My New Year’s resolution for 2013: Make Better Motion. It’s always been part of my makeup when doing motion control projects. Come up with the most cost effective, highest performing and, whenever possible, most innovative solution possible. Not innovation for it’s own sake, but innovation that adds value to the customer’s business. Reduce scrap parts cost, increase throughput, eliminate set up and tear down costs. These features add value to the manufacturing process.
Motion Control (capital M capital C) is about the work statement. The proposed system must produce so many parts in a determined period of time and with defined accuracy. These kinds of statements are well understood, but only scratch the surface of the real needs of the system under consideration. To do better motion requires more insight.
Where does that insight come from? The work statement can be more specific to the mechanical work being done, such as; lift 550 pounds one foot in one second. Also known as the definition of the unit of work, the horsepower. This aspect of the load definition focuses on the purely mechanical aspect of the load requirement. Mechanical loads are also defined by the RPM, starting and stopping conditions and the environment in which the load must operate.
Environmental constraints, even relatively simple things like -40 degree Farenheit ambient, tend to push the limits of bearings and lubrication systems and will cause a lot of failures if not properly anticipated. Washdown requirements in the food industry have resulted in a wave of new products with stainless steel surfaces and some with particular attention to smooth exterior surface that will not accumulate contaminants. Oil and Gas requirements for no open arcing contacts and explosion proof equipment are all examples of the extremes that the motion control industry must address on a regular basis.
Cost is one of the most important aspects of motion control systems. Since the system is made up of a number of components, there are all the individual component selection criteria and costs to consider. There are also a complex array of tradeoffs as well. The motor and drive electronics are considered as a package, the control system requirement is it’s own element, and the mechanism connecting to the load is the last. Is there a return on investment for using a closed loop control system and a second, or axis-and-a-half, encoder?
Often there is important information in understanding the business situation. Is the company engaged in the design of machinery for in-plant use or looking to buy an off-the-shelf solution? I have found that custom engineered solutions generally have better ROI than taking an existing piece of machinery and force fitting it to perform a specific task. Does the company have electrical panel fabrication capability, or even if they do, is there enough bandwidth to support the requirement. Delivering a custom panel built to specification may be a greater value when the company cannot add the labor for a unique requirement that only comes up once in a while.
How we best implement the solution is somewhat more art than science. There are definitely engineering elements to it, but coming through the investigative process and finding unique attributes to enhance performance is a process. All focused on doing better motion.