opticflow module #1062

dewagter · 2015-01-07T12:56:34Z

todo

investigate the changes of @gautierhattenberger and use the best approach
move conf
remove submodule

flixr · 2015-01-07T13:01:52Z

sw/airborne/modules/computer_vision/OpticFlow/OpticFlowHover.xml

+    <define name="USE_ARDRONE_VIDEO" />
+      <raw>
+
+include $(PAPARAZZI_HOME)/sw/ext/ardrone2_vision/Makefile.paths


should be PAPARAZZI_SRC not PAPARAZZI_HOME

dewagter · 2015-01-13T19:36:14Z

how about this... anyone wants to make the code look better?

gautierhattenberger · 2015-01-13T21:48:55Z

sw/airborne/modules/computer_vision/cv/resize.h

@@ -36,13 +36,13 @@ inline void resize_uyuv(struct img_struct *input, struct img_struct *output, int
      *dest++ = *source++; // U
      *dest++ = *source++; // Y
      // now skip 3 pixels
-      if (pixelskip) { source += (pixelskip + 1) * 2; }
+      source += (pixelskip + 1) * 2;


I would like to keep my version, otherwise it doesn't work with downsample=1 (which makes a copy of the image)

…rking with downsample=1 (copy)

gautierhattenberger · 2015-01-14T10:21:10Z

Thanks. Just one thing missing: in sw/ground_segment/tmtc/server_globals.ml:7 and sw/ground_segment/cockpit/livel.ml:1268 you should add the new mode name (or short name, MOD)

…in a module

flixr · 2015-01-15T15:02:40Z

sw/airborne/firmwares/rotorcraft/guidance/guidance_module.h

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2008-2009 Antoine Drouin <[email protected]>


Could you please correctly put your name in here?

flixr · 2015-01-28T21:27:45Z

There are also some other potential issues, like calling my_plugin_run from the computervision thread.
Access to state interface is not thread safe!

to get the scale when computing velocity from flow

flixr · 2015-01-28T21:51:04Z

conf/modules/cv_opticflow.xml

+  <periodic fun="opticflow_module_run()" freq="60" start="opticflow_module_start()" stop="opticflow_module_stop()" autorun="TRUE"/>
+  <makefile target="ap">
+    <define name="ARDRONE_VIDEO_PORT" value="2002" />
+    <define name="USE_ARDRONE_VIDEO" />


What is this supposed to be good for, seems unused to me...

flixr · 2015-01-28T21:56:41Z

Tried to cleanup some more stuff and added a subscriber for AGL (to use for scale in velocity computation)...
Before we merge this, it should really be tested...

Accessing the state interface from a thread is probably not a good idea, you can be lucky and it works, but there is no guarantee that you don't try to read it while it is currently updated...

gautierhattenberger · 2015-01-28T22:40:06Z

AP_MODE_MODULE is not the best, but good enough I guess until we can generate modes

dewagter · 2015-01-29T08:46:37Z

@flixr thank for the updates.

This multithread design initially used UDP to send data from one program to the next: https://github.com/tudelft/ardrone2_vision/blob/master/modules/ObstacleAvoidSkySegmentation/sky_seg_avoid_gst.c#L82

I don't know at which point in time this got lost...

gautierhattenberger · 2015-01-29T09:49:55Z

sw/airborne/modules/computer_vision/opticflow/visual_estimator.c

+static void agl_cb(uint8_t sender_id __attribute__((unused)), const float *distance)
+{
+  if (distance > 0) {
+    estimator_agl = *distance;


In this particular case, the data is read only and the copy is atomic, so it will be thread safe.
But testing the pointer is not correct ;)

if (*distance > 0) {

Thanks for catching this!
And yes, this one is thread safe, otherwise I wouldn't have added it ;-)

flixr · 2015-01-29T12:03:28Z

And sending telemetry messages via DOWNLINK_SEND_x or pprz_msg_send_x is also not thread safe...
So I would suggest to move the downlink of OF_HOVER to somewhere else and also compute V_body in hover_stabilization which is the only other place that actually uses this.

dewagter · 2015-01-30T08:39:41Z

I would prefer to make it 100% safe again: define 1 struct that goes from
pprz->thread and 1 struct that goes from thread->pprz and have all
navigation (fetching state) and messages in the module.

(this was the setup from the start, but after 3 people worked on it, it
changed along the road...)

Any better idea than UDP transfer? (this also makes it possible to run a
separate program instead of a thread)

-Christophe

On Thu, Jan 29, 2015 at 1:03 PM, Felix Ruess [email protected]
wrote:

And sending telemetry messages via DOWNLINK_SEND_x or pprz_msg_send_x is
also not thread safe...
So I would suggest to move the downlink of OF_HOVER to somewhere else and
also compute V_body in hover_stabilization which is the only other place
that actually uses this.

—
Reply to this email directly or view it on GitHub
#1062 (comment).

flixr · 2015-01-30T09:36:15Z

At least use a unix domain socket instead of a udp socket...
Ideally we would just send it via ABI and it would handle that in the background...

flixr · 2015-02-02T21:55:34Z

@dewagter see my opticflow_socket branch with a dummy example on how you could use unix domain sockets to pass results from the thread, specifically flixr@dfa33e4

Add cv_opticflow.xml module. Used to for hover stabilization on an ARDrone2. Also adds AP_MODE_MODULE to make it easier to add extra "external" control loops.

move computervision to modules

c84c570

flixr added the Module label Jan 7, 2015

flixr reviewed Jan 7, 2015
View reviewed changes

dewagter added 6 commits January 12, 2015 20:47

Re-organize in new dir structure

4a8105f

Code style (new)

e2249dd

[opticflow] docs and settings

535e09c

[opticflow] remove unused

0712376

[opticflow] messages

b4ae64c

[opticflow] airframe

57b1453

dewagter force-pushed the opticflow branch from 3d04c86 to 57b1453 Compare January 13, 2015 18:36

dewagter added 5 commits January 13, 2015 19:46

[opticflow] cleanup

306d04e

[opticflow] compile

e3377aa

[opticflow] controller

98c27f2

Merge branch 'master' of github.com:paparazzi/paparazzi into opticflow

a7f42a6

[opticflow] activate and set height

715125a

gautierhattenberger reviewed Jan 13, 2015
View reviewed changes

dewagter added 2 commits January 14, 2015 09:34

[opticflow] remove unused and use global paths

348e825

[opticflow] Resize function fix: keep color together and also keep wo…

cacecab

…rking with downsample=1 (copy)

dewagter and others added 6 commits January 14, 2015 14:58

[opticflow] fix removal of small

54ed9ea

[opticflow] default gains

cbf1d9e

[opticflow] documentation update

1f8fa93

removed comments in optic flow code

41095c0

[module-ctrl] GCS name of module control

0ab7a71

[module-ctrl] Generic framework to add many new types of controllers …

7a0f034

…in a module

flixr reviewed Jan 15, 2015
View reviewed changes

flixr added 3 commits January 28, 2015 21:58

[opticflow] cleanup exported functions

00d2d3d

[opticflow] rename my_plugin to opticflow_plugin

aa1317b

[opticflow] remove unused guidance_module_run

7eb4a86

flixr added 2 commits January 28, 2015 22:35

[opticflow] cosmetics: max line length

5a7e862

[opticflow] get AGL via ABI

067f91c

to get the scale when computing velocity from flow

flixr reviewed Jan 28, 2015
View reviewed changes

[opticflow] remove unused USE_ARDRONE_VIDEO define

9df34e1

[opticflow] more cleanup

ee596bc

gautierhattenberger reviewed Jan 29, 2015
View reviewed changes

[opticflow] fix distance check

374be65

[opticflow] more cleanup

17a839e

flixr added 2 commits February 2, 2015 22:48

[opticflow] compute V_body in hover_stabilization

f188864

[opticflow] example using unix domain sockets to return thread results

dfa33e4

dewagter and others added 5 commits February 5, 2015 17:28

convert to thread-communication

ec745f0

fix thread communication

1431548

Messages in module instead of thread

5589274

[opticflow] working variables in a struct

11d94d7

[opticflow] dox

5fd3808

flixr added a commit that referenced this pull request Feb 5, 2015

Merge pull request #1062 from paparazzi/opticflow

17b200a

Add cv_opticflow.xml module. Used to for hover stabilization on an ARDrone2. Also adds AP_MODE_MODULE to make it easier to add extra "external" control loops.

flixr merged commit 17b200a into master Feb 5, 2015

flixr deleted the opticflow branch February 5, 2015 21:04

flixr added this to the v5.6 milestone Feb 10, 2015

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opticflow module #1062

opticflow module #1062

dewagter commented Jan 7, 2015

flixr Jan 7, 2015

dewagter commented Jan 13, 2015

gautierhattenberger Jan 13, 2015

gautierhattenberger commented Jan 14, 2015

flixr Jan 15, 2015

flixr commented Jan 28, 2015

flixr Jan 28, 2015

flixr commented Jan 28, 2015

gautierhattenberger commented Jan 28, 2015

dewagter commented Jan 29, 2015

gautierhattenberger Jan 29, 2015

flixr Jan 29, 2015

flixr commented Jan 29, 2015

dewagter commented Jan 30, 2015

flixr commented Jan 30, 2015

flixr commented Feb 2, 2015

		@@ -0,0 +1,51 @@
		/*
		* Copyright (C) 2008-2009 Antoine Drouin <[email protected]>

opticflow module #1062

opticflow module #1062

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dewagter commented Jan 7, 2015

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