JP2015121463A - Operation state recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for easily identifying whether or not the cause of the shortening of an inter-vehicle distance lies in the interruption of another vehicle.SOLUTION: Warning determination means (S120) determines whether or not an inter-vehicle distance between an own vehicle and a preceding vehicle is less than a warning threshold. Recording means (S150 to S168) records the operation state of the own vehicle including the inter-vehicle distance when it is determined that the inter-vehicle distance is less than the warning threshold. Interruption determination means (S140) determines whether or not the secular change of the inter-vehicle distance is caused by the interruption of another vehicle on the basis of a first inter-vehicle distance determined to be less than the warning threshold and a second inter-vehicle distance being the inter-vehicle distance acquired before the first inter-vehicle distance. Recording means identifiably records the operation state including the first inter-vehicle distance whose secular change is determined to be caused by the interruption and the operation state including the first inter-vehicle distance whose secular change is determined to be not caused by the interruption.

Description

  The present invention relates to an operation status recording apparatus used in a vehicle.

  For example, in the transportation industry, a digital tachograph is widely introduced as an operation status recording device that records an operation status such as a traveling speed or traveling time of a vehicle. The operation manager who manages the operation of the vehicle identifies the dangerous driving such as sudden acceleration / deceleration and sudden steering based on the recorded driving situation, and based on the identified dangerous driving, the driver Provides safe driving guidance to Examples of driving with danger include meandering driving due to snoozing driving, abnormal approach to a preceding vehicle, etc., in addition to sudden acceleration / deceleration and sudden steering. Patent Document 1 discloses a configuration for recording the operation status when the inter-vehicle distance between the host vehicle and the preceding vehicle becomes shorter than a predetermined threshold (when an abnormal approach to the preceding vehicle occurs). Has been.

JP 2009-199328 A

  As a factor that causes the distance between the host vehicle and the preceding vehicle to be shorter than a predetermined threshold (a factor that causes an abnormal approach to the preceding vehicle), driving by the driver of the host vehicle (driving to reduce the inter-vehicle distance) In addition to the above, there is an interruption of another vehicle ahead of the host vehicle. For this reason, there has been a case where proper safe driving guidance cannot be performed unless the cause of the reduction in the inter-vehicle distance is taken into consideration.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a technique for identifying whether or not the cause of the reduction in the inter-vehicle distance is due to an interruption of another vehicle. .

  One aspect of the present invention is an operation status recording apparatus used in a vehicle, and includes an inter-vehicle distance acquisition unit, a warning determination unit, a recording unit, and an interrupt determination unit. The inter-vehicle distance acquisition means acquires the inter-vehicle distance between the host vehicle and the preceding vehicle. The warning determination unit determines whether or not the inter-vehicle distance acquired by the inter-vehicle distance acquisition unit is less than a predetermined warning threshold value. When the warning determination means determines that the inter-vehicle distance is less than the warning threshold, the recording means records the operation status of the host vehicle including the inter-vehicle distance. The interrupt determination means includes a first inter-vehicle distance that is determined to be less than the warning threshold by the warning determination means, and an inter-vehicle distance acquired by the inter-vehicle distance acquisition means before the first inter-vehicle distance. Based on the second inter-vehicle distance, it is determined whether or not the temporal change in the inter-vehicle distance is due to an interruption of another vehicle. The recording means includes an operation situation including the first inter-vehicle distance determined by the interruption determination means as a change over time due to an interruption of the other vehicle, and a change over time is not due to an interruption of the other vehicle. The operation status including the determined first inter-vehicle distance is recorded so as to be identifiable.

According to such a configuration, it is possible to easily identify whether or not the cause of the decrease in the inter-vehicle distance is due to the interruption of another vehicle based on the change over time in the inter-vehicle distance.
In addition, the code | symbol in the parenthesis described in the claim shows the correspondence with the specific means as described in embodiment mentioned later as one aspect, Comprising: The technical scope of this invention is limited is not.

It is a block diagram which shows the structure of the operation condition recording system of 1st Embodiment. It is a flowchart of an inter-vehicle distance recording process. (A) is a figure which shows an example of the time-dependent change of the inter-vehicle distance not caused by the interruption of other vehicles, (b) is a figure which shows an example of the time-dependent change of the inter-vehicle distance caused by interruptions of the other vehicle. It is. (A) is a figure which shows an example of the predicted value of the inter-vehicle distance in the time-dependent change of the inter-vehicle distance which is not caused by the interruption of the other vehicle, and (b) is the time-dependent change of the inter-vehicle distance caused by the interruption of the other vehicle. It is a figure which shows an example of the predicted value of the inter-vehicle distance in a change. It is a flowchart of the inter-vehicle distance recording process of 2nd Embodiment. It is a flowchart of an interrupt determination process.

Embodiments to which the present invention is applied will be described below with reference to the drawings.
[1. First Embodiment]
[1-1. Constitution]
An operation status recording system 1 shown in FIG. 1 is mounted on a vehicle (for example, a truck of a carrier), a digital tachograph 10, a communication device 11, an imaging device 12, an inter-vehicle distance measuring device 13, a GPS receiver 14, and a vehicle speed. A sensor 15 is provided.

  The communication device 11 performs wireless communication with, for example, a communication device provided in a carrier's office. The communication device 11 transmits the position of the own vehicle detected by, for example, a GPS receiver 14 to be described later in order to facilitate the dispatch of a truck or the like at the carrier's office.

  The imaging device 12 is installed at a predetermined position in the room of the host vehicle, for example, on the back side of the room mirror, in order to capture the front of the host vehicle. The imaging device 12 images the front of the host vehicle at a predetermined cycle (for example, every 100 msec), and outputs captured image data to the digital tachograph 10 (control unit 25).

  The inter-vehicle distance measuring device 13 is arranged at a predetermined position in the front portion of the host vehicle, for example, at the center of the front bumper, and detects the distance between the preceding vehicle and the host vehicle (inter-vehicle distance). The inter-vehicle distance measuring device 13 transmits radio waves (for example, millimeter waves) in front of the host vehicle, receives a reflected wave from a target located in front of the host vehicle, and detects the inter-vehicle distance based on the reception result of the reflected wave. The detected inter-vehicle distance is output to the digital tachograph 10 (control unit 25). In addition, since the method of specifying the preceding vehicle and detecting the inter-vehicle distance is a well-known technique, detailed description is omitted.

  The GPS receiver 14 receives a positioning signal from an artificial satellite for GPS (Global Positioning System), detects the position (latitude and longitude) of the host vehicle based on the received positioning signal, and detects the detection result as a digital tachograph 10. Output to (control unit 25).

  The vehicle speed sensor 15 detects the rotational speed of the axle based on the number of pulses per unit time output from a pulse generator attached to the axle of the host vehicle, and determines the speed of the host vehicle based on the detected rotational speed. The calculation result is output to the digital tachograph 10 (control unit 25).

  The digital tachograph 10 includes a G sensor 21, a gyroscope 22, a storage unit 23, a card interface unit 24, a control unit 25, an operation switch unit 26, and an audio output unit 27.

  The G sensor 21 detects the acceleration in the front-rear direction of the host vehicle, and outputs the detection result to the control unit 25. The gyroscope 22 detects the magnitude of the rotational motion applied to the host vehicle, and outputs the detection result to the control unit 25. The storage unit 23 includes a rewritable storage device such as a flash ROM, for example.

  The card interface unit 24 reads / writes information from / to the memory card 40 inserted in a card slot (not shown). The memory card 40 is a portable external storage device, and the card interface unit 24 outputs a signal indicating that the memory card 40 is inserted to the control unit 25 when the memory card 40 is inserted in the slot. To do.

  The operation switch unit 26 is provided at a position where the driver can easily operate the main body of the digital tachograph 10, and includes a plurality of switches. For example, the operation switch unit 26 includes a memory card extraction switch for extracting the memory card 40 inserted in the card interface unit 24. In addition, the operation switch unit 26 is a switch for recording the work content when the driver leaves the host vehicle in the storage unit 23, for example, carrying out a task of loading a load on the host vehicle (during loading). A switch indicating that the work is being carried out (unloading), a switch indicating that the user is taking a break, and the like. When an operation (for example, an operation of pressing a switch) is performed on the operation switch unit 26 by a driver, a signal indicating that the operation has been performed is output to the control unit 25.

The voice output unit 27 outputs various guidance (notification) voices input from the control unit 25.
The control unit 25 is configured with a known microcomputer centering on the CPU 51, ROM 52, and RAM 53. The control unit 25 (specifically, the CPU 51) executes various processes based on the program stored in the ROM 52.

Here, a process executed by the control unit 25 in order to realize the function of the general digital tachograph 10 will be described.
For example, while the memory card 40 is inserted into the card interface unit 24, the control unit 25 detects the speed of the host vehicle acquired from the vehicle speed sensor 15, the longitudinal acceleration of the host vehicle acquired from the G sensor 21, and the gyroscope 22. The process of recording in the storage unit 23 the magnitude of the rotational motion applied to the host vehicle obtained from the above. In addition, for example, when the overspeed of the host vehicle is detected based on the acquired speed of the host vehicle, the control unit 25 performs a process of notifying the driver by the voice output unit 27 that the overspeed is detected. Furthermore, the control unit 25 detects, for example, sudden acceleration and sudden deceleration based on the acquired longitudinal acceleration of the host vehicle, and a sudden handle by the driver based on the acquired magnitude of the rotational motion. When the operation is detected, a process of notifying the driver by the voice output unit 27 that the sudden acceleration / deceleration and the sudden steering operation are detected is performed.

  Further, the control unit 25 performs a process of recording the work content when the driver leaves the host vehicle in the storage unit 23 based on the input from the operation switch unit 26. Furthermore, the control unit 25 writes the data stored in the storage unit 23 to the memory card 40 based on the input from the operation switch unit 26 (memory card removal switch), and then the card interface unit 24. Processing to enable extraction of the memory card 40 from the (card slot) is performed. Since these processes are well-known processes in the digital tachograph 10, a detailed description of each process is omitted.

[1-2. processing]
Next, among the processes executed by the CPU 51, the inter-vehicle distance recording process executed for recording the operation status of the own vehicle including the inter-vehicle distance between the own vehicle and the preceding vehicle will be described with reference to the flowchart of FIG. explain. 2 is executed at a predetermined cycle while the memory card 40 is inserted into the card interface unit 24.

_First , in S (step) 100, the value stored in the RAM 53 as the inter-vehicle distance d _n-1 is updated to the value stored in the RAM 53 as the inter-vehicle distance d _n (d _n-1 ← d _n ). Here, inter-vehicle distance d _n-1 denotes the detected inter-vehicle distance to the preceding cycle, the inter-vehicle distance d _n, showing the headway distance detected by the current cycle. At the start of the inter-vehicle distance recording process (before processing in S100 is executed), as the vehicle distance d _n-1 and the inter-vehicle distance d _n, the value relative to the preceding cycle is stored in the RAM 53, In S100, the value of the inter-vehicle distance dn _-1 is updated so as to be shifted by one cycle.

Next, in S110, newly obtains the inter-vehicle distance detected at present by the inter-vehicle distance measuring apparatus 13, the value stored in the RAM53 as the vehicle distance d _n (value relative to the preceding cycle), new Update to the value of the acquired inter-vehicle distance (d _n ← newly acquired inter-vehicle distance).

In subsequent S120, the inter-vehicle distance d _n is equal to or less than a predetermined alarm threshold value Dth. Particularly in this embodiment, it is in the inter-vehicle distance d _n-1 is warning threshold Dth or more, and, when the inter-vehicle distance d _n is less than the warning threshold Dth, YES is determined in S120. That is, it is determined whether or not the inter-vehicle distance has changed shortly across the warning threshold value Dth. If a negative determination is made in S120, the inter-vehicle distance recording process is terminated, and if an affirmative determination is made, the process proceeds to S130. Warning threshold Dth is the inter-vehicle distance d whether _n is the state is too short or criteria become threshold, i.e., whether the measure is a state where the vehicle is too close to the preceding vehicle Is the value.

In S130, the information stored in the RAM53 as the operation situation Dd _n, and updates the information indicating the operation status of the vehicle at the current time, including an inter-vehicle distance d _n. Here, operation status Dd _n indicates the operation status of the vehicle detected in the current cycle. Before the process of S130 is executed, the operation status Dd _n, running condition of the vehicle detected in the preceding cycle is stored in the RAM 53, it is updated to operation status of the current cycle in S130. The operation status of the vehicle, for example, inter-vehicle distance d _n, the time that the inter-vehicle distance d _n is found, the position of the vehicle detected by the GPS receiver 14 at the time when the vehicle distance d _n is found, the inter-vehicle distance speed of the vehicle in which d _n is detected by the vehicle speed sensor 15 at the time of the detected image data representing an image captured by the imaging device 12 for inter-vehicle distance d _n before and after with reference to the time they are detected 10 seconds, etc. Say.

Next, in S140, based on the vehicle distance d _n-1 and the inter-vehicle distance d _n, it determines whether the change over time in the inter-vehicle distance is due to the interruption of the other vehicle. Specifically, in this step, the difference between the inter-vehicle distance d _n-1 and the inter-vehicle distance d _n is the case where the first interrupt threshold D above, those changes over time is due to the interruption of the other vehicle It is determined that Here, if it is determined that the change over time in the inter-vehicle distance is due to an interruption of another vehicle, the process proceeds to S160, and if it is determined that the change in the inter-vehicle distance over time is not due to an interruption of the other vehicle. The process proceeds to S150.

FIG. 3A is a diagram illustrating an example of a change over time in the inter-vehicle distance that is not caused by an interruption of another vehicle. An example of the case where the inter-vehicle distance is less than (or shortens) the warning threshold Dth value is a case where the driver of the host vehicle performs a driving operation that neglects the forward gaze due to drowsy driving or the like. In this case, the inter-vehicle distance d _n with respect to inter-vehicle distance d _n-1, for example, as shown in FIG. 3 (a), changes to become gradually shorter. The difference between the vehicle-to-vehicle distance d _n-1 and vehicle-to-vehicle distance d _n at this time is that the difference Ds.

Moreover, as a case where the inter-vehicle distance is less than (shortens) the warning threshold value Dth, for example, there is a case where an interruption of another vehicle is performed. In this case, the inter-vehicle distance d _n with respect to inter-vehicle distance d _n-1, for example, as shown in FIG. 3 (b), changes so drastically shorter than the case of FIG. 3 (a). The difference between the vehicle-to-vehicle distance d _n-1 and vehicle-to-vehicle distance d _n at this time is called a difference Dh.

That is, as a general tendency, the difference Dh when the other vehicle is interrupted is larger than the difference Ds when the other vehicle is interrupted, for example, when a driving operation that neglects gaze forward is performed. Become. Accordingly, by providing a certain threshold (first interrupt threshold D), based on the difference between the inter-vehicle distance d _n-1 and the inter-vehicle distance d _n, temporal changes in the distance between the vehicles of the other vehicle It is possible to determine whether or not it is due to an interrupt. Particularly in this embodiment, a warning that the vehicle-to-vehicle distance d _n-1 obtained immediately before below the threshold Dth, on the basis of the difference between the inter-vehicle distance d _n obtained immediately after below the warning threshold Dth, It is determined whether or not the change over time in the inter-vehicle distance is due to an interruption of another vehicle.

Meanwhile, the storage unit 23, the inter-vehicle distance falls below the warning threshold Dth, the operation status Dd _n described above is recorded (saved), service administrator after the operation is to be able to verify. When the situation where the inter-vehicle distance falls below the warning threshold value Dth occurs a plurality of times as the host vehicle is driven, the operation status in each situation is recorded in the storage unit 23.

  However, in the present embodiment, there is an upper limit on the number of operation situations stored in the storage unit 23. After the upper limit number (3 in the present embodiment) of the operation status is stored in the storage unit 23, a new operation status to be recorded in the storage unit 23 occurs (a situation where the inter-vehicle distance is below the warning threshold value Dth). When it occurs, the storage information stored in the storage unit 23 is updated so that the shorter the inter-vehicle distance included in the operation status is, the higher the priority is stored. That is, the longest inter-vehicle distance included in the operation status is excluded from the stored information. Particularly in the present embodiment, among the operation situations when the inter-vehicle distance falls below the warning threshold value Dth, the operation situation in which it is determined that the temporal change in the inter-vehicle distance is not due to the interruption of another vehicle, and the inter-vehicle distance over time. The operation status determined to be due to the interruption of the other vehicle is stored in the storage unit 23 in an identifiable manner.

  Here, three operations are performed for the operation status when it is determined that the temporal change in the inter-vehicle distance is not due to an interruption of another vehicle (non-interrupt) among the operation status when the inter-vehicle distance falls below the warning threshold Dth. It is assumed that the situations DS1, DS2, and DS3 are stored in the storage unit 23, and the inter-vehicle distances included in the respective operation situations DS1, DS2, and DS3 are S1, S2, and S3. Further, it is assumed that the inter-vehicle distances S1, S2, and S3 have a relationship of S1 ≦ S2 ≦ S3. In addition, although the state where the number of the operation statuses memorize | stored in the memory | storage part 23 is less than an upper limit may also arise, in this case, empty data should just be considered as an operation status with a sufficiently large distance between vehicles.

For example, if the temporal change of other vehicles interrupt operation status Dd _n determined not due to the inter-vehicle distance is newly generated, if the inter-vehicle distance d _n included in the operation status Dd _n is at S1 or less, Update the information stored as the operation status DS3 to the information stored as the operation status DS2 (DS3 ← DS2), and update the information stored as the operation status DS2 to the information stored as the operation status DS1. (DS2 ← DS1), and updates the information stored the information that is stored as operation status DS1 as operation situation Ddn (DS1 ← _Dd n). That is, information stored as the operation status DS3 (the operation status of the longest inter-vehicle distance) is excluded from the stored information.

Accordingly, the value stored as the inter-vehicle distance S3 is updated to the value stored as the inter-vehicle distance S2 (S3 ← S2), and the value stored as the inter-vehicle distance S2 is stored as the inter-vehicle distance S1. is updated to the value (S2 ← S1), the value stored as the inter-vehicle distance S1 is updated to a value stored as the inter-vehicle distance _{d n (S1 ← d n)} . That is, the value (longest inter-vehicle distance) stored as the inter-vehicle distance S3 is excluded from the stored information. The process of sequentially updating the operation statuses DS1, DS2, and DS3 in this way is a process executed in S150 to S158 in the flowchart shown in FIG.

That is, in S150, the comparison between the inter-vehicle distance S1 and the vehicle distance d _n. Here, the inter-vehicle distance d _n is shifted to S154 if larger than the inter-vehicle distance S1, if the inter-vehicle distance d _n is equal to or less than the inter-vehicle distance S1, proceeds to S151.

In S151, the information stored as the operation status DS3 is updated to the information stored as the operation status DS2 (DS3 ← DS2). Accordingly, the value stored as the inter-vehicle distance S3 is updated to the value stored as the inter-vehicle distance S2 (S3 ← S2). In subsequent S152, the information stored as the operation status DS2 is updated to the information stored as the operation status DS1 (DS2 ← DS1). Accordingly, the value stored as the inter-vehicle distance S2 is updated to the value stored as the inter-vehicle distance S1 (S2 ← S1). Next, in S153, and updates the information stored the information that is stored as operation status DS1 as operation situation _{Dd n (DS1 ← Dd n)} . Accordingly, the value stored as the inter-vehicle distance S1 is updated to a value stored as the inter-vehicle distance _{d n (S1 ← d n)} . That is, stored operation status Dd _n is the most inter-vehicle distance short operation status DS1, Accordingly, information stored as the operation status DS1, DS2 are sequentially rounded down to the operation status DS2, DS3, stored as operation status DS3 The operation status (the operation status with the longest inter-vehicle distance) that has been performed is deleted. Then, the inter-vehicle distance recording process ends.

In S154 the inter-vehicle distance d _n transitions is greater than the inter-vehicle distance S1, and compares the inter-vehicle distance S2 and the vehicle distance d _n. Here, the inter-vehicle distance d _n is shifted to S157 if larger than the inter-vehicle distance S2, if the inter-vehicle distance d _n is equal to or less than the inter-vehicle distance S2, proceeds to S155.

In S155, the same processing as S151 is performed, and the information (including the inter-vehicle distance S3) stored as the operation status DS3 is updated to the information (including the inter-vehicle distance S2) stored as the operation status DS2 (DS3). ← DS2, S3 ← S2). Next, in S156, and updates the information stored the information that is stored as operation status DS2 as operation situation _{Dd n (DS2 ← Dd n)} . Accordingly, the value stored as the inter-vehicle distance S2 is updated to the value stored as the inter-vehicle distance _{d n (S2 ← d n)} . That, is stored as a short operation situation DS2 of the inter-vehicle distance to the second is operation situation Dd _n, Accordingly, information stored as the operation status DS2 is rounded down to the running condition DS3, it has been stored as the operation status DS3 The operation status (the operation status with the longest inter-vehicle distance) is deleted. Then, the inter-vehicle distance recording process ends.

In S157 the inter-vehicle distance d _n transitions is greater than the inter-vehicle distance S2, comparing the vehicle distance S3 and the vehicle distance d _n. Here, the inter-vehicle distance d _n has finished large if the present inter-vehicle distance recording process than the inter-vehicle distance S3, if the inter-vehicle distance d _n is equal to or less than the inter-vehicle distance S3, proceeds to S158.

In S158, and updates the information stored the information that is stored as operation status DS3 as operation situation _{Dd n (DS3 ← Dd n)} . Accordingly, the value stored as the inter-vehicle distance S3 is updated to the value stored as the inter-vehicle distance _{d n (S3 ← d n)} . That is, operation status Dd _n is stored as a short operation situation DS3 of the inter-vehicle distance to the third, along with this, (long operation status of the most inter-vehicle distance) operation condition that has been stored as the operation status DS3 is erased. Then, the inter-vehicle distance recording process ends.

  On the other hand, among the operation situations when the inter-vehicle distance falls below the warning threshold value Dth, the three operation situations DR1 and DR2 are also used for the operation situation in which the change over time in the inter-vehicle distance is determined to be due to the interruption of another vehicle. , DR3 are stored in the storage unit 23, and the inter-vehicle distances R1, R2, R3 included in the respective operation situations DR1, DR2, DR3 have a relationship of R1 ≦ R2 ≦ R3.

In S160, it compares the inter-vehicle distance R1 and the inter-vehicle distance d _n. Here, the process proceeds to the inter-vehicle distance d when _n is greater than the inter-vehicle distance R1 is S164, if the inter-vehicle distance d _n is equal to or less than the inter-vehicle distance R1 proceeds to S161.

In S161, the information stored as the operation status DR3 is updated to the information stored as the operation status DR2 (DR3 ← DR2). Accordingly, the value stored as the inter-vehicle distance R3 is updated to the value stored as the inter-vehicle distance R2 (R3 ← R2). In subsequent S162, the information stored as the operation status DR2 is updated to the information stored as the operation status DR1 (DR2 ← DR1). Accordingly, the value stored as the inter-vehicle distance R2 is updated to the value stored as the inter-vehicle distance R1 (R2 ← R1). Next, in S163, and updates the information stored the information that is stored as operation status DR1 as operation situation _{Dd n (DR1 ← Dd n)} . Accordingly, the value stored as the inter-vehicle distance R1 is updated to a value stored as the inter-vehicle distance _{d n (R1 ← d n)} . That, is stored as a short operation situation DR1 operation status Dd _n is the most inter-vehicle distance, along with this, information stored as the operation status DR1, DR2 are sequentially rounded down to the operation status DR2, DR3, stored as operation status DR3 The operation status (the operation status with the longest inter-vehicle distance) that has been performed is deleted. Then, the inter-vehicle distance recording process ends.

In S164 the inter-vehicle distance d _n transitions is greater than the inter-vehicle distance R1, and compares the inter-vehicle distance d _n headway distance R2. Here, if the inter-vehicle distance d _n is larger than the inter-vehicle distance R2 proceeds to S167, if the inter-vehicle distance d _n is equal to or less than the inter-vehicle distance R2 proceeds to S165.

In S165, the same process as S161 is performed, and the information (including the inter-vehicle distance R3) stored as the operation status DR3 is updated to the information (including the inter-vehicle distance R2) stored as the operation status DR2 (DR3). ← DR2, R3 ← R2). Next, in S166, and updates the information stored the information that is stored as operation status DR2 as operation situation _{Dd n (DR2 ← Dd n)} . Accordingly, the value stored as the inter-vehicle distance R2 is updated to the value stored as the inter-vehicle distance _{d n (R2 ← d n)} . That is, operation status Dd _n stored as a short operation situation DR2 of the inter-vehicle distance is the second, Accordingly, information stored as the operation status DR2 is rounded down to the running condition DR3, it has been stored as the operation status DR3 The operation status (the operation status with the longest inter-vehicle distance) is deleted. Then, the inter-vehicle distance recording process ends.

In S167 the inter-vehicle distance d _n transitions is greater than the inter-vehicle distance R2, comparing the vehicle distance R3 and the inter-vehicle distance d _n. Here, the inter-vehicle distance d _n has finished large if the present inter-vehicle distance recording process than the inter-vehicle distance R3, if the inter-vehicle distance d _n is equal to or less than the inter-vehicle distance R3 proceeds to S168.

In S168, and updates the information stored the information that is stored as operation status DR3 as operation situation _{Dd n (DR3 ← Dd n)} . Accordingly, the value stored as the inter-vehicle distance R3 is updated to a value stored as the inter-vehicle distance _{d n (R3 ← d n)} . That is, operation status Dd _n is stored as a short operation situation DR3 of the inter-vehicle distance to the third, along with this, (long operation status of the most inter-vehicle distance) operation condition that has been stored as the operation status DR3 is erased. Then, the inter-vehicle distance recording process ends.

[1-3. effect]
According to the first embodiment described in detail above, the following effects can be obtained.
[1A] The operation status when the inter-vehicle distance falls below the warning threshold value Dth is recorded in the storage unit 23, and the operation manager can check the recorded operation status after driving. Specifically, when it is determined that the change over time in the inter-vehicle distance is due to an interruption of another vehicle, it is determined that it is not due to an interruption of the other vehicle and the operation status (operation status DR1, DR2, DR3). The operation status (operation status DS1, DS2, DS3) is identified and recorded (S150 to S158, S160 to S168).

  According to such a configuration, whether or not the factor that the inter-vehicle distance is shortened (the abnormal approach to the preceding vehicle has occurred) is an interruption of the other vehicle ahead of the host vehicle based on the recorded operation situation. Can be identified. In addition, the operation manager can perform appropriate safe driving guidance in consideration of the factors that shorten the inter-vehicle distance based on the recorded operation status.

[1B] When the difference between the front and rear vehicle distances (the inter-vehicle distance d _n-1 and the inter _- vehicle distance d _n ) below the warning threshold value Dth is greater than or equal to the first interrupt threshold value D, It is determined that the change is due to an interruption of another vehicle (S140). According to such a configuration, it is possible to easily identify whether or not the cause of the reduction in the inter-vehicle distance (the occurrence of abnormal approach to the preceding vehicle) is due to the interruption of another vehicle.

  [1C] When the time-dependent change in the inter-vehicle distance is not due to an interruption of another vehicle, the stored information (operation status) stored in the storage unit 23 is the inter-vehicle distance included in the operation status with the upper limit number stored as 3. Is updated so that the shorter is stored preferentially (S150 to S158). The same applies to the case where the change over time in the inter-vehicle distance is due to an interruption of another vehicle (S160 to S168).

  According to such a configuration, since it is presumed that a more dangerous driving operation was performed in an operation situation in which the inter-vehicle distance became shorter, storage information with a short inter-vehicle distance is preferentially stored in the storage unit 23. Can do. Moreover, according to such a structure, since it is not necessary to make an operation manager specify the operation condition considered that more dangerous driving operation was performed, the load of an operation manager can be reduced. In the present embodiment, the stored information in the storage unit 23 is output to the memory card 40. Although the memory card 40 has an upper limit on the storage capacity, according to such a configuration, information with high priority is stored in the memory card 40, so that the storage capacity of the memory card 40 can be used effectively.

  In the first embodiment, the digital tachograph 10 corresponds to an example of an “operation status recording device”. Further, S110 corresponds to an example of processing as “inter-vehicle distance acquisition means”, S120 corresponds to an example of processing as “warning determination means”, and S150 to S158 and S160 to S168 are processing as “recording means”. S140 corresponds to an example of processing as “interrupt determination means”. In addition, the upper limit number (3 in the present embodiment) of the operation status stored in the storage unit 23 corresponds to the “first upper limit value” and the “second upper limit value”.

[2. Second Embodiment]
[2-1. Difference from the first embodiment]
Since the basic configuration of the second embodiment is the same as that of the first embodiment, the description of the common configuration will be omitted, and the description will focus on the differences.

In the first embodiment described above, when the inter-vehicle distance d _n falls below the warning threshold Dth, on the basis of the difference between the inter-vehicle distance d _n-1 and the inter-vehicle distance d _n, temporal changes in the distance between the vehicles other It was determined whether or not the vehicle was interrupted (S140). In contrast, in the second embodiment, when the change over time in the inter-vehicle distance to determine whether it is due to the interruption of the other vehicle, instead of the difference between the inter-vehicle distance d _n-1 and the inter-vehicle distance d _n Te, the predicted value d _p headway distance d _n which is calculated based on a plurality of inter-vehicle distance obtained a plurality of times (including vehicle distance d _n-1) before the vehicle distance d _n, actually obtained This is different from the first embodiment in that a difference from the inter-vehicle distance d _n is used. Specifically, the contents of the inter-vehicle distance recording process executed by the CPU 51 are different.

FIG. 4A is a diagram illustrating an example of the predicted value d _{p in} the change over time in the inter-vehicle distance that is not caused by the interruption of another vehicle. The case where the inter-vehicle distance is less than (becomes shorter) than the warning threshold Dth is, as described above, a case where the driver of the own vehicle performs a driving operation that neglects the forward gaze due to a drowsy driving or the like. It is done. In this case, the inter-vehicle distance d _n plurality of inter-vehicle distance obtained a plurality of times before (for example, FIG. 4 (inter-vehicle distance from the inter-vehicle distance d _n-4 shown in a) d _n-1) is slowly It changes to be shorter. As described above, the inter-vehicle distance d _n-1 indicates the inter-vehicle distance detected one cycle before, as described above, the inter-vehicle distance d _n-2 is two cycles ago, the inter-vehicle distance d _n-3 is three cycles ago, The inter-vehicle distance dn _-4 indicates the inter-vehicle distance detected four cycles before.

Therefore, a plurality of times before the vehicle distance d _n (for example, three times) a plurality of inter-vehicle distance obtained over (e.g., between the distance d _n-3, the inter-vehicle distance d _n-2, the inter-vehicle distance d _n-3) Based on the rate of change, the predicted value d _p of the inter-vehicle distance that can be acquired next can be calculated. That is, when the actual inter-vehicle distance d _n to be acquired is a value within a predetermined range including the predicted value d _p (eg expected range Dw shown in FIG. 4 (a)), the time course of the following distance It can be determined that it is not due to an interruption of another vehicle.

Further, as a case where the inter-vehicle distance is less than (shortens) the warning threshold value Dth, for example, as described above, there is a case where an interruption of another vehicle is performed. In this case, the inter-vehicle distance d _n for a plurality of inter-vehicle distance obtained a plurality of times before the vehicle distance d _n (inter-vehicle distance d _n-4 inter-vehicle distance from d _n-1), for example, FIG. 4 As shown in FIG. 4B, it changes so as to be abruptly shorter than in the case of FIG. That is, the inter-vehicle distance d _n to be actually acquired, the inter-vehicle distance d _n multiple times before the plurality of inter-vehicle distance obtained over (3 times in this case) (in this case, between the distance d _n-3, the following distance d _n−2 , inter _- vehicle distance d _n−3 ) a value deviating from a predetermined range (here, the predicted range Dw shown in FIG. 4B) including the predicted value d _p calculated based on the rate of change. In this case, it is possible to determine that the change over time in the inter-vehicle distance is due to the interruption of another vehicle. In this way, it is different from the content of the inter-vehicle distance recording process in the first embodiment in that it is determined whether or not the change with time is due to an interruption of another vehicle.

[2-2. processing]
Next, the inter-vehicle distance recording process executed by the CPU 51 in the second embodiment will be described with reference to the flowchart of FIG. The process shown in FIG. 5 is executed at a predetermined cycle while the memory card 40 is inserted into the card interface unit 24, as in the first embodiment.

First, in S (step) 105, the value stored in the RAM 53 as the inter-vehicle distance d _n-3 is updated to the value stored in the RAM 53 as the inter-vehicle distance d _n-2 (d _n-3 ← d _{n -2} ), and updates the value stored in the RAM 53 as the inter _- vehicle distance d _n-2 to the value stored in the RAM 53 as the inter-vehicle distance d _n-1 (d _n-2 ← d _n-1 ). The value stored in the RAM 53 as the distance d _n−1 is updated to the value stored in the RAM 53 as the inter-vehicle distance d _n (d _n−1 ← d _n ). As described above, the inter-vehicle distance d _n−3 , the inter _- vehicle distance d _n−2 , and the inter-vehicle distance d _n−1 indicate the inter-vehicle distances detected three cycles before, two cycles before, and one cycle before, respectively, vehicle distance d _n indicates the following distance detected by the current cycle. At the start of the inter-vehicle distance recording process (before the process of S105 is executed), the inter-vehicle distance d _n−3 , the inter _- vehicle distance d _n−2 , the inter _- vehicle distance d _n−1 and the inter _- vehicle distance d _n are one cycle. The values based on the previous are stored in the RAM 53, and in S105, the values of the inter-vehicle distance dn _-3 , the inter _- vehicle distance dn _-2 , and the inter _- vehicle distance dn _-1 are updated so as to be shifted by one cycle.

Next, in S110 to S130, processing similar to that in the first embodiment is executed.
In subsequent S142, based on the (inter-vehicle distance d _n-3 ~ vehicle distance d _n-1 in this example) a plurality of inter-vehicle distance obtained over (3 times in this case) a plurality of predetermined times before the vehicle distance d _n calculating a predicted value d _p of the inter-vehicle distance d _n, or those temporal changes in the distance between the vehicles by the interrupt of the other vehicle by comparison actually the acquired vehicle distance d _n and the predicted value d _p calculated An interrupt determination process is performed to determine whether or not. In the interrupt determination process, if it is determined that the time-dependent change in the inter-vehicle distance is due to an interruption of another vehicle, the value of the interrupt flag F is updated to 1, and if it is determined not to be due to an interrupt, The value of the interrupt flag F is updated to 0.

  Next, in S144, based on the result of the interrupt determination process, when the value of the interrupt flag F is 1, the process proceeds to S150, and when the value of the interrupt flag F is not 1 (when 0), the process proceeds to S160. Transition.

  In subsequent S150 to S158 and S160 to S168, processing similar to that of the first embodiment is executed. That is, the shorter the inter-vehicle distance included in the operation status, the more preferentially stored, when the time-dependent change in the inter-vehicle distance is not due to the interruption of the other vehicle and the interruption due to the other vehicle. In addition, the operation status of the upper limit number (3 in the present embodiment) is stored in the storage unit 23. Then, the inter-vehicle distance recording process ends.

Next, the interrupt determination process executed in S142 of the inter-vehicle distance recording process will be described with reference to the flowchart of FIG.
In S205, based on the (inter-vehicle distance d _n-3 ~ vehicle distance d _n-1 in this example) a plurality of inter-vehicle distance obtained over (3 times in this case) a plurality of predetermined times before the vehicle distance d _n headway calculating a predicted value d _p of the distance d _n. Here, as an example, the predicted value d _p is calculated using the least square method based on the inter _- vehicle distance d _n−3 to the inter _- vehicle distance d _n−1 . However, the calculation method of the predicted value d _p is not limited to this.

Next, in S210, it is determined whether or not the change over time in the inter-vehicle distance is due to an interruption of another vehicle. That is, the inter-vehicle distance d _n is equal to or a value out of a predetermined range including the predicted value d _p (eg expected range Dw shown in Figure 4 (a)). Specifically, it is determined that the difference between the predicted value d _p actually acquired vehicle distance d _n of the inter-vehicle distance d _n is the interrupt when it is a second interrupt threshold E more. The second threshold value E is set to, for example, a value that is ½ of the prediction range Dw described above. Here, if the difference between the predicted value d _p and the inter-vehicle distance dn is _equal to or greater than the second interrupt threshold value E, the process proceeds to S215 and the value of the interrupt flag F is updated to 1. The interrupt determination process is terminated. On the other hand, _if the difference between the predicted value d _p and the inter-vehicle distance dn is less than the second interrupt threshold E value, the process proceeds to S220 and the value of the interrupt flag F is updated to 0, End the interrupt determination process.

[2-3. effect]
According to the second embodiment described above in detail, in addition to the effects [1A] and [1C] of the first embodiment described above, the following effects can be obtained.

When the [2A] vehicle distance falls below the warning threshold Dth, the difference between the predicted value d _p actually acquired vehicle distance between d _n of the inter-vehicle distance d _n is the second interrupt threshold E When this is the case, it is determined that the change over time in the inter-vehicle distance is due to an interruption of another vehicle (S210). According to such a configuration, it is possible to accurately identify whether or not the cause of the reduction in the inter-vehicle distance (the occurrence of abnormal approach to the preceding vehicle) is due to the interruption of the other vehicle.

  In the second embodiment, S142 to S144 correspond to an example of processing as “interrupt determination means”, S205 corresponds to an example of processing as “predicted value calculation means”, and S210 corresponds to “prediction determination means”. Corresponds to an example of the process.

[3. Other Embodiments]
As mentioned above, although embodiment of this invention was described, it cannot be overemphasized that this invention can take a various form, without being limited to the said embodiment.

  [3A] In the above embodiment, the case where the upper limit number of operation statuses stored in the storage unit 23 is 3 has been described as an example, but an upper limit number other than 3 may be used. Further, the upper limit number may not be provided.

[3B] In the above embodiment, the fact that the inter-vehicle distance has changed shortly across the warning threshold value Dth is a condition for recording the operation status in the storage unit 23 (S120), but is not limited to this. Absent. For example, the condition that the inter-vehicle distance d _n is less than the warning threshold value Dth may be a condition for recording the operation status in the storage unit 23.

The [3C] The second embodiment, as an example, a case of calculating a predicted value d _p headway distance d _n on the basis of a plurality of inter-vehicle distance obtained three times as a predetermined number of times before the vehicle distance d _n Although described, the predetermined number may be a number other than three.

  [3D] The functions of one component in the embodiment may be distributed as a plurality of components, or the functions of a plurality of components may be integrated into one component. Further, at least a part of the configuration of the above embodiment may be replaced with a known configuration having the same function. Moreover, you may abbreviate | omit a part of structure of the said embodiment as long as a subject can be solved. In addition, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of the other embodiment. In addition, all the aspects included in the technical idea specified from the wording described in the claims are embodiments of the present invention.

  [3E] In addition to the digital tachograph 10 described above, the present invention includes a control device as a component of the digital tachograph 10, a program for causing a computer to function as the control device, a medium on which the program is recorded, and an inter-vehicle distance recording method It can be realized in various forms.

  DESCRIPTION OF SYMBOLS 1 ... Operation condition recording system 13 ... Inter-vehicle distance measuring device 23 ... Memory | storage part 25 ... Control apparatus 51 ... CPU 52 ... ROM 53 ... RAM.

Claims (5)

An operation status recording device used in a vehicle,
Inter-vehicle distance acquisition means (S110) for acquiring the inter-vehicle distance between the host vehicle and the preceding vehicle;
Warning determination means (S120) for determining whether the inter-vehicle distance acquired by the inter-vehicle distance acquisition means is less than a predetermined warning threshold;
Recording means (S150 to S168) for recording the operation status of the host vehicle including the inter-vehicle distance when the warning determining means determines that the inter-vehicle distance is less than the warning threshold;
A first inter-vehicle distance that is determined to be less than the warning threshold by the warning determination means, and an inter-vehicle distance acquired by the inter-vehicle distance acquisition means before the first inter-vehicle distance. Interrupt judging means (S140, S142 to S144) for judging whether or not the change over time of the intervehicular distance is due to an interruption of another vehicle based on the second intervehicular distance;
With
The recording means includes the operation status including the first inter-vehicle distance determined by the interruption determination means that the temporal change is due to an interruption of another vehicle, and the temporal change is an interruption of the other vehicle. The operation status recording apparatus, wherein the operation status including the first inter-vehicle distance determined not to be recorded is identifiable. The operation status recording device according to claim 1,
The interrupt determination means (S140) determines that the temporal change is due to an interrupt when the difference between the first inter-vehicle distance and the second inter-vehicle distance is equal to or greater than a first interrupt threshold. It is determined that there is an operation status recording device. The operation status recording device according to claim 1,
The interrupt determination means (S142 to S144)
A predicted value of the first inter-vehicle distance is calculated based on a plurality of inter-vehicle distances including the second inter-vehicle distance acquired by the inter-vehicle distance acquisition unit a plurality of times before the first inter-vehicle distance. Predicted value calculation means (S205) to perform,
Prediction determination means (S210) for determining that the change over time is due to interruption when the difference between the first inter-vehicle distance and the predicted value is equal to or greater than a second interrupt threshold value;
An operation status recording device comprising: The operation status recording device according to any one of claims 1 to 3,
The recording means (S150 to S158) sets a first upper limit value as an upper limit for the operation status including the first inter-vehicle distance determined by the interrupt determination means that the change with time is not due to interruption. The operation status is recorded in the storage device such that the shorter the first inter-vehicle distance included in the operation status is stored in the storage device, the priority is stored in the storage device. Operation status recording device. The operation status recording device according to any one of claims 1 to 4,
The recording means (S160 to S168) sets a second upper limit value as an upper limit for the operation status including the first inter-vehicle distance determined by the interrupt determination means to be caused by interruption. The operation status is recorded in the storage device such that the shorter the first inter-vehicle distance included in the operation status is stored in the storage device, the priority is stored in the storage device. Operation status recording device.

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