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At CES Asia 2015 in Shanghai, Audi is showcasing a piloted driving technology study version of its new R8 e-tron battery-electric sports car, introduced earlier this year at the Geneva show. (Earlier post.) Audi is also featuring a piloted driving version of its A7 Sportback. (Earlier post.)
The R8 e-tron—340 kW (456 hp) of power, acceleration from 0 to 100 km/h (62.1 mph) in 3.9 seconds, and a driving range of 450 km (280 miles)—is based on the multi-material Space Frame of the second-generation production R8. The piloted driving technology study integrates a range of future technologies for lightweight design, high-performance drive systems and functions for piloted driving.
Piloted driving in China: the Audi strategy. Audi so far has focused its developments in piloted driving on the US and Europe. Chinese road traffic poses its own special challenges for automated driving functions, the company said. This is attributable in part to differences in driving behavior, but it is also due to the structure of the road network, in which urban freeways and regular streets are laid out directly above one another over long distances.
To offer driver assistance systems that are appealing to Chinese drivers as well, Audi launched a project at its R&D Center in Beijing in cooperation with Tongji University in Shanghai. The researchers developed solutions for specific local driving situations in China. The project is part of a strategy for solving specific local challenges and testing them in local road traffic. Audi has been successfully pursuing this strategy in the US for many years. The brand’s appearance at CES Asia represents the initial results of the company’s collaboration in China.
R8 e-tron piloted driving. The R8 e-tron rear car body module is made of carbon fiber reinforced polymer (CFRP) integrating the luggage compartment, which extends the frame structure. The walls of the luggage compartment shell are corrugated, so that they can absorb extreme amounts of energy with little material weight in case of a rear-end collision.
Due to specific modifications made to the outer shell and wheels, the Audi R8 e-tron piloted driving attains a low Cd value of 0.28. Its front end and sideblades feature e-tron specific lighting solutions.
The T-shaped 92 kWh battery pack (up from 49 kWh in the first generation) is structurally integrated into the center tunnel and behind the occupant cell; its low center of gravity further boosts the already excellent driving dynamics of the R8 e-tron piloted driving. The high-voltage battery is based on a new lithium-ion technology that has, for the first time, been specifically designed for the drive system of an all-electric vehicle, Audi says.
Although the pack energy capacity has grown from 49 kWh to approximately 92 kWh, the vehicle packaging is the same, due to optimized space utilization and improved battery cell technology. Audi produces the high-voltage battery itself.
The R8 e-tron piloted driving achieves an electric range of 450 kilometers (279.6 mi) instead of a previous 215 kilometers (133.6 mi) due to an increase in its energy density from 84 Wh/kg to 154 Wh/kg and several other modifications. The high-performance sports car has the Combined Charging System (CCS) on board, which allows charging with direct and alternating current. With this system, the customer can charge the large battery in significantly less than two hours.
The two electric motors each output 170 kW of power and 460 N·m (339.3 lb-ft) of torque to the rear axle. The R8 e-tron’s electronically-governed top speed is 210 km/h (130.5 mph) or 250 km/h (155.3 mph), depending on the car’s tires. Intelligent energy management and an electromechanical brake system enable high energy recuperation rates. Targeted torque vectoring—needs-based distribution of power transmission between the rear wheels—ensures maximum stability and dynamism.
The R8 e-tron piloted driving technical study is equipped with all of the functions of piloted driving. Data is acquired from the interplay of an array of sensors: a new type of laser scanner, several video cameras, ultrasonic sensors and radar sensors at the front and rear. Based on signals from these sources, the central driver assistance control unit (zFAS) (earlier post) computes a comprehensive picture of the vehicle’s environment.
Audi can build the R8 e-tron in handcrafted quality to meet special customer requests. The company uses its high-performance electric sports car primarily as a high-tech mobile laboratory.
Piloted driving Audi A7 Sportback. Journalists at CES Asia can ride along in the piloted driving Audi A7 Sportback prototype over an approximately 15 km (9.3 mi) route through Shanghai that starts and ends near the trade fair site.
The test vehicle utilizes various production and near-production sensors. The long-range radar sensors of the adaptive cruise control (ACC) system monitor the zones in front of the car. A near-production laser scanner is mounted in the Singleframe grille. The sensors provide redundant information on stationary and moving objects they detect during the piloted drive. A high-resolution video camera by partner Mobileye, a prototype for a future generation of such devices, offers a wide-angle view in front of the car.
The function for piloted driving in traffic jams, which Audi is currently developing, is based on radar-supported adaptive cruise control (ACC) including traffic jam assist that will launch on the market in the new Q7. The system offers relief to drivers in dense highway traffic by handling steering tasks between 0 and 60 km/h (37.3 mph), and it accelerates and brakes autonomously. When the traffic jam pilot reaches its specified limits, such as when the traffic jam resolves itself, or the end of a divided highway is reached, the system prompts the driver to take control of the vehicle again. If the driver does not do this, the system safely brings the car to a stop.
In the future system for piloted driving, the radar sensors will remain an important component of the sensor array. They will acquire information from the zone in front of the car as they do today. A video camera with a wide angle lens detects the lane markings as well as pedestrians and objects, such as other vehicles and guard rails. Up to twelve ultrasonic sensors are used to monitor the immediate space around the car.
A new member of the sensor array is the laser scanner – it delivers highly precise data on objects at a distance of up to 80 meters (262.5 ft). Its laser diode emits nearly 100,000 infrared light pulses per second that are invisible to the human eye.
The control unit computes a surroundings profile from the light reflections. The laser scanner covers a range of 145 degrees on four vertical levels. Because of its wide aperture angle, it can detect vehicles that are merging in front of the car very early on. It also operates in the dark without any limitations. It can detect any objects – including those that exhibit a uniform pattern, such as fences, or objects that do not have any visible texture such as white walls.
Piloted driving related to parking. Piloted parking from Audi will let drivers exit the vehicle and conveniently control the car remotely with the remote key fob or a smartphone. To acquire information about the environment, the system utilizes twelve ultrasonic sensors, four top view cameras and a laser scanner. This produces redundant verification of the parking process.
The parking pilot offers the piloted parking function to the driver when the environmental sensors detect a suitable parking space or a garage. When drivers get out of the car, they only need to press the relevant button on their key fob or smartphone to initiate the process. Drivers are still responsible for the entire parking process until the car is stopped. The system requires that the vehicle key be located in the immediate vicinity of the car, so that the driver can evaluate the situation at all times.
If the on-board sensors detect obstacles in the driving corridor during piloted parking, the parking process is stopped immediately. Central locking is in the locked state throughout the piloted parking process. When the parking position is reached, the engine is shut off, and the car is secured against rolling. The driver gets a confirmation message. Retrieving the car from the garage or parking space is just as easy.
In 2013, Audi demonstrated piloted parking in its full functionality for the first time. The car was parked at the entrance of a parking structure, and the parking process was activated by smartphone. The driver could later use an app to retrieve the vehicle or schedule a specific time for the vehicle to be available at the exit.
At CES Asia, which opened today in Shanghai, Cadillac and GM’s Shanghai OnStar joint venture are showing China’s first automotive 4G LTE telematics service along with the CarLife app; the My Cadillac app; and an Apple Watch app.
Later this year, Cadillac will become the initial vehicle brand in China to offer 4G LTE telematics service. Shanghai OnStar’s partnership with China Mobile, the world’s largest wireless telecom carrier, will support a fast, stable, reliable, safe and convenient telematics network.
Cadillac is also taking advantage of CES Asia to introduce the CarLife app, which will begin appearing in Cadillac models in China in 2015. The technology projects vehicle service information from a user’s smartphone onto the vehicle’s touch screen. It supports various mobile device operating systems, including Android and iOS.
In addition, CES Asia visitors can experience the MyCadillac app for smartphones and an Apple Watch equipped with the OnStar app. The technology allows users to lock and unlock vehicle doors, remotely start their engine, flash their headlights and sound their horn, locate parking spots and access real-time information about vehicle systems.
A team from Germany reports that a 40 wt% Pt3Cr/C alloy fuel cell catalyst shows enhanced activity under both half-cell and full-cell conditions as well as excellent corrosion stability compared to those of the 40 wt% Pt/C benchmark catalyst.
As presented at the Meeting of the Electrochemical Society earlier this month, in half-cell experiments at 2 mA cm−², the Pt3Cr/C catalyst exhibited 10 mV less over-potential and two-fold higher specific and mass activity for the ORR (oxygen reduction reaction) than Pt/C. The average particle size grew from 4.5 nm up to “only” 6–8 nm after 7000 degradation cycles. By comparison, the average particle size of Pt/C increased from 4.5 up to 10–30 nm.
After 1,000 degradation cycles in a full cell, a MEA (membrane electrode assembly) with a Pt3Cr/C cathode exhibited an excellent maximum power density retention of about 94% compared to only 59% for the MEA with the commercial catalyst. The paper is also published, open-access, in the Journal of the Electrochemical Society
Search for highly active and corrosion-resistant low-cost catalyst represents a huge challenge for fuel cell development and large-scale commercialization. Platinum is still considered as the state-of-art for cathode catalyst material in polymer electrolyte membrane fuel cells (PEMFC). However, it exhibits a slow kinetics for oxygen reduction reaction (ORR) that is mostly due to the strong bonding energy of the oxygen molecules (494 kJ mol−1) on Pt sites as well as the presence of adsorbents. The poor long-term stability of the Pt nanoparticles, Pt scarcity and the exorbitant price of raw material (1500$/oz) are also crucial issues as well. For these reasons, reduction of Pt loading by alloying Pt with a less expensive and abundantly available transition element appears to be an attractive approach whereas corrosion of non-precious metal is still a controversial concern that is also generally depending on synthesis route, degree of alloying, particle size and morphology, temperature treatment, and finally on interaction/confinement with/within the support.
… One of the most impressive screenings was conducted by He et al. who deposited a thin film of binary Pt catalyst with different composition by multisource physical vapor deposition (M-PVD) of metallic targets on substrate arrays. Among the 15 tested Pt alloys, PtNi showed a 35 times higher mass activity than that of pure Pt followed by PtFe (30 times), PtCu (20 times) and PtCo (13 times). Surprisingly, the Pt3Cr system exhibited a modest twofold higher activity than that of Pt, but excellent corrosion stability compared to that of the more active alloy catalysts.
… Although Pt3Cr alloy was often qualified as a both active and chemically stable catalyst for ORR, we found astonishingly no scientific contribution focusing on its performance behavior in H2-PEM and only a few ones related to alcohol fuel cells. This work aims at the development of a 40 wt% Pt3Cr/C catalyst for H2-PEM cathode.—Sakthivel et al.
M. Sakthivel, I. Radev, V. Peinecke and J.-F. Drillet (2015) “Highly Active and Stable Pt3Cr/C Alloy Catalyst in H2-PEMFC” J. Electrochem. Soc. volume 162, issue 8, F901-F906 doi: 10.1149/2.0761508jes