西北工业大学学报
西北工業大學學報
서북공업대학학보
JOURNAL OF NORTHWESTERN POLYTECHNICAL UNIVERSITY
2013年
4期
505-510
,共6页
徐明兴%祝小平%周洲%肖伟%冯引安
徐明興%祝小平%週洲%肖偉%馮引安
서명흥%축소평%주주%초위%풍인안
太阳能无人机%控制分配%伪逆法%不动点法%动态分配
太暘能無人機%控製分配%偽逆法%不動點法%動態分配
태양능무인궤%공제분배%위역법%불동점법%동태분배
constrained optimization%energy efficiency%errors%function%MATLAB,propellers%unmanned aerial vehicles (UAV)%dynamic characteristic%fixed point method%pseudo-inverse method%solar-powered UAV%thrust allocation
太阳能无人机的设计需以能量为核心,太阳能无人机多采用分布式推进系统,对推力分配进行优化可以有效提高螺旋桨效率进而提高能源利用率。在推力到桨效率的函数为凸函数的情况下,螺旋桨效率之和最大分配问题可以近似转化为拉力二范数最小分配问题,使用伪逆法解决了拉力二范数最小分配问题。将伪指令vd 的误差最小作为优化目标之一考虑,形成混合优化目标,用不动点法求解了混合目标分配问题。螺旋桨的衰减滞后特性会增大伪指令误差,使用动态增益对螺旋桨动态特性进行补偿。对比数字仿真结果,不动点法相比伪逆法在降低了伪指令误差的同时,可以有效兼顾推进系统效率最高的目标;动态增益补偿可以有效削弱螺旋桨动态特性对整个推力分配系统造成的不利影响。
太暘能無人機的設計需以能量為覈心,太暘能無人機多採用分佈式推進繫統,對推力分配進行優化可以有效提高螺鏇槳效率進而提高能源利用率。在推力到槳效率的函數為凸函數的情況下,螺鏇槳效率之和最大分配問題可以近似轉化為拉力二範數最小分配問題,使用偽逆法解決瞭拉力二範數最小分配問題。將偽指令vd 的誤差最小作為優化目標之一攷慮,形成混閤優化目標,用不動點法求解瞭混閤目標分配問題。螺鏇槳的衰減滯後特性會增大偽指令誤差,使用動態增益對螺鏇槳動態特性進行補償。對比數字倣真結果,不動點法相比偽逆法在降低瞭偽指令誤差的同時,可以有效兼顧推進繫統效率最高的目標;動態增益補償可以有效削弱螺鏇槳動態特性對整箇推力分配繫統造成的不利影響。
태양능무인궤적설계수이능량위핵심,태양능무인궤다채용분포식추진계통,대추력분배진행우화가이유효제고라선장효솔진이제고능원이용솔。재추력도장효솔적함수위철함수적정황하,라선장효솔지화최대분배문제가이근사전화위랍력이범수최소분배문제,사용위역법해결료랍력이범수최소분배문제。장위지령vd 적오차최소작위우화목표지일고필,형성혼합우화목표,용불동점법구해료혼합목표분배문제。라선장적쇠감체후특성회증대위지령오차,사용동태증익대라선장동태특성진행보상。대비수자방진결과,불동점법상비위역법재강저료위지령오차적동시,가이유효겸고추진계통효솔최고적목표;동태증익보상가이유효삭약라선장동태특성대정개추력분배계통조성적불리영향。
Designing a solar-powered unmanned aerial vehicle ( UAV) should center on its energy .As the majority of solar-powered UAVs have distributive propulsion systems , the optimization of their thrust allocation may effective-ly enhance the efficiency of the propeller and energy utilization .When the function from thrust to propeller efficien-cy is a convex one , the maximum allocation of the sum of propeller efficiency can be approximately converted into the two-norm minimum allocation of thrust , which can be achieved with the pseudo-inverse method .Taking the minimization of the error of the pseudo-instruction as one of optimization objectives , we obtain the mixed optimiza-tion objective .Then we use the fixed point method to achieve the mixed optimization objective .As the attenuation and hysteresis of the propeller may increase the error of the pseudo-instruction, we use the dynamic gain to compen-sate for the dynamic characteristics of the propeller .Finally we simulate the thrust allocation of the solar-powered UAV and the compensation for the propeller ’ s dynamic characteristics .The simulation results , given in Tables 1 through 4 and Figs.4,5,7 and 8,and their comparison show preliminarily that:(1)compared with the pseudo-in-verse method , the fixed point method can not only reduce the error of pseudo-instruction but also effectively achieve maximum energy efficiency of the propulsion system;(2)the dynamic gain compensation can effectively reduce the adverse influence of the propeller ’ s dynamic characteristics on the thrust allocation .