JP7110640B2 - vehicle data recorder - Google Patents

Description

The present invention relates to a vehicle data recording device.

In the vehicle failure diagnosis apparatus disclosed in Patent Document 1, when an abnormality such as an engine stall occurs in the vehicle, vehicle parts that may fail are listed. Then, for each listed vehicle part, an active test is performed to forcibly create a situation that is unlikely to occur in the vehicle, thereby sequentially determining the presence or absence of a failure. Then, the fault diagnosis device erases from the list the vehicle parts determined to have no fault. In this way, the list is finally narrowed down to the vehicle parts determined to be at risk of failure.

JP 2009-293951 A

A vehicle engine stall may occur due to a failure of a vehicle component or due to a user's operation of the vehicle. In the failure diagnosis device of Patent Literature 1, when an engine stall occurs without failure of a vehicle component, it cannot be determined whether or not the engine stall is caused by a user's vehicle operation.

A vehicle data recording device for solving the above problems is a vehicle data recording device comprising a data storage unit for storing information relating to the operating state of the vehicle when an engine stall occurs in the vehicle, An engine stall determination unit that determines whether or not an engine stall occurs in the vehicle based on the engine speed of the engine, a shift position detection unit that detects the shift position of the shift lever for operating the automatic transmission, and a shift position change. a recording execution unit for recording, in the data storage unit, the elapsed time from when the operation is performed until it is determined that the engine stall has occurred in the vehicle as information relating to the operation state of the vehicle.

Causes of engine stall include, in addition to failure of vehicle parts, erroneous or inappropriate operation of a shift lever by a user. When an engine stall occurs due to such a user's operation of the shift lever, there is a high possibility that the engine stall will occur immediately after the shift position is changed.

According to the above configuration, by referring to the elapsed time stored in the data storage unit, whether or not the cause of the engine stall is caused by the change of the shift position by the user is determined based on the elapsed time. can be determined as

1 is a schematic diagram of a vehicle; FIG. The figure showing an example of FFD which concerns on occurrence of an engine stall. 4 is a flowchart showing the procedure of time measurement processing; A time chart showing temporal changes in each parameter before and after an engine stall occurs.

An embodiment of a vehicle data recording device will be described below with reference to the drawings. First, a schematic configuration of a vehicle in which the data recording device is mounted will be described.
As shown in FIG. 1, the vehicle is equipped with an engine 80 as a driving source of the vehicle. An automatic transmission 82 is drivingly connected to the crankshaft of the engine 80 . The vehicle is also equipped with a crank angle sensor 12 for detecting the rotational position of the crankshaft of the engine 80 and a vehicle speed sensor 16 for detecting the vehicle speed. An air-fuel ratio sensor 14 is attached to the exhaust pipe of the engine 80 to detect the air-fuel ratio of the exhaust gas flowing through the exhaust pipe.

A shift device 90 for operating the automatic transmission 82 is provided in the passenger compartment of the vehicle. The shift device 90 includes a shift lever 92 for operating an automatic transmission 82 operated by a vehicle driver, and a shift position sensor 18 for detecting the shift position of the shift lever 92 . The shift positions of the shift lever 92 include, for example, a drive position (D position) for advancing the vehicle, a reverse position (R position) for reversing the vehicle, a parking position (P position) for parking the vehicle, A neutral position (N position) for disengaging the gears in the automatic transmission 82, and the like. The shift position sensor 18 is composed of, for example, a plurality of Hall IC sensors provided for each position of the shift lever 92 and outputs a signal corresponding to the shift position of the shift lever 92 . Specifically, when the shift lever 92 is in the drive position, the shift position sensor 18 outputs an ON signal from the Hall IC sensor corresponding to the drive position, and outputs an ON signal from the Hall IC sensor corresponding to the other position. Outputs an off signal.

Next, a vehicle data recording device will be described. The vehicle is equipped with an electronic control unit 30 (hereinafter abbreviated as ECU 30) that comprehensively controls the operating state of the vehicle. In this embodiment, the ECU 30 functions as a vehicle data recording device. The ECU 30 is configured as a computer including a computing unit 32 that executes a program (application), a volatile memory 34 that temporarily stores data when the program is executed, a non-volatile memory 36 that stores the program, and the like. there is The detected values of the sensors installed in the vehicle are input to the ECU 30 .

The non-volatile memory 36 of the ECU 30 functions as a data storage section 42 that stores information relating to the operating state of the vehicle. The data storage unit 42 is divided into a data storage area 42a in which new data can be overwritten and a non-overwriteable area 42b as a storage area for storing information relating to the operating state of the vehicle. Data in the non-overwritable area 42b is cleared by, for example, carrying out a specific work at a maintenance shop or the like.

The calculation section 32 of the ECU 30 functions as a data calculation section 50 . The data calculator 50 calculates the engine speed of the engine 80 based on the detection signal of the crank angle sensor 12 . The data calculator 50 calculates the vehicle speed based on the detection signal from the vehicle speed sensor 16 . The data calculator 50 calculates the excess air ratio in the engine 80 based on the detection signal of the air-fuel ratio sensor 14 . The data calculator 50 records each calculated parameter in the volatile memory 34 .

The calculation section 32 of the ECU 30 functions as a shift position detection section 52 . The shift position detector 52 detects the current shift position of the shift lever 92 based on the detection signal from the shift position sensor 18 . Also, the shift position detection unit 52 sets a position flag according to the detection result of the shift position of the shift lever 92 . Specifically, for example, the shift position detection unit 52 sets the value of the position flag to "1" when the detected position of the shift lever 92 is the drive position, and the detected position of the shift lever 92 is reverse. If it is in position, the value of the position flag is set to "2". Further, the shift position detection unit 52 sets the value of the position flag to "3" when the detected position of the shift lever 92 is the parking position, and sets the value of the position flag to "3" when the detected position of the shift lever 92 is the neutral position. Set the value of the flag to "4". The set position flag value is stored in the volatile memory 34 at any time.

The computing section 32 of the ECU 30 functions as a time measuring section 54 . The time measurement unit 54 determines whether or not the shift position of the shift lever 92 has been changed based on the change in the value of the position flag set by the shift position detection unit 52 . Then, the time measurement unit 54 measures the elapsed time T after the shift position of the shift lever 92 is changed. The time measuring unit 54 repeatedly executes a time measuring process, which is a process for measuring the elapsed time T, at predetermined counter time N (for example, a predetermined time of 0.1 seconds or less). The time measurement unit 54 sequentially stores the elapsed time T updated in the time measurement process in the volatile memory 34 . Note that the time measurement unit 54 sets a comparison flag as a flag for determining whether or not the shift position of the shift lever 92 has been changed in the time measurement process. Specifically, the time measurement unit 54 sets a comparison flag as a flag for comparing the position flag during execution of the time measurement process with the position flag during execution of the next time measurement process.

The calculation unit 32 of the ECU 30 functions as an engine stall determination unit 56 . The engine stall determination unit 56 determines whether or not the vehicle is in an engine stall based on the engine speed of the engine 80 calculated by the data calculation unit 50 . Specifically, the engine stall determination unit 56 determines that the engine has stalled in the vehicle when the engine speed of the engine 80 remains below a predetermined threshold value for a certain period of time. The predetermined threshold value is, for example, the minimum engine speed at which the engine 80 can continue to operate independently, that is, the engine speed in the idling state of the vehicle.

The calculation section 32 of the ECU 30 functions as a recording execution section 58 . The recording execution unit 58 reads the value of the shift position flag detected and set by the shift position detection unit 52 (ECU 30) from the volatile memory 34 at every predetermined sample time (for example, 0.5 seconds). Further, the recording execution unit 58 reads the engine speed, vehicle speed, and excess air ratio of the engine 80 calculated by the data calculation unit 50 from the volatile memory 34 at each sample time. Also, the recording execution unit 58 reads the elapsed time T measured by the time measurement unit 54 from the volatile memory 34 at each sample time. Each of these data read by the recording execution unit 58 constitutes information (hereinafter abbreviated as vehicle information H) relating to the operating state of the vehicle. Then, the recording execution unit 58 records the vehicle information H in the data storage area 42a of the data storage unit 42 for each sample time. In the data storage area 42a of the data storage unit 42, data recorded by the recording execution unit 58 are stored in chronological order. Here, in the data storage area 42a of the data storage unit 42, allocation of data capacity writable by the recording execution unit 58 is determined in advance. In the data storage area 42a of the data storage unit 42, the oldest data is overwritten with new data, and only the amount of data that fits within the data capacity is stored in chronological order. Note that the sample time described above is longer than the counter time described above.

When the engine stall determination unit 56 detects the engine stall of the vehicle, the recording execution unit 58 sets, among the vehicle information H, the vehicle information H at the timing before and after the engine stall detection as data to be saved. Specifically, the recording execution unit 58 treats the vehicle information H recorded in the data storage area 42a of the data storage unit 42 immediately after the engine stall is detected as the vehicle information H at the time of engine stall detection. Then, the vehicle information H at three timings before the vehicle information H when the engine stall is detected and the vehicle information H at the next timing of the vehicle information H when the engine stall is detected are set as data to be stored. That is, the recording execution unit 58 sets the vehicle information H at a total of five timings across the engine stall detection time as data to be saved. Then, when the recording execution unit 58 records the vehicle information H at the timing subsequent to the vehicle information H at the time of engine stall detection in the data storage area 42a of the data storage unit 42, the recording execution unit 58 stores the vehicle information H set as data to be saved as data. It is moved to the overwrite-disabled area 42 b in the storage unit 42 . As a result, in the non-overwritable area 42b of the data storage unit 42, five pieces of vehicle information H that are consecutive in time series are stored. The vehicle information H stored in the non-overwritable area 42b of the data storage unit 42 constitutes so-called freeze frame data (hereinafter abbreviated as FFD) indicating the vehicle state when an abnormality occurs in the vehicle. The FFD is read out at a maintenance shop or the like, and is useful when analyzing the cause of an abnormality in the vehicle.

FIG. 2 shows an example of the vehicle information H stored in the non-overwritable area 42b of the data storage unit 42, that is, the FFD. In the FFD, after the engine speed of the engine 80, the vehicle speed, the on/off information of each shift position of the shift lever 92 (information indicated by the value of the position flag), the excess air ratio, and the shift position of the shift lever 92 are changed are arranged in chronological order across the engine stall detection time. In the example shown in FIG. 2, the shift lever 92 is input to the reverse position before and after the engine stall is detected. Also, the vehicle speed is 0 or higher. In other words, the engine stall is detected while the vehicle is running. FFD includes the elapsed time T from when the shift position of the shift lever 92 is changed until it is determined that the vehicle has stalled. In the example shown in FIG. 2, the elapsed time T when it is determined that the vehicle has stalled is 2.70 seconds. Although FIG. 2 shows ON/OFF information for the drive position and the reverse position, the FFD similarly stores ON/OFF information for other shift positions.

As described above, the FFD includes the elapsed time T from when the shift position of the shift lever 92 is changed until it is determined that the vehicle has stalled. That is, the recording execution unit 58 sets the elapsed time T from when the shift position of the shift lever 92 is changed to when it is determined that the vehicle has stalled, as the vehicle information H, to the overwrite-disabled area 42b of the data storage unit 42. to record.

Next, a processing procedure of time measurement processing executed by the time measurement unit 54 of the ECU 30 will be described. The time measurement unit 54 starts time measurement processing when the ignition switch is turned on. The time measurement unit 54 repeatedly executes the time measurement process every counter time N. Note that the elapsed time T is set to 0 when the ignition switch is turned on.

As shown in FIG. 3, when the time measuring unit 54 starts the time measuring process, the process proceeds to step S110. In step S110, the time measuring unit 54 updates the elapsed time T according to the following formula (1).

New elapsed time T=elapsed time before update T+counter time N (1)
The "elapsed time T before update" in equation (1) is 0 when the current time measurement process is the first time measurement process after the ignition switch is turned on; is the elapsed time T updated in the previous time measurement process.

After completing the process of step S110, the time measuring unit 54 advances the process to step S120. In step S120, the time measurement unit 54 determines whether or not the current time measurement process is the second or subsequent time measurement process after the ignition switch is turned on. When the current time measurement process is the first time measurement process after the ignition switch is turned on (step S120: NO), the time measurement unit 54 advances the process to step S125. Then, the time measurement unit 54 reads the value of the position flag set by the shift position detection unit 52 in step S125. Then, the time measurement unit 54 sets the value of the position flag to the value of the comparison flag. The value of this comparison flag is compared with the value of the position flag read by the time measurement unit 54 in the next time measurement process in the next time measurement process. After completing the process of step S125, the time measurement unit 54 advances the process to step S160.

If the time measuring unit 54 determines in step S120 that the current time measuring process is the second or subsequent time measuring process after the ignition switch is turned on (step S120: YES), the process proceeds to step S130. proceed to

When the time measuring section 54 proceeds to step S130, the time measuring section 54 determines whether or not the shift position of the shift lever 92 has been changed. Specifically, the time measurement unit 54 first reads the value of the position flag set by the shift position detection unit 52 . Then, the time measurement unit 54 compares the value of the read position flag and the value of the comparison flag. When the value of the position flag and the value of the comparison flag are different, the time measurement unit 54 determines that the shift position of the shift lever 92 has been changed. On the other hand, when the value of the position flag and the value of the comparison flag match, the time measurement unit 54 determines that the shift position of the shift lever 92 has not been changed.

If the shift position of the shift lever 92 has been changed (step S130: NO), the time measurement unit 54 advances the process to step S140. In this case, the time measuring unit 54 resets the elapsed time T to zero. Then, the time measurement unit 54 advances the process to step S150. On the other hand, if the shift position of the shift lever 92 has not been changed (step S130: YES), the time measurement unit 54 directly proceeds to step S150.

In step S150, the time measurement unit 54 sets the value of the position flag read in step S130 as the value of the comparison flag. After that, the time measurement unit 54 advances the process to step S160. In step S<b>160 , the time measurement unit 54 records the elapsed time T in the volatile memory 34 . After that, the time measuring unit 54 ends the time measuring process.

Next, the flow of processing performed by the time measurement unit 54, the engine stall determination unit 56, and the recording execution unit 58 of the ECU 30 will be described together with the running state of the vehicle. Here, consider the running state of the vehicle as shown in FIG. The vehicle is traveling forward at a substantially constant speed from time t1. At this time, the shift position of the shift lever 92 is the drive position. Further, the engine speed of the engine 80 is substantially constant. At time t2, while the vehicle is moving forward, the shift position of the shift lever 92 is switched from the drive position to the reverse position. As a result, the running direction of the vehicle and the direction of the gears of the automatic transmission 82 do not match, and the engine speed of the engine 80 gradually decreases. Then, the state in which the engine speed of the engine 80 is lower than the predetermined threshold value continues for a certain period of time until time t3. After that, the engine speed of the engine 80 becomes 0, and the vehicle stops running.

When the vehicle is in the running state shown in FIG. 4, the time measuring unit 54 of the ECU 30 updates the elapsed time T after the shift position of the shift lever 92 is changed from time t1 to time t2. The time measurement unit 54 resets the elapsed time T to 0 at time t2 when the shift position of the shift lever 92 is switched from the drive position to the reverse position. Then, the time measurement unit 54 updates the elapsed time T again from time t2.

When the vehicle is in the running state shown in FIG. 4, the engine stall determination unit 56 of the ECU 30 determines that the vehicle has stalled at time t3. After that, the recording execution unit 58 of the ECU 30 sets the vehicle information H when the engine stall is detected and the vehicle information H at the three timings before the vehicle information H when the engine stall is detected as data to be saved, as described above. . In addition, the recording execution unit 58 sets the vehicle information H at the timing subsequent to the vehicle information H at the time of detection of the engine stall as data to be saved. Then, the recording execution unit 58 moves the vehicle information H set as data to be saved from the data storage area 42a to the non-overwritable area 42b. In this manner, the vehicle information H at timings before and after the engine stall is detected is stored in the non-overwritable area 42b of the data storage unit 42. FIG.

Next, the effects of this embodiment will be described.
In the present embodiment, vehicle information H at timings before and after engine stalling is detected is stored in a non-rewritable area 42b of the data storage unit 42 configured by the non-volatile memory 36 . The data stored in the nonvolatile memory 36 remains in the nonvolatile memory 36 without being erased even when the ignition switch is turned off. Therefore, the vehicle information H stored in the non-overwritable area 42b of the data storage unit 42 can be read by a worker when inspecting the vehicle at a maintenance shop or the like.

By the way, as a cause of an engine stall in a vehicle, in addition to the failure of vehicle parts, there is an erroneous or inappropriate operation of a shift lever by a user. As described above, when the direction of travel of the vehicle and the direction of the gears of the automatic transmission 82 do not match due to the operation of the shift lever 92, the vehicle stalls. When the engine stalls in the vehicle due to the operation of the shift lever 92, there is a high possibility that the engine stalls immediately after (several seconds) after the shift position of the shift lever 92 is changed.

Here, in the present embodiment, vehicle information H at timings before and after engine stalling is detected is stored in the non-overwritable area 42b of the data storage unit 42 . This vehicle information H includes vehicle speed, information on ON/OFF of each shift position of the shift lever 92, and elapsed time T after the shift position of the shift lever 92 is changed. Therefore, at a maintenance shop or the like, a worker can refer to this information to estimate the cause of the engine stall. Specifically, by referring to the above information, the operator can determine whether or not the vehicle was running with the shift position of the shift lever 92 set to the drive position or reverse position when the engine stall was detected. can determine whether In addition, the operator can determine whether or not the engine stall was detected in the vehicle immediately after the shift position of the shift lever 92 was changed. If the vehicle is in a running state when the engine stall is detected, and if the timing at which the vehicle engine stall is detected is immediately after the shift position of the shift lever 92 is changed, the worker determines the cause of the engine stall. is due to the change of the shift position of the shift lever 92 by the user. Furthermore, in the present embodiment, the vehicle information H stored in the non-overwritable area 42b of the data storage unit 42 includes the excess air ratio of the engine 80. FIG. If there is no abnormality in the excess air ratio before and after detection of the engine stall, it can be estimated with a high probability that the engine stall is caused by the user changing the shift position of the shift lever 92 .

As described above, according to the present embodiment, by referring to the vehicle information H stored in the non-overwritable area 42b of the data storage unit 42, the operator can determine that the cause of the engine stall of the vehicle is the shift lever 92 by the user. It becomes possible to diagnose whether it is caused by the change of the shift position. Therefore, it is possible to distinguish whether the engine stall of the vehicle is caused by the user's operation or by the failure of the vehicle parts, making it easier to identify the cause of the engine stall.

By the way, it is assumed that the elapsed time T is not included in the vehicle information H stored in the non-overwritable area 42b of the data storage unit 42. FIG. In such a case, if an attempt is made to diagnose the relationship between the engine stall of the vehicle and the change in the shift position of the shift lever 92 by the user, the vehicle speed and the shift lever 92 are detected from a timing considerably earlier than the vehicle engine stall is detected. Information on the on/off of the shift position and information on the excess air ratio in the engine 80 are required. In other words, regarding these data, it is necessary to store long-term data in the overwrite-disabled area 42b of the data storage unit 42 from a timing considerably earlier than the detection of the engine stalling of the vehicle. In this case, the data capacity to be stored in the non-overwritable area 42b of the data storage unit 42 becomes large, and the storage capacity of the nonvolatile memory 36 is largely occupied. In this regard, according to the present embodiment, the elapsed time T after the shift position of the shift lever 92 is changed at the timing when the engine stall is detected is stored in the overwrite-disabled area 42b of the data storage unit 42. Therefore, it is possible to diagnose the relationship between the engine stall of the vehicle and the change of the shift position of the shift lever 92 by the user without using data over a long period of time. Therefore, the storage capacity of the nonvolatile memory 36 is not excessively occupied.

In addition, this embodiment can be changed and implemented as follows. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
- The type of data of the vehicle information H stored in the non-overwritable area 42b of the data storage unit 42 is not limited to that shown in the above embodiment. The vehicle information H stored in the non-overwritable area 42b of the data storage unit 42 may include the elapsed time T after the shift position of the shift lever 92 was changed. For example, the vehicle information H stored in the non-overwritable area 42b of the data storage unit 42 may include, in addition to or instead of each data of the above-described embodiment, the amount of intake air in the engine 80, the temperature of the cooling water in the engine 80, and the like. may be included. It should be noted that, depending on the type of data to be included in the vehicle information H, various sensors required to acquire the requested data may be installed in the vehicle.

With respect to the vehicle information H to be stored in the non-overwritable area 42b of the data storage unit 42, the position of the data in the time direction may be shifted back and forth in the time direction across the detection of the engine stall. For example, vehicle information H at two timings before and after the vehicle information H at the time of engine stall detection may be stored in the overwrite-disabled area 42b of the data storage unit 42 .

- Regarding the vehicle information H stored in the non-overwritable area 42b of the data storage unit 42, the number of pieces of data relating to the time direction may be changed from that shown in the above embodiment. For example, the vehicle information H from the timing four or more before the vehicle information H when the engine stall is detected to the timing two or more after the vehicle information H when the engine stall is detected is stored in the data storage unit 42 overwrite-disabled area. 42b may be stored.

As for the vehicle information H to be stored in the overwrite-disabled area 42b of the data storage unit 42, it is not essential to store the vehicle information H at timings before and after the engine stall detection in the data storage unit 42. As for the vehicle information H, at least the vehicle information H at the time of detection of the engine stall should be stored in the non-overwritable area 42 b of the data storage unit 42 .

The recording execution unit 58 records the vehicle information H in the volatile memory 34 in chronological order for each sample time. to the non-overwritable area 42 b of the data storage unit 42 .

- The processing procedure and processing method in the time measurement processing executed by the time measurement unit 54 can be changed as appropriate. In the time measurement process, it is sufficient if the elapsed time T after the shift position of the shift lever 92 is changed can be calculated.

- The counter time N, which is the cycle of repeating the time measurement process, can be changed as appropriate. Here, the time scale of the elapsed time T at which the engine stall of the vehicle can be considered due to the operation of the shift lever 92 by the user is several seconds. Therefore, in diagnosing the relationship between the engine stall of the vehicle and the change in the shift position of the shift lever 92 by the user, it is necessary to update the elapsed time T on a time scale shorter than the time scale of several seconds. The counter time N should be set so that the elapsed time T can be updated on such a time scale.

The sample time during which the recording execution unit 58 reads various data to be the vehicle information H and records them in the data storage unit 42 can be changed as appropriate. As described above, the time scale of the elapsed time T at which the engine stall of the vehicle can be considered due to the operation of the shift lever 92 by the user is several seconds. Therefore, in diagnosing the relationship between the engine stall of the vehicle and the change in the shift position of the shift lever 92 by the user, it is necessary to update (record) the vehicle information H on a time scale shorter than the time scale of several seconds. . The sample time should be set so that the vehicle information H can be updated on such a time scale.

- Regarding the relationship between the sample time and the counter time, the sample time may be the same as the counter time, or may be shorter than the counter time. For example, regarding the vehicle information H other than the elapsed time T, it is effective to set the sample time shorter than the counter time when it is desired to record the data at time intervals that are finer than when the elapsed time T is updated.

A threshold value of the elapsed time T at which the engine stall of the vehicle can be considered to occur due to the operation of the shift lever 92 by the user is set in advance. may be executed by the ECU 30 to notify the user by lighting the .

- The data recording device of a vehicle is not limited to what is comprised by ECU30. For example, a measuring device capable of collecting various data related to the vehicle information H may be installed in the vehicle, and the measuring device may function as a data recording device.

42 Data storage unit 52 Shift position detection unit 56 Engine stall determination unit 58 Record execution unit 80 Engine 82 Automatic transmission 92 Shift lever H Vehicle information T Elapsed time.

Claims (1)

A data recording device for a vehicle, comprising a data storage unit for storing information relating to an operating state of the vehicle when an engine stall occurs in the vehicle,
an engine stall determination unit that determines whether or not an engine stall occurs in the vehicle based on the engine speed of the engine;
a shift position detector that detects a shift position of a shift lever for operating an automatic transmission;
a recording execution unit that records, in the data storage unit, the elapsed time from when the shift position is changed until it is determined that the vehicle has engine stall, as information related to the operating state of the vehicle. Vehicle data recorder.

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