Audi introducing electric 1+1 urban concept at Frankfurt with support for wireless charging; more detail on electric A2 concept
|Audi urban concept with support for wireless charging. Click to enlarge.|
Audi is introducing a 1+1 urban concept technology study for urban and metropolitan areas. The electric-powered show car has four wheels, combines elements of a racecar, a roadster, a fun car and a city car, and weighs just 480 kilograms (1,058.22 lb). The cabin of the Audi urban concept offers slightly offset seating for two; the roof slides back for entry, and the canopy can remain open in good weather.
Audi says the technology study is targeted toward people who are interested in technology and are enthusiastic about new approaches to mobility, independent of their age and status. In particular, it addresses an urban public whose lifestyle both reflects the car’s modern concept and the driving pleasure associated with it and is a good fit for a possible innovative leasing system.
The outer skin of the show car is made of carbon fiber-reinforced polymer (CFRP); the occupant cell is a mix of CFRP monocoque and an aluminum structure. This ultra-lightweight construction is the foundation for the technology study’s low curb weight of 480 kg.
Wishbones made from a combination of aluminum and CFRP locate the free-standing, 21-inch wheels.
Manufactured using cladding technology, the 21-inch wheels are very light and feature a variant of the blade design from the Audi e-tron models. The tire sizes are as unusual as the car as a whole – 125/60 up front and 145/50 in the rear.
The Audi urban concept uses pushrod technology borrowed from motorsports. As in a racecar, the struts mounted in the interior of the monocoque are nearly horizontal. Four disc brakes provide the stopping power. The turning circle measures less than nine meters (29.53 ft)—ideal for a city car. Thanks to the vehicle’s low weight, the rack-and-pinion steering does not require any power assistance. Crumple zones in the front and rear plus two airbags provide for a high degree of passive safety. An innovative assistance system helps the driver to avoid collisions with pedestrians.
The battery is mounted transversely behind the seats. The lithium-ion battery, which weighs around 90 kilograms (198.42 lb), stores 7.1 kWh of usable energy. The study’s two electric motors together produce 15 kW (20 hp) of continuous power and 47 N·m (34.67 lb-ft) of torque. The motors are mounted between the rear wheels, which they drive via a single-speed transmission.
The Audi urban concept accelerates from 0 to 100 km/h (62.14 mph) in 16.9 seconds. It reaches 60 km/h (37 mph) in around six seconds. Top speed is governed at 100 km/h (62 mph). Range in the European driving cycle is 73 km (45 miles). The battery recharges completely in about 20 minutes with 400 volt three-phase current, and in approximately one hour with 230 volt household current.
Audi Wireless Charging. Audi Wireless Charging (AWC) refers to contactless induction charging. The infrastructure side, comprising a coil and an inverter (AC/AC converter), is placed on the normal parking spot of the Audi urban concept and connected to the power grid. The 3.6 kW primary coil set into the plate generates a high-frequency alternating field.
The charging process begins automatically when the urban concept drives onto the plate. The alternating magnetic field of the infrastructure side induces an alternating current across the air gap in the secondary coil, which is integrated into the vehicle. This current is rectified and fed into the vehicle’s electrical system, where it charges the battery or powers consumers such as the heater. The alternating field is only generated if the vehicle is standing over the plate and thus poses no danger to people or animals.
Charging stops automatically when the battery is fully charged. The driver can interrupt charging at any time. The efficiency of AWC is comparable to that of other charging technologies. It is not affected by rain, snow or ice. The new technology makes charging electric vehicles easy and extremely convenient. A later version of the technology will be able to be integrated into the transportation infrastructure as a retrofit for parking garages or residential streets, for example.
|The A2 concept. Click to enlarge.|
The lithium-ion battery mounted in the sandwich floor stores 31 kWh of energy, 24 kWh of which are usable. The electric motor is transversely mounted in the front of the vehicle. It delivers 85 kW (116 hp) of peak power (60 kW continuous) and 270 N·m (199 lb-ft) of torque (160 N·m (118 lb-ft continuous) to the front wheels via a single-speed transmission.
The Audi technology study has a range of 200 km (124 miles) in the European driving cycle. It takes roughly 1.5 hours to fully recharge the battery with 400 volt three-phase current and approximately four hours with 230 volt household current.
The show car weighs less than 1,150 kilograms (2,535 lbs). This is due primarily to its body, which features the most advanced state of Audi’s ultra-lightweight construction. The A2 concept marks the first time that the ASF has been combined with hybrid multi-material construction, in which very different materials are combined with one another. In this case, the superstructure is made largely of aluminum components and is complemented by add-on parts of carbon fiber-reinforced polymer (CFRP).
The Audi A2 concept accelerates from 0 to 100 km/h (62.14 mph) in 9.3 seconds; top speed is limited to 150 km/h (93 mph) in the interest of range. A McPherson strut front suspension and a torsion beam axle in the back provide for agile handling. The steering and brake systems are purely electric (steer-by-wire and brake-by-wire), requiring no mechanical or hydraulic connection to the steering wheel or the pedals, respectively.
The 18-inch wheels are fabricated using cladding technology. The alloy base wheel and the cladding are manufactured separately and bonded together, reducing the amount of material used. The new hybrid technology, which Audi already uses in some production models, saves roughly two kilograms (4.41 lb) per wheel. The wheels of the A2 concept combine the blade look of the e-tron family with Audi’s classic spoke design.