Hi Dave, In school, we used equipment from: http://www.quanser.com/choice.asp Quanser Consulting for Control Systems labs. We had a movable stage similar to what you describe. It used a brushed motor, encoder, and a rack and pinion mechanism. Sean On Wed, Dec 1, 2010 at 5:20 PM, Dave Tweed wrote: > I have a client who wants to do some experiments involving deliberate ant= enna > motion in a GPS-based system. He's done some simulations and likes what h= e > sees, so now it's my job to set up an actual prototype so we can see how = well > it works in practice. > > We have a small box of electronics that includes the GPS antenna and rece= iver > that masses a total of about 0.5 kg. We want to move this box along a > horizontal linear track that's about 300 mm long, with a sinewave motion = that > has a period on the order of 1.0 seconds. This means that we need to be a= ble > to generate a peak velocity of about 0.95 m/s and a peak acceleration of > about 6.0 m/s/s (and a force of about 3 Newtons). > > We also need to know with fairly good timing precision (on the order of 0= ..5 > to 1.0 ms and 0.5 to 1.0 mm) where the box is in its motion cycle. In cas= e it > matters, the motion will likely not be continuous -- instead, the box wil= l sit > most of the time at one end of the track, and on command, will make one t= rip > to the far end and back. > > I've never put together a motion control system before, but based on some > preliminary Googling, I would guess that given these speeds and loads, th= at > a belt-driven stage powered by a stepper motor would be the type of thing= I > should be looking for, along with a high-level motion controller that can= be > programmed with the sinewave profile. > > Secondary considerations are that the unit should be relatively compact -= - > our box of electronics is about 50 x 50 x 125 mm and we don't want someth= ing > that completely dwarfs this. We don't want to spend more than about $1K t= o $2K > on this, but we want to buy as much of it off-the-shelf as possible. This= is > just a one-off for now, but if it works out, we'll want a cost-optimized > solution for a production design. The control interface would preferably = be > RS-232 (with a separate hardware sync signal?), but we can adapt as neede= d. > > Does anyone have any recommendations for vendors for this sort of thing, = or > any other pertinent advice? Thanks in advance. > > -- Dave Tweed > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .