Everything you need to know about mechatronics is encompassed in the load. This perspective came to me recently while doing research for an upcoming article in Design World. The idea isn’t original, and its probably been suggested before, but it certainly bears repeating.
The word Mechatronics is a construct of mecha- for mechanical and -tronics for electronics. In general, the idea is to recognize the combination of mechanical engineering in the design of the load and actuators used to satisfy a particular requirement with the electronics needed to control and provide power. The “mecha” part is more the “arms and legs” of an application. And when we’re talking about robots and the like, it can literally be arms and legs.
Mechatronics expertise is applied to the creation of advanced prosthetic limbs. New leg designs help patients by providing more tunable response to varying load conditions. Running, for example, puts different requirements on the body than walking. So a prosthetic leg should incorporate dynamic response features that allow the different performance levels.
And this has been the difficulty with talking about the subject. Because we try to consider every field that Mechatronics applies to, creating a lot of ambiguity about what it is. The core is still the combination of mechanical and electrical or electronic engineering, but it could be applied to anything. Even a toaster. How does it know when the toast is done and then release the spring mechanism? How does it know to not latch the spring when the cord is not plugged in? (I’m still confused on that one)
That everything is a function of the load shouldn’t be a surprise. The term starts with Mecha, after all. So the problem solving side of it is a very complex series of interrelated trade-off analysis which are bounded by the mechanical conditions that exist. If the load is an 800 pound roll of paper, there are certain things you can’t do, like accelerate up to full printing speed in a few seconds. On the other hand, if you have a hard disk drive spindle motor, the target acceleration is 2 milliseconds from zero to 7500 RPM.
So its all in the mechanical details. And sometimes the details aren’t explicitly stated. Writing a good specification is very hard to do in some situations. What does standby mode actually consist of? For motion control systems, standby can be very difficult. Is the position feedback system active? If not, then the system has to recover position when it becomes active. This is the primary motivation for absolute encoders, when power is restored, the system doesn’t have to re-home or do something extraordinary to make it to the next position.
What does emergency stop mean? This used to mean cut electrical power to the motor if you went by the National Electrical Code definition. But if the motor is moving, the load is moving and just cutting power isn’t mechanically safe for personnel in proximity to the load.
So its really all in the details. Ask lots of questions during the initial planning phases of your project. Brainstorm with your client or project leader about all the conditions that might be relevant or occur during the operation of the new design. Remember, everything you need to know is encompassed in the load.
Nwachukwu chukwudi praise-God. says
Nice write up,
Really nice.
I need more of this please…