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• Autonomous robot moving with Open Simple Lidar

  iliasam • 04/17/2018 at 19:21 • 0 comments

  I write a special simple navigation node for the ROS called "simple_nav".

  Here is a video of robot autonomous moving to the given goal point:

• Interference filter

  iliasam • 04/10/2018 at 18:45 • 0 comments

  I'm using interference filter in my lidar: https://en.wikipedia.org/wiki/Interference_filter

  It is used to decrease ambient light from different sources.

  Here is example of filter working:

  The left picture show influence of the lamp light (it is placed to the floor) to the Lidar image. Right picture was captured with filter installed.

• Updated PCB

  iliasam • 03/04/2018 at 16:42 • 0 comments

  I have updated PCB of the Open Simple Lidar.

  I have routed and placed small motor board together with the main PCB of the lidar. Earlier that motor PCB must be produced separately, but now only one common PCB in needed to be produced.  Motor board must be cut from the main PCB before assembling the main PCB.

  Also I draw some descriptions for assembling PCB.  

  New PCB image (motor PCB is on the left):  

  Updated files: https://github.com/iliasam/OpenSimpleLidar/tree/master/PCB

• Testing Lidar with ROS

  iliasam • 09/19/2017 at 18:44 • 0 comments

  I had instlled my Open Simple Lidar to the old Roomba and tested it with ROS (including Hector SLAM):

  Photo of the lidar installed at the Roomba:
  

  
  

  The left board is Orange Pi PC running ROS nodes (Lidar node, Roomba node, Hector SLAM).
  All robot controlling was manual (using keyboard).

  The resulting map of the rooms:

  
  

  This map was created with lidar working at 2 deg angular resolution mode.

  Also I have published Firmware code and lidar ROS node at Github.

  Next step is increasing parameters of Lidar by optimizing  it's firmware.

• Open Simple LIDAR is fully assembled!

  iliasam • 09/11/2017 at 19:14 • 0 comments

  Here is the photo of the assembled LIDAR:

  Last thing that I had installed is the small PCB with DC-DC converter for powering  motor.
  Photo of the installed board:

  This board also simplifies connections between LIDAR's components.

  Photo with the scanning head installed:

  Front view of the assembled LIDAR:

  My next step - write a node for ROS and to test SLAM algorithm.

• First tests of my Lidar

  iliasam • 08/31/2017 at 11:47 • 0 comments

  I have done with basic firmware for my Lidar.

  There were some problem with encoder signals - UART communication produce some electrical noise at the encoder's line.

  Here is a video of first test:

  I decrease angle resolution to 2 deg to increase rotational speed - it is near 5 rotations per second.
  

  Circles at the "radar" images are 1, 2, 3 m in radius.

• Testing encoder

  iliasam • 08/14/2017 at 18:14 • 0 comments

  I wrote a simple program for testing encoder. It's just blinking led at PCB when there is a hole in encoder disk.

  Photo of LIDAR with big exposure:

• Assembling LIDAR

  iliasam • 08/13/2017 at 15:46 • 0 comments

  Now it is time to final LIDAR assembling.

  I have installed encoder to the "main plate", installed the PCB to the PCB holder, installed slip ring to the PCB holder, solder wires of the slip ring to the PCB pads.
  Photo of the assembled LIDAR:

  Side view:
  
  

  I have tested mechanics of the LIDAR - everything is working fine, the eccentricity of the LIDAR rotating head is not very big.

  Encoder is working fine too - oscilloscope shows  a good signal.

  Next steps are assembling small PCB for motor controlling and programming.

• Assembling LIDAR mechanics

  iliasam • 08/06/2017 at 18:10 • 0 comments

  First step is building "main plate" - it is the part that holds ball bearing, motor, and some other parts. This part can be cut from some flat plastic plate. I have used 5mm acrylic glass:

  
  

  Drilling 42 mm hole for bearing was a little tricky.
  This part can be printed at 3D printer.

  Next step is assembling everything.

  Photos of assembled mechanics (top view):

  
  

  Side view:

  
  

  Motor is connected with the PCB holder with rubber belt.

  Down view:

  
  

  Here it can be seen method of fixing the PCB holder to the ball  bearing.

  Next step is to fix encoder at the "main plate" and to test it.

• PCB holder

  iliasam • 07/30/2017 at 12:31 • 0 comments

  I have printed special holder for PCB. This holder will be rotated by motor.

  Here is a photo of it:

  The right part is encoder disk.

  PCB holder don't have holes for slip ring wires, so I have to drill two.
  Here is a photo of the PCB holder with the slip ring installed in it:
  

  Photo of PCB placed to holder:
  
  

  Encoder disk is glued to the PCB holder.

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