DE10129878A1 - Automatic engine shutdown / starter system for motor vehicles and method for its operation - Google Patents

Abstract

The invention relates to an automatic engine shutdown / starter system for motor vehicles and method for its operation, in which a device for measuring the distance and / or the speed difference to relevant objects in the direction of travel, in particular vehicles traveling ahead, is provided and the control device as a function of Prescribed conditions of the distance and / or the differential speed are decisive for the automatic engine shutdown and / or the automatic restart of the engine. For example, the engine is preferably only switched off when the vehicle is stationary and the distance from the vehicle in front, which is costly over a period of time, and the engine is started when the distance or the differential speed from the vehicle in front increases.

Description

The invention relates to an automatic engine shutdown / starter system for Motor vehicles according to the preamble of claim 1 and method for the same Business.

Such an automatic engine shutdown / starter system for motor vehicles is for example from DE-OS 21 58 095, DE-OS 24 47 579, DE-OS 28 03 145, DE 29 45 304 A1, DE 30 13 878 A1, DE 32 16 204 A1, DE 32 27 888 A1, DE 33 43 399 or DE 36 16 086 A1 known. In this case, separate or on the pedals, switches mounted on the coupling in particular are monitored and dependent on determined operating conditions of the vehicle, especially its standstill Switch off or start the engine when the engine is switched off. This always sets control by the driver ahead.

Existing security risks in the event of one of the manual operation of the driver-dependent engine shutdown or the (re) Tempering considered. For example, DE-OS 21 58 095 suggests monitoring the vehicle’s own speed to prevent accidental shutdown of the vehicle To prevent the engine from moving. The slope of the roadway or street becomes Prevention of rolling away after engine shutdown checked. In addition, should  DE-OS 28 03 145 when the engine is switched off, additional power consumers are switched off To protect the battery against discharge or to switch off the engine only be possible when the engine has reached a minimum temperature and the battery charge sufficient, e.g. for later starting. DE 93 09 617 U1 describes also such an engine shutdown / starter system for motor vehicles, the The vehicle's own speed is taken into account. DE 32 27 888 A1 considered additionally the door closing sensors and, depending on this, directs an activation or Deactivation of the automatic engine shutdown / starter system on. DE 32 28 561 deals primarily with the problem of air conditioning as a large consumer such an engine shutdown / starter system for motor vehicles. DE 33 43 399 C2 additionally detects the shift position of an automatic transmission, especially the Neutral.

In addition, a large number of publications on the subject of automatic driving, especially the distance control between in Column-driving vehicles are known, of which, for example, DE 43 12 595 A1, DE 43 35 979 A1, DE 198 04 944 A1 or DE 199 24 255 A1 DE 100 17 279 A1 should be. For this purpose there is a measuring device for measuring the distance and / or the difference in speed to relevant objects in the direction of travel, in particular vehicles driving ahead are provided and will drive at their own speed by regulating the fuel supply, in some cases even by applying the brakes regulated. However, none is associated with automatic driving Engine shutdown or engine starting considered.

DE 198 38 818 A1 describes one controlled from the driver's line of sight Driving control of the motor vehicle, depending on the viewing direction of the In addition to the drive system, the driver also controls engine shutdown and restart becomes. Motor control and then takes place again while driving if necessary, a brake intervention depending on the distance and / or Differential speed to the vehicle in front.

The object of the invention is to supplement the previous automatic Introduce engine shutdown / starter systems for motor vehicles. This task is through solved the features of claim 1. In addition, in claims 2 and 7 suitable methods for the control of these further developed Engine shutdown / starting systems presented. Advantageous further developments are in each case to the subclaims remove.

This is how an automatic engine shutdown / starter system for motor vehicles becomes presented in which a device for measuring the distance and / or Differential speed to relevant objects in the direction of travel, especially those in front Vehicles, is provided and the control device depending on the presence predetermined conditions of the distance and / or the differential speed over automatic engine shutdown or automatic engine restart decides. It is therefore preferably one for automatic Travel control and distance control already used measuring device and this additionally for the control of the engine shutdown and / or Starter system used.

The invention is intended to be explained in more detail below with the aid of exemplary embodiments and figures are explained. Brief description of the figures:

Fig. 1 motor vehicle with automatic engine shutdown / starter system

Fig. 2 Sketch of a vehicle column with the distance and differential speed experienced by the measuring device

Fig. 3 sequence of procedures for engine shutdown and restarting depending on the distance or the differential speed

Fig. 4 increase in the time period T0 until the engine is switched off with increasing average speed ∅v0 of the vehicle F0

Fig. 5 dependence of the time period T0 on the frequency h of engine shutdowns thousand

Fig. 6 dependence of the time period T0 on the time period thousand of the previous shutdowns

Fig. 7 dependence of the time period T1 from the start of the preceding vehicle to the start of the engine

Fig. 8 sketch of the course of the adjustment depending on the time periods Tan and / or cables of a previous shutdown (x-1)

Fig. 1 shows a sketch of the structure of a first automatic engine shutdown / starter system for motor vehicles including relevant input and control variables. A control device 1 , for example a microcontroller for performing the control tasks, is provided which, in addition to a large number of other variables already taken into account in known engine shutdown / starter systems, such as the ignition lock or a separate start / stop button for monitoring the pedals or the intrinsic speed v0 of the vehicle has a device 2 for measuring the distance and / or the differential speed to relevant objects in the direction of travel, in particular vehicles traveling in front. The input variables detected by this device 2 can be illustrated particularly well on the basis of the sketch in FIG. 2. The measuring device 2 of the vehicle F0 thus determines the distance d1 and the differential speed .DELTA.v1 at least from the immediately preceding vehicle F1. However, vehicles F2 ff. Located further ahead are also preferably taken into account, this being done either by detecting the distance d2 and the differential speed Δv2 relative to the vehicle F0 by the measuring device 2 or, if data is exchanged in a vehicle column, also by the vehicle F1 by means of a corresponding one Measuring device 2 take place relative to the vehicle F1 and the control device 1 can take into account this data passed on from the vehicle F1 to the vehicle F0.

In addition, an operating state parameter memory 3 is provided, in which the preceding operating conditions are stored at least for a predetermined period of time T2. The time period T2 is specified directly in time, e.g. as the last x (e.g. 5 to 10) minutes of operation, or depending on other conditions, e.g. the frequency of engine shutdowns (e.g. the last 5 engine shutdowns) (see Fig. 8 ). It is also conceivable to delete this operating state parameter memory 3 when the entire vehicle is deactivated, for example when leaving the vehicle, etc.

From the control device 1 , the ignition 4 or, in particular in the case of diesel vehicles, the fuel supply are then switched off to switch off the engine and, in addition to the ignition 4 and fuel supply, in particular the electric starter 5 is activated in addition to the ignition.

An existing device for measuring the distance and / or the differential speed to relevant objects in the direction of travel for automatic distance and travel speed control of the moving vehicle is used as the measuring device 2 , thereby significantly reducing the additional costs for this automatic engine shutdown / starter system.

The sequence of the different process alternatives is to be explained below with reference to FIGS . 3a to 3d. For the sake of clarity, only the immediately preceding vehicle F1 is considered for the vehicle F0 and the airspeed v1 of the vehicle F1 in FIG. 3a, the airspeed v0 of the vehicle F0 in FIG. 3b and the resulting distance between the vehicles F0 in FIG. 3c and F1 and in Fig. 3d the operating state of the engine or the switching commands of the engine shutdown / starter system outlined.

After a convoy of vehicles F0 and F1, first brakes the vehicle in front Vehicle F1 in t0, the distance control intervenes in t1 and also vehicle F0 is braked. If the vehicle in front F1 comes to a stop in t2 (v1 (t2) = 0), the distance d1 between the vehicles is reduced to d10 until they come to a standstill.

In this respect, this is the subject of automatic driving. At this point, the control for the automatic engine shutdown / starter system starts. Thus, after the motor vehicle F0 has stopped, the distance (d10) to relevant objects in the direction of travel, here the vehicle F1, is detected and the engine is switched off by the control device 1 , provided that this distance d10 does not change for a predetermined period of time T0. In contrast to a pure time control based on the standing of the vehicle, this further development has the advantage that it is only switched off when an immediate journey is actually not possible due to the stationary vehicle F1 standing still. Of course, further parameters can be taken into account here, in particular the parameters of own speed v0 and various switches on the pedals or driving mode selector switches or separate switches for controlling the engine shutdown and / or restart system, which are common in the prior art.

In addition, the engine is preferably only switched off when the distance d10 is smaller than a predetermined maximum distance, since the detection area of the measuring device 2 may be significantly larger than the monitoring area for an automatic engine shutdown / starter system, for which in this example the maximum distance for the immediately preceding vehicle F1 is viewed approximately 10 to 20 meters.

It also monitors that the engine temperature θ is a minimum operating temperature has reached and the battery charge level based on the voltage of the battery Ubatt one Not less than the minimum threshold. Otherwise, as is known, one would Engine shutdown suppressed.

The distance-related control of the engine shutdown / starter system also offers particular advantages for the case of starting or restarting the motor vehicle, in that the measuring device 2 detects the distance to relevant objects or stores the detected value at least after the motor vehicle has stopped. The engine is or is switched off depending on predetermined conditions, for example the distance or even just actuating the ignition key, disengaging or other conditions, conditions with or without a time delay. The control device 1 starts the engine again when this measured distance d10 to the relevant objects increases again, that is to say, for example, the vehicle F1 immediately ahead starts again. In order to prevent starting and switching off too often in column traffic, further conditions and in particular an adaptation of the time period until the engine is switched off or started are provided.

The engine is started again, for example, when the distance d1 to the relevant objects has increased by more than a predetermined minimum distance d11 and / or the differential speed Δv1 to the relevant objects has reached a predetermined minimum differential speed. The minimum distance d11 or the minimum differential speed are preferably changed depending on the distance d10 while the relevant objects are standing and / or the duration of the engine shutdown Taus. In addition, the case yet is outlined one by incipient increase in the distance d1 in t6 onset time window T1 to start the engine in for resisting t6 in Fig. 3c. The starting of the vehicle F0 following the starting in t6 is then again the subject of an automatic driving operation.

The time period T0 until the engine is switched off and the time period until the start-up T1 is preferably changed as a function of parameters of the previous operating history, which are stored in the operating state parameter memory 3 for at least a predetermined duration.

• - die Eigengeschwindigkeit v0 des Fahrzeugs F0
• - die über das Zeitfenster gemittelte Durchschnittsgeschwindigkeit des Fahrzeugs F0
• - Anzahl h von Motorabschaltungen (h(Taus))
• - die Dauer der Motorabschaltungen Taus einzeln und summiert über das Zeitfenster
• - die Dauer der Betriebsphasen des Motors Tan

In this exemplary embodiment (cf. also FIG. 8), the following are preferably recorded as parameters of the previous operating course:

• - The own speed v0 of the vehicle F0
• the average speed of the vehicle F0 averaged over the time window
• - Number h of engine shutdowns (h (thousand))
• - The duration of the engine shutdowns thousand individually and added up over the time window
• - the duration of the operating phases of the Tan engine

The time until the engine is switched off T0 is based on a standard time preferably increased if the speed in a predetermined period of time beforehand v0 of vehicle F1 has exceeded an upper threshold at least once and / or averaged over this period of time exceeds an average speed threshold, the engine at least for a predetermined number of engine shutdowns and / or for more than a predetermined duration of one or all engine shutdowns already was previously switched off within the time period.

In addition, operating state parameter memory 3 parameters, in particular the frequency, the time interval Tan or the duration of phases of the engine shutdown Taus can be recorded at least for a predetermined time duration or number of shutdowns (frequency h of Taus) and the time period until the shutdown To or restart T1 des Motors can be adjusted depending on these parameters. This can be done according to a characteristic field or self-learning based on predetermined rules.

Thus, in particular, the time period T0 (x) until the engine is switched off is increased in FIG. 8 if the time period of the preceding shutdown of Taus (x-1) and / or the engine operation Tan (x-1) is to be predetermined target time periods (T _off / T _an.soll ). In addition to the time span of the previous engine operation Tan (x-1), the duration of the actual travel operation, that is to say with v0> 0, can also be assessed.

The characteristic field as well as the rules for automatically adjusting the time periods To and T1 depend on a variety of parameters and their complexity can not be displayed.

Excerpts 4 to 7 therefore another possible functional dependencies of the adjustment to the time periods are shown to shutdown T0 or T1 for restarting in FIGS..

Thus, FIG. 4, the increase in the time period T0 up to the shutdown of the engine with increasing average speed of the vehicle ∅v0 F0, wherein, the intrinsic speed of the vehicle was averaged F0 over the time window T2. A lower limit T0min and a T0max can be specified, which should not be exceeded or undershot by the self-learning control or in the characteristic field based on all parameters.

FIG. 5 shows a possible dependency of the time T0 on the frequency of engine shutdowns h Toff in the last x minutes of operation. Alternatively, the frequency or duration of the standing of the vehicle F0 without engine shutdown could also be evaluated. In this exemplary embodiment, the time until the engine is switched off is shortened with an increasing number of shutdowns. Depending on the aim of the method, it is also conceivable to just reverse the strategy, namely to increase the time T0 from stopping and measuring the distance to engine shutdown with the frequency of the previous shutdowns in order to avoid frequent engine shutdowns.

A further alternative that can be linked or that is independent is outlined in FIG. 6. There, a dependency of the time period T0 on the time period thousand of the previous shutdowns is used, ie if the engine has been stationary for a relatively long time in the last minutes of operation, the shutdown is in the current case use earlier.

Fig. 7 outlines the dependence of the time period T1 on starting the preceding vehicle (d1 and Δv1 increase from t5) until the engine is started (in t6).

As already explained, the required operating state parameters are each stored beforehand in the memory 3 and the adjustment of the time period until the engine is switched off or restarted T1 is carried out in the control device via a characteristic curve field or self-learning based on predetermined rules.

As relevant objects for distance and / or differential speed measurement are preferably next to the nearest vehicle F1 in the direction of travel a predetermined number of vehicles F2 ff. which are further ahead are also recorded, if the distance d2,. , , to these lies within predetermined limits. The distance and / or the difference in speed to those located in the direction of travel Vehicles F2 ff. Are also used for control purposes. So in a training of the engine if started within the distance limit detected vehicles F1, F2 in the direction of travel except for a predeterminable one Number, for example 1, of the immediately nearest vehicles (F1) all further vehicles in front (F2, ff.) a distance increasing over a threshold (d2,...) or / and a differential speed above one Have minimum differential speed.

On the other hand, for example, the engine is not started if one of those within the Distance limit detected vehicles in the direction of travel (F1, F2,...) a predeterminable number (again in the borderline case 1) of the vehicles further ahead (F2) no distance increasing over a threshold and / or none Differential speed above a minimum differential speed, namely regardless of the changing distance and / or differential speed of the other immediately nearest vehicles, here F1.

Claims (19)

1. Automatic engine shutdown / starter system for motor vehicles a) with measuring devices for determining operating conditions of the motor vehicle and a control device which, depending on the determined operating conditions, brings about an automatic engine shutdown and / or an automatic engine starting, characterized in that b) a measuring device ( 2 ) for measuring the distance (d1, d2,...) and / or the differential speed (Δv1, Δv2,...) to relevant objects in the direction of travel, in particular vehicles in front (F1, F2,... .), is provided and c) the control device ( 1 ) depending on the presence of predetermined conditions of the distance (d1, d2,...) and / or the differential speed (Δv1, Δv2,...) via the automatic engine shutdown and / or the automatic restart of the engine decides. 2. A method of operating an automatic engine shutdown / starter system according to claim 1, characterized in that the measuring device ( 2 ) detects the distance (d10) to relevant objects at least after the motor vehicle has stopped and the control device ( 1 ) shuts off the engine , provided that this distance (d10 = const) does not change for a specified period (T0). 3. The method according to claim 2, characterized in that the motor only is switched off when the distance (d1) is smaller than a predetermined value (d10). 4. The method according to claim 2 or 3, characterized in that the engine is only switched off if also a) the engine temperature (θ) has reached a minimum operating temperature and b) the battery charge level (Ubatt) does not fall below a minimum threshold. 5. The method according to any one of claims 2 to 4, characterized in that the time period (T0 (x)) until the engine is switched off is dependent on parameters of the previous operating history, which are stored in an operating state parameter memory ( 3 ) at least for a predetermined duration (T2 ) are saved. 6. The method according to claim 5, characterized in that the time period (T0) up to the engine shutdown is increased on the basis of a standard time period if in a predetermined period (T2) beforehand a) the speed (v0) of the vehicle (F0) 1. has exceeded an upper threshold at least once and / or 2. averaged over this period (∅V0) exceeds an average speed threshold, or / and b) the engine was previously switched off within the time period (T2) 1. at least for a predetermined number (h (thousand)) of engine shutdowns and / or 2. for more than a predetermined duration of an engine shutdown (Thousand (x-1)> Thousand target) or a predetermined duration of all engine shutdowns (ΣTout (xi)) in the period (T2). 7. A method for controlling an automatic engine shutdown / starter system according to claim 1, characterized in that a) the measuring device ( 2 ) detects the distance (d10) to relevant objects (F1, F2,...) at least after the motor vehicle has stopped, b) the engine is switched off depending on predetermined conditions and c) the control device ( 1 ) then starts the engine again when this distance (d1> d10) or the difference in speed to the relevant objects increases. 8. The method according to claim 7, characterized in that the motor again is started when the distance (d1> d11) to the relevant objects is around has increased more than a predetermined minimum distance (d11). 9. The method according to claim 7, characterized in that the engine again is started when the difference in speed to the relevant objects a predetermined minimum differential speed is reached. 10. The method according to claim 8 or 9, characterized in that the minimum distance or the minimum differential speed are changed depending on a) the distance (d10) during the standing of the relevant objects and / or b) the duration of engine shutdown (Thu (x)). 11. The method according to any one of the preceding claims 2 to 10, characterized in that in the operating state parameter memory ( 3 ) parameters of the previous operation of the engine shutdown / starter system, in particular the frequency (h (thousand)), the time interval (Tan (x-1 , x-2,...)) or the duration (thousand (x-1, x-2,...)) of phases of the engine shutdown at least for a predetermined duration (T2) or number (n) of shutdowns and the time until the engine is switched off (T0 (x)) or restarted (T1 (x)) is adjusted depending on these parameters. 12. The method according to claim 11, characterized in that the control device ( 1 ) adjusts the period of time until the engine is switched off (T0) or restarted (T1) in accordance with a characteristic field as a function of these parameters. 13. The method according to claim 11, characterized in that the control device ( 1 ) adapts self-learning based on predetermined rules the time period (T0, T1) until the engine is switched off or restarted in accordance with these parameters of the previous operation of the engine shutdown / starter system. 14. The method according to any one of the preceding claims 2 to 13, characterized characterized in that the time period (T0 (x), T1 (x)) until shutdown or Restarting the engine increases when the period of the previous one Shutdown (Taus (x-1)) and / or the engine operation (Tan (x-1)) each predetermined Fall below the target time periods (thousand target / tan target). 15. The method according to any one of the preceding claims 2 to 13, characterized characterized that the nearest vehicle as the relevant object (F1) in the direction of travel and the distance (d1) and / or the Differential speed (Δv1) is used to control this. 16. The method according to any one of the preceding claims 2 to 5, characterized characterized that as relevant objects next to the nearest Vehicle (F1) in the direction of travel also a predetermined number preceding vehicles (F2,...) are recorded if the distance (d2,...) increases this is within predetermined limits. 17. The method according to claim 16, characterized in that the engine is started if all of the vehicles (F1) immediately next to each other from the vehicles detected within the distance limit in the direction of travel except for a predeterminable number ( 1 , 2 ,...) vehicles in front (F2,...) have a distance increasing above a threshold and / or a differential speed above a minimum differential speed. 18. The method according to claim 16, characterized in that the engine is not started when a predeterminable number of vehicles further ahead (F2,...) Of the vehicles which are detected within the distance limit in the direction of travel. a) no distance increasing over a threshold or / and b) have no differential speed above a minimum differential speed, c) regardless of the changing distance and / or differential speed of the other immediately nearest vehicles (F1). 19. Use of the device and the method according to one of the preceding Claims for motor vehicles with an existing device for Measurement of the distance and / or the speed of difference to relevant ones Objects in the direction of travel for automatic distance and Cruise speed control of the moving vehicle.