Patent Abstract:
The invention concerns a data bus system ( 30 ) including a communication unit ( 40 ) for bidirectional wireless communication with at least one unit ( 20 ) outside of the vehicle ( 10 ) and with vehicle units ( 50, 60, 70, 72, 74, 76, 78, 80, 90, 110, 120, 130, 140 ) which are in data transmission communication with the communication unit ( 40 ) via at least one data bus ( 150, 152, 154 ), wherein data as to status of the vehicle units ( 50, 60, 70, 72, 74, 76, 78, 80, 90, 110, 120, 130, 140 ) is transmitted via the at least one data bus ( 150, 152, 154 ) to the communication unit ( 40 ) and transmittable via the communication unit ( 40 ) to at least one unit ( 20 ) outside the vehicle. According to the invention, a triggering event (E) is received by the vehicle units ( 50, 60, 70, 72, 74, 76, 78, 80, 90, 110, 120, 130, 140 ) via at least one data bus ( 150, 152, 154 ), and the vehicle units ( 50, 60, 70, 72, 74, 76, 78, 80, 90, 110, 120, 130, 140 ) upon receipt of the triggered event (E) transmit their status data via the at least one data bus ( 150, 152, 154 ) to the communication unit ( 40 ).

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The invention concerns a vehicle data bus system of the type set forth in the precharacterizing portion of Patent Claim  1 . 
     2. Related Art of the Invention 
     U.S. Pat. No. 6,028,537 describes a vehicle data bus system wherein signals for control of functions of vehicle devices are receivable from a center via a communication device. 
     SUMMARY OF THE INVENTION 
     It is the task of the invention to provide an improved vehicle data bus system, via which the energy supply in the vehicle battery can be better utilized. 
     The invention solves this task by providing a vehicle data bus system having the characteristics of Patent Claim  1 . 
     Advantageous further developments of the invention are set forth in the dependent claims. 
     It is the basic idea of the invention, that status data is transmitted from bus-networked vehicle devices to the communication device of the vehicle after parking of the vehicle. This concerns in particular all vehicle devices for which status data can be interrogated from outside the vehicle via the communication device. 
     In a preferred embodiment of the invention the communication device is switched to an inactive mode after a certain period of time following parking of the vehicle, wherein it is no longer available for communication. There is also a (concurrent) second predetermined time interval, after the expiration of which the vehicle devices are switched to a so-called “sleep-mode”, in which the energy requirement of the vehicle devices is reduced in comparison to the normal mode. Preferably, the predetermined time interval is longer than the second predetermined time interval. In the time following conclusion of the second predetermined time interval and prior to completion of the predetermined time interval the communication device is available for communication, the vehicle devices are however already in the “sleep-mode”. In this condition it is particularly advantageous, that the status data of all vehicle devices, of which the status data can be interrogated from outside the vehicle via the communication device, is in memory in the communication device. In the case of an interrogation as to status data (data retrieval) from outside, that is, via the communication device, the communication device can answer the interrogation directly on the basis of the stored status data. No activation of the vehicle bus data system is necessary. This preserves the reserve of energy in the vehicle battery and has the consequence that the vehicle in the parked condition has starting-up energy available for a longer period of time. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be now described in greater detail on the basis of the illustrated examples shown in the figures. There is shown: 
         FIG. 1  a schematic representation of the vehicle data bus system, 
         FIG. 2  a schematic representation of a vehicle with a communication link to a unit outside of the vehicle, 
         FIG. 3  a schematic representation of the time sequence illustrating energy management, 
         FIG. 4  a schematic representation of the data exchange relationship, using the example of an independent vehicle heater, 
         FIG. 5  a schematic representation of the data exchange relationship, using the example of a vehicle locking function. 
     
    
    
     Corresponding parts in all figures are provided with the same reference numbers. 
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a schematic representation of a vehicle data bus system  30  with a communication unit  40 . The vehicle data bus system  30  shown in  FIG. 1  includes a gateway  50 , a “keyless go” unit  60 , door control devices  70 ,  72 ,  74 ,  76 , a signal acquisition and control module  78 , an ignition switch control device  80 , a roof operating unit  90 , a independent vehicle heater  100 , a seat heater  110 , an energy control device  120 , a display and operation unit  130 , an instrument cluster (instrument control device)  140  and data buses  150 ,  152 ,  154 . The data bus  150  is for example a CAN class D bus. The data bus  152  is for example a so-called “backbone”, that is, a data bus with very high data transmission rate. The data bus  154  is for example a CAN class B bus or CAN class C bus. The gateway  50  enables data transmission between the various data buses  150 ,  152 ,  154 . The units  40 ,  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140  can individually also be connected via discrete lines or circuits and/or be wireless linked. Also conceivable are mixtures of the topologies, discrete connections and/or data buses. It is likewise conceivable to incorporate various units in a single housing. One or more of the data buses can be in the form of, for example, a ring shaped bus, in particular an optical bus such as, for example, D2B (Domestic Digital Bus) or MOST (Media Oriented Systems Transport). 
     The communication device  40  receives inquires regarding status data from the unit  20 , for example the center, via the communication device  25 . These interrogations of status data are answered by the vehicle  10  using the actual status data of the vehicle units  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140 , in that the inquired about status data are transmitted via the communication device  40  to the unit  20 . 
     Besides this, in the vehicle units  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140  a number of vehicle functions are controllable via control signals which are received by the communication device  40  from the unit  20 , for example, a geographically fixed center. The control signals are transmitted via one or more data buses to the relevant units to be controlled and these carry out the desired actions. 
     The functions in the vehicle devices  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140  include, for example, the locking function for locking of vehicle doors, as well as the trunk lid and the gas fill lid, an independent vehicle heater, as well as air conditioning (climate control), functions for opening and closing windows and the retractable roof, seat heaters, etc. Functions to be carried include for example the opening or closing of windows, the locking of the vehicle, the activation or deactivation of the vehicle independent heater, the deicing of the windshields and/or the ventilation of the vehicle, etc. Besides this, functions to be carried out include the programming of individual functions, for example, programming of a time for activation of the independent vehicle heater, etc. 
       FIG. 2  schematically shows the communication relationship established between a unit  20  and, as an example, a geographically fixed center. 
     A user obtains access to the computer system of the geographically fixed center  20 , for example via the internet  210  using his home computer  240 . Alternatively, or additionally, the user can gain access to the unit  20  via a mobile telephone  260  through a mobile internet, for example WAP (Wireless Application Protocol). Following authentication by the unit  20  the user is associated or connected with a specific vehicle  10 . Via the internet  210  and/or the mobile internet  230  the user can, following authentication, transmit interrogatories for status of vehicle functions to the unit  20 . The unit  20  transmits the request for status data via the communication unit  25  to the vehicle  10 . The vehicle  10  receives the status inquiry via the communication unit  40 . In response, the communication device  40  transmits the requested status data to the unit  20 . 
     In a preferred embodiment of the invention the user can transmit, following authentication, supplemental control instructions to the unit  20  via the internet  210  and/or the mobile internet  230  for remote control of vehicle functions. The unit  20  transmits the control instructions or commands via the communication unit  25  to the vehicle  10 . The vehicle  10  receives the control instructions via the communication unit  40 . In a preferred embodiment of the invention, after receipt of the control signals in the vehicle  10  it is checked whether the energy stored in the vehicle battery is sufficient to carry out the requested functions. If sufficient energy remains available in the battery, then the function is carried out and the appropriate response is transmitted via the communication device  40  to the unit  20 . If it is determined in the vehicle  10  that the energy reserve in the battery is not sufficient to carry out the requested function and/or the energy reserve following the carrying out of the requested function would lie below a predetermined threshold, then the function is not carried out and an appropriate reply is transmitted via the communication unit  40  to the unit  20 . 
     In  FIG. 3  a time sequence showing energy management is schematically represented. Following event E “ignition off” the vehicle units  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140  transmit their status data to the communication device  40 . The communication device  40  then stores the status data received from the vehicle units  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140 . 
     As shown in  FIG. 3 , for a period of time T 1  following the event E “ignition off” a follow-up mode for the communication unit  40  is provided. In the follow-up mode the communication unit  40  continues to remain communication-ready. This means for example that the communication unit  40  continues to remain logged in to a cellular mobile radio network. Following conclusion of time interval T 1  the communication unit  40  switches itself off. In the switched-off mode the communication device  40  is no longer available for communication, that is, it cannot establish a communication link and it is not possible from outside, for example through unit  20  via communication unit  25 , to establish a communication link with the communication unit  40 . A remote control of vehicle functions and/or an interrogation of status data of the vehicle by unit  20  is not possible in the switched-off mode of the communication device  40 . The energy consumption of the communication device  40  in the follow-up mode is higher than in the switched off mode. If the communication unit  40  is kept continuously ready for communication, then the energy supply in the battery would constantly be expended and eventually the vehicle would not be able to start. This is avoided in that, following conclusion of the time interval T 1 , the communication unit  40  is deactivated and thereby its energy consumption is minimized. Preferably the communication unit receives the event E “ignition off” as a signal via the one or more data buses  150 ,  152 ,  154 . 
     In a preferred embodiment of the invention the vehicle units  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140 , following conclusion of the time interval T 2  after the event E “ignition off”, assume a so-called “sleep-mode”. This mode is a mode of the units  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140 , in which energy consumption is reduced in comparison to normal operation. It is also possible thereby to reduce the energy consumption of the vehicle  10 , so that the vehicle while parked maintains readiness to start for longer periods of time. Preferably the vehicle units  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140  receive the event E “ignition off” as a signal via the one or more data buses  150 ,  152 ,  154 . 
     Preferably the vehicle units  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140  go into the sleep-mode also after the carrying out of a remote activated vehicle function. This occurs following a third predetermined time interval T 3  following the conclusion of the carrying out of that function. 
     Preferably the transmission of the data regarding the status of the vehicle units  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140  occurs prior to the end of time interval T 2  following event E. This has the advantage that the receipt of a question regarding status data following conclusion of the time interval T 2 , however prior to conclusion of time interval T 1  after event E, the status data is directly available in the communication unit  40 . The communication unit  40  can thus directly answer a question regarding status data, without having to “wakeup” the vehicle data bus system  30  in its entirety together with units  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140 . This likewise contributes thereto, that the energy supply remaining in the vehicle battery remains available longer in the parked condition of the vehicle  10 . 
     Preferably the communication unit  40  and/or the units  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140  can be awakened by a wakeup signal via the one or more data buses  150 ,  152 ,  154 . Thereby, a waking up of the vehicle data bus system  30  can be ensured, when for example the vehicle  10  is unlocked by a remote control signal from the user and/or the door knob of a vehicle door is operated. 
     Preferably the time interval T 2  is substantially shorter than the time interval T 1 . Thus, the communication readiness of the communication unit  40  is ensured. This can, as required, for example upon receipt of a control signal for a vehicle function, wake up the units  50 ,  60 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80 ,  90 ,  110 ,  120 ,  130 ,  140  via a wakeup signal via the one or more data buses. 
     In a further advantageous embodiment of the invention the unit  120  is connected directly with the communication unit  40 , so that for a status inquiry regarding the energy supply  124  the entire bus system  3  need not be awakened. 
       FIG. 4  shows by way of example the sequence in the vehicle  10 , with the associated data exchange in the vehicle  10 , in the case of the remote control of a vehicle function, namely, vehicle independent heating.  FIG. 5  shows by way of example the sequence in the vehicle  10 , with the associated data exchange in the vehicle  10 , in the case of the remote control of a vehicle function, namely, vehicle locking. The data exchange shown schematically in  FIG. 4  and  FIG. 5  can occur via one or more busses and/or via discrete lines or circuits. The communication between the unit  20  and the communication unit  40  occurs via the communication unit  25 , which is not shown in  FIG. 4  and  FIG. 5 . 
     The data  24 , which is received by the communication unit  40  from the unit  20 , includes, in the example wherein the function is vehicle independent heating as shown in  FIG. 4 , a starting signal for starting the vehicle heater and a stop signal for stopping the vehicle heater, a time signal for setting the starting time of the vehicle independent heater and/or the signal for canceling the start time. From the vehicle  10  the following status data  42  concerning the vehicle independent heater can be transmitted via the communication unit  40  to the unit  20 : status “ignition on”, status “remote control of vehicle independent heater deactivated”, status “energy supply insufficient”, status “client programmed temperature cannot be attained by the desired time” and/or status “service activated”. The data  413  transmitted from the communication device  40  to the display and operating unit  130  includes the signals shown by way of example in  FIG. 4 , with which the condition of the remote control of the independent heater stored most recently in the communication device  40 —“activated” or “deactivated”—can be transmitted to the display and operating unit  130 . The transmitted condition can be output or, as the case may be, displayed in the display and operating unit  130 . The data  134  transmitted from the display and operating unit  130  to the communication unit  40  includes in the illustrated embodiment the status indications, that the user has activated or deactivated the service for remote control of the vehicle independent heater, on the display and operating unit  130 . The data  144  transmitted from the instrument cluster  140 , that is, the instrument control device, to the communication device include in the illustrated embodiment a signal reporting that the temperature desired by the client cannot be achieved. This content or information can be determined for example from the vehicle independent heater or the climate control and be stored in the instrument cluster or instrument combination  140 , from which the signal can then be transmitted to the communication device  40 . The data  410  transmitted from the communication device  40  to the vehicle independent heater  100  can include a signal for immediate activation of the vehicle independent heater, a signal for immediate deactivation of the vehicle independent heater, or a signal for programming a start time for the vehicle independent heater, or a signal for canceling the time for programming the start time for the vehicle heater. The data  140  transmitted from the vehicle independent heater  100  to the communication device  40  is optional and could include for example status data regarding the vehicle independent heater. 
     If the communication unit  40  receives a signal from among the possible signals of data  24  that concern the remote control of the vehicle functions, that is, the received signal includes a signal for control of vehicle functions, then the communication unit  40  transmits the inquiry  412  to the energy control device  120  in order to determine the value  124  of the actual energy reserve in the battery. This value  124  is transmitted from the energy control device  120  to the communication device  40 . In the example shown in  FIG. 4  the inquiry to the energy control device is carried out when the signal  24  which concerns the vehicle independent heater is received. 
     Using the value  124  the communication device  40  determines whether the carrying out of the vehicle function—for example heating with the vehicle independent heater—can be reconciled with the still available energy reserve. If the energy supply in storage does not suffice for carrying out the function or if upon carrying out the function the residual energy supply would drop below a predetermined threshold, then the communication unit makes the decision not to carryout the function. The unit  20  is, beyond this, informed by a status signal “energy supply insufficient” of data  42 . If the stored energy supply is sufficient for carrying out the function and/or if upon carrying out the function the residual energy supply would not drop below a predetermined threshold, then the communication unit makes the decision to carry out the function. The unit  20  is, beyond this, informed by the status signal “service activated” of data  42 . 
     The data  24 , which are received by the communication unit  40  from the unit  20 , include, in the example of the vehicle locking function of  FIG. 5 , a signal for locking the vehicle  10 . From the vehicle  10  the following status data  42  concerning the vehicle locking and the unit  20  is transmitted via the communication device  40 : status “ignition on”, status “vehicle locking deactivated”, status “energy supply insufficient” and/or status “vehicle locked”. The data  413  transmitted from the communication unit  40  to the display and operation unit  130  include, in the example shown in  FIG. 5 , signals as to which condition of the remote control vehicle unlocking device was most recently stored in the communication unit  40 —“activated” or “deactivated”. The transmitted condition can then be output or, as the case may be, displayed in the display and operation unit  130 . The data  134  transmitted from the display and operation unit  130  to the communication device  40  include in the illustrated example the status messages that the user has activated or deactivated the service for remote control vehicle unlocking. These messages are transmitted to the communication device  40 . The data  414  is transmitted to the instrument cluster  140 , that is, the instrument control device, which in the shown example includes the data  414  of the status signal that the vehicle is being operated remotely. From the instrument cluster  140 , that is, the instrument control device, the data  144  are transmitted to the communication unit, in the shown example the data  144  include the status signal as to the status that the vehicle was unlocked remotely, and stored in the combination instrument  140  so that it can as needed be displayed. The data  48  transmitted from the communication unit  40  to the ignition lock control device  80  includes in the shown example of the vehicle locking function a signal for locking the vehicle. In the ignition lock device this signal is converted to signals  870 ,  872 ,  874 ,  876 ,  878 . Respectively one of the signals  870 ,  872 ,  874 ,  876 ,  878  is transmitted to one of the units  70 ,  72 ,  74 ,  76 ,  78 , from which respectively the locking mechanisms for the doors, the trunk lid as well as the gas tank lock, etc. are controlled. The signals  708 ,  728 ,  748 ,  768  and  788  are optional and can include status data of the units  70 ,  72 ,  74 ,  76 ,  78 . The data  84  transmitted from the ignition lock control device  80  to the communication unit  40  is optional and can include for example status data regarding the ignition lock device. 
     If the communication device  40  receives a signal from among the possible signals of data  24  that concern vehicle locking, that is, a signal for control of vehicle functions, then the communication unit  40  sends an inquiry  412  to the energy control device  120 , in order to determine the value  124  of the actual battery reserve or energy supply in the battery. This value  124  is transmitted from the energy control device  120  to the communication unit  40 . In the example shown in  FIG. 5  the inquiry to the energy control device is carried out when the signal  24  concerning vehicle locking is received. 
     Using the value  124  it is determined in the communication device  40  whether the carrying out of the vehicle function—in this example vehicle locking—is reconcilable with the remaining energy supply. If the energy supply in storage is not sufficient for carrying out the function, or if the carrying out of the function would cause the remaining energy supply to drop below a predetermined threshold, then the communication unit arrives at the decision not to carry out the function. The unit  20  is, beyond this, informed of the data  42  by a status signal “energy supply insufficient”. If the remaining energy supply is sufficient for carrying out the function and/or if the carrying out of the function does not cause the residual energy supply to drop below a predetermined threshold, then the communication unit arrives at the decision to carry out the function. The unit  20  is, beyond this, informed of the data  42  by a status signal “vehicle locked”.

Technology Classification (CPC): 6