楊潔 程曉健 穆彥斌
關鍵詞: 海戰(zhàn)場; 電磁態(tài)勢; 神經(jīng)網(wǎng)絡; 粒子群算法; 模擬退火法; 遺傳算法
中圖分類號: TN911.1?34; TP311.54 ? ? ? ? ? ? ? ? ? 文獻標識碼: A ? ? ? ? ? ? ? ?文章編號: 1004?373X(2019)03?0001?05
Abstract: A sea battlefield electromagnetic state prediction method based on improved particle swarm optimization (PSO)algorithm optimizing radial basis function (RBF) neural network is proposed to solve the prediction problem of sea battlefield electromagnetic state. The adaptive inertia weight, simulated annealing method and genetic algorithm are used in the method to improve the conventional PSO algorithm, and its search accuracy and speed. The improved PSO algorithm is used to optimize the parameters of RBF neural network, which can improve the learning efficiency and prediction accuracy of the network. The simulation prediction is carried out for the non?linear mapping relationship between the electromagnetic state values of the sea battlefield. The experimental results show that the method can improve the prediction accuracy of the sea battlefield electromagnetic state effectively, and has strong applicability.
Keywords: sea battlefield; electromagnetic state; neural network; particle swarm optimization algorithm; simulated annealing method; genetic algorithm
海戰(zhàn)場電磁態(tài)勢感知是一種通過對海戰(zhàn)場電磁環(huán)境要素的獲取、理解、預測而形成易于指揮員準確認識海戰(zhàn)場電磁環(huán)境并能輔助其決策的方法[1]?,F(xiàn)有的態(tài)勢評估方法大多只能提供給指揮員過去和當前的海戰(zhàn)場電磁態(tài)勢情況,無法預測下一階段態(tài)勢變化情況,使得己方在未來戰(zhàn)爭中處于被動狀態(tài)。因此,海戰(zhàn)場電磁態(tài)勢預測成為未來戰(zhàn)場中亟待解決的問題。
目前國內(nèi)外對于海戰(zhàn)場電磁態(tài)勢的研究主要集中在電磁環(huán)境可視化[2]、電磁環(huán)境復雜度評估[3]、輻射源識別[4]等方面,缺乏生成系統(tǒng)海戰(zhàn)場電磁態(tài)勢的技術(shù)手段。文獻[1]提出了海戰(zhàn)場電磁感知的基本模型,但并未對態(tài)勢理解域中的態(tài)勢預測作進一步分析。文獻[5]將博弈論應用于戰(zhàn)場通信對抗態(tài)勢預測中,但預測結(jié)果誤差較大。徑向基函數(shù)(Radial Basis Function,RBF)神經(jīng)網(wǎng)絡具有收斂速度快、結(jié)構(gòu)簡單、非線性映射能力好等特點[6],已廣泛應用于模式識別[7]、網(wǎng)絡安全態(tài)勢預測[8]等領域。同時,為了提高RBF神經(jīng)網(wǎng)絡性能,國內(nèi)學者利用粒子群算法(Particle Swarm Optimization,PSO)的搜索能力和RBF神經(jīng)網(wǎng)絡的非線性映射能力,提出改進粒子群算法優(yōu)化RBF神經(jīng)網(wǎng)絡預測模型[9]。
為了準確把握海戰(zhàn)場電磁發(fā)展態(tài)勢,在已有研究成果的基礎上,提出一種基于改進PSO算法優(yōu)化RBF神經(jīng)網(wǎng)絡的海戰(zhàn)場電磁態(tài)勢預測方法。該方法首先對海戰(zhàn)場電磁態(tài)勢要素進行分析,繼而獲得海戰(zhàn)場電磁整體態(tài)勢值,然后采用改進的粒子群算法優(yōu)化RBF神經(jīng)網(wǎng)絡,尋找海戰(zhàn)場電磁值之間的非線性映射關系,對未來時刻海戰(zhàn)場電磁態(tài)勢進行預測。
海戰(zhàn)場電磁態(tài)勢值是在對海戰(zhàn)場電磁環(huán)境物理特性和電磁環(huán)境中電子設備用頻效能分析的基礎上,通過一定的數(shù)學模型進行計算,將人們不易理解的海戰(zhàn)場電磁環(huán)境和戰(zhàn)場態(tài)勢信息歸并融合成人們?nèi)菀桌斫夂徒邮艿臄?shù)值。這些數(shù)值能夠客觀實時反映海戰(zhàn)場電磁域中戰(zhàn)場態(tài)勢情況,其大小取決于海戰(zhàn)場電磁態(tài)勢要素。針對電磁環(huán)境特點,將電磁態(tài)勢劃分為一般態(tài)勢和相對態(tài)勢兩部分。一般態(tài)勢如海戰(zhàn)場區(qū)域內(nèi)電磁信號的空間覆蓋率、時間占用率、頻段占用率、平均功率密度譜等[10];相對態(tài)勢如探測雷達的發(fā)現(xiàn)目標概率和最大探測距離,制導系統(tǒng)對目標的跟蹤精度和制導概率,通信系統(tǒng)之間的誤信率、誤碼率以及電子設備和系統(tǒng)在電子干擾和反輻射攻擊中的生存能力等[11]。電磁態(tài)勢評估指標體系如圖1所示。
同時為了驗證所提算法的優(yōu)越性,采用IMPSO?RBF預測模型[9]及SACPSO?RBF預測模型[12]進行相同的實驗。網(wǎng)絡訓練過程中最優(yōu)適應度值曲線如圖3所示,預測結(jié)果如圖4所示。
由圖3所示,盡管三種預測模型在網(wǎng)絡訓練過程中最佳適應度值都可以很快收斂到最小值,但相對于其他兩種預測模型,該預測模型可以更快找到態(tài)勢值之間的非線性映射關系。其原因在于本文方法能夠根據(jù)粒子群中粒子的適應度值自適應賦予其移動速度權(quán)重,能更快地尋找到最佳粒子位置,因此,加快了優(yōu)化后的RBF網(wǎng)絡預測模型的收斂速度。
由圖4中的預測曲線可以看出,三種預測模型都取得了一定的預測效果。如圖5所示,本文方法的預測效果更好,更符合真實電磁態(tài)勢變化趨勢。這是因為本文方法采用模擬退火法避免了粒子群算法在搜索過程中陷入局部極小值的問題,并采用遺傳算法中的交叉、變異操作提高了種群多樣性,提高了PSO算法在全局最優(yōu)解的搜索能力。
為了進一步體現(xiàn)本文方法的優(yōu)越性,分別計算了三種預測模型的均方根誤差(RMSE)、平均相對誤差(MAPE),如表1所示。
從表1中可以看出,相對于IMPSO?RBF預測模型及SACPSO?RBF預測模型,本文預測模型得到的電磁態(tài)勢值的均方根誤差(RMSE),平均相對誤差(MAPE)均明顯降低。
針對海戰(zhàn)場電磁態(tài)勢的預測問題,本文提出一種基于改進PSO優(yōu)化RBF神經(jīng)網(wǎng)絡的海戰(zhàn)場電磁態(tài)勢預測方法。通過對海戰(zhàn)場電磁態(tài)勢要素的分析,生成能客觀反映海戰(zhàn)場電磁域的整體態(tài)勢值,利用改進PSO算法優(yōu)化RBF神經(jīng)網(wǎng)絡參數(shù),并與其他預測模型的測試結(jié)果對比,該方法可以取得更高的預測精度,在海戰(zhàn)場電磁態(tài)勢預測領域具有一定的應用價值。
參考文獻
[1] 周倜,王小非,陳煒.海戰(zhàn)場電磁態(tài)勢感知模型[J].火力與指揮控制,2013,38(8):1?5.
ZHOU Ti, WANG Xiaofei, CHEN Wei. Electromagnetic situation perception model for sea battlefield [J]. Fire control & command control, 2013, 38(8): 1?5.
[2] TANG D, HAN H, YUAN K. Research on the essence and visualization description method of battlefield electromagnetic environment [J]. Ordnance industry automation, 2014(11): 57?59.
[3] WANG F, HAN H, WANG J, et al. The complexity evaluation method of electromagnetic environment based on statistical characteristics analysis [J]. Applied mechanics & materials, 2013, 321/324: 779?784.
[4] 陳求,戎華,譚亮亮.基于最小二乘法的雷達輻射源精確識別指標權(quán)重確定方法[J].艦船電子對抗,2016,39(4):52?55.
CHEN Qiu, RONG Hua, TAN Liangliang. A method for determining precise identification indexes of radar emitters based on least squares [J]. Shipboard electronic countermeasure, 2016, 39(4): 52?55.
[5] 馮德俊,朱江,李方偉.戰(zhàn)場電磁態(tài)勢感知關鍵技術(shù)研究[J].數(shù)字通信,2013,40(5):20?23.
FENG Dejun, ZHU Jiang, LI Fangwei. Research on key technologies of electromagnetic situation sensing in battlefield [J]. Digital communication, 2013, 40(5): 20?23.
[6] HAN H G, QIAO J F. Prediction of activated sludge bulking based on a self?organizing RBF neural network [J]. Journal of process control, 2012, 22(6): 1103?1112.
[7] 杜剛,何朔,于海鵬.基于徑向基函數(shù)神經(jīng)網(wǎng)絡的空間碎片撞擊模式識別研究[J].航天器環(huán)境工程,2015,32(4):357?360.
DU Gang, HE Shuo, YU Haipeng. Research on pattern recognition of space debris impact based on radial basis function neural network [J]. Spacecraft environment engineering, 2015, 32(4): 357?360.
[8] 李方偉,鄭波,朱江,等.一種基于AC?RBF神經(jīng)網(wǎng)絡的網(wǎng)絡安全態(tài)勢預測方法[J].重慶郵電大學學報(自然科學版),2014,26(5):576?581.
LI Fangwei, ZHENG Bo, ZHU Jiang, et al. An approach to forecast the network security situation based on AC?RBF neural network [J]. Journal of Chongqing University of Posts and Telecommunications (natural science edition), 2014, 26(5): 576?581.
[9] 夏軒,許偉明.改進的粒子群算法對RBF神經(jīng)網(wǎng)絡的優(yōu)化[J].計算機工程與應用,2012,48(5):37?40.
XIA Xuan, XU Weiming. Optimization of RBF neural network based on improved particle swarm optimization [J]. Journal of computer engineering and applications, 2012, 48(5): 37?40.
[10] CAI X F, SONG J S. Analysis of complexity in battlefield electromagnetic environment [C]// 2009 IEEE Conference on Industrial Electronics and Applications. Xian, China: IEEE, 2009: 2440?2442.
[11] 高波,馬向玲,隋江波.海戰(zhàn)復雜電磁環(huán)境分析[J].火力與指揮控制,2013,38(3):1?4.
GAO Bo, MA Xiangling, SUI Jiangbo. Analysis of complex electromagnetic environment in sea battle [J]. Fire control & command control, 2013, 38(3): 1?4.
[12] 張義,田愛奎,韓士元.一種自適應的混沌粒子群優(yōu)化RBF神經(jīng)網(wǎng)絡算法[J].重慶理工大學學報,2015,29(11):126?130.
ZHANG Yi, TIAN Aikui, HAN Shiyuan. An adaptive RBF neural network algorithm based on chaotic particle swarm optimization [J]. Journal of Chongqing Institute of Technology, 2015, 29(11): 126?130.
[13] CHEN G C, YU J S. Particle swarm optimization algorithm [J]. Information & control, 2005, 306: 1369?1372.
[14] 董俊,洪麗娜,汪連棟,等.多輻射平臺運動區(qū)域電磁環(huán)境預測方法[J].現(xiàn)代防御技術(shù),2016,44(2):190?196.
DONG Jun, HONG Lina, WANG Liandong, et al. An electromagnetic environment prediction method in multi?radiation platform motion area [J]. Modern defence technology, 2016, 44(2): 190?196.