Design News for Mechanical and Design Engineers

What trends are developing in automation?

Industrial Ethernet is becoming more prevalent in many different flavors in regards to more advanced functionality. What started as a method to connect machines in the office environment via Ethernet has become much more prevalent with machine-to-machine and even controller-to-controller connections. Basically, an entire machine can be wired for Ethernet. We at Bosch Rexroth have an Ethernet strategy supporting several industrial Ethernet varieties out there — but we think the best Ethernet variety is an open bus system called SERCOS III. This network was designed by a team of collaborating companies, including Bosch Rexroth. It's designed from the ground up to handle the highest performance applications for industrial Ethernet.

What sets SERCOS III apart from TCP/IP systems?

Motion control is at a critical level of need, where real-time response is necessary. If you're starting and stopping an axis of motion, you need to control that very precisely. The system needs to reliably move from point A to point B, or there will be process errors. When printing a nice glossy magazine, a registration error is a big deal because you have advertisers depending on accurate presentation. That's a good example of how a small error in motion control can cause a big problem with product quality. With SERCOS III we've taken the network protocol and built it upon a high-speed reliable base. That solves the motion part of the equation. With time that's left over, we do things like I/O handling, diagnostics and production statistics. We've designed it so motion control happens first in the network cycle, so there is always high-precision motion control.

With the SERCOS network, there is intelligence in each device. You only buy exactly what you need. This gives you the highest level of determinism without additional cost. A little intelligence in every module is a much more cost-effective and scaleable solution. Distributed intelligence cuts down on communication time because when intelligence is wired into a drive, it can react faster — a necessity for safe machine solutions.

What systems are meeting the demand for increased floor space?

In every industry from printing to packaging, no matter which machine you get into there are basically two things going on. The first is people are trying to design control cabinets so they're physically connected to the machine. This solves the problem of extra space on the floor and there's no need to disconnect the cabinet when moving or starting up a system. Companies are also coming out with combined solutions — Bosch has a solution where motion and logic are right in the servo drive package. You can stop and start faster and it's all electric — you can do electric gearing without having to adjust mechanically. You can run it right out of the drive — that removes a component right there.

Another really innovative move is to put the servo drive out on the motor. This setup removes the need for heat dissipation or an air conditioner. It also vastly reduces cabling. With Bosch's system, you run a daisy-chain system from machine to machine. This reduces cost and machine layout.

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