Any suggestions of Q and R to my LQR representation to get reasonable step response?

This is below my code :

% Define the matrix A, B, C, D

A=[0,1,0,0;0,-42.44,212.24,0;0,0,0,1;0,0,0,-42.44];

B=[0,0;106.12,-5;0,0;78.6,-42.44];

C=[1,0,0,0;0,1,0,0;0,0,1,0;0,0,0,1];

D=[0];

%Detect the controllability of the Given system

Qc= ctrb(A,B);

rank_of_Qc = rank(Qc)

x = 1;

Q = diag([x 0 0 0]);

R=[0.9,0;0,0.9];

K=lqr(A,B,Q,R)

%Find step response of LQR controller

LQRcontroller_sys=ss(A-B*K,B,C,D)

t=0:0.1:10;

step(LQRcontroller_sys,t)

grid on;

This is my results

My system

[Raj]

What do you mean by "reasonable step response"? You can tune the LQR weight matrices (Q & R) to get whatever output response you need. Depends on what you want to achieve.