Thursday, December 27, 2007

Grades Are In

Well, the grades are in. Once again I don't care for them. I had a big post where I bitched about them, but I decided I didn't want to post it so I got rid of it. Anyway, bottom line, the grades are in and mediocre as usual. I'm going to change my class schedule for next semester. I'm tired of getting mediocre grades for the effort I apply to it. I'm going to take some easier classes. Hopefully it will leave me more time to post.

Wednesday, December 19, 2007

A Trip Down Memory Lane

Raise your hand if you remember Kenners.

I'm guessing that nobody is raising their hand. You see, when I was kid my dad had these old toys from when he was a kid called Kenners. They were little plastic I-beams and columns that you used to make building and bridges out of. There was also little plastic panels that you could put on your buildings to make them look realistic. Kenners were one of the ways my creative gene was cultivated. They were in good company with an Erector Set and a vast collection of Legos

This year for Christmas my little brother Shaun got me a set of Kenners. He found them on the internet under the name of Bridge Street Toys. I couldn't go to sleep until I had built a bridge out of them. Check it out.

Neat, huh. This is the bridge set and they also have a set for making buildings and another for making some type of hydrology plant. Neat stuff. Here's another pic. The little cement truck didn't come with it, I already had that.

If only I had the time to play with Legos also.

Thursday, December 13, 2007

Controls Test

Well that controls final was a real kick in the shorts. The first problem featured a motor system with a load connected by a compliant shaft (that means it has a little springiness to it) and some damping. Its your standard torsional mass-spring-damper--or is it? Not quite, since the spring and the mass are connected in series instead of parallel it introduces an extra degree of freedom to the system. I could not solve it. After I finished the test I went to a study room and worked the problem over a couple of times. Each time I kept getting three equations with four unknowns. It was really frustrating because I felt like this type of problem is my forte.

The next problem was a root locus. These are not normally that difficult. Dr Minor, however managed to find one that was tricky enough to fool even the brainiacs in the class. (I know because I stayed after to talk about it with them.)

I guess I'll check my grades in a couple of weeks. I doesn't really matter, I know I passed all my classes, we'll just have to see how good I do. Now I have some time to rest my brain for a little while.

Monday, December 10, 2007

Finals are Almost Done!!

Well, today I had my second to last final. I also turned in my design notebook and design report which marks the end of the semester requirements for the first semester of Senior Design. Now all that is left is to take my controls finals tomorrow at 1:00. I'm not too concerned about it, all I have to do is make sure I have all the formulas I need on my sheet.

This semester has been really great. Contrary to what everybody said, it hasn't been much easier that last year. Well, that's not exactly right, it was easier, but still very time consuming. Really, that's only because I'm a glutton for punishment. The classes I'm interested in are the tricky ones. I know there is a future in robotics and effort now will pay off well. Even if I don't work in robotics directly, I really like studying it because it combines all the best parts of mechanical engineering, electrical engineering and computer science.

Here's to nerdliness!

P.S. I've been thinking of buying a vintage slide rule and learning how to use it. Neat, huh.

Friday, December 07, 2007

Robotics Project

This semester has been great. I've been able to take classes that I really enjoy. Since I'm a glutton for punishment the classes I want to take are also very time consuming. My two favorites this semester are called Advanced Controls and Intro to Robotics. They are extremely interesting. Controls deals with properly controlling systems to do what we want, like controlling a motor to move a lever to make the lever get there when you want and as accurately as you want. Another example of a control system is the cruise control in your car. Robotics deals with the math of making a robot go exactly where you want it to. Its a hard problem because you have to make all the individual joint angles add up just right to put the gripper where you want it.

The final project in that class deals with just this problem. The graph below show the trajectory of the end effector. That is, if you were sitting in a chair that the robot was holding in its hand, the blue line on the graph would be like a roller coaster track that you would be riding on. The red line shows the path of a block that we want to pick up with the robot.To make the robot do what we want, we split that blue line into 235 pieces and we have to calculate the joint angles at each of those individual points. Neat, huh. You see, that's why want to make a computer do the math. It would take us days to calculate all those numbers.
Here's a picture of the robot that this program is for. Its called a Puma 560. This picture is from a research lab at Newcastle University. These are really common in industry. Actually, they are becoming obsolete in favor of robots that have much more sophisticated control systems.

Next semester I will be taking the follow on course for Intro to Robotics. It's called Intro to Robotic Control. I know that sounds like almost the same thing, but its not. It will take some of the elements from this class and the controls class I'm also in and build on them. For instance, we will learn force control. Here's an example: Imagine you want the robot to write on the chalk board. You have to be able to control the position of the chalk very precisely while at the same time making sure the robot is putting enough pressure on the chalkboard to make marks. What a trip. Unfortunately the real fun of robotics happens at the graduate level. I'll be back to school sometime.