Control Considerations in Mechatronics

PAC hardware can be used in multiple domains, including logic, motion, drives, and process control. And the software programs all control and monitoring tasks of multiple domains. This feature enables the programs to “flow” as the requirements of the application dictate.

Critical to any mechatronics system is the control. One of the newest controllers is the programmable automation controller. Here are tips on selecting one for your specific application.

By Kelly Downey,
Electrical Engineer
Opto 22

Industrial applications continue to increase in complexity, requiring controls that can integrate multiple systems that incorporate discrete, motion control, and process tasks and that can gather, process, and transmit real time data to company databases. Programmable automation controllers (PACs) can be one choice for managing this complexity because they combine the capabilities of several traditional control and monitoring systems. Typically, they have features found in programmable logic controllers (PLCs), distributed control systems (DCSs),remote terminal units (RTUs), and personal computers (PCs).
Even so, control manufacturers offer PACs with varying capabilities. Thus, there are several considerations to keep in mind with your selection. Read more

Networks and Control

Network technology has changed dramatically. Speeds that would have seemed unimaginable ten years ago are off-the-shelf these days. And with the speed a lot of bottlenecks have disappeared. With the possible exception of motion control applications.

Networks for motion are still a in category by themselves. Sercos has gone through major evolution to its current level, Sercos III, to continue to hold its position as the top performing motion network. Other implementations of Ethernet, EtherCat, Powerlink and others bring the high bandwidth available in Ethernet and add features to the network to insure its performance for motion control applications.

But the network technology momentum continues. There is a specification from IEEE, 1588 Protocol, which adds hard real time to Ethernet by clocking to make sure that messages get where they are supposed to be WHEN they are supposed to be there. This feature creates a level of determinism that has long been a stumbling block to more broad acceptance of Ethernet in the industrial community, possibly eliminating any serious impediment to using Ethernet for motion.

The controversy is usually around the question of “What is Real Time?” How fast is fast? Well, its usually whatever is fast enough for your specific application. But that doesn’t really help control system manufacturers when developing solutions for a broad audience. So its nice to find that the technology migration is starting to resolve some of the basic issues with respect to motion control, with something more broad than a vendor specific solution.

Even the Open DeviceNet Vendors Association seems to be exploring the potential of IEEE 1588 as their Common Industrial Protocol as a platform for bringing the legacy networks of manufacturers together as an overall solution. This is a very significant effort, one that has been difficult to achieve, that many users need help with. Operating a manufacturing or process plant is hard enough without having 3 or 4 different networks to maintain, and worse still, exchange information across different platforms.

My guess is the cost pressure of inexpensive Ethernet components will continue to push manufacturers toward finding similar solutions. But is sure would bring everyone along more quickly if the competition among control system providers were balanced with an option that everyone can find acceptable. IEEE 1588 is certainly a possibility worth considering.

Motion and Communication

I used advise people working on motion control never to make a communications layer part of the application. There were too many things that could adversely impact the motion. But communications have gotten a lot faster, and there is a tendency to think of speed as the issue. Not really.

Motion Networks are a breed apart, Sercos, Firewire, USB and many proprietary solutions are offered in today’s marketplace. Claims are made about, not surprisingly, speed. And determinism. That’s the tricky part. Guarantee the message got there when it was supposed to.

And its kind of the same problem for PLC’s doing motion control. Yes, its true that most applications do not require tight coordination between two or more axes. So its perfectly reasonable to put the motion in the PLC and let it referee when independent motion axes start. It leads to the assumption that everything is fine no matter how many axes and if any are coordinated, synchronized or registered to a moving target. Read more

The Continuing Evolution of Mechatronics

It began as the integration of mechanisms with electronics. Since then, mechatronics has evolved, and for all practical purposes, includes nearly every engineering discipline.

By Andy Urda, Director Channel & Industry Marketing

Yaskawa Electric

In 1953, Yaskawa Electric began its active role in advancing technology in the field of motion control when the company introduced its servo motor line, the Minertia® Motor (named for minimum inertia). These servomotors made rotation exact to the proportion of conduction. Due to their very low inertia, they handle extremely fast starts and stops. Originally, they were applied to electrical actuators for the control of mechanical arms. Today, they are also found in many industrial automation applications. Yaskawa’s signature phrase of the late 1960’s and early 1970’s was “Mochintrol,” which was created from the combination of motor, machine, and control. Mochintrol became a registered trademark for the company in 1971. Read more