Accelerating SRR Development While Gyrating Wildly

Decoding the title, I am experimenting with the Phidgets 1042 spatial sensor, also known as an Inertial Measurement Unit (IMU). This IMU contains an accelerometer, a gyroscope, and a compass. The compass is not allowed for competing in the SRR so it is being ignored.

I worked with this IMU for the 2013 SRR but could not get the results needed so I put it aside. Since the first of the year and getting more serious about the 2014 SRR, I began working with it more.

As I did last year, I began working with code I found that would fuse the accelerometer and gyroscope data into a single reading of the global pose of the robot. The results never came out correct. The main problem was the reading for bearing, primarily based on the gyroscope data, was inaccurate. I setup a servo to rotate the IMU through 90 degrees (or a fairly close approximation) but the results usually were less, somewhere in the mid-80 degree range.

After fussing with the code I decided to try a really basic test. First, some background information.

A gyroscope of this nature reports the angular change during a period of time. Specifically, this IMU reports degrees / second and the amount of time between readings. Multiplying the reading by the amount of time tells you the actual rotational movement for that period. Integrating those results provides the current angular position of the IMU. Thus:
\[
\large \theta_{t} = \sum \omega_{t}dt \\
\theta_{t} \text{ is angular movement at time } t  \]

The test is simple. Setup the servo to rotate 90 degrees with the IMU flat. The z axis, up and down, of the gyro should have a rotation of 90 degrees following the equation above.

Revising the SRR Web Material

I have been fighting with fatigue since the June SRR competition. Finally seem to be overcoming it with some medications, better sleep habits, and who knows what else that may be making it better. As a result I am reworking and rethinking the Sample Return Challenge on my website. New material is under 2014 Table of Contents. Pages I am working on have WIP (work in progress) in their title. Comments and suggestions are appreciated here, via email, or on Facebook.

Happy holidays to all of you. May the robot of your desires be under the tree.

Programming Languages Used for SRR

I asked at the SRR Challenge about the languages and vision processing used by each team. Here is what I found:

Team                     Language                       Vision Processing

Intrepid                         C++ / Matlab                                          

Kuukulgur                     C++                                          OpenCV

Mystic                           C++                                          RobotRealm

SpacePride                    RoboRealm state machine          RoboRealm

Survey                           C++, Python                             OpenCV

Middleman                     LabView                                   LabView

UCSC                           C/C++                                      OpenCV

Waterloo                       C++, Python                                            

WPI                              C++                                                             

Wunderkammer             Python                                      ROS vision packages

Here is a rough synopsis of how the teams fared:

Team Intrepid was the first to leave and return to the platform. It thought it picked up the sample but actually did not.

Team Kuukulgur (it means Moon or Lunar Rover), a demonstration team, from Estonia, was the first to pick up the sample but did not make it back to the starting platform. They had the slickest looking robots but then three of the team are mechanical engineers. They brought a swarm of four but one failed so only three took the field.

Team Waterloo, a demonstration team from Canada, also picked up the sample and were the first to return it to the starting platform but the sample was just outside the 1.5 meter square area. It did not hurt them financially since they were a demonstration team and thus ineligible for the NASA money. They did receive $500 from WPI for picking up the sample.

Team Survey won the Phase I competition this year and will take home $6,000 for that effort. ($5,000 from NASA and $1,000 from WPI.)

Team Mystic Lake, myself, did not do that well but I consider it a "building year", to borrow from sports team terminology. Mystic Two traveled the furthest distance of a robot in the SRR to date. It just kept trekking. I proved out much of my code and the ability of my very small rovers to handle the terrain.

SpacePride fielded two rovers but were unable to accomplish much. Their software developer dropped out near the end so they had to scramble to get something working via a state-machine in RoboRealm.

I will update the table if more information becomes available.

Just after I returned from the challenge, an email on a robotics mailing list asked for advice on languages to use for robots. Since I had almost all of the information posted above I put it into a reply and received a nice thanks in return. Hopefully someone will find this interesting.

(Updated UCSC - UC Santa Cruz from comment. Thanks.)
(Updated Middleman aka RoBear from comment. Thanks.)

Linux Sucks

One of the to-do items from the SRR challenge was to learn Linux so I could investigate Robot Operating System and then use OpenCV for vision processing.

Linux does not make this easy and I am rapidly getting frustrated with it as I always do when I try it.

I downloaded and installed Debian Wheezy to get the latest version. It is up and running.

I used the package manger to install Eclipse CDT. Except it is a version of Indigo (3.8) not Juno. Grump, grump, grump. I tried to update Eclipse the other day on another box. There are NO clear instructions on the web on how to do the install over the old version and get it into the menu system.

At the same time I wanted to install Mozilla Thunderbird for email. Nope, not in the package manager and it downloads an archive, not a package. Grump, grump, grump.

Google Chrome downloaded okay and with only one false start I got the package manager to install it.

Even should someone walk me through getting those applications installed I shudder to think of what it is going to take to (1) get ROS and OpenCV setup and (2) get Debian running on all the rover's PCs and running my code.

Rover Names

When I got the 4 computers for the rovers I still had not come up with a good names for them. Loading Windows XP I simply called the first one Mystic One. That led to the others being Two, Three, and Four. The more I used that name I liked it and started referring to them collectively as The Mystics. That is their name now and I will use if for the team name next year: Team Mystic.

The name obviously comes from Mystic Lake Software, my DBA. After Shari and I decided I was retired - I promised to have a warm supper on the table for her every night - I wanted to create a DBA just in case I did pick up some kind of work. Behind our house - and across a street - is a small park with a lake - Mystic Lake. That felt like a good name so I used it by simply adding the "Software". It conveys that aura of mystery that pervades software.

Back from the SRR, links and an EMMY!

Back home after an awesome experience at the 2013 NASA Sample Return Robot Centennial Challenge. I posted on Facebook to capture the activities of myself and the other teams. It was an intense week and with seven days of travel involved getting there and back I am still not ready to jump full speed into much of anything.

If you visit the Mystic Lake FB page take a look at the pages I liked from there. They are either vendors I have used or additional FB pages associated with the SRR. A few of the teams are there. If others have FB pages I am not aware of them.

I do not use Twitter but if you search for #srrbot you can see what was tweeted by others.

The SRR is one of many NASA Centennial Challenges. Challenges of this type have a long history in aerospace. Lindbergh's crossing of the Atlantic is probably the one most well known. He won $33,000 for meeting the challenge.

Worcester Polytechnic Institute hosted the challenge. They were very good hosts providing 3 meals each day so the teams could work continuously. That also provided an opportunity to talk with some of the other teams. At all the other times the teams were heads-down working on their robots.

Friday local school kids visited, saw NASA exhibits, the teams demonstrating robots, and were generally exposed to technology. A group of high visibility social media users also toured the robot pits to talk with the teams and see the robots.

On Saturday, NASA and WPI hosted Touch Tomorrow to showcase NASA and robotics. All the teams demonstrated their robots at times throughout the day. The crowds, and especially the kids, liked seeing the robots perform.

All through the week NASA360 was there talking with us and taking pictures and videos. They were a great bunch of guys to have poking their lenses at us. There are some terrific photos and videos. To cap it off, NASA360 won an emmy for their TV show about last year's SRR: Robots, Rocks and Rovers. In May they won a Telly award for the same episode.

Here are some links to photos and videos:
https://pictures.lytro.com/NASAHQPHOTO/pictures/658265
NASA photos from all days.

(Tom had way too much fun putting shots of the Mystics in trouble in these.)
NASA360 Rover Madness
NASA360 Kicking 'Bot

Video from Mystic Two - taken from the camera on the rover.
Photos of the other teams.
Photos of us and the Mystics (pending getting them organized.)

Still Alive and Working Hard

Long time without posting because I have been focusing entirely on preparing the swarm for the challenge. At some point I do blog entries on the thoughts and activities that went into the project. I will backfill them  just to keep the timing straight.

I have received a lot of assistance from vendors. Some in discounts and some in sharing knowledge. One I want to specifically mention is David Gray of ProgressiveRC. David answered a lot of questions about batteries and the wiring I will need which was very helpful. ProgressiveRC is providing a very nicely cased set of chargers  - the Double Sidekick Ticket - for the batteries, and special ordered 10.4 Ah batteries. There will be two of those in each member of the swarm.

Pololu provided discounts on a Simple Motor Controllers, Maestros, Wild Thumper 6WD, and other parts and pieces.

The last part of the puzzle is picking up the samples. I have the design concept and it works. I even have a video. I have a kludge for this on the current robot but it is pretty ugly. Looking at using tilt mechanisms from ServoCity. Might also need to use some of their construction beams.

I just looked at the hit rate for this blog and it is doing better than I thought. There are 25,000 or so hits. It would probably be a lot better if I were keeping it current but I am awfully busy with the project itself.