文摘China’s reusable carrier rocket completes first 10-km VTOL test China’s reusable carrier rocket successfully completed a 10-km vertical take-off and landing(VTOL)flight test at the Jiuquan Satellite Launch Center in northwest China on June 23.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFC1512500)the Advanced Aviation Power Innovation Institution,the Aero Engine Academy of ChinaTsinghua University Initiative Scientific Research Program。
文摘Ducted fans have been widely used in VTOL aircraft due to the high propulsion efficiency and safety.The efficiency and stability of ducted fans deteriorate in some flight conditions such as hovering in crosswinds or ground effect.It is necessary to optimize the ducted fan’s structures or apply flow control methods for better adaptions to the typical conditions.This paper presents a detailed review on the ducted fan technology for VTOL applications,especially the methods for improving its efficiency and stability.We first simplified the classification categories based on boundary conditions instead of flight conditions,since the new classification method covers more situations and is easier to distinguish flow field characteristics.The flow characteristics,thrust properties and the optimal structures under different boundary conditions were summarized and discussed.Finally,new configurations and flow control methods for increasing the efficiency and stability were introduced.The newly proposed integration design between the ducted fan and the motor was emphasized for increasing the power density of the ducted fans.This review would be helpful to improve our understanding of the relationship between the structures,flow characteristics and thrust properties of ducted fans under different flight conditions,and inspires scientists to design high-efficiency and high-stability propulsion systems with ducted fans.
文摘The utilization of UAVs (Unmanned Aerial Vehicles) has experienced a remarkable upsurge in various industries, including forestry. Their capacity to expeditiously and effectively cover large tracts of land has resulted in their widespread adoption as a valuable forest management and monitoring tool. The versatility of UAVs extends to their capability to perform quick and efficient surveys of large areas, inventory of tree species, and monitoring of forest health. This research paper reports on the successful utilization of VTOL (Vertical Takeoff and Landing) UAV that was designed and built at the IESSD (Institute of Earth Science and Sustainable Development) located in the AAA (Asia Aviation Academy) at KMITL (King Mongkut’s Institute of Technology Ladkrabang) Prince of Chumphon Campus, Thailand. The VTOL UAV is employed for resource and environmental missions, as well as forest monitoring by using remote sensing technology. VTOL UAVs are used for aerial surveillance to conduct air photography, data collection, and processing for resource and environmental missions. This research paper presents a comprehensive analysis of the areas at risk of deforestation and forest encroachment in a particular region of Khao Yai National Park in Thailand, highlighting the potential for the resulting photographs to inform evidence-based decision-making and facilitate sustainable forest management practices. This study offers recommendations to develop VTOL UAVs remote sensing capabilities and mitigate deforestation and forest encroachment in Khao Yai National Park.
文摘Recently, the surge in the interests in unmanned aerial vehicles has soared dra-matically worldwide due to many potential benefits foreseen by this technology. The most widespread use of the commercial drones is a multi-copter form of unmanned aerial vehicle, because of its vertical takeoff and landing (VTOL) capability. However, due to the structural characteristics, it has a disadvantage that the flight time is quite short, which is typically ranging between 15 to 30 minutes. The fixed wing type of unmanned aerial vehicles has a longer flight time and duration, but it is not easy to secure a safe landing space, especially in the city areas. For this reason, demand for vertical fixed take-off and landing aircraft is rapidly increasing throughout the world. This study analyzes the trends and recent development of global VTOL technology and provides a direction into which the current state of the technology should be heading. By comparing the advantage and disadvantage of various VTOP propulsion types, we can clearly identify the most effective form of VTOL propulsion types. Such analysis will be highly beneficial to the drone researchers and scientists in terms of future development.
文摘There remains a need to develop improved VTOL techniques that are cost-effective and with minimum compromise on cruising flight performance for fixed-wing aircraft. This work proposes an elegant VTOL control method known as PTVC-M (pitch-axis thrust vector control with moment arms) for tailsitters. The hallmark of the approach is the complete elimination of control surfaces such as elevators and rudder. Computer simulations with a 1580 mm wing span airplane reveal that the proposed technique results in authoritative control and unique maneuverability such as inverted vertical hover and stall-spin with positive climb rate. Zero-surface requirement of the PTVC-M virtually eliminates performance tradeoffs between VTOL and high-speed flight. In this proof-of-concept study, the VTOL-capable aircraft achieves a VH of 360 km·h<sup>-1</sup> at near sea-level. The proposed technique will benefit a broad range of applications including high-performance spinsonde that can directly measure 10-m surface wind, tropical cyclone research, and possibly serving as the cornerstone for the next-generation sport aerobatics.
文摘Methodological issues associated with the determination of the vertical take-off and landing aerodynamic parameters equipped with two rotary propellers during take-off and hovering, descent and landing are studied in the proposed article. During the computer simulation process, kinematics parameters diagrams were made, aerodynamic coefficients and propellers thrust components at all stages of aircraft take-off were estimated. That numerical data can be used in a preliminary stage of aerodynamic design for the vertical take-off and landing aircraft and electric drones at the determination of control and equalization elements geometric and kinematic parameters.
文摘There are fundamental performance compromises between rotary-wing and fixed-wing UAVs. The general solution to address this well-known problem is the design of a platform with some degree of reconfigurable airframes. For critical missions (civilian or military), it is imperative that mechanical complexity is kept to a minimum to help achieve mission success. This work proposes that the tried-and-true radio controlled (RC) aerobatic airplanes can be implemented as basis for fixed-wing UAVs having both speed and vertical takeoff and landing (VTOL) capabilities. These powerful and highly maneuverable airplanes have non-rotatable nacelles, yet capable of deep stall maneuvers. The power requirements for VTOL and level flight of an aerobatic RC airplane are evaluated and they are compared to those of a RC helicopter of similar flying weight. This work provides quantitative validation that commercially available RC aerobatic airplanes can serve as platform to build VTOL capable fixed-wing UAVs that are agile, cost effective, reliable and easy maintenance.
