[29 posts]
5 years
One of my many projects is a robot I call “The GardenBot”.  I’m building this for my wife, Carol to work around the yard so she will not have to carry heavy tools, dirt, fertilizer, etc.
The concept behind the GardenBot is fairly straight forward; my wife carries her small light-weight garden tools in the bright orange Home Depot bucket. The GardenBot’s computer vision system tracks the bucket and drives the motors to follow it – pulling the garden wagon loaded with heavy gardening materials and tools. The GardenBot will autonomously maintain a 4 foot distance from the bucket and wait until the bucket moves, then start following again.
The prototype was built using a donated robot lawn mower from my good friend, Bill Webb. This is the model RL-500 from Friendly Robotics.  I removed the OEM control board and cutting motors and developed the tracking algorithm to test the software and capabilities. It currently has a Dimension Engineering 2x10 controller (older version), and Asus NetBook running the computer vision software from RoboRealm. This version is about 60 pounds and is safer when testing the software and doesn’t hurt as much when it runs into me. This also incorporates a “pilot” or First-Person-Viewer (PFV) camera mounted above the batteries and long-range 3000 ft. video transmitter.  I have future plans to control this bot up to 4000 feet and mount a big 6 axis ScorBot III robot arm and will christen it the “Cerberus “. Cerberus will autonomously roam the property and track, report, and alert when an unwanted visitor is detected on my property. Oh yeah, It will also go to the mail box and retrieve mail.
The final GardenBot version will be constructed using the tread-based Trac-Drive from a disassembled Craftsman Snow Blower and powerful  electric wheelchair motors, Dimension Engineering Sabertooth 2x60 (dual channel 60 amp) dual motor controller, Pololu 6 channel servo controller, Asus 1Ghz NetBook running the control software, and pan/tilt servos to control the tracking USB camera.  The finished GardenBot is expected to weigh about 200 pounds with two on-board 12volt batteries in series supplying a total of 24volt DC for the power train and system power.  

View it on YouTube: http://www.youtube.com/watch?v=r-ZiGQP2G9s&feature=plcp&context=C408e5e3VDvjVQa1PpcFOeP7biAPuocv5aPc476s96cqKvm_k1XoA%3D
Anonymous 5 years
could you share your robo files with us? Are you using AVMNav plugin?
Anonymous 5 years

Nice video and concept. Can't wait for shopping carts to have the same capability!

Couple suggestions:

1. The 'fish tailing' issue is caused by over compensating on the motor ... ie it overshoots the correct placement which causes it to overshoot on the other side. You can fix this issue in several ways:

a. increase the sense react loop. Check the fps on the pipeline. Sometimes the camera also does not have enough light and will create a very slow frames per second.

b. add a panning servo to the camera and move that instead of the entire robot. It will update quicker and reduce the wavering. Once the pan is past a certain limit you can then move the entire bot in that direction.

c. slow the robot movement

2. You can add an audible alert when the system loses the bucket so your wife will know when the bot has gotten lost.

Keep us updated on your progress!!

 [29 posts] 5 years

I do have a pan/tilt on the camera. When the Pan is past the deadband, it turns the motors to center the COG box. The speed at which the Pan and motors turn is proportional to the direction and delta from COG. I think I need to widen my pan-deadband proportional to distance before turning the motors. There is a lot of orange at Home Depot so it was a challenge to adjust the Color Filter Module to eliminate distant orange objects and reflections. Any suggestions on other filters? I placed and paper tube around the web cam to narrow the field of view (FOV) and help to control background lighting changes.

My Frame Rate is around 13-15FPS and is good.

I also have speech output to announce the bot movements and vision status; "move the bucket left please", "move the bucket right", "forward", "Back", "wait up!".

I tried the object recognition module but it was very slow.

I had a problem with having voice and trying to play wav files. The voice was choppy and delayed when wav module was present, so I stuck with voice only.

I will attach the .robo file later today.

Thanks again.

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