Friday, November 30, 2007

Parts Arrived!

We're finally starting to get our massive quantity of various components from our various vendors. Many thanks to all the help from our company contacts who were able to offer us educational discounts for this project.

We received the wheels and rims today, we got extremely lucky that these wheels came on the market when they did. Apparently this is the first cast aluminum ATV rim in production and it has only been available for a year. This saved us from machining our own rims, saving us $1500 and two weeks of shop time.

It's finally starting to hit us that we'll be assembling this robot at the beginning of January and we're all excited to get out of the doldrums and into the fun part.

Wheels



Drive axle being machined on the CNC lathe

Sunday, November 25, 2007

Sponsorship

Ken Corcoran from Geophysical Survey Systems Inc. generously offered us a SIR-3000 Radar unit that we'll use while testing and developing the interface between the robot and radar control electronics.

The whole team will be heading down to the company headquarters in Salem in January to give a presentation on the project and learn about GPR from their engineers.

The team is excited about partnering with GSSI and we'll keep the updates coming as we figure out more.


SIR-3000

You can find more info about GSSI or the radar we're using from their website:
GSSI
SIR-3000 info

Friday, November 23, 2007

Turkey Summary

At present, most members of the group are probably sleeping off a Turkey Coma from yesterday's feast, and resting up for the last push at the end of the Fall Term. Yet, the end of the Holiday is just around the corner so the purpose of this blog is to summarize our plans for the rest of the term.

Before the break, the group met up to talk about what we felt needed to be done before the end of the term. The group decided that we will finalize mass and money budgets for the robot based on the constraints of the grant and mass allocated in the Graves et al. design. At this point, most big-ticket items are ordered and the masses of most of the significant weight items are known. In order to assure that no surprises in space allocation arise, the group is also planning to build a mock up of the electrical control box to which everyone will add the parts they have been responsible for this term. In this way, the group hopes to anticipate any problems that may arise next term and ensure that parts will not have to be reordered. This is especially important because of the long delivery time associated with many of the ordered parts.

Other tasks we will be working on include the finite element analysis of the passive swing joint in the middle of the robot and addressing the fact that the design for the robot has been done in metric units (and our machine shop prefers English units). A hardware block diagram will be completed and a software diagram sketched out...Finally, the group will need to write a progress report and prepare a presentation for the review board on the term’s progress. All in all, it will be a very busy two weeks!

In the midst of my own tryptophan-induced stupor, thoughts of the robot seem a bit distant, but we are only days away from coming back to campus, and the project. Yet, it’s time (and probably well past time for me) to pull my thoughts back from Christmas and family to the real world.

Friday, November 16, 2007

Communications Parts Pictures

Here are some pictures from the communications systems.


GPS reciever chip: Novatel OEMV-1





Wireless Modems: Maxstream Xtend


A chip like this one in the robot:





and a box like this plugged into my laptop to talk to the robot:




High Gain Antenna:


Thanks for your interest,

Robot Parts Are Expensive

Most of our earliest efforts pertained to finalizing the mechanical design of the robot so that we could begin purchasing and machining parts. I am hoping to get our proposal power point presentation posted to this blog so that everyone can see what we are planning to accomplish.

As it turns out autonomous robots require a whole lot of expensive parts. We have spent the last several weeks searching the internet for parts. The main items are the following:

aluminum rims [wheels] (x4)
snow tires (x4)
electric motors (x4)
motor controllers (x4)

Batteries (x9)
Battery Chargers (x3)

central processing unit
incline and temperature sensors
GPS reciever and antenna
Radio Modem, Tranciever and antenna (x2)

Aluminum stock for machining parts

The majority of these items will be ordered over the course of the next week. I am working on the communications systems: the GPS reciever and the wireless radios. I have included images of them for your browsing pleasure. Hopefully my collegues will see fit to post images of the other parts.

As this post implies these parts are expensive. We have allocated nearly $1000 of our $1400 budget to purchase these items. This however covers all of our big expenses. The remainder of the money can be spent on miscellaneous parts and testing equipment.

Thursday, November 8, 2007

Robot Background

Each year, several Antarctic research expeditions travel across the Antarctic plateau in convoys of truck-sized tracked vehicles called snow cats. The lead vehicle uses carry ground-penetrating radar (GPR) to detect snow-covered crevasses that are invisible from air and pose a substantial hazard to ground vehicles. Snow cats cost around $250,000 and require massive amounts of fuel, an expensive commodity in antarctica.

The pupose of our project is to build an autonomous robot that will replace a snow cat to perform GPR surveys with the goal of crevasse detection.

Our robot will be:
-80% faster than a Pisten Bully snow cat
-28,000% more energy efficient
-1/20th the price
-easier to transport, operate, and service
-safer to operate

Robot Design:




Specs:
Length: 1.14 m
Width: 1m
Height: .57 m
Weight: 60 kg
Speed: 7.2 km/hr
Lifetime: 4.2 hr
Range: 33 km
Min. Operating Temperature: -40 degrees C




Detail of robot design featuring horizontal pivot and symmetric chassis.

Project Introduction

We are a team of six Dartmouth engineering students building a robot to perform ground penetrating radar (GPR) surveys in Antarctica.


The team is composed of

Augusta Niles


Eric Trautmann


Scott Newbry


Drew Branden


Michael Zargam


Kevin Olds



We'll be posting updates and information as the project progresses. Please email me at eman@dartmouth.edu if you have any questions.