Patent Publication Number: US-2015088404-A1

Title: Motor vehicle comprising a drive device that automatically turns off when a person gets out of the motor vehicle, and corresponding method for the motor vehicle

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is based on and hereby claims priority to International Application No. PCT/EP2013/001154 filed on Apr. 18, 2013 and German Application No. 10 2012 007 836.6 filed on Apr. 19, 2012, the contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     The invention relates to a method for the shutdown of a drive device of a motor vehicle by a control device in the event that a driver of the motor vehicle leaves the latter while the drive device is switched on. The invention also includes a motor vehicle having a drive device, a control device for shutting down the drive device, a detection device for monitoring a presence of a person in the motor vehicle. A drive device means particularly an internal combustion engine, an electric motor or else a hybrid drive. 
     When a driver leaves his motor vehicle, this usually does not result in this automatically changing an operating state of the vehicle. The vehicle remains in the state in which the driver left it. If an internal combustion engine continues to run, the vehicle produces harmful exhaust gases. To reduce fuel consumption in short stopping phases, such as when stopping at a red traffic light, a motor vehicle may be provided with a start/stop system for such cases that stops an internal combustion engine when a stopping phase is detected. Since the driver usually does not leave the motor vehicle in this case, electrical loads of the motor vehicle continue to be operated, that is to say a radio or an air-conditioning installation, for example. In comparable fashion, an internal combustion engine of a hybrid drive is also switched off whenever it is not needed, that is to say including at the beginning of a stopping phase. 
     When a driver now stops the motor vehicle and then alights from it, the internal combustion engine is shut down by a start/stop system in this case too. For the driver, it then appears as though the motor vehicle is already completely shut down and he is able to remove himself from the motor vehicle for an indefinite time. Particularly if electrical loads with a relatively high power requirement continue to be operated (e.g. an air-conditioning installation) in this case, however, there is then the risk that the vehicle will not be able to be started again. If the motor vehicle is an electrically driven vehicle, this case arises particularly quickly. 
     In motor vehicles today, the risk of a driver forgetting to shut down his motor vehicle completely is particularly high for two further reasons. Firstly, in many cases a motor vehicle is no longer started with an ignition key that needs to be inserted into an ignition lock and turned. Instead, it is now often only necessary to push a button as a starting device for starting the motor vehicle. When getting out of a motor vehicle, the driver can therefore forget to push the button again in order to completely shut down the motor vehicle again. Secondly, drive devices today emit particularly little noise. Particularly electric motors produce no noise or only barely audible noise at a standstill. When a driver leaves the motor vehicle, he is thus not reminded by noises from the motor vehicle to shut down the drive device. As already explained, this danger may also exist in the case of a motor vehicle with an internal combustion engine if the latter has a start/stop system or a hybrid drive. 
     In order to improve user convenience for a driver in this respect, a motor vehicle may be provided with a detection device that monitors whether the driver leaves the motor vehicle. In such a case, as soon as the driver leaves the motor vehicle following a trip, both the drive motor and the electrical loads of the motor vehicle are shut down. This increases the economy of operation of the motor vehicle and at the same time reduces the risk of breakdown on account of a discharged battery. The signal from the detection device distinguishes between the presence and the absence of the driver. The detection device therefore has the advantage over a start/stop system that there is express detection of whether the driver is leaving or has left the motor vehicle. 
     Such a detection device is not only advantageous, however. For example, if a driver alights from his motor vehicle while other passengers are still in the motor vehicle, the automatic shutdown of the motor vehicle also shuts down the telephone installation, for example. If a person in the motor vehicle is currently on a telephone call, the telephone connection is therefore interrupted. 
     SUMMARY 
     One possible object is to operate a motor vehicle economically and in a failsafe manner without this resulting in losses of convenience for the occupants. 
     The inventor proposes a method in which a detection device monitors whether the driver is leaving or has left the motor vehicle while the drive device is switched on, and then shuts down the drive device if need be. This is prompted by a control device, which may be part of an engine controller, for example. Following the shutdown of the drive device at least one electrical load continues to be operated if it was still in operation at the time of the shutdown. Such a load is shut down only if the load receives an additional shutdown signal. 
     The proposed method has the advantage that the interests of further passengers remaining in the motor vehicle can now be specifically taken into consideration. When the driver alights from the motor vehicle, only the drive device is shut down when he alights or immediately thereafter. Passengers can continue to use added-convenience loads, that is to say loads that provide a functionality in the motor vehicle that can be used by the passengers. 
     The proposed motor vehicle allows the implementation of the method. In this regard, the motor vehicle has not only the drive device itself and the aforementioned control device for shutting down the drive device but also a detection device for monitoring a presence of a person in the motor vehicle. The detection device may comprise a weight sensor, for example, that is fitted in the driver&#39;s seat. The control device shuts down the drive device if the detection device signals that the driver is leaving or has left the motor vehicle. An electrical switching device of the motor vehicle can specifically shut down at least one predetermined electrical load. However, the switching device is designed so that, following the shutdown of the drive device, it initially continues to operate the at least one predetermined load if said load was in operation at the time of the shutdown, and shuts it down only later if a predetermined additional shutdown criterion is met. 
     The shutdown criterion may particularly be that a signal is produced by a controller that also controls a locking installation for locking a vehicle door. In other words, the shutdown criterion is met when the driver activates the locking device of the motor vehicle. In the event of a locking request from the driver, it is certain that the added-convenience loads in the motor vehicle are also no longer needed and can therefore be shut down. 
     According to another embodiment of the method, the run-on time for added-convenience systems following the shut down of the drive device can be limited by virtue of the shutdown of the drive device prompting a timer to be started and a shutdown signal for the loads that are still in operation to be produced when the timer expires. This advantageously ensures that the power consumption by the added-convenience loads does not exceed a predetermined level. 
     In order to obtain even more precise control over the amount of energy consumed following the shutdown of the drive device, one embodiment of the method provides for the shutdown of the drive device to prompt a measuring device to be started that measures an amount of the energy consumed by the at least one load continuing to be operated, and to produce the shutdown signal when a predetermined maximum value for the measured energy is reached. An even more precise overview is obtained if, instead of the energy consumed by the loads, an electric power drawn from an energy store of the motor vehicle, for example the electric storage battery thereof, is measured directly. 
     It is particularly optimal in reference to energy consumption if the detection device additionally monitors whether, following the shutdown of the drive device, further persons have actually remained in the motor vehicle, and otherwise, if it is thus detected that the motor vehicle is empty, immediately produces the shutdown signal. 
     A particular increase in convenience that is perceived by passengers is when, following the shutdown of the drive device, at least one of the following added-convenience loads continues to be operated: an infotainment system, a telephone installation, a WLAN communication device (WLAN—wireless local area network), an air-conditioning installation, a seat heater, a seat ventilator, a seat massager, a fan of a passenger compartment ventilator. 
     In this case, in order to prevent the energy store of the motor vehicle from being unnecessarily loaded following the shutdown of the drive device, despite the increased convenience, provision may also be made for the switching-on of at least one predetermined electrical load to be blocked after the drive device has been shut down. In other words, only added-convenience loads that are already in operation in the event of shutdown continue to be operated, whereas others cannot be added thereafter. 
     In connection with a telephone installation and a WLAN communication device, an expedient development of the method provides for a communication device, that is to say a GSM radio module (GSM—global system for mobile communications) or a UMTS radio module (UMTS—universal mobile telecommunication system), for example, to check whether there is a telephone connection or a data connection to a communication network during shutdown of the drive device. If no such connection is detected, the communication device can send a shutdown signal to the telephone installation and/or the WLAN communication device, or generally to a data processing installation. This development of the method firstly ensures that no existing communication connections are interrupted. At the same time, it prevents a new connection from being set up following the shutdown of the drive device, which would mean waiting again until this connection is also terminated again by the user. 
     Instead of a check on the active telephone or data connections, provision may also be made for checking only whether there is actually at least one radio network coupling available, i.e. what is known as bonding, where although the mobile radio module is registered on the communication network, an active telephone or data connection is not set up. In that case, passengers in the motor vehicle can continue to be called. 
     In connection with the issue of how it is possible to detect whether the driver is leaving or has left the motor vehicle, many different technical approaches for implementing the detection device can be used. The provision of appropriate sensors makes it possible, by way of example, to check whether a person in the driver&#39;s seat has fastened his seatbelt or has opened the driver&#39;s door, or whether the weight of the person is encumbering an appropriate switch or sensor in the driver&#39;s seat. It is also possible to use the signals from sensors that are also used in a different context, such as those of an alarm installation. By way of example, alarm installations are capable of also detecting the presence of a person in the surroundings of the motor vehicle. 
     One advantageous development of the proposed method even provides for the detection device also to monitor whether a person is present in a predetermined monitoring area again, that is to say whether the driver or another person has returned to the motor vehicle again. For this purpose, it is also possible to use other sensors that cannot be used to detect when the motor vehicle is left, such as sensors that detect the operation of the steering wheel or of a pedal of the motor vehicle. In this case, the development of the method additionally provides for the drive device to be restarted by the control device if the detection device signals that a person is present again. This results in the advantage that the driver can alight for a short time, for example in order to open a garage door or to buy cigarettes, and can then return to the motor vehicle and continue driving without needing to manually restart the automatically shut-down drive device. Since the electrical loads continue to be operated following shutdown in this case, however, passengers can remain in the passenger compartment and use the loads. 
     The proposed motor vehicle may have features that have already been described here in connection with the developments of the method. For this reason, the corresponding developments of the proposed motor vehicle are not explained again here. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other objects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  shows a schematic illustration of a potential embodiment of the proposed motor vehicle according to the invention; and 
         FIG. 2  shows a flowchart relating to a potential embodiment of the proposed method. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 
       FIG. 1  shows a motor vehicle  10  from which a driver  12  has just got out. By way of example, the motor vehicle  10  may be a car. A further passenger  14 , who is currently on a telephone call and to this end is using a telephone  16  that is connected by radio to a telephone installation  18  of the motor vehicle  10 , has remained in the motor vehicle  10 . The telephone  16  has used a telephone installation  18  to set up a communication connection to a communication network (not shown further) of a mobile radio provider. Furthermore, an air-conditioning installation  20  and a seat heater  22  are also running in the motor vehicle  10 . 
     A drive motor  24  of the motor vehicle  10  has been shut down by a control device  26  of the motor vehicle  10  as the driver  12  left the motor vehicle  10 . The drive device  24  may be an internal combustion engine, an electric motor or else a hybrid drive. The control device  26  may be a controller, for example. 
     The absence of the driver  12  has been detected by a detection device  28  that has then sent a corresponding signal to the control device  26 . The detection device  28  may comprise a multiplicity of components that are suited to detecting the absence or the alighting of the driver  12  from the motor vehicle  10 . In this case, it is also possible to resort to devices as are already known per se from the related art in another context for checking the presence of a person. 
     Although the control device  26  has switched off the drive motor  24 , the telephone installation  18 , the air-conditioning installation  20  and the seat heater  22  continue to be operated even after the shutdown of the drive motor  24 . Hence, the telephone connection from the telephone  16  to the mobile radio network is maintained and the passenger  14  also continues to sit in an air-conditioned passenger compartment and on a heated seat. Only when the passenger  14  also alights from the motor vehicle  10  and the driver  12  locks the vehicle doors using an appropriate key or using a remote control, for example, are the telephone installation  18 , the air-conditioning installation  20  and the seat heater  22  also shut down by the control device  26 . 
     The method according to which the drive motor  24  and the added-convenience loads, i.e. the telephone installation  18 , the air-conditioning installation  20  and the seat heater  22 , are switched in the motor vehicle  10  is explained again below with reference to  FIG. 1  and  FIG. 2 . 
     After the driver  12  got into the motor vehicle  10 , he started the drive motor  24  by operating a starting device. By way of example, he pushed a starting button  30  in S 10 , which prompted the control device  26  to start the drive device  24  in S 12  and also to allow a user to activate the added-convenience loads  18 ,  20 ,  22 . 
     After the driver  12 , as shown in  FIG. 1 , has now left the motor vehicle  10 , this is detected by the detection device  28  and, in S 14 , the control device  26  initially shuts down only the drive motor  24 , but not the added-convenience loads  18 ,  20 ,  22 . In S 16 , the detection device  28  monitors whether the driver  12  has returned to the motor vehicle again. If this is the case (+), the drive device  24  is automatically restarted by the control device  26  (S 12 ) after the control device  26  has received the signal about the return of the driver  12  from the detection device  28 . 
     Otherwise, if the detection device  28  continues to signal the absence of the driver  12 , a check is performed in S 18  to determine, by way of example, whether a locking installation  30  has received a locking request, for example from a remote control of the driver  12 , by virtue of the driver  12  having pushed an appropriate button on the remote control. If this is not the case, the check for the return of the driver  12  is repeated (return to S 16 ). If the locking device  30  is intended to lock the motor vehicle  10 , on the other hand, this is signaled by the locking device  30  to the control device  26  too, which then sends a shutdown signal to the added-convenience loads  18 ,  20 ,  22  that are still in operation, these then likewise being shut down in S 20  (OFF). In this case, the control device  26  is thus simultaneously a switching device for shutting down the added-convenience loads  18 ,  20 ,  22 . 
     The concept described can be used for all types of drive (internal combustion engine, hybrid vehicle and electric vehicle). The shutdown of the drive motor after the driver  12  has alighted reduces an energy consumption for the motor vehicle and hence the risk of breakdown. Furthermore, the vehicle is put into a safe state, so that, by way of example, children who have remained in the motor vehicle  10  cannot set the motor vehicle  10  in motion themselves. Since particular added-convenience systems continue to remain active for a run-on time after the ignition has been shut down, the passengers who have remained in the vehicle continue to be provided with a high level of convenience, and active telephone coupling is also not lost. A locking request from the driver can be used to terminate the added-convenience run-on in a specific manner, since there is now a high likelihood that no-one else is using the added-convenience systems in the motor vehicle  10 . 
     The invention has been described in detail with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention covered by the claims which may include the phrase “at least one of A, B and C” as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 69 USPQ2d 1865 (Fed. Cir. 2004).