Vehicle control device

Abstract

An in-vehicle control device (100) is achieved, with which it is possible to reduce the risk of important data being lost without being written due to, e.g., a momentary power dip or interruption when multiple data write requests occur simultaneously. The in-vehicle control device (100) comprises: a main memory (150) that stores data; a plurality of auxiliary memories (160, 160-2, 160-3, ..., 160-N) that store data; and a CPU (140), which is a data control unit that performs a data writing process, a data distributing process, and a data saving process with respect to the main memory (150) and the plurality of auxiliary memories (160, 160-2, 160-3, ..., 160-N). If the main memory (150) is in use, the CPU (140) executes the data writing process and the data saving process with respect to any of the plurality of auxiliary memories (160, 160-2, 160-3, ..., 160-N) as an alternative.

Description

[Technical field]

[0001] The present invention relates to a memory storage method for an on-board control device. [Background technology]

[0002] In the on-board control device, important data that needs to be retained, such as information on faults that occur while the vehicle is running and learning information, is stored in a non-volatile memory.

[0003] In recent years, the amount of data to be stored has increased due to the increasing sophistication of on-board control devices and the mandatory installation of data recorder functions that automatically record the operation of the vehicle's accelerator, brakes, etc. in order to clarify the causes of traffic accidents. As a result, there is an increasing number of cases in which highly important data needs to be written to non-volatile memory immediately while driving.

[0004] The on-board control device described in Patent Document 1 employs a method of periodically writing predetermined data to one non-volatile memory while the vehicle is running, thereby retaining necessary data even after the ignition is turned off. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-159247 A Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, in the technology described in Patent Document 1, when the amount of data stored while the vehicle is traveling increases and write requests overlap, arbitration is performed to sequentially write to a single non-volatile memory. However, there is an issue that while waiting for arbitration, there is an increased risk that important data cannot be written due to a momentary dip or interruption in the power supply to the on-board control device.

[0007] An object of the present invention is to provide an in-vehicle control device that can reduce the risk of important data being lost due to failure to write the data due to a momentary power dip or interruption when multiple data write requests occur simultaneously. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention is configured as follows.

[0009] In the on-board control device, data Centralize A main memory for storing the The memory is divided into a high-immediacy memory, a medium-immediacy memory, and a low-immediacy memory, The system includes a plurality of auxiliary memories that store data, and a data control unit that performs a data write process, a data allocation process, and a data storage process for the main memory and the plurality of auxiliary memories, and the data control unit: When the data write requests are generated simultaneously, the write target memory is determined according to the importance of the data requested to be written and the distinction of the auxiliary memory, and the data control unit determines whether the write target memory is a write target memory or a read target memory. If in use, alternatively , not in use For any one of the plurality of auxiliary memories The data writing process and the data saving process execution and when the data is distributed and stored in the plurality of auxiliary memories as a result of the data writing process and the data storing process, the data control unit performs a data unification process of unifying and writing the data in the main memory at the time of a shutdown process and a startup process of the in-vehicle control device. Execute. Effect of the Invention

[0010] According to the present invention, it is possible to realize an in-vehicle control device that can reduce the risk of important data being lost due to failure to write the data due to a momentary power dip or interruption, etc., when multiple data write requests occur simultaneously. [Brief description of the drawings]

[0011] [Figure 1] 1 is a configuration diagram showing an example of a vehicle control device according to the present invention; [Diagram 2] 11 is a flowchart illustrating an example of a process for saving data to a main memory and an auxiliary memory. [Diagram 3] 13 is a diagram showing the contents of determining a write target based on the importance of data and memory write immediacy in data allocation processing. FIG. [Figure 4] 13 is a flowchart showing an example of data unification processing during shutdown processing and startup processing. [Diagram 5] FIG. 13 is a diagram illustrating an example of a memory arrangement when data unification processing is performed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, examples of embodiments of the present invention will be described with reference to the accompanying drawings. EXAMPLES

[0013] [Overall configuration] First, a schematic configuration of an on-board control device 100 according to an embodiment of the present invention will be described with reference to FIG.

[0014] In FIG. 1, an on-vehicle control device 100 is a device that electronically controls on-vehicle devices (such as an automatic transmission and an engine) mounted on a vehicle.

[0015] The vehicle-mounted control device 100 includes a power supply circuit 110 connected to a battery 200, a CPU 140 (data control unit), an input / output circuit 120 connected to a sensor / actuator 210, a CAN circuit 130 that communicates with other vehicle-mounted control devices 220 (other control devices) mounted on the same vehicle, a main memory 150 that stores data in response to instructions from the CPU 140, and an auxiliary memory 160.

[0016] When a failure occurs in the sensor / actuator 210 , the CPU 140 can store failure information in the main memory 150 or the auxiliary memory 160 .

[0017] Furthermore, the on-board control device 100 may have a configuration including a plurality of auxiliary memories 160, 160-2, 160-3, . . . 160-N, as shown in FIG.

[0018] [Data storage process in main memory and auxiliary memory] The process of saving data in main memory 150 and auxiliary memory 160 will be described with reference to the flowchart of FIG.

[0019] The data write process, data allocation process, and data save process in this embodiment of the present invention are processes that are performed by CPU 140 when a request to write data to main memory 150 and auxiliary memory 160 occurs.

[0020] In step S001, CPU 140 checks whether main memory 150 is being written to or read from. If main memory 150 is not being written to and is not being read from, the process proceeds to step S002.

[0021] In step S002, CPU 140 requests main memory 150 to write data.

[0022] In step S001, if main memory 150 is being written to or read from, the process proceeds to step S003.

[0023] In step S003, CPU 140 checks whether there is any auxiliary memory 160 that is not being written to and is not being read from. If all auxiliary memories 160 are being written to or read from, the process proceeds to step S004. If there is any auxiliary memory 160 that is not being written to and is not being read from in step S003, the process proceeds to step S005.

[0024] In step S004, the CPU 140 sets a write request in a queue that manages data write requests. Alternatively, the CPU 140 of the in-vehicle control device 100 may use a communication means such as the CAN circuit 130 to transmit data to another in-vehicle control device 220 (another control device) and store the data in a memory held by the other in-vehicle control device 220 as an auxiliary memory. There are multiple memories held by the other in-vehicle control device 220 and the memories may be classified into a high-immediacy memory, a medium-immediacy memory, and a low-immediacy memory, or may be one (or two) of a high-immediacy memory, a medium-immediacy memory, and a low-immediacy memory.

[0025] In step S005, the CPU 140 performs a data allocation process to determine a memory to which data is to be written based on the importance of the write request data and the usage status of each memory. The details of the data allocation process will be described later in [Data Allocation Process] with reference to FIG.

[0026] In step S006, the CPU 140 issues a data write request to the auxiliary memory 160 determined in step S005 of the data allocation process.

[0027] [Data sorting processing] The data allocation process will be explained using Fig. 3. In Fig. 3, unused states are indicated by white circles, and memories selected for writing are indicated by black circles. Data A has low importance, and data B has high importance. Data C and data D have medium importance.

[0028] In addition, auxiliary memory 1, auxiliary memory 2, auxiliary memory 3, ... auxiliary memory N (160, 160-2, 160-3, ... 160-N) are classified into high immediacy memory, medium immediacy memory, and low immediacy memory. In the example shown in Fig. 3, auxiliary memory 1 (160) is a high immediacy memory, auxiliary memory 2 (160-2) is a low immediacy memory, and auxiliary memory 3 (160-3) is a medium immediacy memory.

[0029] The CPU 140 determines the memory to be written to based on the importance of the data and the usage status of each memory in the order of the write requests. As shown in Fig. 3, when a write request for data A occurs in a state where no write request has occurred, the CPU 140 first selects the main memory 150 as the write target.

[0030] Next, when a write request for data B occurs, because main memory 150 is being written to, auxiliary memories 160, 160-2, 160-3, ... 160-N are selected, and the higher the importance of the data requested to be written, the higher the memory with the highest write immediacy is selected for data write processing. Because data B is highly important, auxiliary memory 1 (160) with the highest write immediacy is selected.

[0031] Similarly, for data C and data D, the memory to which the data is to be written is determined taking into consideration the importance of the write request data and the write immediacy of each memory.

[0032] In this way, by selecting a memory with high write immediacy the higher the importance of the write requested data, it is possible to further reduce the risk of important data being lost due to failure to be written.

[0033] [Centralized data processing] 4 is a flowchart showing an example of data unification processing during shutdown processing and startup processing of the in-vehicle control device 100. The data unification processing is processing performed by the CPU 140.

[0034] In the data centralization process, when multiple data write requests overlap during normal control, data saved in the auxiliary memories (160, 160-2, ... 160-N) is centralized and stored in the main memory 150, and thereafter, data management is simplified by reading only the main memory 150.

[0035] In step S101 of FIG. 4, the CPU 140 checks whether data stored during normal control exists in the auxiliary memories (160, 160-2, . . . 160-N).

[0036] If data is stored in the auxiliary memory (160, 160-2, . . . 160-N), the process proceeds to step S102. If data is not stored in the auxiliary memory (160, 160-2, . . . 160-N), the process ends.

[0037] In step S102, CPU 140 updates the data in main memory 150 based on the data stored in auxiliary memories (160, 160-2, . . . 160-N).

[0038] In step S103, the CPU 140 erases the data stored in the auxiliary memories (160, 160-2, . . . 160-N).

[0039] In this way, the data stored in the auxiliary memories (160, 160-2, ... 160-N) is centralized as the data in the main memory 150, and thereafter, the CPU 140 reads the data necessary for control only from the main memory 150, thereby making it easier to manage data.

[0040] The data unification process as described above can be executed, for example, during the shutdown process of the in-vehicle control device 100. That is, by performing the data unification process during the shutdown process, data saved in the auxiliary memories (160, 160-2, . . . 160-N) due to overlapping requests to write a plurality of data during normal control is stored unified in the main memory 150, and only the main memory 150 is read during the next startup process, thereby facilitating data management.

[0041] The data unification process can be executed during the startup process of the in-vehicle control device 100. For example, if the shutdown process of the in-vehicle control device 100 is not performed normally due to an instantaneous drop or interruption of the battery 200 that supplies the power, the data unification process during the shutdown process described above is not executed, and therefore a state in which data is distributed and stored in the main memory 150 and the auxiliary memory (160, 160-2, . . . 160-N) may occur. In such a case, by updating the main memory 150 based on the data in the auxiliary memory (160, 160-2, . . . 160-N) during the startup process of the in-vehicle control device 100, it becomes possible to read data required for control only from the main memory 150 thereafter. In other words, this makes it possible to facilitate data management.

[0042] [Memory allocation by centralized data processing] FIG. 5 shows an example of memory allocation when data centralization processing is performed.

[0043] In FIG. 5, CPU 140 updates the data in the data B area of ​​main memory 150 based on data B stored in auxiliary memory (160, 160-2, ... 160-N) through data unification processing at the time of startup processing or shutdown processing.

[0044] After that, the CPU 140 erases the data B from the auxiliary memories (160, 160-2, . . . , 160-N) and performs control based on the data in the main memory 150.

[0045] The on-board control device 100 according to an embodiment of the present invention has a plurality of memory resources (main memory 150, auxiliary memories 160, 160-2, . . . 160-N) as targets for writing data related to vehicle running and the like.

[0046] In the present invention, CPU 140, which is a data control unit, executes data write processing and data save processing in one of a plurality of auxiliary memories (160, 160-2, . . . 160-N) as an alternative when main memory 150 is in use.

[0047] Therefore, as described above, by having multiple memory resources (main memory 150, auxiliary memory 160, 160-2, ... 160-N), when multiple data write requests occur simultaneously, there is no need to wait, and the risk of important data being lost or unable to be written due to a power dip or interruption while waiting can be reduced to an extremely low level.

[0048] This makes it possible to retain important learned values ​​that would have been lost due to momentary dips or interruptions in the power supply in conventional technology, thereby improving the drivability and safety of the vehicle.

[0049] Furthermore, the data control unit, CPU 140, is configured to determine the memory to which data is to be written based on the importance of the data requested to be written and the usage status of each memory (main memory 150, auxiliary memory (160, 160-2, ... 160-N)) and to perform writing. Therefore, important fault information and the driver's operating status at the time of an accident can be read from the in-vehicle control device 100 by an external or internal in-vehicle diagnostic device, which improves the accuracy of understanding the vehicle's abnormality information and operating status, and contributes to identifying the cause of the accident.

[0050] In addition, by selecting a memory with high write immediacy the higher the importance of the write requested data, it is possible to further reduce the risk of important data being lost due to failure to be written.

[0051] In addition, during the shutdown process and startup process of the vehicle-mounted control device 1, the CPU 140 writes and centralizes the data stored in the auxiliary memories (160, 160-2, ... 160-N) into the data in the main memory 150, so that during the startup process of the vehicle-mounted control device 1, all data necessary for control can be read from the main memory 150 without being left behind.

[0052] In addition, when the main memory 150 is in use, the auxiliary memory (160, 160-2, ... 160-N) that performs data writing processing and data storage processing as an alternative does not have to be the memory of the in-vehicle control device 100 itself, but may be the memory owned by another in-vehicle control device 220 to which writing data can be notified via communication means, etc.

[0053] In addition, in the present invention, the on-vehicle control device also includes a drive recorder that records the status of the host vehicle and the external conditions of the host vehicle, which change from moment to moment.

[0054] According to the present invention, even in a drive recorder serving as an on-board control device, there is no need to wait for data writing even when multiple data write requests are made simultaneously from multiple cameras, and the risk of important data being lost or unable to be written due to a momentary power dip or interruption while waiting can be reduced to the utmost. [Explanation of symbols]

[0055] 100...vehicle-mounted control device, 110...power supply circuit, 120...input / output circuit, 130...CAN circuit, 140...CPU (data control unit), 150...main memory, 160, 160-2, 160-3, 160-N...auxiliary memory, 200...battery, 210...sensor / actuator, 220...other vehicle-mounted control device

Claims

1. A main memory for centrally storing data; A plurality of auxiliary memories for storing the data, the auxiliary memories being classified into a high-immediacy memory, a medium-immediacy memory, and a low-immediacy memory; a data control unit that performs a data write process, a data allocation process, and a data storage process for the main memory and the plurality of auxiliary memories; Equipped with the data control unit is configured to determine a write target memory in response to a level of importance of the data requested to be written and a distinction between the auxiliary memories when write requests for the data are generated simultaneously; when the write target memory is being used for writing or reading, the data control unit executes the data write process and the data save process on one of the plurality of auxiliary memories that is not being used as an alternative; The data control unit is characterized in that, when the data is distributed and stored in the multiple auxiliary memories as a result of the data writing process and the data storage process, the data control unit executes a data centralization process in which the data is centrally written to the main memory during shutdown processing and startup processing of the vehicle control device.

2. The on-board control device according to claim 1 , The data control unit, when the memory to be written to is in use, performs data writing processing and data storage processing in memory owned by another vehicle control device connected via a communication function, and when the vehicle control device is shut down or started up, receives the data stored in the other vehicle control device via the communication function and writes it in a centralized manner to the main memory.

Images