Friday Night Robotics – Wild Thing

Posted by Erin, the RobotGrrl on Sunday, June 28th, 2009

This actually wasn’t on a Friday (Friday I was making an iPhone app), but rather Saturday.

Since the Sanguino requires too many female headers (which cost money, and I don’t have any), I decided to switch up to the Arduino MEGA. It fits in the box that is already there, so it is all good.

Originally I thought that the Wave Shield would work on the MEGA, but it turned out that it didn’t. What I ended up doing instead, though was using one of the MEGA’s extra Serial lines to send a command to another Arduino to start playing music (on the Wave Shield).

I used my iHome speaker thing that I bought at Walmart for $20. Pretty good value, and it’s purple.

It was pretty fun. However, I only used the motions that I created a while ago when MANOI’s knees were broken. A blog post is coming shortly about the previous FNR where I fixed the gears

I even attached a wild duck to MANOI’s head for the occasion:

Here is a video, it is not too good:

See, the problem in the video (when I had to shake it) was that the TX line to the SSC was loose. It does this from time to time. Especially after switching boards!

Posted in: MANOI, Programming, Projects, Robot.

App on the App Store – Instant Bacon

Posted by Erin, the RobotGrrl on Monday, June 22nd, 2009

The first app I seriously focussed on developing is now in the APP STORE!

You can check it out by searching for Instant Bacon, or clicking here.

Hooray!!!

Posted in: Art, Other, Programming, Projects.

Expelliarmus = Bayes Filter Algorithm

Posted by Erin, the RobotGrrl on Saturday, June 20th, 2009

In the final Harry Potter book, it is mentioned quite often that HP depends on this simple yet extremely functional spell called ‘Expelliarmus’.

I often find myself comparing Expelliarmus in the wizarding world to the Bayes Filter Algorithm in my world. It is such a simple method to give your program a little AI.

Before I go on any further, I just want to say that I didn’t invent the Bayes Filter Algorithm, I found it in this book. It is also said in this powerpoint. Additionally, for good measure, here’s a citation:
The Bayes Filter Algorithm I am using is based on the one in the book Probablistic Robotics. (Thrun, Sebastien, Wolfram Burgard, and Dieter Fox. Probablistic Robotics. Cambridge: The MIT Press, 2006.)
OK, now I think I have all of my bases covered.

So, the Bayes Filter algorithm uses Bayes Law, some initial and conditional probabilities, and the actual probabilities, to give you the final probability.

The first thing that happens is that the prior belief is calculated by adding up the multiplication of the conditional probability table and the initial beliefs.

After that, you add up the multiplication of the probability table and the prior belief.

You then find the normalizer by taking that summation and inversing it.

FINALLY, you can get the final belief when you multiply the normalizer and the number where you multiplied the probability table and the prior belief.

If you want, you can even take it a step further by putting log odds to it based on the final belief and the prior belief.

Here is a class I created in Java (in Processing) that is the Bayes Filter Algorithm:

The Bayes Filter Algorithm is super handy because you can check it by hand. There are no ambiguities introduced into the algorithm. Some of the algorithms, like the Kalman Filter, use covariance in the algorithm to adjust the final belief. This is great, but definitely more tricky to calculate by hand.

I favour the Bayes Filter Algorithm right now because of its ease of use, and it gives me what I want. However, for more interesting results, the Kalman Filter would be a better way to go. If I have time at the end of this project, I’ll probably implement the Kalman Filter and use it instead of the Bayes Filter Algorithm.

Posted in: Programming, Projects.

PechaKucha Night & Multidisciplinary Symposium on Reinforcement Learning

Posted by Erin, the RobotGrrl on Saturday, June 20th, 2009

I gave my talk at PechaKucha night a few days ago. It feels much shorter than 6:40 when you get up there! There was about 300 people, I presented first

I just want to show some pictures of the set up:

It’s really cool. There’s an area there that is separated from the other lounge areas by a curtain. In this area there’s 3 screens. Now, the 3 screens are extremely handy when you’re presenting because you don’t have to turn around completely to know that the slide changed. Also, when you’re looking at the presentation, for some reason it makes it feel more 3D when you see the slides from different angles. Pretty spectacular!

This is what one of the lounge areas looked like:

As you can also see by the screen, this was the 2 year anniversary! Woohoo!

It is also worth noting the efforts I went to to make sure I knew what I was talking about. I practiced an insane amount of times, and I even made an app that shows my slide notes, and I can just swipe through them. (Though, when I got there and decided to look at it, the app crashed just about at slide 10. LOL) But, when I got up there, I completely winged it. The key points were the same, but I have absolutely no recollection of what I said, exactly.

So yeah, PechaKucha was really fun, and the people there were amazing.

Oh yeah: My dad was going to record it so that I could share it with yall, but I forgot the batteries. ROFL! I know right, a roboticist forgot the batteries. Total shame!

The next day I went to McGill for this Multidisciplinary Symposium on Reinforcement Learning.

I had to sit on the floor because there were not enough chairs. I also found the general attitude of some of the presenters was ‘my way, or the highway’.

With that being said, it was all worth it in order to listen to Andrew Ng’s talk (Ng doesn’t have the attitude of ‘my way or the highway’). He was most definitely the only person there that had a great in-depth and practical knowledge of what RL is all about. He was leaps beyond many of the other presenters.

It’s funny though because it felt like the other presenters (who thought that they were all the key to the earth), thought that Ng was using the wrong principles, not RL, in his Little Dog algorithms. They didn’t catch on what it was all about. I lol at them!

In any case, I didn’t go back the next day because I figured I could learn more online and do some of my own research, where I would be learning more.

I like AI & ML more than RL. To me, RL is just AI + ML but in a loop. Long live AI & ML!

Posted in: Art, Other, Projects, School.

PechaKucha Night in Montreal

Posted by Erin, the RobotGrrl on Wednesday, June 17th, 2009

If you’re in Montreal tonight, come be inspired!

I’m giving a talk about my research at PechaKucha night. It’s at La SAT (Société des arts technologiques), starts at 8:00PM and is only $5.

Drop by and say hello!

Posted in: Art, Projects.

Friday Night Robotics – More failures than successes

Posted by Erin, the RobotGrrl on Friday, June 12th, 2009

I think in my entire blog, there’s more stories of failures than successes. That’s cool by me though, because if there wasn’t anything to fail at, there would be nothing to succeed at. Either that, or it just emphasizes the successes. (lol)

So this Friday I tried to make my humanoid draw a happy face. I planned all 36 of the frames out on paper, it was super flawless.

Two hours after I code in the frames and try it, it clearly does not resemble a happy face!!!! >:(

What are some of the problems, I think?:

- I didn’t do the test where I would just draw dots like I thought I would, so my understanding of how well MANOI can draw only extends as far as a rectangle.

- MANOI cannot stand up, I have to hold it upright. The gears were supposed to arrive on Friday! However, RoboSavvy said that it was shipped, but it was not. Hopefully it will be here on Wednesday or something!

- The height of the drawing surface moves, and it’s hard to make it remain constant. I should use a wooden block, however the measurement is unknown at the moment as MANOI is not standing properly because of the knees.

So yeah, all in all, super frustrating!

However, I will be sure to try it again when I get the knees fixed.

In any case, since I’m in the Honors program I get $300 to buy stuff for research! I ordered an Arduino MEGA, two XBees (and two XBee adapter boards). I’m not sure what I will order next…

Check out the LED bling that I set up with the MEGA:

It is a truly awesome controller.

I hope to blog more about my research later on in the week, however it is crucial that I maintain my focus for a little bit longer until I finish off the underlying framework.

Posted in: Art, MANOI, Programming, Projects, Robot.

Social Robotics Research

Posted by Erin, the RobotGrrl on Sunday, June 7th, 2009

Evidently, there was no Friday Night Robotics last week! You might be wondering why…

I’m creating a new method for creating social robots. Currently, the social robots are usually ‘hard-coded’ with beliefs, values, etc.

What I’m researching is a way to create an artificial society with numerous layers of socialization to create this social robot.

I’ll post more details later, but I think this is enough to excite some of the readers who read this feed.

Posted in: Programming, Projects, School.