Building : 8325


Building / 8325	8324 \| 8326

Subject:	Re: Analogue Control of Pneumatics
Newsgroups:	lugnet.build, lugnet.general, lugnet.technic, lugnet.robotics.rcx
Date:	Thu, 22 Mar 2001 23:34:35 GMT
Viewed:	1360 times

Whoa. Not entirely correct. You can do accurate positioning with pneumatics, it's just harder to do than with hydraulics, because you have to take air compressiblity and seal "stiction" into account if you want to hit an arbitrary position that's in the middle of your cylinder's travel. OK. That said, LEGO(R) pneumatic parts aren't ideal for accurate positioning : ( > > what you ask is not possible because the Lego pneumatic system is, > > precisely, *pneumatic*. In real life cylinders that are designed for > > position control are hydraulic and not pneumatic ones. This difference is > > very important because you can compress a gas but cannot compress a • liquid. > > A pneumatic system has a very high degree of elasticity, and in practical > > terms this means that position is a function of both the applied pressure > > AND the encountered resistance. > > Ok. So you can't do it with pneumatics.

Message has 1 Reply:

		Re: Analogue Control of Pneumatics
Hi I did some 'research' in this area about three years ago for the control of a pneumatic robot arm. It was quite simple positional control ie position the piston at any point in the cylinders stroke and hold it there. The controller was just a PC (...) (23 years ago, 24-Mar-01, to lugnet.build, lugnet.general, lugnet.technic, lugnet.robotics.rcx)

Message is in Reply To:

		Re: Analogue Control of Pneumatics
(...) Ok. So you can't do it with pneumatics. Looking around for alternative ways of making a power steering mechanism, I found this link (URL) which gives an RCX based motor driven mechanism that might be of interest to others. Al Telanco (23 years ago, 22-Mar-01, to lugnet.build, lugnet.general, lugnet.technic, lugnet.robotics.rcx)

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