Improvement of terrain following flight adaptive angle method under small field of view conditions
-
摘要:
针对小视场角条件下适应角法地形跟随飞行时可能出现波浪式前进的现象，分析两种波浪状航迹成因，提出地形信息丢失时的适应角法改进公式。通过设计抑制函数、验证其与高度控制的一致性，并推导指令增益，在无地形数据飞行阶段将地形丢失前的信息与实时高度结合，给出导引指令。利用不同真实地形数据视景仿真验证，该方法可有效解决波浪状航迹问题，避免航迹角与法向过载频繁变化，使飞机以期望安全高度平飞越峰，显著提升地形跟随效果。
Abstract:The causes of two wavy tracks were examined in light of the phenomenon of aircraft moving forward in a wavy mode during terrain following flight with the adaptive angle method under the condition of a small field of view. An improved adaptive angle method formula was also proposed when terrain information is lost. A new suppression function was designed and the command gain was derived for the improved formula which verified its consistency with altitude control. The guidance instruction can be given continuously by combining the information before terrain loss with the real-time altitude in the stage of no terrain information. Through the avoidance of frequent changes in flight path angle and normal overload, the method is confirmed to be effective in addressing the wavy track issue in visual simulation experiments with various real terrain data. This allows the aircraft to fly over the peak at the expected safe height and significantly improves the terrain following effectiveness.
-
Key words:
- terrain following /
- adaptive angle method /
- small field of view /
- terrain data loss /
- wavy track
-
图 2 不同视场角获得的地形图像信息比较
Figure 2. Comparison of terrain image information obtained from different FOV
图 3 不同视场角传统适应角法飞行航迹比较
Figure 3. Comparison of flight tracks by traditional adaptive angle method with different FOV
图 4 波浪式前进现象成因示意图
Figure 4. Schematic diagram of the cause of moving forward in wavy mode
图 5 视野中地形信息临界时的基本角度关系
Figure 5. Basic angular relationships at the criticality of terrain information in the field of view
图 6 跟随山地时2种方案航迹及航迹角比较
Figure 6. Track and flight path angle comparison of two schemes when following mountains
图 7 跟随山地时2种方案法向过载比较
Figure 7. Comparison of normal overload between two schemes when following mountains
图 8 跟随丘陵时两种方案航迹及航迹角比较
Figure 8. Track and flight path angle comparison of two schemes when following hills
图 9 跟随丘陵时两种方案法向过载比较
Figure 9. Comparison of the normal overload between two schemes when following hills
表 1 跟随山地时两种方案飞行效果比较
Table 1. Comparison of flight effect of two schemes when following mountains
地形跟随
方案10 m撞地
概率/%20 m撞地
概率/%30 m撞地
概率/%越峰航迹角
均方根/ （°）越峰高度
误差均方根/ m方案1 5.16 1.92 0.08 4.46 31.59 方案2 0 0 0 0.82 3.78 
下载: 导出CSV
表 2 跟随丘陵时两种方案飞行效果比较
Table 2. Comparison of flight effect of two schemes when following hills
地形跟随
方案10 m撞地
概率/%20 m撞地
概率/%30 m撞地
概率/%越峰航迹角
均方根/ （°）越峰高度
误差均方根/ m方案1 8.38 3.27 0.02 2.22 36.08 方案2 0.36 0 0 0.37 3.60
下载: 导出CSV
-
[1] 姚琼荟. 地形跟踪方法研究[D]. 南京: 南京航空航天大学, 1981: 7-53.YAO Q H. Study on terrain tracking method [D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 1981: 7-53 (in Chinese). [2] 王建平, 沈春林. 地形跟随适应角控制方法[J]. 航空学报, 1992, 13(12): 670-677. doi: 10.3321/j.issn:1000-6893.1992.12.016WANG J P, SHEN C L. The adaptive angle control method of terrain following[J]. Acta Aeronautica et Astronautica Sinica, 1992, 13(12): 670-677 (in Chinese). doi: 10.3321/j.issn:1000-6893.1992.12.016 [3] NELSON D R, BARBER D B, MCLAIN T W, et al. Vector field path following for miniature air vehicles[J]. IEEE Transactions on Robotics, 2007, 23(3): 519-529. doi: 10.1109/TRO.2007.898976 [4] RADMANESH M, KUMAR M, GUENTERT P H, et al. Overview of path-planning and obstacle avoidance algorithms for UAVs: a comparative study[J]. Unmanned systems, 2018, 6(2): 95-118. doi: 10.1142/S2301385018400022 [5] 白晓利, 韩亮. 基于数字地图预处理的低空突防飞行路线规划[J]. 北京航空航天大学学报, 2005, 31(8): 853-857. doi: 10.3969/j.issn.1001-5965.2005.08.006BAI X L, HAN L. Path planning for penetrating aircraft to fly at low altitudes based on technology of digital elevation map[J]. Journal of Beijing University of Aeronautics and Astronautics, 2005, 31(8): 853-857 (in Chinese). doi: 10.3969/j.issn.1001-5965.2005.08.006 [6] EXPERT F, RUFFIER F. Flying over uneven moving terrain based on optic-flow cues without any need for reference frames or accelerometers[J]. Bioinspiration & biomimetics, 2015, 10(2): 026003. [7] RUFFIER F, FRANCESCHINI N. Optic flow regulation in unsteady environments: a tethered MAV achieves terrain following and targeted landing over a moving platform[J]. Journal of Intelligent & Robotic Systems, 2015, 79(2): 275-293. [8] CAMPOS I, NASCIMENTO E, FREITAS G, et al. A height estimation approach for terrain following flights from monocular vision[J]. Sensors, 2016, 16(12): 2071. [9] CHEN Y, LIU H L. Overview of landmarks for autonomous, vision-based landing of unmanned helicopters[J]. IEEE Aerospace and Electronic Systems Magazine, 2016, 31(5): 14-27. [10] LEE D, RYAN T, KIM H J. Autonomous landing of a VTOL UAV on a moving platform using image-based visual servoing[C]// 2012 IEEE International Conference on Robotics and Automation. Piscataway: IEEE Press, 2012: 971-976. [11] ROMERO H, SALAZAR S, LOZANO R. Real-time stabilization of an eight-rotor UAV using optical flow[J]. IEEE Transactions on Robotics, 2009, 25(4): 809-817. doi: 10.1109/TRO.2009.2018972 [12] 刘小明, 陈万春, 邢晓岚, 等. 光流控制地形跟随与自动着陆[J]. 北京航空航天大学学报, 2012, 38(1): 98-105.LIU X M, CHEN W C, XING X L, et al. Terrain following and autonomous landing using optical flow[J]. Journal of Beijing University of Aeronautics and Astronautics, 2012, 38(1): 98-105 (in Chinese). [13] 黄鹏程, 王彪, 唐超颖, 等. 地形跟随飞行中光轴搜索策略[J]. 探测与控制学报, 2022, 44(3): 79-83.HUANG P C, WANG B, TANG C Y, et al. Optical axis search strategies in terrain following flight[J]. Journal of Detection & Control, 2022, 44(3): 79-83 (in Chinese). [14] 范洪达, 马向玲, 叶文. 飞机低空突防航路规划技术[M]. 北京: 国防工业出版社, 2007: 30-32.FAN H D, MA X L, YE W. Route planning technology of aircraft low-altitude penetration[M]. Beijing: National Defense Industry Press, 2007: 30-32 (in Chinese). [15] 乔淼. 基于高差与标准差法的中国地形起伏度研究[J]. 绿色科技, 2020(6): 31-33. doi: 10.3969/j.issn.1674-9944.2020.06.009QIAO M. Research on Chinese terrain undulation based on height difference and standard deviation method[J]. Journal of Green Science and Technology, 2020(6): 31-33 (in Chinese). doi: 10.3969/j.issn.1674-9944.2020.06.009 -
下载:
点击查看大图
计量
- 文章访问数: 294
- HTML全文浏览量: 105
- PDF下载量: 7
- 被引次数: 0
