High accuracy sensors?
High accuracy sensors?
(OP)
I'm currently in the preliminary design phase of a high accuracy positioning device. I need a position sensor with a resolution equal to or better than .001 inches. Contact is not an issue, but I'd like to consider non-contact options. I've looked around, and found a few things. Ultrasound sensors seem to not be up to the task I am totally new to this, and I have never done any work in electromechanical control systems before. Could someone point me to some useful reference sites, or give me a few pointers? I would greatly appreciate it.





RE: High accuracy sensors?
Consider the first example. If you go 'home', then step away from that reference position, you can enjoy some fine resolution. If on the other hand you are considering the second example, you'll want a more complex decel, reference resolve, index to position, all wrapped in control algorithm.
Tell us more about the characteristics of the 'position' and something about the inertial load you would like to get to the position.
RE: High accuracy sensors?
I suggest you take a look at the Micropulse range of transducers by Balluff. We are using them on a hydraulic servo system and have had excellent results, achieving repeatability of about 0.0015 and good dynamic response. The transducer has a better accuracy specification than we can make use of because we are limited by the hydraulics. We ditched the original RVDT and linkage because it was a pig to set up and had long term drift problems. Both problems are now thankfully in the past.
If you have the patience to set them up, LVDTs are also very good. Take a look at Penny & Giles, for example. There are numerous manufacturers of these transducers.
----------------------------------
If we learn from our mistakes,
I'm getting a great education!
RE: High accuracy sensors?
I have use Baluff sensors as well. Just had a funny story about their sensors. We were using one in a hydraulic cyclinder (new design) and I was trying to prove the pulses on the bench by applying the appropriate supply, etc. They kept failing. I could never get anything out of sensor. After 3 failures (includes waiting for delivery and of course it was a hot project) and everyone questioning my ability to hook this thing up right. I finally figured out that the pigtail connector was being soldered on backwards at the factory. And some of the other pins don't like 12VDC applied to them so it was constantly failing the units. They felt like idiots but after this was resolved it worked like a champ and have had no problems.
One other consideration for the poster is laser sensors. However, we need more info. Range of sensing? What are we trying to determine the position of? etc.
RE: High accuracy sensors?
<nbucska@pcperipherals DOT com> subj: eng-tips
RE: High accuracy sensors?
Thanks a ton already, you guys have given me material for a hundred google searches so far.
RE: High accuracy sensors?
RE: High accuracy sensors?
RE: High accuracy sensors?
RE: High accuracy sensors?
What type of transport/transmission will you be using to place the object?.