DE19929426A1 - Determining residual distance to be travelled involves computing distance from fuel quantity, current position, stored route, route-specific information using mean consumption figures - Google Patents

Abstract

The method involves determining the distance from the fuel quantity and a determined fuel consumption. Situation-dependent mean consumption figures are determined, a current vehicle position is determined and the residual distance is computed from the fuel quantity, the current position, a stored route and route-specific information. An Independent claim is also included for an arrangement for determining the distance to be travelled by a motor vehicle with a certain fuel supply.

Description

State of the art

The invention relates to a method for determining a with a motor vehicle with a given The remaining distance and a Arrangement for determining a with a motor vehicle a given supply of fuel Remaining distance according to the genre of the independent Claims from.

There are so-called on-board computers for operation in Motor vehicles known, for example from a Fuel supply quantity and a current one Fuel consumption one with the existing one Fuel supply, in the case of internal combustion engines driven motor vehicles so the tank content, Calculate distance that can be covered.

The well-known calculation method causes a strong one The calculated residual distance fluctuates depending on of a current fuel consumption, depending on of fuel consumption from vehicle speed for example a current vehicle speed.  

Next is, for example, from the cover sheet of DE 43 42 594 C2 a method of calculating one with an existing one Amount of fuel that can be covered is the remaining distance which is an average distance traveled per unit of fuel, So the reciprocal bet of an average consumption over one distance traveled is determined in Dependence on current fuel consumption is corrected, with the remaining distance in Dependence of the tank content and the determined mean Travel distance per fuel unit by multiplication is determined.

The calculation method described in DE 43 42 594 C2 is characterized by fluctuations in the calculated Remaining distance depending on a current one Fuel consumption.

Advantages of the invention

The inventive method and the inventive Arrangement with the features of the independent claims have the advantage that one with a Existing supply of remaining distance that can be covered is precisely predictable. In particular, they have the Advantage that fluctuations in the calculated residual distance thereby be significantly reduced that on past Predictions based on fuel consumption measurements the future consumption of fuel on certain Route sections used for the calculation of the remaining distance will.

Of particular advantage is the possibility to Realization of the invention often in motor vehicles  already existing resources like a Vehicle navigation device and an on-board computer to be able to fall back, the invention by minor adjustments / additions to the operating software of the resources mentioned, and thus with little effort, is feasible.

This is particularly advantageous because it requires little effort realizable, is the possibility to determine average consumption values based on road classes. This is just a location, a comparison with a saved card, from it the determination of the traffic class and determination of the current Fuel consumption for the currently used road class required.

Allow a refinement of the distance calculation a detection of vehicle speed and / or load-dependent Average consumption values.

drawings

Embodiments of the invention are in the drawings shown and are explained in more detail below.

Show it

Fig. 1A is a block diagram of a first simple

Fig. 1B of a second preferred embodiment of the device according to the invention,

Fig. 2 by way of example a situation by which the inventive method is explained, and

Fig. 3 is a flowchart of an embodiment of the invention.

Description of the embodiments

Fig. 1A is a block diagram of a first simple embodiment of a device according to the invention, which is designed for carrying out the inventive method.

A device group 20 of the device 10 according to the invention is connected to a first group of means 30 , 40 for generating signals indicating the current location of the vehicle in which the device 10 is installed. Specifically, this is a receiver 30 for receiving signals emitted by satellites, preferably for receiving radio signals emitted by GPS (Global Positioning System) satellites, by means of which the current position of the vehicle can be determined. It is also a distance meter 40 , which detects, for example, pulses emitted by wheel sensors of an anti-lock braking system for vehicle brakes and determines a distance traveled from the number of pulses determined and a known wheel circumference.

In a preferred embodiment ( Fig. 1B) of the invention, the first group of sensors further comprises means for generating signals indicating the state of motion and the orientation of the vehicle with respect to the cardinal points. This is, for example, a rotation rate sensor 35 , by means of which the orientation of the vehicle in which the device is installed with respect to the cardinal points is detected by integration via the detected rotation rate changes. Finally, it is a speedometer 45 which detects, for example, pulses emitted by wheel sensors of an anti-lock braking system for vehicle brakes and determines a vehicle speed from the number of pulses determined per unit of time and a known wheel circumference. In an advantageous development of the device 10, it is provided that speed and distance meters 45 and 40 access the same wheel sensors, in one case a number of pulses per unit of time, in the other case the absolute number of pulses for determining the corresponding speed to be determined or distance is evaluated.

In an advantageous embodiment of the invention, the described first group of sensors 30 , 35 , 40 , 45 is the sensor system of a vehicle navigation device known per se. These sensors 30 , 35 , 40 , 45 and the controller 20 are also referred to below as a fourth means in connection with a determination of a current vehicle position.

Furthermore, a second group of sensors 50 and 55 is connected to the controller 20 , of which a first sensor 50 , also referred to as first means 50 , serves to determine an amount of fuel, in the case of a vehicle driven by an internal combustion engine, an amount of fuel contained in the vehicle tank . In the case of, for example, an electrically driven vehicle, the fuel supply quantity meter is provided, for example, for detecting a quantity of residual energy remaining in an accumulator. Furthermore, the second group of sensors comprises second means in the form of a further sensor 55 for determining an outflow of fuel quantity from the fuel supply, in the case of a fuel quantity supplied to the internal combustion engine in the case of a vehicle operated by an internal combustion engine, and the strength of the electrical current supplied to an electric motor in the case of an electrically driven vehicle .

The second group of sensors is preferably sensors of a likewise known per se On-board computer, according to the preferred embodiment together with the navigation device in a vehicle installed and also with this for data exchange connected is.

Furthermore, at least a first and a second memory 65 are connected to the controller 20 .

The first memory 60 is a memory for a predefined route to be traveled and information describing the route in more detail. The information that describes the route in greater detail is, for example, road classes, such as, for example, the freeway, federal, state, county road, inner-city road, inner-city road with stricter speed limits, etc., which are assigned to different sections of the route. Furthermore, the first memory 60 is provided for storing lengths of the route sections of the route. Thus, in the first memory 60, each section of the entire route is assigned a street class and the length of the respective route section.

The second memory 65 is provided for storing situation-dependent consumable mean values, in the case of the first simplest exemplary embodiment street class-specific mean values.

In the case of the preferred extended exemplary embodiment ( FIG. 1B), consisting of the connection of the navigation device and the on-board computer, a third memory 70 is connected to the controller 20 , in which information from a country or road map, in particular traffic route information, such as information about motorways, Federal, state and district roads, as well as inner-city streets and at least place and street names, are stored in digital form. In the present exemplary embodiment, the third memory 70 is implemented in the form of a CD-ROM drive with an inserted CD-ROM as a data carrier for the map information. However, it can also be provided that the third memory 70 is implemented in the form of a ROM or RAM semiconductor memory. In the latter case of a RAM memory, the stored map information can be updated in a simple manner, for example via a radio link between the navigation device 10 and a control center or also by information transmitted by means of receivable radio signals.

Furthermore, an output unit 80 is connected to the controller 20 of the device 10 , via which a residual distance in the form of a visual display and / or an acoustic output can be output from the current vehicle location with the existing supply of fuel along the predefined route.

In the preferred exemplary embodiment, the output unit 80 is designed in the form of the output unit of the navigation device for displaying and / or acoustically outputting driving instructions. In this way, driving instructions for the vehicle driver are displayed during the actual route guidance process, for example in the form of an arrow indicating the upcoming turn and a remaining distance display until the turn. As an alternative or in addition to the visual output of the driving instructions, an acoustic reproduction of driving instructions is provided, for example in the form "turn right after 100 meters". To generate the driving instructions, the controller 20 has a corresponding generator, not shown and known per se, in the case of an acoustic output of the driving instructions, for example in the form of a speech synthesizer for converting a driving instruction into intelligible language. The output unit 80 also serves to output further information and / or other information indicating the operating state of the vehicle or the device.

Finally, to the controller 20, an input unit 75 with operating elements, such as push buttons 77 or other input means, such. B. knobs, for entering a route to be traveled and this detailed information or, in the case of the preferred embodiment, a navigation target point, and for operating other functions of the device.

The controller 20 , also referred to as the computer 20 , is designed with regard to the present invention

• to determine an average fuel consumption per distance traveled from the signals from the fuel flow sensor 55 and the odometer 40 ,
• - To link the determined average fuel consumption per distance unit with a road class driven during the consumption determination taking into account the stored route and the road classes assigned to the route sections, and the position signals of the GPS receiver 30 , and
• - to determine the with an existing Supply of fuel along a specified route distance remaining from the known Stock level of fuel for road classes determined average fuel consumption, and the length of the sections of the Vehicle location to be traveled and the route Road classes assigned to route sections.

The controller 20 thus forms, together with the fuel flow meter 55, third means for determining average consumption values.

The mode of operation of the described device is explained below using the example of the preferred exemplary embodiment, according to which the device essentially consists of a combination of a navigation device known per se with an on-board computer also known per se, with reference to the flow chart of FIG. 3.

When the device is switched on, the sensors 30 , 35 , 40 , 45 namely the GPS receiver 30 , the rotation rate sensor 35 , the odometer 40 and the speedometer 45 provide information about the state of motion, the orientation and the current position of the vehicle in which the device 10 is operated. The navigation computer of the navigation device, as part of the device, calculates the current vehicle position from the signals from the sensors 35 , 40 and 45 and from the satellite receiver 30 . If necessary, this is corrected by a comparison with the card information stored in the third memory 70 in the sense of a plausibility check. This method is generally known under the term "map matching".

Subsequently or immediately after switching on the device, i.e. simultaneously with the position determination, the driver or driver enters a destination or navigation destination, for example in a known manner by entering the location and street name of the navigation destination letter by letter and / or by selecting them from a destination list via the input unit 75 . Alternatively, the destination entry can also be provided in the form of a marking of the navigation destination on a map displayed on the output unit 80 by means of a controllable cursor or by entering a number, for example a telephone number, which is clearly assigned to the navigation destination.

After entering the driving or navigation destination and determining the current vehicle location, a route calculation from the current vehicle location to the user-defined destination, that is to say the navigation destination, with the aid of the map information stored in the third memory 70 takes place in a navigation computer of the controller 20 automatically or on the explicit request of the vehicle driver. The calculated route is then stored in the first memory 60 together with information characterizing route segments, such as the respective road class and the length of each route segment.

In the simple described exemplary embodiment, it can instead be provided that the information about the travel route and the information characterizing the route sections is entered by the vehicle driver, for example via the operating unit 75 , and is finally stored in the first memory 60 . A further input option can be provided, for example, in the form of traversing the route with an input means, such as a so-called light pen or a controllable cursor, on a map shown on the output unit 80 , the lengths and road classes of the route sections from the map, i.e. the third Memory 70 read out and stored in the first memory together with the route sections.

Subsequently, that is to say after the travel route has been stored in the first memory 60 , the sequence of FIG. 3 begins with step 105 .

In step 110 , the controller reads in the information from the first group of sensors 30 , 35 , 40 and 45 and determines the current vehicle position (step 115 ) from this, possibly taking into account map information for correction, as described above (step 115 ). By subsequently comparing the current vehicle position with the stored route, the section of the route currently traveled and the road class assigned to it are determined (step 120 ). The signals from the fuel quantity flow meter 55 are then read in and from this and from the signals from the distance meter 40 the current fuel consumption V _k for the currently used road class k is determined (step 125 ). An average fuel consumption value V _k stored in the second memory 65 for the currently used road class is preferably in the form of a moving averaging, for example according to the relationship V _{k, new} = pV _{k, old} + (1-p) .V _k , with 0 < p <1, recalculated (step 130 ) and stored in the second memory 65 (step 135 ).

A first counter i, which can only take positive integer values, is then reset to the value 1 and a total value S to the value 0 (step 140 ).

The information from the first group of sensors 30 to 45 is then read out again (step 145 ) and the current vehicle position is determined therefrom (step 150 ).

The length D _{i of} the i-th section of the stored route following the current vehicle location, that is to say the length D _{1 of} the route section on which the current vehicle location is located, is then read out from the first memory 60 (step 155 ). In the case of section D ₁ immediately following the current vehicle position, its length is reduced by the distance of the section that has already been covered. Further, the current route to the section i associated consumables value V _i, ie the first pass V ₁ from the second memory 65 is read out (step 155) is.

The total value S is then increased by the product of the average consumption value V _{i of} the i-th route section and its length, or in the case of i = 1 its remaining length, D _i (step 160 ). The new total value is thus calculated as S _i = S _i-1 + V _i .D _i , where S _{0 was set to 0} in step 145 .

A check is then carried out to determine whether the sum S _i calculated in step 160 is smaller than the supply of operating fluid detected by the sensor 50 (step 165 ). If this is the case, it is checked whether the destination is at the end of the i-th route section (step 190 ). If this is the case, there is a corresponding output, for example with the content "target lies within the remaining distance that can be reached with the supply of fuel" (step 195 ), from which the sequence goes back to step 110 , that is to say the determination of further average consumption values.

If the destination is not at the end of the i-th route section, the counter i is incremented by one unit, that is to say by the value 1 (step 200 ), and the sequence moves to step 155 , in which the values V _i and D _i are read out from the second and the first memories 65 and 60 for the next route section.

If it is determined in step 165 that the sum S is not less than the amount of fuel, the sum is decreased by the value added in step 160 (S _i = S _i-1 -V _i .D _i ) (step 170 ), and then the remaining distance R that can still be covered with the existing supply of fuel according to the relationship

calculated (step 175 ). This is followed by the remaining distance that can be covered by HusgaDe aer, for example with the content "residual distance R", for example in the form of a display on the output unit 80 (step 180 ). Finally, the process proceeds to step 110 , which means that further average consumption values are determined.

The symbols used mean:

In the exemplary embodiment described, it is determined iteratively to cover the amount of fuel required following the current vehicle location based on the following sections of the route:
V _i : average consumption value for an i-th section of the route
D _i : length of an i-th section of the route; for i = 1, if the vehicle location is within the i-th route section, the remaining length of the i-th route section lying in the direction of travel

Remaining distance that can be covered with the existing supply of operating materials
T: fuel supply, for internal combustion engine tank capacity
i, j: integer count variables.

Parallel to the calculation of the distance that can be covered does this in the preferred embodiment of the device included navigation device the driver of the current Vehicle location along the calculated route using visual and / or acoustic driving instructions, for example with the content "at the next intersection turn right "to the navigation destination.

The mode of operation of the device according to the invention and of the method according to the invention is finally described again for the purpose of clarification using a specific example ( FIG. 2).

The route 250 calculated and still to be covered by the navigation device comprises, for example, 7 route sections 255 , 260 , 265 , 270 , 275 , 280 , 285 . The navigation and thus also the route destination 253 is at the end of the seventh route section 285 , the current vehicle location 252 in the first route section, a first section 257 of the first route section 255 having already been covered and a second section 258 of the first route section still to be covered. The first route section 255 is a freeway section for which a first average consumption value V ₁ of, for example, 11 liters of fuel was determined at a distance of 100 km. The second and fourth sections 260 and 270 are, for example, federal highways with determined average consumption values of, for example, V ₂ = V ₄ = 9 l / 100 km. The third and fifth sections 265 and 275 are, for example, ordinary local passages with a permissible maximum speed of 50 km / h, the sixth section 280 a country road section with a speed limit of 80 km / h and, the seventh section 285 of an inner-city speed 30 zone.

The data stored in the second memory 65 for the route sections are

The current supply of fuel is in the case a motor vehicle with a gasoline internal combustion engine 20 liters (l).

If the calculation of the residual distance is now started in this situation, the current vehicle position is determined in steps 145 and 150 after initialization (steps 105 to 140 ), which is assumed to be complete. In step 155 , the length of the first route section 255 , minus the already traveled first section 257 , ie the value D ₁ = 100 km, is read into the controller 20 . Likewise, the average consumption value V ₁ = 11.0 l / 100 km assigned to this first route section 255 is read into the controller 20 . From this, the sum S is calculated according to the relationship S _i = S _i-1 + V _i .D _i with i = 1 to S _l = 11.0 l. Since 11.0 l <20 l (step 165 ) and the destination, the counting variable i is incremented by "1", so that i = 2. Then in step 155 the values D ₂ and V ₂ from the first and the second memory 60 and 65 read out. The sum S is then calculated as S ₂ = 11.0 l + 10 km. 9 l / 100 km = 10.9 l. The procedure continues analogously to section 285 where, since the destination lies within the range of the vehicle (S ₇ = 14.96 l <T = 201), it is determined in step 190 that the destination is at the end of the now current seventh route section 285 lies. This is followed by a corresponding output in step 195 , which indicates that the target can be reached with the existing supply of fuel, and the process finally goes back to step 110 .

If, for example, the fuel supply in the situation shown is only T = 13.0 liters, the fourth run (i = 4) of the calculation in step 165 determines that S ₄ = 13.51 l <13.0 l, whereupon in Step 170 the sum S is reduced by D ₄ .V ₄ to 12.16 l. Then the remaining distance becomes too

so too
R = 121.3 km is calculated. In step 180 , the remaining distance is then displayed either as a numerical value or, for example, as a marking on a road map displayed on the output unit 80 , whereupon the sequence again goes to step 110 .

It is within the meaning of the invention that the average consumption values stored in the second memory 65 are continuously updated, and in addition that average return values for all road classes traveled in the course of the route are determined by continuously returning to step 110 .

To calculate the remaining distance, it is advantageous if, as in the present embodiment, the Average consumption values even after switching off the device remain saved so that immediately after starting a new trip Average consumption values for a new one Residual distance calculation are available.

In contrast, it can also be an advantage if in Average operation values determined during normal operation for example, when the vehicle is heavily loaded, the for example, arranged in the wheel suspension Sensors can be determined, deleted when starting the journey, since they are not for a heavy load on the vehicle are applicable. This is an inappropriately high Remaining distance indicator that turns out to be too small assumed old average consumption values would be avoided.

Furthermore, it can also be provided that mean values for the various street classes are stored in the second memory 65 for different loading and / or load conditions. For example, consumption averages for all street classes
1. for an unladen vehicle,
2. for a partially loaded vehicle,
3. determined for a fully loaded vehicle
and saved. Furthermore, it can also be provided that further sets of average consumption values depending on the road class are stored, for example as a function of an upward and / or downward gradient of a section of the route.

In contrast, in alternative embodiments it can be provided that the average consumption values are determined not as a function of a specific road class, but, for example, as a function of a maximum permissible driving speed assigned to a section of the route, which can be contained, for example, in the information in the map stored in the third memory 70 in the case of, for example, motorways without a speed limit, a target speed of, for example, 150 km / h is assumed as the maximum speed. For this purpose, the average consumption values for certain distinctive speed values, for example for the values 30 km / h, 50 km / h, 80 km / h, 100 km / h, 120 km / h and 150 km / h, are determined and in the second memory 65 filed.

Likewise, the average consumption values can also be dependent one actually on a certain section of the route driven speed or depending on one usual or actually for a section of the route existing traffic load can be determined, whereby for example information about a traffic jam for example by a service provider via a Cellular connection to the one installed in the vehicle Device sent, or for example in the form of according to the RDS-TMC (Radio Data System Traffic Message Channel) standard in the form of coded information broadcast signals transmitted via a suitable on-board receivers can be evaluated.

Claims (6)

1. A method for determining a residual distance that can be covered by a motor vehicle with a predetermined supply of fuel, the residual distance that can be covered by the supply of fuel being determined from the quantity of fuel and determined fuel consumption,
characterized by
that situation-dependent average consumption values (V _k ) are determined ( 110 , 115 , 120 , 125 , 130 , 135 ),
that a current vehicle position is determined ( 145 , 150 ), and that the remaining distance (R) that can be covered is determined from the amount of fuel (T), the average consumption values (V _k ), the current vehicle position, a stored route ( 250 ) to be traveled and route-specific information . 2. The method according to claim 1, characterized in that the average consumption values (V _k ) are determined as a function of the vehicle speed. 3. The method according to claim 1 or 2, characterized in that the average consumption values (V _k ) are determined as a function of the road class of the roads used. 4. The method according to any one of the preceding claims, characterized in that the average consumption values (V _k ) are determined as a function of a traffic load. 5. The method according to any one of the preceding claims, characterized characterized that the route-specific Information on sections of the route drivable Average speeds are. 6. Arrangement for determining a residual distance that can be covered with a motor vehicle with a predetermined supply of operating materials, with

• - first means for determining a quantity of the supply of fuel,
• - second means for determining fuel consumption and
• a computer for determining a residual distance that can be covered from the determined fuel consumption and the fuel supply quantity,

marked by

• - third means ( 55 , 30 , 45 ) for determining situation-dependent average consumption values (V _k ),
• fourth means ( 30 , 35 , 40 , 45 ) for determining a current vehicle position,
• - A first memory ( 60 ) for a route to be traveled ( 250 ) and route-specific information and
• - The computer ( 20 ) is designed to determine the remaining distance (R) that can be covered from the determined average consumption values (V _k ), the route ( 250 ) to be traveled based on the current vehicle location and the route-specific information.