Abstract:
A method and a device for operating a vehicle provide a convenient and flexible function for limiting a performance quantity, in particular the speed or the engine speed of the vehicle. At least one limiting value is predefined for the performance quantity. The at least one limiting value is predefined at an input unit as a function of at least one criterion. A check is made to determine whether the at least one criterion is satisfied. The at least one limiting value is activated if the at least one criterion is satisfied.

Description:
BACKGROUND INFORMATION  
       [0001]     Limiting a performance quantity of a vehicle, in particular the speed or engine speed, to a predefined limiting value is known. Speed limiters, for example, are now used in the following situations: for maximum speed limitation, for limiting the speed in vehicles whose center of gravity may vary due to an air suspension, for variable speed limitation, which is set and activated by the driver via an operating element.  
       SUMMARY OF THE INVENTION  
       [0002]     The method according to the present invention and the device according to the present invention for operating a vehicle have the advantage over the related art that the at least one limiting value is predefined at an input unit as a function of at least one criterion; it is checked whether the at least one criterion is satisfied; and the at least one limiting value is activated if the at least one criterion is satisfied. This makes it possible to extend the function of limiting the performance quantity of the vehicle, the speed limiting function in particular, in such a way that a more flexible configuration of the limiting function is implementable. This substantially increases the application possibilities of the limiting function.  
         [0003]     It is particularly advantageous if an access authorization is selected as the at least one criterion, and if permission is granted for predefining the at least one limiting value only to a holder of a valid access authorization. This makes it possible to limit the maximum speed of the vehicle differently for different users, for example, the individual users having no access to the speed limitation if they have no access authorization. The vehicle&#39;s owner having corresponding access authorization, for example, may thus limit the maximum speed differently when allowing the vehicle to be driven by different users. For example, the owner of a sports car may place the vehicle at the disposal of other users with limitations in terms of the maximum possible speed. The maximum speed of a company car, for example, may also be limited for the individual users to prevent it from being overloaded.  
         [0004]     A further advantage results if a user ID is selected as the at least one criterion. This permits the vehicle speed to be limited differently for different users as described above.  
         [0005]     A further advantage results if a mileage of the vehicle is selected as the at least one criterion. This permits the speed or the engine speed of the vehicle to be limited, in particular when the vehicle or its engine is new, i.e., has covered less than 3000 km. The driver comfort is thus enhanced, because the driver does not need to pay attention to conditions that apply during run-in of the vehicle, i.e., in particular the condition that a predefined engine speed or vehicle speed must not be exceeded.  
         [0006]     A further advantage results if an engine temperature or a variable derived therefrom is selected as the at least one criterion. This protects the vehicle&#39;s engine after starting if the engine is cold without the driver having to pay attention to the engine speed limit or the vehicle speed limit. The ride comfort is thus also enhanced.  
         [0007]     It is furthermore advantageous if the limitation of the performance quantity is canceled via an appropriate input at the input unit. This provides the driver with the option of turning off the limitation function again, giving the limitation function maximum flexibility according to the driver&#39;s needs.  
         [0008]     Another advantage results if the cancellation of the limitation is only allowed to the holder of a valid access authorization. This permits the group of users who are allowed to cancel the limitation function to be predefined, making it possible for users of the vehicle to be prevented from canceling the limitation function.  
         [0009]     A further advantage results if the at least one criterion is encoded in a vehicle key. This permits a speed or engine speed profile to be predefined and encoded in the vehicle key for the particular vehicle user who has the vehicle key, so that the appropriate profile is activated when the vehicle key is inserted into the vehicle lock or the ignition lock. This also represents a convenient approach, which requires no additional action from the driver.  
         [0010]     A further advantage results if a variation of the at least one limiting value is allowed within a predefined range at the input unit as a function of a user ID. This allows the at least one limiting value to be varied within predefined limits for individual users who have no access authorization, so that the scope of function of the limiting function is also increased for these users. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  shows a functional diagram for explaining the method of the present invention and the device of the present invention according to a first exemplary embodiment.  
         [0012]      FIG. 2  shows a functional diagram for explaining the method of the present invention and the device of the present invention according to a second exemplary embodiment.  
         [0013]      FIG. 3  shows a functional diagram for explaining the method of the present invention and the device of the present invention according to a third exemplary embodiment.  
         [0014]      FIG. 4  shows a functional diagram for explaining the method of the present invention and the device of the present invention according to a fourth exemplary embodiment. 
     
    
     DETAILED DESCRIPTION  
       [0015]     In  FIG. 1 , a device according to the present invention for limiting a vehicle performance quantity, in this case the vehicle speed, is labeled as  5 . Device  5  includes an input unit  1  having a first input device  25 , a second input device  30 , a third input device  35 , and a fourth input device  40 . The four input devices  25 ,  30 ,  35 ,  40  may be formed by a single alphanumeric keyboard, for example, and are illustrated in  FIG. 1  separately only for the purposes of the explanation. First input device  25  and third input device  35  may also be card slots or a single card slot for insertion of an access authorization card and/or a user ID card. A second verification unit  45 , which is also connected to an access authorization memory  65  and triggers a first switch  50 , is connected to first input device  25 . Second input device  30  is connectable to a predefinition memory  60  via first switch  50 ; predefinition memory  60  is in turn connected to a first verification unit  15 . First verification unit  15  may also receive input made at third input unit device  35 . The output of first verification unit  15  is also connected to activation means, i.e., an activation unit  20 , which may receive input from fourth input device  40  via a second controlled switch  55 , which is also triggered by second verification unit  45 . The output of activation unit  20  is connected to a limiting unit  10  for limiting the performance quantity of the vehicle. This limiting unit  10 , in the present example, is a vehicle speed limiting unit, which may be situated in an engine controller (not illustrated in  FIG. 1 ) of the vehicle. Except for input unit  1 , device  5  may also be implemented as software and/or hardware in the engine controller.  
         [0016]     In the following, it will be assumed, for example, that the vehicle is used by five individuals. A first individual is, for example, the vehicle owner and has an access authorization card or an access authorization code. The vehicle owner may identify himself via first input device  25  by inserting the access authorization card into the corresponding card slot or entering his access authorization code via the keyboard of input unit  1 . First input device  25  in  FIG. 1  is thus used to synchronize the input activity for determining access authorization. The access authorization data stored on the access authorization card or the access authorization code is compared to the corresponding data from access authorization memory  65  in second verification unit  45 . Access authorization data for one or more individuals having access authorization may be stored in access authorization memory  65 . If identical access authorization data or an identical access authorization code is determined in the comparison, second verification unit  45  causes first controlled switch  50  to connect second input device  30  to predefinition memory  60 . In other words, the keyboard of input unit  1  is enabled for programming predefinition memory  60 . This programming may be displayed, for example, on a display device not shown in  FIG. 1  for checking and correcting. A limiting value for the maximum speed may be predefined in predefinition memory  60  for each user of the vehicle if there is sufficient memory space.  
         [0017]     In the example described, a first limiting value of 130 km/h is predefined for a first user ABCDEF; a second limiting value of 150 km/h is predefined for a second user GHIJKL; a third limiting value of 100 km/h is predefined for a third user MNOPQR, and a fourth limiting value of 180 km/h is predefined for a fourth user STUVWX. Further users who are different from the above users, or the vehicle owner himself, may not be assigned any effective speed limitation, so that the maximum speed for these users is only limited by the engine&#39;s power.  
         [0018]     All users of the vehicle must identify themselves before driving off. This is accomplished via third input device  35 . Identification may take place, for example, via a user code to be entered at the keyboard of input unit  1 , via a user ID card to be inserted into a card slot, or by inserting the vehicle key into the vehicle lock or the ignition lock. In the case of the user ID card or vehicle key, the user ID is permanently stored, i.e., encoded, in the user ID card or vehicle key. In programming predefinition memory  60 , the user ID associated with the corresponding limiting value may also be predefined, for example, by entering the user code on the keyboard of input unit  1 , by inserting the user ID card into the card slot, or by inserting the vehicle key of the respective user into a vehicle lock or ignition lock, second input device  30 , which may thus also include a shared card slot or a vehicle lock or an ignition lock, for example, in addition to the keyboard for at least the input of the corresponding limiting value, being symbolically provided for this purpose in  FIG. 1 .  
         [0019]     The user ID input via third input device  35  is then compared in first verification unit  15  with the user IDs stored in predefinition memory  60 . If the user ID of the user wishing to use the vehicle, input at third input device  35  for the purpose of identification, matches a user ID stored in predefinition memory  60 , first verification unit  15  outputs the corresponding limiting value and causes activation unit  20  to forward this limiting value to limiting unit  10  and to activate limiting unit  10  so that the associated limiting value is observed and not exceeded by the vehicle speed. The user of the vehicle may then request the cancellation of the limit on the performance quantity, in this example, on the vehicle speed, via an input at fourth input device  40 . Fourth input device  40  then causes activation unit  20  to deactivate the limiting value for the vehicle speed in effect for the user of the vehicle and cause limiting unit  10  to cancel this limiting value accordingly if second switch  55  is closed. Second switch  55  is closed only if so instructed by second verification unit  45 , i.e., if a valid access authorization has been entered at first input device  25 . A limiting value for the vehicle speed in this example may thus be canceled only if it is enabled by an individual having appropriate access authorization via first input device  25 . The input at fourth input device  40  may also take place via the keyboard of input unit  1 . The access authorization may also be encoded in a vehicle key; first input device  25  may also include a vehicle lock or an ignition lock in this case.  
         [0020]     A user of the vehicle, whose user ID has been positively established in first verification unit  15 , may also vary the limiting value, predefined for this user, within a predefined range at third input device  35  as shown by the dashed arrow in  FIG. 1 . This predefined range may be formed, for example, by the user being able to program any possible limiting value for the maximum speed associated with his user ID in predefinition memory  60 , as long as this limiting value does not exceed the limiting value originally input via second input device  30  by the individual having access authorization. Thus, for example, the user having user ID ABCDEF may program any limiting value that is less than or equal to 130 km/h, assigned to his user ID, in predefinition memory  60 . User IDs not assigned to any limiting value may also have been stored in predefinition memory  60  by the individual having access authorization. If such a user ID is detected in first verification unit  15  after appropriate input of a user at third input device  35 , this user himself may predefine a limiting value for his user ID at third input device  35 , according to dashed arrow in  FIG. 1 ; this limiting value associated to the user ID is then stored in predefinition memory  60  and is activatable as described above. An enable bit may also be stored in predefinition memory  60  by the individual having access authorization for any user ID, allowing the respective user to freely program or modify this limiting value irrespective of a limiting value assigned to this user ID by the individual having access authorization. The individual having access authorization may also assign in predefinition memory  60  defined ranges to different user IDs within which ranges the respective user may vary the limiting value.  
         [0021]     In an alternative embodiment to the first exemplary embodiment described above, the individual having access authorization may also predefine a uniform limiting value for the maximum speed for all users, for example, in the case of a company car, via second input device  30 , this limiting value applying regardless of the user ID and being activated via activation unit  20  at limiting unit  10  via the predefinition of the uniform limiting value by the individual having access authorization positively identified by second verification unit  45 ; in this case, first verification unit  15  and third input device  35  are not needed.  
         [0022]      FIG. 2  shows a functional diagram for a second exemplary embodiment of the present invention, which has essentially the same design as the functional diagram of  FIG. 1  and in which the same reference symbols denote the same elements as in  FIG. 1 . In contrast with the functional diagram of  FIG. 1 , in the second exemplary embodiment of  FIG. 2 , third input device  35  is not provided. Instead, a mileage detector  70 , in the form of an odometer or a mileage counter, for example, is connected to first verification unit  15 ; mileage detector  70  detects the mileage traveled by the vehicle since its first startup and forwards this mileage to first verification unit  15 . Furthermore, in the second embodiment the individual having access authorization may predefine different limiting values for the maximum vehicle speed for different vehicle mileage ranges at second input device  30  if he has been positively identified in second verification unit  45  as the individual having access authorization in the manner described above. According to the example of  FIG. 2 , he initially inputs a first mileage range of 0 to 500 kilometers in predefinition memory  60  and assigns this range a first limiting value for the maximum speed of 120 km/h in predefinition memory  60 . Subsequently he programs a second mileage range of 501 to 1000 kilometers in predefinition memory  60  and assigns it a second limiting value for the maximum speed of 140 km/h in predefinition memory  60 . Subsequently he programs a third mileage range from 1001 to 1500 kilometers in predefinition memory  60  and assigns it a third limiting value for the maximum speed of 160 km/h in predefinition memory  60 . Subsequently he programs a fourth mileage range from 1501 to 2000 kilometers in predefinition memory  60  and assigns it a fourth limiting value for the maximum speed of 180 km/h in predefinition memory  60 . Subsequently he programs a fifth mileage range of over 2000 kilometers in predefinition memory  60  and assigns it a fifth limiting value for the maximum speed of infinity, i.e., no limitation, in predefinition memory  60 . The maximum speed in the fifth mileage range of the vehicle is thus only limited by the vehicle engine power.  
         [0023]     The instantaneous mileage detected by mileage detector  70  is then evaluated in first verification unit  15  and checked to determine within which of the five mileage ranges stored in predefinition memory  60  the instantaneous mileage falls. First verification unit  15  then outputs the limiting value assigned to the corresponding mileage range and forwards it to activation unit  20 , which then causes limiting unit  10  to receive and observe this limiting value, i.e., to activate it. This above-described limitation according to the second exemplary embodiment may also be canceled via fourth input device  40  as described for the first exemplary embodiment. Running-in a new vehicle is facilitated for the driver by the second exemplary embodiment, because typically full power may not initially be requested from a new vehicle. This is ensured automatically by the limitation without the driver having to pay attention to it. As an alternative to assigning a limiting value for the maximum vehicle speed to the corresponding mileage range of the vehicle, a limiting value for the engine speed may also be assigned to the corresponding mileage range of the vehicle.  
         [0024]      FIG. 3  shows a functional diagram for a third exemplary embodiment of the present invention, which has essentially the same design as the functional diagram of  FIG. 2  and  FIG. 1 , and in which the same reference symbols denote the same elements as in  FIG. 1  and  FIG. 2 . In contrast with the functional diagram of  FIG. 1 , in the third exemplary embodiment of  FIG. 3 , third input device  35  is not provided. Instead, a temperature sensor  75  is connected to first verification unit  15  for detecting engine temperature T; temperature sensor  75  detects engine temperature T and forwards it to first verification unit  15 . Furthermore, in the third exemplary embodiment the individual having access authorization may predefine different limiting values for the engine speed of the vehicle for different engine temperature ranges at second input device  30  if he has been positively identified in second verification unit  45  as the individual having access authorization in the manner described above.  
         [0025]     According to the example of  FIG. 3 , he initially inputs a first engine temperature range T below a first engine temperature T 1  in predefinition memory  60  and assigns it a first limiting value for the engine speed of 1500 rpm in predefinition memory  60 . Subsequently he programs a second engine temperature range for engine temperatures T greater than or equal to first engine temperature T 1  and less than second engine temperature T 2 , which is greater than first engine temperature T 1 , in predefinition memory  60  and assigns this second engine temperature range a second limiting value for the engine speed of 2000 rpm in predefinition memory  60 . Subsequently he programs a third engine temperature range for engine temperatures T greater than or equal to second engine temperature T 2  and less than a third engine temperature T 3 , which is greater than second engine temperature T 2 , in predefinition memory  60  and assigns this second engine temperature range a third limiting value for the engine speed of 3000 rpm in predefinition memory  60 . Subsequently he programs a fourth engine temperature range for engine temperatures T greater than or equal to third engine temperature T 3  in predefinition memory  60  and assigns it a fourth limiting value for the engine speed of infinity, i.e., no limitation, in predefinition memory  60 . The maximum engine speed in the fourth engine temperature range of the vehicle is thus only limited by the vehicle engine power.  
         [0026]     The instantaneous oil temperature or, in this example, engine temperature detected by temperature sensor  75 , is then evaluated in first verification unit  15  and checked to determine within which of the four engine temperature ranges stored in predefinition memory  60  the instantaneous engine temperature T falls. First verification unit  15  then outputs the limiting value assigned to the corresponding engine temperature range and forwards it to activation unit  20 , which then causes limiting unit  10  to receive and observe this limiting value, i.e., to activate it. This above-described limitation according to the third exemplary embodiment may also be canceled via fourth input device  40  as described for the first exemplary embodiment. Engine temperature T may be determined, for example, on the basis of the engine oil temperature or the coolant temperature or on the basis of a variable otherwise derived from engine temperature T as known by those skilled in the art. The third exemplary embodiment makes it possible to facilitate driving the vehicle for the driver shortly after a start with a cold engine, because in this case the full driving performance should not be requested in order to reduce exhaust gas emissions and not to overload the engine. This is ensured automatically by the limitation without the driver having to pay attention to it. In particular, in this third exemplary embodiment, it may be provided that any user be allowed to cancel an instantaneous limitation of the engine speed via fourth input device  40  without being authorized by an individual having access authorization. In this case, second switch  55  would be replaced by a closed connection. Should the user, i.e., the driver of the vehicle, not wish to have the limitation function for engine temperature, he may turn it off as described above.  
         [0027]     It is furthermore possible to combine a plurality of or all above-mentioned criteria and have the corresponding combination ranges programmed in predefinition memory  60  by the individual having access authorization positively identified as such by second verification unit  45  and a limiting value assigned for the performance quantity of the vehicle, for example, the maximum speed, to each of these combination ranges. According to a fourth exemplary embodiment according to  FIG. 4 , the criteria of user ID and mileage of the vehicle are linked to form combination ranges. The functional diagram of  FIG. 4  has essentially the same design as the functional diagram of  FIG. 1  with the difference that in addition to the elements of the functional diagram of  FIG. 1 , a mileage detector  70 , connected to first verification unit  15  as in the functional diagram of  FIG. 2 , is provided in the functional diagram of  FIG. 4 . Otherwise the same reference symbols denote the same elements in  FIG. 1  and  FIG. 4 .  
         [0028]     According to the example of  FIG. 4 , the individual having access authorization programs predefinition memory  60  as follows: a first combination range, characterized by user ID A and a mileage s of less than 1000 km, is configured by the individual having access authorization. The individual having access authorization assigns the first combination range a first limiting value for the maximum vehicle speed of 130 km/h in predefinition memory  60 . A second combination range, characterized by user ID A and a mileage s of equal to or greater than 1000 km, is configured by the individual having access authorization. The individual having access authorization assigns the second combination range a second limiting value for the maximum vehicle speed of 160 km/h in predefinition memory  60 . A third combination range, characterized by user ID B and a mileage s of less than 1000 km, is configured by the individual having access authorization. The individual having access authorization assigns the third combination range a third limiting value for the maximum vehicle speed of 130 km/h in predefinition memory  60 . A fourth combination range, characterized by user ID B and a mileage s of equal to or greater than 1000 km, is configured by the individual having access authorization. The individual having access authorization assigns the fourth combination range a fourth limiting value for the maximum vehicle speed of infinity, i.e., no limitation, in predefinition memory  60 . Thus, if user identity A is detected in first verification unit  15  on the basis of an appropriate input at third input device  35  and an instantaneous mileage s of the vehicle is detected by mileage detector  70  in first verification unit  15  to be less than 1000 km, first verification unit  15  determines that all criteria for the first combination range are present.  
         [0029]     First verification unit  15  then outputs the first limiting value assigned to the first combination range for the maximum vehicle speed of 130 km/h and forwards this value to activation unit  20  for implementation and activation in limitation unit  10 , so that the first limiting value may not be exceeded by the vehicle speed. If user identity A is detected in first verification unit  15  on the basis of an appropriate input at third input device  35  and an instantaneous mileage s of the vehicle is detected by mileage detector  70  in first verification unit  15  to be equal to or greater than 1000 km, first verification unit  15  determines that all criteria for the second combination range are present. First verification unit  15  then outputs the second limiting value assigned to the second combination range for the maximum vehicle speed of 160 km/h and forwards this value to activation unit  20  for implementation and activation in limitation unit  10 , so that the second limiting value may not be exceeded by the vehicle speed.  
         [0030]     If user identity B is detected in first verification unit  15  on the basis of an appropriate input at third input device  35  and an instantaneous mileage s of the vehicle is detected by mileage detector  70  in first verification unit  15  to be less than 1000 km, first verification unit  15  determines that all criteria for the third combination range are present. First verification unit  15  then outputs the third limiting value assigned to the third combination range for the maximum vehicle speed of 130 km/h and forwards this value to activation unit  20  for implementation and activation in limitation unit  10 , so that the third limiting value may not be exceeded by the vehicle speed. If user identity B is detected in first verification unit  15  on the basis of an appropriate input at third input device  35  and an instantaneous mileage s of the vehicle is detected by mileage detector  70  in first verification unit  15  to be equal to or greater than 1000 km, first verification unit  15  determines that all criteria for the fourth combination range are present. First verification unit  15  then outputs the fourth limiting value assigned to the fourth combination range for the maximum vehicle speed of infinity and forwards this value to activation unit  20  for implementation and activation in limitation unit  10 , so that the fourth limiting value may not be exceeded by the vehicle speed. The fourth limiting value represents no limitation; therefore, if the fourth combination range is detected, no limitation is to be activated by limiting unit  10 . If first verification unit  15  detects a user ID which is different from the user IDs stored in predefinition memory  60 , none of the combination ranges programmed in predefinition memory  60  is detected in first verification unit  15 , and thus no limitation is activated. This limitation described according to the fourth exemplary embodiment may be canceled via fourth input device  40  as described for the first exemplary embodiment.  
         [0031]     Any performance quantity of the vehicle, such as an engine torque, engine output, a cylinder filling, etc., may also be selected as a vehicle performance quantity to be limited.