http://www.controleng.com/arti...or_id%23&source=link

Good Job Peter...

For everyone that are curious about whats going on in the mobile hydraulics world of motion control.....here are a few links to some reports about Umeå University research about remote control over internet and "smart" motion control of knuckle boom cranes....


http://www8.tfe.umu.se/forskni...terA1-Uwe_Mettin.pdf

http://www8.tfe.umu.se/forskni...1-Ian_Manchester.pdf

http://www8.tfe.umu.se/forskni...ort_crane_050930.pdf

I know ther was a video clip about this too, I just cant find it just now....

Have fun

Edit
The Umea university of Sweden, co-operates in this project with The forestry division of Komatsu, former Valmet Logging....

This message has been edited. Last edited by: AKKAMAAN,

quote:

Originally posted by AKKAMAAN:
Good Job Peter...

We just sold the motion controller and did a little tech support. The integrator did the work.


http://www8.tfe.umu.se/forskni...ort_crane_050930.pdf
This shows a lot of what I do. I eat this stuff up. Although the basics are same everybody has their own tricks and techniques. I like to see what others are doing and copy the good ideas. This document doesn't go into modeling the supply pressure. My first models were like that but I have found that the details matter.
The model in the pdf considers laminar flow through the valve. I don't but I take into account spool leakage. Spool leakage plays a very important factor in damping when the valve is closed or nearly closed.

Do you understand any of the last document? If so you should join the hydraulic mail list and put a strain on the brain. Right now we are going very slow. We still haven't got to the part were we are simulating the motor induced pressures due to stopping too fast as in Doug Hanson's problem. BTW, in this case torque makes it rotate.

Now for the cool stuff that you should appreciate. Much of our business is in the wood products industry and at a recent Wood Industry show in New Orleans I shot this video of a log scanner that one of our customers uses to scan logs.
http://www.deltamotion.com/pet...Daqota%20Scanner.avi


The difference between the university research and us is that we are providing this technology now for industry. I saw one of Jack Johnson's video about hard to control systems about using an accelerometer and it inspired me to add an acceleration term that allows for damping systems with low natural frequency. Now it is off the shelf technology instead of just research.

This documents/projects are 4 years old...and The project might be post poned due to lack off money...that happens quiet often...

quote:

Do you understand any of the last document? If so you should join the hydraulic mail list and put a strain on the brain. Right now we are going very slow. We still haven't got to the part were we are simulating the motor induced pressures due to stopping too fast as in Doug Hanson's problem. BTW, in this case torque makes it rotate.

I wish I understood it all, but then I also would be hired by the Umea unversity by now..
I appriciate your invitation, I sure would enjuy monitor the discussions on motion control topics....I have learned alot so far...most important experience....there is so much more to learn than I ever thought about before....

I already have a login in on your forum....huvva...

Later....

Also Tampere University of Technology has done something like shown upper. At the references prof? M.Linjama and prof. T.Virvalo has been lectured when I was student. http://www.iha.tut.fi/

Mr Linjama and his group research nowadays digital hydraulics.

quote:

Originally posted by korpirampa:
Also Tampere University of Technology has done something like shown upper. At the references prof? M.Linjama and prof. T.Virvalo has been lectured when I was student. http://www.iha.tut.fi/

Mr Linjama and his group research nowadays digital hydraulics.

Hello "korpirampa"!
Do you speak any Swedish??

Hej då!