Data storage device, vehicle, data storage system, and storage medium

Abstract

Provided is a technique capable of adjusting the amount of stored vehicle data in accordance with the environment around a vehicle. A data storage device is provided with: a control unit that, in response to the detection of a predetermined vehicle condition, stores vehicle data corresponding to the vehicle condition in a storage device; and an acquisition unit that acquires environmental information about the surroundings of the vehicle, and the control unit determines the sampling frequency of the vehicle data stored in the storage device on the basis of the environmental information acquired by the acquisition unit and a pre-acquired relationship between the environmental information and the sampling frequency of the vehicle data. The vehicle data sampled at the determined sampling frequency is stored in a storage device.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a data storage device, a vehicle, a data storage system, and a storage medium. BACKGROUND

[0002] Patent Literature 1 discloses a data storage device for a vehicle. The device stores vehicle data in a nonvolatile ring buffer in response to a case where a predetermined vehicle condition, such as acceleration / deceleration / lateral acceleration becoming a predetermined value or more, is detected. The vehicle data includes a detection value of an on-vehicle sensor, and is used for a vehicle manufacturer or the like to analyze a prescribed event afterward.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] [Patent Literature 1] Japanese Patent Application Publication No. 2013-073610 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The event to be analyzed includes an event related to safety of traffic. The event related to safety of traffic is abnormality of an on-vehicle system or excessive approach to a surrounding object, or the like. It is assumed that the probability of occurrence of such an event increases depending on an environment in which a vehicle travels. However, the device described in Patent Literature 1 stores vehicle data regardless of the environment in which the vehicle travels, and thus there is a possibility that sufficient amount of data cannot be stored when the event to be analyzed occurs. The present disclosure provides a technology capable of adjusting an amount of vehicle data to be stored in accordance with an environment of a surrounding of a vehicle.

[0008] MEANS FOR SOLVING THE PROBLEMS

[0009] A data storage device according to one embodiment of the present disclosure includes a control section that stores vehicle data corresponding to a vehicle condition in a storage device in response to a case where the predetermined vehicle condition is detected, and an acquisition section that acquires environment information of a surrounding of the vehicle, the control section determining a sampling frequency of the vehicle data to be stored in the storage device based on the environment information acquired by the acquisition section and a previously acquired relationship between the environment information and the sampling frequency of the vehicle data, and storing the vehicle data sampled at the determined sampling frequency in the storage device.

[0010] In the data storage device, environment information of a periphery of the vehicle is acquired. Then, based on the acquired environment information and a previously acquired relationship between the environment information and a sampling frequency, the sampling frequency of the vehicle data to be stored in the storage device is decided. Then, in response to a case where a predetermined vehicle condition is detected, the vehicle data sampled at the decided sampling frequency is stored in the storage device. Thus, the data storage device can adjust the data amount of the stored vehicle data according to the environment of the periphery of the vehicle 2, because it can change the sampling frequency of the vehicle data according to the environment information.

[0011] In one embodiment, the environment information can include at least one of rainfall amount, snowfall amount, sunshine amount, intensity of backlight, and road freezing degree, and the previously acquired relationship between the environment information and the sampling frequency of the vehicle data can be a relationship in which the larger the environment information, the larger the sampling frequency of the vehicle data. In this case, the data storage device can increase the data amount of the stored vehicle data more in a condition where the environment that hinders the running and driving of the vehicle, i.e., the possibility that the driver encounters an unsafe event, is high. Therefore, the data storage device can improve the event analysis capability compared with a device that stores vehicle data uniformly.

[0012] In one embodiment, the environment information can include at least one of rainfall amount, snowfall amount, sunshine amount, intensity of backlight, and road freezing degree, and the previously acquired relationship between the environment information and the sampling frequency of the vehicle data can be a relationship in which the sampling frequency of the vehicle data is made larger in stages according to the size of the environment information. In this case, the data storage device can increase the data amount of the stored vehicle data more in a condition where the environment that hinders the running and driving of the vehicle, i.e., the possibility that the driver encounters an unsafe event, is high. Therefore, the data storage device can improve the event analysis capability compared with a device that acquires vehicle data uniformly.

[0013] In one embodiment, the control section can also set an upper limit value to the sampling frequency of the vehicle data. If the data amount of the vehicle data is increased according to the environment information, the capacity of the storage device can be insufficient. The data storage device can avoid the capacity of the storage device being squeezed beyond the expectation by setting an upper limit value to the sampling frequency.

[0014] In one embodiment, the vehicle data can include image data, and the control section can decide the number of pixels of the image data to be stored in the storage device based on the environment information acquired by the acquisition section and a previously acquired relationship between the environment information and the number of pixels of the image data, and store the image data converted to the decided number of pixels in the storage device. The data storage device can adjust the data amount of the stored image data according to the environment of the periphery of the vehicle, because it can change the number of pixels of the image data according to the environment information.

[0015] In one embodiment, the control section can set the number of storable times within a predetermined period for each category of vehicle conditions, in response to detecting the situation of the vehicle condition, store the vehicle data in the storage device when the number of stored times related to the vehicle condition is less than the number of storable times, not store the vehicle data in the storage device when the number of stored times related to the vehicle condition is equal to or more than the number of storable times, acquire an actual value of the number of stored times within the predetermined period, and correct the number of storable times in a manner close to the actual value. The data storage device can avoid the capacity of the storage device being squeezed beyond expectation because the number of stored vehicle data for post-analysis can be corrected based on the actual value.

[0016] Another aspect of the present disclosure relates to a vehicle including a control section that stores vehicle data corresponding to a vehicle condition in a storage device in response to detecting the situation of the vehicle condition, and an acquisition section that acquires environmental information around the vehicle. The control section determines a sampling frequency of the vehicle data stored in the storage device based on the environmental information acquired by the acquisition section and a previously acquired relationship between the environmental information and the sampling frequency of the vehicle data, and stores the vehicle data sampled at the determined sampling frequency in the storage device. The vehicle achieves the same effects as the above-described data storage device.

[0017] Another aspect of the present disclosure relates to a data storage system including a control section that stores vehicle data corresponding to a vehicle condition in a storage device in response to detecting the situation of the vehicle condition, and an acquisition section that acquires environmental information around the vehicle. The control section determines a sampling frequency of the vehicle data stored in the storage device based on the environmental information acquired by the acquisition section and a previously acquired relationship between the environmental information and the sampling frequency of the vehicle data, and stores the vehicle data sampled at the determined sampling frequency in the storage device. The data storage system achieves the same effects as the above-described data storage device.

[0018] Another aspect of the present disclosure relates to a program executed by a control section in a data storage device including the control section that stores vehicle data corresponding to a vehicle condition in a storage device in response to detecting the situation of the vehicle condition, and an acquisition section that acquires environmental information around the vehicle. The program causes the control section to function to determine a sampling frequency of the vehicle data stored in the storage device based on the environmental information acquired by the acquisition section and a previously acquired relationship between the environmental information and the sampling frequency of the vehicle data, and to store the vehicle data sampled at the determined sampling frequency in the storage device. The program achieves the same effects as the above-described data storage device.

[0019] Effects of Invention

[0020] According to the present disclosure, there is provided a technique capable of adjusting the data volume of stored vehicle data in accordance with the environment of the surroundings of a vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a block diagram showing an example of the configuration of a vehicle provided in a data storage device according to an embodiment.

[0022] Figure 2 is a graph showing the relationship between the sampling frequency of vehicle data and the estimated one-hour rainfall amount, and the relationship between the assumed occurrence number of a prescribed event and the estimated one-hour rainfall amount.

[0023] Figure 3 (A) of FIG. 1 is a graph showing the relationship between the data volume of data taken at a first sampling frequency and the time of day, Figure 3 (B) of FIG. 1 is a graph showing the relationship between the data volume of data taken at a second sampling frequency greater than the first sampling frequency and the time of day.

[0024] Figure 4 (A) of FIG. 2 is a flowchart showing the action of a data storage device deciding the sampling frequency of vehicle data, Figure 4 (B) of FIG. 2 is a flowchart showing the action of a data storage device storing vehicle data.

[0025] Figure 5 is a graph showing the relationship between the number of pixels of image data and the estimated one-hour rainfall amount, and the relationship between the assumed occurrence number of a prescribed event and the estimated one-hour rainfall amount.

[0026] Figure 6 is a table showing the relationship between the category of a vehicle condition and the number of times of saving.

[0027] Figure 7 is a flowchart showing the action of changing the number of times of saving.

[0028] Figure 8 is a block diagram showing an example of the configuration of a data storage system according to an embodiment. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are marked with the same reference numerals, and overlapping description is omitted.

[0030] [Configuration of Vehicle]

[0031] Figure 1 is a block diagram showing an example of the configuration of a vehicle provided in a data storage device according to an embodiment. As shown in FIG. 7, the vehicle 1 includes a vehicle data storage device 10, a vehicle data acquisition device 20, a vehicle data transmission device 30, and a vehicle data reception device 40. Figure 1As shown, the data storage device 1 is mounted on the vehicle 2 as an example. The data storage device 1 is a device that stores data such as detection values of on-vehicle sensors in a recording medium in order to enable a vehicle manufacturer or the like to analyze a prescribed event afterward. The vehicle 2 can be a vehicle driven by a driver or an autonomous vehicle.

[0032] The vehicle 2 is provided with an external sensor 3, an internal sensor 4, an environmental sensor 5, a vehicle system 6, and a storage device 7.

[0033] The external sensor 3 is a detection device that detects a surrounding condition of the vehicle 2. The surrounding condition includes other vehicles, pedestrians, obstacles, a division line provided on a road, an illumination state of a signal light, and the like around the vehicle 2. The external sensor 3 includes at least one of a camera and a radar sensor. The camera is an imaging device that images an external condition of the vehicle 2. The camera is provided, for example, on the inner side of a front windshield of the vehicle 2, and images a front of the vehicle 2. The camera can also be provided in a plurality of ways that image side and rear of the vehicle 2. The radar sensor is a detection device that detects an object around the vehicle 2 using an electric wave such as a millimeter wave or light. The radar sensor includes, for example, a millimeter wave radar or a laser radar [LidAR: Light Detection and Ranging].

[0034] The internal sensor 4 is a detection device that detects a state of the vehicle 2. The internal sensor 4 detects a running state of the vehicle 2 as the state of the vehicle 2. The running state includes a behavior of the vehicle. The internal sensor 4 includes, for example, a vehicle speed sensor, an acceleration sensor, and a yaw rate sensor as sensors that detect the running state of the vehicle 2. The vehicle speed sensor is a detection device that detects a speed of the vehicle 2. As the vehicle speed sensor, a wheel speed sensor that is provided to a wheel of the vehicle 2 or a drive shaft that rotates integrally with the wheel, and detects a rotational speed of each wheel can be used.

[0035] The acceleration sensor is a detection device that detects an acceleration of the vehicle 2. The acceleration sensor includes, for example, a front-rear acceleration sensor that detects an acceleration in a front-rear direction of the vehicle 2. The acceleration sensor can also include a lateral acceleration sensor that detects a lateral acceleration of the vehicle 2. The yaw rate sensor is a detection device that detects a yaw rate (rotational angular velocity) of a center of gravity of the vehicle 2 around a vertical axis. As the yaw rate sensor, for example, a gyro sensor can be used.

[0036] In addition, the internal sensor 4 detects a driving operation of the driver on the vehicle 2 as the state of the vehicle 2. The internal sensor 4 includes, for example, a steering sensor, an accelerator sensor, a brake sensor, and the like as sensors that detect the driving operation of the driver on the vehicle 2.

[0037] The steering sensor detects an amount of operation of the steering wheel by the driver. The amount of operation of the steering portion includes a steering angle. The amount of operation of the steering portion can also include a steering torque. The accelerator sensor detects an amount of operation of the accelerator pedal by the driver. The amount of operation of the accelerator pedal includes, for example, an amount of depression of the accelerator pedal. The brake sensor detects an amount of operation of the brake pedal by the driver. The amount of operation of the brake pedal includes, for example, an amount of depression of the brake pedal. The brake sensor can also detect a master cylinder pressure of a hydraulic brake system.

[0038] The environment sensor 5 is a detection device that detects environmental information of the surroundings of the vehicle 2. The environmental information is, for example, climate information or road surface information, and includes, as examples, at least one of a rainfall amount, a snowfall amount, a sunlight amount, an intensity of glare, and a degree of freezing of a road surface. The environment sensor 5 includes, for example, at least one of a rainfall sensor, a snowfall sensor, a sunlight sensor, and an air temperature sensor.

[0039] The vehicle system 6 is an in-vehicle system that assists driving of the vehicle 2. As an example, the vehicle system 6 can be an advanced driver-assistance system [ADAS]. The driving assistance provided by the vehicle system 6 can be a state in which driving operations including brake operations, accelerator operations, and steering wheel operations are partially automated, a state in which driving tasks are entirely automated on condition that a pre-set traveling condition is satisfied, or a state in which driving tasks are entirely automated without a condition being set.

[0040] As examples, the driving assistance includes a lane maintenance function, an inter-vehicle control function, a start function, a stop function, a lane change function, a left and right turn function, a collision warning function, a collision mitigation function, a parking function, a pedestrian detection function, and the like. The vehicle system 6 includes a plurality of ECUs [Electronic Control Units] in order to realize these functions. An ECU is an electronic control unit having a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], a CAN [Controller Area Network] communication circuit, and the like.

[0041] The ECU includes, for example, an instrument ECU, a body ECU, a navigation ECU, a communication control ECU, an engine ECU, a brake ECU, a power steering ECU, an airbag ECU, a transmission ECU, and the like.

[0042] The instrument ECU has a function of displaying the operation state of the switch group or a signal (vehicle speed, engine speed, door lock state, etc.) acquired from other ECUs. The body ECU detects the on / off of the door control switch, performs control of the interior light or door lock / unlock, etc. The navigation ECU has a route guidance, audiovisual function in addition to detecting position information of the vehicle using a GNSS [Global Navigation Satellite Systems] or the like and displaying a map and the own vehicle position. The communication control ECU is connected to a wireless communication network such as a mobile phone network, wireless LAN [Local Area Network], etc., and can transmit a part or all of the vehicle data to an external server by communicating with the external server. The engine ECU controls the throttle opening degree, fuel injection amount, ignition timing based on the accelerator opening degree, crank angle. The brake ECU performs ABS [Anti-lock Brake System] control, TRC [Traction Control] control, ESC [Electronic Stability Control] control based on the rotational speed of each wheel to detect the slip.

[0043] The power steering ECU detects the steering torque of the driver, drives a motor to perform steering assist, and in addition, during the operation of an LKA [Lane Keeping Assist system] system, rotates a steering shaft to travel in the center of a travel lane. The airbag ECU analyzes the acceleration / deceleration, lateral acceleration acting on the vehicle, and deploys a corresponding airbag. The transmission ECU opens and closes a valve through which transmission oil passes, and switches gears based on the engine speed increase / decrease, acceleration, vehicle speed, etc. based on the accelerator opening degree, brake operation. In this way, the driving assist is realized by the ECU causing the constituent elements of the vehicle 2 to operate based on the detection results of the external sensors 3 and the internal sensors 4.

[0044] The storage device 7 is a storage medium that stores vehicle data. The storage device 7 is constituted by a memory or a hard disk, etc. The storage device 7 can be configured to have a volatile memory that temporarily stores vehicle data, and a non-volatile memory that constitutes a ring buffer and stores vehicle data for a prescribed period.

[0045] The data storage device 1 is directly or indirectly connected to the external sensors 3 and the internal sensors 4, and stores the detection results of the external sensors 3 and the internal sensors 4 in the storage device 7. The data storage device 1 can also be directly or indirectly connected to the vehicle systems 6, and stores the output values of the vehicle systems 6 in the storage device 7. Hereinafter, at least one of the detection results of the external sensors 3, the detection results of the internal sensors 4, and the output values of the vehicle systems will be referred to as vehicle data.

[0046] The data storage device 1 is provided with a control section 11 and an acquisition section 12. The control section 11 and the acquisition section 12 are configured as an ECU, for example.

[0047] The control section 11 stores vehicle data corresponding to a vehicle condition in the storage device 7 in response to detection of a predetermined vehicle condition. The predetermined vehicle condition can be arbitrarily set in correspondence with a prescribed event. For example, the vehicle condition can be set as a condition in which the driver is likely to encounter an unsafe event.

[0048] The vehicle condition can be prescribed by a driving state of the vehicle 2, for example. The driving state can include, for example, an ignition ON, an ignition OFF, and the like, which are related to the start and stop of the vehicle. The driving state can also include a state in which at least one of a speed, an acceleration, a deceleration, and a lateral acceleration is equal to or greater than a predetermined value, a state in which a yaw rate is equal to or greater than a predetermined value, a start state, a stop state, and the like. The vehicle condition can be prescribed by a predetermined relationship between the vehicle 2 and a surrounding object. In this case, the vehicle condition can include a condition in which the vehicle 2 is likely to come into contact with the surrounding object. The vehicle condition can include, for example, a condition in which a TTC [Time To Collision] is equal to or less than a predetermined value. The vehicle condition can also be prescribed by an action state of the vehicle system 6, such as an automatic brake action, an airbag deployment, and the like. The vehicle condition can also be set as a condition in which the vehicle system 6 is not normal, such as a condition in which an error message is output from the vehicle system 6, and the like.

[0049] The predetermined vehicle condition can be detected by the control section 11 or by another ECU or the like. Hereinafter, a case in which the control section 11 detects the predetermined vehicle condition will be described. The control section 11 can detect the predetermined vehicle condition based on at least one of a detection result of the external sensor 3, a detection result of the internal sensor 4, and an output value of the vehicle system 6.

[0050] The control section 11 decides vehicle data corresponding to the detected vehicle condition and stores it in the storage device 7 in response to detection of the predetermined vehicle condition. Thus, the storage device 7 holds vehicle data corresponding to each vehicle condition, and therefore, it becomes easy to analyze afterward.

[0051] The acquisition section 12 acquires environmental information of the surroundings of the vehicle 2. The acquisition section 12 is connected to the environmental sensor 5, for example, and inputs a detection result of the environmental sensor 5. The acquisition section 12 can also be configured to receive environmental information from a server or the like, which is not illustrated.

[0052] The control section 11 has a function of adjusting the data amount of the vehicle data stored in the storage device 7 based on the environmental information acquired by the acquisition section 12. For example, the control section 11 decides the sampling frequency of the vehicle data stored in the storage device 7 based on the environmental information acquired by the acquisition section 12 and a previously acquired relationship between the environmental information and the sampling frequency of the vehicle data. For example, the control section 11 temporarily stores the vehicle data in the volatile memory of the storage device 7, and then samples and extracts the vehicle data stored in the volatile memory at a prescribed sampling frequency, and stores the extracted vehicle data in the nonvolatile memory of the storage device 7. That is, the adjustment of the data amount by the control section 11 is not targeted at the temporary storage in the volatile memory in the storage device 7, but at the storage in the nonvolatile memory capable of storing for a certain period.

[0053] Figure 2 is a graph showing the relationship between the sampling frequency of the vehicle data and the estimated one-hour rainfall, and the relationship between the assumed occurrence number of a prescribed event and the estimated one-hour rainfall. The horizontal axis is the estimated one-hour rainfall [mm], the left vertical axis is the sampling frequency of the vehicle data [Hz], and corresponds to the solid line. The right vertical axis is the assumed occurrence number of a prescribed event, and corresponds to the one-dot chain line. Here, the prescribed event is an event in which the possibility of the driver encountering an unsafe event is high.

[0054] As shown by the curve Ll of Figure 2 , the assumed occurrence number of a prescribed event is estimated to be almost constant and not change until a prescribed rainfall amount (for example, 15 [mm]) is reached, and to increase in proportion to the rainfall amount when the prescribed rainfall amount (for example, 15 [mm]) is exceeded. This is because, if it is a certain degree of rain, the field of view is also good, but the field of view deteriorates from the prescribed rainfall amount. Also, it is because, although the driver is also accustomed to rain of a certain degree of rainfall amount, experience is less when the prescribed rainfall amount is exceeded. Therefore, if the number of acquired data is set to N, as shown by the curve L2 of Figure 2 , the sampling frequency is set to N [Hz] until the prescribed rainfall amount (for example, 15 [mm]) is reached, and is set to increase in stages when the prescribed rainfall amount (for example, 15 [mm]) is exceeded.

[0055] In the example of Figure 2 , the sampling frequency is set to 2N [Hz] in the range of rainfall amount 15 [mm] to 25 [mm], to 3N [Hz] in the range of rainfall amount 25 [mm] to 35 [mm], and to 4N [Hz] in the range of rainfall amount 35 [mm] to 45 [mm]. The sampling frequency is set to 5N [Hz] after the rainfall amount 45 [mm], and is not set to a value above that. That is, a frequency upper limit value ULl is set to the sampling frequency.

[0056] Figure 3 (A) is a graph showing the relationship between the amount of data obtained at the first sampling frequency and time. Figure 3 (B) is a graph showing the relationship between the amount of data obtained at a second sampling frequency, which is higher than the first sampling frequency, and time. Figure 3 (A) and Figure 3 In (B), the horizontal axis represents time, and the vertical axis represents data volume. Data points are represented using circular graphs. For example... Figure 3 As shown in (A), the number of data points obtained at the first sampling frequency is 4. Figure 3 As shown in (B), 13 data points are obtained using a second sampling frequency, which is higher than the first sampling frequency. Thus, by increasing the sampling frequency, the number of data points increases, and the data volume also increases. In other words, under conditions of heavy rainfall, the data storage device 1 can acquire data with greater precision.

[0057] The above is based on the control unit 11 Figure 2 The relationship between the sampling frequency of vehicle data and the estimated hourly rainfall is shown. By controlling the sampling frequency, it is possible to detect events that are likely to occur, such as... Figure 3 The amount of vehicle data stored is increased as shown. Furthermore, by employing a configuration that increases the sampling frequency, the capacity of the storage device 7 may be reduced. The control unit 11 can prevent the capacity of the storage device 7 from being unintendedly reduced by setting a frequency upper limit value UL1.

[0058] [Operation of the data storage device]

[0059] Figure 4 (A) is a flowchart illustrating the action of the data storage device in determining the sampling frequency of vehicle data. Figure 4 The flowchart shown in (A) is executed by the data storage device 1, for example, when the operator's operation is received.

[0060] like Figure 4 As shown in (A), the acquisition unit 12 of the data storage device 1 acquires the rainfall amount in step S10. The acquisition unit 12 acquires the rainfall amount, for example, based on the detection result of the environmental sensor 5. Next, as step S12, the control unit 11 of the data storage device 1 determines the sampling frequency. The control unit 11 determines the sampling frequency based on the rainfall amount obtained in step S10 and... Figure 2 The sampling frequency is determined by the relationship between the sampling frequency of the vehicle data shown and the estimated hourly rainfall. For example, if the rainfall obtained in step S10 is 20 mm, the control unit 11 sets the sampling frequency to 2N. When step S12 ends, Figure 4The flowchart shown in (A) ends. The flowchart can also be executed repeatedly from the beginning before receiving an end operation. In this case, the data storage device 1 can dynamically change the sampling frequency.

[0061] Figure 4 (B) is a flowchart illustrating the operation of the data storage device storing vehicle data. Figure 4 The flowchart shown in (B) is in Figure 4 After the flowchart shown in (A) is executed, for example, at the moment when the occupant's operation is received, it is executed by the data storage device 1.

[0062] like Figure 4 As shown in (B), as step S20, the control unit 11 of the data storage device 1 determines whether a predetermined vehicle condition has been detected. The control unit 11 detects the predetermined vehicle condition based on at least one of the detection results of the external sensor 3, the detection results of the internal sensor 4, and the output value of the vehicle system 6. If the predetermined vehicle condition is detected (step S20: "Yes"), as step S22, the control unit 11... Figure 4 The sampling frequency determined in the flowchart shown in (A) stores the vehicle data in the non-volatile memory of storage device 7.

[0063] If step S22 has ended, or if the specified vehicle condition has not been detected (step S20: "No"), the process ends. Figure 4 The flowchart is shown in (B). The flowchart can also be executed repeatedly from the beginning before receiving a termination operation. In this case, the data storage device 1 can dynamically store vehicle data.

[0064] [Summary of Implementation Methods]

[0065] The data storage device 1 acquires environmental information about the surrounding environment of vehicle 2. Then, based on the acquired environmental information and a pre-established relationship between the environmental information and the sampling frequency, the sampling frequency for storing vehicle data in storage device 7 is determined. Then, in response to the detection of a pre-defined vehicle condition, vehicle data sampled at the determined sampling frequency is stored in the storage device. Thus, because the data storage device 1 can change the sampling frequency of the vehicle data according to the environmental information, it can adjust the amount of vehicle data stored based on the surrounding environment of vehicle 2.

[0066] The data storage device 1 can increase the amount of vehicle data stored in environments that impede the movement and driving of the vehicle 2, i.e., situations where the driver is more likely to encounter unsafe events. Therefore, compared to devices that store all vehicle data, the data storage device 1 can improve event analysis capabilities.

[0067] [Variation Example]

[0068] The above describes the illustrative implementation method, but it is not limited to the illustrative implementation method described above, and various omissions, substitutions and changes can be made.

[0069] [Processing of other environmental information]

[0070] In the above embodiments, the case where the environmental information is rainfall has been described in detail. However, when the environmental information is snowfall, sunshine duration, intensity of backlighting, or degree of road icing, the same method can be used as when the environmental information is rainfall. That is, as long as it is the same as... Figure 2 Similarly, prepare the relationship between at least one of the following: snowfall, sunshine, backlight intensity, and road surface icing degree, and sampling frequency.

[0071] [Sampling frequency control]

[0072] Data storage device 1 in Figure 2 In curve L2, when the rainfall exceeds 15 mm, the sampling frequency is increased in stages, but it can also be increased proportionally, i.e., linearly. Furthermore, the data storage device 1 can also change the sampling frequency by combining time parameters with environmental information. For example, when a certain amount of rainfall persists for more than a predetermined time, the driver's attention will decrease, thus allowing the data storage device 1 to acquire a large amount of data. Alternatively, the data storage device 1 can also combine traffic information or driving information with environmental information to change the sampling frequency. For example, the data storage device 1 can change the sampling frequency by acquiring a large amount of data when entering an area with frequent traffic disputes, entering an intersection, entering an area where a certain amount of traffic persists for more than a predetermined time, driving for more than a predetermined time, or while driving distractedly.

[0073] [Other examples of increasing data volume]

[0074] The method of changing the sampling frequency based on environmental information such as rainfall is a method of adjusting the amount of data by controlling the number of data acquisitions based on environmental information. Conversely, the amount of data can also be increased by acquiring the data more precisely. The method of acquiring the data more precisely can be used in combination with the method of increasing the amount of data by increasing the number of data acquisitions, or it can be used alone. For example, the method of acquiring the data more precisely is used when the vehicle data is image data. Image data is acquired by external sensor 3 and stored directly or via vehicle system 6 in storage device 7. An example of such image data is the image from a front-facing camera, or raw image data of a top-down view displayed during parking assistance.

[0075] Figure 5 This is a graph showing the relationship between the number of pixels in image data and the estimated hourly rainfall, as well as the relationship between the number of hypothetical occurrences of a specified event and the estimated hourly rainfall. The horizontal axis represents the estimated hourly rainfall [mm], and the left vertical axis represents the number of pixels in the image data [pixels], corresponding to the solid line curve. The right vertical axis represents the number of hypothetical occurrences of a specified event, corresponding to the dashed line curve. Here, a specified event is an event in which the driver has a high probability of encountering an unsafe situation.

[0076] like Figure 5 As shown by curve L3, the hypothetical occurrence number of the specified event is presumed to be constant until a specified rainfall amount (e.g., 15 mm) is reached, and then increases proportionally to the rainfall amount when the specified rainfall amount (e.g., 15 mm) is exceeded. Therefore, as... Figure 5 As shown in curve L3, the number of pixels is set to A before a specified rainfall amount (e.g., 15 mm) is reached. B[pix] is set to increase in stages when the rainfall exceeds a specified amount (e.g., 15[mm]).

[0077] exist Figure 5 In the example, the number of pixels is set to 2 (A) for rainfall ranging from 15 mm to 25 mm. B) [pix], set to 3 (A) within the rainfall range of 25 [mm] to 35 [mm]. B) [pix], set to 4 (A) within the rainfall range of 35 [mm] to 45 [mm]. B) [pixel]. The number of pixels is set to 5 after rainfall reaches 45 [mm]. B) [pix], do not set a value higher than this. In other words, a maximum pixel count of UL2 is set.

[0078] Control unit 11 based on Figure 5 The relationship between the number of pixels in the image data and the estimated hourly rainfall is shown. By controlling the number of pixels in the image data, the system can operate by increasing the amount of stored image data in situations where a predetermined event is likely to occur. However, by employing a configuration that increases the number of pixels, the capacity of the storage device 7 may be reduced. The control unit 11 prevents the capacity of the storage device 7 from being unexpectedly reduced by setting a pixel count upper limit value UL2.

[0079] [Example of setting the number of times data can be saved]

[0080] The data storage device 1 can also be configured to save a specified number of times within a given period for each category of vehicle condition. The number of times a vehicle condition can be saved specifies how many sets of a particular vehicle condition will be stored in the non-volatile memory of the storage device 7. The number of times a vehicle condition can be arbitrarily set based on the assumed frequency of occurrence of the vehicle condition and the desired storage and retention period (the specified period). For example, if the assumed frequency of occurrence is 5 times per week and the specified period is 1 week, then the number of times a vehicle condition can be saved is 5. The categories of vehicle conditions are defined to distinguish various vehicle conditions, such as vehicle conditions related to starting and stopping the vehicle, such as ignition ON and ignition OFF; conditions where at least one of speed, acceleration, deceleration, and lateral acceleration is above a predetermined value; conditions where the yaw rate is above a predetermined value; starting state; stopping state; conditions where TTC is below a predetermined value; automatic braking action; airbag deployment and other vehicle system 6 operation conditions; and conditions where error information is output from vehicle system 6.

[0081] Figure 6 This is a table showing the relationship between vehicle condition categories and the number of times the data can be saved. For example... Figure 6 As shown, each vehicle condition category is associated with a number of saveable times, such that vehicle condition A is saved 3 times, vehicle condition B is saved 5 times, and vehicle condition C is saved 10 times. (See reference...) Figure 6 As shown in the table, in response to detecting a vehicle condition, the control unit 11 stores vehicle data in the non-volatile memory of the storage device 7 if the number of times the data to be saved related to the vehicle condition is less than the number of times it can be saved, and does not store vehicle data in the non-volatile memory of the storage device 7 if the number of times the data to be saved related to the vehicle condition is greater than or equal to the number of times it can be saved. Thus, the data storage device 1 can avoid unintended capacity constraints on the storage device 7.

[0082] The number of times the data storage device 1 can be saved can also be adjusted according to the actual data. Figure 7 This is a flowchart illustrating the action of changing the number of times the data can be saved. Figure 7 The flowchart shown illustrates the execution by data storage device 1 for each category of vehicle condition after a specified period.

[0083] like Figure 7 As shown, in step S30, the control unit 11 of the data storage device 1 determines whether there is a difference between the actual number of saves and the number of saves within a specified period. If it is determined that there is a difference between the actual number of saves and the number of saves within the specified period (step S30: "Yes"), in step S32, the control unit 11 determines whether the number of saves is a lower limit value. The lower limit value is, for example, preset for each vehicle condition. The lower limit value can also be a common value set for all vehicle conditions.

[0084] If the number of times a data can be saved is determined to be less than the lower limit (step S32: "No"), as step S34, the control unit 11 reduces the number of times a data can be saved by 1. If the number of times a data can be saved is determined to be less than the lower limit (step S32: "Yes"), as step S36, the control unit 11 maintains the number of times a data can be saved.

[0085] If there is no difference between the actual number of saves and the number of saves that can be made within the specified period (step S30: "No"), if step S34 has ended, or if step S36 has ended. Figure 7 The flowchart shown ends here. This is achieved through execution. Figure 7 As shown in the flowchart, the data storage device 1 can increase the amount of vehicle data stored when the probability of the driver encountering an unsafe event is high, and can stop unnecessary storage according to the driver's preferences, thus achieving a balance between the quality and capacity of vehicle data recording.

[0086] [Data Storage System]

[0087] Data storage device 1 can also be provided as a data storage system. Figure 8 This is a block diagram illustrating an example of the configuration of a data storage system according to one embodiment. For example... Figure 8 As shown, the data storage system 100 is applied to an environment containing a vehicle 2 and a server 20. The data storage system 100 includes a data storage device 1. The vehicle 2 differs from the embodiment described above in that it does not have the data storage device 1 and storage device 7; otherwise, it is the same as the embodiment described above. The server 20 is configured to communicate with the vehicle 2 and is a general-purpose computer including a CPU, ROM, RAM, etc. The server 20 includes the data storage device 1 and storage device 7. Thus, the data storage device 1 and storage device 7 described in the above embodiment can be installed not only in the vehicle 2 but also in devices such as the server 20 that can communicate with the vehicle 2. Alternatively, only a portion of the data storage device 1 and storage device 7 may be installed in the server 20. In either case, the data storage system 100 functions the same as the data storage device 1.

[0088] [program]

[0089] The various functions of data storage device 1 can also be provided as programs. Programs can be provided, for example, by storing them on a computer-readable recording medium.

[0090] This disclosure includes the following items as shown.

[0091] [Project 1] A data storage device, comprising:

[0092] The control unit, in response to detecting a pre-defined vehicle condition, stores vehicle data corresponding to the vehicle condition in a storage device; and

[0093] The acquisition unit acquires environmental information about the vehicle's surroundings.

[0094] The control unit determines the sampling frequency of the vehicle data to be stored in the storage device based on the environmental information obtained by the acquisition unit and a pre-obtained relationship between the environmental information and the sampling frequency of the vehicle data, and stores the vehicle data sampled at the determined sampling frequency in the storage device.

[0095] [Project 2] The data storage device according to Project 1, wherein,

[0096] The environmental information includes at least one of the following: rainfall, snowfall, sunshine, intensity of backlight, and degree of road icing.

[0097] The pre-established relationship between the environmental information and the sampling frequency of the vehicle data is that the larger the environmental information, the larger the sampling frequency of the vehicle data.

[0098] [Item 3] The data storage device according to Item 1, wherein,

[0099] The environmental information includes at least one of the following: rainfall, snowfall, sunshine, intensity of backlight, and degree of road icing.

[0100] The pre-established relationship between the environmental information and the sampling frequency of the vehicle data is that the sampling frequency of the vehicle data increases in stages according to the magnitude of the environmental information.

[0101] [Item 4] A data storage device according to any one of Items 1 to 3, wherein,

[0102] The control unit sets an upper limit on the sampling frequency of the vehicle data.

[0103] [Item 5] A data storage device according to any one of Items 1 to 4, wherein,

[0104] The vehicle data includes image data.

[0105] The control unit determines the number of pixels of the image data to be stored in the storage device based on the environmental information obtained by the acquisition unit and a pre-obtained relationship between the environmental information and the number of pixels of the image data, and stores the image data after converting it to the determined number of pixels in the storage device.

[0106] [Item 6] A data storage device according to any one of Items 1 to 5, wherein,

[0107] The control unit performs the following processing:

[0108] For each category of vehicle condition, a specified number of save attempts are allowed within a given period.

[0109] In response to the detection of the vehicle condition, if the number of times the data related to the vehicle condition has been saved is less than the number of times it can be saved, the vehicle data is stored in the storage device; if the number of times the data related to the vehicle condition has been saved is greater than the number of times it can be saved, the vehicle data is not stored in the storage device.

[0110] Obtain the actual value of the number of times data is saved within the specified period.

[0111] The number of times that can be saved is adjusted in a manner that approximates the actual performance value.

[0112] [Item 7] A vehicle, comprising:

[0113] The control unit, in response to detecting a pre-defined vehicle condition, stores vehicle data corresponding to the vehicle condition in a storage device; and

[0114] The acquisition unit acquires environmental information about the vehicle's surroundings.

[0115] The control unit determines the sampling frequency of the vehicle data to be stored in the storage device based on the environmental information obtained by the acquisition unit and a pre-obtained relationship between the environmental information and the sampling frequency of the vehicle data, and stores the vehicle data sampled at the determined sampling frequency in the storage device.

[0116] [Project 8] A data storage system, comprising:

[0117] The control unit, in response to detecting a pre-defined vehicle condition, stores vehicle data corresponding to the vehicle condition in a storage device; and

[0118] The acquisition unit acquires environmental information about the vehicle's surroundings.

[0119] The control unit determines the sampling frequency of the vehicle data to be stored in the storage device based on the environmental information obtained by the acquisition unit and a pre-obtained relationship between the environmental information and the sampling frequency of the vehicle data, and stores the vehicle data sampled at the determined sampling frequency in the storage device.

[0120] [Item 9] A computer-readable recording medium storing a program executed by a control unit in a data storage device, the data storage device comprising: the control unit, which, in response to detecting a predetermined vehicle condition, stores vehicle data corresponding to the vehicle condition in the storage device; and an acquisition unit, which acquires environmental information surrounding the vehicle, wherein when the program is executed by the control unit, the control unit performs the following steps:

[0121] The step of determining the sampling frequency of the vehicle data to be stored in the storage device based on the environmental information obtained by the acquisition unit and a pre-obtained relationship between the environmental information and the sampling frequency of the vehicle data; and

[0122] The step of storing the vehicle data sampled at the determined sampling frequency in the storage device.

Claims

1. A data storage device, comprising: The control unit, in response to detecting a pre-defined vehicle condition, stores vehicle data corresponding to the vehicle condition in a storage device; and The acquisition unit acquires environmental information about the vehicle's surroundings. The control unit determines the sampling frequency of the vehicle data to be stored in the storage device based on the environmental information obtained by the acquisition unit and a pre-obtained relationship between the environmental information and the sampling frequency of the vehicle data, and stores the vehicle data sampled at the determined sampling frequency in the storage device.

2. The data storage device according to claim 1, wherein, The environmental information includes at least one of the following: rainfall, snowfall, sunshine, intensity of backlight, and degree of road icing. The pre-established relationship between the environmental information and the sampling frequency of the vehicle data is that the larger the environmental information, the larger the sampling frequency of the vehicle data.

3. The data storage device according to claim 1, wherein, The environmental information includes at least one of the following: rainfall, snowfall, sunshine, intensity of backlight, and degree of road icing. The pre-established relationship between the environmental information and the sampling frequency of the vehicle data is that the sampling frequency of the vehicle data increases in stages according to the magnitude of the environmental information.

4. The data storage device according to any one of claims 1 to 3, wherein, The control unit sets an upper limit on the sampling frequency of the vehicle data.

5. The data storage device according to any one of claims 1 to 3, wherein, The vehicle data includes image data. The control unit determines the number of pixels of the image data to be stored in the storage device based on the environmental information obtained by the acquisition unit and a pre-obtained relationship between the environmental information and the number of pixels of the image data, and stores the image data after converting it to the determined number of pixels in the storage device.

6. The data storage device according to any one of claims 1 to 3, wherein, The control unit performs the following processing: For each category of vehicle condition, a specified number of saves is allowed within a given period. In response to the detection of the vehicle condition, if the number of times the data related to the vehicle condition has been saved is less than the number of times it can be saved, the vehicle data is stored in the storage device; if the number of times the data related to the vehicle condition has been saved is greater than the number of times it can be saved, the vehicle data is not stored in the storage device. Obtain the actual value of the number of times the data is stored within the specified period. The number of times that can be saved is adjusted in a manner that approximates the actual performance value.

7. A vehicle, comprising: The control unit, in response to detecting a pre-defined vehicle condition, stores vehicle data corresponding to the vehicle condition in a storage device; and The acquisition unit acquires environmental information about the vehicle's surroundings. The control unit determines the sampling frequency of the vehicle data to be stored in the storage device based on the environmental information obtained by the acquisition unit and a pre-obtained relationship between the environmental information and the sampling frequency of the vehicle data, and stores the vehicle data sampled at the determined sampling frequency in the storage device.

8. A data storage system, comprising: The control unit, in response to detecting a pre-defined vehicle condition, stores vehicle data corresponding to the vehicle condition in a storage device; and The acquisition unit acquires environmental information about the vehicle's surroundings. The control unit determines the sampling frequency of the vehicle data to be stored in the storage device based on the environmental information obtained by the acquisition unit and a pre-obtained relationship between the environmental information and the sampling frequency of the vehicle data, and stores the vehicle data sampled at the determined sampling frequency in the storage device.

9. A computer-readable recording medium storing a program executed by a control unit in a data storage device, the data storage device comprising: the control unit, which, in response to detecting a predetermined vehicle condition, stores vehicle data corresponding to the vehicle condition in the storage device; and an acquisition unit, which acquires environmental information surrounding the vehicle, wherein when the program is executed by the control unit, the control unit performs the following steps: The step of determining the sampling frequency of the vehicle data to be stored in the storage device based on the environmental information obtained by the acquisition unit and a pre-obtained relationship between the environmental information and the sampling frequency of the vehicle data; and The step of storing the vehicle data sampled at the determined sampling frequency in the storage device.

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