Radar braking system waits for approval for use in NZ

By ALASTAIR SLOANE

Mercedes-Benz is on the verge of introducing its Distronic electronic braking system to New Zealand.

It is waiting for the Australian Government to approve Distronic-equipped S-Class cars.

Once that happens, New Zealand authorities are expected to give Mercedes-Benz the green light.

Distronic is a radar system that monitors the distance to the vehicle in front.

Basically, the frequency the system operates on must be cleared so it doesn't interfere with other electronic transmissions.

"The appearance of Distronic here depends on how quickly the relevant authorities move," said Mercedes-Benz spokesman Martyn Dawson.

"We are talking to government bodies now. Once use of Distronic in Australia is cleared, we can move. We have had a number of requests from S-Class owners for it."

The Australian connection has nothing to do with New Zealand frequency regulations.

It's just that Mercedes-Benz in Germany wants Distronic-equipped cars destined for the Down Under market to meet Australian Design Rule requirements.

Most of the cars Mercedes-Benz imports to New Zealand are built to British requirements. This is why we get many models ahead of Australia.

But Australia is the dominant market in the region and Mercedes-Benz sees no future in building one Distronic-equipped model for New Zealand and one for Australia.

Distronic has been described as an "electronic tow bar." Radar signals from a sensor mounted in the grille constantly measure the distance to the vehicle in front.

A computer processes the data and reacts if necessary. If the Distronic-equipped car is following too closely, it will be gently braked automatically until sufficient distance is restored. In this process, deceleration is limited to one-fifth of the maximum available braking power, so sudden braking is not to be feared. Heavy braking doesn't happen even if the driver in front panic brakes. In this case, Distronic is deactivated, a warning light shows up on the speedometer and an accoustic signal urges the driver to jump on the brakes.

Mercedes-Benz says driving with Distronic is liked being linked to the vehicle in front by a virtual tow bar.

The system is coupled with the car's cruise control and maintains the desired speed. The selected speed ranges from 30 km/h to 180 km/h and is shown on the instrument panel.

If the car gets too close to the car in front, the distance control system is activated.

Distronic is deactivated whenever the driver initiates braking, or whenever the Electronic Stability Programme (ESP) intervenes to prevent skidding.

The distance to the vehicle in front is shown on a scale in the display. However, should the gap narrow to a hazardous degree, the system contents itself with issuing a visual warning and a double audible tone.

This signal can be switched off if it is activated too frequently and becomes annoying in city traffic.

Mercedes-Benz says Distronic's true domain is in smooth flowing motorway traffic, in which the driver can relax and trust in the operation of the radar system.

If traffic becomes more hectic, increased attention is always called for.