diff --git a/Activation.h b/Activation.h
index 7ff0b0b..546cb28 100644
--- a/Activation.h
+++ b/Activation.h
@@ -6,6 +6,7 @@
 namespace Passer {
 namespace RoboidControl {
 
+/// @brief Activation function for control
 class Activation {
  public:
   static float HeavisideStep(float inputValue, float bias = 0);  // Range: {0,1}
diff --git a/DifferentialDrive.cpp b/DifferentialDrive.cpp
index f7ab168..bab2f3f 100644
--- a/DifferentialDrive.cpp
+++ b/DifferentialDrive.cpp
@@ -38,3 +38,14 @@ void DifferentialDrive::SetTwistSpeed(float forward, float yaw) {
   float rightSpeed = Float::Clamp(forward + yaw, -1, 1);
   SetTargetSpeeds(leftSpeed, rightSpeed);
 }
+
+void DifferentialDrive::SetTwistSpeed(Vector2 linear, float yaw) {
+  SetTwistSpeed(linear.y, yaw);
+}
+
+void DifferentialDrive::SetTwistSpeed(Vector3 linear,
+                                      float yaw,
+                                      float pitch,
+                                      float roll) {
+  SetTwistSpeed(linear.z, yaw);
+}
diff --git a/DifferentialDrive.h b/DifferentialDrive.h
index 1ad7bad..8eed5db 100644
--- a/DifferentialDrive.h
+++ b/DifferentialDrive.h
@@ -5,15 +5,57 @@
 namespace Passer {
 namespace RoboidControl {
 
+/// @brief A two-wheeled Propulsion method
+///
+/// The wheels are put at either side of the roboid with the following behaviour
+/// * When both wheels spin forward, the Roboid moves forward
+/// * When both wheels spin backward, the Roboid moves backward
+/// * When both wheels are spinning in opposite directions, the Roboid rotates
+/// wihout moving forward or backward
+/// * When just one wheel is spinning, the Roboid turnes while moving forward or
+/// backward.
 class DifferentialDrive : public Propulsion {
  public:
+  /// @brief Default constructor
   DifferentialDrive();
+  /// @brief Setup of the DifferentialDrive with the Placement of the motors
+  /// @param leftMotorPlacement Placement of the left Motor
+  /// @param rightMotorPlacement Placement of the right Motor
+  /// In this setup, the left motor Direction will be CounterClockWise when
+  /// driving forward, while the right motor will turn Clockwise.
+  /// @note When not using controlled motors, the placement of the motors is
+  /// irrelevant.
   DifferentialDrive(Placement leftMotorPlacement,
                     Placement rightMotorPlacement);
+
+  /// @brief Set the target speeds of the motors directly
+  /// @param leftSpeed The target speed of the left Motor
+  /// @param rightSpeed The target speed of the right Motor
   void SetTargetSpeeds(float leftSpeed, float rightSpeed);
 
+  /// @brief Controls the motors through forward and rotation speeds
+  /// @param forward The target forward speed of the Roboid
+  /// @param yaw The target rotation speed of the Roboid
   virtual void SetTwistSpeed(float forward, float yaw) override;
-  // virtual void SetTwistSpeed(float forward, float yaw, float pitch) override;
+  /// @brief Controls the motors through forward and rotation speeds
+  /// @param linear The target linear speed of the Roboid
+  /// @param yaw The target rotation speed of the Roboid
+  /// @note As a DifferentialDrive cannot move sideward, this function has the
+  /// same effect as using the void SetTwistSpeed(float forward, float yaw)
+  /// function.
+  virtual void SetTwistSpeed(Vector2 linear, float yaw = 0.0F);
+  /// @brief Controls the motors through forward and rotation speeds
+  /// @param linear The target linear speed
+  /// @param yaw The target rotation speed around the vertical axis
+  /// @param pitch Pitch is not supported and is ignored
+  /// @param roll Roll is not supported and is ignores
+  /// @note As a DifferentialDrive cannot move sideward or vertical, this
+  /// function has the same effect as using the void SetTwistSpeed(float
+  /// forward, float yaw) function.
+  virtual void SetTwistSpeed(Vector3 linear,
+                             float yaw = 0.0F,
+                             float pitch = 0.0F,
+                             float roll = 0.0F);
 };
 
 }  // namespace RoboidControl
diff --git a/DistanceSensor.cpp b/DistanceSensor.cpp
index c1224a2..be6f62d 100644
--- a/DistanceSensor.cpp
+++ b/DistanceSensor.cpp
@@ -12,16 +12,7 @@ float DistanceSensor::GetDistance() {
   return distance;
 };
 
-void DistanceSensor::SetDistance(float distance) {
-  this->distance = distance;
-};  // for simulation purposes
-
 bool DistanceSensor::IsOn() {
   bool isOn = GetDistance() <= triggerDistance;
   return isOn;
 }
-
-bool DistanceSensor::isOff() {
-  bool isOff = GetDistance() > triggerDistance;
-  return isOff;
-}
diff --git a/DistanceSensor.h b/DistanceSensor.h
index 6f6d16b..c46f2ad 100644
--- a/DistanceSensor.h
+++ b/DistanceSensor.h
@@ -8,21 +8,26 @@ namespace RoboidControl {
 /// @brief A Sensor which can measure the distance to the nearest object
 class DistanceSensor : public Sensor {
  public:
+  /// @brief Default constructor
   DistanceSensor();
+  /// @brief Creates a DistanceSensor with the given trigger distance
+  /// @param triggerDistance The distance at which the sensors indicates that a
+  /// object is close by
   DistanceSensor(float triggerDistance);
+
   /// @brief Determine the distance to the nearest object
   /// @return the measured distance in meters to the nearest object
   virtual float GetDistance();
-  void SetDistance(float distance);
 
   /// @brief The distance at which ObjectNearby triggers
   float triggerDistance = 1;
 
+  /// @brief Indicate that an object is nearby
+  /// @return True when an object is nearby
   bool IsOn();
 
-  bool isOff();
-
  protected:
+  /// @brief Distance to the closest object
   float distance = 0;
 };
 
diff --git a/Motor.cpp b/Motor.cpp
index 3c23653..c2a2185 100644
--- a/Motor.cpp
+++ b/Motor.cpp
@@ -12,19 +12,3 @@ float Motor::GetSpeed() {
 void Motor::SetSpeed(float targetSpeed) {
   this->currentTargetSpeed = targetSpeed;
 }
-
-bool Motor::Drive(float distance) {
-  if (!this->driving) {
-    this->startTime = time(NULL);
-    this->targetDistance = distance >= 0 ? distance : -distance;
-    this->driving = true;
-  }
-  double duration = difftime(time(NULL), this->startTime);
-  if (duration >= this->targetDistance) {
-    this->driving = false;
-    return true;
-  }
-
-  SetSpeed(distance < 0 ? -1 : 1);  // max speed
-  return false;
-}
\ No newline at end of file
diff --git a/Motor.h b/Motor.h
index 5506678..737e7ff 100644
--- a/Motor.h
+++ b/Motor.h
@@ -27,13 +27,8 @@ class Motor : public Thing {
   /// forward)
   virtual float GetSpeed();
 
-  bool Drive(float distance);
-
  protected:
   float currentTargetSpeed = 0;
-  bool driving = false;
-  float targetDistance = 0;
-  time_t startTime = 0;
 };
 
 }  // namespace RoboidControl
diff --git a/Perception.cpp b/Perception.cpp
index 788e950..78f9971 100644
--- a/Perception.cpp
+++ b/Perception.cpp
@@ -10,24 +10,6 @@ Perception::Perception(Placement* sensors, unsigned int sensorCount) {
   this->sensorPlacements = (Placement*)sensors;
 }
 
-void Perception::AddSensors(Placement* things, unsigned int thingCount) {
-  sensorCount = 0;
-  for (unsigned int thingIx = 0; thingIx < thingCount; thingIx++) {
-    Thing* thing = things[thingIx].thing;
-    if (thing->IsSensor())
-      sensorCount++;
-  }
-
-  sensorPlacements = new Placement[sensorCount];
-
-  unsigned int sensorIx = 0;
-  for (unsigned int thingIx = 0; thingIx < thingCount; thingIx++) {
-    Thing* thing = things[thingIx].thing;
-    if (thing->IsSensor())
-      sensorPlacements[sensorIx++] = things[thingIx];
-  }
-}
-
 unsigned int Perception::GetSensorCount() {
   return this->sensorCount;
 }
@@ -154,64 +136,4 @@ bool Perception::SwitchOn(float fromAngle, float toAngle) {
     }
   }
   return false;
-}
-
-unsigned int Perception::ToDepthMapIndex(float angle) {
-  unsigned int depthMapIx =
-      (unsigned int)(((angle - rangeMinimum) / (rangeMaximum - rangeMinimum)) *
-                     (float)resolution);
-  return depthMapIx;
-}
-
-float Perception::GetDistance(float angle) {
-  if (depthMap != nullptr) {
-    if (angle < rangeMinimum || angle > rangeMaximum)
-      return INFINITY;
-    unsigned int depthMapIx = ToDepthMapIndex(angle);
-    return depthMap[depthMapIx];
-  } else {
-    for (unsigned int sensorIx = 0; sensorIx < this->sensorCount; sensorIx++) {
-      Placement placement = sensorPlacements[sensorIx];
-      float placementAngle = placement.horizontalDirection;
-      if (placementAngle == angle) {
-        DistanceSensor* distanceSensor = (DistanceSensor*)placement.thing;
-        return distanceSensor->GetDistance();
-      }
-    }
-  }
-  return INFINITY;
-}
-
-void Perception::SetResolution(unsigned int resolution) {
-  this->resolution = resolution;
-  this->depthMap = new float[this->resolution];
-}
-
-void Perception::SetRange(float min, float max) {
-  this->rangeMinimum = min;
-  this->rangeMaximum = max;
-}
-
-float* Perception::GetDepthMap() {
-  return this->depthMap;
-}
-
-void Perception::SetDepthMap(float angle, float distance) {
-  if (angle < rangeMinimum || angle > rangeMaximum)
-    return;
-
-  unsigned int depthMapIx = ToDepthMapIndex(angle);
-  depthMap[depthMapIx] = distance;
-}
-
-Sensor* Perception::GetSensor(float angle) {
-  angle = Angle::Normalize(angle);
-
-  for (unsigned int ix = 0; ix < this->sensorCount; ix++) {
-    Placement placement = this->sensorPlacements[ix];
-    if (abs(placement.horizontalDirection - angle) < 0.01F)
-      return (Sensor*)placement.thing;
-  }
-
-  return nullptr;
 }
\ No newline at end of file
diff --git a/Perception.h b/Perception.h
index ae5ee0c..7e22154 100644
--- a/Perception.h
+++ b/Perception.h
@@ -6,9 +6,10 @@
 namespace Passer {
 namespace RoboidControl {
 
+/// @brief Module to which keeps track of objects around the roboid
 class Perception {
  public:
-  /// @brief Setup perception
+  /// @brief Default Constructor
   Perception();
 
   /// @brief Template to make it possible to leave out ths sensorCount
@@ -18,14 +19,31 @@ class Perception {
   inline Perception(Placement (&sensors)[sensorCount]) {
     Perception(sensors, sensorCount);
   }
+  /// @brief Create a perception setup with the given Sensors
+  /// @param sensors The Placement of Sensors on the Roboid
+  /// @param sensorCount The number of sensors in the placement array
   Perception(Placement* sensors, unsigned int sensorCount);
 
-  void AddSensors(Placement* sensors, unsigned int sensorCount);
-
+  /// @brief Get the number of Sensors
+  /// @return The number of sensors, zero when no sensors are present
   unsigned int GetSensorCount();
-  Sensor* GetSensor(unsigned int sensorId);
+  /// @brief Get a specific Sensor on the Roboid
+  /// @param sensorId The index of the Sensor
+  /// @return The requested Sensor or a nullptr when no Sensor with the given
+  /// index could be found
+  Sensor* GetSensor(unsigned int sensorIx);
+  /// @brief Get the placement of a specific Sensor
+  /// @param motorIx The index of the Sensor
+  /// @return Returns the Placement or a nullptr when no Placement with the
+  /// given index could be found
+  Placement* GetSensorPlacement(unsigned int sensorIx);
 
-  float DistanceForward(float angle = 90);
+  /// @brief Distance to the closest object on the front of the Roboid
+  /// @param direction The direction relative to the forward direction in which
+  /// the object should be present
+  /// @return The distance to the closest object within the given range,
+  /// INFINITY when no object is detected
+  float DistanceForward(float direction = 90);
 
   /// @brief Distance to the closest object on the left
   /// @return distance in meters, INFINITY when no object is detected.
@@ -57,33 +75,39 @@ class Perception {
   /// @note When an object is beyond `angle` meters, it is not reported.
   float DistanceRight(float angle);
 
+  /// @brief Distance to the closest object above the Roboid
+  /// @return distance in meters, INFINITY when no object is detected
   float DistanceUp() { return DistanceUp(180); }
+  /// @brief Distance to the closest object above the Roboid within the give
+  /// range
+  /// @param angle The angle relative to the upward direction to indicate the
+  /// range
+  /// @return distance in meters, INFINITY when no object is detected
   float DistanceUp(float angle);
+  /// @brief Disatnce to the closest object under the Roboid
+  /// @return distance in meters, INFINITY when no object is detected
   float DistanceDown() { return DistanceDown(180); }
+  /// @brief Distance to the closest object under th4e Roboid within the given
+  /// range
+  /// @param angle The angle relative to the downward direciton to indicate the
+  /// range
+  /// @return distance in meters, INFINITY when no object is detected
   float DistanceDown(float angle);
 
-  float Distance(float leftAngle, float rightAngle);
-  float GetDistance(float angle);
-
+  /// @brief Checks if an object is close within the give range in the
+  /// horizontal plane
+  /// @param fromAngle Start angle in the horizontal plane
+  /// @param toAngle End angle in the horizontal plane
+  /// @return True is an object is closeby
+  /// @note Whether an object is closeby depends on the Distance Sensor
+  /// @remark This function is likely to change in the near future
   bool SwitchOn(float fromAngle, float toAngle);
 
-  void SetResolution(unsigned int resolution);
-  void SetRange(float min, float max);
-  float* GetDepthMap();
-  unsigned int ToDepthMapIndex(float angle);
-  void SetDepthMap(float angle, float distance);
-
-  Sensor* GetSensor(float angle);
-
  protected:
-  // SensorPlacement* sensors = nullptr;
+  /// @brief The Placement of the Sensors used for Perception
   Placement* sensorPlacements = nullptr;
+  /// @brief The number of Sensors used for Perception
   unsigned int sensorCount = 0;
-
-  unsigned int resolution;
-  float rangeMinimum;
-  float rangeMaximum;
-  float* depthMap = nullptr;
 };
 
 }  // namespace RoboidControl
diff --git a/Propulsion.cpp b/Propulsion.cpp
index dada9fc..b1575e9 100644
--- a/Propulsion.cpp
+++ b/Propulsion.cpp
@@ -9,23 +9,6 @@ Propulsion::Propulsion() {
   this->motorCount = 0;
 }
 
-void Propulsion::AddMotors(Placement* things, unsigned int thingCount) {
-  this->motorCount = 0;
-  for (unsigned int thingIx = 0; thingIx < thingCount; thingIx++) {
-    Thing* thing = things[thingIx].thing;
-    if (thing->IsMotor())
-      motorCount++;
-  }
-  this->placement = new Placement[motorCount];
-
-  unsigned int motorIx = 0;
-  for (unsigned int thingIx = 0; thingIx < thingCount; thingIx++) {
-    Thing* thing = things[thingIx].thing;
-    if (thing->IsMotor())
-      this->placement[motorIx++] = things[thingIx];
-  }
-}
-
 unsigned int Propulsion::GetMotorCount() {
   return this->motorCount;
 }
@@ -52,13 +35,7 @@ Placement* Propulsion::GetMotorPlacement(unsigned int motorId) {
   return nullptr;
 }
 
-void Propulsion::Update(float currentTimeMs) {
-  this->lastUpdateTime = currentTimeMs;
-}
-
-void Propulsion::SetMaxSpeed(float maxSpeed) {
-  this->maxSpeed = abs(maxSpeed);
-}
+void Propulsion::Update(float currentTimeMs) {}
 
 void Propulsion::SetTwistSpeed(float forward, float yaw) {}
 
diff --git a/Propulsion.h b/Propulsion.h
index 7d58263..20d0dc1 100644
--- a/Propulsion.h
+++ b/Propulsion.h
@@ -7,47 +7,65 @@
 namespace Passer {
 namespace RoboidControl {
 
+/// @brief The Propulsion module for a Roboid is used to move the Roboid in
+/// space
+///
+/// Usually, a specific implementation of the propulsion module is used for a
+/// robot. This base class does not implement the functions to move the Roboid
+/// around.
 class Propulsion {
  public:
-  /// @brief Setup sensing
+  /// @brief Default Constructor for Propulsion
   Propulsion();
 
+  /// @brief Update the propulsion state of the Roboid
+  /// @param currentTimeMs  The time in milliseconds when calling this
   void Update(float currentTimeMs);
 
-  void AddMotors(Placement* motors, unsigned int motorCount);
-  // void AddQuadcopter(Quadcopter* quadcopter);
-  // Quadcopter* GetQuadcopter();
-
+  /// @brief Get the number of motors in this roboid
+  /// @return The number of motors. Zero when no motors are present
   unsigned int GetMotorCount();
+  /// @brief Get a specific motor
+  /// @param motorIx The index of the motor
+  /// @return Returns the motor or a nullptr when no motor with the given index
+  /// could be found
   Motor* GetMotor(unsigned int motorIx);
+  /// @brief Get the Placement of a specific Motor
+  /// @param motorIx The index of the Motor
+  /// @return Returns the Placement or a nullptr when no Placement with the give
+  /// index could be found
   Placement* GetMotorPlacement(unsigned int motorIx);
 
-  /// @brief Set the maximum linear speed.
-  /// @param maxSpeed The new maximum linear speed
-  /// For controlled motors, this is rpm.
-  /// For calibrated controlled motors, this is m/s
-  /// For uncontrolled motors this is a value between 0 and 1 where 1 is the
-  /// maximum speed of the motor
-  void SetMaxSpeed(float maxSpeed);
-
   // Velocity control
-  virtual void SetTwistSpeed(float forward, float yaw = 0.0F);   // 2D
-  virtual void SetTwistSpeed(Vector2 linear, float yaw = 0.0F);  // 2D plus
+
+  /// @brief Sets the forward and rotation speed of a (grounded) Roboid
+  /// @param forward The target forward speed
+  /// @param yaw The target rotation speed around the vertical axis
+  /// This function is typically used for Roboid which are driving on the
+  /// ground.
+  virtual void SetTwistSpeed(float forward, float yaw = 0.0F);
+  /// @brief Sets the forward, sideward and rotation speed of a (grounded)
+  /// Roboid
+  /// @param linear The target linear (forward, sideward) speed
+  /// @param yaw The target rotation speed around the vertical axis
+  /// This function is typically used for Roboid which are driving on the ground
+  /// which have to ability to move sideward
+  virtual void SetTwistSpeed(Vector2 linear, float yaw = 0.0F);
+  /// @brief Set the target 3D linear and 3D rotation speed of a (flying) Roboid
+  /// @param linear The target linear speed
+  /// @param yaw The target rotation speed around the vertical axis
+  /// @param pitch The target rotation speed around the sideward axis
+  /// @param roll The target rotation speed around hte forward axis
   virtual void SetTwistSpeed(Vector3 linear,
                              float yaw = 0.0F,
                              float pitch = 0.0F,
-                             float roll = 0.0F);  // 3D
-
-  Placement* placement = nullptr;
-  unsigned int motorCount = 0;
+                             float roll = 0.0F);
 
  protected:
-  float maxSpeed = 1;
-
-  bool driving = false;
-  float targetDistance = 0;
-  time_t startTime;
-  float lastUpdateTime;
+  /// @brief The number of motors used for Propulsion
+  unsigned int motorCount = 0;
+  /// @brief The Placement of the motors used for Propulsion
+  Placement* placement = nullptr;
 };
 
 }  // namespace RoboidControl
diff --git a/Roboid.h b/Roboid.h
index 4859c5e..964b125 100644
--- a/Roboid.h
+++ b/Roboid.h
@@ -6,16 +6,25 @@
 namespace Passer {
 namespace RoboidControl {
 
+/// @brief A Roboid is used to control autonomous robots
 class Roboid {
  public:
+  /// @brief Default constructor for a Roboid
   Roboid();
-  Roboid(Placement configuration[], unsigned int thingCount);
+  /// @brief Creates a Roboid with Perception and Propulsion abilities
+  /// @param perception The Perception implementation to use for this Roboid
+  /// @param propulsion The Propulsion implementation to use for this Roboid
   Roboid(Perception* perception, Propulsion* propulsion);
 
-  Perception* perception;
-  Propulsion* propulsion;
-
+  /// @brief Update the state of the Roboid
+  /// @param currentTimeMs The time in milliseconds when calling this
+  /// function
   void Update(float currentTimeMs);
+
+  /// @brief The Perception module of this Roboid
+  Perception* perception;
+  /// @brief The Propulsion module of this Roboid
+  Propulsion* propulsion;
 };
 }  // namespace RoboidControl
 }  // namespace Passer
diff --git a/Sensor.h b/Sensor.h
index 4f6f87a..f88906b 100644
--- a/Sensor.h
+++ b/Sensor.h
@@ -8,6 +8,7 @@ namespace RoboidControl {
 /// @brief A sensor is a thing which can perform measurements in the environment
 class Sensor : public Thing {
  public:
+  /// @brief Default Constructor for a Sensor
   Sensor();
 };