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.
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.
I'm a real NOOB with Github and blogs, so any suggestions would be helpful.
I just got a LightWare SF30B, their new ultra fast one.
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).
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.
Next week we'll try to get the 100 Hz Lidar Lite hooked up to RVIZ.
One step at a time.
Looks great. Love to see progress like this!
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.
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.
I'm looking forward to other designs.
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.
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?
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.
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.
And here is a first go-around of the schematic. It's fairly straight forward.