Some versions of the upcoming new VW Passat Estate, due to arrive in the UK in November, will be offered with radar distance control that is integrated with an emergency braking assistant.
As well as governing speed in cruise-control mode, the radar monitors the road up to 200 metres ahead, at speeds of up to 130mph. It does so even when the cruise control is switched off. If it senses that an impact is imminent, the system reacts ahead of the driver and pre-pressurises the braking system, setting the brake pads against the discs in microseconds, so that they are poised to offer instant response to the driver’s somewhat slower-moving foot. The system also lowers the threshold at which the brake maximising feature cuts in. This subsystem applies maximum stopping power during an emergency stop, rather than braking in proportion to pedal pressure.
All the underlying cleverness was developed by Bosch, which has a three-stage plan for its predictive safety system (PSS) initiative. The current VW offering is just the first stage, which Bosch calls Predictive Brake Assist (PBA). The second stage is called Predictive Collision Warning (PCW), designed to alert drivers to danger with a short burst of braking, a tug from the driver’s seat-belt pre-tensioner, and warning lights and sounds. Presumably a boxing glove will emerge on a spring from the steering wheel if the driver still fails to react after all the above fanfare.
The next step is to have a system that executes an emergency stop even if the driver does sit there like a crash-test dummy. This is called Predictive Emergency Brake (PEB), and looks to be several years away from production at present. Bosch says it will require an automated visual analysis of the situation, as well as radar.
PEB could help a lot: many accidents occur when drivers are not looking at the road ahead, distracted by something inside the vehicle or looking sideways on the approach to a junction or roundabout. As Bosch notes, “A study by the Association of German Insurers shows that almost half of all drivers involved in accidents did not brake at all.”
No doubt the step beyond these three, which Bosch is not yet talking about, will involve taking control of the steering and attempting to swerve around an object that cannot be avoided by braking alone.
Teething troubles with such a system could prove messy, so while it will no doubt be tried in the near-term on the test track, automatic evasive manoeuvring may take years to arrive on the roads for real.