From occupancy sensing systems for airbag deployment to electronic engine control units and collision avoidance systems, electronics are controlling more and more functions in today's automobiles. But is such a trend all good for automobile designers and owners? Edward Hart, president of Wabash Magnetics' Automotive Products Group, a company specializing in state-of-the-art sensor technology, shares his insights.
Design News: Walk the SAE show or go shop for a car today and it's obvious that the automotive industry is in the middle of an electronics revolution today. What's your take on this ongoing trend?
Hart: I'm now old enough to say that when I was a young man, we used to talk about the future impact of electronics on automobiles. Well today, almost everything that we talked about--and more--has happened. Clearly, electronics have been a required addition to the latest generation of automobiles. The two biggest and most important areas have been in vehicle emissions and safety, where it would be impossible to meet today's standards without some type of electromechanical control.
Q: Some critics say that we've gone too far. They say all that the growing use of electronics has done is drive up the cost of cars and automated many features that car owners don't need and can't afford.
A: I would say that those critics make a fair point with regard to some of the convenience features that you find on cars today. But it's a different story when it comes to safety and fuel emissions. These systems are needed and, in general, designers have done a good job to eliminate excess cost. Most recently, the pressure to drive cost out of these systems is stronger than ever. One of the initiatives within the automotive industry right now is to try to standardize on more commodity class products, so that suppliers can buy them more broadly...and at lower cost.
Q: What challenges does the trend toward greater use of electronic and electromechanical systems pose for design engineers?
A: In general, the automakers have done a superb job in adapting to this technology. In fact, American companies led the way because of our mandated emission requirements. But I think what any engineer can relate to is the relative simplicity and reliability of a mechanical system. Let's take for example the steering system in a car. It's a straightforward mechanism--the steering wheel is firmly connected to the front wheels. But an all-electric system has some major advantages in fuel economy. So the sensible engineer is going to need to think through all of the implications and consider what kind of redundancies he or she is going to need to build into the system to ensure that it operates at the same level of reliability.
Typically, there is an evolution in technology. With brake-by-wire, for example, what we'll probably see initially is some sort of hybrid system. We'll go through a series of steps from an electronically assisted braking system to one eventually where the pedal is truly disconnected from the brakes.
Q: Is there a reliability concern with electronic systems?
A: If there is, I think that it's mostly emotional today. I make the comparison that in dealing with home systems, Underwriters Lab wants to see an electrical switch in a circuit, so that when it's open, it's truly open. As we sometimes joke, a semiconductor switch is another way of saying it sort of conducts. Either way, you still don't want to stick your finger in a light socket! Seriously, I think the reliability of today's cars, with their highly complex electronics, speaks for itself. Our cars are fantastically good today.
Q: What does today's design engineer need to know in order to stay on top of all of the changes in technology?
A: Every design engineer today needs to be conversant in the broadest possible range of technologies.
Q: What new innovations can we expect to see coming down the pipeline in automotive electronics?
A: One of the most exciting technologies that we see on the horizon is in the whole area of semiconductor-based positioning devices. While the promise of these non-contacting devices has been well-recognized for sometime, I think the cost and reliability of them has now improved to the point that we will soon begin to see some practical applications.