This is what I've done to my Dagu Rover 5!

As it comes out of the box.

I was shipped the 4 motor version.

I live out here in the "boonies", so I get to talk to guys that use and maintain earth moving equipment.

There is even a guy that restores old tractors, stationary engines and such.

Talking with them was great, they all said powering a track at BOTH ends was a total waste of time and power.

Most people who get one of these say the tracks are a pain.

The 'dozer mechanic, who is ex-army and worked on tanks, told me that I could expect the thing to "throw" tracks due to

- no road wheels

- being powered at both ends of the track

So I went with the Dagu Wild Thumper wheels, 120mm in diameter.

Straight up it draws less current, that might be due to more mechanical advantage of a larger diameter wheel.

One thing that I don't get is most guys just wedge an Arduino etc and a few batteries in the chassis and call it "done".

Well that's just not good enough!!

I want mine to be a lot more robust.

The other thing is if you have off road wheels, the damn thing should be able to cope with dirt, dust and a bit of water!

So I set about building some chassis mods.

The Controller is a genuine Arduino Mega, with Sparkfun XBee, GPS and Monster Motor Shields.

I have a DFRobot prototyping shield with an LSM303 tilt compensated compass sitting on top of the stack.

The XBee is a Series 1, 60mW XBee Pro with the U.FL to RPSMA conector.

My controller is either another genuine Mega with Sparkfun GPS and Joystick shield or you can use an XBee USB Explorer on a computer.

The steering either way looks like a numeric keypad for steering, with "z","x","c","v" setting the throttle level.

My video link is a digital 2.4Ghz security camera, which has a low-ish frame rate, but plays nice with the 2.4Ghz Xbee.

I have a pair of 900Mhz XBee Pro's for when I go to an analogue video link.

Here is some video showing the onboard equipment and some "on patrol" video.

https://www.youtube.com/watch?v=43zqBtQyBF0

https://www.youtube.com/watch?v=iUs2frHb6qk

https://www.youtube.com/watch?v=JIyQP_YWDto

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Comment by Thomas J Coyle III on March 11, 2012 at 7:09am

Andrew,

Nice work. Looks good especially the conversion to wheels inplace of the tracks. Are you using skid steering to turn the chassis?

I am presently building a Traxxas Emaxx from new parts purchased off of eBay. I plan to mount a platform on the Emaxx chassis, in place of the truck body, to mount my processor and communication hardware.

Do you plan to make a schematic and code available? It is always nice to see how others have developed code for a UGV to be autonomous. I am presently developing code for a Parallax BS2px that uses a GPS and a compass for naviagation. Attempting to cram all of the code in the BS2px is a challenge, but doable.

Regards,

TCIII

 

Comment by Andrew Helgeson on March 11, 2012 at 9:19am

It has 4 motors, this might have influenced me a bit!

In the video it is being controlled with a 2 channel Sparkfun Monster Motor Shield.

Because it does have any suspension besides the wheels, just like the loader, if one wheel looses contact with the ground or looses traction, it just sits there!

I've gone for 2, 2 channel motor controllers, each wheel has a shaft encoder and I plan to add traction control.

The controller board is an Arduino Mega, 128k of flash, 8k of SRAM.

I'll use another Mega for the sonar "imager" and probably another for the video overlay/OSD.

I've posted the code on the Arduino forum for the basic remote control and I'll start a blog with schematics.

Sometimes another pair of eyes looking over your code will spot something missed or could be done better.

Lately I've been thinking of adding a bucket like the SDK8 in the photos.

I've not seen any discussion here yet of Autonomous Earth Moving, but the idea of telling it to

- dig me a hole of a specified length, breadth and depth

- take some sand from here, put it over there

- make a ramp of a set grade

is kinda intriguing! :-)

I'm not sure how, yet, but as soon as I get the sonar working I'll have a better idea.

Thanks for the interest!

Regards,

Andrew


Admin
Comment by Thomas J Coyle III on March 11, 2012 at 11:08am

Andrew,

Thanks for the update and the info. I will check the Arduino Forum.

Regards,

TCIII

Comment by ANDREUX Jean Paul on February 13, 2013 at 1:09am

Hello,

very nice Rover.

I am just building something like that with a Dagu Rover,  a Pololu TREX Jr car, my DX8 RC and a video Camera.

Want to put big wheels.

Also  questions :

* with tracks it runs at 1 Km/h . What is the speed with this wheels.

*seems a bit hard to get the tracks off the axels, a fear to break something.  : how did you do it ?

*did the axels and motors  work well after some time .

Thanks for info .

Jean Paul

Comment by Andrew Helgeson on February 13, 2013 at 4:02am

It's a lot faster with wheels with better ground clearance.

GPS speed is around 4-5kmh.

The 6 way battery is a joke, you need way more current, each motor has a 2.5A stall current, getting the rover to move at anything less than 40-50% PWM just wont work.

I've gone to dual 2 channel motor drivers and LiPo batteries.

the axles are garbage, I'm going to drill out the wheel adapters and use 4mm bolts.

As the chassis is shipped with the motor arms at their fullest extension it warps the chassis.

Basically it's a good idea, but the implementation is poorly executed, just a bit too flimsy

Andrew

Comment by Siddharth Shivalkar on July 9, 2016 at 8:34pm

hi guys,

just went through this thread and found it very interesting.

i need to know if anyone can help me with the following:

1. DC Motors ( http://robokits.co.in/motors/high-torque-dc-geared-motor-300rpm?cPa...; )

2. Motor Controller ( https://www.sparkfun.com/products/10182 )

3. Ardupilot or Arduino UNO board.

4. RC Receiver ( Flysky or Frsky )

i am going bonkers on how can i integrate the above where the RC Receiver will give input to the Ardupilot/Arduino UNO who in turn will control the motor controllers to drive the motors. remember the motors are DC motors.

help will be really appreciated. thank you in advance... :-)

-sid

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