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Laser filters limit scan angle opposite way and hector mapping limit of scan range [closed]

asked 2017-08-25 19:13:31 -0500

matteopantano gravatar image

updated 2017-08-26 01:30:04 -0500

Hi guys,

As pointed in the wiki and here I have used the pacakge laser_filters with the function LaserScanAngularBoundsFilter to eliminate some points. However the filter acts on the opposite way I would like to.

image description

As in the photo attached it ispossible to see that the points eliminated are the one on the front and not on the back. So the screenshot have the points I would like to remove. At the beginning I thought, ok easy, just change the sign of the upper and lower bound. But, seems that laser filter does not work if lower bound is bigger that upper bound.

Any hints guys?

For clarity, here the actual .yaml of the image above:

scan_filter_chain:
    - name: range
      type: LaserScanAngularBoundsFilter
      params:
        lower_angle: -1.57
        upper_angle: 1.57
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Closed for the following reason the question is answered, right answer was accepted by matteopantano
close date 2018-03-06 15:47:16.132713

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answered 2017-08-25 23:24:37 -0500

Ed Venator gravatar image

What happens if you chain two filters like this?

scan_filter_chain:
  - name: range1
    type: LaserScanAngularBoundsFilter
    params:
      lower_angle: -3.14
      upper_angle: -1.57
  - name: range2
    type: LaserScanAngularBoundsFilter
    params:
      lower_angle: 1.57
      upper_angle: 3.14
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Comments

Awesome! It worked! And also hector mapping works! Here pic: picture

matteopantano gravatar imagematteopantano ( 2017-08-26 01:29:36 -0500 )edit

Would you send your codes to my mail Mr. @matteopantano? mechinengineer@gmail.com

Mekateng gravatar imageMekateng ( 2017-10-06 15:50:19 -0500 )edit

There is no code for using LaserScanFilters, maybe wiki helps how to!

matteopantano gravatar imagematteopantano ( 2017-10-09 02:05:56 -0500 )edit

Hi, I'm using an RPLIDAR A2 and I have the same need but the solution didn't work for me. Each filter is working alone but the two don't work together and the output is a scan with just one value because I've got angle_min=angle_max=1.57079660892. Can anyone help me with that? Thanks.

Jasmin gravatar imageJasmin ( 2019-08-02 05:41:44 -0500 )edit

I tried this configuration instead,

 scan_filter_chain:
- name: laser_cutoff
  type: laser_filters/LaserScanAngularBoundsFilterInPlace
  params:
    lower_angle: -1.5708
    upper_angle: 1.5708

It kind of worked because I'm left with the front part of the scan but the range of the output scan is like the input scan and not 180° as I need it to be.

Jasmin gravatar imageJasmin ( 2019-08-02 05:50:27 -0500 )edit

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Asked: 2017-08-25 19:13:31 -0500

Seen: 221 times

Last updated: Aug 26 '17