JP3698425B2 - Vehicle electronics - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicular electronic device mounted on a vehicle, and more particularly to a technology that enables accurate time information to be shared among devices mounted on a plurality of vehicles.
[0002]
[Prior art]
In general, a device that holds time information creates time information by using oscillation of an oscillator in the device.
[0003]
[Problems to be solved by the invention]
As described above, since a device having conventional time information creates time information using an oscillator, a difference occurs in the created time information depending on the accuracy of the oscillator. When there are multiple vehicles equipped with such devices, the time information displayed on each vehicle will be shifted, and it will not be possible to record accurate information in operation management records where time information is important. There is concern that management may be hindered.
[0004]
In JP-A-8-122467, JP-A-10-307193, etc., a plurality of devices are connected by a control line, and one of those devices transmits its own time information to the control line, There has been proposed a method in which another device that detects time information to be transmitted adjusts time information among a plurality of devices by rewriting its own time information. However, in the case of this prior art, it is necessary to always interconnect a plurality of devices with a control line, that is, a cable such as a cable, rather than wirelessly, so that time information is consistent between a plurality of vehicles in driving state. It is difficult in some cases.
[0005]
Japanese Patent Laid-Open No. 2001-199370 proposes a method of receiving a radio wave including standard time information and correcting its own time information with reference to the information. If it is not good, there is a problem that it is corrected according to inaccurate time information.
[0006]
On the other hand, in JP-A-8-249594, for the purpose of operation management, a GPS receiver is connected to the operation management meter of each vehicle, and the time of the operation management meter is corrected based on time data obtained from GPS satellites. Although a system has been proposed, there is a problem that an expensive GPS receiver is required for all vehicles.
[0007]
In particular, when an accident involving multiple vehicles occurs in a device such as a drive recorder that records the situation at the time of the traffic accident, the time information of one of the vehicles is corrected to the inaccurate information. If this is done, there is a problem that it becomes difficult to determine which of the time information recorded in each device should be trusted.
[0008]
In addition, if the output of time information is tampered with, the reliability of the recorded information itself is lost.
[0009]
The present invention has been made to solve the above problems, and even when each vehicle is in operation, accurate time information can be shared between devices mounted on each of the plurality of vehicles. And it aims at providing the electronic device for vehicles which can be implemented cheaply.
[0010]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a vehicular electronic device comprising: a vehicular electronic device having time information; an internal time calculation means for internally calculating the time and outputting time data; and data communication with other vehicles wirelessly. Communication means for performing communication, network construction means for constructing a network with other vehicles using the communication means, and determining the latest time information as a reference time among the plurality of time information possessed by the vehicles constructing the network A reference time determination unit that receives the reference time information determined by the reference time determination unit using the communication unit, and a delay correction unit that corrects a delay that occurs when the reception unit receives the reference time information. And internal time correction means for correcting the time information of the internal time calculation means using the reference time information corrected by the delay correction means, and further Including a condition that the communication state by the communication means is normal as a condition that enables correction of the time monitored by the condition monitoring means. It is characterized by that.
[0011]
According to a second aspect of the present invention, there is provided a vehicular electronic device according to the first aspect of the present invention, wherein the vehicle is in an operating state as a condition that enables correction of the time monitored by the condition monitoring means. It is characterized by including.
[0012]
According to a third aspect of the present invention, there is provided a vehicular electronic device according to the first or second aspect of the present invention, wherein in the configuration of the first or second aspect of the invention , manual time correction is started as a condition that enables correction of the time monitored by the condition monitoring means. It is characterized by including requirements in conditions.
[0013]
According to a fourth aspect of the present invention, there is provided a vehicle electronic device according to any one of the first to third aspects, wherein the time is internally calculated and time data is output. A change input means for making an input related to setting of an initial value and a change of time information to the internal time calculation means, and an identification means for identifying a specific device or person by an identification code. The time information is not changed by the change input means unless it is a device or a person identified by.
[0014]
According to a fifth aspect of the present invention, there is provided a vehicle electronic device according to any one of the first to third aspects, wherein the time is internally calculated and time data is output. And a secret numerical value that is secret to a third party, time data output by the internal time calculating means, and a secret numerical value or secret calculation processing means that calculates the secret numerical value according to a specific calculation procedure, By outputting the calculation result by the calculation processing means as signature information together with the time data, the time data is prevented from being falsified.
[0015]
A vehicle electronic device according to a sixth aspect of the invention records information indicating that data communication has been performed with a device outside the vehicle in the configuration of the invention according to any one of the first to third aspects. Means are provided.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Figure 1 is a block diagram of a time adjustment method in more vehicle according to a first embodiment of the present invention.
[0017]
In the figure, reference numerals 501, 512, and 513 denote vehicles, and reference numeral 502 denotes time information serving as a reference from time information output by an internal time calculating means 506 described later and time information received by a time information receiving means 509 described later. Reference time determination means for determining. Reference numeral 503 denotes communication means, which can communicate with other vehicles 512 and 513 via the antenna 504 by radio. Reference numeral 505 denotes network construction means for determining whether or not the communication means 503 can normally communicate with other vehicles 512 and 513, making a communication request to the communication means 503, and constructing a network with other vehicles. 506 is an internal time calculation means, and an IC that outputs time information such as RTC (Real Time Clock) is known. Reference numeral 507 denotes an internal time correction unit which gives a correction input so as to correct the time of the internal time calculation unit 506 to a target time. A condition monitoring unit 508 determines whether or not to start correction of the internal time. Reference numeral 509 denotes time information receiving means, which is an apparatus for receiving time information from other vehicles 512 and 513 using the communication means 503. Reference numeral 510 denotes a delay correction unit, which calculates a delay time required when the time information reception unit 509 receives time information from another vehicle 512 or 513, and inputs a correction input of the internal time correction unit 507 as more accurate time information. It is a device to control. Reference numeral 511 denotes time correction completion monitoring means, which is an apparatus for monitoring the completion of the above series of time correction processing.
[0018]
Figure 2 is a flowchart showing the operation of the arrangement of Figure 1. In FIG. 2 , when the process is started in step S601, first, the condition monitoring unit 508 in FIG. 5 determines whether or not wireless communication with other vehicles 512 or 513 is possible using the network construction unit 505 in step S602. Make a decision. If it is not possible to connect to another vehicle here, the process jumps to step S615 to end the process. If it can be connected to another vehicle, the process jumps to step S603 to establish a network connection with the other vehicle.
[0019]
Next, in step S604, the time at which the previous correction processing was performed is transmitted to the other vehicle, and in step S605, the previous correction processing time in the other vehicle is received.
[0020]
In step S606, the reference time determination unit 502 compares both times. If the previous correction processing time in the own vehicle is newer, the reference time determination unit 502 determines its time information as the reference time in step S613. In step S614, the determined reference time is transmitted to the other vehicle using the communication unit 503, and the process jumps to step S612.
[0021]
On the other hand, in step S606, if the previous correction processing time in the other vehicle is newer than the previous correction processing time in the own vehicle, the time information of the other vehicle is determined as the reference time in step S607, and in step S608. The time information receiving means 509 is used to receive the reference time information transmitted by other vehicles.
[0022]
The reference time information received in step S608 is corrected by the delay correction unit 510 in step S609 and passed to the internal time correction unit 507.
[0023]
In step S610, the internal time correction unit 507 corrects the internal time of the internal time calculation unit 506 based on the received reference time information, and notifies the time correction completion monitoring unit 511 of the completion of correction.
[0024]
In step S611, if the time correction completion monitoring unit 511 detects correction completion, the process jumps to step S612. If the correction is not normally completed due to the influence of noise or the like, the process returns to step S608 and the time correction process is performed again.
[0025]
In step S612, time information when the correction process is completed is recorded and used as an index for the next correction start condition.
[0026]
In step S613, a series of processing ends.
[0027]
With the above processing, since the latest time information is always adopted among a plurality of devices that are physically close to each other, the time lag between devices can be reduced, and in applications such as drive recorders that store traffic accident status information, Even if the clock of one of the vehicles related to the accident is broken, it can be adjusted to the time information of the vehicle with accurate time information, and it is determined which time information should be trusted Can be easily performed.
[0028]
Embodiment 2 FIG.
FIG. 3 is a configuration diagram of a time adjustment method in a plurality of vehicles according to Embodiment 2 of the present invention.
[0029]
In the figure, reference numeral 901 denotes an apparatus for controlling a series of correction methods for time information explained in the first embodiment, and is called time information control means for explanation. Reference numeral 902 denotes time information calculation means, and an IC that outputs time information such as RTC (Real Time Clock) is known. Reference numeral 903 denotes an input unit that gives input to the time information calculation unit 902 to correct the time, or an authentication unit that authenticates whether or not a person is permitted to do so.
[0030]
The authentication unit 903 requests the person who intends to correct the time of the time information calculation unit 902 or a person to input the authentication code as input data, and sets the permitted authentication code held by the authentication unit 903. If there is no match, correction of time information is not permitted.
[0031]
With the above processing, the time information is not changed illegally, and the reliability of the output time information can be improved.
[0032]
Here, for example, in a use such as a drive recorder for storing information on the traffic accident situation, the same effect can be expected even if the time information calculation means 902 is replaced with the time information recorded by the drive recorder.
[0033]
Embodiment 3 FIG.
FIG. 4 is a configuration diagram of a time adjustment method in a plurality of vehicles according to Embodiment 3 of the present invention.
[0034]
In the figure, reference numeral 911 denotes the time information output apparatus described in the first to fourth embodiments, and is referred to as time information control means for the sake of explanation. 912 is time information calculation means, and an IC that outputs time information such as RTC (Real Time Clock) is known. Numeral 913 is a numerical value that is not disclosed to a third party, and is referred to as a key value for explanation. Reference numeral 914 denotes an arithmetic unit that performs an arithmetic operation using the time information output from the time information arithmetic unit 912 and the key value 913, and generates a signature code that can be generated only from the time information and the key value.
[0035]
With the above processing, even if a third party falsifies the time information output by the time information calculation means 912, the signature code generated at that time cannot be forged because the key value 913 is not known. By comparing the two with a fair organization that knows the key value, it is possible to discover whether or not tampering has occurred, and it is possible to improve the reliability of data for time information that is determined to have not been tampered with. .
[0036]
【The invention's effect】
As described above, according to the present invention, even when there are a plurality of electronic devices such as vehicles that are physically separated from each other, the deviation of time information displayed in each can be reduced, and the time management information becomes important. In such cases, accurate information can be recorded, and reliability can be improved.
[0037]
Further, the monitoring of the communication state and the radio wave state and the condition determination means for starting correction do not cause correction according to inaccurate time information, and reliability can be improved.
[0038]
On the other hand, it is possible to obtain accurate time information at low cost without mounting an expensive time correction device such as a GPS receiver on the vehicle .
[0039]
Also, the output time information can prevented from being illegally rewritten, it is possible to improve the reliability of the time information.
[0040]
In addition, by recording information indicating that data communication has been performed with a device outside the vehicle, it is possible to determine whether or not the time information has been properly obtained, and reliability can be improved.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an overall configuration of a vehicle electronic device in a plurality of vehicles according to Embodiment 1 of the invention.
FIG. 2 is a flowchart showing the operation of the first embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of time information control means of a vehicle electronic device in a plurality of vehicles according to Embodiment 2 of the present invention.
FIG. 4 is a block diagram showing a configuration of time information control means of a vehicle electronic device in a plurality of vehicles according to Embodiment 3 of the present invention.
[Explanation of symbols]
501, 512, 513 vehicle, 502 reference time determination means, 503 communication means,
504 antenna, 505 network construction means, 506 internal time calculation means,
507 internal time correction means, 508 condition monitoring means, 509 time information receiving means,
510 delay correction means, 511 time correction completion monitoring means,
901, 911 time information control means, 902, 912 time information calculation means,
903 Authentication means, 913 key value, 914 arithmetic processing.

Claims (6)

In an electronic device for vehicles having time information, internal time calculation means for internally calculating the time and outputting time data, communication means for wirelessly communicating data with other vehicles, and other communication using the communication means Network construction means for constructing a network with the vehicle, reference time determination means for determining the latest time information as a reference time from among the plurality of time information possessed by the vehicles constructing the network, and the reference time determination means Receiving means for receiving the determined reference time information using the communication means, delay correcting means for correcting a delay generated when the receiving means receives the reference time information, and reference time information corrected by the delay correcting means. And an internal time correction unit that corrects time information of the internal time calculation unit, and further monitors conditions for enabling the time correction process. And a matter monitoring means, said condition as a condition for correction becomes possible time to be monitored by the monitoring means, the vehicular electronic device, wherein the inclusion of conditions that the communication state by the communication means is normal. 2. The vehicle electronic device according to claim 1, wherein the condition that the time monitored by the condition monitoring unit can be corrected includes that the vehicle is in an operating state. 3. The vehicular electronic device according to claim 1, wherein a manual time correction start request is included in the condition as a condition that enables correction of the time monitored by the condition monitoring means. Internal time calculation means for internally calculating the time and outputting time data, change input means for making an input regarding the setting of initial values and change of time information to the internal time calculation means, and a specific device or person An identification means for identifying a certain thing by an identification code, and the time information is not changed by the change input means unless it is a device or a person identified by the identification means. Item 4. The vehicle electronic device according to any one of Item 3. Internal time calculation means for calculating the time internally and outputting the time data, a secret numerical value to a third party, the time data output by the internal time calculation means and the secret numerical value according to a specific calculation procedure A third party that operates is provided with a secret or public calculation processing means, and the calculation result by the calculation processing means is output as signature information together with the time data, thereby preventing the time data from being falsified. The vehicular electronic device according to any one of claims 1 to 3. The vehicle electronic device according to any one of claims 1 to 3, further comprising means for recording information indicating that data communication has been performed with a device outside the vehicle.

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