Transmitter-receiver system with (re-)initialization

• US 5,365,225 A
• Filed: 11/18/1991
• Issued: 11/15/1994
• Est. Priority Date: 05/18/1989
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Bachhuber, Anton
• Primary Examiner(s): Horabik, Michael
• Application Number:
  US07/773,635
• Time in Patent Office: 1,093 Days
• Field of Search: 340/825.31, 340/825.69, 340/825.72, 340/825.3, 380/21, 380/28, 380/37, 380/43, 380/48
• US Class Current: 340/5.26
• CPC Class Codes: G07C 2009/00253 dynamically, e.g. variable code - rolling code
• CPC Class Codes: G07C 2009/00769 with data transmission performed by wireless means
• CPC Class Codes: G07C 2209/06 Involving synchronization or resynchronization between transmitter and receiver; reordering of codes
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks
• CPC Class Codes: G07C 9/21 having a variable access code

Abstract

A transmitter-receiver system (FIGS. 1 and 2), which checks the authorization to use an object (O), contains a transmitter (S), which has a transmitting element (SE) as well as one or more transmitter operator control elements (SB), which for their part can trigger the transmitting of coded signals (SI), the code concerning authorization to use the object (O). The transmitter (S) has at least a single transmitter memory (SS) for the storage of data on use authorizations. The receiver (E) has a receiving element (EE), which receives the coded signals transmitted to it, and a receiver memory (ES) for the storage of data for determining the authorization of codes (SI) received, and also a logic circuit (μP), which checks the respectively received code (SI) by means of the data stored in the receiver memory (ES) and, depending on the result of the check actuates a mechanism (ST). For (re-)initialization, the transmitter (S) contains for preparation of a new future code/set of codes (SI) a random generator (Z), which generates a random number (B) by actuation of at least one of the transmitter operator control elements (SB). The transmitter (S) transmits to the receiver (E) an original code (UC) without any dialog taking place automatically and bidirectionally between the transmitter (S) and the receiver (E).

Claims

1. A transmitter-receiver system for checking authorization to use an object;

comprising;

a transmitter having a transmitting element and a first transmitter operator control element which triggers the transmitting of coded signals by the transmitting element, the coded signal representing a code concerning the authorization to use the object, and

the transmitter also having at least one transmitter memory for storage of data regarding the coded signals representing the coded concerning the authorization to use;

a receiver, having a receiving element which receives the coded signals from the transmitter, having a receiver memory for storage of data for determining authorization or non-authorization of the codes received in the coded signals, and having

a logic unit, which checks the received code with the data stored in the receiver memory and, depending on the result of the check, actuates a mechanism on the object;

in (re-)initialization of the system for at least one of matching and rematching a new code transmitted by the transmitter to a code authorized by the receiver, the transmitter having for preparation of the new code a random generator, which generates a random number by actuation of a second transmitter operator control element;

an original code, which establishes one of a starting code and a set of various new codes including the starting code using at least one of the transmitted original code, data formed in the receiver from the original code, and data formed in the transmitter from the original code, the original code being stored in the transmitter memory or in the receiver memory, wherein the random generator generates a random number that is indicative of only a fragment of the original code and, by further actuations of the second operator control element, produces in stages all fragments of the original code,

the transmitter having a logic unit for converting the generated fragments into the original code,

the original code or starting code being established from at least three fragments derived from random numbers generated by the random generator, and

the original code being transmitted unidirectionally from the transmitter to the receiver without any dialogue taking place automatically and bidirectionally between the transmitter and the receiver.

2. The transmitter-receiver system as claimed in claim 1, wherein the system further comprises a display controlled by a clock generator, which display provides a visual prompt for operator prompting during (re-)initializing of a clock for actuation of the second transmitter operator control element, in order during operation of said clock to generate by stages the original code or starting code by means of the random generator.

3. The transmitter-receiver system as claimed in claim 2, wherein the clock generator provides uneven clock time periods, and the display provides the visual prompt in the uneven clock time periods during which a fragment is at least one of generated and transmitted by means of actuation of respective first and second operator control elements.

4. The transmitter-receiver system as claimed in claim 3, wherein the time periods begin after a predetermined delay after the visual prompt, and wherein the time periods are limited to a predetermined maximum duration.

5. The transmitter-receiver system as claimed in claim 1, wherein the transmitter stores at least one of the fragments directly and fragmental values indirectly, said fragmental values being formed from said fragments according to an algorithm, for establishing at least one of the new code and the sets of new codes in transmitter memory, in order to put together said fragments or values to form at least one of the original code and the starting code and the transmit the original code only after an appropriate actuation of the first transmitter operator control element.

6. The transmitter-receiver system as claimed in claim 1, wherein the original code is transmitted in stages, and each stage is triggered by actuation of the first transmitter operator element after generation of a respective fragment.

7. The transmitter-receiver system as claimed in claim 1, wherein with actuation of the first transmitter operator control element, the transmitter transmits the original code as a complete code in a block after generation of all respective fragments.

8. The transmitter-receiver system as claimed in claim 2, wherein the display in the transmitter and a display in the receiver both provide visual information that all the fragments have been generated and transmitted.

9. The transmitter-receiver system as claimed in claim 1, wherein the second transmitter operator control element is used for generating and wherein the first transmitter operator control element is used in normal operation for transmitting the respective code, so that with each actuation of the second transmitter operator control element a fragment is newly generated, and the respectively generated fragment is buffer-stored in the transmitter memory directly, before a next actuation of the second transmitter operator control element.

10. The transmitter-receiver system as claimed in claim 1, wherein in the transmitter an additional code indicating one of initializing and re-initializing, is added to the original code, in order to inform the receiver that an original code is being transmitted.

11. The transmitter-receiver system as claimed in claim 10, wherein one of a fragment of the original code and the entire original code is transmitted directly together with the additional code.

12. The transmitter-receiver system as claimed in claim 2, wherein the clock generator and the display are located in the transmitter, and wherein the display provides a visual prompt for selection of a clock with which the fragments are to be generated by stages.

13. The transmitter-receiver system as claimed in claim 2, wherein the clock generator is located in at least one of the transmitter and the receiver, and the display is located in the receiver, and wherein the display provides a visual prompt for selection of a clock with which an original code fragments is in each case to be transmitted in stages by actuation of the first transmitter operator control element.

14. The transmitter-receiver system as claimed in claim 13, wherein the receiver only carries out the (re-)initialization if an authorized person additionally carries out an additional measure.

15. The transmitter-receiver system as claimed in claim 2, wherein after receiving one of the fragment and the entire original code, a display in the receiver indicates a complete reception.

16. The transmitter-receiver system as claimed in claim 1, wherein after succeeding in the (re-)initializing, the receiver briefly actuates the mechanism as an acknowledgement.

17. The transmitter-receiver system as claimed in claim 1, wherein the at least one of the first and second transmitter operator control elements is a mini-button recessed into a transmitter housing of the transmitter and is only actuatable with a pointed implement.

18. The transmitter-receiver system as claimed in claim 1, wherein the transmitter contains a counter for counting at least one of the overall duration and the number of repeated transmissions of the original code or the fragments, and wherein the counter prevents transmissions as soon as one of a maximum time and maximum number of transmissions has been exceeded.

19. The transmitter-receiver system as claimed in claim 18, wherein after said transmitting of the original code, the transmitter prevents the first transmitter operator control element from effecting further transmitting of the original code.

20. The transmitter-receiver system as claimed in claim 1, wherein during (re-)initializing, at least one of non-conformity with the stipulated clock, non-conformity with the durations stipulated by the clock or the number of transmissions stipulated by the counter effect that at least one of the previously generated fragment and the previously transmitted fragment, or at least one of the previously generated fragments and the previously transmitted fragments, of the original code are no longer used for making up an original code, instead then only one of the previous original code, the starting code, or a continuation code derived therefrom, continues to be used by the transmitter and by the receiver for next codes to be transmitted in normal operation for actuation of the mechanism, provided that such an original code or starting code has previously been one of generated in and entered into the receiver.

21. The transmitter-receiver system as claimed in claim 1, wherein the transmitter has a conversion unit, by means of which the transmitter enciphers one of the original code and the fragments thereof, in order to transmit the original code in enciphered form, and wherein the receiver has a conversion unit, by means of which the receiver forms from the received coded signal one of the undeciphered original code and the starting code.

22. The transmitter-receiver system as claimed in claim 1, wherein the transmitter and the receiver each has a logic unit which in normal operation calculates from case to case a next code to be transmitted on the basis of one of a plurality of algorithms, the next code being one from the set of codes allowed, and wherein the original code includes a specification of the starting code to be used in the future, and a specification of an alternative algorithm to be used in the future.

23. The transmitter-receiver system as claimed in claim 1, wherein the random generator in the transmitter upon appropriate actuation of the second operator control element quickly counts repeatedly from zero to a high number and repeats this counting for as long as and as often as it takes until, by an appropriate actuation of the at least one operator control element, in keeping with a predetermined unrhythmical clock the counting result then reached is generated as a fragment of one of the original code and starting code.

24. The transmitter-receiver system as claimed in claim 23, wherein the duration of a single counting cycle from zero to zero amounts to one tenth of a second at most, and wherein the maximum duration of the respective time period, and consequently the maximum duration which is allowed for the generation of a fragment and consequently for the corresponding actuation of the at least one operator control element, amounts to ten seconds at most.

25. The transmitter-receiver system as claimed in claim 1, wherein in normal operation, when transmitting a respective code for use of the object, the transmitter has a relatively high transmitting power, and wherein when (re-)initializing one of the original code transmitted, codes transmitted, and at least parts thereof, the transmitter transmits with reduced transmitting power such that, during such (re-)initializing, the transmitter is required to be closer to the receiver than during normal operation.

26. The transmitter-receiver system as claimed in claim 2, wherein the display is in the transmitter, and wherein in the transmitter, the transmitting element is operated in normal operation from a power stage with relatively high power, and consequently with relatively high operating current, and in (re-)initialization operation the transmitting element is operated with a relatively low operating current.

27. The transmitter-receiver system as claimed in claim 25, wherein the object is a motor vehicle, wherein the transmitter is an electronic motor vehicle key, wherein the receiver is attached to the motor vehicle, wherein the receiving element of the receiver is fitted in an interior of the motor vehicle, and wherein the reduced transmitting power used for (re-)initializing is too low to be able to (re-)initialize the receiver from outside the motor vehicle.

28. The transmitter-receiver system as claimed in claim 1, wherein the system further comprises a plurality of receivers, and wherein the transmitter transmits an original code to the plurality of receivers for (re-)initialization of respective receivers of the plurality of receivers.

29. The transmitter-receiver system as claimed in claim 1, wherein the system further comprises a plurality of transmitters, and wherein the receiver receives a different original code from different transmitters of the plurality of transmitters.

30. The transmitter-receiver system as claimed in claim 1, wherein the transmitting element is at least one of a VHF antenna, an ultrasonic radiator and an infrared radiator.

31. The transmitter-receiver system as claimed in claim 1, wherein the receiving element is at least one of a VHF receiver, an ultrasonic microphone and an infrared photo-diode.

32. The transmitter-receiver system as claimed in claim 1, wherein the mechanism is a motor vehicle central locking system and wherein the object is a motor vehicle.

33. The transmitter-receiver system as claimed in claim 1, wherein the original code or starting code is derived from a plurality of fragments in the range of five fragments to eight fragments.

34. The transmitter-receiver system as claimed in claim 1, wherein each of the fragments has eight bits.

35. The transmitter-receiver system as claimed in claim 1, wherein the fragments are interleaved with one another.

36. The transmitter-receiver system as claimed in claim 1, wherein the fragments occur in sequence.

37. The transmitter-receiver system as claimed in claim 2, wherein the display is a small lamp.

38. The transmitter-receiver system as claimed in claim 2, wherein the actuation for (re-)initializing the clock occurs by at least one of pressing and releasing the second transmitter operator control element.

39. The transmitter-receiver system as claimed in claim 4, wherein the delay is one second and the maximum duration is three seconds.

40. The transmitter-receiver system as claimed in claim 9, wherein the generated fragment is buffer-stored in reverse.

41. The transmitter-receiver system as claimed in claim 9, wherein the generated fragment is buffer-stored by code-conversion.

42. The transmitter-receiver system as claimed in claim 10, wherein the additional code has six bits.

43. The transmitter-receiver system as claimed in claim 14, wherein the additional measure is engagement of an ignition key with an ignition lock of a motor vehicle and a rotation of the ignition key to a predetermined position, the object being a motor vehicle.

44. The transmitter-receiver system as claimed in claim 23, wherein the random generator counts repeatedly from zero to 255.