Function validation with the Comfort Access robot - BMW Group Plant Munich

Comfort Access was first introduced in the current BMW 3 Series. A small team from Electrics/Electronics Validation in Munich has now developed a special robot to validate its integration.

Vehicles with Comfort Access use three exterior antennae to generate a three-dimensional electromagnetic field around the car. When the driver enters the field, the system recognises the car key. At about 3 metres from the car, it switches the Welcome Light on to illuminate the area outside the driver’s door. At about 1.5 m, the doors unlock – and relock automatically if the driver walks away.

Until now, this special feature has been validated manually, with parameterisation in development alone taking two days per vehicle. The Comfort Access zones and the influence of production processes on them are then checked manually again in the plant, before production begins, taking into account the various country-specific requirements and equipment features, such as trailer couplings. All in all, it is a lengthy process and not always entirely accurate, given the multitude of different functions.

To solve the problem, the BMW Group and the University of Applied Sciences (HTW) in Dresden have developed a measurement robot that autonomously circles the vehicle several times in a pre-defined pattern to determine the strength of the magnetic field at various required points. Attached to the robot is a box containing the car key. The box can be set at different heights to reflect the different ways a driver might carry it: in their hand, their sports bag or a breast pocket, perhaps. As soon as the robot detects the vehicle electronics locking or unlocking the doors, its inbuilt Lidar scanner measures the distance between the key and the vehicle, and surveys the vehicle’s surroundings. The data that is generates goes straight to a central computer, where it is portrayed as a graphic.

The advantages of the system are obvious: “This robot is not only much faster, it’s also more precise. The results we obtain are highly detailed and, most importantly, objective. So we can even start validating the function before the car has its first test-drive,” explains Martin Hilt.