"It’s interesting that they chose capacitive [sensing] back there," said Randy Frank, author of Understanding Smart Sensors and chairman of one of the Sensors in Design tracks at this month's Design West conference. "In the past, vehicles have used infrared or sonic backup sensors to detect if they're getting too close to an obstacle."
Frank surmised that Ford chose capacitive technology because it offered the most logical way to distinguish between the various kinds of objects that could end up behind a car. "For a proximity sensor, it's going to be tougher to filter the cat or the basketball out of the algorithms."
Such a use may be a sign that capacitive sensors are beginning to creep into the vehicle. In-vehicle touch screens already employ the technology, and other areas of the car could follow suit. Audi and Volkswagen offer hands-free liftgate technology similar to Ford's, and we've reported before on Cadillac's plan to employ a capacitive center stack touch screen in its XTS and ATS luxury sedans.
Ford's use of capacitive technology is really just the tip of the automotive sensor iceberg. Today's vehicles are increasingly employing sensors of all kinds to let the control systems know what's going on around them. Resistive pressure sensors have found a home in intake manifolds and air conditioning. Optical sensors are playing a role in forward- and backward-looking systems. MEMS gyroscopes aid in stability control. Encoders monitor wheel speed, and resolvers are increasingly being used for motor positioning in electric cars. And with the advent of new touch screens and hands-free liftgates such as Ford's, capacitive technology is now making its entry into the vehicle.
"This just shows that automakers will explore any viable technology to achieve the results they're looking for," Frank said. "Capacitive just happened to make the most sense for this application."
DESIGN West Conference Information:
DESIGN West comprises seven summits. The conference takes place March 26-29 at the McEnery Convention Center in San Jose, Calif.
I know DesignNews continues to cover automobile data networks, but it is innovations like this liftgate sensor that makes them all the more imperative. As automotive engineers continue to instrument each sub-system on the platform, a common, multiplexed information network will be imperative as we continue. Yards of low-gauge automotive signal and power wire will only serve to increase cost and complexity. Can an on-board, distributed fiber-optic network be far behind?
Yes, this is a very clever idea. It will be interesting to see if it is useful enough to get picked up by the industry at large. Not sure this rises to the level of intermittent windshield wipers, but who knows?
Ever been stopped just as you were going to load your car? A neighbor calls your name, and you turn to see why, or your spouse calls from the front door to add to your shopping list? I can see this door giving you a whack from accidental detection, the "intent" described in the article.
Still, I like the idea very much; the cost added to the power package will be my deciding factor.
Mr. Weaver's comment about an onboard network is bang-on as well, though I don't think it will go to fiber optic. Bussed sensors (Devicenet or the like) already exist; getting them down in cost should work for mass auto production.
Oh, it's a plus, I agree. I rented a car last month, and enjoyed a keyless fob for the first time. Push-start, unlock doors as you grab the handle, just because the fob was in my pocket. It was quite an enjoyable experience.
I agree about not paying extra for it. Yet there have been countless times I've stood in front of a car's trunk with my arms full of grocery bags or luggage. Heck, I was cheap-thrilled when I had a car that had a button in the glove compartment that opened the trunk. My next car didn't have that feature and I actually missed it.
I have to admit, I'm a bit of a Luddite when it comes to extra features, so I probably wouldn't be willing to pay for this. The problem is, all features come in groups -- some optional, some standard -- and buyers often end up paying for them whether they know it or not.
I agree, Chuck. I don't pay extra for anything. Yet I've ended up with some nice features either because I bought a used car that happened to have features or the car that was on the lot (that I didn't have to wait for) happened to have features. Some of those features, though, have been fine -- like the glove compartment button that opens the trunk.
Rob, I never thought I would need automatic doorlocks on my cars, but now I'm hooked. It's a lot easier than turning around and locking every door in the car. It's easy to get used to some of these little luxuries.
The other "luxury" I've learned to like is the remote key fob. I wouldn't place it in the same category as automatic door locks, but I've learned to like the idea of hearing the beep when I remotely lock the door. I'm one of those people who can never remember if I've locked the door. By pressing on the key fob and hearing the beep, I know it's locked.
If you want the feature, why not put a kick plate on the back of the bumper or a switch next to the tow hitch? In both cases there is no need to verifying intent because you must be intentional to press the switch.
I personally think that we have way too many sensors and gadgets in cars. Lets keep it simple! The more complicated we make them, the more expensive cars become, the more likely they are to fail, and the more expensive they are to fix when they do fail.
I must say I like your "keep it simple" philosophy, VadimR, but we're going to lose that battle. Every time I attend an auto show, there's a handful of new sensor-based systems that I'd never seen before.
This is a great use of sensing techology to make something hands free and more user friendly. I would like to know how long it is necessary to keep your foot under the bumper to have the tailgate completely rise. Hopefully, you would be able to trigger the movement then be able to back up to stay out of the way of the lifting hatch.
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