The present application relates to an in-vehicle network system.
In recent years, in order to verify environmental information around a vehicle, vehicle recognition, and determination and statuses of operational actions when an accident occurs during automatic driving that needs no driver’s operation of the vehicle, it requires input/output data of the control ECU (electric control unit), the sensors, and the actuators. In-vehicle network systems have been known that communicate via relay ECUs between an integrated controller and a plurality of sensors, actuators and the likes provided in a vehicle, and an in-vehicle network system has been further proposed that additionally provided with a data recorder function. For example, Patent Document 1 discloses a low-cost data-collection in-vehicle network configured by narrowing down the number of storage devices, in which control ECUs are connected to lines dedicated to each function of a vehicle and a storage device is provided to a gateway ECU for relaying data communication on each line, thus enabling collection and transmission of signals from/to sensors and actuators through the in-vehicle network with high efficiency and high probability when an event occurs.
Patent Document 1: JP5561186B (Paragraph [0041],
An in-vehicle network system for realizing automatic driving deals with a large amount of data output from a plurality of sensors, thus posing a problem of needing to select a storage device having a fast write speed. Moreover, losing the function of the gateway ECU having the storage device raises a problem of losing a significant amount of information collected and transmitted.
The present application is made to resolve problems such as described above and aimed at providing an in-vehicle network system that effectively collects statues of automatic driving operations and increases survivability of the collected information.
An in-vehicle network system disclosed in the present application includes sensors configured to acquire information about a vehicle; actuators configured to control travel of and interior environment of the vehicle; a control command unit configured to output control signals for controlling the actuators on the basis of data of the vehicle information acquired by the sensors; a plurality of storage devices configured to store the data of the vehicle information acquired by the sensors and data of the control signals output from the control command unit; and a storage controller configured to allocate and stores the data of the vehicle information and the data of the control signals to and in the plurality of storage devices, wherein the storage controller generates parities corresponding to the allocated data and stores data of the parities in at least one of the storage devices.
According to the present invention, by allocating and storing vehicle information data and vehicle control signal data to and in a plurality of storage devices, even if any of these data is lost, the lost data can be restored, thus being able to increase survivability of the stored data.
The integrated controller unit 2 receives information data from sensors 5, 6 via the relay ECUs 3, 4 to grasp environment around the vehicle 1 and the levels of driver’s operations, and gives operational commands to actuators 7, 8, 9. The integrated controller unit 2 is provided with, for example, a system on chip (SoC) and a volatile memory (DRAM) to manipulate the information data from each sensor to give the commands to the actuators. Moreover, the integrated controller unit 2 has a storage devices 13a for holding the information data received from each of the sensors 5, 6, the command data for the actuators 7, 8, 9, and software for the integrated controller unit 2 to execute. A non-volatile memory such as, for example, a flash memory is used for the storage devices 13a. Note that while one integrated controller unit 2 is provided in Embodiment 1, a plurality of integrated controller units may be connected to the backbone network for a case of requiring a sophisticated processing and redundancy in, for example, automatic driving with driver’s hands off or the like.
The relay ECUs 3, 4 are connected to the integrated controller unit 2 through the backbone network to send the information data acquired from the sensors 5, 6 to the integrated controller unit 2 and to send operational commands received from the integrated controller unit 2 to the actuators 7, 8 connected with the relay ECUs 3, 4 and to the actuator 9 via the control ECU 10 connected with the relay ECU 3. The relay ECUs 3, 4 have a routing function of sorting the operational commands sent from the integrated controller unit 2 to the actuators 7, 8 and the control ECU 10, respectively. Moreover, the relay ECUs 3, 4 have storage devices 13b, 13c, respectively, for holding information data received from each of the sensors 5, 6 and the command data for the actuators 7, 8, 9. A non-volatile memory such as, for example, a flash memory is used for the storage devices 13b, 13c. Note that while the two relay ECUs are provided in Embodiment 1, integrated controller units, actuators, and control ECUs in the vehicle are, for example, segmented on the area basis and relay ECUs may be provided for each area.
The relay ECUs 3, 4 and the integrated controller unit 2, actuators 7, 8, and the control ECU 10 are connected by communication lines that are formed in any one of a star connection, a loop connection, and a bus connection, or combination thereof. For example, in a case of the vehicle 1 having an automatic driving function, a malfunction due to a disconnection in the backbone communication is prevented by making dual redundant the loop connection or the star connection of the backbone communication line connecting between the relay ECUs 3, 4 and the integrated controller unit 2.
The sensors 5, 6 have functions such as of, for example, a radar, a camera, a thermosensor, a steering angle sensor, an accelerator pedal sensor, and a brake pedal sensor to grasp the surrounding environment of and the interior environment of the vehicle 1 and operations by the driver. Information data sensed by the sensors 5, 6 are sent to the relay ECUs 3, 4. Note that while the sensors 5, 6 are respectively connected only to the relay ECUs 3, 4 in Embodiment 1, the sensors may be connected not only to the relay ECUs 3, 4 but also to the control ECU 10 and the integrated controller unit 2.
The actuators 7, 8 have functions of driving and controlling operations of, for example, the steering motor, the engine equipment, the wiper motors, power window motors, and the like relating to travelling, curving, and stopping of the vehicle 1, and of driving and controlling the air-conditioner equipment and the like for making the interior environment comfortable. Note that the actuators 7, 8 may be connected to the control ECU 10 or the integrated controller unit 2 as with the actuator 9.
The control ECU 10 is connected to the relay ECU 3 to drive the actuator 9 on the basis of a control command signal from the integrated controller unit 2. The control ECU 10 is provided with a microcomputer for transforming the control command signal from the integrated controller unit 2 into a waveform for driving the actuator 9. Note that while only one control ECU 10 is provided in Embodiment 1, a plurality of control ECUs may be provided. Moreover, the control ECU 10 may be connected not only to the relay ECU 3 but also to the integrated controller unit 2.
As shown in
The integrated controller unit 2 is provided with a storage controller 15 for identifying items of and setting a writing period of data to be accumulated in the storage devices 13a, 13b, 13c and/or the storage devices 14 and for deleting and overwriting data accumulated therein. In the case of the network system having both of the storage devices 13a, 13b, 13c and the storage devices 14 as in Embodiment 1, the integrated controller unit 2 may be provided in any one of or both of the vehicle 1 and the management unit 12. Although it is more efficient to provide such storage controllers 15 in the relay ECUs 3, 4 and the integrated controller 2 to each of which data are gathered, the storage controller(s) 15 may be provided in, for example, any one of or both of the integrated controller 2 and the relay ECUs 3, 4. While one integrated controller unit and one ECU usually perform communication for control between the vehicle 1 and the management unit 12, priority for the storage controllers may be determined, for example, depending on the amount of collected data in a case of a plurality of storage controllers 15 being provided in the integrated controller unit 2 and the relay ECUs 3, 4.
The storage controller 15 monitors the traffic on the backbone communication line and changes each cycle for storing data in the storage devices 13a, 13b, 13c and/or the storage devices 14 to ensure real-time performance in controlling the vehicle 1. Moreover, data to be stored is prioritized beforehand. When communication speed of the backbone communication line is decreased at a moment of occurrence of an event, only prioritized data is stored in the storage devices 13a, 13b, 13c and/or the storage devices 14 to keep the traffic normal.
The integrated controller unit 2, the relay ECUs 3, 4, and the management unit 12 have respective difference extraction functions 16a, 16b, 16c, 16d for extracting differences in data received from each of the sensors 5, 6 and in command data for each of the actuators 7, 8, 9 and the control ECU 10. In addition, such a difference extraction function may be implemented only in hardware incorporating the storage controller 15.
The integrated controller unit 2 includes a processor 200 and a memory 201 as shown by an example of the hardware of
Next, data storage techniques in the in-vehicle network system according to Embodiment 1 are described specifically.
The storage controller 15 allocates data to be written to the storage devices 13a, 13b, 13c and/or the storage devices 14, and generates an error correction code (parity) to store them in any of the storage devices 13a, 13b, 13c and the storage devices 14. It is a known technique that when part of data lost, the data can be restored by combining their parities and the remaining data.
In the in-vehicle network system 100 according to Embodiment 1, the data storage technique is set to any of those of Example 1 to Example 4. When the set storage technique is changed, the storage controller 15 cancels storage areas in the storage devices 13a, 13b, 13c and the storage devices 14 or changes them to different storage areas to assign anew areas for writing the data and the parities.
In setting a data storage technique among those of Examples 1 to 4, the storage areas for the information data from the sensors 5, 6 and the control signal data for the actuators 7, 8 and the control ECU 10 can be arbitrarily set. When the setting is changed through OTA (over the air), the storage controller 15 cancels the storage areas or change them to different storage areas to assign anew areas for writing the data and the parities.
In order to serve the in-vehicle network system as a data recorder, in a case of adding time information when an event occurs, the storage controller 15 allocates the time information as one data similarly to the information data from the sensors 5, 6 and the control signal data for the actuators 7, 8 and the relay ECU 10. The time information may be added by the sensor controller 15 or time information used for time synchronization of the backbone network may be utilized. Note that a known technique is used to detect an event. For example, thresholds may be set for the information from the sensors to detect an event.
Next, a procedure for the in-vehicle network system 100 according to Embodiment 1 to operate as the data recorder is described with reference to
Firstly, a check is made whether the vehicle 1 is in an active state (an ignition-on state) (S001). When the vehicle 1 is active (“Yes” in S001), a check is made by the storage controller 15 whether areas for writing data are assigned to the storage devices 13a, 13b, 13c, and/or the storage devices 14 (S002). When the vehicle 1 is not active (“No” in S001), a wait is made until the vehicle 1 is activated.
If areas for writing data have been already assigned (“Yes” in S002), the areas for writing data are set (S004). If areas for writing data have been not yet assigned (“No” in S002), a data storage technique is arbitrarily selected among those of Example 1 to Example 4. After setting of the storage technique, the data to be written are allocated to areas in the storage devices 13a, 13b, 13c and/or the storage devices 14 by the storage controller 15 (S003).
In determining areas for writing data (S004), data is preferentially recorded in an unused area among reserved areas in the storage devices 13a, 13b, 13c and the storage devices 14; otherwise, data with no time information, in other words, data when no event occurs is deleted once to use the area in which the deleted data is recorded. If the storage devices 13a, 13b, 13c and the storage devices 14 do not satisfy the above criterion, stored data with the oldest time information is deleted once to use the area in which the deleted data is recorded.
After areas for writing data are determined, information data from the sensors 5, 6 are collected via the relay ECUs 2, 3 (S005). The collected data are written in the assigned storage areas by the storage controller 15 (S006). The information data from the sensors 5, 6 are input to the integrated controller unit 2 through the backbone communication line, and control signals are output to the actuators 7, 8 and the control ECU 10 by the integrated controller unit 2. The control signals are output through the backbone communication line via the relay ECUs 3, 4 (S007). The control signal data are written in the assigned storage areas through the backbone communication line (S008).
Furthermore, parities are generated by the storage controller 15 on the basis of the written information data from the sensors 5, 6 and the written control signal data for the actuators 7, 8 and the control ECU 10 (S009). The generated parities are stored in the assigned storage areas by the storage controller 15 (S010).
When an event occurs (“Yes” in S011), time data is generated (S012). The time data is stored in the area assigned beforehand by the storage controller 15 (S013). After finishing storing the time data, if the vehicle 1 is travelling (“No” in S014), then the procedure returns to S004.
When no event occurs (“No” in S011), information data from the sensors 5, 6 are collected via the relay ECUs 2, 3 (S015). The differences between the collected data and the last collected ones are extracted using the difference extraction functions 16 and are written in the storage areas beforehand assigned by the storage controller 15 (S016).
The collected information data in S015 are input to the integrated controller unit 2 and control signals are output to the actuators 7, 8 and the control ECU 10 by the integrated controller unit 2 (S017). In writing of the output control signal data, only differences from the last control signal data for the actuators 7, 8 and the control ECU 10 are extracted by the difference extraction functions 16, and the differences are written in the beforehand assigned storage areas by the storage controller 15 (S018). After the difference data are written, the procedure returns to S009.
When the vehicle 1 is stopping or parking (“Yes” in S014), the locations to which the data are allocated and the areas in which the data are written are held by the storage controller 15 (S019), and then the procedure ends.
As described above, the in-vehicle network system according to Embodiment 1 includes the sensors 5, 6 for acquiring information about the vehicle 1; the actuators 7, 8, 9 for controlling travel of and interior environment of the vehicle 1; the integrated controller unit 2 for outputting control signals for controlling the actuators 7, 8, 9 on the basis of the data of the information acquired by the sensors 5, 6; the storage devices 13a, 13b, 13c and the storage devices 14 for storing the data of the information acquired by the sensors 5, 6 and data of the control signals output from the integrated controller unit 2; the storage controller 15 for allocating and storing the data of the information acquired by the sensors 5, 6 and the data of the control signals output from the integrated controller unit 2 to and in the storage devices 13a, 13b, 13c and/or the storage devices 14, wherein the storage controller 15 generates parities corresponding to the allocated data and stores data of the parities in at least one of the storage devices. This enables implementation of a data recorder function without adding a new device and prevention of storage incapability due to a break of the network because the plurality of storage devices are distributed. Moreover, since the storage devices are distributed and the data are encoded, even if a failure occurs in the storage devices, lost information can be restored, thus being able to increase survivability of the stored data.
While the present application describes an exemplary embodiment and various examples, it should be understood that various features, aspects, and functionalities described in the embodiment are not limited in their applicability to the particular embodiment but instead can be applied alone or in various combinations to the embodiment. Therefore, numerous modifications that have not been exemplified are conceivable without departing from the technical scope disclosed in the specification of the present application. For example, at least one of the constituent components may be modified, added, or eliminated. Further at least one of the constituent components may be selected and combined with the other constituent elements.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/018507 | 5/7/2020 | WO |