JP5741511B2 - Freeze frame data storage system - Google Patents

Description

  The present invention relates to a system for storing freeze frame data representing a state value at the time of occurrence of an abnormality.

  In Patent Document 1, etc., when a diagnosis device mounted on a vehicle detects the occurrence of an abnormality in the vehicle, various state values at the time of occurrence of the abnormality are stored as freeze frame data (hereinafter referred to as FF data). It is disclosed. As specific examples of the state value, dozens of state values such as engine speed, vehicle speed, accelerator pedal depression amount, brake pedal depression amount, engine coolant temperature, intake air temperature, exhaust temperature, steering wheel operation angle, shift range, etc. Is mentioned. Such FF data is effective in analyzing the cause of occurrence of abnormality.

JP 2004-232498 A

  Now, each of various control ECUs (slave ECUs) such as an engine control ECU and a transmission control ECU, and a master ECU that comprehensively manages these slave ECUs form a network via a communication bus. The above-described sensors for detecting the state value are connected to each slave ECU, and the slave ECU transmits the state value data (state data) input from the sensor to the master ECU at a predetermined cycle. . When the master ECU detects the occurrence of an abnormality, the master ECU stores the state data at that time in a backup memory, a nonvolatile memory, or the like, and leaves it as the FF data described above.

  In this way, by centrally managing the FF data with the master ECU, a plurality of types of state values included in the FF data can be synchronized. Further, the vehicle repair worker can acquire all the FF data only by communicating with the master ECU.

  Here, as the cycle of transmitting the status data from the slave ECU to the master ECU is shortened, the status data transmitted at a timing closer to the time of occurrence of the abnormality can be left as FF data. The reliability of the FF data can be improved. However, contrary to this, since the amount of data flowing through the communication bus increases, the load on the communication bus increases.

  The present invention has been made in view of the above problems, and an object thereof is to provide a freeze frame data storage system that achieves both improvement in reliability of freeze frame data and reduction in communication bus load.

In the first invention for achieving the above object, a slave device that is mounted on a vehicle and sequentially acquires a state value representing the state of the vehicle, and a master that is mounted on the vehicle and can communicate with the slave device via a communication bus. And the slave device has transmission means for transmitting state data representing the state value and change rate data capable of specifying the change rate of the state value to the communication bus in a predetermined cycle. The master device, when detecting the occurrence of an abnormality, based on the state data and the change rate data transmitted from the slave device, an estimation unit that estimates the state value at the time of occurrence of the abnormality, and the estimation unit the data representing the estimated state value, possess a storage means for storing in the storage device as the freeze frame data (FF data), the said estimation means, transmitted at a predetermined period Among the number of status data, the status data transmitted immediately before the occurrence of the abnormality is compared with the transmission timing of the status data transmitted immediately after the occurrence of the abnormality, and the status data transmitted at a time close to the time of occurrence of the abnormality And the change rate data thereof are used to estimate the state value at the time of occurrence of the abnormality (see FIGS . 1 and 6 ).

  In the above invention, since the state value at the time of occurrence of the abnormality is estimated based on the state data and the change rate data transmitted at the time of occurrence of the abnormality, the abnormality is detected without shortening the predetermined cycle for transmitting the state data to the communication bus. The state value at the time of occurrence can be estimated with high accuracy. Therefore, since highly accurate FF data can be left in the storage device, it is possible to achieve both improvement in reliability of FF data and reduction in communication bus load.

  The inventor linearly interpolates the state value transmitted immediately before the occurrence of the abnormality and the state value transmitted immediately after the occurrence of the abnormality to estimate the state value at the time of occurrence of the abnormality, and the estimated value is converted to FF data. Considered to leave as. However, when the transmission cycle is lengthened in order to reduce the load on the communication bus, the above-described linear interpolation has poor estimation accuracy and does not improve the reliability of the FF data. On the other hand, in the said invention estimated using a change rate, it can estimate with high precision compared with the case where it estimates by linear interpolation.

  In the second invention for achieving the above object, the slave device is mounted on a vehicle and sequentially acquires state values representing the state of the vehicle, and is mounted on the vehicle and can communicate with the slave device via a communication bus. A master device and an external device that can communicate with the master device, and the slave device can specify state data representing the state value and a rate of change of the state value. Transmission means for transmitting the change rate data to the communication bus at a predetermined cycle, and the master device includes a freeze frame that includes at least the state data and the change rate data when an abnormality is detected. A storage unit for storing an abnormality as data (FF data) in the storage device, and the external device stores the state value at the time of occurrence of the abnormality based on the freeze frame data. Characterized in that it has an estimated means constant for (see FIG. 7).

  According to the above invention, when a repair worker connects an external device to the master device for a vehicle that has been transported to a repair site due to the occurrence of an abnormality, the external device acquires FF data from the master device and an abnormality occurs. The state value at the time can be estimated. In this estimation, since the state value at the time of occurrence of the abnormality is estimated based on the state data and the change rate data transmitted when the abnormality occurrence is detected, the predetermined period for transmitting the state data to the communication bus is not shortened. The state value at the time of occurrence of abnormality can be estimated with high accuracy. Therefore, since highly accurate FF data can be left in the storage device, it is possible to achieve both improvement in reliability of FF data and reduction in communication bus load.

1 is a configuration diagram of a freeze frame data storage system according to a first embodiment of the present invention. FIG. The figure which shows the content of the data transmitted between ECU in 1st Embodiment. The figure which shows the change of a state value, and the state data and change rate data which were transmitted to the communication bus in 1st Embodiment. The flowchart of the process implemented by master ECU in 1st Embodiment. The flowchart of the process implemented by master ECU in 1st Embodiment. The figure explaining the method of estimating the state value in abnormality occurrence time in 1st Embodiment. The block diagram of the freeze frame data storage system concerning 2nd Embodiment of this invention. A figure explaining change rate data in a 3rd embodiment of the present invention.

  Embodiments of a freeze frame data storage system according to the present invention will be described below with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are denoted by the same reference numerals in the drawings, and the description of the same reference numerals is used.

(First embodiment)
As shown in FIG. 1, a vehicle V is equipped with a plurality of various electronic control devices (slave ECUs 10A to 10C) and a master ECU 40 that collectively manages these slave ECUs 10A to 10C. The slave ECUs 10 </ b> A to 10 </ b> C and the master ECU 40 construct a network via the communication bus 30. This network is a local area network using a protocol such as CAN.

  Each of the slave ECUs 10A to 10C (slave devices) is connected to various sensors 20A, 20B, and 20C to perform input processing and the like, and a communication unit 12 that performs data transmission and reception processing to the communication bus 30. And a known microcomputer (arithmetic unit 13) including a CPU, a RAM, a ROM, and the like.

  For example, in the input / output unit 11 of the slave ECU 10A, detection values (state values) such as an engine speed, a vehicle speed, an accelerator pedal depression amount, a brake pedal depression amount, an engine coolant temperature, an intake air temperature, and an exhaust temperature are received from various sensors 20A. Entered. And the calculating part 13 of slave ECU10A controls the action | operation of a vehicle-mounted engine based on these detection values.

  Further, for example, the detection value (state value) of the sensor 20B that detects the handle operating angle is input from the sensor 20B to the input / output unit 11 of the slave ECU 10B. And the calculating part 13 of slave ECU10B controls an electric steering apparatus based on the detected value of the sensor 20B.

  Further, for example, the input / output unit 11 of the slave ECU 10C receives a detection value (state value) of the sensor 20C that detects the shift range (shift stage) operated by the vehicle driver from the sensor 20C. Then, the calculation unit 13 of the slave ECU 10C controls the operation of the automatic transmission based on the detection value of the sensor 20C.

  Incidentally, these various detection values (state values) are values calculated by the ECUs 10A, 10B, and 10C based on signals output from the respective sensors 20A, 20B, and 20C. For example, the engine speed (state value) described above is a value calculated by the slave ECU 10A based on the pulse signal output from the crank angle sensor (sensor 20A).

  Furthermore, each calculating part 13 of slave ECU10A-10C exhibits the function as the transmission period change means 13a, the data preparation means 13b, the data transmission means 13c, and the data change amount calculation means 13d which are demonstrated below.

  That is, the data creation unit 13b extracts and creates data (state data) to be transmitted to the communication bus 30 from detection values (state values) sequentially input from the sensors 20A to 20C. The data change amount calculation means 13d calculates the change amount (change rate data) of the extracted state data. The data transmission unit 13c outputs the change rate data and the state data to the 12 communication unit and transmits them to the communication bus 30 (see FIG. 2B). The transmission cycle changing means 13a changes the cycle (predetermined cycle) for transmitting the change rate data and the state data to the communication bus 30 based on a command from the master ECU 40.

  The data transmitted in this way is received by other slave ECUs and used for controlling the engine, steering device and automatic transmission, and also received by the master ECU 40.

  The master ECU includes a communication unit 41 that performs processing of data transmission and reception to the communication bus 30, a non-volatile memory 42 such as an EEPROM (registered trademark), and a known microcomputer (CPU, RAM, ROM, etc.). And an arithmetic unit 45). In addition, a connector 44 that connects to the external device 50 is connected to the master ECU.

  The arithmetic unit 45 of the master ECU exhibits functions as data receiving means 45a, abnormality storage means 45b, periodic storage means 45c, estimation means 45d, transmission cycle setting means 45e, and data transmission means 45f described below.

  That is, the data receiving unit 45a causes the communication unit 41 to sequentially receive a plurality of types of state data and change rate data transmitted from the slave ECUs 10A to 10C to the communication bus 30. When the abnormality storage means 45b detects that an abnormality has occurred in any of the vehicles V, it stores the received state data and change rate data in the EEPROM 42 as freeze frame data (FF data).

  The periodic storage unit 45c periodically stores the received state data and change rate data in the EEPROM 42 at predetermined time intervals. However, every time new data is stored, the oldest data is deleted. As a result, the amount stored in the EEPROM 42 by the periodic storage means 45c is always constant. For example, the past 30 pieces of data from the latest data to be periodically stored are stored in the EEPROM 42 as FF data, and no more is stored. The estimation means 45d will be described in detail later.

  The transmission cycle setting unit 45e sets the above-described predetermined cycle (cycle for transmitting data to the communication bus 30) for each of the slave ECUs 10A to 10C. For example, when the state value changes rapidly in a short time, the predetermined cycle is set short, and when the change is slow, the predetermined cycle is set long. Also, the predetermined period is set to a different value depending on the type of the state value. For example, since the change in the engine speed changes abruptly in a short time compared to the change in the engine coolant temperature, among the state values, the engine speed is set shorter than the water temperature. The data transmitting unit 45f transmits the set predetermined cycle from the communication unit 41 to each of the slave ECUs 10A to 10C (see FIG. 2A).

  FIG. 3 is a diagram showing an aspect in the case where the engine speed (state value) is transmitted from the slave ECU 10A, and the solid line in the figure indicates a change in the value of the actual engine speed. However, this is a change in the rotation speed when an abnormality occurs at the time Ta. Specific examples of the abnormality include disconnection of signal lines that transmit various sensor signals, misfires in the engine, and abnormalities that lead to the operation of safety devices such as airbags.

  The dotted line in the figure indicates the minimum time (reference time) of the cycle for transmission to the communication bus 30. In the example of the figure, the reference time is set to 32 milliseconds. Circles indicated by reference signs D1 to D20 in the figure indicate state data transmitted to the communication bus 30. In the example of FIG. 3, the master ECU 40 requests to increase the transmission cycle at time t11 and time t41, and requests to decrease at time t32.

  Each of the signs DΔ1 to DΔ20 in the figure is data (change rate data) that can specify the change rate of the state data D1 to D20. Specifically, the data change amount calculation unit 13d calculates the difference (change amount) between the state data transmitted this time and the state data one reference time before the data, and changes the calculated change amount. It is set as rate data DΔ1 to DΔ20 and transmitted together with the state data D1 to D20.

  4 and 5 are flowcharts showing a processing procedure executed by the calculation unit 45 of the master ECU 40. Note that these processes are repeated in a predetermined time cycle, and the predetermined time is preferably equal to or shorter than the reference time shown in FIG. The predetermined time is preferably synchronized with a reference time or with a value that is an integral multiple of the reference time.

  First, in step S10 of FIG. 4, it is determined whether or not it is an abnormality detection event. For example, when the abnormality detection unit included in the slave ECUs 10A to 10C detects an abnormality, the master ECU 40 detects the abnormality by transmitting the fact from the slave ECUs 10A to 10C to the master ECU 40. However, the master ECU 40 itself may include an abnormality detection means to detect an abnormality.

  When it is determined that an abnormality detection event has occurred (S10: YES), in the subsequent step S11, the state data D10 transmitted immediately before the detection time ta is stored in the EEPROM 42 as FF data. In the subsequent step S12, the FF storage history flag is set to ON.

  Next, in step S20 of FIG. 5, it is determined whether or not it is time to receive data from the slave ECUs 10A to 10C. If it says in the example of FIG. 3, it will be determined whether it is a timing which receives status data D1-D20. If it is determined that the data is being received (S20: YES), if the FF storage history flag is set to ON (S21: YES), in the subsequent step S22, the current state data and the previous state data are The transmission timings are compared, and the state data transmitted at the timing close to the abnormality occurrence time ta is selected.

  For example, in the example of FIG. 3 and FIG. 6A, the transmission time t32 of the current value D11 immediately after the abnormality detection is greater than the transmission time t31 of the previous value D10 at the abnormality occurrence time ta or abnormality occurrence detection time. Since it is close, the current value D11 is selected. On the other hand, in the example of FIG. 6B, the transmission time t31 of the previous value D10 immediately before the abnormality detection is closer to the abnormality occurrence time ta or the abnormality detection time than the transmission time t32 of the current value D11. The previous value D10 is selected.

  In the subsequent step S23, the state value Da at the time of occurrence of abnormality ta is estimated based on the selected state data and its change rate data. This estimation process is performed by the estimation means 45d shown in FIG. In the example of FIG. 6A, it is assumed that the state value Da exists on a straight line passing through the current value D11 with the gradient of the change rate data DΔ11. In the example of FIG. 6B, it is assumed that the state value Da exists on the straight line passing through the previous value D10 with the gradient of the change rate data DΔ10.

  In the following step S24, the FF data temporarily stored in the EEPROM 42 in step S11 of FIG. 4 is updated to the state value Da estimated in step S23, and the FF storage history flag is set to OFF in the next step S25. .

  In the following step S26, the change amount (change rate) of the current state value with respect to the previous state value is calculated regardless of whether or not an abnormality has been detected. If the calculated value is less than a predetermined value, step S27 is performed. Then, the transmission cycle setting means 45e sets a predetermined cycle so as to increase the transmission cycle, and makes a change request to the corresponding slave ECU. On the other hand, if the calculated value is greater than or equal to the predetermined value, the process proceeds to step S28, where the transmission cycle setting means 45e sets the predetermined cycle so as to shorten the transmission cycle, and issues a change request to the corresponding slave ECU.

  Incidentally, the storage of the FF data in step S11 of FIG. 4 is performed once at the time of the abnormality detection event, and a plurality of data (engine speed and water temperature) are stored in the one process. On the other hand, the change of the transmission cycle in steps S27 and S28 in FIG. 5 is performed at each data reception timing.

  Further, as described above, the regular storage unit 45c of the master ECU 40 performs the regular storage process described below separately from the processes of FIGS. That is, state data and change rate data transmitted at a predetermined cycle (periodic storage interval) are periodically stored in the EEPROM 42 at a predetermined interval. The regular storage interval is desirably set to a time (for example, 256 milliseconds) longer than the reference time shown in FIG.

  For example, in the case of FIG. 3, the data is periodically stored in the EEPROM 42 at timings t10, t20... T60, and the past data is sequentially deleted. For example, the timings t10 and t40 of t10 and t40 coincide with the data transmission timing, so that the data D1 and D13 transmitted at that time are stored as one of the latest time-series data.

  The timing of t20 is an intermediate timing at which the data D7 and D8 are transmitted before and after the timing. In this case, the state value at time t20 is estimated using any of the state data D7 and D8 and the change rate data DΔ7 and DΔ8, and the estimated value is stored as one of the latest time series data.

  Similarly, since the timing of t30 is in the middle of the timing at which the data D9 and D10 are transmitted before and after that timing, any of the state data D9 and D10 and the change rate data DΔ9 and DΔ10 are used to obtain the time t30. Is estimated, and the estimated value is stored as one of the latest time series data.

  Regarding the timing of t50, among the timings at which the data D18 and D19 are transmitted before and after the timing, the timing of the data D19 transmitted immediately after t50 is closer to t50. In this case, the state value at the time t50 is estimated using the data D19 and the change rate data DΔ19 transmitted at the near time, and the estimated value is stored as one of the latest time series data.

  For example, when only the past three pieces of data are stored as the latest time series data, the data D13 is stored at the time t40, and the data D1 stored at the time t10 is deleted, and t20, t30, t40 are stored. The latest time series data at the three points are stored as FF data.

  Further, the arithmetic unit 45 of the master ECU 40 causes the EEPROM 42 to store, as FF data, data of a period including at least the abnormality occurrence time ta (abnormal time series data) among the time series data described above. The abnormal time series data may be the latest time series data described above. In other words, if no abnormality occurs, the past data is deleted sequentially in the latest time series data. However, if an abnormality occurs, the latest time series data at the time of the abnormality is deleted without being deleted. Store as time-series data.

  Therefore, when the occurrence of an abnormality is detected in the present embodiment, the estimated value Da of the state value at the time of occurrence of the abnormality, the abnormal time series data, and the latest time series data are stored in the EEPROM 42 as FF data. Therefore, the vehicle repair worker connects the external device 50 to the master ECU 40, acquires the above-described three types of FF data, identifies the location where the abnormality occurs, analyzes the cause of the abnormality, and the like based on the acquired FF data. Can be done.

  According to the embodiment described in detail above, the following effects are exhibited.

  Based on the state data D11 and the change rate data DΔ11, the state value Da at the time of occurrence of the abnormality is estimated. Therefore, as shown by the one-dot chain line in FIG. 3, the state values D10 and D11 transmitted before and after the occurrence of the abnormality are linearly interpolated to estimate the state value at the point of occurrence of the abnormality ta, compared with the estimated value Dx. The estimation accuracy can be improved. Accordingly, the state value at the time of occurrence of the abnormality can be estimated with high accuracy without shortening the predetermined cycle for transmitting the state data to the communication bus 30, so that the reliability of the FF data is improved and the load on the communication bus 30 is reduced. Can be achieved.

  -The rate of change data is smaller than the status data. Therefore, for example, instead of transmitting change rate data, the transmission frequency is the same, but the size of data to be transmitted is reduced compared to the case where the transmission cycle is shortened to half and the state data is transmitted twice. it can. Therefore, the amount of data flowing through the communication bus 30 can be reduced, and the load on the communication bus 30 can be reduced.

  In addition to the estimated value Da of the state value at the time of occurrence of the abnormality, the abnormality time-series data is also left as FF data, so that the repair worker can grasp the change of the state value in the vicinity of the abnormality occurrence time. Therefore, it is possible to improve work efficiency such as specifying an abnormality occurrence location and analyzing the cause of the abnormality.

  -In addition to the estimated value Da of the state value at the time of occurrence of the abnormality, the latest time series data is also left as FF data, so the repair worker can see the change in the state value in the vicinity when the vehicle is brought into the repair shop. I can grasp. Therefore, it is possible to improve work efficiency such as specifying an abnormality occurrence location and analyzing the cause of the abnormality.

  -Since the above estimation is performed using the state data transmitted before and after the occurrence of the abnormality among the state data transmitted before and after the occurrence of the abnormality, the estimation accuracy of the state value at the time of occurrence of the abnormality is improved. It can be improved.

(Second Embodiment)
The freeze frame data storage system according to the first embodiment includes ECUs 10A to 10C and 40 mounted on the vehicle V. On the other hand, in the present embodiment shown in FIG. 7, a freeze frame data storage system is composed of ECUs 10 </ b> A to 10 </ b> C and 40 mounted on the vehicle V and an external device 50 </ b> A outside the vehicle.

  Specifically, in the first embodiment, the estimation means 45d of the master ECU 40 exhibits the function of estimating the state value at the abnormality occurrence time ta. On the other hand, in the present embodiment, the external device 50A has estimation means that performs the function. Therefore, in the first embodiment, the estimated value Da of the state value at the time of occurrence of the abnormality is left as FF data in the EEPROM 42. However, in this embodiment, the state data and the change rate data immediately before the time of occurrence of the abnormality are converted to FF data. As shown in FIG. Then, after the repair worker connects the external device 50A to the master ECU 40, the estimation means of the external device 50A estimates the estimated value Da of the state value at the time of occurrence of the abnormality based on the FF data.

  Therefore, according to the present embodiment, the state value at the time of occurrence of the abnormality can be estimated with high accuracy without shortening the predetermined cycle for transmitting the state data to the communication bus 30. Therefore, the reliability of the FF data can be improved. It is possible to realize both reduction of the load on the communication bus 30. Further, according to the present embodiment in which the state value is estimated using such an external device 50A, the transition of the state value close to the actual data shown by the solid line in FIG. 3 is performed based on the abnormal time series data and the latest time series data. Can be obtained.

(Third embodiment)
In the first embodiment, the change amount or inclination of the state values D11 and D10 of the state data and the state values Db11 and Db10 (see FIG. 8) one reference time before the state values D11 and D10 are changed. It is transmitted to the transmission bus 30 as rate data. In contrast, in the present embodiment, the above-described “state values Db11 and Db10 one reference time ago” are transmitted to the transmission bus 30 as change rate data.

  If these state values Db11 and Db10 are transmitted, the amount of change or rate of change of the state values D11 and D10 can be specified. Therefore, the state value Da at the abnormality occurrence time point ta can be estimated in the same manner as in the first embodiment, and the same effect as in the first embodiment is also exhibited by this embodiment.

  In short, in the first embodiment, data representing the gradient of the state value is transmitted as change rate data, whereas in the present embodiment, not the state value gradients DΔ11 and DΔ10 themselves, but the state value Db11 that can identify the gradient. , Db10 can be said to be transmitted as change rate data. Here, the amount of data is smaller for the slope than for the state value. Therefore, the case where the slope is the change rate data as in the first embodiment has a greater effect of reducing the load on the communication bus 30 than the present embodiment.

(Fourth embodiment)
In this embodiment, when the state data and the change rate data are sequentially transmitted from the slave ECUs 10A to 10C to the master ECU 40, the data transmission is temporarily stopped when the load on the communication bus 30 is large. Specifically, when the master ECU 40 constantly detects the load on the communication bus 30 and the detected load is equal to or greater than a predetermined value, the master ECU 40 instructs the slave ECUs 10A to 10C to stop transmission. Then, the time when the transmission is stopped is stored in the EEPROM 42, and the state value at the time when the transmission is stopped is estimated based on the state data and the change rate data transmitted immediately after the transmission is stopped.

(Fifth embodiment)
Here, when the period for transmitting the state data and the change rate data to the communication bus 30 is sufficiently short, the time closest to the time of occurrence of the abnormality is not required even if the state value at the time of occurrence of the abnormality is not estimated based on the change rate data. The state data transmitted to the state may be used as the state value at the time of occurrence of an abnormality. In the present embodiment in view of this point, the change rate data is transmitted to the communication bus 30 on condition that the transmission cycle is longer than a predetermined value. For this reason, since the change rate data is not transmitted until the estimation is unnecessary, the load reduction of the communication bus 30 can be promoted.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and may be modified as follows. Moreover, you may make it combine the characteristic structure of each embodiment arbitrarily, respectively.

  In the first embodiment, with respect to the latest time series data and abnormal time series data, the state values at the timings of regular t10, t20,... T60 are estimated, and the estimated values are used as time series data. However, the state data transmitted at the time closest to the periodic t10, t20... T60 timing may be used as time series data instead of the estimated value.

  In the first embodiment, abnormal time-series data is created using the latest time-series data. However, state data transmitted at a timing closest to the timings of regular t10, t20,. May be used as abnormal time-series data.

  In the first embodiment, the state value used for the time series data is periodically stored at a predetermined time interval, but may be periodically stored at a predetermined data point interval.

  In the third embodiment, “state values Db11 and Db10 one reference time before” are transmitted as change rate data, but the state values two reference times before and three state values before May be transmitted as change rate data. However, the greater the time interval between the state value of the state data and the state value of the change rate data, the worse the estimation accuracy of the state value Da at the time of occurrence of the abnormality ta. Is desirable.

  In the first embodiment, the change rate data is calculated using the “state value before one reference time”, but the state value two reference times before or the state value three minutes before is used. Then, change rate data may be calculated. However, as the change rate data is calculated using the state value immediately before the state data, the estimation accuracy of the state value Da at the abnormality occurrence time ta is improved.

  In each of the above embodiments, the FF data is stored in the EEPROM 42, but may be stored in a flash memory. Further, instead of storing them in these nonvolatile memories, they may be stored in a volatile backup memory. The backup memory is a memory in which the FF data can be stored even when the ignition switch is turned off by turning on the power to the backup memory even when the main power of the master ECU 40 is turned off. .

  10A, 10B, 10C ... slave ECU (slave device), 13c ... transmission means, 30 ... communication bus, 40 ... master ECU (master device), 45b ... storage means during abnormality, 45d, 50d ... estimation means, D1-D20 ... State data, DΔ1 to DΔ20, Db10, Db11 ... change rate data, V ... vehicle.

Claims (6)

A slave device (10A, 10B, 10C) which is mounted on the vehicle (V) and sequentially acquires a state value representing the state of the vehicle;
A master device (40) mounted on a vehicle and capable of communicating with the slave device via a communication bus (30);
With
The slave device transmits state data (D1 to D20) representing the state value and change rate data (DΔ1 to DΔ20, Db10, and Db11) that can specify a change rate of the state value at a predetermined cycle. Transmission means (13c) for transmitting to
The master device is
An estimation means (45d) for estimating the state value at the time of occurrence of an abnormality based on the state data and the change rate data transmitted from the slave device when the occurrence of an abnormality is detected;
Storage means (45b) at the time of abnormality for storing data representing the state value estimated by the estimation means in the storage device (42) as freeze frame data;
I have a,
The estimation means includes
Of the plurality of state data transmitted in a predetermined cycle, compare the transmission time of the state data transmitted immediately before the occurrence of the abnormality and the state data transmitted immediately after the occurrence of the abnormality,
A freeze frame data storage system characterized by estimating the state value at the time of occurrence of an abnormality using the state data transmitted at a time close to the time of occurrence of the abnormality and the change rate data thereof . A slave device (10A, 10B, 10C) which is mounted on the vehicle (V) and sequentially acquires a state value representing the state of the vehicle;
A master device (40) mounted on a vehicle and capable of communicating with the slave device via a communication bus (30);
An external device (50A) which is a device external to the vehicle and capable of communicating with the master device;
With
The slave device transmits state data (D1 to D20) representing the state value and change rate data (DΔ1 to DΔ20, Db10, and Db11) that can specify a change rate of the state value at a predetermined cycle. Transmission means (13c) for transmitting to
The master device has a storage device (45b) at the time of abnormality for storing data including at least the state data and the change rate data at the time of occurrence of abnormality in the storage device (42) as freeze frame data,
The freeze frame data storage system, wherein the external device has an estimation means (50d) for estimating the state value at the time of occurrence of an abnormality based on the freeze frame data. The estimation means includes
Of the plurality of state data transmitted in a predetermined cycle, compare the transmission time of the state data transmitted immediately before the occurrence of the abnormality and the state data transmitted immediately after the occurrence of the abnormality,
3. The freeze frame data storage system according to claim 2 , wherein the state value at the time of occurrence of the abnormality is estimated using state data transmitted at a time close to the time of occurrence of the abnormality and change rate data thereof. . The master device has periodic storage means (45c) for periodically storing the state data and the change rate data transmitted at a predetermined cycle at predetermined intervals,
The regular memory means among data periodically stored, for data from the current time to a predetermined time before any of claims 1 to 3, characterized in that stored when the storage device as a series data (42) freeze frame data storage system according to one or. 5. The storage device according to claim 4 , wherein, when the occurrence of an abnormality is detected, the periodic storage unit stores data in a period including at least an abnormality occurrence time in the time series data as freeze frame data in the storage device. Freeze frame data storage system.   6. The freeze frame data storage system according to claim 1, wherein the change rate data is data (DΔ1 to DΔ20) representing a slope of the state value.

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