Comms, LEDS and imaging drives car electronics

Vehicle-to-vehicle communications, LED headlights and image processing are emerging as the most interesting electronics technologies for car design writes Richard Wilson.

Hella LED rearlight

Hella LED rearlight

Imagine that you are driving along, and a message is projected on your windscreen, warning you of an accident that has just happened around the next corner.

According to the European Commission, this will be soon possible and connected cars, which have wireless links to other vehicles and with road infrastructures are expected to be on European roads next year.

European equipment and communications interface standards for connected cars may now be in place but there are system security issues which need to be addressed by automotive suppliers and the transport industries if connected and autonomous vehicles are to become ubiquitous.

In 2008, the European Commission laid out its plans for the deployment of intelligent transport systems (ITS) in Europe. By 2010, the connected vehicle became a priority for the EU research programmes.

EU-funded research projects have played a major role in the development of the standards, with more than €180m invested in some 40 different projects working on cooperative systems since 2002.

These projects provided their results to ETSI and CEN/ISO, which in turn used them to develop the standards. The EU also funded different operational tests and pilots, as well as standardisation project teams.

Work on the Release 2 standardisation package has already begun to fine tune existing standards and deal with more complex use cases.

Europe hopes there will be international compatibility and it is working with standards organisations in the US and Japan.

“With this set of standards ready, connected cars are on the right track,” says Neelie Kroes, vice-president of the European Commission. “Direct communication between vehicles and infrastructures will ensure safer and more efficient traffic flows, with great benefits for drivers & pedestrians, our environment and our economy.”

The wireless interface standards which will be used in connected cars will be 4G LTE mobile and the 802.11p, which is the variant of the Wi-Fi standard intended for wireless access in moving vehicles. The standard is designed to support data exchange between moving vehicles and between the vehicles and the roadside infrastructure.

It standard uses 10MHz radio channels in the 5.9GHz band (5.850-5.925GHz). This is half the bandwidth, or double the transmission time for a specific data symbol, as used in 802.11a.

As a result the wireless receiver is more immune to signal echoes reflected from other cars or houses, which are likely to be a feature of the radio channel in vehicle-to-vehicle communications.

However, without the necessary broadband communications coverage connecting cars could become more problematic. “For connected cars to really work, we also need more consistency in rules that underpin fast broadband networks,” points out Kroes.

LED headlamps are getting better and more cars are getting them as industry finds its feet with the technology.

The technology with LED headlamps is settling down. Premium cars – the likes of Audi’s A8 and A6 – get projector headlamps. In the mid-range, where cars are starting to get LEDs, less-costly reflector designs are more likely.

Projector headlamps need less frontal area, allowing the bonnet line of a car to be lowered. Car manufacturers are out to create a light shape that is as distinctive as the radiator grilles of old. Audi’s A8 and A6 have 8-10 unique lenses to get their ‘wing’ headlamp shape,

Unlike bulb-based reflector designs, which are constrained by their omni-directional sources where a significant fraction of output has to go straight from the filament to the outside world, LED headlamps can take advantage of their directional sources and reflect every part of the output at least once.

“The LED position is at the side or pointing back into the reflector, and not forward facing. You can control the beam better, and create more interesting reflector shapes. It depends on styling,” said Steffen Pietzonka, v-p of car lighting maker Hella.

Xilinx and Xylon, the supplier of logicbricks customisable embedded development boards, have introduced an automotive driver assistance system (ADAS) design based on the Zynq-7000 All Programmable SoC.

The logiADAK platform comes with evaluation IP cores and a full design framework for camera-based ADAS, with up to six 1Mpixel cameras supported.

Design features include 360 degree surround view with 3D, pedestrian detection indicators, forward camera collision avoidance for pedestrian and vehicle detection and lane departure warning.

“The ability to support up to six one-megapixel cameras is critical for larger sized vehicles, or where it is desirable to combine surround view with forward camera collision avoidance or assist features into a single integrated solution,” said Nick DiFiore, director of Xilinx’s automotive segment.

The Zynq-7000 has processing performance of a dual-core ARM Cortex-A9 MPCore processing system coupled to FPGA logic.

The logiADAK Zynq-7000 All Programmable SoC Automotive Driver Assistance Kit is available through Xylon.

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