JP2014038441A - Drive recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive recorder capable of improving accuracy in determination of a traveling state of a vehicle.SOLUTION: A drive recorder 1 temporarily stores image data 41 photographed by a camera 15. The drive recorder 1 acquires a position of a vehicle 50 by means of GPS and uses the acquired position to calculate a speed of the vehicle 50. If a measured acceleration measured by an acceleration sensor 14 is within a dangerous range set in a first determination table 43, the drive recorder 1 calculates an acceleration (calculated acceleration) of the vehicle 50 in a period of a prescribed time from a time (reference time) when the measured acceleration is within the dangerous range. If the calculated acceleration is higher than a threshold set in a second determination table 44, the drive recorder 1 designates image data photographed in a storage period including the reference time, as a transmission object.

Description

  The present invention relates to a drive recorder, and more particularly to a drive recorder that acquires acceleration of a vehicle.

  A drive recorder is a device that records image data obtained by capturing a scene in front of a vehicle such as an automobile. By using the data recorded by the drive recorder, the cause of the traffic accident can be easily identified. By installing the drive recorder in the vehicle, there is also an advantage that the driver's awareness about safe driving is improved.

  When all the image data photographed by the drive recorder is stored, the capacity of the storage device built in the drive recorder is pressed. When the drive recorder transmits all captured image data to a server or the like, the communication band is compressed. Therefore, when the drive recorder detects an acceleration exceeding a predetermined threshold, the drive recorder determines that the vehicle is in a dangerous situation, and saves or transmits image data captured during a period including the time.

  However, when the vehicle simply passes through a step on the road, acceleration exceeding a predetermined threshold may be detected. In this case, the drive recorder erroneously determines that the detected acceleration is an impact caused by a traffic accident or dangerous driving. As described above, when the drive recorder erroneously determines the traveling state of the vehicle, image data unrelated to a traffic accident or dangerous driving is stored.

  Patent Document 1 describes a drive recorder that determines whether or not a detected impact has occurred due to a step on the road surface when an impact is detected.

  In Patent Document 1, the drive recorder holds road impact position information in which the position of a road step is recorded. When the drive recorder detects an impact, the drive recorder confirms whether the position where the impact is detected is within a predetermined range from the position registered in the road surface impact position information. When the position where the impact is detected is not within the predetermined range, the drive recorder stores video information and the like at the time when the impact is detected. On the other hand, when the position where the impact is detected is within the predetermined range, the drive recorder does not save the video information at the time when the impact is detected. However, when the vehicle passes through a step that is not registered in the road surface impact position information, the traveling state of the vehicle is erroneously determined.

JP 2009-87274 A JP 2010-61881 A

  The objective of this invention is providing the drive recorder which can improve the precision which determines the driving | running | working condition of a vehicle.

Means and effects for solving the problems

  The drive recorder of the present invention includes a collection unit, an acceleration acquisition unit, a position acquisition unit, a speed calculation unit, a first acceleration determination unit, an acceleration calculation unit, a second acceleration determination unit, and a target specification unit. Prepare. The collection unit collects image data obtained by capturing a scene outside or inside the vehicle. The acceleration acquisition unit acquires the first acceleration of the vehicle measured by the acceleration sensor. The first acceleration determination unit determines whether or not the magnitude of the first acceleration acquired by the acceleration acquisition unit is greater than a first threshold value. The position acquisition unit acquires the position of the vehicle using a satellite positioning system. The speed calculation unit calculates the vehicle speed using the newly acquired vehicle position and the vehicle position acquired immediately before by the position acquisition unit when the position acquisition unit acquires a new vehicle position. To do. When the first acceleration determination unit determines that the magnitude of the acquired first acceleration is greater than the first threshold, the acceleration calculation unit calculates the second acceleration at a predetermined time after that time as a speed calculation unit. Calculate based on the speed calculated by. The second acceleration determination unit determines whether or not the second acceleration calculated by the acceleration calculation unit is greater than a second threshold value. Specifically, it is determined whether at least one of the magnitude and direction of the second acceleration is larger than the second threshold value. When the second acceleration determining unit determines that the second acceleration is greater than the second threshold, the target designating unit is photographed during a predetermined storage period including time among the image data collected by the collecting unit. Specified image data to be saved.

  According to the present invention, the drive recorder calculates the speed of the vehicle using the position of the vehicle acquired using the satellite positioning system. When the first acceleration measured by the acceleration sensor is larger than the first threshold value, the drive recorder uses the vehicle speed to calculate the second acceleration of the vehicle in a predetermined period including the time, and the second acceleration. Is greater than the second threshold value. In order to specify image data to be stored using not only the first acceleration measured by the acceleration sensor but also the second acceleration calculated based on the position of the vehicle, the drive recorder of the present invention is capable of The determination accuracy can be improved.

  Preferably, the second threshold value includes a magnitude threshold value indicating a reference for the magnitude of acceleration. The second acceleration determining unit determines whether or not the magnitude of the second acceleration is larger than a magnitude threshold value. The object designating unit designates image data to be stored when the second acceleration determining unit determines that the magnitude of the second acceleration is larger than the magnitude threshold value.

  According to the present invention, when it is determined that the magnitude of the second acceleration is larger than the magnitude threshold, the drive recorder designates image data to be saved. As a result, it is possible to save the image data captured when the speed of the vehicle (the magnitude of the speed) changes abruptly.

  Preferably, the second threshold value includes a direction threshold value indicating a reference for the direction of acceleration. The second acceleration determining unit determines whether or not the direction of the second acceleration is greater than the direction threshold value. The object designating unit designates image data to be stored when the second acceleration determining unit determines that the direction of the second acceleration is larger than the direction threshold value.

  According to the present invention, the drive recorder designates image data to be saved when it is determined that the direction of the second acceleration is larger than the direction threshold value. As a result, it is possible to save the image data captured when the direction of the speed of the vehicle changes abruptly.

  Preferably, the drive recorder of the present invention further includes an azimuth measuring unit and a difference determining unit. The azimuth measuring unit measures the azimuth in the front direction of the vehicle. The difference determining unit calculates the azimuth and velocity calculated by the azimuth measuring unit when the second acceleration determining unit determines that the second acceleration calculated by the acceleration calculating unit is smaller than the second threshold value. It is determined whether or not the difference from the speed direction is greater than a predetermined angle. The object designating unit designates image data to be stored when the difference determining unit determines that the difference is larger than a predetermined angle.

  According to the present invention, the drive recorder designates image data to be stored when the difference between the vehicle forward direction and the vehicle speed direction calculated from the position acquired by the position acquisition unit is larger than a predetermined angle. To do. As a result, it is possible to save image data captured when the moving direction of the vehicle greatly deviates from the front direction of the vehicle due to the slipping of the vehicle.

  The program of the present invention is used for the drive recorder of the present invention.

  The vehicle travel data storage method of the present invention is used in the drive recorder and program of the present invention.

It is a functional block diagram which shows the structure of the drive recorder which concerns on embodiment of this invention. It is a figure explaining the attachment method of the drive recorder shown in FIG. It is a figure which shows the direction of the acceleration measured by the acceleration sensor shown in FIG. It is a flowchart of the recording process performed by the recorder program shown in FIG. It is a flowchart of the image transmission process performed by the recorder program shown in FIG. It is a figure explaining the calculation method of the speed by the recorder program shown in FIG. It is a figure which shows the 1st determination table shown in FIG. It is a graph which shows the time change of the acceleration measured by the acceleration sensor shown in FIG. It is a flowchart of the calculation acceleration determination process shown in FIG. It is a figure which shows transition of the speed of the vehicle in which the drive recorder shown in FIG. 1 is installed. It is a graph which shows the change of the magnitude | size of the speed shown in FIG. It is a figure which shows the change of the direction of the speed shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

{overall structure}
FIG. 1 is a functional block diagram of a drive recorder 1 according to an embodiment of the present invention. Referring to FIG. 1, a drive recorder 1 is a computer such as a smartphone, a mobile phone, or a tablet terminal. The drive recorder 1 can communicate with the management server 3 by accessing the Internet 2 via a mobile phone communication network or a wireless LAN (Local Area Network).

  The drive recorder 1 captures a scene in front of the vehicle, generates image data 41, and designates the image data 41 captured during the transmission target period as a storage target to be stored in the management server 3. The drive recorder 1 transmits image data 41 taken during the transmission target period to the management server 3. The management server 3 stores the transmitted image data 41 in the storage device 31. The setting of the transmission target period will be described later.

  Hereinafter, the configuration of the drive recorder 1 will be described. Referring to FIG. 1, a drive recorder 1 includes a CPU (Central Processing Unit) 10, a RAM (Random Access Memory) 11, a display panel 12, a touch panel 13, an acceleration sensor 14, a camera 15, and an electronic compass. 16, a GPS (Global Positioning System) antenna 17, a memory 18, and a wireless communication unit 19.

  The CPU 10 controls the drive recorder 1 by executing a program loaded in the RAM 11. The RAM 11 is a main memory of the drive recorder 1.

  The display panel 12 is a liquid crystal panel or the like, and displays an image taken by the camera 15. The touch panel 13 is installed on the display panel 12 and outputs the position touched by the user as operation information.

  The acceleration sensor 14 measures the acceleration of the drive recorder 1. That is, the acceleration sensor 14 measures the acceleration of the vehicle on which the drive recorder 1 is installed. The camera 15 creates image data 41 by photographing the situation outside or inside the vehicle. The electronic compass 16 measures the front direction of the vehicle. The GPS antenna 17 receives a signal transmitted from a GPS satellite.

  The memory 18 is a non-volatile flash memory. The memory 18 stores a recorder program 40, image data 41, numerical data 42, a first determination table 43, and a second determination table 44.

  The recorder program 40 is a program for causing a computer to function as a drive recorder. The user can use the computer as the drive recorder 1 by installing the recorder program 40 on a computer such as a smartphone. Details of the operation of the recorder program 40 will be described later.

  The image data 41 is data taken by the camera 15 and is temporarily stored in the memory 18. The numerical data 42 is information in which numerical values such as the position, speed, and acceleration of the vehicle are recorded in time series. The image data 41 is vehicle travel data indicating the travel status of the vehicle. The vehicle travel data may include numerical data 42.

  The first determination table 43 and the second determination table 44 are used for determining whether or not to transmit the image data 41 temporarily stored in the memory 18 to the management server 3. Details of the first determination table 43 and the second determination table 44 will be described later.

{Outline of operation of drive recorder 1}
Hereinafter, an outline of the operation of the recorder program 40 will be described.

  The recorder program 40 collects image data 41 taken by the camera 15 and temporarily stores the collected image data 41 in the memory 18. The recorder program 40 acquires the vehicle acceleration (measured acceleration) measured by the acceleration sensor 14 and acquires the position of the vehicle using the signal received by the GPS antenna 17. When the position of the vehicle is newly acquired, the recorder program 40 calculates the speed of the vehicle using the position of the newly acquired vehicle and the position of the vehicle acquired immediately before. The measured acceleration, the vehicle position, and the speed are recorded in the numerical data 42 in time series.

  The recorder program 40 determines whether or not the measured acceleration is within the acceleration range (danger range) recorded in the first determination table 43. When the recorder program 40 determines that the measured acceleration is within the danger range, the recorder program 40 calculates the acceleration (calculated acceleration) during the period from the time when the measured acceleration is within the danger range (reference time) until a predetermined time elapses. Calculate using speed. That is, the calculated acceleration is calculated from the position of the vehicle based on GPS.

  The recorder program 40 determines whether or not the calculated acceleration is greater than a threshold value set in the second determination table 44. In the second determination table 44, a magnitude threshold value indicating a reference for the magnitude of acceleration and a direction threshold value indicating the reference for the direction of acceleration are set. If at least one of the magnitude and direction of the calculated acceleration is greater than the threshold value set in the second determination table 44, the recorder program 40 determines that a traffic accident has occurred or that dangerous driving has been performed. To do. The recorder program 40 designates, among the image data 41 temporarily stored in the memory 18, the image data 41 captured during the transmission target period including the reference time as the transmission target. In the present embodiment, the image data 41 specified as the transmission target is stored in the management server 3 by specifying the image data 41 captured during the transmission target period as the transmission target.

  The recorder program 40 can improve the determination accuracy of the traveling state of the vehicle by using the measured acceleration measured by the acceleration sensor 14 and the calculated acceleration calculated from the position of the vehicle. Therefore, the recorder program 40 can selectively transmit the image data 41 taken when a traffic accident involving the vehicle occurs or when the user performs a dangerous driving to the management server 3.

{Details of drive recorder 1}
Hereinafter, the mounting and operation of the drive recorder 1 will be described in detail.

{Installation of drive recorder 1}
FIG. 2 is a diagram showing the drive recorder 1 fixed to the vehicle 50. The user attaches the drive recorder 1 to the vehicle 50 before driving the vehicle 50.

  Referring to FIG. 2, cradle 52 is fixed on dashboard 51 of vehicle 50. The position where the cradle 52 is fixed is a position where the drive recorder 1 and the cradle 52 do not interfere with the driver's view. The user fits the drive recorder 1 in the cradle 52 fixed on the dashboard 51. Thereby, the drive recorder 1 is attached to the vehicle 50. At this time, the drive recorder 1 is fitted into the cradle 52 so that the camera 15 can photograph the front of the vehicle 50.

  The camera 15 is attached to a surface opposite to the surface on which the display panel 12 is arranged in the housing 100 of the drive recorder 1. Accordingly, the driver can easily confirm that the drive recorder 1 is operating while sitting on the seat 53.

  Note that the drive recorder 1 may be attached to the vehicle 50 so that the camera 15 faces the rear of the vehicle 50 in order to capture the rear seat of the vehicle 50 and the scenery behind the vehicle 50. That is, the drive recorder 1 should just be installed in the vehicle 50 so that the camera 15 can image the situation outside or inside the vehicle 50.

  FIG. 3 is a diagram showing the acceleration detection direction of the drive recorder 1 when the camera 15 is installed so as to photograph the front of the vehicle 50. With reference to FIG. 3, measured accelerations Ax, Ay, Az are measured by the acceleration sensor 14. The measured acceleration Ax indicates the acceleration in the forward direction of the vehicle 50. The measured acceleration Ay indicates the acceleration in the turning direction of the vehicle 50. The measured acceleration Az indicates the acceleration of the vehicle 50 in the gravity direction. Hereinafter, when the measurement accelerations Ax, Ay, and Az are collectively referred to, these accelerations are simply referred to as “measurement acceleration”.

  The electronic compass 16 measures the front direction of the vehicle 50. The electronic compass 16 outputs the forward direction as a clockwise angle with respect to the north.

{Operation of recorder program 40}
FIG. 4 is a flowchart of the recording process executed by the recorder program 40. FIG. 5 is a flowchart of image transmission processing executed by the recorder program 40. First, the driver operates the drive recorder 1 attached to the vehicle 50 to start the recorder program 40. The activated recorder program 40 activates the camera 15 and executes recording processing and image transmission processing in parallel.

{Recording process}
Hereinafter, the recording process will be described with reference to FIG. The recording process is a process of collecting image data taken by the camera 15 and recording the position and speed of the vehicle 50 in the numerical data 42.

  When the recorder program 40 acquires the image data 41 taken by the camera 15 (Yes in step S201), the recorder program 40 temporarily stores the acquired image data 41 in the memory 18 in association with the current time (step S202). . On the other hand, when the recorder program 40 does not acquire the image data 41 (No in step S201), the recorder program 40 proceeds to step S203.

  When the recorder program 40 newly acquires a position from the signal received by the GPS antenna 17 (Yes in step S203), the recorder program 40 calculates the speed V of the vehicle 50 using the newly acquired position and the position acquired immediately before. (Step S204). The position acquired immediately before is recorded in the numerical data 42.

  FIG. 6 is a diagram for explaining a method of calculating the vehicle speed V. FIG. The position of the vehicle 50 is represented by latitude and longitude coordinates. It is assumed that the position of the vehicle 50 at time t1 is p1 (x1, y1). Assume that the position of the vehicle 50 at time t2 is p2 (x2, y2). x1 and x2 are longitudes. y1 and y2 are latitudes. The recorder program 40 calculates the position vector P by obtaining the relative position of the position p2 viewed from the position p1. The recorder program 40 calculates the speed V of the vehicle 50 at the time t2 by dividing the position vector P by the time Δt from the time when the position p1 is acquired until the position p2 is acquired. The magnitude of the speed V corresponds to the speed of the vehicle 50, and the direction of the speed V corresponds to the moving direction of the vehicle 50. The direction of the velocity V is represented by a clockwise angle with respect to the north as in the forward direction indicated by the electronic compass 16.

  The recorder program 40 records the position p2 and the speed V in the numerical data 42 in association with the time t2 (step S205). On the other hand, when the recorder program 40 does not acquire a position (No in step S203), the recorder program 40 proceeds to step S206.

  When the recorder program 40 acquires the forward direction from the electronic compass 16 (Yes in step S206), the recorder program 40 records the acquired direction in the numerical data 42 in association with the current time (step S207). On the other hand, if the recorder program 40 does not acquire an orientation (No in step S206), the recorder program 40 proceeds to step S208.

  When the recorded acceleration is acquired from the acceleration sensor 14 (Yes in step S208), the recorder program 40 records the acquired measured acceleration in the numerical data 42 in association with the current time (step S209). On the other hand, when the recorder program 40 does not acquire the measured acceleration (No in step S208), the recorder program 40 proceeds to step S210.

  The recorder program 40 repeatedly executes steps S201 to S209 until the end is instructed (Yes in step S210).

{Image transmission processing}
Hereinafter, image transmission processing will be described with reference to FIGS. 5, 7, and 8. In the image transmission process, image data 41 related to a traffic accident or dangerous driving is designated as a transmission target for transmission to the management server 3 from the image data 41 photographed by the camera 15, and the designated image data 41 is designated. This is processing to be transmitted to the management server 3. Thereby, the image data 41 designated as a transmission target is stored in the management server 3.

  FIG. 7 is a diagram illustrating the first determination table 43. FIG. 8 is a graph showing the time change of the measured acceleration Ax. In the image transmission process, the recorder program 40 repeatedly executes the processes of steps S2 to S8 until instructed by the user to end (Yes in step S1).

  When the recorded acceleration is acquired from the acceleration sensor 14 (Yes in Step S2), the recorder program 40 determines whether or not the acquired measured acceleration is within the danger range set in the first determination table 43 (Step S2). S3).

  In the first determination table 43, the danger ranges are set in the forward direction, the turning direction, and the gravity direction, respectively. The acceleration that is assumed to be detected when a traffic accident occurs or when dangerous driving (such as sudden steering or braking) is set as the dangerous range.

  In FIG. 7, the threshold value of the danger range in each direction is the same, but the danger range in each direction may be different. Alternatively, in the first determination table 43, a danger range corresponding to a combined acceleration obtained by combining accelerations in the forward direction, the preceding direction, and the gravity direction may be set. In this case, the recorder program 40 may compare the acceleration obtained by combining the measured accelerations Ax, Ay, Az with the danger range.

  When any of the measured accelerations Ax, Ay, and Az is within the danger range (Yes in Step S3), the recorder program 40 determines that the vehicle has received a strong impact and executes the calculated acceleration determination process (Step S4). To do. In the calculated acceleration determination process (step S4), the calculated acceleration in a period (confirmation period) from the reference time until a predetermined time (for example, 10 seconds) elapses is larger than the threshold set in the second determination table 44. This is a process for determining whether the value is large. When the calculated acceleration is larger than the threshold value set in the second determination table 44, the recorder program 40 determines that the vehicle is likely to be in a dangerous situation, and sets the transmission target period. Details of the calculated acceleration determination process (step S4) will be described later.

  With reference to FIG. 8, the relationship between the reference time, the confirmation period, and the transmission target period will be described. Assume that the recorder program 40 determines that the measured acceleration Ax measured at time Tp is within the danger range. Time Tq is a time 10 seconds after time Tp. Time Tr is a time 5 seconds before time Tp. Time Ts is a time 5 seconds after time Tp. In this case, time Tp is the reference time, and a period from time Tp to time Tq is the confirmation period. When the calculated acceleration in the confirmation period is larger than the threshold value set in the second determination table 44, the period from time Tr to time Ts is set as the transmission target period. Note that the start time (time Tr) and end time (time Ts) of the transmission target period may be changed. The end time (time Tq) of the confirmation period may be changed. That is, the lengths of the transmission target period and the confirmation period are not limited to 10 seconds, respectively.

  On the other hand, if any of the measured accelerations Ax, Ay, Az is not within the danger range (No in step S3), the recorder program 40 returns to step S1.

  The recorder program 40 determines whether or not the transmission target period has been set by the calculated acceleration determination process (step S4) (step S5).

  When the transmission target period is set (Yes in step S5), the recorder program 40 determines whether the confirmation period has elapsed (step S6). When the confirmation period has elapsed (Yes in step S6), the recorder program 40 designates, among the image data 41 temporarily stored in the memory 18, the image data 41 captured during the transmission target period as the transmission target. (Step S7). The recorder program 40 transmits the image data 41 designated as the transmission target to the management server 3 (step S8).

  On the other hand, when the transmission target period is not set in step S5 (No in step S5), the recorder program 40 determines that the measured acceleration measured at time Tp is unrelated to a traffic accident or dangerous driving. Return to step S1.

{Calculated acceleration determination processing (step S4)}
Hereinafter, the calculated acceleration determination process (step S4) will be described in detail. As described above, when the measured acceleration measured by the acceleration sensor 14 is within the danger range (Yes in step S3), the calculated acceleration determination process (step S4) is started.

  FIG. 9 is a flowchart of the calculated acceleration determination process (step S4). Referring to FIG. 9, recorder program 40 uses the signal received by GPS antenna 17 to acquire the position of vehicle 50 at reference time Tp (step S401). The recorder program 40 calculates the speed at the reference time Tp using the position at the reference time Tp and the position acquired immediately before (step S402). The calculation of the speed is the same as that in step S204 (see FIG. 4).

  The recorder program 40 determines whether the confirmation period has elapsed (step S403). If the confirmation period has elapsed (Yes in step S403), the recorder program 40 ends the calculated acceleration determination process (step S4).

  On the other hand, if the confirmation period has not elapsed (No in step S403), the recorder program 40 confirms whether or not the position of the vehicle 50 has been newly acquired (step S404). If the recorder program 40 has not newly acquired the position of the vehicle 50 (No in step S404), the recorder program 40 returns to step S403.

  When the recorder program 40 newly acquires the position of the vehicle 50 (Yes in step S404), the recorder program 40 calculates the speed of the vehicle 50 using the newly acquired position and the position acquired immediately before (step S405). . The recorder program 40 calculates the calculated acceleration using the newly calculated speed and the speed calculated immediately before (step S406). Specifically, the recorder program 40 calculates a change in speed per unit time and a change in direction of speed per unit time as the calculated acceleration.

  FIG. 10 is a diagram showing a change in the speed of the vehicle 50. Referring to FIG. 10, it is assumed that the speed at the reference time (time Tp) is speed V0. The speeds at times Ta and Tb are assumed to be speeds Va and Vb, respectively. Times Ta and Tb are times within the confirmation period. The recorder program 40 calculates in the order of speeds V0, Va, Vb,. The vector F indicates the forward direction of the vehicle 50 at the reference time Tp, and the size is not particularly limited.

  FIG. 11 is a graph showing changes in speed. FIG. 12 is a graph showing changes in the direction of the velocity V. 9 to 12, in step S406, the recorder program 40 calculates the absolute value of the value obtained by subtracting the speed V0 from the speed Va as the speed change ΔVa. The recorder program 40 calculates the speed direction change Δθa by subtracting the direction of the speed V0 from the direction of the speed Va. Here, the azimuth indicates a clockwise angle with respect to the north.

  Assuming that the recorder program 40 acquires the position of the vehicle 50 every second, the speed change ΔVa corresponds to the magnitude of the calculated acceleration, and the direction change Δθa corresponds to the direction of the calculated acceleration. The speed change ΔVa is equal to or smaller than the magnitude threshold set in the second determination table 44, and the direction change Δθa is equal to or smaller than the direction threshold set in the second determination table 44. Assume.

  The recorder program 40 refers to the second determination table 44 to confirm whether or not the speed change ΔVa is larger than the magnitude threshold and the direction change Δθa is larger than the direction threshold (step). S407). Since the speed change ΔVa is equal to or smaller than the magnitude threshold value and the direction change Δθa is equal to or smaller than the direction threshold value (No in step S407), the recorder program 40 proceeds to step S408.

  The recorder program 40 checks whether or not the speed change ΔVa is larger than the magnitude threshold value and the direction change Δθa is less than or equal to the direction threshold value (step S408). Since the speed change ΔVa is equal to or smaller than the magnitude threshold value (No in step S408), the recorder program 40 proceeds to step S409.

  The recorder program 40 checks whether or not the speed change ΔVa is equal to or smaller than the magnitude threshold value and the direction change Δθa is larger than the direction threshold value (step S409). Since the change Δθa in the direction is equal to or less than the direction threshold value (No in step S409), the recorder program 40 has greatly changed the behavior of the vehicle 50 due to the measured acceleration measured at the time Tp at the time Ta. It determines with there not being, and progresses to step S410.

  Referring to FIGS. 9 and 10, recorder program 40 calculates difference ΔθF between the forward direction of vehicle 50 (the direction of vector F) and the direction of speed Va (step S410). When the difference ΔθF is larger than a predetermined angle set in advance (Yes in step S411), the recorder program 40 sets a transmission target period (step S412), and ends the calculated acceleration determination process (step S4).

  The reason why the difference ΔθF is compared with the predetermined angle in step S411 will be described. When the vehicle 50 is traveling on a snowy road, the vehicle 50 may slip. At this time, the actual moving direction of the vehicle 50 (direction of the speed V) may deviate greatly from the forward direction of the vehicle 50 (direction of the vector F). However, since the vehicle 50 often travels at low speed on snowy roads, there is a possibility that slip cannot be detected by the processing in steps S407 to S409 using the change in speed and the change in direction. For this reason, in steps S410 and S411, the slip of the vehicle 50 can be detected by comparing the difference ΔθF with a predetermined angle. For example, the predetermined angle is set to 45 degrees.

  On the other hand, if ΔθF at time Ta is equal to or smaller than the predetermined angle in step S411 (No in step S411), the recorder program 40 determines that there is no deviation between the forward direction of the vehicle 50 and the actual movement direction due to slip. Then, the process returns to step S403.

  Subsequently, the recorder program 40 calculates a speed Vb at time Tb (step S405). 9 to 12, in step S406, the recorder program 40 calculates an absolute value of a value obtained by subtracting the speed Va from the speed Vb as a speed change ΔVb. The recorder program 40 calculates the speed direction change Δθb by subtracting the direction of the speed Va from the direction of the speed Vb. Assume that the speed change ΔVb is greater than the magnitude threshold and the direction change Δθb is greater than the direction threshold.

  Since the speed change ΔVb is larger than the magnitude threshold value and the direction change Δθb is larger than the direction threshold value (Yes in step S407), the recorder program 40 sets a transmission target period (step S412). . Since the speed change ΔVb and the direction change Δθb have changed greatly after the measurement acceleration in the danger range is detected, a traffic accident involving the vehicle 50 has occurred at the reference time Tp, or It is highly probable that dangerous driving was performed. Therefore, the recorder program 40 sets a transmission target period in order to transmit the image data 41 to the management server 3 (step S412).

  The recorder program 40 sets the transmission target period even when the speed change ΔVb is larger than the magnitude threshold and the direction change Δθb is equal to or smaller than the direction threshold (Yes in step S408) (step S408). S412). In this case, since it is considered that the driver suddenly applied the brakes or suddenly started the vehicle 50, the recorder program 40 sets the transmission target period so that the traveling state of the vehicle 50 can be confirmed later. .

  The recorder program 40 sets the transmission target period even when the speed change ΔVb is equal to or smaller than the magnitude threshold value and the direction change Δθb is larger than the direction threshold value (Yes in step S409) (step S412). ). In this case, since it is considered that the driver has suddenly steered, the recorder program 40 sets a transmission target period.

  As described above, when the transmission target period is set in the calculated acceleration determination process (step S4), the recorder program 40 transmits the transmission target period in the image data 41 captured by the camera 15, as shown in FIG. The image data 41 taken is designated (steps S7 and S8).

  As described above, when it is determined that the measured acceleration is in the danger range at the time Tp, the recorder program 40 sets at least one of the magnitude and direction of the calculated acceleration in the confirmation period in the second determination table 44. Check if the threshold is exceeded. That is, the recorder program 40 can improve the determination accuracy of the traveling state of the vehicle 50 by using acceleration acquired by two different methods. As a result, it is possible to prevent the image data 41 irrelevant to a traffic accident or dangerous driving from being transmitted to the management server 3.

  In the said embodiment, the recorder program 40 demonstrated the example which acquires the position of the vehicle 50 for every second. However, the interval for acquiring the position of the vehicle may not be regular. In this case, the recorder program 40 may acquire the calculated acceleration by obtaining a change in speed per unit time in step SS406 (see FIG. 9). For example, when the interval between the times Ta and Tb is 2 seconds, the recorder program 40 can obtain the calculated acceleration at the time Tb by dividing ΔVb by 2. That is, the recorder program 40 may calculate the acceleration using the position of the vehicle acquired using GPS in step S406.

  In the above embodiment, an example has been described in which the recorder program 40 determines whether or not the measured acceleration is within the danger range (step S3, see FIG. 5). The recorder program 40 may determine whether or not the magnitude of the measured acceleration is larger than the threshold value set in the first determination table 43 in step S3.

  In the above embodiment, an example in which the recorder program 40 designates an example in which the image data 41 taken during the transmission target period is transmitted to the management server 3 has been described (see step S8, FIG. 5). However, the recorder program 40 may manage the image data 41 captured during the transmission target period so that the image data 41 is not deleted from the memory 18 without being transmitted to the management server 3. That is, the recorder program 40 sets a storage period for designating the image data 41 stored in the memory 18 or the management server 3 when the calculated acceleration is larger than the threshold value set in the second determination table 44. The image data 41 taken during the storage period may be designated as a storage target.

  In the above embodiment, whether or not the recorder program 40 has at least one of a change in speed and a change in direction in the recording process (see Steps S4 and 9) larger than a threshold set in the second determination table. The example of determining whether or not was described (steps S407 to S409). However, the recorder program 40 may determine in steps S407 to S409 whether at least one of the change in speed and the change in direction is equal to or greater than a threshold value set in the second determination table. The recorder program 40 may execute step S410 when at least one of the change in speed and the change in direction is smaller than the threshold value set in the second determination table.

  In the above embodiment, the example in which the recorder program 40 is installed in a portable computer such as a smartphone has been described, but the present invention is not limited to this. The drive recorder 1 may be a dedicated device instead of a general-purpose device such as a smartphone.

  In the said embodiment, the example in which the recorder program 40 was installed in the smart phone etc. was demonstrated. A method for installing the recorder program 40 is not particularly limited. For example, the recorder program 40 may be downloaded from a server connected to a network and installed on a smartphone or the like. Alternatively, when a computer-readable medium (for example, an optical disk, a USB (Universal Serial Bus) memory, a flexible disk, etc.) on which the recorder program 40 is recorded is distributed, the recorder program 40 is installed on the tablet terminal from the medium. May be.

  While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and can be implemented by appropriately modifying the above-described embodiment without departing from the spirit thereof.

1 Drive recorder 10 CPU
11 RAM
14 acceleration sensor 15 camera 16 electronic compass 17 GPS antenna 40 recorder program 41 image data 42 numerical data 43 first determination table 44 second determination table 50 vehicle

Claims (6)

A collection unit that collects image data of the scenery outside or inside the vehicle;
An acceleration acquisition unit for acquiring a first acceleration of the vehicle measured by an acceleration sensor;
A first acceleration determination unit that determines whether or not the magnitude of the first acceleration acquired by the acceleration acquisition unit is greater than a first threshold;
A position acquisition unit that acquires the position of the vehicle using a satellite positioning system;
When the position of the vehicle is newly acquired by the position acquisition unit, the speed of the vehicle is calculated based on the newly acquired position of the vehicle and the position of the vehicle acquired immediately before by the position acquisition unit. A speed calculator to calculate,
When the first acceleration determination unit determines that the magnitude of the acquired first acceleration is greater than the first threshold value, the second acceleration at a predetermined time after that time is calculated by the speed calculation unit. An acceleration calculator that calculates based on the calculated velocity;
A second acceleration determining unit that determines whether or not the second acceleration calculated by the acceleration calculating unit is greater than a second threshold;
When the second acceleration determination unit determines that the second acceleration is greater than the second threshold value, the image data collected by the collection unit is captured during a predetermined storage period including the time. A drive recorder comprising: a target designating unit that designates the image data as a storage target. The drive recorder according to claim 1,
The second threshold value includes a magnitude threshold value indicating a standard of magnitude of acceleration,
The second acceleration determining unit determines whether the magnitude of the second acceleration is greater than the magnitude threshold;
The target designation unit designates image data to be saved when the second acceleration determination unit determines that the magnitude of the second acceleration is larger than the magnitude threshold. The drive recorder according to claim 1 or 2,
The second threshold includes a direction threshold indicating a reference for the direction of acceleration;
The second acceleration determination unit determines whether the direction of the second acceleration is larger than the direction threshold value,
The target specifying unit specifies image data to be stored when the second acceleration determining unit determines that the direction of the second acceleration is larger than the direction threshold value. The drive recorder according to any one of claims 1 to 3, further comprising:
An azimuth measuring unit for measuring the azimuth in the front direction of the vehicle;
When the second acceleration determination unit determines that the second acceleration is smaller than the second threshold, the direction measured by the direction measurement unit and the direction of the speed calculated by the speed calculation unit A difference determination unit that determines whether or not the difference is larger than a predetermined angle;
The target specifying unit is a drive recorder that specifies image data to be stored when the difference determination unit determines that the difference is larger than the predetermined angle. In the computer installed in the drive recorder,
Collecting image data of a scene outside or inside the vehicle;
Obtaining a first acceleration of the vehicle measured by an acceleration sensor;
Determining whether the magnitude of the acquired first acceleration is greater than a first threshold;
Obtaining the position of the vehicle using a satellite positioning system;
When the position of the vehicle is newly acquired, calculating the speed of the vehicle based on the newly acquired position of the vehicle and the position of the vehicle acquired immediately before;
Calculating the second acceleration at a predetermined time after that time based on the calculated speed when it is determined that the magnitude of the acquired first acceleration is greater than the first threshold; ,
Determining whether the calculated second acceleration is greater than a second threshold;
When it is determined that the second acceleration is greater than the second threshold value, the step of designating, among the collected image data, image data captured during a predetermined storage period including the time as a storage target A program to execute and. Collecting image data of a scene outside or inside the vehicle;
Obtaining a first acceleration of the vehicle measured by an acceleration sensor;
Determining whether the magnitude of the acquired first acceleration is greater than a first threshold;
Obtaining the position of the vehicle using a satellite positioning system;
When the position of the vehicle is newly acquired, calculating the speed of the vehicle based on the newly acquired position of the vehicle and the position of the vehicle acquired immediately before;
Calculating the second acceleration at a predetermined time after that time based on the calculated speed when it is determined that the magnitude of the acquired first acceleration is greater than the first threshold; ,
Determining whether the calculated second acceleration is greater than a second threshold;
When it is determined that the second acceleration is greater than the second threshold value, the step of designating, among the collected image data, image data captured during a predetermined storage period including the time as a storage target A method for storing vehicle travel data.

Images