WO2023223940A1

WO2023223940A1 - In-vehicle device, program, and information processing method

Info

Publication number: WO2023223940A1
Application number: PCT/JP2023/017775
Authority: WO
Inventors: 将史大場; 和弘平野
Original assignee: 住友電装株式会社
Priority date: 2022-05-19
Filing date: 2023-05-11
Publication date: 2023-11-23
Also published as: JP2023170679A

Abstract

Provided is an in-vehicle device, which is mounted on a vehicle and is communicably connected to an in-vehicle ECU using a CAN communication protocol, wherein the in-vehicle device comprises a control unit that performs control relating to communications with the in-vehicle ECU, the control unit detecting interrupt processing that occurs after transmission of data to the in-vehicle ECU and determining whether or not communication with the in-vehicle ECU is performed normally on the basis of the result of detection.

Description

In-vehicle device, program and information processing method

The present disclosure relates to an in-vehicle device, a program, and an information processing method.
This application claims priority based on Japanese Application No. 2022-082589 filed on May 19, 2022, and incorporates all the contents described in the said Japanese application.

Vehicles are equipped with a body ECU, which is an in-vehicle ECU that centrally controls body-related devices such as a wiper drive device, lighting devices inside and outside the vehicle, door lock devices, and power windows. Reference 1). The wiper drive device of Patent Document 1 includes a vehicle-mounted ECU (body ECU) and is driven by a control program applied to the vehicle-mounted ECU.

JP2017-224926A

An in-vehicle device according to an aspect of the present disclosure is an in-vehicle device that is installed in a vehicle and is communicably connected to an in-vehicle ECU using a CAN communication protocol, and includes a control unit that performs control regarding communication with the in-vehicle ECU. The control unit detects an interrupt process that occurs after data is transmitted to the in-vehicle ECU, and determines whether communication with the in-vehicle ECU is being performed normally based on the detection result.

1 is a schematic diagram illustrating the configuration of an in-vehicle system including an in-vehicle device and the like according to a first embodiment; FIG. FIG. 2 is a block diagram illustrating the internal configuration of an on-vehicle device. FIG. 3 is an explanatory diagram regarding detection of interrupt processing by the control unit of the in-vehicle device. 3 is a flowchart illustrating processing of a control unit of an in-vehicle device.

[Problems that this disclosure seeks to solve]
The in-vehicle ECU of Patent Document 1 has a problem in that it does not take into account the determination of whether processing related to communication with other devices is being performed normally.

An object of the present disclosure is to provide an in-vehicle device or the like that can determine whether processing related to communication with other devices is being performed normally.

[Effects of this disclosure]
According to one aspect of the present disclosure, it is possible to provide an in-vehicle device or the like that determines whether processing related to communication with other devices is being performed normally.

[Description of embodiments of the present disclosure]
First, embodiments of the present disclosure will be listed and described. Furthermore, at least some of the embodiments described below may be combined arbitrarily.

(1) An in-vehicle device according to an aspect of the present disclosure is an in-vehicle device that is installed in a vehicle and is communicably connected to an in-vehicle ECU using a CAN communication protocol, and controls control regarding communication with the in-vehicle ECU. The control unit detects an interrupt process that occurs after data is transmitted to the in-vehicle ECU, and determines whether communication with the in-vehicle ECU is being performed normally based on the detection result. judge.

In this aspect, when an in-vehicle device and a plurality of in-vehicle ECUs communicate using a CAN (Controller Area Network) communication protocol, each of the in-vehicle device and the in-vehicle ECUs function as a CAN node. When a process of transmitting data (CAN frame) from the vehicle-mounted device to the CAN bus via a communication unit such as a CAN transceiver is performed, the control unit of the vehicle-mounted device attempts to detect an interrupt process that occurs after the transmission. The interrupt process is defined in the specifications of the CAN communication process so that it occurs after the data is transmitted when the data is transmitted by the CAN. The control unit of the in-vehicle device determines whether communication between the in-vehicle device and the in-vehicle ECU is being performed normally based on the detection result of the interrupt process, that is, whether or not an interrupt process is detected. It is possible to efficiently determine whether processing related to communication with other devices is being performed normally. In this way, the control unit of the in-vehicle device performs communication processing related to data transmission and reception with the in-vehicle ECU using CAN, and monitors the presence or absence of interrupt processing in parallel with the communication processing, thereby increasing the reliability of CAN communication. It is possible to guarantee gender.

(2) In the in-vehicle device according to one aspect of the present disclosure, the interrupt processing includes a transmission completion interrupt and an error interrupt, and when the control unit detects the transmission completion interrupt, the control unit communicates with the in-vehicle ECU. is determined to be normal, and if neither the transmission completion interrupt nor the error interrupt is detected, the communication with the in-vehicle ECU is determined to be abnormal, and the initialization processing of the control unit is performed. conduct.

In this aspect, interrupt processing that may occur in response to the transmission of data (CAN frame) from the in-vehicle device that is the source node includes a transmission completion interrupt and an error interrupt. A transmission completion interrupt is an interrupt process that occurs when data (CAN frame) is successfully transmitted. An error interrupt is an interrupt process that occurs when transmitted data is received by, for example, loopback processing, and a difference occurs between the received data and the transmitted data. Such data differences occur, for example, due to a failure in a communication unit such as a CAN transceiver, or a failure such as a short circuit (ground fault) in a communication line such as a CAN bus. In other words, an error interrupt occurs when a bit error (bit inversion) in data (CAN frame) or physical bus error occurs due to an event that occurs in the physical layer that is lower than the communication unit such as a CAN transceiver. becomes. Further, the error interrupt may include, for example, an ACK error or an error such as arbitration lost. The control unit operates to generate an interrupt process such as a transmission completion interrupt or an error interrupt each time data is transmitted by executing a CAN communication control program. The control unit also periodically, regularly, or constantly monitors the occurrence of the interrupt process, and if it detects a transmission completion interrupt, it indicates that the communication with the in-vehicle ECU is normal (communication has completed normally). ). If the control unit does not detect either a transmission completion interrupt or an error interrupt, an abnormality occurs in the execution state of the CAN communication control program (data cannot be sent due to a stuck state), and communication with the in-vehicle ECU is disabled. It is determined that there is an abnormality (the in-vehicle device is abnormal). In other words, if the process that executes the CAN communication control program is in a hung state, for example, and data transmission is not possible due to state fixation in software processing, both the transmission completion interrupt and error interrupt processing will not be detected. What is not done becomes. In this case, the control unit determines that a communication abnormality has occurred due to an abnormality in the process that executes the communication control program, and performs recovery processing for the communication abnormality in order to initialize its own unit (control unit). can be done efficiently. The initialization process of the control unit includes, for example, restarting the CAN communication control program, resetting (restarting) the control unit itself, or resetting (restarting) the in-vehicle device itself, that is, software reset ( Initialization), hardware reset (initialization), or both software and hardware reset (initialization) may be performed. In this way, even if actuators such as wipers connected to multiple in-vehicle ECUs to which data (CAN frames) are sent temporarily stop working due to a communication error, recovery processing is performed. This allows the actuator to be efficiently restarted.

(3) In the in-vehicle device according to one aspect of the present disclosure, data is transmitted to the in-vehicle ECU at a predetermined transmission cycle, and the control unit transmits data to the in-vehicle ECU at a predetermined period based on the transmission cycle. If neither the transmission completion interrupt nor the error interrupt is detected, it is determined that the communication with the in-vehicle ECU is abnormal.

In this aspect, an in-vehicle device that is a transmission source node transmits data (CAN frame) at a predetermined transmission cycle to a plurality of in-vehicle ECUs that are destination nodes. Matters regarding the transmission cycle are stored in the storage unit of the in-vehicle device, and the CAN-ID (message ID), transmission order, and transmission time interval (transmission cycle) of the data to be transmitted (CAN frame) are defined. It is (included). The information regarding the transmission cycle may be stored in the storage unit of the vehicle-mounted device in a table format (transmission cycle table), such as the transmission cycle for each CAN-ID. The control unit of the in-vehicle device refers to the transmission cycle information stored in the storage unit, and detects either a transmission completion interrupt or an error interrupt in a predetermined period according to the defined transmission cycle. Determine whether or not. The predetermined period corresponds to a detection unit period when detecting an interrupt process, and is calculated as a value (T x n) obtained by multiplying the transmission cycle (T) by a predetermined number (n), for example. It may be something. When the predetermined number (n) is set to 3, if any interrupt processing cannot be detected over three cycles (number of cycles: 3), it can be determined that there is an abnormality. As a result, even if interrupt processing cannot be detected (missed) due to an accidental event, the detection unit period (predetermined) when detecting interrupt processing corresponds to multiple transmission cycles. By setting the period), it is possible to prevent erroneous judgments due to such omissions. Further, the detection unit period (predetermined period) when detecting an interrupt process may be set by taking into account a tolerance with respect to the transmission period (T). The tolerance for the transmission cycle (T) is a difference that occurs within the allowable range according to the product specifications of the in-vehicle device. For example, it is set as ±10% with respect to the design value of the transmission cycle (T). It may be. In this case, the detection unit period (predetermined period) may be set as transmission cycle (T) x predetermined number (number of cycles: n) x (1.01). The control unit of the in-vehicle device continues transmitting until a detection unit period (predetermined period) set based on the transmission cycle elapses, starting from the point in time when the transmission completion interrupt or error interrupt detected immediately before is detected (starting point). If neither a completion interrupt nor an error interrupt is detected, it may be determined that the communication with the on-vehicle ECU is abnormal. In this way, a predetermined period corresponding to the transmission cycle of data (CAN frame) from the in-vehicle device (source node) to the in-vehicle ECU (destination node) is set as the period for making the determination (detection unit period). Accordingly, the determination accuracy can be improved.

(4) In the in-vehicle device according to one aspect of the present disclosure, there are multiple types of data transmitted to the in-vehicle ECU at the transmission cycle, and the predetermined period is determined based on the number of types and the transmission cycle. It will be done.

In this aspect, there are multiple types of data (CAN frames) transmitted from the in-vehicle device (source node) to the in-vehicle ECU (destination node). The type may be determined by, for example, CAN-ID (message ID). That is, the data (CAN frame) transmitted from the in-vehicle device to the in-vehicle ECU includes a plurality of types of data (CAN frames) with different CAN-IDs, for example, two types of CAN-IDs such as 101 and 102. In this case, the detection unit period (predetermined period) when detecting interrupt processing is the number of types of data (CAN frame) (number of types of CAN-ID) and the data for each type (for each CAN-ID). It may be determined based on the transmission period (T) in each. For example, when setting a detection unit period (predetermined period) corresponding to multiple periods (n periods) in any type of data (CAN frame), set the number of periods (n periods) to the transmission period (T). The detection unit period (predetermined period) may be derived (T×n/k) by dividing the multiplied value by the number of data types (k). Furthermore, the value may be a value (T×n×(1+D/100)/k) in which a tolerance (D%: for example, ±10%, etc.) during transmission is added to the value. In this way, in order to determine the number of types of data (CAN frames) sent from the in-vehicle device (source node) to the in-vehicle ECU (destination node), and the predetermined period depending on the transmission cycle for each type of data. By setting the period (detection unit period) to , it is possible to improve the determination accuracy.

(5) The in-vehicle device according to one aspect of the present disclosure communicates with the in-vehicle ECU via a CAN bus, and includes a communication unit to which the CAN bus is connected, and the control unit is configured to respond to the error interrupt. If detected, it is determined that the communication with the vehicle-mounted ECU is abnormal, and initialization processing of the communication unit is performed.

In this aspect, when the control unit of the in-vehicle device detects an error interrupt, it determines that communication with the in-vehicle ECU is abnormal (communication has ended abnormally) due to a failure of a communication unit such as a CAN transceiver, Performs initialization processing of the communication unit (CAN transceiver). The initialization process of the communication unit (CAN transceiver) may include, for example, performing a hardware reset (initialization) by cutting off and restarting power to the communication unit. Thereby, the communication unit can be brought into a normal state, and communication with the vehicle-mounted ECU can be restored to a normal state. If the control unit of the in-vehicle device continues to detect error interrupts even though the initialization process of the communication unit has been performed a predetermined number of times or more, the control unit of the in-vehicle device detects a short circuit (ground) in the communication line such as the CAN bus. It may be determined that a failure (physical bus error) such as a physical bus error has occurred, and the determination result may be stored in a storage unit and output to an HMI (Human Machine Interface) device such as a display.

(6) An information processing method according to an aspect of the present disclosure includes a computer that is installed in a vehicle, is communicably connected to an in-vehicle ECU using a CAN communication protocol, and controls communication with the in-vehicle ECU. An interrupt process that occurs after data is transmitted to an on-vehicle ECU is detected, and based on the detection result, a process is executed to determine whether communication with the on-vehicle ECU is being performed normally.

In this aspect, it is possible to provide an information processing method that causes a computer to function as an in-vehicle device that determines whether processing related to communication with other devices is being performed normally.

(7) A program according to an aspect of the present disclosure is installed in a vehicle, is communicably connected to an in-vehicle ECU using a CAN communication protocol, and is transmitted to a computer that controls communication with the in-vehicle ECU. An interrupt process that occurs after data is transmitted to the ECU is detected, and based on the detection result, a process is executed to determine whether communication with the in-vehicle ECU is being performed normally.

In this aspect, it is possible to provide a program that causes a computer to function as an in-vehicle device that determines whether processing related to communication with other devices is being performed normally.

[Details of embodiments of the present disclosure]
The present disclosure will be specifically described based on drawings showing embodiments thereof. An in-vehicle device 1 and the like according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all changes within the meaning and scope equivalent to the scope of the claims.

(Embodiment 1)
Hereinafter, embodiments will be described based on the drawings. FIG. 1 is a schematic diagram illustrating the configuration of an in-vehicle system S including an in-vehicle device 1 and the like according to the first embodiment. FIG. 2 is a block diagram illustrating the internal configuration of the in-vehicle device 1. As shown in FIG. The in-vehicle system S is composed of an in-vehicle device 1 mounted on a vehicle C and a plurality of in-vehicle ECUs 2, and these in-vehicle devices 1 and each of the plurality of in-vehicle ECUs 2 (Electronic Control Units) are connected to a communication line 4 (CAN bus). communicably connected. The in-vehicle device 1 and the in-vehicle ECU 2 are configured to transmit and receive data (CAN frames) using a CAN (Controller Area Network) communication protocol, and the in-vehicle device 1 and the in-vehicle ECU 2 function as CAN nodes.

An on-vehicle load 3 (actuator) such as a lamp, a door mirror, or a wiper is communicably connected to each of the on-vehicle ECUs 2. These in-vehicle ECUs 2 receive data (CAN frames) transmitted from the in-vehicle device 1, and depending on the received data, control the in-vehicle loads 3 (actuators) directly connected to their own ECU (in-vehicle ECU 2 itself). Performs drive control.

The in-vehicle device 1 is configured to detect a transmission completion interrupt or an error interrupt each time after transmitting data to the in-vehicle ECU 2. Although the details will be described later, if the in-vehicle device 1 does not detect any interrupt processing, such as a transmission completion interrupt or an error interrupt, after transmitting data to the in-vehicle ECU 2 until a predetermined period has elapsed, the state will be fixed in the software processing. It is determined that a communication abnormality has occurred due to, etc., and the software and hardware related to CAN communication are initialized.

The in-vehicle device 1 includes a control section 11, a storage section 12, and a communication section 13. The in-vehicle device 1 may function, for example, as a body ECU that performs overall control of body-related actuators. Alternatively, the in-vehicle device 1 may be configured with a central control device such as a vehicle computer, and may function as an integrated ECU that performs integrated control of the entire vehicle C.

The control unit 11 is composed of a CPU (Central Processing Unit), an MPU (Micro Processing Unit), etc., and performs various controls by reading and executing programs (program products) and data stored in advance in the storage unit 12. Performs processing, arithmetic processing, etc. The control unit 11 may be configured by being packaged with a microcomputer or the like together with the storage unit 12 and the like. The control unit 11 is not limited to a software processing unit such as a CPU that performs software processing, but may also be a hardware processing unit such as an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or an SOC (System on Chip). It may include a hardware processing unit that performs various control processing, calculation processing, and the like.

The storage unit 12 is composed of a volatile memory element such as a RAM (Random Access Memory), or a nonvolatile memory element such as a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable ROM), or a flash memory. A program P (program product) or data of the in-vehicle device 1 is stored. The program P (program product) stored in the storage unit 12 may be a program P (program product) read from a recording medium M readable by the in-vehicle device 1. Alternatively, the program P (program product) may be downloaded from an external computer (not shown) connected to a communication network (not shown) and stored in the storage unit 12. The storage unit 12 stores items related to the transmission cycle including various parameters used when performing CAN communication, such as the CAN-ID (message ID) to be transmitted, the order of transmission, and the time interval for transmission (transmission cycle). ing. The matters related to the transmission cycle may be stored in the storage unit 12 in a table format (transmission cycle table) including the transmission cycle and the like as management items.

The communication unit 13 is composed of a CAN transceiver, which is an input/output interface using a communication protocol such as CAN. A communication line 4 (CAN bus) having a bus configuration is connected to the communication unit 13 (CAN transceiver), and CAN communication is performed between the in-vehicle device 1 and the in-vehicle ECU 2 via the communication line 4.

Similarly to the in-vehicle device 1, each of the in-vehicle ECUs 2 includes a control section, a storage section, and a communication section (CAN transceiver). A vehicle load 3 (actuator) such as a wiper is directly connected to each of these vehicle ECUs 2 via a serial cable or the like. The on-vehicle ECU 2 drives an on-vehicle load 3 (actuator) directly connected to its own ECU (on-vehicle ECU 2 itself) based on data received from the on-vehicle device 1 through CAN communication.

FIG. 3 is an explanatory diagram regarding detection of interrupt processing by the control unit 11 of the in-vehicle device 1. This explanatory diagram shows the states of the communication line 4 and the vehicle-mounted device 1 during the elapsed time indicated by the horizontal axis. On top of that, we will discuss transmission completion interrupts, error interrupts, and time monitoring (monitoring processing that involves time measurement) for detecting these interrupt processes, which are processes performed by the control unit 11 such as a microcomputer installed in the in-vehicle device 1. will also be schematically explained.

Interrupt processing that occurs after transmitting data (CAN frame) includes transmission completion interrupts and error interrupts, and is defined in the specifications of communication processing by CAN to occur after transmitting data when transmitting data by CAN. ing. The control unit 11 (the process that executes the CAN communication control program) of the in-vehicle device 1 receives the transmitted data through loopback processing, etc., and if a difference occurs between the received data and the transmitted data ( If a bit error occurs), an error interrupt is generated, and if no difference occurs, a transmission completion interrupt is generated. An error interrupt may be generated not only when a bit error occurs, but also when an ACK error, arbitration lost, or the like occurs. In this way, if no bit error, ACK error, arbitration lost, etc. occur, the CAN communication is determined to be normal, and if a difference occurs, the CAN communication is determined to be abnormal (a communication error has occurred). be done.

When both the communication line 4 and the vehicle-mounted device 1 are in a normal state (case), the vehicle-mounted device 1 detects a transmission completion interrupt (indicated by a solid line) each time after transmitting data to the vehicle-mounted ECU 2. The in-vehicle device 1 performs a process of re-measuring the time (predetermined period) for determining an abnormality (re-measuring the time due to the occurrence of the transmission completion interrupt) using the detected transmission completion interrupt as a starting point. That is, upon detection of a transmission completion interrupt, the elapsed time for time monitoring is set to 0 (0 cleared: timer reset).

The in-vehicle device 1 detects an error interrupt when the communication line 4 becomes temporarily abnormal, such as when noise or the like occurs on the communication line 4. In this case, the transmission completion interrupt that would normally be detected is not detected (does not occur). In this explanatory diagram, the transmission completion interrupt that was not detected (did not occur) is indicated by a broken line. The in-vehicle device 1 performs a process of re-measuring the time (predetermined period) for determining an abnormality (re-measuring the time due to the occurrence of an error) using the time of detection of the detected error interrupt as a starting point. That is, upon detection of an error interrupt, the elapsed time for time monitoring is set to 0 (0 cleared: timer reset).

In this explanatory diagram, after the in-vehicle device 1 detects a transmission completion interrupt (indicated by a solid line), if, for example, an abnormality occurs in software processing (unable to transmit due to stuck state), the in-vehicle device 1 detects a transmission completion interrupt and There is a period in which neither error interrupt occurs (is not detected). During this period, if the communication line 4 and in-vehicle device 1 were normal, multiple transmission completion interrupts (indicated by broken lines) would be detected, but not only these transmission completion interrupts but also error interrupts are not detected. becomes.

The in-vehicle device 1 sets a predetermined period according to the transmission cycle to the in-vehicle ECU 2 as a period for making a determination (detection unit period), and generates a transmission completion interrupt and an error interrupt in the predetermined period (detection unit period). If not detected, it is determined that transmission failure (abnormality) due to state fixation or the like has occurred. The period (detection unit period) for performing the determination corresponds to the expiration time from the start of measuring the passage of time in a timer used when performing the determination process. The expiration time of the timer defines the time from the occurrence of a failure to the execution of recovery processing. Based on the regulations, it becomes possible to perform recovery processing before other in-vehicle ECUs 2 detect a failure in the in-vehicle device 1 (own device). Furthermore, it is possible to perform recovery processing before a failure of the in-vehicle device 1 occurs. Further, it is possible to absorb errors in the data transmission cycle and make a determination. Further, by setting one transmission cycle (one cycle) as the lower limit of the expiration time (detection unit period) of the timer, it is possible to suppress the occurrence of erroneous determination.

The predetermined period (detection unit period) may be set by taking into account the tolerance (±D%) for the transmission cycle (T) of data (CAN frame). Furthermore, the predetermined period (detection unit period) may be set corresponding to a plurality of periods (n). Furthermore, the predetermined period (detection unit period) may be set depending on the number (k) of types of data (CAN frames). At this time, if the transmission period (T) is the same for all types of data regardless of the data type, the predetermined period (detection unit period) is calculated using the formula {T×n×(1+D/100)}/k. It may also be calculated by

The type of data (CAN frame) transmitted by the in-vehicle device 1 is determined (classified) by, for example, CAN-ID (message ID). When the in-vehicle device 1 transmits CAN frames with different CAN-IDs, the number of CAN-IDs corresponds to the number of data types (number of types). For example, if the CAN-ID of the CAN frame transmitted by the in-vehicle device 1 consists of 101 and 102, the number of data types (number of types) is two (two types). The transmission cycle of the CAN frame for each of these different CAN-IDs may be the same cycle (T), or may be different for each CAN-ID (for each type of data). For example, if the period (T) is 100 ms, the number of periods is 3, the number of data types is 2, and the tolerance at the time of transmission is ±10%, the detection unit period (predetermined period ) is 165ms {165=(100×3/2)×(1+0.1)}.

The in-vehicle device 1 executes a recovery process (reset) in order to resolve the inability to transmit (abnormality) due to a stuck state or the like. The recovery process (reset) includes a process of initializing software and hardware related to CAN communication. The in-vehicle device 1 is restarted by executing the recovery process, and recovers (transitions) from an abnormal state to a normal state.

FIG. 4 is a flowchart illustrating the processing of the control unit 11 of the in-vehicle device 1. The control unit 11 of the in-vehicle device 1 monitors interrupt processing by performing the following processing, for example, when the vehicle C is activated or stopped. The control unit 11 of the in-vehicle device 1 regularly performs communication processing regarding transmission and reception of data (CAN frames) with the in-vehicle ECU 2 using the CAN communication protocol. Then, the control unit 11 of the in-vehicle device 1 performs processing such as monitoring of the interrupt processing that occurs due to the CAN communication processing.

The control unit 11 of the in-vehicle device 1 determines whether a transmission completion interrupt has been detected (S101). In determining whether or not a transmission completion interrupt has been detected, the control unit 11 of the in-vehicle device 1 determines whether or not an interrupt signal indicating a transmission completion interrupt has been transmitted from the process that executes the CAN communication control program. It may also be something that makes a determination. That is, in the control unit 11 of the in-vehicle device 1, a process that executes a CAN communication control program and a process that executes a monitoring process are generated, and the process that executes the monitoring process executes the CAN communication control program. When a signal (transmission completion interrupt signal) sent by the executing process is received, it may be determined that a transmission completion interrupt has been detected. Alternatively, when transmitting data (CAN frame), the control unit 11 of the in-vehicle device 1 performs post-processing to attempt to obtain data or a signal regarding whether or not a transmission completion interrupt has occurred, and based on the result of the post-processing, , it may be determined whether or not a transmission completion interrupt has been detected.

If it is determined that a transmission completion interrupt has been detected (S101: YES), the control unit 11 of the in-vehicle device 1 determines that communication with the in-vehicle ECU 2 has been successfully completed (S102). The transmission completion interrupt is an interrupt process that occurs when data is normally transmitted from the in-vehicle device 1. When determining that the transmission completion interrupt has been detected, the control unit 11 of the in-vehicle device 1 determines that the CAN communication with the in-vehicle ECU 2 has been successfully completed.

The control unit 11 of the in-vehicle device 1 stores time information such as a timestamp or time indicating the time when the transmission completion interrupt was detected (the transmission completion interrupt detection time) in the storage unit 12. The transmission completion interrupt detection time information (transmission completion interrupt detection time) stored in the storage unit 12 is used as the starting point (timer reset) of the transmission cycle when transmitting the next data (CAN frame). The control unit 11 of the in-vehicle device 1 performs a process of re-measuring time such as a transmission cycle upon detection (occurrence) of a transmission completion interrupt.

If it is determined that a transmission completion interrupt has not been detected (S101: NO), the control unit 11 of the vehicle-mounted device 1 determines whether or not an error interrupt has been detected (S103). The error interrupt is an interrupt process that occurs when data is not transmitted normally from the in-vehicle device 1, and the transmitted data is received by loopback processing, etc., and the received data and the transmitted data are This is an interrupt process that occurs when a difference (bit error) occurs between the two, an ACK error, arbitration lost, or the like occurs.

When the control unit 11 of the vehicle-mounted device 1 determines that an error interrupt has been detected, it determines that the CAN communication with the vehicle-mounted ECU 2 is abnormal (a communication error has occurred). When determining whether or not an error interrupt has been detected, the control unit 11 of the in-vehicle device 1 makes the determination based on whether or not an interrupt signal indicating an error interrupt has been transmitted from the process that executes the CAN communication control program. It may be something you do. That is, in the control unit 11 of the in-vehicle device 1, a process that executes a CAN communication control program and a process that executes a monitoring process are generated, and the process that executes the monitoring process executes the CAN communication control program. If a signal (error interrupt signal) sent by the executing process is received, it may be determined that an error interrupt has been detected. Alternatively, when transmitting data (CAN frame), the control unit 11 of the in-vehicle device 1 performs post-processing to attempt to obtain data or signals regarding the occurrence of an error interrupt, and based on the result of the post-processing, It may be determined whether or not an error interrupt has been detected.

If it is determined that an error interrupt has been detected (S103: YES), the control unit 11 of the in-vehicle device 1 determines that communication with the in-vehicle ECU 2 has ended abnormally (S104). When the control unit 11 of the in-vehicle device 1 determines that an error interrupt has been detected, a failure such as noise generation or a short circuit (ground fault) has occurred in the communication line 4 (fault) or the communication unit 13 (CAN transceiver). However, it may be determined that the communication with the in-vehicle ECU 2 is abnormal.

The control unit 11 of the vehicle-mounted device 1 stores time information such as a timestamp or time indicating the time when the error interrupt was detected (the time of error interrupt detection) in the storage unit 12. The error interrupt detection time information (error interrupt detection time) stored in the storage unit 12 is used as the starting point (timer reset) of the transmission cycle when transmitting the next data (CAN frame), and is used as the starting point (timer reset) for transmitting the next data (CAN frame). The control unit 11 performs a process of re-measuring time such as a transmission cycle upon detection (occurrence) of an error interrupt.

The control unit 11 of the in-vehicle device 1 initializes the communication unit 13 (S105). When the control unit 11 of the in-vehicle device 1 detects an error interrupt, it performs an initialization process for the communication unit 13 (CAN transceiver). The initialization process for the communication unit 13 (CAN transceiver) may include, for example, performing a hardware reset (initialization) by cutting off and restarting power to the communication unit 13. By resetting the communication unit 13 in this manner, the communication unit 13 can be transitioned to a normal state, and communication with the in-vehicle ECU 2 can be restored to a normal state. The control unit 11 of the in-vehicle device 1 may store history information including the date and time when the communication unit 13 was initialized in the storage unit 12. After executing the process in S105, the control unit 11 of the in-vehicle device 1 performs a loop process to execute the process from S101 again.

In the present embodiment, the control unit 11 of the in-vehicle device 1 initializes the communication unit 13 each time an error interrupt is detected in step S105, but the invention is not limited to this. The control unit 11 of the in-vehicle device 1 may continue monitoring the interrupt processing without initializing the communication unit 13 even when an error interrupt is detected. Error interrupts can also occur when noise occurs in the communication line 4 or when a temporary failure occurs due to accumulation of electric charge in the communication section 13. It is possible that it will be restored. Therefore, the control unit 11 of the in-vehicle device 1 may initialize the communication unit 13 when error interrupts continue to be detected, such as when error interrupts are detected a plurality of times in succession.

If it is determined that an error interrupt has not been detected (S103: NO), the control unit 11 of the in-vehicle device 1 determines whether a predetermined period of time has elapsed (S1031). When determining that no error interrupt has been detected, the control unit 11 of the vehicle-mounted device 1 determines whether a predetermined period of time has elapsed since the most recently detected transmission completion interrupt or error interrupt. The predetermined period is a predetermined period according to the transmission cycle of data transmitted from the in-vehicle device 1 to the in-vehicle ECU 2, and corresponds to a period for making a determination (detection unit period). The period for making the determination (detection unit period) may be set (derived) based on the data transmission cycle, the number of cycles, the tolerance of the transmission cycle, and the number of types of data. The detection unit period may be defined in a configuration file or the like stored in the storage unit 12. If it is determined that the predetermined period has not elapsed (S1031: NO), the control unit 11 of the in-vehicle device 1 performs a loop process to execute the process from S101 again.

If it is determined that the predetermined period has elapsed (S1031: YES), the control unit 11 of the vehicle-mounted device 1 determines that the vehicle-mounted device 1 is abnormal (S1032). This process is executed when a transmission completion interrupt is not detected in the branch process of S101 (S101: NO), so if it is determined that an error interrupt is not detected within a predetermined period, an error interrupt is executed. In addition, the transmission completion interrupt is also not detected. When the predetermined period of time has elapsed in this way, the control unit 11 of the in-vehicle device 1 determines that neither the transmission completion interrupt nor the error interrupt has been detected in the predetermined period (detection unit period) corresponding to multiple cycles. do.

If the control unit 11 of the in-vehicle device 1 does not detect any interrupt processing, either a transmission completion interrupt or an error interrupt, an abnormality occurs in the execution state of the CAN communication control program (data transmission is not possible due to a stuck state), and the in-vehicle device Device 1 is determined to be abnormal. In other words, the control unit 11 of the in-vehicle device 1 is unable to send data due to a hang state in the process that executes the CAN communication control program, a stuck state in software processing, and a transmission completion interrupt and an error interrupt. It is determined that none of the interrupt processing has occurred.

The control unit 11 of the in-vehicle device 1 initializes the control unit 11 (S1033). The control unit 11 of the in-vehicle device 1 initializes the communication unit 13 (S1034). The control unit 11 of the in-vehicle device 1 initializes the control unit 11 by restarting the CAN communication control program, restarting the control unit 11 itself, or restarting the in-vehicle device 1 itself including the communication unit 13, for example. conduct. The control unit 11 of the in-vehicle device 1 may perform each of these resets (restarts) in stages. The control unit 11 of the in-vehicle device 1 may perform software reset (initialization), hardware reset (initialization), or both software and hardware reset (initialization). The control unit 11 of the in-vehicle device 1 may initialize the communication unit 13 after initializing the control unit 11 or simultaneously with the initialization. The initialization of the communication unit 13 in this process (S1034) may be the same process as S105. If the restart of the in-vehicle device 1 itself described as an example of initialization of the control unit 11 includes initialization of both the control unit 11 and the communication unit 13, the processes of S1033 and S1034 are performed at substantially the same timing. It will be held in

By performing such initialization, for example, in an extremely small defect window, that is, in a processing unit period that is a relatively short period, CAN Even if communication is interrupted and vehicle C functions such as actuators (on-vehicle loads 3) such as wipers connected to the on-vehicle ECU 2 stop operating, recovery is possible. The control unit 11 of the in-vehicle device 1 may store history information including the date and time when the control unit 11 was initialized in the storage unit 12. After executing the process of S1033, the control unit 11 of the vehicle-mounted device 1 performs a loop process to execute the process from S101 again.

The embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The scope of the present invention is indicated by the scope of the claims, not the meaning described above, and is intended to include meanings equivalent to the scope of the claims and all changes within the scope.

Multiple claims described in the scope of claims may be combined with each other regardless of the citation format. The claims may include multiple dependent claims that are dependent on multiple claims. Multiple dependent claims may be written that are dependent on multiple dependent claims. Even if a multiple dependent claim that is dependent on a multiple dependent claim is not written, this does not limit the writing of the multiple dependent claim that is dependent on the multiple dependent claim.

C Vehicle
S Vehicle-mounted system 1 Vehicle-mounted device 11 Control unit 12 Storage unit M Recording medium P Program (program product)
13 Communication department (CAN transceiver)
2 In-vehicle ECU
3 On-vehicle load 4 Communication line (CAN bus)

Claims

An in-vehicle device installed in a vehicle and communicably connected to an in-vehicle ECU using a CAN communication protocol,
comprising a control unit that controls communication with the in-vehicle ECU,
The control unit includes:
detecting an interrupt process that occurs after data is transmitted to the in-vehicle ECU;
An in-vehicle device that determines whether communication with the in-vehicle ECU is being performed normally based on the detection result.
The interrupt processing includes a transmission completion interrupt and an error interrupt,
The control unit includes:
If the transmission completion interrupt is detected, determining that communication with the in-vehicle ECU is normal;
The in-vehicle device according to claim 1, wherein if neither the transmission completion interrupt nor the error interrupt is detected, the communication with the in-vehicle ECU is determined to be abnormal, and initialization processing of the control unit is performed. Device.
Transmission of data to the in-vehicle ECU is performed at a predetermined transmission cycle,
The control unit determines that communication with the in-vehicle ECU is abnormal if it does not detect any of the transmission completion interrupt and the error interrupt during a predetermined period based on the transmission cycle. The in-vehicle device according to item 2.
There are multiple types of data transmitted to the in-vehicle ECU at the transmission cycle,
The vehicle-mounted device according to claim 3, wherein the predetermined period is determined based on the number of types and the transmission cycle.
Communication with the in-vehicle ECU is performed via a CAN bus,
comprising a communication unit to which the CAN bus is connected,
The control unit, when detecting the error interrupt, determines that communication with the in-vehicle ECU is abnormal and performs initialization processing of the communication unit. in-vehicle equipment.
A computer installed in a vehicle, communicably connected to an in-vehicle ECU using a CAN communication protocol, and controlling communication with the in-vehicle ECU;
detecting an interrupt process that occurs after data is transmitted to the in-vehicle ECU;
An information processing method that executes a process of determining whether communication with the in-vehicle ECU is being performed normally based on the detection result.
A computer installed in a vehicle, communicably connected to an in-vehicle ECU using a CAN communication protocol, and controlling communication with the in-vehicle ECU;
detecting an interrupt process that occurs after data is transmitted to the in-vehicle ECU;
A program that executes a process of determining whether communication with the in-vehicle ECU is being performed normally based on the detection result.