【ELM预测】基于灰狼算法优化极限学习机预测附matlab代码

1 简介

准确的电池荷电状态(SOC)估计是电动车辆正常工作的基本前提.针对目前电池荷电状态估计时存在的非线性,不平稳等干扰因素的影响,本工作提出了基于灰狼优化算法的极限学习机的锂离子电池SOC估计方法,以提高估计精度并缩短估计时长.传统的极限学习机(ELM)直接随机生成模型参数,并对SOC进行估计,该方法运行速度快且泛化性能好.但极限学习机需要找出最优的隐含层神经元参数才能达到较高的精度.因此,通过灰狼优化算法(GWO)进一步优化模型参数,并通过选择合适的激活函数,弥补了传统极限学习机的不足.

2 部分代码

%___________________________________________________________________%                                                  %%___________________________________________________________________%​% Grey Wolf Optimizerfunction [Alpha_score,Alpha_pos,Convergence_curve]=GWO(SearchAgents_no,Max_iter,lb,ub,dim,fobj)​% initialize alpha, beta, and delta_posAlpha_pos=zeros(1,dim);Alpha_score=inf; %change this to -inf for maximization problems​Beta_pos=zeros(1,dim);Beta_score=inf; %change this to -inf for maximization problems​Delta_pos=zeros(1,dim);Delta_score=inf; %change this to -inf for maximization problems​%Initialize the positions of search agentsPositions=initialization(SearchAgents_no,dim,ub,lb);​Convergence_curve=zeros(1,Max_iter);​l=0;% Loop counter​% Main loopwhile l<Max_iter    for i=1:size(Positions,1)                 % Return back the search agents that go beyond the boundaries of the search space        Flag4ub=Positions(i,:)>ub;        Flag4lb=Positions(i,:)<lb;        Positions(i,:)=(Positions(i,:).*(~(Flag4ub+Flag4lb)))+ub.*Flag4ub+lb.*Flag4lb;                               % Calculate objective function for each search agent        fitness=fobj(Positions(i,:));                % Update Alpha, Beta, and Delta        if fitness<Alpha_score             Alpha_score=fitness; % Update alpha            Alpha_pos=Positions(i,:);        end                if fitness>Alpha_score && fitness<Beta_score             Beta_score=fitness; % Update beta            Beta_pos=Positions(i,:);        end                if fitness>Alpha_score && fitness>Beta_score && fitness<Delta_score             Delta_score=fitness; % Update delta            Delta_pos=Positions(i,:);        end    end            a=2-l*((2)/Max_iter); % a decreases linearly fron 2 to 0        % Update the Position of search agents including omegas    for i=1:size(Positions,1)        for j=1:size(Positions,2)                                        r1=rand(); % r1 is a random number in [0,1]            r2=rand(); % r2 is a random number in [0,1]                        A1=2*a*r1-a; % Equation (3.3)            C1=2*r2; % Equation (3.4)                        D_alpha=abs(C1*Alpha_pos(j)-Positions(i,j)); % Equation (3.5)-part 1            X1=Alpha_pos(j)-A1*D_alpha; % Equation (3.6)-part 1                                   r1=rand();            r2=rand();                        A2=2*a*r1-a; % Equation (3.3)            C2=2*r2; % Equation (3.4)                        D_beta=abs(C2*Beta_pos(j)-Positions(i,j)); % Equation (3.5)-part 2            X2=Beta_pos(j)-A2*D_beta; % Equation (3.6)-part 2                               r1=rand();            r2=rand();                         A3=2*a*r1-a; % Equation (3.3)            C3=2*r2; % Equation (3.4)                        D_delta=abs(C3*Delta_pos(j)-Positions(i,j)); % Equation (3.5)-part 3            X3=Delta_pos(j)-A3*D_delta; % Equation (3.5)-part 3                                     Positions(i,j)=(X1+X2+X3)/3;% Equation (3.7)                    end    end    l=l+1;        Convergence_curve(l)=Alpha_score;end​​​​

3 仿真结果

4 参考文献

[1]王桥, 魏孟, 叶敏,等. 基于灰狼算法优化极限学习机的锂离子电池SOC估计[J]. 储能科学与技术, 2021.

博主简介：擅长智能优化算法、神经网络预测、信号处理、元胞自动机、图像处理、路径规划、无人机等多种领域的Matlab仿真，相关matlab代码问题可私信交流。

部分理论引用网络文献，若有侵权联系博主删除。