Let's Make Robots!

ScoutBot 1402 (an Outdoor Robot)

Assists Boy Scouts with Camping Activities

ScoutBot 1402 is a Robot Designed to take camping with Boy Scout Troop 1402.

It is a rather large and heavy Robot, it stands about 5 feet tall, and weighs in at about 300 pounds.  In the photo above, it is resting on a mover's dolly, so that it can be easily moved about the garage when not powered up.  I took a new photo of it since I reached the milestone of not having any bare plywood remaining on the frame.  The upper arms and shoulder joints were recently reworked, and could now be painted.

The latest mechanical work involves installing the two motors for what I call "shoulder rotation" of the arms, different from the "shoulder lift" motion using the Drums and Cable.  This means that the only remaining articulations to be motorized are the gripper open/close movements. 

I have also added a VGA video display in the torso that flips out and turns on.  I have also created a "manual control" panel to test the arm's mechanical movements, without the complication of computer control.

The ScoutBot is due to visit a school in about 3 weeks, so I buttoned it back up, and did some testing of WiFi communications for remote joystick control. 

Currently a work in progress, the main focus of construction right now is finishing up the mechanicals.  It does not matter how good your software and electronics are, if you have sloppy and faulty mechanics, the robot will not perform well.  The arms have recently been fit with the motors for the Shoulder Lift and Elbow Rotation movements.  I have posted a YouTube video here: Click Here to Watch a Video of Arm Movement Tests

(on a side note, to make things sound way cooler than they really are, when people ask me what I made the robot out of, I tell them it is constructed from "ply-tanium")

It is a dual tracked, humaniod torso robot.  It's drive train is made from Rexnord 1864 stainless steel table top chain, and is driven by a pair of 24V electric scooter motors.  Even with it's weight, it can move as fast as a person does at a brisk walk.

People ask about the "tank tracks" a lot.  The first set of "bogies" or track suspension did not work out so well, the robot was simpy too heavy for them to withstand the abuse.  I had to completely re-engineer the suspension, which now looks like this:

New Suspension

Click Here to Watch the Tracks Run on a Test Bench;

The Drive Wheels are made from more 3/4 inch ply-tanium circle cut using a router table, and then sandwiched onto a #60 chain sprocket:

Wheelset on Sprocket

Here is a test fitting of the Rexnord Table Top Chain onto the Drive Wheels and Bogies:

Here is a shot of the Drive Train Motors:

Drive Train Motors

The Torso "shoulder" can rotate, and is driven by an 24V old Electric Scooter Motor, and the arms are driven by automobile seat positioning motors, but they are not installed in the main photo.

Here are the belts, pulleys and drive motor for the rotating shoulder:

Rotating Torso Pulleys

Currently, the track drive, upper torso and the head tilt and swivel now have computer interfaces (although I think I just fried the Pololu SMC board last night for the upper torso, I will have to pull it out and check it over).  Tests on the arms are being conducted under manual control, since the 'bot is large, heavy and potentially dangerous.  The computer control is being done using a conventional PC motherboard, mounted in the lower drive unit.  Since I am a software engineer by profession, I can't wait until we have everything interfaced and ready to go "live" on it's own.  Missing now are motors and controllers for the Left and Right Shoulder Rotation, controllers for the shoulder "lift" and elbow "rotate", controllers for left and right wrist rotation, and linear actuators for left and right claws.

A user named noonv asked to see closer images of the ScoutBot manipulators.  These are fairly primative "claws", the idea being that Boy Scouts in the troop can design and bolt on "new and improved" manipulators as part of earning their Robotics Merit Badge.  As with most of ScoutBot, the manipulators are made from Ply-tanium:

Bare Wood Gripper

The gripper is designed to be rotated at the "wrist" with a gearmotor, and the "claws" close when a cable is pulled through the center axis of the "wrist".  This design allows for full, unlimited 360 degree spinning of the claw without tangles.  The claws are spring tensioned to "open" when the cable is relaxed.  Here they are with more work done on them:

Gripper Closed

Gripper Open

Here is a photo updating the work on the arms, which have been reworked to make use of a "drum/cable" articulation system:

modified arm


The Rotating Shoulder base holds the motors for the cable drive that actuates the Shoulder Lift and Elbow movements.

Shoulder Base

The Robot's main power source is a pair of 12V Wheelchair batteries, wired for 24V:

Battery Pack

The robot is controlled by a conventional PC Motherboard, currently running Windows XP, but I have run the service on both Windows 7 and 8, so I can update the robot later, should I ever feel the need.  Here is the Motherboard Chassis, with modifications to mount in the drive section, positioned right above the battery pack:

PC Motherboard

This is what it looks like mounted in the drive section:

PC In Drive Section

Here is the 24 Volt to PC Power supply, which can run the PC on as little as 12V input:

PC Power Supply

 

I finally have a YouTube account, so you can see some videos here:

Watch the Track Drive Run on a Test Bench

Watch the Head Nod and Shake

Watch the Initial Manual Control Tests

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I'm curious on where you got your e-stop button?  looks exactly like what I want to put on Artie.  I'm calculating in heavy terrain 30A at 12V total, so I need something pretty beefy.

I looked up EMERGENCY STOP BUTTON on Amazon Dot Com. There are many to choose from, and I ended up with this:

E-Stop Button on Amazon

thanks for responding so quickly!

I've found buttons like this on amazon, but most of them only work up to 10A.  How many amps do you find yourself pulling through your system?  My motor controllers are rated at 25A (with a peak of 30), so that's what I'm using as the basis for my calculations.

have you ever had an issue with this switch at high current?

The only issue I ever had with the switch was when the motor controller quit responding, and the robot careened into some lawn furniture, shearing the e-stop button completely off the chassis.

The switch has a rating of 10 amps.  I know under full drive, I am running that or a little more, but here is why I think I do not have an issue:

The robot's computer power supply is the only thing that actually powers up when I close the e-stop switch.  So, there is virtually no "arcing" when the switch closes.The PC does not boot until it is switched on manually, and the primary drive motor controller is on yet another manual switch.

So, I build to higher currents with the switch contacts already closed, so high current arcing does not occur during normal start ups and shut downs.

Since the thing does not run marathons, high current through the switch comes in relatively short bursts, again, with the contacts already closed.

Now, if I had to keep hitting the e-stop while it was running, I would expect the switch to fail in very short order, as the contacts would eventually melt or fuse from repeated arcing.  As it is, I think I can get away with this for some time.

I love the "Keep a safe distance" badge.

I am imagining one kid saying to another "I bet my bot can kick your bot's ass."  ScoutBot looks like a safe bet.

Nice work.  You definitely have serious skills.   Reminds me of a particular "The Young Ones" episode where a guy replaced the motor on a vacuum cleaner with a V8 engine because he thought the original vacuum cleaner was "a bit tentative".

This is really one incredible robot you have going here.  You don't see ones this big very often and it really looks well put together.

Love what you did with the tracks, also the mechanics of the arm mechanism are amazing, its a joy to just watch.

I could see this coming in handy on a camping trip.  Bears in the cooler at 2 AM, what can you do?  Cower in the tents?  Not with Scoutbot 1402 on the job.  300 lbs of lumbering ply-tanium rolling forward on his stainless steel treads.  "You there!  Fur Ball!  Put down that bag of Cheetos or face my robotic FURY!!!!!!"

Love it, thanks for sharing.

This gives me more hope for Groucho. The plan is to use a wheelchair base and a mainly plywood box above that. I have extra wheelchair motors, so I started thinking yesterday of using them for one arm. Then I read about your bot here, and things look more possible.

Your bot is great so far. Are you planning on using ROS?

I am writing the control software myself as a set of Dot Net framework applications using Microsoft Visual Studio 2010/2012.  There are fundamentally 3 software "modules" currently in place:  (1) A remote monitoring and control console application.  (2) An independent video streaming service so a remote operator/manager can check the view from any of the robot's cameras.  (3) The robot control service, which is loaded on boot-up, and does the actual interface and control functions.

As I understand it, ROS is mainly designed for software reuse. This means that if some of the physical things you're doing have been done previously in ROS, then you don't have to redo it. For example there is code for robotic arms complete with Inverse Kineticics so you just initialize the arm code and you just call the code when you want to move the arm. Likewise there is a lot of OpenCV connections in ROS, plus some nice SLAM code and a simulator.

Basically I'm hoping it will make it easier on me to learn the ROS framework than to do everything myself. There is already code to use my laser rangefinders and Kinect so I don't have to write everything from scratch.

In other words, I'm lazy, and it will make it easier to share the code I write with other people.