JP5598342B2 - Vehicle data recording device - Google Patents

Description

  The present invention relates to a vehicular data recording apparatus that records data related to the operating state of an in-vehicle control system when a predetermined event occurs.

  For example, Patent Document 1 discloses a data storage device that stores data representing the operating state of a system triggered by the occurrence of a system event. This data storage device includes an analysis target data temporary storage unit that stores analysis target data for a predetermined time or number of acquisitions immediately before, an event occurrence determination unit that determines the occurrence of an event from event occurrence determination data, and the occurrence of an event is determined And a data storage unit that stores data stored in the analysis target data temporary storage unit in association with the event data after a predetermined time.

  As described above, in the apparatus of the cited document 1, by storing the analysis target data in association with the event data, even if the event factor is complex, the analysis target data is associated with the event type, the factor, the condition, and the like. Analysis is possible. Furthermore, since event data itself is stored in association with analysis target data for event factor determination, the amount of data to be stored is reduced, and data can be stored efficiently with a small amount of memory.

Japanese Patent Application Laid-Open No. 2009-3685

  As described above, in the data storage device of Patent Document 1, the analysis target data in a predetermined period before and after the event occurrence is stored in the memory as it is, with the event occurrence as a trigger. The analysis target data includes detection values detected by various sensors, control data output from various control devices, and the like.

  Here, in particular, detection values detected by various sensors have various temporal change characteristics (hereinafter referred to as time constants) depending on the physical quantity to be detected. For example, in an in-vehicle control system mounted on an electric vehicle or a hybrid vehicle using a motor as a drive source, heat data such as battery temperature, behavior data related to vehicle behavior such as vehicle speed and acceleration, motor drive current, etc. Assume that the electric quantity data is data to be analyzed. In this case, generally, the time for which the calorific value data changes is the longest, and the behavior data and the electric quantity data become shorter in this order. As described above, since the time constant of the detection value of each sensor differs according to the physical quantity to be detected, the accuracy of the detection value required at the time of analysis also differs.

  However, the data storage device of Patent Document 1 does not take into account the required accuracy for each detection value of each sensor, and simply stores the detection value detected by each sensor as it is. For this reason, the data storage device of Patent Literature 1 stores even extra information regarding the detection value of the sensor, which causes a problem of wastefully using the memory capacity. Such a problem may also occur with respect to control data output from the control device.

  The present invention has been made in view of the above points, and by recording each data with the accuracy required at the time of analysis in consideration of data change characteristics, the recording capacity required for the recording is further reduced. It is an object of the present invention to provide a vehicular data recording apparatus capable of doing so.

In order to achieve the above object, a vehicular data recording apparatus according to claim 1,
When a predetermined event occurs, data related to the operating state of the in-vehicle control system is recorded in the recording means,
The data related to the operation state of the in-vehicle control system includes two or more types of data that are expressed by digital values and have different time constants that are temporal change characteristics at the time of change ,
For each data type, there is provided a recording control means for setting the number of bits at the time of recording in accordance with the magnitude of the time constant obtained from the actual change amount of the data and recording the data of the set number of bits in the recording means. It is characterized by that.

  Since the data recording device according to claim 1 has the above-described configuration, the data related to the operation state of the in-vehicle control system is recorded with the number of bits corresponding to the time constant when each data changes. Can be recorded on the means. For this reason, each data can be recorded with the accuracy required at the time of analysis. As a result, when recording each data, it is possible to prevent unnecessary information from being recorded and, conversely, necessary information from leaking, and to reduce the recording capacity required for data recording.

  According to a second aspect of the present invention, it is preferable that the recording control means sets the set bit number for data having a large time constant at the time of change smaller than the set bit number for data having a small time constant at the time of change. This is because data with a large time constant at the time of change does not change frequently as compared with data with a small time constant at the time of change, and the required accuracy is relatively low.

  According to a third aspect of the present invention, when the number of bits of data is larger than the set number of bits, the recording control means discards the lower bits and makes the number of bits of the data match the set number of bits. If the lower bits are discarded, it will not be possible to grasp minute changes in the data, but it is less necessary to grasp the minute data changes when analyzing data with a relatively large time constant. This is because the information by the lower bits is often unnecessary.

The vehicle data recording device according to claim 4 is provided .
When a predetermined event occurs, data related to the operating state of the in-vehicle control system is recorded in the recording means,
The data related to the operating state of the in-vehicle control system includes two or more types of data expressed by digital values and having different time constants at the time of change,
According to the time constant, setting the number of bits at the time of recording for each type of data, comprising a recording control means for recording the data of the set bit number in the recording means,
The recording control means divides the data into a plurality of groups based on the approximation of the time constant, and provides a plurality of A / D converters provided for each group, each having a different number of bits after the data is converted into a digital value. And recording data converted into digital values by a plurality of A / D converters in a recording means, and A / D by an A / D converter provided for a group having a small time constant the number of bits after conversion, than the number of bits of the a / D converted by the time the a / D converter provided for a large group constant and said multi Ikoto.
Thereby, the number of bits of data after A / D conversion by the A / D converter can be brought close to the number of bits corresponding to the accuracy obtained from the time constant. Therefore, in the A / D converter, it is possible to avoid as much as possible the wasteful A / D conversion process. Further, when the number of bits after A / D conversion by the A / D converter matches the number of bits according to the accuracy obtained from the time constant, the data after A / D conversion is recorded as it is. Will be able to.

  According to a fifth aspect of the present invention, when the recording control means records the data converted into digital values by the plurality of A / D converters on the recording means, the time information at the time of the conversion is also recorded. It is preferable to record in the recording means. In this way, it is possible to grasp the temporal relationship between the data converted into digital values while converting the data into digital values using a plurality of A / D converters.

  According to the sixth aspect of the present invention, the data recording apparatus performs the same by interpolating the data recorded in the recording means and converted into digital values by the plurality of A / D converters based on the time information. You may make it provide the same time data calculation means which calculates the data in time. Thereby, for example, the vehicle diagnostic device can easily analyze the operation state of the in-vehicle control system at the time of event occurrence from the data acquired from the data recording device.

  As described in claim 7, the in-vehicle control system is configured by a plurality of electronic control devices, and the data is detected by a sensor that detects a physical quantity related to the operation state of the in-vehicle control system, and is converted into a digital value. The detection signals detected by the sensors are collected for each group, taken into different electronic control units, and digitalized by an A / D converter provided for the fetched electronic control unit. It can be configured to be converted to a value. That is, for each group, an A / D converter and an electronic control unit for handling data included in the group may be individually provided.

  According to the eighth aspect of the invention, the recording unit performs recording in units of data having a predetermined number of bits, and the recording control unit stores two or more pieces of data so as to be equal to or less than the predetermined number of bits. It is preferable to record in combination on the recording means. Thereby, the capacity for recording data in the recording means can be compressed, and the recording capacity can be further reduced.

It is the block diagram which showed the structure for controlling driving | running | working of the hybrid vehicle with which the vehicle data recording device by embodiment is applied as a block diagram. It is a figure for demonstrating an example of functional arrangement | positioning in each ECU in the case of comprising the control system of a hybrid vehicle by several ECU. It is a flowchart which shows the process which determines generation | occurrence | production of an abnormal event in the recording process for recording data when an abnormal event generate | occur | produces, and manages the log | history. 5 is a flowchart showing a process for setting an optimum data length for each recording target data and performing data recording with the optimum data length in a recording process for recording data when an abnormal event occurs. It is a flowchart which shows the detail of the data recording process in the flowchart of FIG. In a modification, it is a flowchart which shows the process which one ECU in a vehicle data recording device performs, when a vehicle diagnostic device reads the data recorded on the data recording device for vehicles.

  Hereinafter, a vehicle data recording apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, an example in which the vehicle data recording device is applied to a hybrid vehicle having an engine and a motor as a travel drive source of the vehicle will be described, but the application target is a vehicle having only an engine, An electric vehicle having only a motor may be used.

  FIG. 1 is a block diagram showing, in particular, a block diagram of a configuration for controlling traveling of a hybrid vehicle. As shown in FIG. 1, the hybrid vehicle includes an engine 11 and a motor generator (MG) 32 as a travel drive source. The MG 32 is disposed on the output shaft of the engine 11. Further, a continuously variable transmission (CVT) 21 is connected to the output shaft of the engine 11.

  The MG 32 operates by receiving power supply from a battery (battery) 51 mounted on the vehicle, and can assist the driving force of the engine 11. Further, when the vehicle decelerates, the MG 32 generates power by rotational driving from the wheel side and charges the battery 51 (energy regeneration). In such a configuration, if a clutch is provided between the engine 11 and the MG 32 so that the engine 11 and the MG 32 can be disconnected, the vehicle can be driven only by the driving force of the MG 32. It becomes.

  The CVT 21 includes a forward / reverse switching mechanism, and generally includes a metal belt that connects an input shaft connected to an output shaft of the engine 11 and an output shaft connected to a drive shaft via a main clutch for starting. This is a continuously variable transmission having a simple structure. In other words, the CVT 21 can change the gear ratio steplessly by changing the pulley width of the pulleys provided on the input shaft and the output shaft, for example, using hydraulic pressure, and changing the winding radius of the metal belt. Is something. However, instead of the CVT 21, an automatic transmission having a plurality of preset gear ratios can be used.

  In addition, although an example in which a so-called parallel system configuration is provided as a hybrid system has been described, hybrid systems using other systems (split system, series / parallel system, etc.) can also be used.

  The brake device 71 can generate a braking force by using, for example, hydraulic pressure or an electric motor regardless of the operation of the brake pedal by the driver. The electric power steering device (EPS) 81 assists the steering force when the driver steers the steering wheel with an electric motor.

  The human machine interface (HMI) 61 means an operation unit operated by a driver for driving a hybrid vehicle, and includes, for example, an accelerator pedal, a brake pedal, a steering wheel, a shift lever, and the like. Each operation amount in the operation unit is detected by a sensor or the like and input to the hybrid ECU 60. However, the detection signal from the sensor may be input to another ECU, or the sensor itself may be communicably connected to the ECU via a communication line.

  The environment vehicle interface (EVI) 62 acquires information about the external environment where the hybrid vehicle is placed. For example, the environment vehicle interface (EVI) 62 acquires a radar device that detects a preceding vehicle or an obstacle, and an image around the vehicle. Applicable to cameras. When this information is obtained, for example, the speed of the host vehicle is adjusted so as to follow the preceding vehicle (adaptive cruise control), or the white line is recognized from the image and the traveling lane defined by the white line is not deviated. As described above, the assist force by the electric power steering device (EPS) 81 can be adjusted (lane keep control).

  In the present embodiment, as shown in FIG. 1, the hybrid vehicle control system includes an engine ECU 10, a CVTECU 20, an MGECU 30, an energy management ECU 40, a battery ECU 50, a hybrid (HV) ECU 60, a brake ECU 70, and an EPS ECU 80. These ECUs are connected to each other via a communication line so that they can communicate with each other.

  An example of functional arrangement in each ECU when a control system of a hybrid vehicle is configured by the plurality of ECUs will be described with reference to FIG.

  The energy management ECU 40 manages the energy consumption of the entire vehicle and bears the function of running the vehicle most efficiently. Specifically, the energy management unit 41 manages the capacity of the battery 51 based on input information from various sensors, and calculates MG torque that can be generated by the MG 32 based on the capacity of the battery 51. To do.

  Regarding the capacity management of the battery 51, when the capacity of the battery 51 fluctuates due to a change in temperature or when the battery temperature rises excessively, the battery 51 may be damaged. For this reason, the energy management unit 41 outputs the battery target temperature to the temperature adjustment unit 42. The temperature adjustment unit 42 includes a cooling unit 43 for driving a cooling device that cools the battery 51 or a heating unit 44 for driving a heating device that raises the temperature of the battery 51 based on the target battery temperature. Use to adjust the temperature of the battery 51.

  In addition, the energy management unit 41 detects a charge level that is a ratio of the remaining charge to the charge capacity of the battery 51, and instructs the charge / discharge adjustment unit 45 to charge / discharge to prevent overcharge or overdischarge of the battery 51. Is output. The charging / discharging adjustment unit 45 outputs a control signal to the plug-in charging unit 52 and the SOC management unit 54 in the battery ECU 50 according to the charging / discharging command, and adjusts the charging level of the battery 51 to an appropriate range. In addition, since the charge capacity of the battery 51 changes according to the deterioration state (SOH) of the battery 51, the SOC management unit 54 uses the information from the SOH management unit 53 to control the charge level of the battery 51.

  For example, the HVECU 60 has a function of inputting information from various sensors such as an accelerator sensor, a brake sensor, a shift position sensor, and a steering sensor and controlling the behavior of the vehicle so as to correspond to the operation of the driver in principle. . Specifically, the vehicle behavior control unit 63 outputs the target acceleration (deceleration) in the front-rear direction to the front-rear behavior adjustment unit 64, and the target acceleration in the left-right direction to the left-right behavior adjustment unit 81 of the EPS ECU 80. By outputting, the behavior of the vehicle is controlled so as to respond to the operation of the driver while stabilizing the behavior of the vehicle.

  The front / rear behavior adjusting unit 64 outputs a target driving torque and a target braking torque to the driving force control unit 65 and the braking force control unit 72 in order to realize the given target acceleration in the front / rear direction. The driving force control unit 65 considers the maximum MG torque that can be generated by the MG 32 acquired from the energy management unit 41 in order to achieve the target driving torque most efficiently, while the engine control unit 12 controls the target engine torque and MG control. The target MG torque is given to the unit 33, and the target gear ratio is given to the CVT control unit 22, respectively.

  The engine control unit 12 controls the operating state of the engine 11 by adjusting the throttle valve opening, the fuel supply amount, and the like so that the engine 11 generates the target engine torque based on information such as the engine speed. The MG control unit 33 outputs a drive signal for controlling the operation state of the MG 32 based on information such as the rotation speed and rotation position of the MG 32 so that the MG 32 generates the target MG torque. Output to. The CVT control unit 22 controls the gear ratio of the CVT 21 to the target gear ratio so that the driving torque generated by the engine 11 and the MG 32 is appropriately transmitted to the driving wheels.

  In addition, the braking force control unit 72 gives a target brake braking torque to the brake control unit 73, a target regenerative braking torque to the MG control unit 33, and a target speed ratio to the CVT control unit 22 in order to realize the target braking torque.

  The brake control unit 73 drives the brake fluid pressure and the electric motor so that the brake device 71 generates the target brake braking torque based on information such as the wheel speed of each of the four wheels and the fluid pressure of each of the four wheels. Control. The target brake braking torque is calculated so as to compensate for the shortage when the target regenerative braking torque is insufficient with respect to the target braking torque. In this case, the MG control unit 33 controls the MG 32 to operate as a generator (generator), and the electricity generated by the MG 32 is charged in the battery 51.

  Further, the left / right behavior adjusting unit 82 outputs a target assist torque to the EPS control unit 83 in order to realize the given target acceleration in the left / right direction. The EPS control unit 83 controls the EPS 81 so that the assist torque generated by the EPS 81 becomes the target assist torque based on information such as the drive current of the electric motor.

  Note that the above-described function arrangement in each ECU is merely an example, and the allocation of functions to each ECU can be changed. Further, for example, a plurality of ECUs can be appropriately integrated, for example, the engine 11 and the CVT 21 are controlled by a common ECU.

  As described above, in a hybrid vehicle including the engine 11 and the MG 32 as a travel drive source, for example, the hybrid ECU 60 calculates target torques of the engine 11 and the MG 32 according to the driver's acceleration request (accelerator pedal depression amount). The engine 11 and the MG 32 are output to the ECUs 10 and 30. Then, the ECUs 10 and 30 control the engine 11 and the motor MG 32 according to the calculated target torque. As described above, in a hybrid vehicle, torque for driving the vehicle is controlled by a plurality of ECUs. Therefore, there is a possibility that abnormal behavior of the vehicle may be caused by interference operations of the plurality of ECUs. Increased compared to other vehicles.

  Therefore, some abnormal event (for example, abnormal operation such as sudden change in accelerator depression amount or sudden change in brake depression amount, abnormal behavior such as sudden acceleration, sudden deceleration (rapid stop) and sudden turning of the vehicle, etc.) In the past, it was possible to record the data related to the operating state of each on-board control system at that time, and to later elucidate the cause of the occurrence of an abnormality. It is made from. Such data includes detection signals detected by various sensors, control data output from various in-vehicle devices and ECUs, and the like.

  However, if the above data is recorded as it is, the memory capacity required to record the data will increase. In particular, in hybrid vehicles, the amount of information to be recorded as data tends to increase, and such a problem appears remarkably.

  Therefore, in the present embodiment, it is possible to record necessary data with as little memory capacity as possible. Hereinafter, a configuration for recording data and a recording method in the present embodiment will be described in detail.

  First, in this embodiment, a specific ECU (specifically, hybrid ECU 60), as a rule, inputs a signal from a sensor that outputs a signal to be recorded, and the sensor signal is incorporated into a built-in A / D converter. A case will be described in which A / D conversion is performed and data necessary for analysis such as control signals output from other ECUs is collected and recorded together. That is, in this embodiment, the hybrid ECU 60 mainly constitutes a vehicle data recording device.

  However, it is not excluded that an ECU other than the hybrid ECU 60 exceptionally inputs a signal from a sensor that is data necessary for analysis. In this case, the hybrid ECU 60 may receive the sensor signal from another ECU. It is also possible to connect the sensor itself to a communication line and output a signal directly from the sensor to the hybrid ECU 60.

  The memory in which the hybrid ECU 60 records data necessary for analysis is non-volatile, and even if the ignition switch of the vehicle is turned off and the power supply to the hybrid ECU 60 is stopped, the hybrid ECU 60 stores the recorded data. Can be held. The hybrid ECU 60 temporarily records data necessary for analysis in the volatile memory, and writes the data recorded in the volatile memory to the nonvolatile memory at an appropriate timing, for example, when the ignition is off. Anyway.

  The memory of the hybrid ECU 60 is capable of recording data for a first predetermined time, and the hybrid ECU 60 always writes data in its own memory in an infinite loop. This writing is performed at regular time intervals (for example, 1 second).

  At the same time, the hybrid ECU 60 determines whether an abnormal event has occurred based on event occurrence determination data such as an input sensor signal. When it is determined that an abnormal event has occurred, the hybrid ECU 60 stops data recording when a second predetermined time has elapsed from the determination time. As a result, in the memory of the hybrid ECU 60, data for the first predetermined time-second predetermined time before the occurrence of the abnormal event and data for the second predetermined time after the occurrence of the abnormal event are recorded. .

  The data recorded in the memory of the hybrid ECU 60 includes a sensor signal that detects an operation by the driver. This is because the operation by the driver affects the operating state of each in-vehicle control system. Examples of such sensors include an accelerator pedal sensor that detects the amount of depression of the accelerator pedal, a brake pedal sensor that detects the amount of depression of the brake pedal, a shift position sensor that detects the shift position of the transmission, and the steering angle of the steering wheel. For example, a steering sensor for detecting The data recorded in the memory also includes a sensor signal that detects the behavior of the vehicle that changes under the control of each in-vehicle control system. Examples of such a sensor include a speed sensor that detects the traveling speed of the vehicle, an acceleration sensor that detects acceleration in the front-rear direction and the left-right direction of the vehicle, and a yaw rate sensor that detects a change speed in the rotation direction of the vehicle. .

  In addition, as data recorded in the memory, the temperature of the engine 11, the MG32, and the battery 51, the current value and the rotation speed of the MG32, the charge level (SOC) and the deterioration state (SOH) of the battery 51, the liquid of the brake device Pressure etc. are included. Further, the data recorded in the memory may include control signals for various control systems of the hybrid vehicle. For example, a control signal for an electric power steering control system, a control signal for a brake control system, a control signal for a CVT control system, and a control signal for an engine control system. This is because the assist force of the EPS 81, the braking force of the brake device 71, the transmission ratio of the CVT 21, the torque of the engine 11 and the like are changed by control signals from these control systems.

  Hereinafter, a recording process for recording data when an abnormal event occurs performed in the vehicle data recording apparatus of the present embodiment will be described with reference to the flowcharts of FIGS. In addition, the flowchart of FIGS. 3-5 has shown as an example the recording process in case the sudden change of the accelerator depression amount has arisen as an abnormal event. The processing shown in the flowcharts of FIGS. 3 to 5 is started when the ignition of the vehicle is turned on, and thereafter repeatedly executed at regular intervals.

  In the flowchart of FIG. 2, first, in step S100, the amount of change per unit time of the accelerator depression amount is detected. In the subsequent step S110, it is determined whether or not the amount of change in the accelerator depression amount detected in step S100 is equal to or greater than a predetermined value. If “Yes” is determined in step S110, the process proceeds to step S120, and if “No” is determined, the process proceeds to step S130.

  In step S120, it is considered that an abnormal event in which the accelerator operation amount changes suddenly occurs, and an accelerator sudden change event history is set. On the other hand, in step S130, it is determined whether or not the processing of step S120 has been executed in the past and the accelerator sudden change event history has been set. If “Yes” is determined in step S130, the process proceeds to step S140. When a new accelerator sudden change event occurs, the accelerator sudden change event history is recorded so that the data recording process can be performed at that timing. Cancel.

  Next, the process shown in the flowchart of FIG. 4 will be described. In the flowchart of FIG. 4, first, in step S200, it is determined whether or not an accelerator sudden change event history is set. If it is determined “Yes” in step S200, the process of step S210 is executed. If it is determined “No”, the process of step S250 is executed. In step S250, the determination result of the time constant in step S220 described later is cleared, and the determination of the time constant is performed when a new event history is set.

  In step S210, data temporarily recorded in the volatile memory is read and a temporal change amount is detected. In the detection of the temporal change amount, for example, a time required for a predetermined change (such as a time required to increase or decrease to a predetermined ratio), a change rate per unit time, and the like are detected. In subsequent step S220, the magnitude of the time constant is determined based on the temporal change detected in step S210. In step S230, an optimum data length for recording data is set according to the size of the time constant determined in step S220.

  Here, the time constant is a temporal change characteristic of data and changes variously according to the physical quantity that the data means. For example, in a hybrid vehicle, heat quantity data such as the temperature of the engine 11 and the battery 51, chemical quantity data such as the degree of deterioration (SOH) and charge level (SOC) of the battery 51, hydraulic pressure data such as brake hydraulic pressure, It is assumed that behavior data relating to vehicle behavior such as speed and acceleration, and electrical quantity data such as motor drive current are stored in a memory as data necessary for analysis. In this case, in general, the amount of time for which the calorific data changes is the longest, and the chemical quantity data, the hydraulic pressure quantity data, the behavior data, and the electric quantity data become shorter in this order. Thus, since the time constant of each data differs according to the physical quantity that each data means, the accuracy of data required at the time of analysis also differs.

  Thus, since the data precision required at the time of analysis differs, the optimal data length as each data also differs. In this respect, in the present embodiment, as described above, the time constant size of each data is determined, and the optimum data length is set based on the size of the time constant. Each data can be recorded. As a result, when recording each data, it is possible to prevent unnecessary information from being recorded and, conversely, necessary information from leaking, and to reduce the memory capacity required for data recording. Since each data is represented by a digital value, the data length corresponds to the number of bits of each data.

  The setting of the optimum data length will be described. The data length for data having a large time constant (that is, it takes a relatively long time to change) is preferably shorter than the data length for data having a small time constant. This is because data with a large time constant does not change frequently as compared with data with a small time constant, so that the required accuracy is relatively low.

  In the above-described example, the time constant is determined based on the actual change amount of the recording target data, and the optimum data length is set. In this way, a data length suitable for the actual change characteristics of each data when an abnormal event occurs can be set for each data.

  However, since the change characteristics of each data usually fall within a certain range for each data, the optimum data length may be predetermined for each data.

  In the subsequent step S240, processing for recording each data in the memory is executed according to the data length set as described above. This recording process will be described with reference to the flowchart of FIG. In the flowchart of FIG. 5, an example is shown in which the length of the data length determined by the time constant is divided into three types, but the number of divisions is not limited to three types.

  In the flowchart of FIG. 5, first, in step S300, the length of the optimum data length set in step S230 is determined for the data to be recorded. Specifically, the optimum data length is compared with predetermined values 1, 2, and 3. The relationship between the predetermined values 1, 2, and 3 is predetermined value 1 <predetermined value 2 <predetermined value 3. Accordingly, in the determination process of step S300, it is determined whether the optimum data length is greater than the predetermined value 1 and less than or equal to the predetermined value 2, or greater than the predetermined value 2 and less than or equal to the predetermined value 3 or greater than the predetermined value 3. The

  If it is determined that the optimum data length is greater than the predetermined value 1 and less than or equal to the predetermined value 2, the process proceeds to step S310, and the data package 1 in which data having similar data lengths are collected is recorded.

  Similarly, if it is determined that the optimum data length is greater than the predetermined value 2 and less than or equal to the predetermined value 3, the process proceeds to step S320, and the data package 2 in which data having similar data lengths are collected is recorded. If it is determined that the optimum data length is greater than the predetermined value 3, the process proceeds to step S330, and the data package 3 in which data having similar data lengths are collected is recorded and recorded.

  When creating each data package, if the actual data length is longer than the set optimum data length, the lower bits of the data are discarded and the data length (number of bits) is optimized. Match the data length (optimum number of bits). If the lower bits are discarded, it will not be possible to grasp minute changes in the data, but it is less necessary to grasp the minute data changes when analyzing data with a relatively large time constant. This is because the information by the lower bits is often unnecessary.

  When data is stored in a memory, recording is performed in units of a predetermined number of bits (8, 16, 32 bits, etc.). For this reason, when each data package is created, if the combined length of two or more pieces of data is less than or equal to a predetermined number of bits, the two or more pieces of data are combined. Thereby, the memory capacity for recording the data package can be compressed.

  In the above-described example, an example in which data packages having similar data lengths are collected to create a data package has been described. However, a data package in which all data to be recorded is collected may be created. In this case, since it is possible to combine data having various data lengths, it is possible to further reduce the memory capacity.

  In step S340, it is determined whether the recording process for all data to be recorded has been completed. If the processing has not been completed for all data, the processing from step S300 is repeated.

  By performing the recording process as described above, each data can be recorded with the accuracy required at the time of analysis. In other words, when each data is recorded, it is possible to prevent unnecessary information from being recorded and conversely necessary information from leaking.

  Then, the data recorded in this way can be read out and analyzed by the vehicle diagnostic apparatus, which can be used for elucidating the cause of the abnormality.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. .

  For example, in the above-described embodiment, in principle, a specific ECU inputs a signal from a sensor that outputs a signal to be recorded, and A / D converts the sensor signal by a built-in A / D converter. Furthermore, data necessary for analysis such as control signals output from other ECUs are collected and recorded together.

  However, for example, among the data to be recorded, sensor signals that detect physical quantities related to the operating state of the in-vehicle control system are divided into a plurality of groups based on the approximation of the time constant of each sensor signal. You may make it input into different ECU for every. In this case, the sensor signal input to each ECU is converted into a digital value by an A / D converter provided in each ECU and recorded in a memory in each ECU.

  At this time, the number of bits after A / D conversion by the A / D converter provided for the group having a small time constant is equal to the A / D by the A / D converter provided for the group having a large time constant. Each A / D converter may be selected so as to be larger than the number of bits after conversion. By adopting such a configuration, the number of bits of data after A / D conversion by the A / D converter can be brought close to the number of bits according to the accuracy obtained from the time constant. Therefore, in the A / D converter, it is possible to avoid as much as possible the wasteful A / D conversion process. Further, when the number of bits after A / D conversion by the A / D converter matches the number of bits according to the accuracy obtained from the time constant, the data after A / D conversion is recorded as it is. Will be able to.

  However, as described above, when A / D conversion is performed by the A / D converter of each ECU, the time timing at which the sensor signal is A / D converted may be shifted for each group. Therefore, it is preferable to record the time information at the time when the A / D conversion is performed in the memory. In this way, it is possible to grasp the temporal relationship between the sensor signals of different groups while converting the data into digital values using separate A / D converters provided in each ECU. .

  Specifically, when the vehicle diagnostic apparatus reads out the data recorded in the vehicle data recording apparatus, one ECU in the vehicle data recording apparatus may execute the processing shown in the flowchart of FIG. .

  In the flowchart of FIG. 6, first, in step S400, the sensor signal and time information recorded in the memory of each ECU are read for each type of sensor signal. In subsequent step S410, the sensor signal is interpolated based on the time information. In step S420, a sensor signal at the same time is calculated from the interpolated sensor signal, and in step S430, each sensor signal that is data at the same time is output. The sensor signals at the same time are calculated at regular intervals and output to the vehicle diagnostic apparatus.

  Thereby, the vehicle diagnostic apparatus can easily analyze the operation state of the in-vehicle control system when the abnormal event occurs from the data read from the vehicle data recording apparatus. In addition, by interpolating the sensor signals in this way, it is possible to output a sensor signal in accordance with the shortest sampling period even when the sampling periods of the sensor signals are different.

10 Engine ECU
11 engine 20 continuously variable transmission ECU
21 continuously variable transmission 30 motor generator ECU
32 Motor generator 40 Energy management ECU
50 Battery ECU
51 battery 60 hybrid ECU
70 Brake ECU
71 Brake device 80 Electric power steering ECU
81 Electric power steering device

Claims (8)

A data recording device that records data related to the operation state of the in-vehicle control system in a recording means when a predetermined event occurs,
The data related to the operating state of the in-vehicle control system includes two or more types of data expressed by digital values and having different time constants that are temporal change characteristics at the time of change ,
For each type of data, the number of bits at the time of recording is set according to the magnitude of the time constant obtained from the actual change amount of the data, and the data having the set number of bits is recorded in the recording means. A data recording apparatus comprising a recording control means.   2. The data recording according to claim 1, wherein the recording control means sets a set bit number for data having a large time constant at the time of change smaller than a set bit number for data having a small time constant at the time of change. apparatus.   3. The recording control unit according to claim 2, wherein when the number of bits of the data is larger than the set number of bits, the lower order bits are discarded and the number of bits of the data is made to match the set number of bits. Data recording device. A data recording device that records data related to the operation state of the in-vehicle control system in a recording means when a predetermined event occurs,
The data related to the operating state of the in-vehicle control system includes two or more types of data that are expressed by digital values and have different time constants at the time of change,
According to the time constant, setting the number of bits at the time of recording for each type of data, comprising recording control means for recording the data of the set number of bits in the recording means,
The recording control means includes
The data is divided into a plurality of groups based on the approximation of the time constant, provided for each group, and comprising a plurality of A / D converters having different numbers of bits after the data is converted into digital values,
The data converted into digital values by the plurality of A / D converters is recorded in the recording means,
The number of bits after A / D conversion of the A / D converter provided for the group having a small time constant is the A / D conversion of the A / D converter provided for the group having a large time constant. A data recording apparatus characterized in that the number of bits is larger than the later number of bits.   When the recording control means records data converted into digital values by the plurality of A / D converters in the recording means, time information at the time of the conversion is also recorded in the recording means. The data recording apparatus according to claim 4, wherein:   Simultaneous data calculation means for calculating data at the same time by interpolating the data recorded in the recording means and respectively converted into digital values by the plurality of A / D converters based on the time information The data recording apparatus according to claim 5, further comprising: The in-vehicle control system is composed of a plurality of electronic control devices,
The data includes data that is detected by a sensor that detects a physical quantity related to the operating state of the in-vehicle control system and converted into a digital value,
The detection signals detected by the sensors are grouped for each group, taken into different electronic control devices, and converted into digital values by A / D converters provided for the taken-in electronic control devices. The data recording apparatus according to claim 4, wherein the data recording apparatus is a data recording apparatus. The recording means performs recording in units of data having a predetermined number of bits,
The recording control means compresses a capacity for data recording in the recording means by combining two or more data and recording them in the recording means so as to be equal to or less than the predetermined number of bits. The data recording device according to any one of claims 1 to 3.

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