Contributing to giving sight to AV's

Posted by RoboBill on December 16, 2014 at 9:02am

Hello everyone,

I'm trying to design and build an "open source" radar system. The premise is that while we have the hacked Neato and the RoboPeak system, I've not found anything for outdoor use. So I've built this scanner pictured below.

3691167470?profile=original

The parts list so far is

1) Hobbypower BGM5208-200T-12 HS Brushless Gimbal Motor

2) AlexMos 8 bit controller

3) Arduino Uno

4) Sparkfun Line follower (as a simple rotary encoder)

5) 12vdc power supply

The design criteria is that no special tools (lathe, mill, tap & die) are required. All parts shall be easily available from reputable sources. From this I hope more people will build one and begin to give real sight to their AV.

My question is how to best promote this project and share files like these two versions for the Lightware SF02 and Lidar Light units I made with Solidworks.

3691167506?profile=original3691167374?profile=original

I'm a real NOOB with Github and blogs, so any suggestions would be helpful.

Thanks

RoboBill

   

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Replies

  • Gary McCray May 21, 2015 at 11:53am

    Hi All,

    I just got a LightWare SF30B, their new ultra fast one.

    http://www.lightware.co.za/shop/en/rangefinders-and-altimeters/40-s...

    It is also very small and light at 30 grams.

    My plan is to scan it in X/Y in a GoPro type 3 axis brushless gimbal as well as to use the gimbals built in IMU to provide stabilization.

    Although this should be a great way to produce 3D point clouds, my intention is to mainly use it in a real time path finding and space mapping mode.

    Slewing the rangefinder in X and Y (Pitch and Yaw) using gimbal motors will probably be slower than ideal.

    But I am looking a some interesting solutions for that as well (that don't use slip rings).

    Best,

    Gary

  • RoboBill April 19, 2015 at 4:28pm

    Howdy all, 

    My son has been working on connecting the SF02-32 Hz version to ROS.  Here is a quick pic at the SF02 connected to ROS' RVIZ. More work needed but its getting there.3701985450?profile=original

    Next week we'll try to get the 100 Hz Lidar Lite hooked up to RVIZ.

    One step at a time.

    RoboBill

  • RoboBill March 4, 2015 at 12:51pm

    Hello everyone

    I just received the newest SF02. So I thought I'd compare the two. Below are two scans; 
     

    This pic is my first SF02 with 12 reads per second at 30 degree sweep rate.

    3701948839?profile=original

    This second pic is my newest SF02. It has a REV 3 stamp on the PCB. It reads 32 times per second. The platform is rotating at 90 degrees per second.

    3701948628?profile=original

    RoboBill

  • RoboBill January 29, 2015 at 7:40pm

    Hello everyone,

    Just a quick update... I hookup the Lidar Lite to the Arduino/XBee mounted on the rotating platform. The data rate of transfer appeared to be fine, but the XBee appears to have its own noise problems...oh darn... so I've re-hooked the LL through the slip rings with the I2C scheme. Seems to be OK. The scan below is the LL at 60 degrees per second outside my shop on a sunny mid day.
    3701924806?profile=original

    3701924801?profile=original

    I'm looking forward to other designs.

    RoboBill

    • RoboBill > RoboBill January 31, 2015 at 2:27pm

      Another Update

      Here is the results of the Lidar Lite set at 100 Hz with a very fast sweep rate of 180 degrees per second. The blank areas are simply areas out of range. The average distances shown here are about 25 to 30 feet taken mid-day. Weather is another dry and sunny day.

      3702545193?profile=original

    • Phill Scott > RoboBill February 28, 2015 at 8:51am

      Bill - hows it going? I'll have my CNC router next week, so I'm starting to look at what my device might look like.  I've got a few people who are interested in working on this kind of thing.  I think we'll be a while mixing this in with work and life.  Are you looking at integration with the autopilot?

    • RoboBill > Phill Scott February 28, 2015 at 11:11am

      Hi Phill,

      I've been tied up with volunteering and other projects. I did receive the latest SF02 and parts for a better "angular encoder". Both the line follower sensor and photogate are way too sensitive to sunlight. I'm now going to try a magnetic switch and magnet (both from EBay). Figuring out how to easily mount the somewhat fragile glass magnetic switch has taken more time than I initially thought. Some folks suggested using a regular absolute angular encoder. These encoders are very expensive and since the gimbal motor speed is constant, I simple measure the previous time for one revolution to determine the angle of the laser read during the current sweep.

      Once I get the magnetic switch hooked up, I'll take readings for the SF02 v1 and compare it to the newest SF02 v2.

      I'm also very happy that rover programmer Grant Morphett has said that running backwards between waypoints can be done.So I've started designing the docking station for my rover. 

      I'm glad to hear you're stirring up interest. Please share pics when you get your router.

      RoboBill

    • RoboBill > RoboBill January 31, 2015 at 12:33pm

      Howdy All

      The biggest pain for me was figuring out how to control the Gimbal motor. This was my first experience with all this AlexMos stuff. After many days of trial and mostly error, I finally got it to work and now its very easy to code in the degrees per second. I'm usually running 60 to 135 degrees per second. 

      So attached to this post is my latest profile. If anyone has any suggestions for improvements please post.

      While my line follower guessing encoder works, I'm also looking for ways to use the AlexMos IMU as a possibly better absolute encoder. If anyone has any code that can read the degrees from the IMU, please share. 

      RoboBill

      Profile4.profile

    • RoboBill > RoboBill January 29, 2015 at 8:28pm

      And here is a first go-around of the schematic. It's fairly straight forward.

      3702545095?profile=original

This reply was deleted.