Volvo pedestrian system fails tests

The latest mishap follows a crash earlier in the year when a Volvo crashed into a truck instead of braking automatically to avoid it.  This time the Pedestrian Detection system failed to trigger as the latest V60 approached a humanoid dummy during a demonstration at Verona in Italy.

The incident also reveals that Volvo engineers discreetly modify the inflatable dummies to ‘trick’ the car’s radar system into detecting a pedestrian.  More than 650 demonstrations passed without incident during the V60 press preview in Italy but things went wrong for the Aussies.

“I am very sad this has happened. We know the technology works, but I am not happy with the demonstration methods we are using," says Jonas Tisell, Volvo’s head of active safety.

Volvo believes the failures, which saw the dummy struck a number of times, occurred because a small plastic panel covered in aluminium foil that sits in a sandbag at the dummy was not installed correctly.  Volvo also suspects a tractor and trailer directly behind the dummy – but some distance away – has confused the pedestrian warning system.

“The radar goes straight through the air-filled plastic dummy so we put some aluminium inside in the sandbag at the dummy’s feet so the radar could detect it,” says Tisell.

“The reflector was not facing exactly the right way and instead the system detected the tractor directly in line of sight in the background.  The camera told the system that there might be a pedestrian there because it detected the shape of a human, but when the radar went to search for it, it only picked up a faint signal for the dummy and got a more solid signal for the tractor.”

Tisell also defends the way the demonstration is run.  “The problem with an inflatable dummy is that it’s plastic and has air inside. The radar needs an echo, it looks for the body mass, and the radar doesn’t bounce off an inflatable dummy."

It cannot see it. It sees through it. So we added a radar reflector – a 10cm piece of plastic covered in aluminium foil – in the sand bag at the feet of the dummy.  The system works on humans. With humans you have a mass the radar can detect.”

Tisell says he has took the place of the test dummy during development of the system, although Volvo does not let journalists repeat the experiment.  “You never know what can happen. Driving towards a human being, if something goes wrong, it will be a very difficult situation to handle,” he says.

Tisell insists there is no need to make any changes to the calibration of the pedestrian warning technology, but Volvo will review its public demonstration procedures for its crash avoidance systems.

The 5000 dummies identical to the one at the centre of the latest bungle – distributed to Volvo dealers worldwide – could be updated with an aluminium belt that will help the system detect the dummy.