为了提高微型飞行器(MAV)无线视频传输的质量、扩大传输距离,设计并实现了一种基于3G WCDMA无线网络的机载视频传输系统。采用TI公司的达芬奇处理器TMS320DM355作为核心处理器,给出了总体设计方案和硬件结构,并阐述了采用PPP协议拨号接...为了提高微型飞行器(MAV)无线视频传输的质量、扩大传输距离,设计并实现了一种基于3G WCDMA无线网络的机载视频传输系统。采用TI公司的达芬奇处理器TMS320DM355作为核心处理器,给出了总体设计方案和硬件结构,并阐述了采用PPP协议拨号接入WCDMA网络的方法。采用嵌入式Linux操作系统作为软件开发平台,分析并设计了基于V4L2(Video For Linux Two)驱动的视频采集模块。通过调用TI提供的编解码引擎API,实现了视频MPEG-4压缩编码处理。针对视频传输的实时性要求,采用了实时传输协议RTP和实时传输控制协议RTCP,重点阐述了MPEG-4视频的RTP封包策略,并基于JRTPLIB库文件实现了视频的实时传输功能。实验结果表明,该系统可以满足视频清晰、实时的传输要求。展开更多
A simple yet efficient tracking framework is proposed for real-time multi-object tracking with micro aerial vehicles(MAVs). It's basic missions for MAVs to detect specific targets and then track them automatically...A simple yet efficient tracking framework is proposed for real-time multi-object tracking with micro aerial vehicles(MAVs). It's basic missions for MAVs to detect specific targets and then track them automatically. In our method, candidate regions are generated using the salient detection in each frame and then classified by an eural network. A kernelized correlation filter(KCF) is employed to track each target until it disappears or the peak-sidelobe ratio is lower than a threshold. Besides, we define the birth and death of each tracker for the targets. The tracker is recycled if its target disappears and can be assigned to a new target. The algorithm is evaluated on the PAFISS and UAV123 datasets. The results show a good performance on both the tracking accuracy and speed.展开更多
This paper reports the design, construction, and operation of NWPU20 Micro Air Vehicle (MAV), which is the smallest that has, up to now, been developed in PR China. The miniaturization level in PR China makes smaller ...This paper reports the design, construction, and operation of NWPU20 Micro Air Vehicle (MAV), which is the smallest that has, up to now, been developed in PR China. The miniaturization level in PR China makes smaller MAV, in our opinion, not possible to implement. The NWPU20 is a 20-centimeter span, battery powered, fixed-wing aircraft with an off-the-shelf color video camera that can transmit live video back to the ground station. The on-board electronic subsystems are smallest and lightest among the commercial products, including an 8-gram wireless video camera, an 8-gram receiver, a 5-gram electronic speed controller (ESC), two 4.5-gram fully proportional radio frequency control servos, and the total mass of NWPU20 is less than 80 grams. An experimental model was fabricated and tested in the Low Turbulent Flow Wind Tunnel (LTFWT) at Northwestern Polytechnical University (NWPU) to research low Reynolds number flow characteristics of the NWPU20. The result of the wind tunnel test shows that stall angle of attack of NWPU20 can reach 30°, which is higher than that of the general aircrafts, and the maximum lift-to-drag ratio of NWPU20 can nearly reach 6 at the angle of attack of 10°, which can satisfy design requirements of the NWPU20. A small-sized propulsion/torque testing system was developed to measure and analyze the propulsion and torque performances of the motor-propeller combination used in the NWPU20. A center of gravity (c.g.) testing apparatus was developed and used to adjust the c.g. of the NWPU20 so that it has good longitudinal static stability and control. The NWPU20 prototype has undergone successfully flight tests many times; it flies at 32 kilometers per hour, with an endurance of 15 minutes, and a maximum communications range of 300 meters. With the color video camera, NWPU20 successfully transmits real-time video back to the ground station. The success of NWPU20 proves preliminarily that 20-centimeter span micro air vehicle is feasible and usable.展开更多
The overall hardware construction of autopilot within micro aerial vehicle is presented. The boot process of VxWorks real time operating system as well as the conception and function of board support package （BSP） i...The overall hardware construction of autopilot within micro aerial vehicle is presented. The boot process of VxWorks real time operating system as well as the conception and function of board support package （BSP） is described. And the transplantation process of the VxWroks operat ing system into the hardware platform mentioned above is highlighted. It is shown from the final re sults that VxWorks has high stability and real time performance, ensuring accurate flight control and a smooth flight of the micro aerial vehicle.展开更多
A low-power complementary metal oxide semiconductor（CMOS） operational amplifier （op-amp） for real-time signal processing of micro air vehicle （MAV） is designed in this paper.Traditional folded cascode architectu...A low-power complementary metal oxide semiconductor（CMOS） operational amplifier （op-amp） for real-time signal processing of micro air vehicle （MAV） is designed in this paper.Traditional folded cascode architecture with positive channel metal oxide semiconductor（PMOS） differential input transistors and sub-threshold technology are applied under the low supply voltage.Simulation results show that this amplifier has significantly low power,while maintaining almost the same gain,bandwidth and other key performances.The power required is only 0.12 mW,which is applicable to low-power and low-voltage real-time signal acquisition and processing system.展开更多
The Magnus effect is well known phenomena for producing high lift values from spinning symmetrical geometries such as cylinders, spheres, or disks. But, the Magnus force may also be produced by treadmill motion of aer...The Magnus effect is well known phenomena for producing high lift values from spinning symmetrical geometries such as cylinders, spheres, or disks. But, the Magnus force may also be produced by treadmill motion of aerodynamic bodies. To accomplish this, the skin of aerodynamic bodies may circulate with a constant circumferential speed. Here, a novel wing with treadmill motion of skin is introduced which may generate lift at zero air speeds. The new wing may lead to micro aerial vehicle configurations for vertical take-off or landing. To prove the concept, the NACA0015 aerofoil section with circulating skin is computationally investigated. Two cases of stationary air and moving air are studied. It is observed that lift can be generated in stationary air although drag force is also high. For moving air, the lift and drag forces may be adopted between the incidence angles 20° to 25° where lift can posses high values and drag can remain moderate.展开更多
文摘为了提高微型飞行器(MAV)无线视频传输的质量、扩大传输距离,设计并实现了一种基于3G WCDMA无线网络的机载视频传输系统。采用TI公司的达芬奇处理器TMS320DM355作为核心处理器,给出了总体设计方案和硬件结构,并阐述了采用PPP协议拨号接入WCDMA网络的方法。采用嵌入式Linux操作系统作为软件开发平台,分析并设计了基于V4L2(Video For Linux Two)驱动的视频采集模块。通过调用TI提供的编解码引擎API,实现了视频MPEG-4压缩编码处理。针对视频传输的实时性要求,采用了实时传输协议RTP和实时传输控制协议RTCP,重点阐述了MPEG-4视频的RTP封包策略,并基于JRTPLIB库文件实现了视频的实时传输功能。实验结果表明,该系统可以满足视频清晰、实时的传输要求。
基金Supported by the National Natural Science Foundation of China(6160303040,61433003)Yunnan Applied Basic Research Project of China(201701CF00037)Yunnan Provincial Science and Technology Department Key Research Program(Engineering)(2018BA070)
文摘A simple yet efficient tracking framework is proposed for real-time multi-object tracking with micro aerial vehicles(MAVs). It's basic missions for MAVs to detect specific targets and then track them automatically. In our method, candidate regions are generated using the salient detection in each frame and then classified by an eural network. A kernelized correlation filter(KCF) is employed to track each target until it disappears or the peak-sidelobe ratio is lower than a threshold. Besides, we define the birth and death of each tracker for the targets. The tracker is recycled if its target disappears and can be assigned to a new target. The algorithm is evaluated on the PAFISS and UAV123 datasets. The results show a good performance on both the tracking accuracy and speed.
文摘This paper reports the design, construction, and operation of NWPU20 Micro Air Vehicle (MAV), which is the smallest that has, up to now, been developed in PR China. The miniaturization level in PR China makes smaller MAV, in our opinion, not possible to implement. The NWPU20 is a 20-centimeter span, battery powered, fixed-wing aircraft with an off-the-shelf color video camera that can transmit live video back to the ground station. The on-board electronic subsystems are smallest and lightest among the commercial products, including an 8-gram wireless video camera, an 8-gram receiver, a 5-gram electronic speed controller (ESC), two 4.5-gram fully proportional radio frequency control servos, and the total mass of NWPU20 is less than 80 grams. An experimental model was fabricated and tested in the Low Turbulent Flow Wind Tunnel (LTFWT) at Northwestern Polytechnical University (NWPU) to research low Reynolds number flow characteristics of the NWPU20. The result of the wind tunnel test shows that stall angle of attack of NWPU20 can reach 30°, which is higher than that of the general aircrafts, and the maximum lift-to-drag ratio of NWPU20 can nearly reach 6 at the angle of attack of 10°, which can satisfy design requirements of the NWPU20. A small-sized propulsion/torque testing system was developed to measure and analyze the propulsion and torque performances of the motor-propeller combination used in the NWPU20. A center of gravity (c.g.) testing apparatus was developed and used to adjust the c.g. of the NWPU20 so that it has good longitudinal static stability and control. The NWPU20 prototype has undergone successfully flight tests many times; it flies at 32 kilometers per hour, with an endurance of 15 minutes, and a maximum communications range of 300 meters. With the color video camera, NWPU20 successfully transmits real-time video back to the ground station. The success of NWPU20 proves preliminarily that 20-centimeter span micro air vehicle is feasible and usable.
基金Supported by the Ministerial Level Foundation(A222006450)
文摘The overall hardware construction of autopilot within micro aerial vehicle is presented. The boot process of VxWorks real time operating system as well as the conception and function of board support package （BSP） is described. And the transplantation process of the VxWroks operat ing system into the hardware platform mentioned above is highlighted. It is shown from the final re sults that VxWorks has high stability and real time performance, ensuring accurate flight control and a smooth flight of the micro aerial vehicle.
基金Sponsored by the National Natural Science Foundation of China (60843005)the Basic Research Foundation of Beijing Institute of Technology(20070142018)
文摘A low-power complementary metal oxide semiconductor（CMOS） operational amplifier （op-amp） for real-time signal processing of micro air vehicle （MAV） is designed in this paper.Traditional folded cascode architecture with positive channel metal oxide semiconductor（PMOS） differential input transistors and sub-threshold technology are applied under the low supply voltage.Simulation results show that this amplifier has significantly low power,while maintaining almost the same gain,bandwidth and other key performances.The power required is only 0.12 mW,which is applicable to low-power and low-voltage real-time signal acquisition and processing system.
文摘The Magnus effect is well known phenomena for producing high lift values from spinning symmetrical geometries such as cylinders, spheres, or disks. But, the Magnus force may also be produced by treadmill motion of aerodynamic bodies. To accomplish this, the skin of aerodynamic bodies may circulate with a constant circumferential speed. Here, a novel wing with treadmill motion of skin is introduced which may generate lift at zero air speeds. The new wing may lead to micro aerial vehicle configurations for vertical take-off or landing. To prove the concept, the NACA0015 aerofoil section with circulating skin is computationally investigated. Two cases of stationary air and moving air are studied. It is observed that lift can be generated in stationary air although drag force is also high. For moving air, the lift and drag forces may be adopted between the incidence angles 20° to 25° where lift can posses high values and drag can remain moderate.
