diff --git a/Main.m b/Main.m
index 9436b30..bcc187b 100644
--- a/Main.m
+++ b/Main.m
@@ -2,32 +2,58 @@
 clc; 
 close all;
 
+%% Check List:
+% 1.Power on Robot Dog
+% 2.Connect Robot Dog Wifi: Unitree_Go393319A
+% 3.Open Virtual Machine
+% 4.Running /Desktop/unitree_matlab/build/udp_link press Enter to begin
+% 5.Open Motive Check Broadcast and Network Interface
+% 6.You are good for running 
+
+%% Robot Dog Network Parameters
 % this IP is the vm ip
 Robot_Dog_IP = '192.168.12.184';
 Robot_Dog_Port = 1145;
 
+%% Robot Dog Command Initialized
 Control_Command = zeros(1,11,'single');
-%% Motive coordiate frame
-% wall wall wall wall wall
-%        ^ z
-%        |
-%        |
-% x <----O y(pointing up)
-% wall computer wall
-
-
-%% System Parameters
 
+%% Feedback Control Parameters
 K_P = 0.5; % Porportional constant on velocity action
 K_I = 1;  % Integral
 K_D = 1;
 % constant on velocity action
 K_Y = pi/180; % Proportional constant on angle action
 
+%% Control Setting 
+% Mode 1: Dog will keep face to yaw_set and move to target point.
+% Mode 2: Dog will turn to target point and walk to it.
+
+Control_Mode=1;
+Target_Point=[0 0];
+yaw_set = -1; 
+
+% [0,360)
+% -1: Disable yaw control
+
+% wall wall wall wall wall
+%           0
+%           ^ z
+%           |
+%           |
+% 90 x <----O      270
+%
+%          180
+%
+% wall computer wall
 
 %% Instantiate client object to run Motive API commands
-% https://optitrack.com/software/natnet-sdk/
 
+% Check list:
+% 1.Broadcast Frame Date
+% 2.Network Interface: Local Loopback
+
+% https://optitrack.com/software/natnet-sdk/
 % Create Motive client object
 dllPath = fullfile('d:','StDroneControl','NatNetSDK','lib','x64','NatNetML.dll');
 assemblyInfo = NET.addAssembly(dllPath); % Add API function calls
@@ -39,10 +65,8 @@
 
 Dog_ID = 1; % Rigid body ID of the drone from Motive
 
-Target_Point=[0 0];
-yaw_set = 0;
-
 %% figure for movtion track
+[Dog_Pos] = Get_Dog_Postion(theClient, Dog_ID); %[time, z, x, yaw]
 fig = figure();
 ax = axes('Parent',fig);
 line_handle = plot(ax,Dog_Pos(3),Dog_Pos(2),'o');
@@ -52,50 +76,63 @@
 
 arrow_length=0.2;
 
-
-%%
-% while true
-%     [Dog_Pos] = Get_Dog_Postion(theClient, Dog_ID);
-% 
-% end
-
 %velocity walking
 Control_Command(1)=2; 
 %% Robot dog command
+%     Control_Command()
 %
 %     +(11) +(9)  -(11)
+%             |
 %     +(10)  dog  -(10)
+%             |
 %           -(9)
 %
-%%
+%% Motive coordiate frame
+% wall wall wall wall wall
+%        ^ z
+%        |
+%        |
+% x <----O y(pointing up)
+% wall computer wall
+%% Loop 
 while true
+    % get position from camera
     [Dog_Pos] = Get_Dog_Postion(theClient, Dog_ID); %[time, z, x, yaw]
-    
-    error_Z = Target_Point(1)-Dog_Pos(2);
-    error_X = -Target_Point(2)-Dog_Pos(3);
-    
-    disp(error_X);
 
-    error_yaw = yaw_set-Dog_Pos(4);
+    %% feedback control
+    if Control_Mode == 1
+        if yaw_set == -1
+            error_yaw = yaw_set-Dog_Pos(4);
+            error_yaw_command=0;
 
-    if abs(error_yaw)>180
-        error_yaw=(360+error_yaw);
-    end
+        elseif yaw_set >=0 && yaw_set<360
+            error_yaw = yaw_set-Dog_Pos(4);
+            if abs(error_yaw)>180
+                error_yaw_command=(360+error_yaw);
+            else
+                error_yaw_command=error_yaw;
+            end
+        end
 
-    %disp(error_yaw*K_Y);
-    Control_Command(11) = error_yaw*K_Y;
+        error_Z = Target_Point(1)-Dog_Pos(2);
+        error_X = -Target_Point(2)-Dog_Pos(3);
 
-    if abs(error_yaw)<10
-        Control_Command(9) = error_Z*K_P;
-        Control_Command(10) = error_X*K_P;
-    end
+        error_Z_rotated = error_Z*cosd(error_yaw)-error_X*sind(error_yaw);
+        error_X_rotated = error_Z*sind(error_yaw)+error_X*cosd(error_yaw);
 
-    
+        Control_Command(11) = error_yaw_command*K_Y;
+        Control_Command(9) = error_Z_rotated*K_P;
+        Control_Command(10) = error_X_rotated*K_P;
 
+
+
+    end
+    disp(Control_Command);
     Robot_Dog(Robot_Dog_IP,Robot_Dog_Port,Control_Command);
 
+    %50Hz
     pause(0.02);
-
+    %% draw 
     dy=arrow_length*cosd(Dog_Pos(4));
     dx=arrow_length*sind(Dog_Pos(4));
     quiver(Dog_Pos(3),Dog_Pos(2),dx,dy,'r','LineWidth',0.2,'MaxHeadSize',2);