|
|
|
Process Control Expert
|
|
Let's look at the two words separately. Process describes a sequence of actions: rising dough, chemicals reacting in a vat, a motor spinning or even evolving biological systems. Typically, though, controlling motors is called motor or motion control and biological systems are another topic altogether. That still leaves processes in quite a variety of applications, including: vacuum and vapor processes in the semiconductor manufacturing industry, furnaces in the steel making industry, pulp bleaching in the paper industry, blending in the food and petrochemical industry, chemical concentrations in the chemical industry and polymerization in the polymer industry. These are just some of the processes that fall under process control, but I think they are enough to give you the idea.
The easiest way to think of control, sometimes called automatic control, is to think of the thermostat in your house. The thermostat controls the temperature. When the temperature gets higher than the desired temperature, the thermostat turns on the air-conditioner. When the temperature gets lower than desired, it turns on the heater. There are a couple of points to note in that action. One is called negative feedback. When the temperature gets too high, the cooler comes on. The converse of that action is positive feedback. If your thermostat turned on the heater when the temperature got too hot, that would be positive feedback. Positive feedback in a control loop typically leads to an undesirable result called a limit cycle. The limit in this case would be the house getting far too hot and you calling a repairman. The other point to note is the on/off action of the thermostat. This is called "bang-bang" control. The heater is either on or off. There is no in-between. Industrial process control typically utilizes continuous control action. Imagine your thermostat turning on the heater part-way (if it could) to gradually warm the room. In the factory, almost all process control will also involve a computer and continuous control, but the analogy with the thermostat is still valid. |
|
|
I have worked extensively with
process control and factory automation and can support your litigation efforts in that
regard as a factory automation or process control expert
witness. My qualifications include numerous peer-reviewed publications
and over thirty years of engineering experience with software,
robotics, instrumentation, process control, computer-controlled
machines and factory automation.
|
|
|
|
Software,
Robotics and Computer Controlled Machines |
|
|
|
|