function [Kp,Ti,Td,key,lb]=pid_ro_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 3
                switch id
                      case 1
                            Kp=0.758*(T/L)^0.861/K;Ti=T/(1.020-0.323*L/T);
                      case 2
                            Kp=0.586*(T/L)^0.916/K;Ti=T/(1.030-0.165*L/T);
                end
                if L/T>1
                    key=2;lb=1;
                elseif L/T<0.1
                    key=3;lb=0.1;
                else
                    key=1;
                end
        end
    case 2
        switch key2
            case 3
                switch id
                      case 1
                            Kp=1.086*(T/L)^0.869/K;Ti=T/(0.740-0.13*L/T);Td=0.348*T*(L/T)^0.914;
                      case 2
                            Kp=0.965*(T/L)^0.85/K;Ti=T/(0.796-0.1465*L/T);Td=0.308*T*(L/T)^0.929;
                end
                if L/T>1
                    key=2;lb=1;
                elseif L/T<0.1
                    key=3;lb=0.1;
                else
                   key=1;
                end
        end
end