The post: " /Re: [Emc-users] Spindle position, direction and Index with only one channel.// // //On 11/24/2012 5:01 PM, James Boulton wrote:// / > /Has anyone on list used a stepper as an encoder like this: > > http://home.clear.net.nz/pages/joecolquitt/stepper_as_encoder.html > > James// / " got me reconsidering something I thought about some time ago and laid aside because I have the neither the expertise nor the time to investigate it.
What useful information can be extracted from sensing stepper voltage and current responses? Are there useful differences in the waveforms for missing steps? nearly missing steps? If there are, the detection of such events could be quite useful. For many application 1 or 2 missing steps before stopping might be quite acceptable. If one could detect such things, one might be able to work much faster in materials with highly variable hardness/ resistance (e.g. knots in wood). or be able to stop replace a dull tool and finish the job still within acceptable tolerances. Inexpensive sensors and microprocessors might be able to implement the needed feature extraction and pattern recognition at relatively low cost. Has anybody seriously looked at this? Does anyone know of good models of stepper physics that could be used to guess what to look for? Craig ------------------------------------------------------------------------------ Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
