JP5650444B2 - Vehicle drive recorder and recorded information management method - Google Patents

Description

  The present invention relates to a vehicle drive recorder and a recorded information management method, and more particularly to a technique for eliminating the influence of malfunction.

  Vehicle drive recorders developed on the assumption that they are installed in automobiles are equipped with in-vehicle cameras, and in general, the situation of a short time zone including the time when an abnormality such as a traffic accident occurs is displayed as image information. Automatically record and save as. The presence or absence of an abnormality such as a traffic accident can be automatically identified by using an acceleration sensor or the like.

  In the case of a drive recorder equipped with a large-capacity storage device, images taken by the in-vehicle camera may be continuously recorded continuously. In this case, when an abnormality occurs, information on a mark (flag) indicating the occurrence of the abnormality is recorded together with the image.

  Such a drive recorder can reliably record the situation at the timing before and after that point as an image when a dangerous situation occurs while driving a car or when a traffic accident actually occurs. it can. Therefore, the information recorded by the drive recorder can be used as evidence when investigating the situation of an accident, or can be used for management and analysis of safe driving.

  By the way, for example, when the acceleration sensor detects an abnormally large acceleration (when the detected value exceeds a predetermined threshold), the following malfunction occurs in the case of a drive recorder that starts recording an image using this as a trigger: May occur. In other words, when a vehicle passes at a high speed on a road surface of a special part of the road, for example, a part where there is a joint of a bridge, or a part where there is a step or swell due to road surface repairs, there is no abnormality such as an accident. Nevertheless, a large acceleration is detected, and image recording is started using this as a trigger.

  Further, for example, in the drive recorder disclosed in Patent Document 1, a large acceleration acts in the left-right direction of the vehicle even when a normal steering wheel operation is performed on a sharp curve, and it may be erroneously detected that the vehicle is subjected to a large acceleration. It is said to be a problem.

  When a trigger is generated under conditions other than the above, unnecessary image data is recorded in large quantities in addition to important data. However, in the case of a general drive recorder, the capacity of the recording medium is often relatively small, so if the remaining recording capacity becomes insufficient, old data must be erased and overwritten with new data. . As a result, important image data in which accidents that have actually occurred in the past are overwritten and deleted by unnecessary new data.

  Even in the case of a drive recorder equipped with a large-capacity storage device and constantly recording captured image data, there are the following problems. That is, a flag is recorded on the image every time it occurs due to the above-mentioned trigger, but if a trigger occurs frequently even when an abnormality such as an accident does not occur, a large number of flags indicating unimportant parts Will be recorded. As a result, when searching for a specific location that represents the situation at the time of the accident from a large amount of recorded (long-term) image data, all the locations of the large number of recorded flags are checked. It is inevitable that work time and labor will be long.

  In Patent Document 1, as a countermeasure against malfunction, it is proposed to automatically adjust the relationship between the output of the sensor and the threshold value when the vehicle is traveling on a curve. That is, control is performed so that malfunctions are less likely to occur.

JP 2010-61681 A

  The technology of Patent Document 1 can be used as a countermeasure against malfunctions that occur while the vehicle is traveling on a curve, but the vehicle passes at a high speed through a place where there is a bridge joint or a step or undulation due to a road surface repair mark. It cannot be used as a countermeasure for malfunctions that occur in some cases. In addition, if the threshold value for identifying whether the acceleration is large or not is adjusted to a large value to reduce detection malfunctions, when an abnormality such as an accident actually occurs, a time delay occurs in the detection, or the detection cannot be performed. There is also a possibility.

  In any case, if triggers frequently occur due to malfunctions, there is a case where important image data cannot be recorded as described above. In the case of continuous recording, it is difficult to search for important image data from the recorded data.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to prevent important image data from being erased and to be important even when triggers are frequently generated due to malfunctions. An object of the present invention is to provide a vehicular drive recorder and a recorded information management method capable of easily specifying a location where image data exists.

In order to achieve the above-described object, a vehicle drive recorder according to the present invention is characterized by the following (1) to (4).
(1) at least data of the image captured by the vehicle-mounted camera starts recording on a recording medium in response to a predetermined event occurs or a predetermined flag at a timing always recorded to the event occurrence data of the image A vehicle drive recorder for recording,
A specific state monitoring unit that monitors the occurrence of a specific vehicle state that changes according to the driver's driving operation for at least a predetermined time after detecting the event occurrence;
When the specific vehicle state is not reached within the predetermined time after the occurrence of the event is detected, it indicates that the event occurrence is invalid with respect to the specific data recorded corresponding to the occurrence of the event. And a cancellation information adding unit for adding cancellation information.
(2) The vehicle drive recorder according to (1) above,
When there is not enough free space for data recording on a predetermined recording medium, data with the cancellation information added is deleted preferentially over other data. And a free space generation unit for generating a new free space.
(3) The vehicle drive recorder described in (2) above,
When there are a plurality of pieces of data to which the cancellation information is added, the free space generation unit deletes the data with the oldest recorded time from among the plurality of pieces of data.
(4) The vehicle drive recorder described in (2) above,
When there is only one piece of data to which the cancellation information is added, the free space generation unit preferentially deletes data with the oldest time recorded in the data to which the cancellation information is not added. about.

According to the vehicle drive recorder having the configuration (1), it is possible to easily distinguish whether or not an abnormality such as a traffic accident has occurred by monitoring the operation of the driver.
Further, according to the vehicle drive recorder having the configuration (2), it is possible to distinguish important data from other data with respect to data such as images recorded when the event occurs. That is, if an abnormality such as a traffic accident has actually occurred, the driver can perform a specific driving operation (for example, a hazard lamp starts blinking) in order to deal with the abnormal condition within a predetermined time after the occurrence of the event. Operation), a specific change appears in the vehicle state. On the other hand, if there is no abnormality such as when the vehicle passes through a place where there is a bridge joint or a step or undulation due to road surface repairs, there is no specific change in the vehicle state. Cancel information is added to the data to be processed. Therefore, it is possible to distinguish whether the importance level of the corresponding data is high depending on the presence / absence of cancellation information. If only the data to which the cancel information is added is targeted for deletion, it is possible to prevent important data from being deleted. In the case of continuous recording, the location of highly important data can be easily searched by selecting only data to which cancel information is not added as a search target.
Further, according to the vehicle drive recorder having the configuration of (3) above, even when the occurrence of the event is frequently detected due to malfunction, data with low importance, that is, data to which the cancellation information is added. Can be preferentially deleted to form a new free area in the data recording area. Therefore, highly important data can be stored over a long period of time, and new data can be recorded.
In addition, according to the vehicle drive recorder having the configuration (4), it is possible to reduce the possibility that data with high importance will be deleted by mistake. In other words, even if the data is regarded as less important data and the cancellation information is added, it is possible to capture the situation that is a precursor to an abnormality such as a traffic accident. There is sex. However, if the data is old in terms of time, the importance is considered low (relevance to the accident), so there is no problem even if it is deleted.

In order to achieve the above-described object, the recording information management method according to the present invention is characterized by the following (5).
(5) A recorded information management method for reading and managing information recorded on a predetermined recording medium by the vehicle drive recorder described in (1) above,
When searching for an area in which a predetermined flag indicating the event occurrence timing is recorded from the data recorded on the recording medium, the cancellation information is within a predetermined time from the flag timing of the corresponding time series data. Identify whether or not
When the cancellation information exists, the data of the corresponding flag is excluded from the search target.

  According to the recording information management method having the configuration (5), when searching for important data from a large amount of data recorded by the vehicular drive recorder that always performs the recording operation, the time required for the search is shortened. It becomes possible. That is, since the cancellation information is added in the vicinity of a flag indicating the timing of data with low importance, the importance level can be determined by setting only the position (timing) of the flag without the cancellation information as a search target. Can be searched easily.

  According to the vehicle drive recorder of the present invention, when recording data triggered by the occurrence of an event, important image data is erased even when the occurrence of the event is frequently detected due to malfunction. Can be prevented. Further, in the case of a vehicle drive recorder that always performs a recording operation, it becomes easy to identify a location where important image data exists. Further, according to the recorded information management method of the present invention, even when processing data containing a large amount of flags recorded due to malfunction, it is possible to easily search for highly important data.

  The present invention has been briefly described above. Further, details of the present invention will be further clarified by reading through the modes for carrying out the invention described below with reference to the accompanying drawings.

It is a block diagram which shows the structural example of the drive recorder for vehicles of embodiment. It is a flowchart which shows the main flow regarding operation | movement of the drive recorder for vehicles shown in FIG. It is a flowchart which shows the content of the trigger cancellation process shown in FIG. It is a flowchart which shows the modification of a trigger cancellation process. It is a flowchart which shows the process example in the case of reading and reproducing | regenerating the data recorded by the drive recorder for vehicles shown in FIG. (A)-(c) is a time chart which shows the operation example of the drive recorder for vehicles shown in FIG. (A)-(c) is a time chart which shows the operation example of the drive recorder for vehicles of a constant recording type.

  Specific embodiments of the vehicle drive recorder and the recording information management method of the present invention will be described below with reference to the drawings.

  An example of the configuration of the vehicle drive recorder of this embodiment is shown in FIG. As shown in FIG. 1, a drive recorder main body 10 includes a control unit (CPU (Central Processing Unit)) 11 and an acceleration (G) sensor 12. The control unit 11 is mainly composed of a control microcomputer. This microcomputer reads and executes a program prepared in advance, and realizes the function of a drive recorder described later.

  The acceleration sensor 12 is provided for detecting an abnormal state such as when a traffic accident occurs. That is, when the acceleration detected by the acceleration sensor 12 exceeds a predetermined threshold, it can be regarded as abnormal.

  However, in some cases, the presence or absence of an abnormality cannot be correctly identified by simply comparing the acceleration detected by the acceleration sensor 12 with a threshold value. For example, if a vehicle passes at a high speed on a road surface at a special place on the road, that is, a place where there is a joint of a bridge, or a place where there is a step or swell due to a road surface repair track, an abnormality such as an accident has occurred. In spite of the absence, a large acceleration is detected, which may be mistaken for an abnormality. In order to deal with this problem, the control unit 11 performs special control as described later.

  As shown in FIG. 1, the output of the in-vehicle camera 20 is connected to the drive recorder main body 10. The in-vehicle camera 20 is fixed on the vehicle and is positioned so that an image of a subject included in an area equivalent to a landscape that can be seen within the range of the field of view when the driver is driving, for example. The in-vehicle camera 20 continuously shoots a subject existing in a shootable region, for example, at a cycle of about 30 frames per second, and sequentially outputs the obtained image data.

  The recording medium 30 is connected to the drive recorder main body 10 for storing data such as images to be recorded. As a typical example of the recording medium 30, a memory card incorporating a nonvolatile semiconductor memory is assumed.

  In order to be able to identify various vehicle states, a vehicle speed signal 31, a brake signal 32, a right turn signal signal 33, a left turn signal signal 34, and a hazard lamp switch signal 35 are applied to inputs of the drive recorder body 10.

  The vehicle speed signal 31 is a pulsed electric signal that is output every time the vehicle wheel rotates a predetermined amount. The current vehicle speed can be calculated by measuring the cycle of the vehicle speed signal 31 and the like. The brake signal 32 is an electric signal indicating whether or not the vehicle brake pedal is depressed.

  The right turn signal 33 is an electric signal used for blinking the right turn indicator (turn signal lamp) for signaling the right turn or lane change of the vehicle, and the on / off state is switched according to the driver's predetermined switch operation. . Similarly, the left turn signal 34 is an electric signal used for blinking a left turn indicator for issuing a signal of turning left or changing lanes of the vehicle, and the on / off state is switched according to a predetermined switch operation by the driver.

  The hazard lamp switch signal 35 is an electric signal used for blinking the hazard lamp when a dangerous situation or accident occurs in the vehicle, and the on / off state is switched according to a predetermined switch operation by the driver.

  An outline (main flow) of the operation of the vehicle drive recorder shown in FIG. 1 is shown in FIG. The operation shown in FIG. 2 will be described below. When the ignition switch of the vehicle is turned on and the vehicle drive recorder is turned on, the microcomputer of the control unit 11 executes a predetermined initialization process, and then proceeds to the process of step S11.

  In step S11, a trigger indicating that an abnormal state to be recorded in the vehicle has occurred is monitored. Specifically, the acceleration (G value) detected by the acceleration sensor 12 is compared with a predetermined threshold value, and when the acceleration exceeds the threshold value, it is considered that a trigger has occurred.

  If the acceleration is within the threshold value, the process of step S11 is repeated, and if the acceleration exceeds the threshold value, the process proceeds to step S13 through step S12.

  In step S13, predetermined “trigger determination processing” and “recording processing” are started. In this “trigger determination process”, in order to confirm whether or not the detection of abnormal acceleration exceeding the threshold is a malfunction, a change in the state of the vehicle according to a predetermined driving operation is performed at least for a predetermined time (for example, 10 seconds) Monitor across. Specifically, the hazard lamp switch signal 35 is changed from OFF to ON, the left turn signal 34 is changed from OFF to ON, the brake signal 32 is changed from OFF to ON, and the vehicle speed is rapidly decreased. Monitor one.

  In other words, when an abnormal situation such as a traffic accident actually occurs, it is usually necessary to stop the vehicle by bringing it to the shoulder of the road immediately after that, and the driver flashes the hazard lamp or turns the blinker. Or by depressing the brake pedal to decelerate and stop the vehicle. In addition, when the vehicle collides with some obstacle, the vehicle speed may rapidly decrease even though the brake pedal is not depressed. Such a change in state is monitored by “trigger determination processing”.

  In addition, when “recording processing” is started in step S13, time-series data of moving images obtained by photographing by the in-vehicle camera 20 is sequentially recorded on the recording medium 30 until a predetermined time (for example, 10 seconds) elapses thereafter. The In addition, data of an image taken during a predetermined time (for example, 10 seconds) before the trigger is generated is recorded on the recording medium 30.

  Actually, the drive recorder main body 10 always records image data captured within a predetermined time (for example, 10 seconds) in the internal buffer memory regardless of the start of the “recording process” accompanying the trigger generation. Yes. For example, as in the image data T1, T2, and T3 shown in FIG. 6A, the latest image data within a predetermined time is always stored in the buffer memory at each time point. When a trigger occurs, image data taken before that time is taken out from the buffer memory, and further transferred to the recording medium 30 in combination with image data taken after the trigger occurs, so that a predetermined time before and after the occurrence of the trigger. Thus, data can be recorded on the recording medium 30.

  The recording area on the recording medium 30 is divided into a plurality of independent folders, and is managed for each folder. Each time a trigger is generated in step S12, one folder on the recording medium 30 is allocated, and data is written into the corresponding folder by the “recording process”. Information indicating the date and time when the folder is created or the date and time when the folder is assigned is also added to each folder and data to be written therein.

  When a predetermined change (for example, change of the hazard lamp switch signal 35 from OFF to ON) appears in the vehicle state within a predetermined time (for example, 10 seconds) after starting the “trigger determination process” in step S13. Return to the process of step S11, and if there is no change within a predetermined time, the process proceeds to step S15 through step S14.

  In step S15, a “trigger cancellation process” is executed to cancel the trigger generation result detected in step S12. That is, if a trigger frequently occurs due to malfunction even though no abnormality such as an accident has occurred, a large amount of unimportant useless data is recorded on the recording medium 30, and the important data recording the accident is wasted. May be overwritten by incorrect data. In order to prevent this, “trigger cancellation processing” is executed.

  For example, if a vehicle passes at a high speed on a road surface at a special place on the road, that is, a place where there is a joint of a bridge, or a place where there is a step or swell due to a road surface repair track, an abnormality such as an accident has occurred. Despite the absence, large accelerations can be detected and triggers can occur frequently.

  Details of the “trigger cancellation process” in step S15 are shown in FIG. That is, if a predetermined change does not appear in the state of the vehicle within a predetermined time after starting the “trigger determination process” in step S13 of FIG. 2, the process proceeds to step S21 of FIG.

  In step S21, the folder in which the data is recorded last is specified among the plurality of folders on the recording medium 30, and predetermined “cancellation information” is added to the corresponding folder. In other words, “cancellation information” is added as information representing the attribute to a specific folder on the recording medium 30 that is an area in which data recorded in response to the last generated trigger is stored. Whether or not each folder is applicable can be identified by comparing the folder creation date and time, the folder allocation date and time, the data creation date and time, etc. with each other. Note that “cancellation information” is not added to each folder in the initial state.

  In this example, it is assumed that “cancellation information” is added to a folder that is an area for holding the corresponding image data. However, “cancellation information” is used as information indicating the attribute of the corresponding image data itself. You may control to add.

  In step S22, the capacity (free capacity) of the remaining recording area existing on the recording medium 30 is detected, and it is identified whether or not this capacity is sufficient. Specifically, the length of time for which an image is recorded for one trigger is constant, and the amount of information recorded during this time is also approximately constant. It is identified whether or not a certain amount of free space is secured for recording information. If the free space is sufficient, the process returns to step S11, and if it is insufficient, the process proceeds to step S23.

  In step S23, a search is made for a number of folders to which the “cancel information” is added from among a large number of folders existing on the recording medium 30, and the number of folders to which the “cancel information” is added is identified. If the number of corresponding folders is 2 or more, the process proceeds to step S24, and if the number of corresponding folders is 1 or 0, the process proceeds to step S25.

  In step S24, a specific folder holding data with the oldest date and time is searched from a plurality of folders to which “cancellation information” is added, and the corresponding one folder and all the data in the folder are deleted. . By this process, a new recording area, that is, a free space necessary for recording information for a predetermined time when the next trigger occurs is secured on the recording medium 30.

  Data in a folder to which “cancellation information” is added may not necessarily be less important data. However, when there are multiple folders with “cancellation information” added, there is a high possibility that triggers have occurred frequently. For folders with relatively old data recording dates and times, Since it is considered that the degree of importance is low, this is preferentially erased to secure a new area.

  In step S25, a specific folder holding data with the oldest date and time is searched from a plurality of folders to which “cancellation information” is not added, and the corresponding one folder and all the data in the folder are deleted. . By this process, a new recording area, that is, a free space necessary for recording information for a predetermined time when the next trigger occurs is secured on the recording medium 30.

  When there is only one folder to which “cancellation information” is added, there is a possibility that triggers are not frequently generated, so the importance of data in the corresponding folder may be high. Accordingly, considering the data recording date and time rather than the presence / absence of “cancellation information”, data in a relatively old folder is preferentially erased to secure a new area.

  Therefore, for example, as in “Case 1” shown in FIG. 6B, a trigger is generated at time t1, and the hazard lamp switch signal 35 is turned on at time t2 before a predetermined time elapses (start of lamp blinking). Then, the process returns from step S14 in FIG. 2 to step S11, and the “trigger cancellation process” in step S15 is not executed. Accordingly, in this case, no cancellation information is added to the folder holding the corresponding image data.

  On the other hand, when a trigger is generated at time t1 as in “Case 2” shown in FIG. 6C, and the vehicle state does not change even at time t3 after a predetermined time has elapsed, FIG. The process proceeds from step S14 to step S15, and the “trigger cancellation process” is executed. Accordingly, in this case, cancellation information is added to the folder holding the corresponding image data.

  The vehicle drive recorder described above performs an operation of recording data such as an image for a certain period of time every time a trigger occurs (trigger recording type). That is, since the recording capacity of the recording medium 30 for storing the data is small, it is impossible to record all the image data for a long time, and the image is taken at an important time zone related to an abnormality such as a traffic accident. Record data only. However, for example, when a large-capacity recording device such as a hard disk device is provided, the limitation on the recording capacity is small, so that not only the specific time zone in which the trigger occurs but also image data can be recorded constantly. it can.

  When image data is always recorded (always recording type), the operation of the vehicle drive recorder shown in FIG. 2 is changed as follows. In FIG. 2, when the trigger is generated, the “recording process” is started in step S13. However, in the case of constant recording, the same “recording process” is performed immediately after the vehicle drive recorder is turned on. Is started and the “recording process” is continued unless a special operation is performed to turn off the power.

  In order to facilitate the management of the recorded image data, the image data is stored in the recording medium 30 as a plurality of independent data files by dividing the long-time image data at fixed time intervals (for example, every 10 seconds). It may be recorded.

  Even in the case of continuous recording, in order to facilitate data analysis, it is necessary to record time-series data on the recording medium 30 so that the timing at which a trigger occurs (an abnormality is detected) can be known. . Therefore, at the timing of executing step S13 in FIG. 2, flag information indicating the occurrence of the trigger is added as attribute information to the image data captured at the corresponding time.

  For example, as in the example shown in FIG. 7A, when trigger 1 is generated at time t1, trigger 2 is generated at time t2, and trigger 3 is generated at time t3, the trigger is applied to the image data at time t1. Information 1 is recorded as a flag, trigger information 2 is recorded as a flag in the image data at time t2, and trigger information 3 is recorded as a flag in the image data at time t3.

  In the case of continuous recording, the processing shown in FIG. 4 is performed in step S15 of FIG. That is, if a predetermined change does not appear in the state of the vehicle within a predetermined time after starting the “trigger determination process” in step S13 of FIG. 2, the process proceeds to step S31 of FIG. Predetermined “cancellation information” is added to the time series data.

  Therefore, for example, as in “Case 1” shown in FIG. 7B, a trigger is generated at time t1, and the hazard lamp switch signal 35 is turned on at time t2 before a predetermined time elapses (start of lamp blinking). Then, the process returns from step S14 in FIG. 2 to step S11, and the “trigger cancellation process” in step S15 is not executed. Accordingly, in this case, cancel information is not added to the image data at the corresponding time.

  On the other hand, when a trigger occurs at time t1 as in “Case 2” shown in FIG. 7C, and the vehicle state does not change even at time t3 after a predetermined time has elapsed, FIG. The process proceeds from step S14 to step S15, and the “trigger cancellation process” is executed. Accordingly, in this case, cancellation information is added to the image data at the corresponding time.

  As for the cancellation information to be added, if the trigger information in correspondence can be found immediately, the cancellation information may be written to overwrite this trigger information, or the corresponding trigger information is deleted instead of writing the cancellation information. You may do it. Further, cancellation information may be added to the image data at the time point (t3) when it is recognized that there is no change in the state of the vehicle even after a predetermined time has elapsed.

  By the way, when the user reads out data recorded on the recording medium 30 to reproduce and analyze an image in a target time zone, if the vehicle drive recorder is a “trigger recording type”, the entire data Since the amount is small, it is easy to find the target image. However, when the vehicular drive recorder is an “always recording type”, the total amount of data recorded may be enormous, so it takes time to find an image in the target time zone. In particular, when triggers occur frequently, a lot of trigger information is recorded, so it is not easy to find an image in the target time zone even if only the image data in the time zone where the trigger information exists is extracted. Absent.

  Therefore, when the data recorded on the recording medium 30 is read by the “always recording type” vehicle drive recorder and the user tries to reproduce and analyze the image in the target time zone, the procedure as shown in FIG. The recorded information management method is used. The processing procedure shown in FIG. 5 can be automatically executed by an image analysis computer (general personal computer or the like).

  In step S41, data such as an image recorded from the recording medium 30 is read, and the content of the image is reproduced from the first time and displayed on the screen. If a predetermined search instruction is received by the user's input operation, the process proceeds to the next step S42.

  In step S42, the image data recorded on the recording medium 30 is searched from the beginning in time series order to find the position where the flag (trigger information) indicating the occurrence of the trigger exists. If this trigger information is found, the presence / absence of “cancel information” associated therewith is identified. If “cancel information” exists, the process proceeds to step S43, and if not, the process proceeds to step S44.

  As to whether “cancellation information” associated with the trigger information exists, whether or not “cancellation information” exists in time-series data within a predetermined time (for example, within 10 seconds) from the recording position of the trigger information. What is necessary is just to identify. When time-series image data is divided into predetermined time intervals and exists as independent data files, it is identified whether or not “cancellation information” exists as an attribute in the data file including the corresponding trigger information. That's fine.

  In step S43, since “cancellation information” is associated with the retrieved trigger information, this trigger information is regarded as invalid and its display is omitted. When the search is continuously performed, the image data in the time zone of the corresponding trigger information is excluded from the search target, and the search for the next trigger information is immediately started.

  In step S44, since there is no “cancellation information” in the retrieved trigger information, this trigger information is regarded as valid, and an image in the corresponding time zone is reproduced and displayed on the screen together with this trigger information.

  As described above, when a predetermined event occurrence such as detection of an abnormally large acceleration is used as a trigger, the trigger may frequently occur. In other words, when a vehicle passes at a high speed on a road surface at a special place on the road, that is, a place where there is a joint of a bridge, or a place where there is a step or a swell due to a road surface repair mark, there is no abnormality such as an accident. Nevertheless, a large acceleration is detected.

  Therefore, in the case of a “trigger recording type” vehicle drive recorder that starts recording of image data and triggers recording for a certain period of time when triggered by such a trigger, a large number of low-use-value image data is recorded, and the recording medium There is a possibility that highly important image data may disappear due to the limitation of 30 recording capacity. However, by performing the processes shown in FIGS. 2 and 3, when the free area on the recording medium 30 is insufficient, only the image data with low importance is automatically deleted preferentially. Accordingly, it is possible to prevent the image data having high importance from being lost.

  In addition, in the case of an “always-recording type” vehicle drive recorder, a large number of flags indicating the occurrence of a trigger may be recorded in long-time image data. It may be difficult or time consuming to search for a location. However, when the processes shown in FIGS. 2 and 4 are performed, since “cancellation information” is added to the trigger information (flag) of the image position with low importance, the position of the important image data Can be easily searched. That is, by using the recording information management method of the procedure shown in FIG. 5, the image data in the time zone of the trigger information to which “cancel information” is added is excluded from the search target. The number decreases, and the position of the target image data can be found in a short time.

  It should be noted that if it is attempted to identify whether or not the trigger is due to erroneous detection at the time when the occurrence of the trigger is detected (when shifting from step S12 to S13), the process takes several seconds, so the data There is a high possibility that a large time lag will occur between the trigger timing at the time of recording and the actual abnormality occurrence timing. However, when performing recording of data triggered by a trigger as shown in FIGS. 2 to 4 or adding “cancellation information” for invalidating the trigger after recording the trigger information, There is no deviation in trigger timing.

  As described above, in the “trigger determination process” in step S13 of FIG. 2, the hazard lamp switch signal 35 is turned from off to on in order to confirm whether or not the detection of abnormal acceleration exceeding the threshold is a malfunction. At least one of a change in the left blinker signal 34 from off to on, a change in the brake signal 32 from off to on, and a sudden decrease in vehicle speed. In other words, if there is a change in the state of the vehicle according to a predetermined driving operation within a predetermined time after the occurrence of the trigger, it is regarded as a correct trigger due to the occurrence of an abnormality such as an accident. Is considered to be a trigger.

That is, the determination conditions in steps S13 and S14 in FIG. 2 are conditions for distinguishing whether or not the trigger is correct due to the occurrence of an abnormality such as an accident. Therefore, for example, at least one of the following various conditions is used. It is conceivable to use one.
1. The hazard lamp switch signal 35 has changed from off to on.
2. The left turn signal 34 has changed from off to on.
3. The brake signal 32 changed from OFF to ON, and the ON state continued for a predetermined time (detection of sudden deceleration).
4). The brake signal 32 is in an off state, and the vehicle speed has decreased to a predetermined value within a predetermined time (detection of an abnormal speed decrease due to a collision or the like).
5. The left turn signal 34 changed from off to on and the on state continued for a predetermined time or more (distinguishment from simple lane change).

  As described above, the present invention can be assumed to be applied to the aforementioned “trigger recording type” vehicle drive recorder and “always recording type” vehicle drive recorder. When triggers occur frequently in response to changes in the road surface on which the vehicle is traveling, even though no abnormality has occurred, data is automatically distinguished from important triggers and non-critical triggers. Can be recorded.

  Therefore, in the case of a “trigger recording type” vehicle drive recorder, it is possible to prevent important image data recorded in the event of an accident from being erased. In the case of an “always recording type” vehicle drive recorder, the trigger information indicating the position of important image data recorded in the event of an accident, etc. is distinguished from other trigger information by “cancellation information”. it can. Therefore, when the data recorded on the recording medium is read and analyzed by the vehicle drive recorder, the position of the target image data can be retrieved in a short time by implementing the recording information management method of the present invention.

10 Drive recorder body 11 Control unit (CPU)
12 Acceleration sensor 20 Car-mounted camera 30 Recording medium 31 Vehicle speed signal 32 Brake signal 33 Right turn signal 34 Left turn signal 35 Hazard lamp switch signal

Claims (5)

Vehicle that starts recording at least an image data taken by a vehicle-mounted camera on a recording medium in response to occurrence of a predetermined event, or records the image data constantly and records a predetermined flag at the event occurrence timing Drive recorder for
A specific state monitoring unit that monitors the occurrence of a specific vehicle state that changes according to the driver's driving operation for at least a predetermined time after detecting the event occurrence;
When the specific vehicle state is not reached within the predetermined time after the occurrence of the event is detected, it indicates that the event occurrence is invalid with respect to the specific data recorded corresponding to the occurrence of the event. A vehicle drive recorder comprising: a cancellation information adding unit that adds cancellation information. When there is not enough free space for data recording on a predetermined recording medium, data with the cancellation information added is deleted preferentially over other data. The vehicle drive recorder according to claim 1, further comprising: a free space generation unit that generates a new free space. In the case where there are a plurality of pieces of data to which the cancellation information is added, the free space generation unit deletes data having an older recorded time from the plurality of pieces of data more preferentially. The vehicle drive recorder according to claim 2. When there is only one piece of data to which the cancellation information is added, the free space generation unit preferentially deletes data with the oldest time recorded in the data to which the cancellation information is not added. The vehicle drive recorder according to claim 2. A recorded information management method for reading and managing information recorded on a predetermined recording medium by the vehicle drive recorder according to claim 1,
When searching for an area in which a predetermined flag indicating the event occurrence timing is recorded from the data recorded on the recording medium, the cancellation information is within a predetermined time from the flag timing of the corresponding time series data. Identify whether or not
When the cancellation information exists, the data of the corresponding flag is excluded from the search target.

Images