function [Kp,Ti,Td,key,lb]=pid_chr_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 2
                   switch id
                       case 1
                           Kp=0.6*T/(K*L);Ti=4*L;
                       case 2
                           Kp=0.7*T/(K*L);Ti=2.33*L/K;
                   end
               case 3
                 switch id
                     case 1
                           Kp=0.35*T/(K*L);Ti=1.17*T;
                     case 2
                           Kp=0.6*T/(K*L);Ti=T;
                  end
            end
         if 0.11<L/T&L/T<1.0
               key=1;
         elseif L/T>=1.0
               key=2;lb=1.0;
         else
               key=3;lb=0.11;
         end
    case 2
        switch key2
            case 1
                    switch id
                        case 1
                            Kp=0.95*T/(K*L);Ti=2.38*L;Td=0.42*L;
                        case 2
                            Kp=1.2*T/(K*L);Ti=2*L;Td=0.42*L;
                        case 3
                            Kp=0.6*T/(K*L);Ti=T;Td=0.5*L;
                        case 4
                            Kp=0.95*T/(K*L);Ti=0.36*T;Td=0.47*L;
                     end
                if 0.11<L/T&L/T<1.0
                      key=1;
                elseif L/T>1.0
                      key=2;lb=1.0;
                else
                      key=3;lb=0.11;
                end
        end
end