System for harmonizing a motor vehicle's status information between at least two ID transmitters

#This application claims priority from German Patent Application No. DE 10 2005 047 365.2, which was filed on Oct. 4, 2005, and is incorporated herein by reference in its entirety.

#The invention relates to a system for harmonizing a motor vehicle's status information between at least two ID transmitters of a vehicle-accessing device.

#Vehicle-accessing systems have for some time now made increasing use of bidirectional radio connections, alongside unidirectional radio links, between a vehicle and a portable identification (ID) transmitter, with use being made of, inter alia, the possibility of transmitting information concerning the vehicle status, in particular the vehicle's locked/unlocked condition, from the vehicle to the ID transmitter, and displaying and storing it there. The user is thereby enabled to call up the vehicle status last stored in the ID transmitter also outside the receiving range of the transmitter installed in the vehicle. The problem arising here is that, as a rule, only the last used ID transmitter receives the information about the vehicle status because other ID transmitters (an “extra key”, for example) belonging to the vehicle were either not within the vehicle's radio range while the vehicle status was transmitted or, in order to save energy, cannot operate permanently in the receive mode and so cannot receive the vehicle's current status.

#Further details and advantages will be explained with reference to the attached drawing. Shown schematically therein in

#FIG. 1 is a vehicle-accessing device; and in

#FIG. 2 is signal transmitting between ID transmitters.

#In the following description of a preferred embodiment of the present invention the same reference characters are used to identify the same or comparable components.

#FIG. 1 shows a vehicle-accessing device of a motor vehicle 1 comprising a system for harmonizing a motor vehicle's status information S1 between at least two ID transmitters 5, 6, . . . , with which system the vehicle status S1, together with a reference time t1, corresponding to the vehicle status S1, of a vehicle-side control unit 2 can be sent by said unit via at least one transceiver unit 3 to at least one first mobile ID transmitter 5 over a first radio transmission 4 and stored; and the vehicle status S1 can be sent over a second radio transmission 7 from the first ID transmitter 5 to at least one second ID transmitter 6, . . . and stored. Because the ID transmitters are able to establish bidirectional communication with the vehicle, they are basically also able to establish bidirectional communication among each other. Said bidirectional connection between two ID transmitters 5 and 6 can be used for harmonizing the vehicle status S1.

#Communication between the ID transmitters 5, 6, . . . can preferably be activated by a low-frequency radio signal. The low-frequency radio signal can be sent by a vehicle-side low-frequency antenna of the passive accessing system or, also, by means of a low-frequency disruption produced by, for example, a long-wave radio transmitter. At least one ID transmitter 5, 6, can be activated in such a way provided it is located within radio range of the vehicle 1 or of a corresponding disruptive source. What is achieved thereby is that transmission can be initiated automatically by an external activation.