JP7456166B2 - Charge amount control device, charge amount control method, and charge amount control program - Google Patents

Description

The present invention relates to a charge amount control device, a charge amount control method, and a charge amount control program.

Conventionally, rechargeable batteries and the like have been used as power sources for various devices, but in order to prevent deterioration of rechargeable batteries and extend their lifespan, a technique is known that maintains the amount of charge between 40% and 80% (for example, see Patent Document 1) ).

Japanese Patent Application Publication No. 2009-274677

However, if the charging capacity of the rechargeable battery was kept at 80%, there were situations in which the original charging capacity could not be utilized to the maximum.

The present invention was made in consideration of these circumstances, and its purpose is to provide a charge amount control device that maximizes the effect of the charge amount while also extending the life of the device.

In order to solve the above problems, a charge amount control device according to an aspect of the present invention includes a sign detection section that detects a sign of abnormality occurring in a vehicle, and a power supply control section that controls a charge amount of a power source. The power supply control unit normally controls the amount of charge of the power source to a predetermined suppressed charge amount that is lower than the maximum chargeable amount, and increases the amount of charge of the power source above the suppressed charge amount when a sign of abnormality occurrence is detected. .

Another aspect of the present invention is a method for controlling the charge amount. This method includes a process for detecting a sign of an abnormality occurring in a vehicle, and a process for controlling the charge amount of a power source. In the process for controlling the charge amount of the power source, the charge amount of the power source is normally controlled to a predetermined suppressed charge amount that is lower than the maximum chargeable amount, and when a sign of an abnormality is detected, the charge amount of the power source is controlled to be increased above the suppressed charge amount.

Note that arbitrary combinations of the above-mentioned constituent elements and mutual substitution of constituent elements and expressions of the present invention among methods, devices, systems, programs, etc. are also effective as aspects of the present invention.

According to the present invention, it is possible to provide a charge amount control device that maximizes the effect of charge amount and extends life.

FIG. 2 is a block diagram schematically showing the functional configuration of a drive recorder. FIG. 2 is a diagram schematically showing a circuit configuration of a drive recorder. 5 is a flowchart showing a power supply control process.

Embodiments of the present invention will be described below with reference to the drawings. The specific numerical values and the like shown in these embodiments are merely illustrative to facilitate understanding of the invention, and do not limit the invention unless otherwise specified. In this specification and the drawings, elements with substantially the same functions and configurations are given the same reference numerals to omit redundant explanation, and elements not directly related to the present invention are omitted from illustration. do. In the embodiment described below, a drive recorder is mainly exemplified as the charge amount control device, but the charge amount control device may be realized as a charge amount control device for electronic equipment other than the drive recorder. The charge amount control device implemented as a drive recorder is designed to prevent abnormalities such as damage to the vehicle and the drive recorder installed in the vehicle due to an accident, or disconnection or disconnection of the power supply cable to the drive recorder. When a sign is detected, the amount of charge in the backup power source is increased to prepare for the occurrence of the abnormality.

FIG. 1 is a block diagram schematically showing the functional configuration of the drive recorder 10. As shown in FIG. Each of the functional blocks shown in the figure can be realized in terms of hardware by elements and mechanical devices such as a computer's CPU and memory, and in terms of software by computer programs, etc., but here, we will explain how they work together. It is depicted as a functional block to be realized. Therefore, those skilled in the art will understand that these functional blocks can be realized in various ways by combining hardware and software.

The drive recorder 10 includes a surrounding information acquisition unit 18, a sign detection unit 30, a recording control unit 20, a temporary storage unit 22, a communication unit 24, an operation reception unit 26, a main power supply 50, a backup power supply 52, a power supply control unit 54, a display control unit 28, and an audio output unit 29. The surrounding information acquisition unit 18 acquires information about the surroundings of the vehicle. The surrounding information acquisition unit 18 includes an image acquisition unit 12, an audio acquisition unit 14, a vehicle information acquisition unit 16, and a traffic information acquisition unit 17. The image acquisition unit 12 may be configured as a part of the vehicle information acquisition unit 16, or the image acquisition unit 12 may be included in the vehicle information acquisition unit 16. The drive recorder 10 is mounted on a moving object such as a vehicle, a ship, or an aircraft. The communication unit 24 transmits and receives information to and from an external device through a wireless communication connection. The operation reception unit 26 accepts operation input from the user. The display control unit 28 controls the display of the captured image on the display device 49. The display device 49 is, for example, a monitor provided in the navigation device 11, but as a modified example, the drive recorder 10 may be configured to have the display device 49 built in. The audio output unit 29 controls audio output to a speaker 47 that outputs audio such as recorded audio and warning sounds. The speaker 47 is, for example, a speaker provided in the navigation device 11 or the vehicle, but as a modified example, the drive recorder 10 may be configured to have the speaker 47 built in. The connection between the drive recorder 10 and the navigation device 11 may be a wireless communication connection via the communication unit 24, or a wired communication connection such as a universal asynchronous receiver/transmitter (UART) or a universal serial bus (USB).

The image acquisition unit 12 acquires image data of the surroundings of the vehicle as information about the surroundings of the vehicle. Specifically, image data of moving images captured by the front camera 40 and rear camera 42 provided in the vehicle is acquired. The front camera 40 is configured to photograph the surroundings of the vehicle, particularly the front of the own vehicle. The rear camera 42 is configured to photograph the surroundings of the vehicle, particularly the rear of the own vehicle. The front camera 40 may be configured to photograph both the front of the own vehicle and the interior of the vehicle, or may be configured to photograph the entire front, side, and interior of the own vehicle, such as a single camera that can photograph the surrounding 360 degrees. It may be configured with a circumferential camera, or it may be configured with a plurality of cameras that take images of the front, rear, and sides. The front camera 40 and the rear camera 42 may be built into the drive recorder 10 or may be separate from the drive recorder 10. The rear camera 42 is a camera that also sends images of the rear to the navigation device 11, and serves as a camera for both the drive recorder 10 and the navigation device 11.

The image acquisition unit 12 may acquire images taken by the front camera 40 and the rear camera 42 as vehicle information regarding the running of the vehicle, and the image acquisition unit 12 may be considered as part of the vehicle information acquisition unit 16. The image acquisition unit 12 acquires images from the front camera 40 and also acquires images from the rear camera 42. The display control unit 28 causes the display device 49 to display an image from the front camera 40 while vehicle information indicating that the gear is set to a gear other than reverse, such as drive or parking, is acquired. An image from the rear camera 42 is displayed on the display device 49 while vehicle information indicating that the gear is in reverse is acquired.

The audio acquisition unit 14 acquires audio data acquired by a microphone 44 provided in the vehicle. The microphone 44 is configured to collect sounds from inside and outside the vehicle. The microphone 44 may be built into the drive recorder 10, may be separate from the drive recorder 10, or may be integrated with the front camera 40 or the rear camera 42. Alternatively, it may be built into the navigation device 11. When built into the navigation device 11, the microphone 44 is used for voice recognition operations of the navigation device 11. The audio acquisition unit 14 may acquire audio using the microphone 44 as vehicle information regarding the running of the vehicle, or may be considered as part of the vehicle information acquisition unit 16.

The vehicle information acquisition unit 16 acquires vehicle information regarding the running of the vehicle from an on-vehicle device 46 provided in the vehicle as information about the surroundings of the vehicle. Specific examples of the in-vehicle device 46 include a vehicle speed sensor, a steering angle sensor, an accelerator operation amount sensor, a brake operation amount sensor, an acceleration sensor, a gyro sensor, a radar sensor, a lidar (Light Detection and Ranging), and a position information sensor (for example, Examples include, but are not limited to, GNSS (Global Navigation Satellite System) and occupant seating sensors. The vehicle information acquisition unit 16 may acquire vehicle information from various control ECUs (Electronic Control Units) via an in-vehicle network such as a CAN (Controller Area Network), or may acquire vehicle information via the navigation device 11. You may. Alternatively, the position information may be acquired from a position information sensor built into the navigation device 11. The vehicle information acquisition unit 16 may acquire, via the communication unit 24, information detected by sensors such as an acceleration sensor, a gyro sensor, and a position information sensor built into a terminal such as a user's mobile phone. The vehicle information acquisition unit 16 may acquire information regarding the running of the vehicle from a sensor included in the drive recorder 10. For example, the drive recorder 10 may include a built-in sensor such as an acceleration sensor or a position information sensor. Note that the front camera 40, the rear camera 42, and the microphone 44 may be regarded as one of the in-vehicle devices, and the vehicle information acquisition section 16 may be configured to include the image acquisition section 12 and the audio acquisition section 14.

The vehicle information acquisition unit 16 collects, for example, information related to the state of the vehicle, information related to operations on the vehicle, information related to the speed of the vehicle, information related to the position of the vehicle, information related to obstacles around the vehicle, and information related to the operating state of the driving support function of the vehicle. Information etc. are acquired from the in-vehicle device 46. The various information acquired by the vehicle information acquisition unit 16 is detection information from a sensor other than a camera, unlike detection of objects around the vehicle through image analysis by a sign detection unit 30, which will be described later. The vehicle information acquisition unit 16 may acquire, for example, information indicating the open/closed states of doors and windows as information regarding the state of the vehicle. The vehicle information acquisition unit 16 may acquire, as information regarding operations on the vehicle, information indicating that an operation instructing opening/closing of a door or window has been performed, for example. The vehicle information acquisition unit 16 collects information regarding obstacles around the vehicle, such as whether there are other vehicles within a certain range around the vehicle, pedestrians, bicycles, fallen objects, or buildings in the lane in which the vehicle is traveling. Information indicating whether or not an obstacle such as an object exists may be acquired. The vehicle information acquisition unit 16 may acquire information indicating whether or not an occupant is present in the vehicle. The vehicle information acquisition unit 16 acquires information regarding on/off of an automatic driving function and a remote control function, and information regarding whether a specific driving support function is in operation, as the operating state of the driving support function of the vehicle. It's okay. Examples of driving support functions include, but are not limited to, adaptive cruise control (ACC) and lane keeping assist system (LKAS).

The traffic information acquisition unit 17 acquires traffic information as information about the surroundings of the vehicle via beacons installed on the road, broadcast waves, mobile phone communications, etc., via the communication unit 24. Alternatively, the traffic information acquisition unit 17 may acquire traffic information from the navigation device 11 or the vehicle via the communication unit 24.

The sign detection unit 30 detects a sign of abnormality occurring regarding the vehicle based on the information around the vehicle acquired by the surrounding information acquisition unit 18. The sign detection section 30 includes one or more of an image analysis section 32, a vehicle information analysis section 34, a voice analysis section 36, a traffic information analysis section 38, and the like. The image analysis unit 32 detects the approach of an object to the vehicle as a sign of the occurrence of an abnormality based on image analysis of the image data acquired by the image acquisition unit 12. The image analysis unit 32 stores in advance image recognition patterns for detecting various objects from images, and detects objects appearing in images using a predetermined image recognition algorithm based on the image recognition patterns. The image recognition pattern is defined, for example, by machine learning such as deep learning. The image analysis unit 32 uses image analysis to detect accidents such as vehicle collisions, contacts, rollovers, and falls, occurrence of troubles such as rough behavior or dangerous driving by drivers of surrounding vehicles, pedestrians, motorcycles, or obstacles. Detects the approach of Objects detected by the image analysis unit 32 include, for example, another vehicle rapidly approaching the host vehicle, people and animals, obstacles such as fallen objects and buildings on the road, and falling rocks. The sign detection unit 30 detects abnormality occurrence information acquired by the communication unit 24 through means such as road-to-vehicle communication and vehicle-to-vehicle communication, such as information on the occurrence of disasters such as earthquakes and lightning, and information on rough acts and dangerous driving that occur around the vehicle. A sign of abnormality occurrence may be detected based on trouble occurrence information.

The vehicle information analysis unit 34 detects signs of abnormality occurrence based on the vehicle information acquired by the vehicle information acquisition unit 16. The vehicle information analysis unit 34 recognizes sudden changes in vehicle behavior due to sudden starts, sudden stops, sudden turns, etc. from information on vehicle speed and acceleration, operation information such as accelerator, brake, and steering, for example. It may also detect signs of an abnormality such as an accident or pressing the accelerator and brake incorrectly. In other words, when the vehicle information analysis unit 34 recognizes vehicle information such as traveling speed or acceleration that is greater than a predetermined value, it detects a sign of abnormality occurrence. The vehicle information analysis unit 34 may detect a sign of abnormality occurrence by recognizing, from information such as a radar sensor of the vehicle, the approach of objects around the vehicle or deviation from the lane in which the vehicle is traveling. The vehicle information analysis unit 34 may also detect this as a sign of an abnormality when the operation reception unit 26 receives a press of a save start button provided on the drive recorder 10 or a voice instruction indicating the start of save. .

The audio analysis unit 36 detects signs of abnormality occurrence based on audio analysis of the audio data acquired by the audio acquisition unit 14. The audio analysis unit 36 uses audio analysis to detect signs of an abnormality such as an accident by recognizing, for example, brake sounds, horns, shouts, etc., and also recognizes, for example, sounds of vehicle collisions, contacts, rollovers, and falls. Detects the occurrence of abnormalities such as accidents. The audio analysis unit 36 may detect a sign of an abnormality such as an accident when the volume of the recognized brake sound, horn, scream, etc. is higher than a predetermined volume.

The traffic information analysis unit 38 detects a sign of abnormality based on the traffic information acquired by the traffic information acquisition unit 17, depending on whether the location has a relatively high possibility of abnormality occurring. For example, if the traffic information analysis unit 38 recognizes based on traffic information that there is a traffic jam or an accident ahead of the current location or the direction of travel, it determines that there is a possibility that an abnormality such as a collision will occur, and Detected as a sign of occurrence.

The sign detection section 30 may detect a sign of abnormality occurrence by combining the analysis results of various information by the image analysis section 32, the vehicle information analysis section 34, the voice analysis section 36, and the traffic information analysis section 38. In this case, the more analysis results that are combined, the more accurately the sign or possibility of abnormality occurrence can be detected. For example, if vehicle information detects that the brakes have been applied suddenly and a loud brake sound is detected based on audio information, it can be detected with high accuracy that a sudden deceleration has occurred due to sudden braking, which has a high risk of causing an accident. It can be detected as a sign of occurrence. When the sign detection unit 30 detects a sign of the occurrence of an abnormality, it transmits information indicating that the sign has been detected to the power supply control unit 54 . When the sign detection unit 30 detects a sign of the occurrence of an abnormality, it may divide the sign into levels depending on the type of abnormal situation, the degree of risk, and the probability of occurrence, and send the sign to the power supply control unit 54 in stages according to the level. good. For example, when an anomaly with a low level of danger is detected, information indicating that a sign of a "minor" level has been detected is initially transmitted, and later when an anomaly with a moderate level of danger is detected, information is sent that indicates that a warning sign of a "minor" level has been detected. If an abnormality with a high risk level is detected later, the level increases, such as by sending information indicating that a warning sign with a "major" level has been detected. Predictive information may be sent to the power supply control unit 54 every time.

The event detection section 27 detects various predetermined events (hereinafter referred to as " Detects the occurrence of a trigger event (referred to as a trigger event). A trigger event is a storage trigger event that is assumed to be a serious event such as a vehicle accident or trouble, and is a storage trigger event that, when it occurs or is detected, causes image data to be stored as overwrite-prohibited data. The event detection unit 27 detects, as a trigger event, the occurrence of an accident such as a vehicle collision, contact, rollover, or fall, or a trouble such as rough behavior or dangerous driving by a driver of a nearby vehicle. The event detection unit 27 detects the occurrence of an accident or trouble by image recognition or voice recognition based on a predetermined recognition pattern, for example from image data acquired by the front camera 40 and rear camera 42 and voice data acquired by the microphone 44. You may. The event detection unit 27 detects a trigger event by recognizing a sudden change in vehicle behavior due to a sudden start, sudden stop, sudden turn, etc., from information on vehicle speed and acceleration, operation information such as accelerator, brake, and steering, for example. may also be detected. The event detection unit 27 uses information such as image data from the front camera 40 and rear camera 42 and the radar sensor of the vehicle to detect the approach of objects around the vehicle, deviation from the lane in which the vehicle is running, etc. based on a predetermined recognition pattern. The occurrence of a trigger event may be detected by recognition. The event detection unit 27 may also detect this as the occurrence of a trigger event when the operation reception unit 26 receives a press of a save start button provided on the drive recorder 10 or a voice instruction indicating the start of save.

Note that the trigger event detected by the event detection section 27 may at least partially overlap the sign of abnormality occurrence detected by the sign detection section 30. However, since a trigger event is an opportunity to save image data, it is often detected at a time when there is a high possibility that a serious event has already occurred. On the other hand, the sign of abnormality detected by the sign detection unit 30 is only an opportunity to start charging the backup power source 52, which will be described later, and even if charging is started based on a misunderstanding, there is little inconvenience, so Another idea is to start charging if there is a possibility of an abnormality occurring. Therefore, the sign of an abnormality detected by the sign detection unit 30 is often at a pre-occurrence stage before a serious event has actually occurred, and even when the possibility of an abnormality occurring is not necessarily as high as the trigger event. Detect accurately. Preferably, the sign of abnormality occurrence detected by the sign detection section 30 is detected more frequently than the trigger event detected by the event detection section 27, or in advance of the trigger event. For example, when both the sign detection unit 30 and the event detection unit 27 detect a sign of abnormality occurrence based on the acceleration applied to the vehicle, the sign detection unit 30 uses a threshold value that is lower than the trigger event detected by the event detection unit 27. It is preferable to detect a sign of abnormality occurrence through comparison.

The recording control unit 20 records image data constantly captured by the front camera 40 or rear camera 42 and acquired by the image acquisition unit 12, audio data constantly collected by the microphone 44 and acquired by the audio acquisition unit 14, and vehicle information acquisition unit. Part or all of the vehicle information acquired by 16 is temporarily stored in temporary storage unit 22. The recording control unit 20 records the image data and audio data stored in the temporary storage unit 22 onto the recording medium 48 using a ring buffer method.

The temporary storage unit 22 may be a buffer memory configured with a nonvolatile memory such as a flash memory or a solid state drive (SSD), or a volatile memory such as a DRAM. The recording medium 48 is, for example, a memory card such as an SD card (registered trademark), is used by being inserted into a slot provided in the drive recorder 10, and is configured to be removable from the drive recorder 10. The recording medium 48 may be composed of an auxiliary storage device such as a solid state drive or a hard disk drive, or an auxiliary storage device built into the navigation device 11 may be used as such an auxiliary storage device. Note that the audio data stored in the temporary storage unit 22 and the audio data recorded on the recording medium 48 are stored or recorded in the form of moving image data combined with image data. However, depending on the mode selected by the user, the moving image data may be stored or recorded as silent image data that does not include audio data. Therefore, although not specifically explained, the concept of "image data" described below may or may not include audio data.

The image data to be stored in the temporary storage unit 22 may be stored as moving image data in a streaming format, such as MPEG2-TS, separated by a predetermined time period. The image data recorded on the recording medium 48 may be in the same format as the image data stored in the temporary storage unit 22, or may be in a different format, for example, a format with a higher compression ratio such as the MP4 format.

Since the recording control unit 20 records image data in the temporary storage unit 22 and the recording medium 48 using a ring buffer method, when the data recorded in the temporary storage unit 22 and the recording medium 48 reach their capacity, the oldest data is overwritten. be done. The recording control unit 20 temporarily records the image data in the temporary storage unit 22 and the recording medium 48 with an overwritable attribute.

When the occurrence of a trigger event is detected by the event detection unit 27, the recording control unit 20 controls the image data recorded on the recording medium 48 to be overwritten in a period that includes at least the detection timing of the trigger event. Set the save format. The overwritable and non-overwritable attributes may be set, for example, by writing in a predetermined flag included in the image data, or by writing the overwritable attribute in a management file such as an index that is independent of the image data. You may. When writing an attribute indicating whether or not overwriting is possible in the original image data itself, for example, information indicating the start position and end position of a storage target period in which overwriting is not allowed may be written in the original image data. In this case, when you later overwrite the part other than the part to be saved, that is, the part that can be overwritten, with other data, the other part is cut out and left as a result from the start position to the end position of the part to be saved. Overwrite. Alternatively, a specification may be adopted in which overwritable and non-overwritable parts are distinguished by cutting out the part to be saved from the original image data and saving it separately in the form of an independent file. If the portion to be saved spans multiple pieces of image data, a file may be saved that is cut out from each piece of image data and concatenated. When saving separately in the form of an independent file, it may be possible to distinguish between overwritable and non-overwritable data by recording it in a specific area, for example a specific folder, that is different from the area in which overwritable data is recorded. . Data set with an attribute that cannot be overwritten is maintained in an overwrite-inhibited state until it is deleted or changed to an overwrite-enabled attribute by an explicit operation by the user.

The display control unit 28 may visually notify the driver and fellow passengers that a sign of abnormality occurrence or a trigger event has been detected by displaying it on the display device 49 or the screen of the navigation device 11. The audio output unit 29 may audibly notify the driver and fellow passengers that a sign of abnormality occurrence or a trigger event has been detected. Although visual notification and auditory notification are illustrated as examples of notification modes in this embodiment, in a modified example, tactile notification, for example, a notification mode in which vibration is applied to the steering wheel to alert the driver, can be realized. It's okay.

The main power source 50 is, for example, an ACC power source (accessory power source) supplied with power from the vehicle. The backup power source 52 is an auxiliary power source configured with, for example, an electric double layer capacitor. The power supply control unit 54 monitors the voltages of the main power supply 50 and the backup power supply 52, and controls which of the main power supply 50 and the backup power supply 52 supplies power to each component of the drive recorder 10. Similar to general rechargeable batteries, electric double layer capacitors delay deterioration and extend their lifespan by suppressing the charge amount to a predetermined suppressed charge amount, for example 80%, which is lower than the maximum chargeable amount. can be achieved. Therefore, the power supply control unit 54 monitors the amount of charge of the backup power source 52 during normal times and controls the amount of charge to be maintained at 80%, which is the suppressed amount of charge. That is, if the amount of charge of the backup power source 52 is lower than 80%, the power supply control unit 54 charges the backup power source 52 to increase the amount of charge, and if the amount of charge of the backup power source 52 is higher than 80%, it stays at 80%. The standby power source 52 is kept in use until then. As a modification, if the amount of charge in the backup power source 52 is higher than 80%, the power source control unit 54 may cause the backup power source 52 to self-discharge until the amount of charge falls to 80%.

When detecting a sign of abnormality occurrence, the power supply control unit 54 increases the amount of charge of the backup power source 52 beyond the suppressed amount of charge. After increasing the charging amount beyond the suppressed charging amount, the power supply control unit 54 returns the charging amount to the suppressed charging amount when a predetermined state is reached in which no sign of abnormality occurrence is detected. Details regarding power supply and charging control will be described later.

FIG. 2 schematically shows an example of the circuit configuration of the drive recorder 10. In this figure, the circuit configuration related to power supply control will be mainly explained. The main power supply 50 outputs a DC voltage of 12V, for example. The first voltage converter 56 is a DC/DC converter that converts the voltage from the main power supply 50 into, for example, a 5V DC voltage. The power output from the first voltage converter 56 is supplied to a load 64 including a system circuit 66 and a power supply control section 54 via a selection circuit 62. The load 64 is each hardware configuration that is electrically driven in the drive recorder 10, and the system circuit 66 may be configured with a CPU, GPU, RAM, ROM, communication module, etc., and these configurations can be integrated into one chip. It may also be an SoC (System on Chip) configured to include the above. The system circuit 66 functions as the surrounding information acquisition section 18 and the omen detection section 30 in FIG. 28 and the audio output section 29.

The backup power source 52 is normally charged by the current from the charging circuit 60 until the amount of charge reaches 80%, which is the suppressed amount of charge. The backup power supply 52 may have a configuration in which a plurality of electric double layer capacitors are connected. For example, when two electric double layer capacitors each having an output voltage of 2.5V at the maximum charge amount are connected in series, The output voltage of the backup power source 52 at the maximum charging amount, that is, the maximum charging voltage, is 5.0V, and the output voltage at the suppressed charging amount of the electric double layer capacitor, which is 80% thereof, is 4.0V. The voltage from the backup power source 52 can be stepped up or down by the second voltage converter 58 and supplied to the load 64 via the selection circuit 62 . In a modification, a rechargeable battery such as a lithium ion battery or an alkaline storage battery may be used as the backup power source 52. The second voltage converter 58 is a DC/DC converter that converts the voltage from the backup power source 52 into, for example, a 5V DC voltage.

The power supply control unit 54 is a microcontroller that monitors the output voltage of the main power supply 50, the output voltage of the first voltage converter 56, and the charging voltage of the standby power supply 52, and controls the charging circuit 60 and the selection circuit 62. When the charge amount of the standby power supply 52 is less than 80%, which is the suppressed charge amount, the power supply control unit 54 controls the charging circuit 60 to charge the standby power supply 52 with power supplied from the charging circuit 60. When the charge amount of the standby power supply 52 reaches 80%, the power supply control unit 54 causes the standby power supply 52 to retain charge in that state, maintaining the 80% charge amount.

The power supply control unit 54 operates when the voltage output from the main power supply 50 becomes abnormal for some reason, that is, when the voltage from the main power supply 50 falls below a threshold voltage, for example, 6V, or when the voltage output from the first voltage converter 56 becomes abnormal. When the voltage from the main power supply 50 or the first voltage converter 56 falls below a threshold voltage, e.g. Switch to power supply from Although it depends on the load power amount of the load 64 and the capacity of the standby power source 52, as an example, when the charge amount of the standby power source 52 is 80%, which is the suppressed charge amount, the electric power is supplied from the standby power source 52 to the load 64 for about 5 seconds. Can be supplied. Under the same conditions, if the backup power source 52 is charged to the maximum charge amount of 100%, that is, to the maximum charging voltage, power can be supplied from the backup power source 52 to the load 64 for about 8 seconds. Although the power is supplied for a very short time, there is a large difference between 5 seconds and 8 seconds, and the image data can be saved or backed up during the few seconds until the load 64 is completely powered off. The longer the grace period is, even by 1 second, the more advantageous it will be to complete the backup. In particular, the main purpose of the drive recorder 10 is to reliably save image data in the event of a serious accident, and if the drive recorder 10 is damaged due to an accident and the image data cannot be saved. It is desirable to avoid this situation as much as possible. Therefore, when a sign of some abnormality occurrence is detected, the power supply control unit 54 increases the amount of charge of the backup power supply 52, and in the unlikely event that a serious accident occurs and the drive recorder 10 is damaged. Even in such cases, the reliability of processing can be increased by ensuring a grace period of even one second for processing such as saving image data.

When the power supply control unit 54 receives information indicating a sign of abnormality occurrence from the system circuit 66 (the sign detection unit 30), the power supply control unit 54 controls the backup power supply 52 from the main power supply 50 in order to increase the charge amount beyond the suppressed charge amount. The backup power supply 52 is charged by the power supply, that is, the charging circuit. The power supply control unit 54 receives information indicating a sign of abnormality occurrence from the CPU of the system circuit 66 via, for example, SPI (Serial Peripheral Interface) communication. The power supply control unit 54 stops charging when the charge amount of the backup power source 52 reaches the maximum charge amount of 100%, and maintains the charge amount of the backup power source 52 at 100%. The time required for the charge amount of the backup power source 52 to increase from the suppressed charge amount of 80% to 100% depends on the capacity of the backup power source 52 and the charging current value from the charging circuit 60 to the backup power source 52. As an example, it is about 2 seconds. When increasing the charging amount of the backup power source 52 to 100%, the power supply control unit 54 may temporarily increase the charging current value from the charging circuit 60 to the backup power source 52 to perform rapid charging. If a serious accident or the like occurs and the main power supply 50 is cut off while the charge amount of the backup power supply 52 is being increased or after the charge amount has been increased, the power supply control unit 54 switches the main power supply 50, that is, the first voltage conversion, as described above. The power supply from the converter 56 to the load 64 is switched to the power supply from the standby power supply 52, that is, the second voltage converter 58 to the load 64. In this way, by increasing the amount of charge in the backup power source 52 when a sign of abnormality is detected, it is possible to prevent the power supply from being lost from the main power source 50 to the load 64 due to a serious event such as a collision or accident. In preparation for the occurrence of such occurrence, it is possible to increase the reliability of image data storage from the preliminary stage.

If the predetermined increase release condition is met without power failure of the main power source 50, the power supply control unit 54 supplies power from the backup power source 52 to the load 64, so that the amount of charge becomes 80%, which is the suppressed amount of charge, again. The power of the standby power source 52 is consumed until the Here, the condition for canceling the increase is that a predetermined waiting time, for example 10 seconds, has elapsed since no sign of abnormality occurrence was detected. It is preferable that this standby time is at least longer than the time required to increase the amount of charge of the backup power source 52 from 80% to 100% (for example, 2 seconds).

If the power supply control unit 54 is designed to receive a sign of abnormality occurrence as well as information indicating the level of the sign, different controls may be performed depending on the level. For example, the power supply control unit 54 causes the charging circuit 60 to immediately start charging the backup power source 52 if the level of the sign is "high", and to start charging the backup power source 52 after one second if the level is "medium". Then, if the level is "low", different control is performed, such as starting charging of the backup power source 52 after 2 seconds. Thereby, unnecessary charging of the backup power source 52 can be reduced. For example, the power supply control unit 54 instructs the charging circuit 60 to set the maximum charge amount of the backup power source 52 to 100% if the level of the sign is "high", and to set the maximum charge amount of the backup power source 52 to 100% if the level of the sign is "medium". is set to 95%, and if the level is "low", different control is performed, such as setting the maximum charge amount of the backup power source 52 to 90%. Thereby, unnecessary charging of the backup power source 52 can be reduced. For example, the power supply control unit 54 sets the waiting time for the increase cancellation condition to 10 seconds if the level of the sign is "high", 9 seconds if the level is "medium", and 9 seconds if the level is "low". Different controls are used, such as setting the waiting time to 8 seconds. For example, if the level of the sign is "high", the charging of the backup power source 52 is set to the maximum rapid charge, if the level is "medium", the charging of the backup power source 52 is set to the medium quick charge, and if the level is "low" If so, a different control is performed, such as using the backup power source 52 for normal charging.

Note that if the range of targets recognized as a sign of an abnormality is too wide, or the conditions for the sign to be established are too relaxed, the abnormality will frequently be detected as a sign even though the probability of the abnormality occurring is low. As a result, the backup power source 52 may be repeatedly charged in excess of the suppressed charging amount. Moreover, if the standby time of the increase cancellation condition is made too long, the time during which the standby power source 52 is charged to the maximum charge amount also becomes longer. This may cause further deterioration of the backup power source 52. Therefore, the range of objects to be recognized as a sign of abnormality occurrence and the standby time of the increase canceling condition are set to appropriate values that can both maximize the effectiveness and extend the life of the backup power source 52 based on experimental verification. be done.

FIG. 3 is a flowchart showing the power supply control process. The power supply control unit 54 supplies power to the load 64 using the main power supply 50 or the first voltage converter 56 unless the output voltage of the main power supply 50 or the first voltage converter 56 is below the threshold value (N in S10). (S12), and when it is detected that the output voltage of the main power supply 50 or the first voltage converter 56 has decreased and has become below the threshold value (Y of S10), the power supply to the load 64 using the main power supply 50 is stopped. The power supply is switched to using the power supply 52, that is, the second voltage converter 58 (S22), and the process returns to the beginning of this flow.

In S12, while power is being supplied from the main power source 50 to the load 64, the sign detection unit 30 does not detect any sign of abnormality occurrence (N in S14), and the amount of charge in the backup power source 52 is 80%, which is the suppressed amount of charge. If it is less than that (Y in S16), the backup power source 52 is charged (S18), and the process returns to the beginning of this flow. If the charge amount of the backup power source 52 is not less than the suppressed charge amount of 80% (N in S16) but exceeds 80% (Y in S20), the backup power source 52 is used to reduce the charge amount to 80%. (S22) The charging amount is decreased, and the process returns to the beginning of this flow. If the charge amount of the backup power source 52 does not exceed 80%, which is the suppressed charge amount (N in S20), it is determined that the charge amount of the backup power source 52 is appropriate, and S22 is skipped and the process returns to the beginning of the flow. In S16 and S20 of this flow, the threshold value for determining the amount of charge of the backup power source 52 may have a range. For example, if the amount of charge of the backup power source 52 is 79% or more in S16 (N of S16), it may be determined that charging of the backup power source 52 is unnecessary, and in S20, the amount of charge of the backup power source 52 is 82% or more. If it does not exceed (N in S20), that is, it may be determined that the charge amount of the backup power source 52 is appropriate.

When the sign of an abnormality occurrence is detected by the sign detection unit 30 (Y in S14), if the amount of charge in the backup power source 52 is less than the maximum charge amount of 100% (Y in S24), the backup power source 52 is charged. (S18), and returns to the beginning of this flow. If the charge amount of the backup power source 52 is not less than the maximum charge amount of 100%, that is, if it is in the 100% state (N in S24), S18 is skipped and the process returns to the beginning of this flow. After that, if an abnormality actually occurs and the output voltage of the main power supply 50 or the first voltage converter 56 becomes below the threshold value (Y in S10), the power supply to the load 64 is switched to the backup power supply 52. (S22) If the battery is charged to the maximum charge amount of 100% at that point, power can be supplied to the load 64 for about 8 seconds. After a sign of an abnormality occurrence is detected, no abnormality actually occurs, and until a predetermined standby time has elapsed after the sign is no longer detected (Y in S14), the amount of charge of the backup power source 52 is at the maximum charge. As long as the amount is less than 100% (Y in S24), the backup power source 52 is charged (S18), but after the standby time has passed and the increase cancellation condition is satisfied (N in S14), the backup power source 52 is charged. Since the amount of charge is not less than the suppressed charge amount of 80% (N in S16) but exceeds 80% (Y in S20), the backup power source 52 is used until it reaches 80% (S22).

As described above in the embodiment, it is possible to both maximize the effect of the amount of charge of the backup power source 52 and extend its life. In particular, even in the unlikely event that a serious accident occurs and the drive recorder 10 is damaged, the grace period for processing such as saving image data can be increased by as much as one second to increase the reliability of processing. be able to. Further, even if no abnormality actually occurs, the reliability of preliminary power supply can be increased by detecting events that may be a sign of abnormality in advance. Further, by optimizing conditions such as the conditions under which the sign is satisfied and the standby time after the amount of charge is increased, wasteful charging can be reduced and deterioration of the standby power source 52 can be suppressed.

The present invention has been described above based on the embodiments. Those skilled in the art will understand that this embodiment is merely an example, and that various modifications can be made to the combinations of the constituent elements and processing processes, and that such modifications are also within the scope of the present invention. be.

10 drive recorder, 12 image acquisition unit, 14 audio acquisition unit, 16 vehicle information acquisition unit, 17 traffic information acquisition unit, 18 surrounding information acquisition unit, 30 omen detection unit, 32 image analysis unit, 34 vehicle information analysis unit, 36 audio analysis section, 38 traffic information analysis section, 50 main power supply, 52 standby power supply, 54 power supply control section.

Claims (7)

A charge amount control device installed in a drive recorder,
a surrounding information acquisition unit that obtains information around the vehicle including image data of the surroundings of the vehicle;
a sign detection unit that detects a sign of an abnormality occurring regarding the vehicle based on information around the vehicle ;
an event detection unit that detects the occurrence of a predetermined event regarding the vehicle;
a recording control unit that stores the image data when the event is detected;
a power supply control unit that controls the amount of charge of the power supply in the drive recorder ;
Equipped with
The sign detection unit is configured to detect the sign of the abnormality occurrence at a higher frequency than the frequency at which the event is detected by the event detection unit,
The power source control unit controls the amount of charge of the power source to be a predetermined suppressed charge amount lower than the maximum chargeable amount under normal conditions, and when the sign of the occurrence of the abnormality is detected, the amount of charge of the power source is controlled to be the suppressed charge amount. A charge amount control device characterized by increasing the amount of charge more than the amount of charge. The power supply control unit controls the amount of charge of a backup power source different from the main power source as the amount of charge of the power source,
2. The backup power source is used to store the image data according to the amount of charge controlled by the power source control unit when the output from the main power source becomes abnormal. The charge amount control device described in . The charge amount control device according to claim 1 or 2, wherein the sign detection unit detects an object approaching the vehicle as a sign of the occurrence of the abnormality based on image analysis of the image data. The surrounding information acquisition unit further obtains acceleration of the vehicle as information around the vehicle,
The event detection unit detects the occurrence of an event related to the vehicle based on the acceleration,
The sign detection unit detects the sign of the occurrence of the abnormality by comparing a threshold value lower than an acceleration threshold when the event is detected by the event detection unit and the acceleration of the vehicle acquired by the surrounding information acquisition unit. The charge amount control device according to claim 3, wherein the charge amount control device detects. The surrounding information acquisition unit obtains traffic information as information around the vehicle,
The amount of charge according to claim 1 or 2 , wherein the sign detection unit detects the sign of the occurrence of the abnormality based on the traffic information, depending on whether or not the place has a relatively high possibility of the occurrence of the abnormality. Control device. a process of acquiring information about the surroundings of the vehicle including image data taken of the surroundings of the vehicle;
a step of detecting a sign of abnormality regarding the vehicle based on information around the vehicle ;
detecting the occurrence of a predetermined event regarding the vehicle;
storing the image data if the event is detected;
A process of controlling the amount of charge of the power supply in the drive recorder ,
Equipped with
The process of detecting the sign is a process in which a detection standard is determined so that the sign of the abnormality occurrence is detected at a higher frequency than the frequency at which the event is detected,
In the process of controlling the charging amount of the power source, the charging amount of the power source is normally controlled to be a predetermined suppressed charging amount that is lower than the maximum chargeable amount, and when the sign of the occurrence of the abnormality is detected , the charging of the power source is controlled. A charging amount control method, characterized in that the charging amount is controlled to be increased more than the suppressed charging amount. A function to acquire information around the vehicle, including image data taken around the vehicle,
a function of detecting a sign of abnormality occurring regarding the vehicle based on information around the vehicle ;
a function of detecting the occurrence of a predetermined event regarding the vehicle;
a function of saving the image data when the event is detected;
A function to control the charging amount of the power supply in the drive recorder ,
realized by the computer in the drive recorder ,
The function of detecting the sign is configured to detect the sign of the occurrence of the abnormality at a higher frequency than the frequency at which the event is detected by the function of detecting the occurrence of the event,
The function of controlling the charging amount of the power source is to control the charging amount of the power source to a predetermined suppressed charging amount that is lower than the maximum chargeable amount under normal conditions, and to control the charging amount of the power source when a sign of the occurrence of an abnormality is detected. A charge amount control program characterized in that the amount of charge is increased more than the suppressed charge amount.

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