JP2022031185A - Drive recorder storage device control method and storage device control system - Google Patents

Abstract

A drive recorder storage device control method for configuring a storage device according to a predetermined file allocation table (FAT) and a predetermined directory entry to prevent reading failure due to unexpected power failure. A method for controlling a storage device of a drive recorder includes steps of configuring a directory entry of the storage device according to a predetermined directory entry stored in the storage unit, and storing according to a predetermined file allocation table stored in the storage unit. Configuring a file allocation table for the device and controlling the controller to write data to the storage device according to the directory entries and the file allocation table. In one embodiment, entries in a given file allocation table are interleaved to accommodate multiple files and still support sequential write operations. [Selection drawing] Fig. 12A

Description

The present invention generally relates to control methods and control systems, and more particularly to control methods and storage device control systems for drive recorder storage devices.

The file system is a system for managing files in a storage device (for example, an SD card or a hard drive) and operating the storage device efficiently. File Allocation Table (FAT) is a common file system.

FIG. 1 shows a schematic diagram of a storage device 900 that employs a FAT file system. The storage device 900 includes a FAT 920, a directory entry 930, and a plurality of data clusters 940. Taking a drive recorder as an example, after multiple operations of writing and deleting a file, the data of the same file may be distributed and stored in the discontinuous data cluster 940. For example, as shown in FIG. 1, the file FA is stored in the data clusters of numbers "13", "14", "15", "19", and "20".

Directory entry 930 records the file name and start data cluster number in storage device 900. The FAT 920 records the FAT chain of the data cluster. For example, the directory entry 930 indicates that the file FA is stored in the storage device 900, and the data of the file FA is stored in the data cluster 940 of the number “13”. In the FAT 920, the position corresponding to the data cluster 940 of the number "13" is "14", which indicates that the data cluster 940 of the number "14" stores the subsequent data of the file FA. ing. In the FAT 920, the position corresponding to the data cluster 940 of the number "14" is "15", which indicates that the data cluster 940 of the number "15" stores the subsequent data of the file FA. The same applies to the following. In FAT920, the position corresponding to the data cluster 940 of the number "20" is "EOC", which means that the data cluster 940 of the number "20" is the end of the cluster chain (EOC) of the data cluster 940. Is shown.

FIG. 2 shows a flowchart of a method for writing a drive recorder file. FIG. 3 is a schematic diagram of a storage device 900 that operates according to FIG. For example, after the drive recorder recording process is activated, the FAT 920 in the storage device 900 is replicated to the dynamic random access memory (DRAM) (step S901). Then, according to the FAT in the DRAM, it is determined whether or not the storage space in the storage device 900 is sufficient (step S902). If the storage device 900 has sufficient storage space, one data cluster is selected as the starting data cluster for writing data (eg, the data cluster of number "16") (step S903) and the file name (step S903) in FAT930. For example, the FB) and the starting data cluster number (eg, "16") are added. Next, another data cluster for writing data (eg, the data cluster of number "17") is selected (step S905) and at the FAT in the DRAM at the position corresponding to the data cluster of number "16". The data cluster number (eg, "17") is recorded (step S906) and the data is written to the data cluster (step S907). The above steps are repeated until the file writing process is completed. Further, when the FAT in the DRAM is updated a predetermined number of times (for example, three times), the FAT 920 in the storage device 900 is updated according to the FAT in the DRAM until the file writing process is completed. When the file writing process is completed, the drive recorder updates the FAT 920 in the storage device 900 again according to the FAT in the DRAM.

However, an unexpected power loss due to a car accident can result in read errors due to an incomplete FAT chain. For example, as shown in FIG. 3, if an unexpected power failure occurs after the data in the file FB is written to the data cluster of number "29", the FAT 920 in the storage device 900 is still updated according to the FAT in the DRAM. Therefore, the FAT chain of the data FB is incomplete, and the data of the file FB stored in the data clusters of the numbers "22" and "29" cannot be read. For drive recorders, failing to read data about a car accident is a very serious problem.

The present invention relates to a drive recorder storage device control method and a storage device control system for configuring a storage device according to a predetermined file allocation table (FAT) and a predetermined directory entry to prevent a read failure due to an unexpected power failure.

According to one aspect of the present invention, a method for controlling a storage device of a drive recorder is provided. The drive recorder's storage device is controlled by the steps of configuring the directory entry of the storage device according to the predetermined directory entry stored in the storage unit and the storage device according to the predetermined file allocation table (FAT) stored in the storage unit. Includes a step of configuring the FAT and a step of controlling the controller to write data to the storage according to the directory entry and FAT.

According to another aspect of the invention, a storage device control system is provided. The storage device control system includes a storage unit, a controller, and a processor. The storage unit stores a predetermined directory entry and a predetermined FAT. The controller writes data to the storage device. The processor controls the controller to write data to the storage device according to the directory file and the FAT, the step of configuring the storage device directory entry according to the predetermined directory file, the step of configuring the storage device FAT according to the predetermined FAT, and the step. Step and execute.

According to another aspect of the present invention, a method for controlling a storage device of a drive recorder is provided. The method consists of a step of configuring the directory entry of the storage device according to a predetermined directory entry stored in the storage unit and a step of configuring the FAT of the storage device according to a predetermined file allocation table (FAT) stored in the storage unit. , Directory entries and steps to control the controller to write data to the storage according to the FAT, the entries in the FAT correspond to each given cluster in the storage, and each entry in the FAT It remains unchanged after new data is written to each given cluster in storage.

According to one aspect of the invention, the data comprises data from at least two files and the FAT is configured to store the two files in an interleaved cluster.

According to another aspect of the invention, the at least two files are video files having the same bit rate, and the step of configuring the FAT of the storage device is to have the same number of predetermined clusters in each of the at least two files. Includes steps to assign.

According to yet another aspect of the invention, the at least two files are video files having different bit rates from each other, and the steps constituting the FAT of the storage device are at least two according to the bit rates of the at least two files. Includes a step to assign a given cluster to each of the files.

According to another embodiment, a storage device control system is provided. The system includes a storage unit that stores a predetermined directory entry and a predetermined file allocation table (FAT), a controller that writes data to the storage device, and a processor, and the processor follows the predetermined directory entry of the storage device. Performs the steps of configuring a directory entry, configuring the FAT of a storage device according to a given FAT, and controlling the controller to write data to the storage device according to the directory entry and FAT, and the entries in the FAT. Corresponds to each given cluster in the storage, and each entry in the FAT remains unchanged after new data is written to each given cluster in the storage.

The above and other aspects of the invention will be better understood with respect to the following detailed description of non-limiting embodiments. Hereinafter, description will be given with reference to the drawings.

It is a schematic diagram of the storage device which adopts the FAT file system of the prior art. It is a flowchart of the method for writing the file of the drive recorder of the prior art. It is a schematic diagram of the storage device which performs the operation of FIG. It is a block diagram of the control system by one Embodiment of this invention. It is a flowchart of the control method of the storage device of the drive recorder by one Embodiment of this invention. FIG. 3 is a schematic diagram of a storage device in which a directory file and a file allocation table (FAT) are configured according to an embodiment of the present invention. It is a flowchart of data writing to a storage device by one Embodiment of this invention. FIG. 3 is a schematic diagram of a storage device that executes the operation of FIG. 7. The configuration of the preconfigured continuous data cluster according to one embodiment of the present invention is shown. An embodiment of the present invention illustrates the configuration of a preconfigured continuous data cluster that supports multiple files from different or same applications. It is a schematic diagram which shows the potential defect of the file storage method shown in FIG. It is a schematic diagram which shows the potential defect of the file storage method shown in FIG. FIG. 3 is a schematic diagram of a storage device comprising an interleaved FAT according to an embodiment of the present invention. An embodiment of the present invention shows a method of storing data in a plurality of clusters, which is consistent with the interleaving method. FIG. 3 is a schematic representation of a storage device comprising a modified, interleaved FAT according to an embodiment of the invention. A method of storing data in a plurality of clusters, which is consistent with the modified interleaving method, according to an embodiment of the present invention is shown. FIG. 3 is a schematic representation of a storage device comprising another modified, interleaved FAT according to an embodiment of the invention. Shown is a method of storing data in a plurality of clusters according to an embodiment of the present invention, which is consistent with another modified interleaving method.

Considering the problems of the storage device of the drive recorder of the prior art, the present invention configures the FAT and the directory entry of the storage device according to the predetermined file allocation table (FAT) and the predetermined directory entry, and reads due to an unexpected power failure. A drive recorder control method for preventing failures and a storage device control system are provided.

FIG. 4 shows a block diagram of a control system 100 according to an embodiment of the present invention. For example, the control system 100 is a control chip. In this embodiment, the control system 100 is connected to the video camera 200 and the storage device 400. The control system 100 and the video camera 200 may be provided in, for example, a drive recorder. The storage device 400 is, for example, an SD card or a hard drive, and may be built in or external to the drive recorder. The control system 100 includes a storage unit 110, a controller 120, and a processor 130. The storage unit 110 stores a predetermined directory entry and a predetermined FAT. The controller 120 writes data to the storage device 400. Processor 130 constitutes a directory entry and FAT for storage device 400.

FIG. 5 shows a flowchart of a method for controlling a storage device of a drive recorder according to an embodiment of the present invention. In this embodiment, the processor 130 checks whether a directory entry and a FAT are present in the storage device 400 each time the drive recorder is started or the storage device 400 is replaced (step S501). If not present, processor 130 configures the directory entry and FAT directly in storage device 400 according to a given directory entry and given FAT in storage 110 (step S503), and if present, processor 130 further configures the directory entry and FAT. It is confirmed whether the directory entry and the FAT in the storage device 400 are the same as the predetermined directory entry and the predetermined FAT in the storage unit 110 (step S502). If different, the processor 130 directly configures the directory entry and FAT in the storage device 400 according to the predetermined directory entry and the predetermined FAT in the storage unit 110 (step S503).

FIG. 6 shows a schematic diagram of a storage device 400 in which a directory entry and a FAT are configured according to an embodiment of the present invention. The storage device 400 includes a FAT 420 configured according to a predetermined FAT, a directory entry 430 configured according to a predetermined FAT, and a plurality of data clusters 440.

As shown in FIG. 6, in the directory entry 430, the processor 130 configures the file name FC corresponding to the file and the start data cluster corresponding to the file FC as the data cluster of number "11", and in the FAT 420, the processor 130. Further configures the FAT chain corresponding to the file FC as a data cluster of numbers "11" to "15". Similarly, in directory entry 430, processor 130 configures the corresponding file name FD and the starting data cluster corresponding to file FD as the data cluster of number "16", and in FAT 420, processor 130 further comprises file FD. The FAT chain corresponding to is configured as a data cluster of numbers "16" to "20".

That is, the data of the file FC is set in advance so as to be stored in the data clusters of the numbers "11" to "15", and the data of the file FD is stored in the data clusters of the numbers "16" to "20". Is preset. Although the directory entries 430 and FAT 420 are already configured, in the storage device 400, as shown in FIG. 6, the data clusters corresponding to the file FC and the file FD (that is, the data of the numbers "11" to "20" (that is, the data of the numbers "11" to "20"). The cluster) is not stored with the data corresponding to the file FC and file FD.

FIG. 7 shows a flowchart of data writing to the storage device 400 according to the embodiment of the present invention. In this embodiment, the processor 130 controls the controller 120 to write data to the storage device 400 according to directory entries 430 and FAT 420.

For example, when the drive recorder starts recording, processor 130 selects a file for writing data according to directory entry 430 (step S704). In one embodiment, the file name in the directory entry 430 carries time information, so that the processor 130 can select the oldest file for writing data according to the file name in the directory entry 430. For example, looking at FIG. 6, file FC is the oldest file.

Next, the processor 130 renames the file in the directory entry 430 corresponding to that file (step S705). Following the above example, processor 130 changes the file name of the file selected by processor 130 to write data in directory entry 430 from "FC" to "FE", as shown in FIG. Note that in directory entry 430, the starting data cluster corresponding to file FE has not changed and is still the data cluster numbered "11". Further, in FAT 420, the FAT chain corresponding to the file FE is unchanged and remains the data cluster of numbers "11" to "15".

The processor 130 controls the controller 120 to write data to the data cluster in the storage device 400 configured for the file (step S706). Following the above example, the processor 130 controls the controller 120 to sequentially write data to the data clusters numbered "11" to "15" in the storage device 400, as shown in FIG.

Next, the processor 130 determines whether to continue writing the data (step S707). If the writing of data is continued, steps S704 to S706 are repeated, otherwise the process ends.

From the above, it can be seen that the FAT 420 is not updated in the process in which the processor 130 writes data to the storage device 400. Therefore, even if the drive recorder encounters an unexpected power failure, the FAT chain corresponding to the file in the FAT is maintained as it is, and the data in the file in the storage device 400 can still be completely read.

Moreover, in the prior art, the processor would have to spend time searching for an empty data cluster to write the data. After multiple operations of writing and deleting files, empty data clusters are usually in fragments, which reduces file write performance. Compared to prior art, the data clusters of files in the present invention are preconfigured and unchanged, which means that the processor does not have to spend time searching for empty clusters to write data to. However, this improves the file writing performance. In one embodiment, the cluster of files may be configured as contiguous (as shown in FIG. 6) to further improve file write performance.

Further, in the prior art, the processor needs to determine if there is enough space available before writing the data. If there is insufficient space available, the processor must remove the filename and start data cluster corresponding to at least one file from the directory entry, and FAT the FAT chain corresponding to at least one file. Must be removed from, which reduces file write performance. Compared to prior art, the processor 130 of the present invention also needs to determine if there is enough space available before writing data, it also removes the filename and start data cluster from the directory file and from the FAT. Since it is not necessary to delete the FAT chain, the file writing performance is further improved.

FIG. 9 shows the configuration of a preconfigured continuous data cluster according to an embodiment of the present invention. As described in connection with FIG. 6, if the FAT is preconfigured in the form of a continuous data cluster, the files are sequentially stored in the cluster as shown in FIG. That is, for example, in a secure digital (SD) card, the memory is divided into N sections, each section having, for example, 1000 consecutive clusters of data space. The files are written sequentially in these N sections, and the new file cyclically overwrites the old old file. The technique shown in FIG. 9 works well, for example, for simple applications that record only one video file at a time, but as the complexity of the product application increases, for example, two or more videos (or other) at the same time. More and more applications can record (type) files.

In this regard, FIG. 10 shows the configuration of a preconfigured continuous data cluster that supports multiple files from different applications according to one embodiment of the invention. For example, two types of files, in the form of large / small files, corresponding to higher resolution and lower resolution video, respectively, can be stored in memory at substantially the same time. In another example, for example, a multi-lens application may be implemented that includes video files corresponding to the front and rear lenses, also stored in memory at substantially the same time. Therefore, as shown in FIG. 10, in one example, the front (F) camera and the rear (R) camera are assigned the same number of sections (eg, N) to store the video file. If the recording time of each video file is, for example, 1 minute, the F file X and the R file X will be written simultaneously over 1 minute.

11A and 11B are schematics showing the potential drawbacks of the file storage technique shown in FIG. In FIG. 11A, SD storage 1110 includes boot sectors 1120, FAT 1130, directory entries 1140, and multiple data clusters 1150, which are also logically shown as 1160 and 1170 in FIG. 11B. Further, in a situation where two video files are desired to be stored at the same time, for example, the conventional method of writing the F file X and the R file X to the SD storage 1110 at the same time is such that the F file X is in the clusters 1100 to 2099 as shown in FIG. 11B. It depends on the storage by the cluster, which is continuously stored and the R file X is continuously stored in the clusters 20100 to 21099. In this case, the FAT1130 is preconfigured to store different files in a given cluster.

However, when a plurality of files are written to the SD storage 1110 at the same time in this way, an undesired phenomenon occurs in which the efficiency of continuous SD writing operation is reduced. More specifically, the SD write operation is based on a cluster, so when the F file X and the R file X are written to the SD storage 1110 at the same time (substantially), the actual behavior is that the F file X is. After being written to some clusters, the system switches to write the R file X to some clusters. The system keeps switching between the two files, as shown by numbers 1-8 in FIG. 11B. As a result, SD storage 1110 is unable to write continuously on the next adjacent cluster and instead "jumps" to a distant cluster to write another file. This phenomenon is sometimes called "random write" or "random jump" that reduces the SD write operation efficiency.

FIG. 12A is a schematic diagram of a storage device comprising an interleaved directory file and FAT according to an embodiment of the present invention, and FIG. 12B is a plurality of units consistent with the interleaving method according to the embodiment of the present invention. Shows how to store data in a cluster. In FIG. 12A, SD storage 1210 includes boot sectors 1220, FAT1230, directory entries 1240, and multiple data clusters 1250, which are also logically shown as 1260 in FIG. 12B.

To address the random write problem described with reference to FIGS. 11A and 11B, the cluster list of related video files stored in FAT1230 is formatted or configured to be interleaved. Importantly, cluster interleaving eliminates the random write phenomenon. This interleaved distribution method can be based on the bit rate composition of each video file in the cluster.

As an example, it is assumed that the bit rate ratio of the F file X and the R file X is 1: 1. In such cases, the FAT1230 is formatted or configured such that each contiguous cluster of F-file X and R-file X is equally interleaved with each other, resulting in stored data clusters as shown in multiple data clusters 1250 and 1260. ..

Of course, the bit rate ratio of the F file, X, and R file X can be expanded K times, and is generally represented by K: K (for example, K = 2). In such cases, the cluster list of the two video files can be interleaved as shown in FIGS. 13A and 13B, in that the interleaved cluster ratio is not limited from single cluster to single cluster. Sometimes referred to as a "fixed" interleaved directory file and FAT. Thus, FIG. 13A shows an SD storage 1310 containing a boot sector 1320, a FAT 1330, a directory entry 1340, and a plurality of data clusters 1350, which are also logically shown as 1360 in FIG. 13B and as shown in the figure. , Each F file X and R file X are assigned two clusters (K = 2) by an interleave method. Therefore, the interleaved FAT 1330 and data cluster 1350 cope with the random write phenomenon, even as the demand for additional clusters for each independent file increases.

FIG. 14A is a schematic representation of a storage device comprising another modified, interleaved FAT according to an embodiment of the invention, and FIG. 14B is another modification according to an embodiment of the invention. Shows how data is stored in multiple classes that match the interleaved method. FIG. 14A shows an SD storage 1410 containing a boot sector 1420, a FAT 1430, a directory entry 1440, and a plurality of data clusters 1450, which are also logically shown as 1460 in FIG. 14B. 14A and 14B show that the bitrate ratios of F-file X and R-file X do not necessarily have to have a 1: 1 ratio, but may instead have an unequal ratio such as 2: 1. .. Therefore, as shown in FAT1430, two clusters are assigned to the F file X for each cluster assigned to the R file X. Multiple data clusters 1450 and 1460 show this same allocation example.

From the above, it will be appreciated by those skilled in the art that unwanted random write phenomena may occur when storing multiple files for each file in separate but contiguously allocated clusters. Due to this phenomenon, the SD write performance deteriorates. The interleaving method described herein addresses this flaw. In addition, a cluster list interleave of each (video) file is configured during formatting according to the bitrate ratio between the video files. Once the files are recorded, the system switches SD writes between the files according to the bit rate ratio. And, significantly, SD random writes are avoided, resulting in continuous cluster writes that enable maintaining SD write efficiency.

As mentioned with respect to the embodiments of FIGS. 4-7, in the event of an unexpected power failure, the last written data can still be found due to the existence of the complete data link. Also, when looping recording, the old files are not deleted and only the file names are changed in the directory entries (430, 1140, 1240, 1340, 1440), thus improving shift efficiency. Both of these advantages remain in connection with the interleaving approach described herein.

Interleaving techniques can also use bit rate ratios between (video) files that are recorded at substantially the same time to configure allocations for each cluster. At the formatting stage, the cluster list is interleaved. When this set of files (eg, F file X and R file X) is recorded at substantially the same time, the system interlaces SD writes to different files according to the ratio of the number of clusters configured. This combination can achieve continuous cluster writes and maintain the efficiency of SD writes.

Finally, it should be noted that the cluster list interleaving mechanism described is not limited to only two video files (eg, F file X and R file X), but can also be applied to three or more interleaved video file clusters. sea bream.

Although the present invention has been described as an example and the above embodiments have been described, it should be understood that the present invention is not limited thereto. Conversely, it is intended to cover various modifications and similar arrangements and procedures, and therefore the claims of attachment are broadest to include all such modifications and similar arrangements and procedures. An interpretation should be given.

This application is a partial continuation of US Patent Application No. 15 / 709,813 filed on September 20, 2017, and benefits of Taiwan Patent Application No. 106121373 filed on June 27, 2017. Both subjects are incorporated herein by reference.

Claims (20)

It is a control method of the storage device of the drive recorder.
A step of configuring a directory entry for the storage device according to a predetermined directory entry stored in the storage unit, and
A step of configuring the FAT of the storage device according to a predetermined file allocation table (FAT) stored in the storage unit, and
It comprises the steps of controlling the controller to write data to the storage according to the directory entry and the FAT.
The entries in the FAT correspond to each predetermined cluster in the storage device, and each entry in the FAT is modified even after new data is written to each predetermined cluster in the storage device. Not done, control method. The control method of claim 1, wherein the data includes data from at least two files, wherein the FAT is configured to store the two files in an interleaved cluster. The at least two files are video files having the same bit rate, and the steps constituting the FAT in the storage device include assigning the same number of the predetermined clusters to each of the at least two files. The control method according to claim 2. The at least two files are video files having different bit rates from each other, and the steps constituting the FAT in the storage device are described in each of the at least two files according to the bit rates of the at least two files. The control method according to claim 2, comprising the step of allocating a predetermined cluster. The steps that make up the directory entry in the storage device are:
The control method of claim 1, comprising the step of configuring the file name corresponding to the file in the directory entry. The steps that make up the directory entry in the storage device are:
The control method of claim 5, comprising the step of configuring the start data cluster corresponding to the file in the directory entry. The steps that make up the FAT in the storage device are
The control method according to claim 6, wherein the FAT chain corresponding to the file is configured in the FAT. The step of controlling the controller to write data to the storage according to the directory entry and the FAT
In the directory entry, the step of updating the file name corresponding to the file, and
7. The control method of claim 7, comprising controlling the controller to write data to a data cluster in the storage configured for the file. The control method of claim 8, wherein in the directory entry, the starting data cluster corresponding to the file remains unchanged. The control method of claim 9, wherein in the FAT, the FAT chain corresponding to the file remains unchanged. It is a storage device control system
A storage unit that stores a given directory entry and a given file allocation table (FAT),
A controller that writes data to storage and
Including a processor, said processor
A step of configuring a directory entry for the storage device according to the predetermined directory entry.
A step of configuring the FAT of the storage device according to the predetermined FAT, and
Performing steps to control the controller to write data to the storage according to the directory entry and the FAT.
The entries in the FAT correspond to each predetermined cluster in the storage device, and each entry in the FAT is modified even after new data is written to each predetermined cluster in the storage device. A storage control system that remains untouched. 11. The storage device control system of claim 11, wherein the data includes data from at least two files, wherein the FAT is configured to store the two files in an interleaved cluster. The at least two files are video files having the same bit rate, and the steps constituting the FAT in the storage device include assigning the same number of predetermined clusters to each of the at least two files. Item 12. The storage device control system according to Item 12. The at least two files are video files having different bit rates from each other, and the steps constituting the FAT in the storage device are described in each of the at least two files according to the bit rates of the at least two files. 12. The storage control system of claim 12, comprising the step of allocating a predetermined cluster. The steps that make up the directory entry in the storage device are:
11. The storage device control system of claim 11, comprising the step of configuring the file name corresponding to the file in the directory entry. The steps that make up the directory entry in the storage device are:
15. The storage control system of claim 15, comprising the step of configuring the start data cluster corresponding to the file in the directory entry. The steps that make up the FAT in the storage device are
16. The storage device control system of claim 16, comprising configuring the FAT chain corresponding to the file into the FAT. The step of controlling the controller to write data to the storage according to the directory entry and the FAT
In the directory entry, the step of renaming the file corresponding to the file, and
17. The storage device control system of claim 17, comprising controlling the controller to write data to a data cluster in the storage device configured for the file. The storage control system of claim 18, wherein in the directory entry, the starting data cluster corresponding to the file remains unchanged. 19. The storage control system of claim 19, wherein in the FAT, the FAT chain corresponding to the file remains unchanged.

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