diff --git a/.gitignore b/.gitignore
index 7bbc71c..7c04a2a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -99,3 +99,6 @@ ENV/
 
 # mypy
 .mypy_cache/
+
+# configure for MacOS
+*.DS_Store
diff --git a/fr/modules/actions/action.py b/fr/modules/actions/action.py
index e51be9a..1329cd3 100644
--- a/fr/modules/actions/action.py
+++ b/fr/modules/actions/action.py
@@ -5,7 +5,7 @@ def activate(self):
         # Called when action activated
         pass
     
-    def update(self):
+    def __call__(self):
         # Called every frame while action is activated
         pass
 
diff --git a/fr/modules/actions/moveToFace.py b/fr/modules/actions/moveToFace.py
index 5e2da5e..9c87bf4 100644
--- a/fr/modules/actions/moveToFace.py
+++ b/fr/modules/actions/moveToFace.py
@@ -1,23 +1,26 @@
 # -*- coding: utf-8 -*-
 import cv2
 import math
-from ..analyzers.facedetector import FaceDetector
+from ..submodules.facedetector import FaceDetector
 
 class Noaction(object):
+    def __init__(self):
+        self.fd = FaceDetector()
+
     def activate(self):
         # Called when action activated
         return {}
     
-    def update(self):
+    def __call__(self):
         act = {
             "wheelleft": 0.0,
             "wheelright": 0.0
         }
         # Called every frame while action is activated
-        if str(FaceDetector.biggestFaceRect) != "None":
+        if str(self.fd.biggestFaceRect) != "None":
             # If face exists
-            x, _ = FaceDetector.biggestFaceRectPosNormalized(None)
-            size = FaceDetector.biggestFaceSizeNormalized(None)
+            x, _ = self.fd.biggestFaceRectPosNormalized(None)
+            size = self.fd.biggestFaceSizeNormalized(None)
             if abs(x) > 0.3:
                 if x > 0:
                     # Rotate to left
diff --git a/fr/modules/actions/noaction.py b/fr/modules/actions/noaction.py
index b4de192..1054a60 100644
--- a/fr/modules/actions/noaction.py
+++ b/fr/modules/actions/noaction.py
@@ -5,7 +5,7 @@ def activate(self):
         # Called when action activated
         return {}
     
-    def update(self):
+    def __call__(self):
         # Called every frame while action is activated
         return {}
 
diff --git a/fr/modules/actions/raiseLeftHand.py b/fr/modules/actions/raiseLeftHand.py
index f97f68c..2ee5c78 100644
--- a/fr/modules/actions/raiseLeftHand.py
+++ b/fr/modules/actions/raiseLeftHand.py
@@ -20,7 +20,7 @@ def activate(self):
         act["armleft"] = 1.0
         return act
     
-    def update(self):
+    def __call__(self):
         # Called every frame while action is activated
         pass
 
diff --git a/fr/modules/actions/raiseRightHand.py b/fr/modules/actions/raiseRightHand.py
index 833b054..1140d63 100644
--- a/fr/modules/actions/raiseRightHand.py
+++ b/fr/modules/actions/raiseRightHand.py
@@ -20,7 +20,7 @@ def activate(self):
         act["armright"] = 1.0
         return act
     
-    def update(self):
+    def __call__(self):
         # Called every frame while action is activated
         pass
 
diff --git a/fr/modules/actions/randomMove.py b/fr/modules/actions/randomMove.py
index 76057b6..f4b5651 100644
--- a/fr/modules/actions/randomMove.py
+++ b/fr/modules/actions/randomMove.py
@@ -21,7 +21,7 @@ def activate(self):
         act["armright"] = 1.0
         return act
     
-    def update(self):
+    def __call__(self):
         # Called every frame while action is activated
         act = BASE_ACTION
         act["armleft"] = math.sin(time.time() * 2)
diff --git a/fr/modules/actions/rotateLeft.py b/fr/modules/actions/rotateLeft.py
index 624dda6..959dcce 100644
--- a/fr/modules/actions/rotateLeft.py
+++ b/fr/modules/actions/rotateLeft.py
@@ -15,7 +15,7 @@ def activate(self):
         # Called when action activated
         return {}
     
-    def update(self):
+    def __call__(self):
         # Called every frame while action is activated
         act = BASE_ACTION
         act["wheelleft"] = -0.1
diff --git a/fr/modules/actions/rotateRight.py b/fr/modules/actions/rotateRight.py
index fe98458..a6a5108 100644
--- a/fr/modules/actions/rotateRight.py
+++ b/fr/modules/actions/rotateRight.py
@@ -15,7 +15,7 @@ def activate(self):
         # Called when action activated
         return {}
     
-    def update(self):
+    def __call__(self):
         # Called every frame while action is activated
         act = BASE_ACTION
         act["wheelleft"] = 0.1
diff --git a/fr/modules/actions/searchFaces.py b/fr/modules/actions/searchFaces.py
index 9af3727..b3b0866 100644
--- a/fr/modules/actions/searchFaces.py
+++ b/fr/modules/actions/searchFaces.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 import time
 import math
-from ..analyzers.facedetector import FaceDetector
+from ..submodules.facedetector import FaceDetector
 
 BASE_ACTION = {
     "armleft": 0.0,
@@ -12,7 +12,7 @@
 
 class SearchFaces(object):
     def __init__(self):
-        pass
+        self.fd = FaceDetector()
 
     def activate(self):
         # Called when action activated
@@ -20,7 +20,7 @@ def activate(self):
     
     def update(self):
         # Called every frame while action is activated
-        facerect = FaceDetector.getFacerect(None)
+        facerect = self.fd.getFacerect(None)
         act = BASE_ACTION
         if str(facerect) != "None" and len(facerect) > 0:
             act["wheelleft"] = 0.0
diff --git a/fr/modules/analyzers/analyzer.py b/fr/modules/analyzers/analyzer.py
index 7edaa4d..d4b5675 100644
--- a/fr/modules/analyzers/analyzer.py
+++ b/fr/modules/analyzers/analyzer.py
@@ -4,6 +4,6 @@ class Analyzer(object):
     def __init__(self):
         pass
 
-    def analyze(self, observation):
+    def __call__(self, observation):
         # Return scholar (not vector or dict)
         pass
\ No newline at end of file
diff --git a/fr/modules/analyzers/faceXAxis.py b/fr/modules/analyzers/faceXAxis.py
index 0cc7b16..53e0c4f 100644
--- a/fr/modules/analyzers/faceXAxis.py
+++ b/fr/modules/analyzers/faceXAxis.py
@@ -1,9 +1,11 @@
 # -*- coding: utf-8 -*-
 import cv2
-from .facedetector import FaceDetector
+from ..submodules.facedetector import FaceDetector
 
 class FaceXAxis(object):
+    def __init__(self):
+        self.fd = FaceDetector()
     
-    def analyze(self, observation):
-        x, _ = FaceDetector.biggestFaceRectPosNormalized(observation)
+    def __call__(self, observation):
+        x, _ = self.fd.biggestFaceRectPosNormalized(observation)
         return x
diff --git a/fr/modules/analyzers/faceYAxis.py b/fr/modules/analyzers/faceYAxis.py
index 5fa35ed..b04e8a3 100644
--- a/fr/modules/analyzers/faceYAxis.py
+++ b/fr/modules/analyzers/faceYAxis.py
@@ -1,9 +1,11 @@
 # -*- coding: utf-8 -*-
 import cv2
-from .facedetector import FaceDetector
+from ..submodules.facedetector import FaceDetector
 
 class FaceYAxis(object):
+    def __init__(self):
+        self.fd = FaceDetector()
     
-    def analyze(self, observation):
-        _, y = FaceDetector.biggestFaceRectPosNormalized(observation)
+    def __call__(self, observation):
+        _, y = self.fd.biggestFaceRectPosNormalized(observation)
         return y
diff --git a/fr/modules/analyzers/isFaceExist.py b/fr/modules/analyzers/isFaceExist.py
index 2e19e56..6a2d7e2 100644
--- a/fr/modules/analyzers/isFaceExist.py
+++ b/fr/modules/analyzers/isFaceExist.py
@@ -1,12 +1,14 @@
 # -*- coding: utf-8 -*-
 import cv2
 import time
-from .facedetector import FaceDetector
+from ..submodules.facedetector import FaceDetector
 
 class IsFaceExist(object):
+    def __init__(self):
+        self.fd = FaceDetector()
     
-    def analyze(self, observation):
-        facerect = FaceDetector.getFacerect(observation)
+    def __call__(self, observation):
+        facerect = self.fd.getFacerect(observation)
         if str(facerect) == "None": return
         if len(facerect) > 0:
             return 1.0
diff --git a/fr/modules/analyzers/facedetector.py b/fr/modules/submodules/facedetector.py
similarity index 72%
rename from fr/modules/analyzers/facedetector.py
rename to fr/modules/submodules/facedetector.py
index f772217..a5cf8a2 100644
--- a/fr/modules/analyzers/facedetector.py
+++ b/fr/modules/submodules/facedetector.py
@@ -2,19 +2,21 @@
 import cv2
 import time
 
+# Constants
 # cascade_path = "./haarcascades/haarcascade_frontalface_default.xml"
 cascade_path = "/var/opencv/haarcascades/haarcascade_frontalface_default.xml"
+# refresh rate
+refreshRate = 0.1 # sec
 
 class FaceDetector(object):
-    facerect = None
-    refreshRate = 0.1 # sec
-    lastRefreshed = 0.0 # sec
+    def __init__(self):
+        self.facerect = None
+        self.lastRefreshed = 0.0 # sec
 
-    @classmethod
     def getFacerect(self, observation):
         # Return cached data or not
-        if (time.time() - FaceDetector.lastRefreshed) < FaceDetector.refreshRate or observation == None:
-            return FaceDetector.facerect
+        if (time.time() - self.lastRefreshed) < refreshRate or observation == None:
+            return self.facerect
 
         # Engray image
         if str(observation["image"]) == "None": return
@@ -24,7 +26,7 @@ def getFacerect(self, observation):
         cascade = cv2.CascadeClassifier(cascade_path)
 
         # Get facerect
-        FaceDetector.facerect = cascade.detectMultiScale(
+        self.facerect = cascade.detectMultiScale(
             image_gray, 
             scaleFactor = 1.1,
             minNeighbors = 2,
@@ -32,24 +34,21 @@ def getFacerect(self, observation):
         )
 
         # Update cache time
-        FaceDetector.lastRefreshed = time.time()
+        self.lastRefreshed = time.time()
 
-        return FaceDetector.facerect
+        return self.facerect
 
-    @classmethod
     def biggestFaceRect(self, observation):
-        facerect = self.getFacerect(observation)
-        if str(facerect) == "None": return
-        return max(facerect, key= (lambda r: r[2] * r[3]))
+        self.facerect = self.getFacerect(observation)
+        if str(self.facerect) == "None": return
+        return max(self.facerect, key= (lambda r: r[2] * r[3]))
     
-    @classmethod
     def biggestFaceSizeNormalized(self, observation):
         width, height, _ = observation["image"].shape
         biggestface = self.biggestFaceRect(observation)
         if str(biggestface) == "None": return 0.0
         return biggestface[2] * biggestface[3] / width / height
 
-    @classmethod
     def biggestFaceRectPosNormalized(self, observation):
         width, height, _ = observation["image"].shape
         biggestface = self.biggestFaceRect(observation)