We keep hearing pundits talk about all the processors in today’s cars (“at least 100” is the number very commonly cited), and it’s true. But the complementary reality is that vehicles are now sensor-laden platforms on wheels. Under the broad heading of ADAS – advanced driver-assistance systems – there are mandatory safety subsystems such as those for anti-rollover, back-up camera, and tire pressure; non-mandated functions such as adaptive cruise control, lane-departure warning, and drowsy-driver detection; and general driver information and entertainment features such as GPS…well, you can make your own list. Of course, there are also those essential functions needed to just start and keep the car running, generally hidden away in the power train and elsewhere.
Many of these sensors are “outward facing” in that they transmit some sort of signal from the vehicle and look at the response; others are passive sensors. The push for the autonomous (both partially or fully) vehicle is adding to the number and diversity of auto sensor input/output, Figure 1 .
This broad overview shows some of the external-facing sensors and systems in present and upcoming cars; the dozens of internal-only sensors are not shown. (Image source: Laser Focus World)
We can debate the virtue of having so many of these sensors and their associated analog support components in the car, and there are valid arguments on all sides. Some things are for sure: all those sensors cutting across RF, optical, and thermal domains mean good times for vendors and analog-focused designers.
So far, so good. But there’s a “no good deed goes unpunished” aspect to all this, with immediate, mid-term, and long-term consequences.
First, the price of new cars has increased steadily, partially but not entirely due to all these electronic and electromechanical systems mandated or otherwise, Figure 2 .
The price of new cars has been rising faster than inflation and electronics in general; much of it is due to added features and functions, some discretionary and some mandated. (Image source: Statistica)
As a follow-on consequence, the price of used vehicles has also risen. Of course, there’s some counter-argument that cars are more reliable and so less expensive in the long run, but for the buyer, that may not offer solace. Further, the next factor may negate the longevity argument.
Second, repair costs have also increased sharply; one report claims a 23% increase in collision-repair costs between car generations, see here. (Other studies which look at these repairs from different perspectives have roughly similar numbers). Now, even a basic “fender bender” means more than replacing metal or a few lamps. Instead, there’s likely an expensive electronic module that needs to be replaced a well. After all, a complete GHz-band radar subsystem costs several hundred dollars, for sure. That parts cost is not the end of the story, either, as many of these replacement units need to be tuned and trimmed to the specific vehicle after replacement, just as new tires need to be balanced and front ends aligned. So, there are higher parts and labor costs here as well.
Third, there’s the issue of obtaining replacement assemblies after 8, 10, 12 and more years. Auto manufacturers insist that their suppliers commit to long-term support, but reality is that “stuff happens” and replacements for a 10-year old car may be hard to find, costly, and may not be in the best shape, even if they have sat on a shelf untouched for years. The average car lifetime has lengthened from about 10 years in 2004 to 11.4 years in 2014 (see the U.S. Department of Transportation detailed statistics here); of course, many are older than average. Analysts cite two reasons for the increase: yes, cars are more reliable, and they are costlier. But accident-driven repairs are not a direct function of the car’s age or reliability, as newer cars have their share of accidents, too.
So what’s this all mean? In short, I have no idea. As Yogi Berra reportedly said, “predictions are very hard to make, especially about the future.” I do know that the trends are difficult to see early on, while extrapolating from a few early years of data is very risky for two reasons. First, there’s only a small baseline value and errors there can lead to missing the target by a wide margin; second, easy-to-make statements such as “at this rate, XYZ will happen” are foolish because reality is not linear, there are inflection points, saturation levels, and more (after all, extrapolating the state of liquid water versus temperature does not tell you at all what happens below 0o C or above +100o C).
Many years ago, Saab advertised that their cars were as sophisticated as the fighter jet aircraft they also made (yes, Saab made both; the fighter business has since merged with a larger aerospace company). One commentator noted that average car owners really don’t want a car that’s as advanced and complex as an airplane, which needs hours of maintenance for every hour of use and large ground support crew. Perhaps we are going along that path anyway, and that ad was prescient but in an unintended way!
Check back in a few years; it will be interesting to see what happens, and to what extent. Engineers usually like to “keep it simple” for many well-known reasons, but this trend is going the other way by a large factor. In the interim, it’s a great topic to talk about since everyone can make a valid, rational case for their view. One thing is for sure, though: vendors of sensors and sensor I/O, along with the engineers who design them into vehicles will be very busy.