[paparazzi-commits] [paparazzi/paparazzi] e88118: [modules] computer_vision: adding size divergence

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/paparazzi/paparazzi
  Commit: e88118f22b49ab0f4296355eae1ad1917e5cbcf7
      
https://github.com/paparazzi/paparazzi/commit/e88118f22b49ab0f4296355eae1ad1917e5cbcf7
  Author: guidoAI <address@hidden>
  Date:   2015-07-29 (Wed, 29 Jul 2015)

  Changed paths:
    M conf/messages.xml
    M conf/modules/cv_opticflow.xml
    M sw/airborne/modules/computer_vision/opticflow/inter_thread_data.h
    M sw/airborne/modules/computer_vision/opticflow/opticflow_calculator.c
    M sw/airborne/modules/computer_vision/opticflow/opticflow_calculator.h
    A sw/airborne/modules/computer_vision/opticflow/size_divergence.c
    A sw/airborne/modules/computer_vision/opticflow/size_divergence.h
    M sw/airborne/modules/computer_vision/opticflow_module.c

  Log Message:
  -----------
  [modules] computer_vision: adding size divergence

Adds a simple algorithm to determine optical flow divergence to the optical 
flow code in Paparazzi.
It takes the optical flow vectors and evaluates how the distances between 
corners change over time.
This allows to determine the divergence, which is 0 in hover, negative when 
going up and positive when going down.

The divergence can be used, e.g., for constant divergence landings, which 
permit safe landing on
surfaces which are not at 0 altitude (roof top for instance).

Main change is the addition of size_divergence.c / h for the calculation of the 
divergence.
The other modifications call the algorithm or pass its values on to the 
Paparazzi ground station.

closes #1262