diff --git a/Perception.cpp b/Perception.cpp
index 67b3a30..ee577c1 100644
--- a/Perception.cpp
+++ b/Perception.cpp
@@ -52,8 +52,10 @@ float Perception::DistanceForward(float angle) {
       continue;
 
     DistanceSensor* distanceSensor = (DistanceSensor*)placement.thing;
-    float sensorAngle = placement.direction.z;
-    if (sensorAngle > 0 && sensorAngle < angle) {
+    if (placement.verticalDirection > -angle &&
+        placement.verticalDirection < angle &&
+        placement.horizontalDirection > -angle &&
+        placement.horizontalDirection < angle) {
       minDistance = fmin(minDistance, distanceSensor->GetDistance());
     }
   }
@@ -69,7 +71,7 @@ float Perception::DistanceLeft(float angle) {
       continue;
 
     DistanceSensor* distanceSensor = (DistanceSensor*)placement.thing;
-    float sensorAngle = placement.direction.y;
+    float sensorAngle = placement.horizontalDirection;
     // Serial.printf("  distance sensor: %f %f 0\n", -angle, sensorAngle);
     if (sensorAngle < 0 && sensorAngle > -angle) {
       minDistance = fmin(minDistance, distanceSensor->GetDistance());
@@ -87,7 +89,7 @@ float Perception::DistanceRight(float angle) {
       continue;
 
     DistanceSensor* distanceSensor = (DistanceSensor*)placement.thing;
-    float sensorAngle = placement.direction.y;
+    float sensorAngle = placement.horizontalDirection;
     if (sensorAngle > 0 && sensorAngle < angle) {
       minDistance = fmin(minDistance, distanceSensor->GetDistance());
     }
@@ -104,7 +106,7 @@ float Perception::DistanceUp(float angle) {
       continue;
 
     DistanceSensor* distanceSensor = (DistanceSensor*)placement.thing;
-    float sensorAngle = placement.direction.y;  // not correct!
+    float sensorAngle = placement.verticalDirection;
     if (sensorAngle > 0 && sensorAngle < angle) {
       minDistance = fmin(minDistance, distanceSensor->GetDistance());
     }
@@ -121,7 +123,7 @@ float Perception::DistanceDown(float angle) {
       continue;
 
     DistanceSensor* distanceSensor = (DistanceSensor*)placement.thing;
-    float sensorAngle = placement.direction.y;  // not correct!
+    float sensorAngle = placement.verticalDirection;
     if (sensorAngle < 0 && sensorAngle > -angle) {
       minDistance = fmin(minDistance, distanceSensor->GetDistance());
     }
@@ -135,7 +137,7 @@ bool Perception::SwitchOn(float fromAngle, float toAngle) {
 
   for (unsigned int sensorIx = 0; sensorIx < this->sensorCount; sensorIx++) {
     Placement placement = sensorPlacements[sensorIx];
-    float angle = placement.direction.y;
+    float angle = placement.horizontalDirection;
     if (angle > fromAngle && angle < toAngle) {
       Thing* thing = placement.thing;
       if (thing == nullptr)
@@ -171,7 +173,7 @@ float Perception::GetDistance(float angle) {
   } else {
     for (unsigned int sensorIx = 0; sensorIx < this->sensorCount; sensorIx++) {
       Placement placement = sensorPlacements[sensorIx];
-      float placementAngle = placement.direction.x;
+      float placementAngle = placement.horizontalDirection;
       if (placementAngle == angle) {
         DistanceSensor* distanceSensor = (DistanceSensor*)placement.thing;
         return distanceSensor->GetDistance();
@@ -208,7 +210,7 @@ DistanceSensor* Perception::GetSensor(float angle) {
 
   for (unsigned int ix = 0; ix < this->sensorCount; ix++) {
     Placement placement = this->sensorPlacements[ix];
-    if (abs(placement.direction.y - angle) < 0.01F)
+    if (abs(placement.horizontalDirection - angle) < 0.01F)
       return (DistanceSensor*)placement.thing;
   }
 
diff --git a/Placement.cpp b/Placement.cpp
index 16e8da7..32f59e0 100644
--- a/Placement.cpp
+++ b/Placement.cpp
@@ -5,20 +5,17 @@ Placement::Placement() {
   this->thing = nullptr;
 }
 
-Placement::Placement(Thing* thing, Vector3 position) {
-  this->position = position;
-  this->direction = Vector3::zero;
+Placement::Placement(Thing* thing,
+                     Vector3 position,
+                     float horizontalDirection,
+                     float verticalDirection) {
   this->thing = thing;
+  this->position = position;
+  this->horizontalDirection = horizontalDirection;
+  this->verticalDirection = verticalDirection;
 }
 
-Placement::Placement(Thing* thing, Vector3 position, float horizontalDirection) {
-  this->position = position;
-  this->direction = Vector3(0, horizontalDirection, 0);
-  this->thing = thing;
-}
-
-Placement::Placement(Thing* thing, float horizontalDirection) {
-  this->position = Vector3::zero;
-  this->direction = Vector3(0, horizontalDirection, 0);
-  this->thing = thing;
-}
+Placement::Placement(Thing* thing,
+                     float horizontalDirection,
+                     float verticalDirection)
+    : Placement(thing, Vector3::zero, horizontalDirection, verticalDirection) {}
diff --git a/Placement.h b/Placement.h
index c1d67f9..b95ba50 100644
--- a/Placement.h
+++ b/Placement.h
@@ -10,20 +10,46 @@
 namespace Passer {
 namespace RoboidControl {
 
+/// @brief A plament is used to specify where a Thing is placed on the Roboid.
 class Placement {
  public:
+  /// @brief Default constructor with a zero placement
   Placement();
-  Placement(Thing* thing, Vector3 position);
-  Placement(Thing* thing, Vector3 position, float horizontalAngle);
-  Placement(Thing* thing, float horizontalAngle);
+  /// @brief Placement of a Thing on the Roboid
+  /// @param thing The Thing which is placed
+  /// @param position The position of the Thing in carthesian coordinated
+  /// @param horizontalDirection The horizontal direction angle of the Thing
+  /// @param verticalAngle The vertical direction angle of the Thing
+  Placement(Thing* thing,
+            Vector3 position = Vector3::zero,
+            float horizontalDirection = 0.0F,
+            float verticalAngle = 0.0F);
+  /// @brief Placement of a Thing on the roboit without position
+  /// @param thing The Thing which is place
+  /// @param horizontalDirection The horizontal direction angle of the Thing
+  /// @param verticalAngle The vertical direction angle of the Thing
+  Placement(Thing* thing,
+            float horizontalDirection,
+            float verticalAnlge = 0.0F);
 
+  /// @brief The parent placement in the Roboid hierarchy
+  /// @remark Reserved for future use
   Placement* parent = nullptr;
+  /// @brief An array of children of this placement in the Roboid hierarchy
+  /// @remark Reserved for future use
   Placement** children = nullptr;
+  /// @brief The number of children of this placemet in the Roboid hierarchy
+  /// @remark Reserved for future use
   unsigned int childCount = 0;
 
-  Vector3 position;
-  Vector3 direction;
+  /// @brief The Thing which is placed
   Thing* thing;
+  /// @brief The position of the Thing in carthesian coordinates
+  Vector3 position;
+  /// @brief The angle or direction of the Thing in the horizontal plane
+  float horizontalDirection;
+  /// @brief The angle or direction of the Thing in the vertical plane
+  float verticalDirection;
 };
 
 }  // namespace RoboidControl