Scale in sonar widget not correct

[alcantara09]

Comparing the data from the sonar samples and the visualization in the sonar widget, it is possible to notice that the visualization is not correct. I would say that is 10 times smaller.

[romulogcerqueira]

@alcantara09 , could you give us more details?

[alcantara09]

@romulogcerqueira ,
the error is in the sonar widget. In fact, I think the range is not being applied to the visualization. No matter which range you choose in the widget, the readings from the sonar remains at the same scale.

and the script to that produces the error is just running the sonar simulation component and the sonar widget as this one

`require 'rock/bundles'
require 'vizkit'
require 'rock/gazebo'

include Orocos
Bundles.initialize

model_path = File.join(Dir.pwd, 'models','sdf')
world_path = File.join(Dir.pwd, 'scenes','uw_structures', 'uw_structures.world')

Execute the task

Bundles.run 'imaging_sonar_simulation::ScanningSonarTask' => 'sonar_sim' do

## Get the specific task context ##
sonar_sim = Bundles.get 'sonar_sim'
#set an array with model paths
sonar_sim.model_paths = [model_path]
#path to world file
sonar_sim.world_file_path = world_path
## Configure the tasks ##
sonar_sim.configure

sonar_gui = Vizkit.default_loader.SonarWidget
sonar_sim.sonar_samples.connect_to sonar_gui 

## Start the tasks ##
sonar_sim.start

#input with at the origin with 0 velocities
rbs = Types::Base::Samples::RigidBodyState.new
rbs.position = Eigen::Vector3.new(0,0,0)
rbs.orientation = Eigen::Quaternion.new(0,0,0,1)

sim_pose_writer = sonar_sim.sonar_pose_cmd.writer
timer = Qt::Timer.new
timer.connect(SIGNAL('timeout()')) do
    sim_pose_writer.write(rbs)
end

# start the timer with a timeout of 10 ms
timer.start(10)
sonar_gui.show
Vizkit.exec 

end`

[romulogcerqueira]

Hi @alcantara09,

I had a look at your script code and apparently it is not a problem in sonar widget and/or sonar simulation. You need to connect the task properties with the sonar widget sliders. Please perform the following steps:

• Insert these lines after sonar_sim.sonar_samples.connect_to sonar_gui :

  ## Set the signals ##
  sonar_gui.connect(SIGNAL('rangeChanged(int)')) do |value|
    sonar_sim.range = value
  end
  
  sonar_gui.connect(SIGNAL('gainChanged(int)')) do |value|
    sonar_sim.gain = value * 1.0 / 100.0
  end

• If the problem is still happenning, open rock-display and try to change the properties range and gain manually.

Please let me know your attempts.

[doudou]

You need to connect the task properties with the sonar widget sliders. Please perform the following steps:

You are not computing the ranges from the sonar data ?

[romulogcerqueira]

You are not computing the ranges from the sonar data ?

Sorry @doudou, I didn't understand your question. range is a property of imaging_sonar_simulation. If we wish to change its value runtime using script and sonar widget, we need to set the signals of sonar widget gui.

[doudou]

The max range is in effect embedded in the sonar data structure (bin_duration * bin_count * speed_of_sound). IMO visualization should match what's there. The max_range control should really only be that, a control.

[doudou]

The problem here is that the sonar widget is completely broken when used in e.g. rock-display, which is still the primary use case, and due to vizkit limitations there's no way to automatically plug the range to the sonar component when opening a sonar display.

[romulogcerqueira]

The max range is in effect embedded in the sonar data structure (bin_duration * bin_count * speed_of_sound).

I agree with you. This makes sense in the most sonar devices (like Tritech DST Micron), however Tritech Gemini and Teledyne Blueview sonars have a range compression which limits the bin_count between 750 -1500 bins, and its value is not proportional to range one (e.g. we can have 1350 bins at 20m and 900 bins at 25m).

[romulogcerqueira]

IMO visualization should match what's there. The max_range control should really only be that, a control.

In this case, when the range value is changed, the bin_count will also be changed, right? Currently in sonar simulation the bin_count is not dependent of range value. I can fix it now we have a dynamic shader image.

[doudou]

Range is controlled by two parameters, the bin_count and the time-per-bin. The latter is usually what's used to control, since one likely uses the max. bin count of the sonar (to get the best resolution)

[doudou]

(I'm not even sure that one can change the bin count in practice .... I don't see any benefit in doing so)

[romulogcerqueira]

Range is controlled by two parameters, the bin_count and the time-per-bin. The latter is usually what's used to control, since one likely uses the max. bin count of the sonar (to get the best resolution)
(I'm not even sure that one can change the bin count in practice .... I don't see any benefit in doing so)

My mistake, sorry! As you said, we already have this relationship in the sonar simulation here to define bin_duration. It is not needed to change the bin_count when the range is changed.

[romulogcerqueira]

@doudou , I'm in vacations in this month, however I will try to keep tracking here as soon as possible.