Tuesday, November 30, 2010

Dr. David Dornfeld's "Drinking From A Fire Hose"

Dr. David Dornfeld, Professor of Mechanical Engineering; Director, Laboratory for Manufacturing and Sustainability at University of California, has written two excellent articles:

                Drinking From A Fire Hose
                Drinking From A Fire Hose: Data Collection  Part II

Below is a great example of Dr. Dornfeld quantifying energy values in a medium facility:
"Recall that we had estimated that sampling energy data values for a “medium sized facility” for a day (here meaning 25 CNC machines, 10 programmable logic controlled machines and assorted other handling and line equipment with 8 data sources per machine at a sample rate of 5 hertz) would yield a data stream of 86,400,000 data points each day. And that if we added the other sources, we’d likely end up with 100 million data values a day to deal with.
Below Dr. Dornfeld discusses the importance of correlation:

So, let’s continue our discussion from last time. Data can be related to events and information associated with those events. Thus, data can be understood as something that occurred either at a specific time or over a range of time. In manufacturing systems, events can be a numerical value (for example, the instantaneous power consumption at a specific time) or can be a type of annotation (for example, the alarm state of the machine tool over an interval). Complex events are abstractions of events that are created by combining simple events. For example, based on simple events pertaining to the tool position, the instantaneous power consumption, and the machine tool’s program in machining a part, we can create maps linking power and stages of part production"
Dr. Dornfeld is an internationally known expert and one of the creators of the MTConnect protocol as well.  Dr. Dornfeld is also known for Dornfeld's Law.

No comments:

Post a Comment