Trim Analysis of a Classical Octocopter After Single-Rotor Failure
Trim Analysis of a Classical Octocopter After Single-Rotor Failure
复制标题
经典八轴飞行器单旋翼故障后的配平分析
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
F. Gandhi
中科院分区：
文献类型：
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作者：
Ariel Walter;M. McKay;R. Niemiec;F. Gandhi
本文研究了单旋翼直升机在悬停和前飞状态下的性能。飞机模型采用叶素理论和有限状态动态入流模型来确定旋翼气动力（推力、阻力和侧力）和力矩（滚转力矩、俯仰力矩和扭矩）。在两种飞行条件下都考虑了各种旋翼的故障，并根据为飞机定义的多旋翼控制，了解了飞机故障后如何配平。在悬停状态下，基线旋翼直升机在所有旋翼以相同转速运行的情况下进行配平。当转子发生故障时，存在配平解决方案，其利用飞机的原始无反作用控制来驱动故障转子的指令推力为零。所使用的无反作用控制的组合根据故障转子的位置而变化。故障后，主要的和无反作用的多旋翼控制重新定义为每个转子的原始多旋翼控制。在前飞中，旋翼故障的恢复方式与悬停情况类似，需要额外的输入来补偿悬停时不存在的旋翼桨毂力矩和面内力。总的来说，在10 m/s的悬停和前飞中，对于任何单个旋翼故障都存在配平解决方案。在悬停状态下，旋翼故障需要额外增加10.7%的配平功率，在前飞状态下，根据发生故障的旋翼，该损失范围在7.7%和13%之间。
The performance of an octocopter with single rotor failure is examined in hover and forward flight conditions. The aircraft model uses blade element theory coupled with a finite-state dynamic inflow model to determine rotor aerodynamic forces (thrust, drag, and side-force) and moments (rolling moment, pitching moment, and torque). Failure of various rotors is considered in both flight conditions and an understanding is developed of how the aircraft trims post-failure in terms of multirotor controls defined for the aircraft. In hover, the baseline octocopter trims with all rotors operating at the same rotational speed. When a rotor fails, trim solutions exist that utilize the original reactionless controls of the aircraft to drive the commanded thrust of the failed rotor to zero. The combination of reactionless controls used varies depending on the position of the failed rotor. Post-failure, the primary and reactionless multirotor controls are redefined for each rotor in terms of the original multirotor controls. In forward flight, rotor failure is recovered in a similar manner to the hover case, with additional inputs required to compensate for the rotor hub moments and in-plane forces that were not present in hover. Overall, trim solutions exist for any single rotor failure in both hover and forward flight at 10 m/s. In hover, rotor failure requires an additional 10.7% increase in power to trim, in forward flight this penalty is found to range between 7.7 and 13% depending on the rotor that has failed.