Electronics functionality keys auto improvements

With the increasing electronics content in automobiles and other vehicles, many functions that were historically mechanical, such as steering, suspension, and braking, can be more precisely controlled and integrated together. The result: improved safety, handling, and comfort.

Design News: How do you see electronic systems improving auto chassis design?

Ziebart: Over the next decade, we see mechanical components offering little opportunity to have impact, except maybe in lighter materials such as aluminum, [on chassis design]. The main impact of electronics will come in two ways. Functions performed purely by mechanical means, such as damping and steering, will be equipped with electronics. More important will be the connecting of different systems to get new functionality. For example, on our 30-Meter Car, which stops within 30m from a speed of 100 km/hr (see DN 7/2/2001, p. 23), we controlled the damping from the brake controller [based on] brake force applied. Or, in the future, you could connect the brakes with the steering and have both systems "talk" to each other when braking in turns.

Q: What will be the impact of such electronic integration on safety systems?

A: Electronics will merge chassis control systems for active safety with passive-safety systems. For instance, the airbag controller can be combined with [sensor] inputs for new functions, such as activating passive safety features (i.e. tightening seatbelt retainers) when chassis control electronics detect an "out of control" condition [before any impact].

Q: What other integrated functions do you see electronics making possible?

A: We could look at stability control linked to steering or perform automatic control of oversteer. One controller in a car could be used for controlling not only brakes, but also steering. This could counter side-wind effects automatically without any driver input.

We are active in steer-by-wire, but far away from that now. While we don't manufacture steering, we can bring in all electronic components a steering manufacturer needs to offer control. We see the impact in the steering industry in the next few years.

Q: What have been some other recent improvements in electronic systems?

A: With the 30-Meter Car we learned how to design a car for improved braking without compromise in other areas. In electronic braking systems in production, we've already implemented new algorithms as part of our continuous improvement program. Cars today, compared to five years ago, have 8 to 10% less braking distance chiefly due to algorithm improvements for wheel-speed control. We are discussing with automakers the introduction of pressure control in ABS units to control longitudinal braking force. We see an additional 5% improvement in braking distances because of this in about two to three years' time.

Q: What do you see as the impact of prospective 42V automotive electrical systems?

A: For electronic braking and stability there is little impact other than systems getting lighter. The main impact will be in areas where currently it is too "heavy" to bring in electronic control and in subcompact size cars-anywhere higher power can be used but where it is now too heavy or uneconomical to implement. Electronics has performance advantages and cost savings, and 42V will bring up the "border" where electric motors, for example, become useful in [applications for] more than one or two classes in a manufacturer's model range.