It’s a tough job sorting through the widgets, gizmos, and candy dishes filled with Halloween leftovers to find evidence of technological solutions to problems we might not have even conceived of as yet, but each year we invest the shoe leather and alimentary distress to bring you news of scientific and manufacturing advances that promise to brighten our collective automobility future. Please enjoy highlights of the 2017 Society of Automotive Engineers World Congress, more hiply referred to now as WCX17.
After eight years of R & D and considerable testing with a Big Three OE, Minnesota-based Hansen Engine Technologies introduced its variable-displacement supercharger at SAE. The idea is pretty simple: Never tax the crankshaft with creating air pressure the engine can’t use. The unit employs a Lysholm type positive displacement twin-screw supercharger, but there’s a sliding window in one side of the housing. When that window is open, no pressure is generated, so there’s just a bit of frictional load on the crankshaft. The system is set up to use a typical throttle to control airflow into the engine. It gets to wide-open when the accelerator’s about a third of the way down. The additional airflow required for the next third of the pedal travel gets met by compressing the intake air, gradually closing the window in the blower housing. (Compression only happens in that portion of the housing that is closed.) Pressing the accelerator farther will trigger a downshift and higher-rpm engine speeds that would result in a typical turbo or blower opening its wastegate, but here the window just starts opening back up. The result is turbo efficiency with the superior full-range engine responsiveness of a supercharger. If further testing bears out initial results from converted turbo engines, this concept could become a real disruptor in the booming downsized pressurized engine market.
Technically this engine, the brainchild of Waukesha, Wisconsin-based Monolith Engines, was not present at SAE, but its engine block was. Interesting in its own right, it was cast using Tooling & Equipment International’s 3-D-printed sand-casting molds. Inside this small casting is a single long cylinder. Two opposed pistons run in this cylinder, but the kicker is that they are each double-sided, so there’s a combustion chamber between the pistons and two more on the outer ends of the long cylinder. A pair of crankshafts flank the cylinder, connecting to the center of each double-piston. This symmetrical power takeoff ensures the pistons stay centered in the cylinder to minimize friction. The engine is fuel injected, and breathing is via ports, not valves. No oil is mixed with the intake air. The two-stroke concept comes by its “One-Cycle” nomenclature by virtue of the fact that the pistons are always being directly driven in each direction, never being towed or pushed by another piston’s work cycle. The 1.2-liter engine measures just 24-by-12-by-5 inches and is expected to weigh just over 80 pounds while producing 200 hp. It is envisioned as a stationary power generator or range-extender for hybrid electric vehicles.
German Tier 1 supplier Rausch & Pausch GmbH (Rapa for short) has been making Active Body Control hardware for Mercedes-Benz and similar products for others, but a Mercedes SUV coming to market this summer (GLS-Class in all likelihood) will be the first to use a new active hydraulic shock absorber product that achieves similar aims. Instead of relying on centrally pumped and distributed hydraulic oil or air as previous ABC designs have done, each corner will get its own fast-acting, 48-volt, electric-powered hydraulic pump. These pumps are capable of switching directions five times per second (5 Hz)—quicker than the typical frequency of car body motions, which is generally 2–3 Hz. The shock absorber internals are fairly typical, but the flow of oil can obviously be driven so as to place a wheel down into a pothole sensed by forward-looking cameras then pull it back up out of that hole. Or, when driven passively, the gear-set oil pump can actually recuperate electrical energy from the suspension. As with other ABC systems, this one should greatly reduce or eliminate the need for anti-roll bars. Total system cost is expected to pencil out as neutral relative to previous ABC setups after production volumes ramp up.
Big car companies have whole departments dedicated to buying competitor vehicles, tearing them down, and analyzing what makes them tick and how much they cost to build. When they’re done, the vehicle is scrapped. Caresoft Global Inc., of Burr Ridge, Illinois, has a new, “minimally invasive” means of reverse-engineering competitive vehicles with the help of a giant 9 megavolt X-ray machine and a whole bunch of software to interpret the results. For scale, roughly 100 kilovolts is typically the power employed in medical CT scanners used to diagnose human ailments. Hence this machine lives in a big lead-lined concrete bunker. After three weeks of scanning a Tesla Model X P90D, the company had enough data to provide a geometric model of most of the constituent parts of the car (in any of several neutral file formats such as IGES and STEP, or Arcadia for the wiring). Some particularly close-tolerance parts must be disassembled and rescanned to guarantee accuracy—but at the end of the process, a complete CAD model of the vehicle is produced. The machine senses part density and hence can distinguish ferrous materials from aluminum, plastic, etc., but it can’t determine alloys, so producing a computer model suitable for crash-test analysis still requires destructive analysis of many body components. But Caresoft knows of no other technology that can produce a complete model of the entire wiring harness without taking anything apart. That’s pretty cool. And if you’re wondering, that megavolt scanning doesn’t negatively affect the battery pack or any other subsystem, according to extensive post-scan testing by Caresoft. The company’s proprietary costCompare value engineering software can even produce a cost estimate. Next up for electro-dissection are the Chevy Bolt, Tesla Model 3, and Hyundai Ioniq. The cost of these initial scans is quite high but is expected to plunge quickly, and Caresoft hopes to soon be able to offer a more comprehensive competitive assessment package for less than the cost of an OE generating the info itself via traditional tear-down methods.
Turbocharger turbines can spin way over 100,000 rpm, but they all have a maximum safe speed. To keep turbos safe, large heavy-duty turbos usually include a speed sensor that looks for a flat spot ground into the turbine shaft to measure rpm, but there’s no room for such devices on most light-duty turbos. So they usually use math to infer the turbine speed given the boost pressure and air flow rates. Such calculations must include a safety factor to ensure the turbo doesn’t overspeed due to a misread of sensor data, and this safety factor can result in potential power being left on the table. The Swiss-based global speed-sensing experts at Jaquet are proposing moving the sensor to the cool side compressor housing and changing from variable reluctance to eddy-current sensing. This new type of sensor detects the tiny change in conductivity that occurs every time a compressor blade passes it. Advantages are that it works at very low speeds, where the shaft sensors only work at higher speeds. As OBD regulations tighten, manufacturers will need greater redundancy. This sensor helps provide that. It’s already in use in some high-end Bentley models, and it is expected to propagate through smaller, cheaper engines soon.
Last year we reported on the migration of Corning’s Gorilla Glass from smartphones to automotive greenhouses, and this year the team returned to SAE to show the product coming full circle: being used in interior displays. If you love the scratch- and impact-resistance of your phone’s touchscreen, you’ll appreciate the same characteristics on your car’s infotainment screens. Gorilla Glass can be coated, painted, and decorated as a flat sheet and then curved to suit the interior design. (It’s way easier to print on flat surfaces than on curved ones.) There are a few caveats: There are limits to how much curvature it can tolerate, said curvature must be purely cylindrical—no compound curves—and the glass must be mechanically retained in that shape. If it comes out of its frame, it’ll spring back to the flat shape it was born with.
Want to keep that Gorilla Glass display free of fingerprints? Well, the glass coating specialists at Massachusetts-based NBD Nano might have just the thing. The company specializes in coatings that attract or repel water, oil, etc. Unlike many fingerprint-reduction technologies that attempt to repel oil (oleophobic coatings), NBD’s approach with InvisiPrint is to attract and disperse the oil (oleophilic). We’re not getting into the nitty-gritty chemistry except to note that it’s a hybrid organic/inorganic compound. A significant part of NBD Nano’s secret sauce is a NanoGlue glass-grafting primer technology that makes its coatings last far longer than most. This primer involves molecules capable of establishing 64 to 200 cross-linking layers with the glass, whereas the molecules in most such primers can only manage a handful of such links. NBD Nano’s hydrophobic (water/dirt/bug-guts repellent) coatings are currently on test with numerous OEs for keeping camera and lidar lenses clear—an important prerequisite to autonomy.
Plenty of vehicles boast combustion front-wheel drive with an electric rear axle, but the e-AAM unit adds an interesting twist—to the outside wheel in a turn. Yes, there’s a torque-vectoring mode, but it works differently than most. The motor connects to the axle with a single-speed gear reduction of between 9:1 and 11:1, but there’s also a planetary gear set that enables three modes: neutral (to disconnect the electric motor at high speeds or when it’s not needed), open-differential mode, and torque-vectoring mode. In this mode, spinning the motor in one direction or the other biases torque to the outside wheel in right- or left-hand turns. Note that the e-AAM isn’t providing any propulsion per se during such a torque-vectoring application. AAM has another version in the works, which adds a second electric motor to permit simultaneous propulsion and torque vectoring. The system is not yet in production, but more than one OEM is working to bring the concept to production in one of its many size and torque capacities.
This concept axle comprehensively rearranges the gears and bearings in a typical rear-drive axle to achieve a 20 percent increase in torque density with a 30-percent reduction in mass. It’s also smaller and more modular because many components and half the housing can remain the same while the other half provides the option of open gearing, electric or mechanical locking, or even torque vectoring. Cake icing: The shims that are used in a traditional axle to ensure that the hypoid gears are installed precisely for optimum durability and NVH get ash-canned while noise drops by 5 dB. AAM is in talks with several OEs targeting production in or before 2021.
Controlled Power Technologies blazes a new trail by proposing use of a switched-reluctance motor in a mild hybrid application. Switched-reluctance motors are less power dense than other motor types, but they’re simpler and cheaper to make because they involve neither permanent magnets nor electric windings on the spinning rotor. Instead, the ferrous rotor nodes are accelerated in either direction by stator winding currents that must be rapidly switched. They’re commonly used in stepper motors, disc drives, etc. They can also be motored or generate electricity in either direction, which makes this particularly useful for applications where the motor is applied after the transmission or on the axle (P3 or P4 hybridization). Envisioned as a 48-volt device, two sizes are currently offered, good for 7 or 15 kW peak motoring power 10 or 20 kW peak generating power at 80 and 88 percent efficiency, respectively.
Modern car design is all about cool lighting, and cool lighting is all about not seeing hot spots: the source of the illumination. German chemical company Evonik’s Acrylite group showed off two products that aim to do that: EndLighten is designed to be lit by LEDs from the edge. When there’s no light, the plastic looks clear, but when edge-lit, particles in the acrylic sheet scatter light outward so the whole panel glows. Another product, Satinice, is designed to completely diffuse a light source so that there’s no trace of the source LED chips. This one’s 86 percent diffusion means that typical taillamp sources are not powerful enough for the light to reach regulation distances, requiring more powerful light sources or fitment to unregulated light sources. The final product on display was Resist AG 100, a tough, scratch- and impact-resistant acrylic product that is currently undergoing testing for approval in headlamp lenses. The material reportedly does not haze or turn yellow after prolonged exposure to UV radiation like today’s polycarbonate lenses do. It’s currently in use in some ATV models.
Sometimes it’s the tiniest things that make a difference. California-based pressure-sensing experts at Trensor are proposing to integrate an air-conditioning pressure sensor into the access cap used to replace the receiver-drier unit. Doing so eliminates three potential leak paths (an O-ring, a valve, and a brazing joint), saves 1.4 ounce of aluminum, and simplifies the assembly process—all of which adds up to a savings of $2.50 per car. The system is mocked up on a Chevy Cruze condenser, but no production plan has been announced yet.
See future-car tech highlights from previews SAE World Congresses here:
