It’s been nearly a quarter century since I first rode in a car with my feet off the pedals and my hands in my lap, watching it negotiate turns while remaining centered in its lane and maintaining a safe following distance from a car in front. It even managed the auto stop-and-go trick.
The test car was a Nissan Cima/Cedric/Gloria sedan, and it was chauffeuring me around a proving ground in Japan. Back then the prospect of semi-autonomy was new and exciting. These days I feel like I’ve seen and heard everything there is to know about the various stages of autonomous transport. But recent supplier tech-day events introduced tangential aspects of the topic that awakened my long-dormant interest enough to warrant sharing them here.
Comfort Maneuvering. ZF has built a “Vision Zero” electric concept car equipped with its electrified mSTARS modular semi-trailing-arm rear suspension, which can steer the rear wheels by up to 8 degrees. You know how some surround-sound stereos can optimize the listening experience for the driver, the front seats, or all passengers? Well, this concept can optimize for motion comfort the same way. A slider reprograms the amount of front and rear steering that occurs for any given maneuver, effectively repositioning the pivot point around which the car rotates fore and aft. I was riding in back, and when that point aligned with my body, the turns felt much more serene.
The Vision Zero concept also gave me my first taste of a zero-yaw lane-change maneuver. This is where the front and rear axles steer in perfect unison while passing. This maneuver would feel weird if you were turning the steering wheel, but a carload of heads staring at phones might not notice the maneuver at all. As full autonomy gets more riders staring at devices instead of out the windows, motion sickness will be a problem and fixes like these will be invaluable.
Bag in Roof. Although autonomy promises to drastically reduce the global accident rate, during the transition period when human and robot drivers share the roads, we’re still going to need crumple zones and airbags. But steering wheels that disappear into the dash make lousy airbag mounts, and airbags that blast directly at us risk smashing our glass-screen devices into our faces. ZF’s solution: Deploy airbags from the ceiling so they knock devices into our laps while cushioning us. One such airbag is already in use in the front passenger seat of Citroen’s quirky C4 Cactus.
ContiAdapt wheel/tire. Autonomobiles perceive their environment more thoroughly than humans can, and Continental’s ContiAdapt tire/wheel concept allows vehicles to use this added info to program their own footwear.
By varying both wheel width and tire pressure on the fly, this concept tailors the contact patch size and shape to suit conditions in real time. High pressure and moderate wheel width creates a longitudinally short, broad patch for low rolling resistance. A narrow width and high pressure makes for a longer, narrower patch that reduces the likelihood of hydroplaning in the rain. A wider rim and lower pressure help maximize comfort or—with pressures as low as 14 psi—boost traction when launching in deep snow and improve grip on ice. (Exactly how the “hub-mounted compressor” works and how the rim varies its width without compromising the seal has yet to be explained.)