MNR2.0

Okay, I took my working list of changes in MNR1 and applied almost all of them in MNR2.0. The only thing I did not fix was the orientation of the NXT Brick. I left it flat in MNR2.0. The tracked base was very successful in this version and I plan on diagramming the track layout in a LDraw and perhaps build up some instructions for building it again later when I need that type of base. I have had one problem with the tracked base since the very first use, it does not track straight. I'm going to try some program tweaks to try and improve it. In the current version it deviates 10-15 degrees in 5 feet.

I moved the third motor out of the drive cluster and made it drive a sensor platform. I used a very simple gear system to turn the ultrasonic sensor left and right 90 degrees after the sensor has stopped the robot's forward motion. As with most gear driven platforms I've tried there are problems with gear slippage and accuracy on the turns. I need to work on this somewhat.

Alright, with the changes from version 1 to 2.0 I think I have made good progress. I have a more stable system that rotates the sensors not the entire robot. The tracks are more stable but still do not travel straight. I did buy the Mayan Adventure book and I am reading the first part now. It uses the NXT-G system that comes with the NXT. I'm going to try resetting back to the original firmware and give that system another try. I like the Java kernel but I'm not sure the innacuracies in the tracks are not caused by the motor classes.

2.1 plans:

1. Target the sensor cluster and replace/simplify it.

2. Get the brick up out of horizontal position.

3. Try the NXT-G IDE.

Maze Navigating Robot 1

I've put the card dealing robot on the back burner for a while. I am trying to make a robot that can navigate a maze. I'm going to research and try sensors from both LEGO and other manufacturers to make a robust robot. This line of robots will be the MNR series. I started with MNR 1.

As you can see, I am using a tracked design instead of wheels in either the 4 wheel, 6 wheel or 3 wheel designs. I might revisit this in the future, but I made this decision because the three wheel designs were very unstable and I wanted stability. With MNR1 I had problems with the tracks pulling to the left or the right. I belive it has something to do with the wheel base calculation required for the combine motor control in Lejos. The pilot object will drive the two tracks as a single unit handling the turns and the forward/backward for me, but I have to get the calculations right. In addition I had problems with the tracks bending away from the frame because of track tension.

I used a touch sensor with a probe on the end to determine when the robot should stop and I used the light sensor to check intensity to the left and right on a stop . These sensors were mounted on the center line of the body. I had problems with this design because the touch sensor was too high and missed low objects. I also disliked the way the whole robot had to turn to determine which way to go next. I will use the ultrasonic sensor next time.

Overall this was an interesting starting point. I learned a lot from this version.
1. I want a better tracked platform. I want to focus on making the motor and tracks configuration better.
2. I want to seperate the sensor bed motor from the cluster of motors.
3. I want to try the ultrasonic sensor for stop position control.
4. I want the sensors to rotate not the robot.
5. The NXT Brick needs to be angled better to improve connection to the PC.

I'm going to review more sensor options and look at the book out by APress on navigating mazes using the NXT. I believe it is called The Myan Adventure. It looks like a good resource.

New project

It's been a while since I've had a chance to either write here or do any robotics experimenting.
I bought a new book that has sparked some interest again and I have my eye on another one or two.

I bought Extreme NXT: Extending the LEGO Mindstorms NXT to the Next Level and I have really enjoyed the read.

http://www.amazon.com/Extreme-NXT-Extending-Mindstorms-Technology/dp/1590598180/ref=pd_bbs_sr_5/103-1587592-0151816?ie=UTF8&s=books&qid=1177258983&sr=8-5

It is well formatted and although it deals with very technical things it keeps the focus on the goal. I still need a better understanding of electronics but this books started my thinking process again. I came up with an idea for a project I can try that will challenge my current skill set but keep me close to the foundation I am familiar with.

I'm going to make a robot card dealer. Initially I want it to deal to a fixed set of players. Later I may try to make it player aware using sensors. When I get it working well I may try different games that require dealer interaction.

Over the past few days I think I have come up with a basic design. I'm going to use the robot arm base to provide the rotation and possibly the motor control of the dealer arm. I'm still trying to decide what to use as the feed. It needs to quickly propel a single card forward. Initially I thought a wheel might work but I'm not sure yet. I'm still experimenting.

I've already been working out the deck holder and mating it with the delivery system. I think that will be the hardest part. While I'm tinkering with it, I'm also going to investigate some other programming tools to see how I can expand the basic tool kit. I like the block based Lab View system, but I am a programmer and I often think better looking at lines of code rather than logical blocks. I've not decided that there is a better tool yet. I need to write some more complex programs before I make any decisions.

I'll post pictures/videos here throughout the process so you can share in the joys of success and the agony of defeat.

Education update

I've been out of college for twelve years. I've worked in my field since I walked out of graduation (Actually, I was working the last semester). I've gone back to school on occasion to add a foundation in a new language that I needed. In that process I have learned that I would have a hard time going back to college. The pace is too slow for me. By the end of the first two weeks I'm ready to be done with the course. Most professional training courses are taught in a one to two week format and cover a lot of material in a short time. I guess I've grown accustomed to learning rapidly on my feet. So when I looked at how to add an understanding of everything electrical and electronic to my skill set I chose the home learning route.

Now I have tried this route several times and I have used several texts. I have come to another understanding that I am refusing to accept. I have some kind of mental block when it comes to electrons and how they travel through a circuit. I'm not going to let this beat me. I am on the third chapter of a very large book that is supposed to cover everything I need to know. I already know better than to believe that, but it is certainly setting the foundation.

I have not completely given up on the idea of going back to college for an intro to Electronics but I'm going to see where this takes me. Luckily the Mindstorms kit does not require me to know anything about electronics. I have completed the first two kits. I'm progressing slowly as time allows. The kits advance in difficulty culminating in the NXT Rex bipedal robot. It has the highest difficulty rating and appears to have a rather complex program. I am not going to skip to it yet though. I want to try and control my impatience and spend my time learning the basics. A good foundation makes for a strong building.

Well, here we go.

For those of you who are old pro's at blogging, I'm sorry. I'll get better as time goes by. Not all of my posts are guaranteed to be about robotics, I may ramble on about anything but I am going to try to keep this blog on topic.

This Christmas my wife of almost 11 years bought me a gift that I am very excited about. It will likely provide me hours of entertainment, learning and frustration. It is also likely the fastest way for me to realize a dream of mine. I have wanted to build robots. AI has always interested me, and, until I had a taste of it at work, building an automated machine with a team of electrical and mechanical engineers, I never knew what I had been missing. Since then all of the programming I have done seems flat and missing something.

I am in the process of building through the introductory sets that are provided with the kit to familiarize myself with what I can do. At the same time I am re-igniting the flame that I had extinguished so long ago when the project was over and I had no hope of another project like it (not because of my performance but because the company eliminated the R&D group I worked with and I left for a while to see what the world looked like somewhere else.) I have tried this path once before and slammed into a wall that I have never been able to overcome. I have no idea how to build anything but the simplest electrical circuit. Although I have the desire to build complex systems I can barely read an electrical schematic. This is what stopped my forward progress when I bought my BASIC Stamp last year. It has stopped me every time I have tried. I'm hoping this will not be the case this time. Ultimately I want to build my own sensors and even incorporate other microprocessors in my projects.

I am not able to sleep tonight so I am creating a blog to invite you all into my small downstairs office where I hope to make some robots. Welcome. Your comments are welcome and advice is always appreciated. If you see somewhere that I can improve or somewhere I should research please feel free to comment.