JP2006277812A - Data storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle data storage device capable of preventing the writing errors of a disk device and the damage such as the failure of the writing head of the disk device even when unexpected vibration occurs in the case of storing large capacity of data without interruption and performing the writing in the disk device at the time other than the vibration generation, thereby making a memory capacity relatively small and reducing device cost. <P>SOLUTION: This device is provided with a memory (1) for temporarily storing input data; a disk device (5) for receiving and storing data stored in the memory; a vibration detection means (9) for detecting vibration of a predetermined value or more generated in a vehicle; and a control means (11) for inhibiting the transmission of data from the memory to the disk device until there is no more influence of vibration when the vibration is detected by the vibration detection means (9). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a data storage device (vehicle data storage device) mounted on a vehicle.

  As in-vehicle data storage devices, it is necessary to increase the speed of access to storage media and increase the density and capacity, and in-vehicle storage devices using built-in HDDs (hard disk devices) are rapidly increasing.

  However, as the characteristics of HDD, especially those with higher access speed and higher density and larger capacity are more susceptible to disturbances due to vibrations, etc., for example, when the magnetic head inside the HDD is in contact with the disk, When the vehicle is subjected to vibration associated with movement, there is a problem that a data access error or a failure is likely to occur.

  Up to now, various methods have been proposed for vibration countermeasures for in-vehicle HDDs. In one of them, the input data is temporarily stored in the first storage means (for example, a semiconductor memory) while the vehicle is moving, and the second storage means (for example, the first storage means when the vehicle is stopped). Data is transferred to and stored in the HDD (see, for example, Patent Document 1).

  In another method, in a hybrid storage having a disk device and a non-volatile semiconductor memory, a storage medium to be read and written according to a user specification or an operating state such as temperature, vibration / impact, noise, etc. , Select either disk device or non-volatile semiconductor memory to switch, maintain consistency of data to be read / written, continue processing executed by information processing device, and store the switched The medium is accessed (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 2003-167772 (pages 1 to 5, FIG. 1) JP 2004-164193 A (pages 1 to 28, FIG. 1)

  In the in-vehicle data storage device described in the above-mentioned Patent Document 1, when it is desired to store a large amount of data, such as recording a digital terrestrial broadcast program, the second storage device is used as long as the vehicle does not stop. Since the data is not transferred to the storage means, there is a problem that it is necessary to use a large-capacity memory as the first storage means used for the purpose of temporarily storing the input data.

  Further, in the conventional hybrid storage described in Patent Document 2 and an information processing apparatus using the same, if it is desired to store a large amount of data, such as recording a digital terrestrial broadcast program, it is a relatively expensive large storage. There was a problem that a nonvolatile memory with a capacity was necessary.

  The present invention has been made to solve the above-described problems, and is a data storage device mounted on a vehicle, in which a memory that temporarily stores input data and a data storage device that stores the data stored in the memory. The disk device that receives and stores the data, and the transfer of data from the memory to the disk device is prohibited until the influence of the vibration is reduced after the vibration is generated in the vehicle, and after the influence of the vibration is reduced There is provided a data storage device comprising control means for transferring data from the memory to the disk device.

  As an effect of the present invention, when a large amount of data such as digital terrestrial broadcasting is stored without interruption when the vehicle is running, even if sudden vibration occurs, a disk device write error occurs, or the disk device write head ( For example, writing to the disk device is performed without causing a failure such as a failure of the magnetic head of the HDD, and at times other than the occurrence of vibration, so the capacity of the memory (for example, volatile memory) is large. It is relatively small and the cost of the apparatus can be reduced.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

Embodiment 1 FIG.
FIG. 1 shows the configuration of an in-vehicle data storage device according to Embodiment 1 of the present invention. FIG. 2 shows an installation position of each member inside the vehicle.

  The illustrated in-vehicle data storage device is installed inside the vehicle 14 as shown in FIG. 2, and is composed of a volatile memory for temporarily storing input necessary data (data to be stored). A data storage delay buffer 1, a buffer controller 2, a vibration detector 3, an HDD controller 4, and a hard disk device (HDD) 5 for storing data.

  The buffer controller 2 reads from the read pointer generator 7 for reading data stored in the data storage delay buffer 1, the data access controller 8 that controls the read pointer generator 7, and the data storage delay buffer 1. A data holding latch 6 is provided for temporarily holding the processed data.

  The HDD controller 4 controls the HDD 5 in order to store the data output from the data holding latch 6 in the HDD 5.

  The vibration detector 3 absorbs vibration during vehicle travel, and a first vibration sensor (first vibration detection means) 9 installed in the vicinity of the axle 16 in order to detect vibration during vehicle travel early. Further, the vibration from the second vibration sensor (second vibration detecting means) 10 installed on the damper 12 (FIG. 2) for delaying the vibration, the first vibration sensor 9 and the second vibration sensor 10 A data access controller 8 and an access control signal generator 11 for controlling the HDD controller 4 are provided based on the information.

  Among the above, the data storage delay buffer 1, the buffer controller 2, the HDD controller 4, the HDD 5, and the access control signal generator 11 constitute an in-vehicle data storage device body 13 installed on the damper 12. .

  As will be described in detail below, the access control signal generator 11 uses the first vibration sensor when sudden vibrations occur due to vehicle running when the necessary data input without interruption is stored in the HDD 5. 9 and the vibration information from the second vibration sensor 10, the period that adversely affects the HDD 5 is detected, and the read pointer generator 7 and the HDD controller 4 are controlled. Control is performed so as to temporarily stop the process of writing the temporarily stored data in the HDD 5, and after the adverse effect of vibration ends, the process of writing the data temporarily stored in the data storage delay buffer 1 is resumed.

  As shown in FIG. 2, the first vibration sensor 9 is arranged in the vicinity of the axle 16 inside the vehicle 14, and the second vibration sensor 10 is a damper 12 arranged for vibration absorption and delay. It is arranged above and in the vicinity of the HDD 5.

  FIG. 3 shows vibration detection signals V1 and V2 generated by detecting vibrations during vehicle travel by the first vibration sensor 9 and the second vibration sensor 10, and access based on these vibration detection signals V1 and V2. The temporal relationship of the HDD access prohibition signal WP generated by the control signal generator 11 is shown on the time axis.

In FIG. 1, a data flow until necessary data to be input (data to be stored) is stored in the HDD 5 will be described.
Necessary data from the previous stage is input at a constant rate to the data storage delay buffer 1 composed of a volatile memory, and is continuously stored without interruption. Thereafter, the read address RA and the read enable signal RE are output from the read pointer generator 7 under the control of the read signal RD from the data access controller 8, and the necessary data stored in the data storage delay buffer 1 is high speed. Then, the data is read out in the burst access mode and further input to the data holding latch 6 in the subsequent stage.
The data holding latch 6 is necessary to temporarily hold data until preparation for writing to the HDD 5 in the subsequent stage is completed (for example, until the write head moves to the head of the sector where data is to be written). A minimum storage capacity is built in, and the data output from the data holding latch 6 is stored in the HDD 5 via the HDD controller 4.

  Hereinafter, an operation in the case where vibration or the like during traveling of the vehicle occurs in the process in which the input necessary data is stored in the HDD 5 will be described with reference to FIGS.

  Vibration is generated in the axle 16 of the vehicle 14, and the vibration is detected by the first vibration sensor 9 disposed in the vicinity of the axle 16, and the vibration detection signal V1 is output at time “t1” shown in FIG. When the amplitude is equal to or greater than the first threshold value), the HDD access prohibition signal WP output from the access control signal generator 11 is asserted and input to the data access controller 8. The first threshold takes into consideration the magnitude of vibration that causes a write error in the HDD 5, the relationship between the magnitude of vibration at the position of the first sensor 9 and the magnitude of vibration in the HDD 5, the sensitivity of the first sensor 9, and the like. When the first sensor 9 detects a vibration of a certain value or more, if the possibility that a write error occurs in the HDD 5 is so high that it cannot be ignored, the certain value is the first threshold value. It is determined.

  When the HDD access prohibition signal WP is asserted, the data access controller 8 disables the data read signal RD, and the read pointer generator 7 negates the read enable signal RE based on this, and the data storage delay buffer 1 Stop data output from. At the same time, the access control signal generator 11 asserts the HDD access prohibition signal WP to stop the HDD controller 4 from writing data to the HDD 5.

The vibration detection signal V2 from the second vibration sensor 10 mounted on the damper 12 is generated while the stop state is maintained, and then stops (after the amplitude becomes equal to or greater than the second threshold value, the third A predetermined time (slight delay time) elapses after the time becomes less than the threshold or less than the third threshold (time “t2”), and information indicating this is input to the access control signal generator 11. The HDD access prohibition signal WP is negated.
The second threshold value is the magnitude of vibration that causes a write error in the HDD 5, the relationship between the magnitude of vibration at the position of the second vibration sensor 10 and the magnitude of vibration in the HDD 5, and the sensitivity of the second vibration sensor 10. If a vibration greater than a certain value of the second vibration sensor 10 is detected, the possibility that a write error will occur in the HDD 5 is so high that it cannot be ignored. A threshold value of 2 is set. The third threshold value is set to a value equal to or smaller than the second threshold value. The reason why the third threshold value is set to a value smaller than the second threshold value is to prevent repeated switching of the determination result (and change of processing content based on it) due to a minute fluctuation in amplitude. The predetermined time is determined in consideration of the time until the possibility of a write error in the HDD 5 due to vibration becomes sufficiently low after the amplitude becomes less than the third threshold. If the predetermined time is sufficiently long, the third threshold value may be the same as the second threshold value. This is because if the predetermined time is made sufficiently long, even if the third threshold value is the same as the second threshold value, the effect of preventing the processing content from being repeatedly switched due to a small amplitude can be obtained.

  When the HDD access prohibition signal WP is negated, the data access controller 8 enables the data read signal RD, and the read pointer generator 7 asserts the read enable signal RE based on this signal read signal RD. Resume data reading. At the same time, the HDD controller 4 is instructed to resume data writing to the HDD 5.

  Further, for data that is not read from the data storage delay buffer 1 during the period (Δt) during which the HDD access prohibition signal WP is asserted and is not stored in the HDD 5, the HDD access prohibition signal WP is negated. In addition, before the internal storage data of the data storage delay buffer 1 is overwritten with the subsequent data, the data access controller 8 issues a data read request to the read pointer generator 7, and the data storage Data read from the delay buffer 1 is stored in the HDD 5 via the data holding latch 6 and the HDD controller 4.

  As described above, according to the first embodiment of the present invention, the vibration generated when the vehicle travels is mounted on the first vibration sensor 9 and the damper 12 disposed in the vicinity of the axle 16 and in the vicinity of the HDD 5. By detecting both of the second vibration sensors 10 arranged, before the HDD 5 main body is affected by vibration, writing to the HDD 5 is stopped in advance and the second vibration sensor 10 arranged near the HDD 5 is stopped. It is possible to continue to stop writing to the HDD 5 until it is detected from the output of the vibration sensor 10 that the influence of vibration has been lost. Also, regarding data for a period during which writing to the HDD 5 was stopped, the HDD 5 Since it is configured to read from the data storage delay buffer 1 and write to the HDD 5 during a period in which there is no influence of vibration on the vehicle, the digital terrestrial When storing large volumes of data without interruption, even if sudden vibrations occur, it is stable without causing a failure such as a write error to the HDD 5 or a failure of the magnetic head of the HDD 5 Data can be stored. In addition, even when the vehicle is running, when vibration does not occur, data is written to the HDD 5, so that the data storage delay buffer 1 may be a relatively small one. The cost of the data storage device can be reduced.

Embodiment 2. FIG.
FIG. 4 shows an in-vehicle data storage device according to the second embodiment. 4, the same reference numerals as those in FIG. 1 denote the same or similar members. The data storage device shown in FIG. 4 is generally the same as the data storage device shown in FIG. 1, but differs in the following respects. That is, the second vibration sensor 10 of FIG. 1 is not provided, and a termination time estimator 15 is provided instead.

The end time estimator 15 stores the damper constant of the damper 12 in advance. When vibration is detected by the first vibration sensor 9, the end time estimator 15 estimates the time when the vibration of the HDD 5 due to the detected vibration ends. The pulse PT is generated at the estimated end time. The time from when the vibration is detected by the first vibration sensor 9 to the time when the vibration in the HDD 5 ends is longer as the energy (amplitude, duration) of the vibration detected by the first vibration sensor 9 is larger. Taking this into account, the time until the vibration in the HDD ends is estimated.
The access control signal generator 11 asserts the HDD access prohibition signal WP after the first vibration sensor 9 detects vibration until the pulse PT is generated.

  FIG. 5 shows a vibration detection signal V1 generated by detecting vibrations during vehicle travel by the first vibration sensor 9, a pulse PT generated by the end time estimator 15, and an access control signal generator based on these signals. 11 shows the temporal relationship of the HDD access prohibition signal WP generated at 11 on the time axis.

  Hereinafter, the operation when vibration or the like occurs when the vehicle travels will be described with reference to FIGS. Vibration is generated on the axle 16 of the vehicle 14, and the vibration is detected by the first vibration sensor 9 disposed in the vicinity of the axle 16, and the vibration detection signal V1 is output at time “t1” shown in FIG. When the amplitude is equal to or greater than the first threshold value), the access control signal generator 11 asserts the HDD access prohibition signal WP and inputs it to the data access controller 8. When the HDD access prohibition signal WP is asserted, the data access controller 8 disables the data read signal RD, and the read pointer generator 7 negates the read enable signal RE based on this, and the data storage delay buffer 1 Stop data output from. At the same time, the access control signal generator 11 asserts the HDD access prohibition signal WP to stop the HDD controller 4 from writing data to the HDD 5.

  When the time “t3” is reached while maintaining this stop state, a pulse PT indicating that the time until the end of vibration in the HDD (estimated time) has elapsed is generated from the end time estimator 15. When this pulse PT is generated, the HDD access prohibition signal WP output from the access control signal generator 11 is negated.

  When the HDD access prohibition signal WP is negated, the data access controller 8 enables the data read signal RD, and the read pointer generator 7 asserts the read enable signal RE based on this signal read signal RD. Resume data reading. At the same time, the HDD controller 4 is instructed to resume data writing to the HDD 5.

  Further, for data that is not read from the data storage delay buffer 1 during the period (Δt) during which the HDD access prohibition signal WP is asserted and is not stored in the HDD 5, the HDD access prohibition signal WP is negated, and Before the internal storage data of the data storage delay buffer 1 is overwritten with the subsequent data, a data read request for the corresponding part is generated from the data access controller 8 to the read pointer generator 7, and the data storage delay Data read from the buffer 1 is stored in the HDD 5 via the data holding latch 6 and the HDD controller 4.

  As described above, according to the second embodiment of the present invention, the vibration generated when the vehicle travels is detected by the first vibration sensor 9 disposed in the vicinity of the axle 16, and the end time estimator 15 in the HDD 5 is detected. By estimating the vibration end time, writing to the HDD 5 is stopped in advance before the main body of the HDD 5 is affected by the vibration, and writing to the HDD 5 is continuously stopped until the influence of the vibration is eliminated. In addition, data for a period during which writing to the HDD 5 was stopped is read from the data storage delay buffer 1 and written to the HDD 5 during a period when there is no influence of vibration on the HDD 5. Therefore, even when sudden vibration occurs when large-capacity data such as terrestrial digital broadcasting is stored without interruption when the vehicle is running, Or cause a write error without causing failures such as by failure of HDD5 magnetic head can store stably data. In addition, even when the vehicle is running, when vibration does not occur, data is written to the HDD 5, so that the data storage delay buffer 1 may be a relatively small one. The cost of the data storage device can be reduced.

  Further, since the second vibration sensor 10 can be omitted as compared with the first embodiment, the cost of the data storage device can be further reduced.

  As an application example of the present invention, the present invention can be applied to an in-vehicle data storage device using an HDD including a Japanese terrestrial digital broadcast receiver.

1 is a block diagram of an in-vehicle data storage device according to Embodiment 1 of the present invention. 2 is a layout diagram showing a positional relationship among a vibration sensor, a damper, and an HDD inside a vehicle. It is a figure which shows the output from a 1st vibration sensor and a 2nd vibration sensor, and a HDD access prohibition signal. It is a block diagram of the vehicle-mounted data storage device by Embodiment 2 of this invention. It is a figure which shows the output of a 1st vibration sensor and an end time estimator, and a HDD access prohibition signal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Data storage delay buffer (volatile memory), 2 Buffer controller, 3 Vibration detector, 4 HDD controller, 5 HDD, 6 Data holding latch, 7 Read pointer generator, 8 Data access controller, 9 1st vibration Sensor, 10 second vibration sensor, 11 access control signal generator, 12 damper, 13 data storage device, 14 vehicle, 15 end time estimator, 16 axle.

Claims (6)

A data storage device mounted on a vehicle,
A memory for temporarily storing the input data;
A disk device for receiving and storing data stored in the memory;
Data transfer from the memory to the disk device is prohibited until the influence of the vibration is reduced after the vibration is generated in the vehicle. After the influence of the vibration is reduced, data transfer from the memory to the disk device is prohibited. A data storage device comprising: control means for performing transfer. A first vibration detecting means for detecting vibration generated in the vehicle;
The control means prohibits data transfer from the memory to the disk device until the influence of the vibration is reduced after vibration is detected by the first vibration detecting means. The data storage device described in 1.   The data storage device according to claim 1, wherein the disk device is installed on a damper that absorbs vibration during vehicle travel and delays the vibration. The disk device is installed on a damper that absorbs vibration during vehicle travel and delays vibration,
The first vibration detecting means is disposed in the vicinity of the axle of the vehicle and detects the occurrence of vibrations of a predetermined value or more;
A second vibration detecting means installed on the damper for detecting occurrence and termination of vibration;
The control means includes
Inhibiting the transfer of data from the memory to the disk device from when the occurrence of vibration is detected by the first vibration detection means until the end of vibration is detected by the second vibration detection means. The data storage device according to claim 2. The first vibration detecting means is disposed in the vicinity of the axle of the vehicle and detects the occurrence of vibrations of a predetermined value or more;
When a vibration is detected by the first vibration detection means, and an end time estimation means for estimating a time at which the vibration of the optical disc due to the vibration ends,
The control means prohibits the transfer of data from the memory to the disk device until the end time estimated by the end time estimation means after the occurrence of vibration is detected by the first vibration detection means. The data storage device according to claim 2 or 3, wherein   6. The data storage device according to claim 1, wherein the memory is a volatile memory.

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