DE9419006U1 - Biometric door security system - Google Patents

Description

Description

Biometric door security system

The invention relates to the field of door security systems, in particular for house and apartment doors

House and apartment doors are usually secured using mechanical locking systems. This can be done by simply snapping into place and/or locking with a key. Cylinder locking systems are predominant, and new variants are constantly coming onto the market. Doors secured in this way can be opened using a key, but also by switching on an electromechanical door opener. Electromotive locking and unlocking mechanisms are also known for doors with a higher level of security. In recent times, electronic coding has been integrated into mechanical locking systems and sometimes combined with complete building management systems. These systems are generally used in public buildings, hotels, offices or larger residential complexes. The encoded information can be carried by chip or magnetic cards, infrared transmitters, high-frequency transmitters or even the mechanical key itself (Cologne Iron Fair, March 1994). Systems that used electronic coding, some of which was transmitted to the locking system without contact, were also presented at the "Sicherheit 93" trade fair in Zurich.

The common disadvantage of all these systems is that the required keys, code cards, transmitters, etc. can be lost or stolen, thus creating the risk of misuse, while on the other hand the authorized user can no longer access his property.

For this reason, ideas for biometric access controls (linked to the physical characteristics of the authorized person themselves) were developed. The simplest implementation is the conventional door intercom system (control by hearing), which, however, has the disadvantage that a second person must be present to carry out the control. In practice, it has been shown that a lack of comfort and poor transmission quality often lead to habitual use of the door opener, which creates a significant security risk. Nevertheless, this solution has a

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It has become extremely popular in the private sector because it can be installed without much ^effort .

The patent document DE 4009051 describes a biometric access control system that measures the temperature distribution on the face of the person being checked and compares it with a signature previously recorded in the same way.

The published patent application DE 3006677 describes a system that works according to the dactyloscopic principle.

In terms of the principle of operation, the possibility of verifying a person based on their voice has also been described in several publications (e.g. in the patent document EP 0501631).

The common disadvantage of biometric methods is the high IT expenditure required to ensure a usable level of recognition security. This means that so far only expensive and complex solutions have been implemented that are coupled with a computer with high computing power. They are far too expensive for securing house or apartment doors and are therefore unsuitable.

The invention named in claim 1 is based on the problem of combining the advantages of biometric access control with the advantage of compactness and low price of conventional locking systems and thus making them accessible for use in private households. This problem is solved with the features listed in claim 1.

The invention ensures that only the authorized person has personal access to his apartment or house, whereby it is not necessary to carry a key, whether mechanical or electronic. The inventive design of the solution allows for the first time this device to be integrated as a stand-alone unit into any door to be secured without any special effort.

An advantageous embodiment of the invention is specified in claim 2. With the alternative operability using a DTMF code transmitter the function of the locking system is guaranteed even when acute changes in the voice, e.g. due to a bad cold, make speaker recognition difficult.

To satisfy particularly high security requirements, the option provided in claim 3 of additionally entering a coded

information. Apart from the reading device for the data carrier, no additional effort is required.

An even greater increase in security is achieved if the coded information also includes biometric features, as described in claim 4. The data carrier is therefore only valid and effective in connection with the authorized person.

The history function mentioned in claim 5 allows the specialist to help to solve criminal acts. With the coded transmission of a switching command according to claim 6 it is possible to operate remotely arranged locking mechanisms in a tamper-proof manner.

Another convenience feature is mentioned in claim 7. Since means for voice input and output are already available, the storage and retrieval of short spoken messages is possible without additional effort.

An embodiment of the invention is explained in more detail using the block diagram (Figure 1).

The entire device consists of three components: the central unit 1, the microphone/loudspeaker unit 2 and the bell panel 3. The circuit is activated by pressing a button from 1. If several buttons are connected to the bell panel, the button is first selected in the logic gate 4. This transmits the information serially (SIFl) to a signal processor 5. The signal processor then takes over the control of the system and the processing of the voice signals.

First, the code for generating the prompt is retrieved from the program memory 6, converted into an analog signal and output via the loudspeaker in 2. At the same time, the signal supplied by the microphone is digitized and stored in a volatile memory 7, which is cyclically overwritten.

The memory content is read out by the signal processor and checked for the presence of a spoken word using the methods commonly used in automatic speech processing. If such a word is detected, the feature extraction and comparison with the speech patterns stored in the non-volatile memory 8 are carried out. If the distance calculated falls below a first threshold, the speaker is approved as authorized and the unlocking unit is activated. If a second threshold is also exceeded, which is lower than the first, a

Updating the corresponding speech pattern in memory. The threshold values are determined statistically based on the data in the pattern memory.

If no match is found, a second and third attempt is requested. If these are also unsuccessful, the circuit is blocked for 10 minutes before the entire cycle can be restarted.

As an alternative to the code word, it is also possible to send a tone sequence using a commercially available DTMF code transmitter. If the presence of such a signal is detected, the DTMF decoder takes the place of the voice recognition and (depending on the code) releases the unlocking unit or starts a training session.

The training is analogous to word recognition, with the difference that no threshold calculation and unlocking is carried out, but the speech patterns are simply stored in memory for later comparison.

The DTMF code transmitter can also be used to control all other operating modes of the system, such as whether the serial interface SIF3 should be queried for the presence of a valid coded bit sequence, or whether the recording, compression and storage of a spoken message (duration: about 15 s) should be enabled. Eight different users can be trained per memory module 8. If the system is to be used for apartment buildings (e.g. at the entrance door), the number of memory modules only needs to be increased. The signal processor then also selects the module to be addressed by evaluating the signal from gate 4 via a decoder.

In addition to the connection for button 1, three other connections that are routed from the central unit to the outside are functionally important:

- Power supply (12V DC)

- potential-free relay contact for operating the door opener

- Connection cable to the microphone/speaker unit Optionally, two data ports can be used:

- serial interface SIF2 to the remote locking unit to be operated in a coded manner

- serial interface SIF3 for chip card reader or others

The central unit, which implements the entire range of functions, is housed on a circuit board measuring approx. 8 x 8 cm and thus

easy to integrate into standard door security systems, e.g. intercom systems. This makes it possible for the first time to protect even individual doors with a biometric security system at a reasonable cost.

Claims (7)

Protection claims 1. Door security system based on the biometric principle of speaker verification, characterized in that the speaker verification device is designed as a compact stand-alone unit which, due to its small dimensions, can be integrated into commercially available electromechanical door locking systems. 2. Door security system according to claim 1, characterized in that, as an alternative to speech, a sequence of numbers encoded by means of a dual-tone multi-frequency dialing method (DTMF) can also be acoustically evaluated. 3. Door security system according to claim 1 and 2, characterized in that in addition to speech or DTMF code, other encrypted information can be read into the speaker verification unit, processed and used to legitimize the user. 4. Door security system according to claim 3, characterized in that the encrypted information is the characteristic speech characteristics of the authorized person. 5. Door security system according to claims 1 to 3, characterized in that a certain number of previous opening attempts are logged in a non-volatile memory. 6. Door security system according to claims 1 to 3, characterized in that the speaker verification unit can communicate with a unit used for unlocking via a data line and the unlocking mechanism is only actuated when a valid code has been recognized. 7. Door security system according to claims 1 to 3, characterized in that means are present in the verification unit to store a short spoken message which can be issued to the authorized person after legitimation.