December 27, 2001

Convenience Electronics - Fingerprints and Personalisation
AUDI AG, Carsten Woche, Bodyshell Electronics

Personalisation - a definition

Audi offers a host of electronic components besides radios, navigation systems, and telephones.

All these systems have a range of functions and possible settings so that they can be optimally adapted to your needs. But people are not all the same, and if several people use the same vehicle, the facility for adapting functions can easily be transformed from a convenience into the absolute opposite. Things that you have selected and set, which functions are personally agreeable, and what you do not wish to see are an important part of individuality and personality.

The multitude of functions must therefore, to a certain extent, be "tailored" to each person, so that the feeling of convenience of each individual is not compromised by someone else's "wrong" settings. When only a few functions are affected, that may be of secondary importance, but when you have found your seat out of adjustment and your radio set to the wrong station for the "nth" time, the desire for a technical solution becomes justifiable - and, at Audi, we can provide one.

The technical solution

A solution which permits the appropriate appreciation of convenience electronics demands two significant technical capabilities from a personalisation system in a vehicle. It must be able to cope with several drivers and their settings, and it must be able to recognise which of these people is driving.

The first capability is known in computer technology as user management, and principally calls for investment in adequate memory capacity in the electronic control systems.

On the other hand, the second has the ring of profile selection, personal identification numbers (PIN), passwords, chip cards, or any desired combination of these. All the more so as the demand for personal security of information rises dramatically with the introduction of telecommunications and information services in vehicles.

The regular entering of PINs for diverse applications can in no sense be considered a convenience.

A solution to this dilemma is offered by biometric processes; the identification of fingerprints, for example, is one of these. They have the advantage, that they are always available, are difficult to forge, and are unique to every person.

At this point, Audi decided to develop a system based on the recognition of fingerprints. For Audi, this technology provides the best solution with regard to security and user-friendliness for our customers. Because fingerprints are unique to every person, they are like a personal key carried at all times.

The sensor - a fingerprint feeler

The Audi fingerprint feeler recognises this individual identification characteristic. By contacting the feeler with the finger surface, this is recorded, for example, by a capacitive sensor field consisting of 65,000 sensor electrodes. The information obtained is used to create a digitised grey-scale image of the fingerprint. In a fraction of a second, a decision is made on whether the quality of the image is adequate, or whether a further impression is required. Following this, an algorithm for feature filtering and recognition searches for between one and two dozen characteristic features, so-called minutiae.

These line ends, branches, whirls and loops are memorised as vectors with their position and direction, and prohibit reconstruction of the original fingerprint for purposes of manipulation. Next, in a few milliseconds, the characterising data are compared with information stored in a fingerprint database. If the comparison is successful, the vehicle systems can be released for use, in the same way as if a PIN or password had been entered.

The fingerprint-feeler in the Audi personalisation system enables secure and person-related activation of vehicle functions without the need for additional operations in the car.

How the system operates

To make the way clear in which the personalisation system operates, it must be considered in three phases:

  • Access authority
  • Driving authority
  • Personal function release

In the first phase, the vehicle is opened, by a radio key, without the physical use of a key. In this process, the identification number of the key is transmitted to the car. All functions which must be adjusted before the vehicle is entered, e.g. seat, mirror, and similar settings, are set during personalisation phase 1 (key personalisation) to the positions last used with that key.

In the second, driving authority phase, the vehicle is started by pressing the start button. The system checks that an authorised radio key is inside the car. At the same time, the user's fingerprint is evaluated by the fingerprint sensor, which is integrated into the start button, as described above.

In this process, successful identification of the user (personalisation phase 2) has two functions. On the one hand, it releases the person-related data, and on the other, it corrects any errors in personalisation phase 1 resulting from an exchange of keys (key personalisation).

The intelligent linking of today's vehicle-access authority element for a user (key, card) with biometric identification systems will soon be ready for application in the automobile industry.

Functional scope

To make the scope of this innovation clear, let us compare the range of features that can be adjusted. Today, the radio-key memory will set the seat, the mirror, the electric steering column and the air conditioning.

Tomorrow, both radio key and fingerprint will contribute to personalisation. Far beyond today's scope, they will enable the person-related storage of central-locking system settings, of parking-aid parameters, of diverse interior lighting variants, of coming/leaving-home activation/deactivation times, and many others.

In the 'infotainment' sector, the setting of radio, navigation, organiser, e-mail, address book, TV, telephone, telematics, log book (Audi Logbook), internet and other functions will be possible.

And finally for the drive train, control of various adjustments such as motor agility, gear-changing program, air springing and damping, and further driver-assistance systems is not unrealistic.

The process

When the vehicle is started, its person-related settings are reset to those last used by the present driver. Telephone, addresses, e-mails, and telematic services will become accessible. Personal navigation destinations, radio and TV stations will become available, and personal settings will be automatically adopted.

On leaving the vehicle, personal settings will be protected from unauthorised tampering, and the data stored in an internal and /or external memory.

In this way, we offer the customer a multitude of advantages related to his or her comfort and security.

The complexity of actions required when the car is started will be considerably reduced. Keys can be exchanged. PINs cannot be lost or forgotten. Personal settings are protected from unauthorised access by a unique and unmistakable key.

A potential future application of the Audi Personalisation System is a transfer of settings and data from a privately-owned vehicle to a rented or fleet car, so that, at the changeover point, the driver must only enter and drive away.