Author Archive

Mirror-less Vehicles

The National Highway Traffic Safety Administration (NHTSA) is investigating the pros and cons of replacing conventional rear- and side-view mirrors with camera monitoring systems on passenger vehicles. NHTSA asked for experts, opinions, and research on the implications of making this change to passenger vehicles. On the one side, automotive designers and engineers say that getting rid of exterior mirrors would improve not only the aesthetics of automobiles but reduce their aerodynamic resistance as well.  Scott Miller, Director of Global CO2 Strategy, Energy, Mass and Aerodynamics for General Motors, says that exterior mirrors create aerodynamic drag while the vehicle is moving and removing them could produce a 1.5 to 2 miles per gallon gain. This is because according to Miller, 1 mpg in fuel efficiency is gained per 12-count reduction in drag and he expects a 20-count drag reduction per vehicle from the removal of two exterior mirrors. Further, a book published by SAE International notes that exterior side-view mirrors constitute anywhere from 2-7% of a vehicle’s total drag.

Two supporters of this initiative – the Alliance of Automobile Manufacturers (AAM) and Tesla – asked NHTSA to permit the installment and use of camera monitoring systems in vehicles instead of traditional mirrors. The foundational premises behind this petition are improved fuel efficiency and side vision; however, NHTSA did not grant them permission. NHTSA withheld approval in part due to a test it ran on a prototype camera monitoring system. While they found that the system proved “generally usable,” the test highlighted certain problem areas, including distorted images and problems in the rain. In other words, the test brought to light certain safety risks that could result from the implementation of cameras instead of mirrors. Therefore, before giving approval for camera monitoring systems on passenger vehicles, NHTSA seeks to further investigate the results of making such a change.

Taken from: www.sae.org

Simplifying the Driverless Truck

Engineers and innovators continue the push towards implementation of driverless vehicles into various sectors of the market. Launching driverless vehicles means, in part, overcoming the obstacles that hinder progress, such as driving in crowded, urban areas or bad weather. One of the sectors hoping to overcome such obstacles quickly is the trucking sector. Developers in this area seek to simplify the role and usage of driverless trucks to avoid as many unforeseen problems as possible while simultaneously implementing the technology into the market more quickly.

For example, TuSimple – a company that develops automated trucking systems –  may first deploy driverless trucks that stay on open roads and highways and avoid crowded cities since driving in crowded areas involves different and more complex technology. Another example is deploying driverless trucks solely in good weather for the same reason: navigating harsh weather requires different and more complex technology. By skimming down the functions and responsibilities of driverless trucks, TuSimple can get them on the road sooner.

Another way to introduce driverless trucks to the market sooner is by using a strategy known as “autonomous convoying.” This is where an actual driver operates one truck while a driverless truck follows. The logic behind this approach is that the driverless truck – while depending on its automated systems – can follow the experienced driver ahead, thereby reducing potential problems and issues for the driverless truck. For example, a human driver can read the construction signs ahead of time and know to slow down in advance. The benefits work the other way around as well: when the driver needs to sleep, he or she can have the driverless truck takeover while they sleep without having to pull over and stop.

The bottom line: driverless truck developers hope to see the technology implemented into the trucking sector sooner rather than later. Simplifying the functions and roles of driverless trucks can help overcome obstacles and jump-start implementation.

Taken from: www.sae.org

New Powertrain Technology Aims to Improve Engine Efficiency

Engineers and innovators continue to seek out new ways to improve engine efficiency, performance, and to reduce the amount of fuel consumed while driving. Changes to traditional systems in the internal combustion engine have already taken place and continue to advance the cause towards greater efficiency, but now engineers are looking to make changes to other parts of vehicles as well.

One area is the transmission. For example, the Detroit Integrated Powertrain Transmission has various sensors and controllers installed that improve engine performance by having the transmission communicate with the engine. The designers and engineers behind the technology believe these changes to the vehicle’s powertrain can help its engine produce power more efficiently. A variety of different functions exist, including one called eCoast which can sense what sort of terrain the vehicle is traveling on and then change engine rpm based on that data. When more power is needed, the engine rpms go back up to produce that power. Another function known as Skip Shift changes how the vehicle shifts through its gears while accelerating. Brian Daniels, manager of Detroit Powertrain and Components, explains that instead of a vehicle starting in first gear, then climbing from first gear to second, then from second to third, etc., Skip Shift technology can determine which gear the vehicle has the ability to start in. Daniels asserts that this technology can reduce the time and power needed to get up to speed which can ultimately save fuel.

Another change to traditional vehicle design is in the axles; specifically in their ratio design. Engineers and designers are looking to improve axle ratios in the hopes of improving fuel economy and efficiency. They assert that faster axle ratios enable vehicle engines to down-speed.  This means that the vehicle can maintain highway speeds at lower engine rpms and therefore consume less fuel without sacrificing functionality.

Taken from: https://www.sae.org/