P e n d u b o t

Official diary of the Pendubot Team

First steps

Once upon a time, 5 very brave students decided to hunt the wildest animal ever: The Pendubot. Everything began with a dinner on Thursday, March 16th. As expected, Swedes were right on time, French were a little bit late (but not so much!!! ). the first impression was really good: a fun team for a fun project with a fun supervisor. What could we expect more ???

The following day, we have our first meeting with Pablo and the Pendubot. After this meeting, we decide that it is not worth starting right now. We had better enjoy our last weekend of freedom before the real work begins...

First week : it's time to work !!

Monday, March 20th

It's time for our first contact with LabView. When Jenny explained it, it looked very easy. When we, poor students, tried it we understood why we had never used it before. It was harder than expected!!

After sitting in one room during one day for this presentation, we just talked a little bit to decide what we would do the day after and went back home with a lot of physical equations already in mind....

Tuesday, March 21th

When we arrived this day, the Pendubot was (finally!) there, waiting for us. It was our first contact with it (to understand how we felt you have to imagine a kid receiving a present for christmas).
This day, things went really fast. The physical model was ready and validated with the help of our great friend Simulink, LabView was (almost) mastered by Jacob: really impressive !

Wednesday, March 22th

Clock Meeting at 9.00am : let's go for another long day!
This was a really important day : we communicated for the first time with the primitive animal... after some hours of practice, we were even able to make it move (even if it remained quite wild at the beginning!). At the same time, the controllers were implemented and tested with Matlab: a great success!

Thursday, March 23th

It's time to work on the swing-up control.

Friday, March 24th

We validate our swing-up control on Simulink. It seems to work. but the test on the pendubot will be more tricky!

Second week : First problems !

Monday, March 27th

It's time to start the simulations on the pendubot. We managed to stabilize the down up position for the first time. Some drifting error remains but it's a good start!

Tuesday, March 28th

First tests on the up-up equilibrium...and first funny results! The outer link is stabilized in a vertical position but the inner link is dancing when we push the button. But at least the system is stable!

Wenesday, March 29th

First test on the down-up equilibrium. First big problem ! The pendubot drifs, and the controller seems not robust... We have a mistake, but where ?

Thursday, March 30th

What's wrong ? The controllers work on Matlab, so apparently it's not a problem of control design. Maybe it's the model ? We check the model. Here is the problem !!! It works now. Greaaatt !!!Unfortunately we still have a problem. A little offset remains ! It should be a problem in the pendubot. So we ask pablo for the documentation of the black box.

Friday, March 31st

We now know why there is an offset. 10:00 AM ->It's time to meet Pablo. Nothing special during the meeting. Our new objective :try to simulate the down-up to up-up. It's a big step !!!

Third week : some problems, some solutions !

Monday, April 3rd

10.00 AM : the controllers don't want to work anymore! A long day is coming...
A little while later : the controllers finally want to work... sweet !!!
At the same time, the report is being started.

Tuesday, April 4th

We have some problems : we can make two controllers work at the same time. But when we want to try all the controllers, it doesn't work any more!
At the same time, we start to implement the swing-up controllers. First tests on the Pendubot...the cable is too weak!!!

Wednesday, April 5th

Big depression... we don't understand why the controllers don't want to work all together. We thus decide to concentrate on something that works : we write the midterm report! At least, we have no problem with it...

At the end of the day, a new idea shows up : maybe the calculations in Labview take too much time, and that could be why we don't manage to control the system

Thursday, April 6th

Our idea is confirmed : the system is too slow. We have to optimize it

Friday, April 7th

The system is much faster now...sweeeeeeeeeeeet !!

Today was the day for the midterm presentations. Things went quite well (good sandwiches and sodas...). There is no big problem with the project.

Fourth week : Easter break

After three weeks of hard work, French people are exhausted : they decide that it's time for a week off !! As for the Swedish vikings, nobody can stop them. They still want to work on the Pendubot. They will take a break later. During this Easter week, they achieved a great job: the two swing-up are now implemented and work very well, as well as the safety-net!!

Fifth week : The end is coming...

The end is quite close now. The Pendubot is working well, the requirements are fullfilled. The peripheral movement was completed on Tuesday. We just have to celebrate!

Some problems appeared due to the fact that the cable was not insolated. We replaced it with a shielded cable to get rid of that. At the same time we finished the poster and started to complete the final report. We are almost done now.

Sixth week : Some new tasks

The project is almost done now. We still have some problems with the executable file we are supposed to create, but nothing really important. We now have a new mission. Maglev team decided to start a war against us by showing some video on the internet... We thus had to come up with a revenge : look at the useful links ;-)

Seventh and eighth week : the end

The end has come. Things went well during the final presentation. We had a global view of what all the other teams had done: all the projects seemed to work well. We just have a couple of things to adapt in the final report but nothing really important. It is now time to celebrate the end and to close this diary.


Copyright "KTH Corporation" 2006