GB2624665A

GB2624665A - A method for determining a current range of a motor vehicle at the beginning of driving by a range-determining device of the motor vehicle, a computer program

Info

Publication number: GB2624665A
Application number: GB2217642.4A
Authority: GB
Inventors: Vakiti Karthik; Goek Alper
Original assignee: Mercedes Benz Group AG
Current assignee: Mercedes Benz Group AG
Priority date: 2022-11-25
Filing date: 2022-11-25
Publication date: 2024-05-29
Also published as: GB202217642D0; DE102023004499A1

Abstract

The present invention relates to a method for determining a current range (26) of a motor vehicle (10) by a range-determining device (12) of the motor vehicle (10), comprising the steps of providing a predefined cold tire pressure value for a tire (20, 22) of the motor vehicle (10) by an electronic computing device (14) of the range-determining device (12);capturing a current cold tire pressure value of the tire (20, 22) by a capturing device (16, 18) of the range-determining device (12); determining a difference between the predefined cold tire pressure value and the current cold tire pressure value by the electronic computing device (14); generating a difference factor (DF) depending on the determined difference by the electronic computing device (14); and determining the current range (26) depending on a predefined range, which is dependent on the predefined cold tire pressure value, and on the difference factor (DF). Furthermore, the present invention relates to a computer program product, a computer-readable storage medium, a range-determining device (12), as well as to a motor vehicle (10).

Description

A method for determining a current range of a motor vehicle at the beginning of driving by a range-determining device of the motor vehicle, a computer program product, a computer-readable storage medium, a range-determining device as well as a corresponding motor vehicle

FIELD OF THE INVENTION

[0001] The present invention relates to the field of automobiles. More specifically, the present invention relates to a method for determining a current range of a motor vehicle at the beginning of driving by a range-determining device of the motor vehicle. Furthermore, the present invention relates to a corresponding computer program product, to a computer-readable storage medium, a range-determining device, as well as to a motor vehicle.

BACKGROUND INFORMATION

[0002] According to the state of the art, it is known that underinflated tires or a total vehicle load has a significant impact on the fuel economy/range of both conventional power train vehicles and at least partially electrically operated motor vehicles. Current onboard mileage or range estimation value, in particular displayed on instrument panel, does not account for tire pressure and/or total load on the motor vehicle in general.

SUMMARY OF THE INVENTION

[0003] It is the object of the present invention to provide a method, a computer program product, a computer-readable storage medium, a range-determining device as well as a motor vehicle, by which a more precise determination of a current range of the motor vehicle is realized.

[0004] This object is solved by a method, a computer program product, a computer-readable storage medium, a range-determining device, as well as a motor vehicle according to the independent claims. Advantageous embodiments are presented in the dependent claims.

[0005] One aspect of the present invention relates to a method for determining a current range of a motor vehicle at the beginning of driving by a range-determining device of the motor vehicle. A predefined value may be provided for a tire pressure such as a cold tire pressure and/or the total load on the motor vehicle at the beginning of driving by an electronic computing device of the range-determining device. A current cold pressure value of the tire and/or the total load on the motor vehicle may be captured at the beginning of driving by a capturing device of the range-determining device. A difference between the predefined cold tire pressure value and the current cold tire pressure value may be determined by the electronic computing device. The electronic computing device may also determine the difference between the predefined normal load value and the current load value. A difference factor may be generated depending on the determined difference by the electronic computing device and the current range may be determined depending on a predefined range, which is dependent on the predefined cold tire pressure value, on the total load or the motor vehicle, and/or on the difference factor.

[0006] Therefore, the presented solution is to determine a deterioration factor (difference factor) based on the total load on the motor vehicle and cold tire pressure deviation from a provided pressure. For example, the final estimated range may be provided as equal to the initial estimated range multiplied by the deterioration factor.

[0007] The deterioration factor may be calculated by using a series of range tests using recommended cold tire pressure, for example from an OEM, with cold tire pressures deviating from recommended cold tire pressure and also from normal load on the motor vehicle to maximum load. The normal load may refer to the equivalent test weight, which is the test weight of the motor vehicle during emissions and/or range tests on the motor vehicle dynamometer.

[0008] A customer of the motor vehicle may know that a low range is expected as the cold tire pressure is lower and/or the load is higher. Therefore, a better estimation or determination of the range is provided, considering a cold tire pressure deviation from a recommended tire pressure and also the load on the motor vehicle.

[0009] According to an embodiment, a current load of the motor vehicle may be taken into account by determining the current range.

[0010] In another embodiment a current cold tire pressure value for each of the tires may be captured and the current range may be determined depending on each of the tire pressure values.

[0011] In another embodiment an average pressure value for all tires may be determined depending on each of the tire pressure values and the current range may be determined depending on the average pressure value.

[0012] According to another embodiment a weighting factor for each of the tires may be provided and the current range may be determined depending on the weighting factor.

[0013] In another embodiment front tires of the motor vehicle have a different weighting factor than rear tires of the motor vehicle. In a different embodiment, one side of tires of the motor vehicle may have a different weighting factor than an opposite side of tires of the motor vehicle.

[0014] In particular, the method is a computer-implemented method. Therefore, another aspect of the present invention relates to a computer program product including program code means for performing a method according to the preceding aspect. The computer program product may also be regarded as a computer program.

[0015] A still further aspect of the present invention relates to a computer-readable storage medium including at least the computer program product according to the preceding aspect.

[0016] A still further aspect of the present invention relates to a range-determining device for a motor vehicle, the range-determining device including at least one electronic computing device and one capturing device, wherein the range-determining device may be configured for performing a method according to the preceding aspect. In particular, the method may be performed by the range-determining device.

[0017] The electronic computing device may include processors, circuits, in particular integrated circuits, or other electronic means for performing a method.

[0018] Furthermore, the present invention relates to a motor vehicle including at least the range-determining device according to the preceding aspect.

[0019] Advantageous forms of the method are to be regarded as advantageous forms of the computer program product, the computer-readable storage medium, the range-determining device, and the motor vehicle. The motor vehicle as well as the range-determining device may include features for performing a method.

[0020] Further advantages, features, and details of the present invention derive from the following description of preferred embodiments as well as from the drawings. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and/or shown in the figures alone can be employed not only in the respectively indicated combination but also in any other combinations or taken alone without leaving the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The novel features and characteristic of the disclosure are set forth in the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and together with the description, serve to explain the disclosed principles. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and/or methods in accordance with embodiments of the present subject matter are now described below, by way of example only, and with reference to the accompanying figures.

[0022] The drawings show in: [0023] Fig. 1 a schematic side view according to an embodiment of a motor vehicle including an embodiment of a range-determining device; and [0024] Fig. 2 a schematic flow chart according to an embodiment of the method.

[0025] In the figures the same elements or elements having the same function are indicated by the same reference signs.

DETAILED DESCRIPTION

[0026] In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0027] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawing and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

[0028] The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion so that a setup, device or method that includes a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus preceded by "comprises" or "comprise" does not or do not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

[0029] In the following detailed description of the embodiment of the disclosure, reference is made to the accompanying drawing that forms part hereof, and in which is shown by way of illustration a specific embodiment in which the disclosure may be practiced. This embodiment is described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

[0030] Fig. 1 shows a schematic side view according to an embodiment of a motor vehicle 10. The motor vehicle 10 includes at least a range-determining device 12, wherein the range-determining device 12 includes at least one electronic computing device 14 and one capturing device 16, 18. According to the shown embodiment, the range-determining device 12 may include a first capturing device 16 and a second capturing device 18. In particular, Fig. 1 shows that the motor vehicle 10 includes tires 20, 22, wherein each tire 20, 22 includes a capturing device 16, 18. In particular, a first tire 20 with the first capturing device 16 is shown and a second tire 22 with the second capturing device 18 is shown. It is obvious that the motor vehicle 10 may include at least four tires 20, 22, and therefore at least four capturing devices 16, 18.

[0031] Furthermore, Fig. 1 shows that a load 24 may also be placed inside of the motor vehicle 10, in particular in a trunk of the motor vehicle 10.

[0032] From the state of the art it is known that the capturing devices 16, 18 may exist in many motor vehicles 10 to monitor real-time tire pressure, and may warn, for example, a user of the motor vehicle 10 on low or high tire pressure. Furthermore, air-ride suspension systems or tires with load sensors may also be used to measure the total load on the motor vehicle 10. The warning may be displayed only, when the tire 20, 22 is above or below a certain percentage of threshold in order to protect the tire 20, 22. For example, if the recommended cold tire pressure is 36 PSI, the warning may be given when the tire pressure is below 32 PSI. Many studies may indicate that intermediate tire pressure, in particular the tire pressure between the OEM recommended cold tire pressure and the lowest threshold for the capturing device 16, 18, and have considerable impact on the range/fuel economy. But the initial range/fuel economy displayed on the dash when the user enters the motor vehicle 10 may be either based on the current usable battery energy for an at least partially electrically operated motor vehicle or the fuel tank level for a combustion engine vehicle, not considering the current cold tire pressure. The present solution is to take into account the cold tire pressure deviation from the recommended cold tire pressure and the total load on the motor vehicle 10, when estimating the range. An additional low range value due to cold tire pressure deviation may be displayed or a correction to the final displayed range value may be made. For electrically operated motor vehicles or partially electrically operated motor vehicles, the initial range may be estimated on the range based on a usable battery energy (UBE). The UBE may be reduced as the motor vehicle 10 and/or the battery ages and hence the initial range also reduces with vehicle and/or battery aging.

[0033] In particular, for example a difference DF, which may also be referred to as the deterioration factor or the difference factor, may be calibrated in a table. Populating a DF lookup table may require running range test cycles. For example, to obtain a base line, a range test with normal vehicle load and the OEM recommended cold tire pressure may need to be run. The range obtained from these tests may be normal range, for example, 350 miles. Since the measured range is the normal range condition for vehicle operation, the deterioration factor will be 1.0. Other combination tests may be run. For example, the cold tire pressure is at 32 PSI and the maximum load. If the range obtained from these tests is 318 miles, for example, which may be referred to as the abnormal range, a deterioration factor may be for example 318/350 = 0.91.

[0034] By running tests with different combination of tire pressure and load, the complete deterioration factor table (DF lookup table) may be populated. To reduce testing effort, a well calibrated vehicle simulation model may be used to develop the DF lookup table, subject to model accuracy. Even though the initial range may bel reduced as the battery ages, the DFs may be derived initially, when the battery is new, and should still be effective throughout the life cycle of the motor vehicle 10.

[0035] In particular, a current tire pressure value for each of the tires 20, 22 may be captured and the current range 26 may be determined depending on each of the cold tire pressure values. In particular, an average pressure value for all tires may be determined depending on each of the tire pressure values and the current range 26 may be determined depending on the average pressure value. Furthermore, a weighting factor for each of the tires 20, 22 may be determined and provided and the current range 26 may be determined depending on the weighting factor. Furthermore, front tires 20, 22 of the motor vehicle 10 may have a different weighting factor than the rear tires 20, 22 of the motor vehicle 10. In particular, it is most likely that not all tires 20, 22 have the same pressure. For example, only three tires may deviate from the recommended tire pressure or all four tires may differ from the recommended tire pressure. The varying lower tire pressure on individual tires 20, 22 may have impact on the tire friction, for example due to weight distribution and drive wheels, and thus varied energy consumption. The impact caused by the different tire pressures on individual tires 20, 22 may also mean that the average tire pressure may be determined with a weighting factor for individual tire locations. The average tire pressure may need to account for this varied impact of the tire pressures. In some embodiments, the varied impact may mean that, based on the vehicle setup, a weighting factor may be given to each tire location, for example, rear tires of rearward vehicle may have a higher weightage. For example, the front tires may have a weighting factor of 0.3 and the rear tires may have a weighting factor of 0.2.

[0036] Fig. 2 shows a schematic flow chart according to an embodiment of the present invention. In particular, in a first step Si the driving cycle starts. In a second step S2, the tire pressure monitoring system, load sensing for determining the load 24, and/or range determination device 12 may be detected to determine if the features and/or systems are active. If not, a third step S3 is provided, wherein no action is provided. If yes, in a fourth step S4 the average tire pressure may calculated. For example, if the tire pressure management system is active with the range determination device 12, the average tire pressure may be determined.

[0037] Furthermore, if the range-determining device 12 is activated, a fifth step 55 may be implemented, wherein the total vehicle load 24 may be measured by the load sensing component. In a sixth step 56 the difference factor DF determined from the fourth step S4 and/or the fifth step 55 from a lookup table may be determined based on the load 24 as well as the tire pressure 28. In a seventh step 57 the initial range may be determined with the difference DF, wherein the difference DF or the difference factor may be in particular provided as a value from the lookup table with different pressure values 28 as well as with different load values 24. During the seventh step S7, the difference DF may be applied to the initial estimated range that may be based on the available energy to operate the motor vehicle 10. For example, the initial estimated range may be based on a usable battery energy (UBE). The UBE may be reduced as the motor vehicle 10 and/or the battery ages and hence the initial range also reduces with vehicle and/or battery aging. After an eighth step S8, the current range 26 may be determined as an output of the seventh step S7 and displayed in the motor vehicle 10.

Reference Signs motor vehicle 12 range-determining device 14 electronic computing device 16 first capturing device 18 second capturing device first tire 22 second tire 24 load 26 current range 28 tire pressure value DE difference S1-S8 steps

Claims

CLAIMS1. A method for determining a current range (26) of a motor vehicle (10) by a range-determining device (12) of the motor vehicle (10), comprising the steps of: - providing a predefined cold tire pressure value for a tire (20, 22) of the motor vehicle (10) by an electronic computing device (14) of the range-determining device (12); - capturing a current pressure value of the tire (20, 22) by a capturing device (16, 18) of the range-determining device (12); - determining a difference between the predefined cold tire pressure value and the current pressure value by the electronic computing device (14); - generating a difference factor (DE) depending on the determined difference by the electronic computing device (14); and - determining the current range (26) depending on a predefined range, which is dependent on the predefined cold tire pressure value, and on the difference factor (DE).
2. The method according to claim 1, characterized in that a current load (24) of the motor vehicle (10) is taken into account by determining the current range (24).
3. The method according to claim 1 or 2, characterized in that a current cold tire pressure value for each of the tires (20, 22) is captured and the current range (24) is determined depending on each of the tire pressure value.
4. The method according to claim 3, characterized in that an average pressure value for all tires (20,22) is determined depending on each of the tire pressure values and the current range (24) is determined depending on the average pressure value.
5. The method according to any one of claims 3 or 4, characterized in that a weighting factor for each of the tires (20, 22) is provided and the current range (26) is determined depending on the weighting factor.
6. The method according to claim 5, characterized in that the front tires (20,22) of the motor vehicle (10) have a different weighting factor than the rear tires (20, 22) of the motor vehicle (10).
7. A computer program product comprising program code means for performing a method according to any one of claims 1 to 6.
8. A computer-readable storage medium, comprising at least the computer program product according to claim 7.
9. A range-determining device (12) for a motor vehicle (10), comprising at least one electronic computing device (14) and one capturing device (16, 18), wherein the range-determining device (12) is configured to perform a method according to any one of claims 1 to 6.
10. A motor vehicle (10) comprising at least the range-determining device (12) according to claim 9.