JP2004003921A - System for storing integrated value of vehicle driven distance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make difficult a fraudulent manipulation in a driving distance integral stored, in a vehicle driven distance integrated value storage system for storing the driving distance integrated value of a vehicle. <P>SOLUTION: The driving distance integrated value of a vehicle is dispersed and stored, at not only an EEPROM 11 of an ECU 10 for meters, but also a plurality of EEPROMs 11, 21, 31, and 41 mounted on the vehicle. As a result, by simply rewriting a value d1 stored in the EEPROM 11 of the ECU 10 for meters, it becomes difficult to manipulate the driven distance integrated value (x) to a small value. Additionally, the person carrying out manipulation is disabled to find out easily on which EEPROMs mounted to the vehicle the dispersed driven distance integrated values d2 to d4 are stored. Further, even if it is known on which EEPROM the driven distance integrated values are dispersed and stored, it is difficult to restore the dispersed values to an arbitrary driven distance integrated values, so that fraudulent manipulation is prevented from being easily performed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle mileage integrated value storage system for storing a mileage integrated value of a vehicle.
[0002]
2. Description of the Related Art
Conventionally, the mileage integrated value is written, updated, and stored in nonvolatile storage means such as an EEPROM provided in a meter unit for displaying the mileage integrated value as the total mileage of the vehicle.
[0003]
By the way, the running distance integrated value stored in the EEPROM is important for grasping how the vehicle has been used. For example, in the used car market, cars with a short total mileage are popular, and such cars are often traded at a high price. For this reason, in order to increase the price when buying and selling a used car, a situation has arisen in which the integrated mileage stored in the EEPROM is rewritten to a small value and tampered with.
[0004]
However, in the related art, since the integrated value of the traveling distance is simply stored in one EEPROM, the illegal tampering can be easily performed.
[0005]
In view of the above, an object of the present invention is to make it difficult for a stored mileage integrated value to be tampered with in a vehicle mileage integrated value storage system that stores the mileage integrated value of a vehicle.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the integrated value of the traveling distance of the vehicle is stored in a distributed manner in a plurality of nonvolatile storage means (11, 21, 31, 41) mounted on the vehicle. It is characterized by:
[0007]
As a result, it is difficult to falsify the mileage integrated value to a small value by simply rewriting the storage content of one storage unit. Also, it is not easy for a falsifier to know which storage means the mileage integrated value is stored in the storage means mounted on the vehicle. Even if it is known, it is difficult to restore the scattered value to the original mileage integrated value, so that the illegal tampering can be made difficult.
[0008]
In addition, as a specific example of such distributed storage, as in the second aspect of the present invention, it is possible to dispersely store the data for each digit of the mileage integrated value.
[0009]
By the way, in the invention described in claim 1 or 2, all of the plurality of non-volatile storage means (11, 21, 31, 41) are storage means provided in a meter unit for displaying the mileage integrated value. In such a case, it is not possible to prevent a tampering method by replacing the meter unit with a meter unit storing a small value of the mileage integrated value for each meter unit.
[0010]
According to the third aspect of the present invention, one of the plurality of nonvolatile storage units (11, 21, 31, 41) is provided with a meter unit (10U) for displaying the mileage integrated value. And the other storage means of the plurality of nonvolatile storage means (11, 21, 31, 41) is replaced with a nonvolatile storage means provided outside the meter unit (10U). (21, 31, 41).
[0011]
As a result, even if the meter unit (10U) is replaced as described above, it is difficult to restore a value close to the original mileage integrated value by the dispersed value. Tampering can be made difficult.
[0012]
According to the invention described in claim 4, each unused area (21b, 31b) of the plurality of nonvolatile storage means (21, 31) is recognized as one virtual nonvolatile storage means (60), Since the integrated mileage is stored in the nonvolatile storage means (60), the nonvolatile storage means (21, 31) can be effectively used.
[0013]
It should be noted that reference numerals in parentheses of the above-described units are examples showing the correspondence with specific units described in the embodiments described later.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
(1st Embodiment)
FIG. 1 is a system configuration diagram showing a vehicle mileage integrated value storage system of the present embodiment.
[0016]
Reference numeral 10 denotes an electronic control unit for a meter (hereinafter, referred to as an ECU), which controls the operation of a meter mounted on a vehicle. The meter ECU 10 is connected to other ECUs 20, 30, and 40 mounted on the vehicle via a communication line, and can communicate with each other via an in-vehicle LAN or the like.
[0017]
Incidentally, the ECU 20 is a navigation ECU that controls the operation of the navigation device mounted on the vehicle, the ECU 30 is an air conditioner ECU that controls the operation of the vehicle air conditioner, and the ECU 40 controls the operation of the engine. This is an engine ECU. Each of the ECUs 10 to 40 includes EEPROMs 11, 21, 31, and 41 as rewritable nonvolatile storage means.
[0018]
Here, the meter ECU 10 is provided in a meter unit 10U installed on an instrument panel located in front of the passenger car, and FIG. 2 is a front view of the meter unit 10U. The meter unit 10U of this embodiment is configured as a combination meter, and includes a speedometer S, a tachometer T, a shift indicator I, and an electronic mileage integrator D.
[0019]
The speedometer S indicates the vehicle speed of the passenger car by a scale plate 12 and a pointer 13. The scale plate 12 is attached to an opening 15a of a bottom wall 15 of an annular dial plate 14 from the back side. . Further, the mileage integrator D includes a liquid crystal panel 16 as a display device, and the liquid crystal panel 16 is provided alongside an opening 12a of the scale plate 12 from the back side. The liquid crystal panel 16 digitally displays the integrated value of the traveling distance of the passenger car as the total traveling distance. Incidentally, the liquid crystal panel 16 of the present embodiment can display values from 0 km to 999,999 km.
[0020]
Further, as shown in FIG. 1, the travel distance integrator D includes a microcomputer 17, a drive circuit 18, the above-described EEPROM 11, and the like. The microcomputer 17 includes a CPU, a ROM, and the like, and starts execution based on a computer program stored in the ROM in advance under operation of an ignition switch IG of the passenger car.
[0021]
Then, the microcomputer 17 executes a calculation process for calculating the integrated value of the traveling distance of the passenger car based on the detection output of the vehicle speed sensor Sv. The microcomputer 17 is supplied with power directly from a battery Ba mounted on the passenger car, and is maintained in an operating state. The vehicle speed sensor Sv uses a vehicle speed sensor of the speedometer S, and the vehicle speed sensor Sv detects the vehicle speed of the passenger car.
[0022]
Further, the microcomputer 17 causes the EEPROMs 11, 21, 31, and 41 of the ECUs 10 to 40 to dispersely store the calculated running distance integrated values.
[0023]
Specifically, assuming that the mileage integrated value is x and the values stored in the EEPROMs 11, 21, 31, and 41 are d1, d2, d3, and d4, respectively, d1 = f1 (x) and d2 = f2 (x). , D3 = f3 (x) and d4 = f4 (x), the microcomputer 17 calculates the variances d1 to d4. Incidentally, the above f1 to f4 are functions of x, are functions of different mathematical expressions, and are functions stored in the ROM of the microcomputer 17 in advance.
[0024]
Then, the microcomputer 17 stores the dispersion values d1 in the EEPROM 11, and transmits the dispersion values d2 to d4 to the navigation ECU 20, the air conditioner ECU 30, and the engine ECU 40, respectively. The ECUs 20 to 40 store the variance values d2 to d4 in the EEPROMs 21 to 41, respectively.
[0025]
When displaying the mileage integrated value on the liquid crystal panel 16 of the meter unit 10U, the microcomputer 17 restores the original mileage integrated value x from each of the variance values d1 to d4, and obtains the restored value. A signal is output to the drive circuit 18 based on x. As a result, the running distance integrated value x is displayed on the liquid crystal panel 16.
[0026]
In restoring the integrated value x, a function f satisfying x = f (d1, d2, d3, d4) is stored in advance in the ROM of the microcomputer 17, and the integrated value x is calculated based on the function f. And restore it.
[0027]
According to the present embodiment configured as described above, the integrated value of the mileage of the vehicle is dispersed and stored not only in the EEPROM 11 of the meter ECU 10 but also in the plurality of EEPROMs 11, 21, 31, and 41 mounted on the vehicle. Therefore, it is difficult to falsify the mileage integrated value x to a small value simply by rewriting the value d1 stored in the EEPROM 11 of the meter ECU 10.
[0028]
Further, it is not easy for a falsified person to know which of the EEPROMs mounted on the vehicle has the dispersed mileage integrated values d2 to d4 stored therein. It is difficult to restore the dispersed value to an arbitrary integrated value of the traveling distance even if it is known that the illegal tampering has been performed.
[0029]
By the way, as one of the methods of illegal tampering, there is an act of replacing every meter unit 10U with a meter unit 10U in which a small mileage integrated value is stored. On the other hand, the EEPROMs 21, 31, and 41 that store the distributed values d2 to d4 in the present embodiment are storage means provided outside the meter unit 10U, and therefore, temporarily store the meter unit 10U as described above. Even if it is replaced, it is difficult to restore the dispersed values d2 to d4 to the original displayable travel distance integrated value x, so that it is difficult to falsify the signature.
[0030]
(2nd Embodiment)
FIG. 3 is a diagram showing the concept of the vehicle mileage integrated value storage system according to the present embodiment. The meter ECU 10 includes a navigation ECU 20, an air conditioner ECU 30, and a non-volatile memory 21 included in other ECUs connected via an in-vehicle LAN. , 31 are managed.
[0031]
That is, in general, the maps of the nonvolatile memories 21 and 31 are divided into used areas 21a and 31a used for storing data and unused areas 21b and 31b not used for storing data. The meter ECU 10 receives information indicating which part of the maps of the nonvolatile memories 21 and 31 is the unused area 21b or 31b.
[0032]
Then, the meter ECU 10 constructs one unused nonvolatile area 21b, 31b in one virtual nonvolatile memory 60 based on the information, and makes the virtual nonvolatile memory 60 recognized by the vehicle mileage integrated value storage system. Then, the travel distance integrated value calculated by the microcomputer 17 is stored in the virtual nonvolatile memory 60. Therefore, as a result, the mileage integrated value is distributed and stored in the unused areas 21b and 31b of the plurality of nonvolatile memories 21 and 31.
[0033]
As described above, according to the present embodiment, the traveling distance integrated value is dispersedly stored in the plurality of non-volatile memories 21 and 31 mounted on the vehicle, so that the same effect as in the first embodiment can be exerted. Further, according to the present embodiment, since the mileage integrated values are stored in the unused areas 21b and 31b of the plurality of nonvolatile memories 21 and 31, respectively, the nonvolatile memories 21 and 31 can be effectively used. .
[0034]
(Other embodiments)
In the first embodiment, three EEPROMs 21, 31, and 41 are employed as other storage means of the EEPROM 11 of the meter ECU 10, and the mileage integrated value x is distributed and stored in the four EEPROMs 11 to 41. In implementing the present invention, the number of storage means for distributed storage is not limited to four, but may be any number as long as it is two or more.
[0035]
Then, it is preferable that the data is dispersedly stored in the same number of storage means as the number of digits that can be displayed by the display means 16, and that the accumulated distance is stored separately for each digit. That is, when six-digit values from 0 km to 999,999 km can be displayed as in the display means 16 shown in FIG. 2, the values of each digit are dispersedly stored in six EEPROMs. It is suitable.
[0036]
Further, in the embodiment of the present invention, dispersal storage in the storage means 21, 31, 41 outside the meter unit 10U is abolished, and a plurality of non-volatile storage means provided in the meter unit 10U are stored in the nonvolatile storage means. May be stored in a distributed manner.
[0037]
In the embodiment of the present invention, the storage of the mileage integrated value in the storage unit 11 of the meter ECU 10 is abolished, and the storage unit outside the meter ECU 10 is included in the storage units 21, 31, and 41 mounted on the vehicle. The running distance integrated values may be stored in a distributed manner in 21, 31, and 41.
[0038]
In the second embodiment, the meter ECU 10 manages the virtual nonvolatile memory 60. However, the virtual nonvolatile memory 60 may be managed by a vehicle-mounted ECU different from the meter ECU 10.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a vehicle mileage integrated value storage system according to a first embodiment of the present invention.
FIG. 2 is a front view of the meter unit shown in FIG.
FIG. 3 is a diagram showing a concept of a vehicle mileage integrated value storage system according to a second embodiment of the present invention.
[Explanation of symbols]
10U ... meter unit,
11 EEPROM of meter ECU (non-volatile storage means),
21: EEPROM (non-volatile storage means) of the navigation ECU,
31: EEPROM (non-volatile storage means) of the air conditioner ECU,
41: EEPROM (non-volatile storage means) of the engine ECU.

Claims (4)

A vehicle mileage integrated value storage system, wherein a vehicle mileage integrated value is distributed and stored in a plurality of nonvolatile storage means (11, 21, 31, 41) mounted on the vehicle. 2. The vehicle mileage integrated value storage system according to claim 1, wherein the mileage integrated value is dispersedly stored for each digit. One of the plurality of nonvolatile storage means (11, 21, 31, 41) is a nonvolatile storage means (11) provided in a meter unit (10U) for displaying the mileage integrated value,
The other nonvolatile storage unit of the plurality of nonvolatile storage units (11, 21, 31, 41) is a nonvolatile storage unit (21, 31, 41) provided outside the meter unit (10U). The integrated vehicle mileage storage system according to claim 1 or 2, wherein: Unused areas (21b, 31b) of the plurality of nonvolatile storage means (21, 31) are recognized as one virtual nonvolatile storage means (60),
The vehicle mileage integrated value storage system according to any one of claims 1 to 3, wherein the mileage integrated value is stored in the virtual nonvolatile storage means (60).

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