diff --git a/README.md b/README.md
index 2d97c024a7745a0ad16e123f31f1ad8534dc9330..e1e72481a1839ab7e2aff01ccb4941a2173d98ac 100644
--- a/README.md
+++ b/README.md
@@ -15,3 +15,6 @@ the file is in the utills important
 
 issue with device permission usb crazyflie 
 https://www.bitcraze.io/documentation/repository/crazyflie-lib-python/master/installation/usb_permissions/
+
+# Important observation 
+Due to the noise in the sensor data, the pid controller is not exact. A better approach if time permit is to implement a kalman filter for the sensor data, to better improve the pid controller