Electronic Controls

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Throughout 2008, OEM Off-Highway's Fluid Power Series has traveled through the mobile hydraulic system. In the March issue, the hydraulic system was described as a team that requires all members to be on the field in order to achieve success. Fortunately, from a safety standpoint, the team isn't a self-starter. Nothing happens with the cylinder, pump, or motor until it receives an input from the coach in command of the machine. Today, thanks to electronic control technology, communicating with the hydraulics team has never been easier or more effective.

"Electronic components themselves are generally more environmentally hardened than they were 10 years ago," says Dan Ricklefs, product portfolio manager - controls, Sauer-Danfoss, Ames, IA, "but more importantly, systems are being designed in a manner that is simply more robust. Control schemes that address error detection, proactive fault handling, and general machine safety are better understood and more widely employed. Advances in products like graphical displays can now provide significantly more system information to the operator, making the electronic control system less of a 'black box' and more of a benefit to getting the job done. All these advances help instill confidence in electronic control solutions."

Not only has the technology itself evolved, but so has the customer's acceptance and expectation of electronic content inside an off-highway machine.

"From a demographic point of view, most of the end users and engineers coming into the workforce today have never really known a time without electronics," says Joe Maher, vice president business and product development, Hydro Electronic Devices (HED) Inc., Hartford, WI. "In the past, people were skeptical, and that evolved into acceptance. Now customers expect to have it, and engineers expect to design it into a machine system."

Today, the demand for electronic controls in all areas of the machine — not just hydraulics — has a pull-through effect on sales. Getting the word out no longer involves the "missionary selling of electronics," says Maher. "It is a fun time to be in electronics, I can tell you that."

Technology has improved. "I often compare the evolution that we are going through in our market with what happened in the automotive industry more than 20 years ago," says Maher. "Back then, when you bought a car, you wanted to avoid one with a lot of electronics because you didn't understand or trust them. Today, in most cases, you wouldn't want one without the luxury, safety, and economy features that can only be achieved physically or economically with electronics."

It is the system, not just the electronic components themselves, that has improved. "There is certainly more trust than in the past," says Terry Hershberger, applications engineering manager, Bosch Rexroth Mobile Hydraulics, Wooster, OH. "In addition, the proven reliability of the electronics that are on machines today, and the ability to troubleshoot with the available tools, have bolstered the confidence factor.

"Another major development that has increased confidence is that wiring harnesses are understood to be an important component in the design of the machine. In many cases it was not the electronics failing, but the wire harness. That is an important point in any discussion on trust of the system."