function [Kp,Ti,Td,key,lb]=pid_br_tune(key1,key2,vars)  
key=0; Kp=[]; Ti=[]; Td=[]; lb=[];
K=vars(1); L=vars(2); T=vars(3);id=vars(4);
switch key1
    case 1
        switch key2
            case 5
                if  L/T<0.1
                    Lmda=1;
                    Kp=(T+0.5*L)/(K*(Lmda+L));Ti=T+0.5*L;
                    key=3;lb=0.1;
                elseif  0.1<=L/T&L/T<=1
                    Lmda=1;
                    Kp=(T+0.5*L)/(K*(Lmda+L));Ti=T+0.5*L;
                    key=1;
                elseif    1<L/T&L/T<=10
                    lmda=1-0.5*lg(L/T);
                    Kp=(T+0.5*L)/(K*(Lmda+L));Ti=T+0.5*L;
                    key=1;
                else 
                    lmda=1-0.5*lg(L/T);
                    Kp=(T+0.5*L)/(K*(Lmda+L));Ti=T+0.5*L;
                    key=2;lb=10;
                end
        end
    case 2
        switch key2
            case 5
                if L/T<0.1
                    Kp=(T+0.5*L)/(0.35*K*L);Ti=T+0.5*L;Td=T*L/(2*T+L);
                    key=3;lb=0.1;
                elseif L/T>10
                    Kp=(T+0.5*L)/(0.35*K*L);Ti=T+0.5*L;Td=T*L/(2*T+L);
                    key=2;lb=10;
                else
                    Kp=(T+0.5*L)/(0.35*K*L);Ti=T+0.5*L;Td=T*L/(2*T+L);
                    key=1;
                end
        end
end