This paper models the Mars UAV formation exploring the surface of Mars,and then the formation obstacle avoidance is brought up with the assumptions of the Mars circumstance and the UAVs.Based on their specialty,constr...This paper models the Mars UAV formation exploring the surface of Mars,and then the formation obstacle avoidance is brought up with the assumptions of the Mars circumstance and the UAVs.Based on their specialty,constrained Delaunay triangulation,Yen-K shortest path algorithm,the collaborative function,and the improved pigeon-inspired optimization(PIO)algorithm are integrated to solve the obstacle avoidance for the formation.Since the steering maneuver costs much energy and increases instabilities vulnerable in extraterrestrial exploration,the paper focuses on the route smoothness problem.The PIO is improved to be suitable for smooth routes and is compatible with other PIO variants.The simulation results show that the sum of the steering angle,namely the performance index,is e®ectively reduced and satises the obstacle avoidance requirements for Mars UAV formation.展开更多
This paper reports the results of the aerodynamic deformation measurements of the meter-scale, entire shape, actual UAV in the wind tunnel using a video grammetry technique. The measured airplane was the airplane for ...This paper reports the results of the aerodynamic deformation measurements of the meter-scale, entire shape, actual UAV in the wind tunnel using a video grammetry technique. The measured airplane was the airplane for Mars exploration being developed by Japan Aerospace Exploration Agency (JAXA) and Japanese universities. Its main wing span length was 2.4 m. The video grammetry measurement was performed using VICON’s system. Retroactive markers and stickers were put on the airplane. JAXA’s 6.5 m × 5.5 m Low-Speed Wind Tunnel was used. The airplane was mounted on the strut support with pitch-free or pitch-locked conditions. The deformations of the main wing bending, the main wing twisting, the tail boom bending, and the elevator deflection angle change were revealed quantitatively. The bending stiffness of a main wing spar that was designed as a safety factor of 2.8 at load factor of 5 was sufficient. The main wing spar was located around a center of pressure of an airfoil and it showed enough stiffness for twisting at nominal condition. The effects of the main wing bending and twisting, and the tail boom bending on the aerodynamic performance were estimated but they were in an acceptable range from the standpoint of the controllability of the aerodynamic performance using control surfaces. Even though the servo motor was located near the elevator and the linkage between the servo motor and the elevator was short, the measured elevator deflection angle was at most 4% smaller than the angle at no-wind condition. The obtained results and presented method are useful for control, flight data analysis, and design of lightweight airplanes.展开更多
文摘This paper models the Mars UAV formation exploring the surface of Mars,and then the formation obstacle avoidance is brought up with the assumptions of the Mars circumstance and the UAVs.Based on their specialty,constrained Delaunay triangulation,Yen-K shortest path algorithm,the collaborative function,and the improved pigeon-inspired optimization(PIO)algorithm are integrated to solve the obstacle avoidance for the formation.Since the steering maneuver costs much energy and increases instabilities vulnerable in extraterrestrial exploration,the paper focuses on the route smoothness problem.The PIO is improved to be suitable for smooth routes and is compatible with other PIO variants.The simulation results show that the sum of the steering angle,namely the performance index,is e®ectively reduced and satises the obstacle avoidance requirements for Mars UAV formation.
文摘深空探测巡视任务中巡视器的高精度定位对于巡视器的自身安全与持续运行至关重要。巡视器定位主要包括相对定位和绝对定位两种方式,其中绝对定位方法主要是利用轨道器/着陆器的数据为基准确定巡视器在全局坐标系下的位置。美国Mars 2020任务携带的机智号无人机在火星环境下完成了飞行验证,它能够获得高分辨率的火星表面影像,从而为火星巡视器绝对定位提供了新思路。据此,本文提出了一种卫星-无人机-巡视器影像协同的多分辨率影像匹配绝对定位框架。首先,利用运动恢复结构(structure from motion, SFM)方法对无人机影像进行三维重建,获取局部高分辨率三维地图;然后,开展巡视器影像与无人机影像的多视角匹配,并基于匹配结果利用后方交会实现巡视器在无人机局部地图中的高精度定位;最后,通过局部无人机影像与卫星影像的配准,实现卫星影像全局坐标系下的巡视器绝对定位。为验证本文方法的可行性,开展了巡视器定位仿真试验,试验结果验证了本文方法的可行性,能够为后续我国开展类似工程任务提供参考。
文摘This paper reports the results of the aerodynamic deformation measurements of the meter-scale, entire shape, actual UAV in the wind tunnel using a video grammetry technique. The measured airplane was the airplane for Mars exploration being developed by Japan Aerospace Exploration Agency (JAXA) and Japanese universities. Its main wing span length was 2.4 m. The video grammetry measurement was performed using VICON’s system. Retroactive markers and stickers were put on the airplane. JAXA’s 6.5 m × 5.5 m Low-Speed Wind Tunnel was used. The airplane was mounted on the strut support with pitch-free or pitch-locked conditions. The deformations of the main wing bending, the main wing twisting, the tail boom bending, and the elevator deflection angle change were revealed quantitatively. The bending stiffness of a main wing spar that was designed as a safety factor of 2.8 at load factor of 5 was sufficient. The main wing spar was located around a center of pressure of an airfoil and it showed enough stiffness for twisting at nominal condition. The effects of the main wing bending and twisting, and the tail boom bending on the aerodynamic performance were estimated but they were in an acceptable range from the standpoint of the controllability of the aerodynamic performance using control surfaces. Even though the servo motor was located near the elevator and the linkage between the servo motor and the elevator was short, the measured elevator deflection angle was at most 4% smaller than the angle at no-wind condition. The obtained results and presented method are useful for control, flight data analysis, and design of lightweight airplanes.
