JP2006140739A - Communication synchronization device, system, method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress useless communication processing at start and to dispense with the maintenance of an existing ECU even when a new ECU is connected to a network. <P>SOLUTION: A communication synchronization device recalculates communication mask time, based on communication formation time which is measuring time from communication start up to communication formation and starts communication processing by using the communication mask time at the succeeding start. Moreover, the communication mask time is calculated on the basis of margin time for coping with measuring errors and dispersion in the operation of respective ECUs 1, 2, shortening time for coping with the shortening of the communication mask time and maximum mask time and minimum mask time for preventing the communication mask time from becoming an abnormal value. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a communication synchronization device, a communication synchronization system, a communication synchronization method, and a communication synchronization program that perform communication synchronization control at the start of communication, and in particular, learns the time until communication is established and automatically adjusts the communication start timing. By doing so, it is possible to eliminate unnecessary communication processing at the time of start-up, and communication that does not require maintenance work to adjust the communication start timing even when a new device is connected to the network The present invention relates to a synchronization device, a communication synchronization system, a communication synchronization method, and a communication synchronization program.

  2. Description of the Related Art Conventionally, in a moving body such as a vehicle, a plurality of electronic control units (ECUs) that control sensors and actuators are connected to each other via an in-vehicle LAN (Local Area Network) to control the entire vehicle.

  These ECUs are activated when the driver operates the ignition key to “ON”, and start communication processing in order to establish mutual communication. When communication between the ECUs is established, all ECUs are operable. Therefore, it is necessary to quickly establish such communication.

  For example, Patent Document 1 discloses an invention in which a master ECU is selected from a plurality of ECUs, and the master ECU performs startup processing of other ECUs, thereby shortening the communication establishment time between the ECUs as a whole. Has been.

Japanese Patent No. 3478656

  However, even if this Patent Document 1 is used, the performance of each ECU varies, and depending on the selection of the master ECU, the communication establishment time may not be shortened efficiently. In addition, since the time from when each ECU starts the communication process to when the communication is established is different, a wasteful communication process occurs before the communication is established.

  In order to suppress the occurrence of this wasteful communication, it is also conceivable that each ECU holds a communication mask time for adjusting the time from when each ECU is activated until the communication process is started. That is, each ECU attempts to suppress useless communication processing at the time of activation by starting communication processing after the set communication mask time has elapsed. However, even when such an adjustment time is held, when a new ECU is added to the in-vehicle LAN, it is necessary to maintain the communication mask time held by another ECU.

  Therefore, efficient communication synchronization can be performed by suppressing unnecessary communication processing at the start of each ECU, and maintenance work is required even when a new ECU is added to the in-vehicle LAN. It is a big problem how to realize an ECU that does not. Such a problem is not limited to the ECU, but is similarly a problem that occurs in a communication apparatus that is connected to a network and communicates with each other.

  The present invention has been made to solve the above-described problems caused by the prior art, and can suppress unnecessary communication processing when each ECU is activated, and a new ECU is connected to the network. Even if it is a case, it aims at providing the communication synchronization apparatus, the communication synchronization system, the communication synchronization method, and the communication synchronization program which do not need to maintain existing ECU.

  In order to solve the above-described problems and achieve the object, the communication synchronization device according to the first aspect of the present invention is a communication synchronization device that performs communication synchronization control at the start of communication, and communication is established from the start of communication to the establishment of communication. Measuring means for measuring time; calculation means for calculating a communication mask time representing a non-communication time from activation to communication start based on the communication establishment time; and storage for storing the communication mask time calculated by the calculation means And a communication means for reading out the communication mask time from the storage means and starting communication when the communication mask time elapses after the storage means stores the communication mask time. And

  According to a second aspect of the present invention, there is provided a communication synchronization apparatus according to the first aspect, wherein the calculation means adds a new communication establishment time to the communication mask time read out from the storage means. The communication mask time is calculated.

  According to a third aspect of the present invention, there is provided the communication synchronization apparatus according to the first or second aspect, wherein the calculation means includes the communication establishment time and a predetermined length in the communication mask time read from the storage means. A new communication mask time is calculated by adding the times.

  The communication synchronization device according to a fourth aspect of the present invention is the communication synchronization device according to the first, second, or third aspect, wherein the calculation means reads the communication mask read from the storage device when the communication establishment time is zero. A new communication mask time is calculated by subtracting a predetermined length of time from the time.

  Further, in the communication synchronization device according to the invention of claim 5, in the invention of claim 4, the storage means stores a counter representing that the activation with the communication establishment time being 0 is continuously performed, The calculation means calculates a new communication mask time by subtracting a predetermined length of time from the communication mask time read from the storage device only when the counter exceeds a predetermined number of times. Features.

  According to a sixth aspect of the present invention, there is provided the communication synchronizer according to any one of the first to fifth aspects, wherein the storage means includes a minimum mask time representing a minimum value of the communication mask time, and the communication mask time. A maximum mask time representing a maximum value of the communication mask time, and when the calculated communication mask time is smaller than the minimum mask time, the calculation means sets the communication mask time as the minimum mask time, and calculates the communication mask time. Is greater than the maximum mask time, the communication mask time is set as the maximum mask time.

  According to a seventh aspect of the present invention, there is provided the communication synchronizer according to any one of the first to fifth aspects, wherein the storage means includes a minimum mask time representing a minimum value of the communication mask time, and the communication mask time. The communication means stores the communication mask time as the minimum mask time when the read communication mask time is smaller than the minimum mask time, and the read communication mask time. The communication mask time is set as the maximum mask time when it is larger than the maximum mask time.

  According to an eighth aspect of the present invention, there is provided the communication synchronizer according to any one of the first to seventh aspects, wherein the communication means has passed the communication mask time read from the storage means and the measurement has been performed. The communication monitoring process is started when the communication establishment time measured by the means has elapsed.

  According to a ninth aspect of the present invention, there is provided a communication synchronization system that is mounted on a mobile body and includes an electronic control unit including a communication synchronization device that performs communication synchronization control at the start of communication, and a plurality of the electronic control units connected to each other. Each communication synchronization device includes a measuring means for measuring a communication establishment time from the start of communication to the establishment of communication, and a communication mask representing a non-communication time from the start to the start of communication Calculating means for calculating a time based on the communication establishment time; storage means for storing the communication mask time calculated by the calculating means; and storing the memory mask at startup after the storage means stores the communication mask time. Communication means for reading the communication mask time from the means and starting communication when the communication mask time elapses.

  A communication synchronization system according to a tenth aspect of the present invention is the communication synchronization system according to the ninth aspect, wherein when the electronic control unit including a communication synchronization device not provided with the storage means is connected to the network, the communication synchronization system is provided. The apparatus notifies the communication synchronization apparatus not provided with the storage means of the communication mask time held by the storage means.

  The communication synchronization method according to the invention of claim 11 is a communication synchronization method for performing communication synchronization control at the start of communication, measuring a communication establishment time from communication start to communication establishment, A calculation step of calculating a communication mask time representing a non-communication time until the start based on the communication establishment time, a storage step of storing the communication mask time calculated by the calculation step, and the storage step of the communication mask time A communication step of reading out the communication mask time from the storage step and starting communication when the communication mask time has elapsed.

  The communication synchronization program according to the invention of claim 12 is a communication synchronization program for performing communication synchronization control at the start of communication, measuring a communication establishment time from communication start to communication establishment, and communication from start to communication. A calculation procedure for calculating a communication mask time representing a non-communication time until the start based on the communication establishment time, a storage procedure for storing the communication mask time calculated by the calculation procedure, and the storage procedure for the communication mask time. The communication mask time is read from the storage procedure at the time of startup after storing the information, and the computer is caused to execute a communication procedure for starting communication when the communication mask time elapses.

  According to the communication synchronization device of the first aspect, the measurement means for measuring the communication establishment time from the communication start to the communication establishment, and the communication mask time representing the non-communication time from the start to the communication start based on the communication establishment time. A calculating means for calculating, a storing means for storing the communication mask time calculated by the calculating means, and at the time of activation after the storing means stores the communication mask time, the communication mask time is read from the storing means and the communication mask time has elapsed. Since the communication means for starting communication is configured, it is possible to efficiently prevent occurrence of useless communication processing at the time of activation by starting communication processing using the communication mask time after learning. Even when a new device is added on the network, there is an effect that maintenance work for the communication mask time is not required.

  Further, according to the communication synchronization device according to claim 2, the calculation means is configured to calculate a new communication mask time by adding the communication establishment time to the communication mask time read from the storage means. By extending the communication mask time to reflect the actual communication establishment time, there is an effect that it is possible to efficiently prevent generation of useless communication processing at the time of activation.

  According to the communication synchronization device of the third aspect, the calculating means adds a communication establishment time and a predetermined length of time to the communication mask time read from the storage means, thereby obtaining a new communication mask time. Since the calculation is configured, it is possible to efficiently prevent the occurrence of useless communication processing at the time of activation by correcting the variation in the communication establishment time.

  According to the communication synchronization device of the fourth aspect, when the communication establishment time is 0, the calculation means obtains a new time by subtracting a predetermined length of time from the communication mask time read from the storage device. Since the communication mask time is calculated, the communication mask time is shortened when the communication establishment time is 0, thereby effectively preventing the occurrence of unnecessary communication processing at the time of activation. Play.

  According to the communication synchronization device of the fifth aspect, the storage means stores a counter indicating that the activation with the communication establishment time of 0 is continuously performed, and the calculation means includes the counter a predetermined number of times. Only when the time exceeds the threshold, the communication mask time read out from the storage device is subtracted from the predetermined length of time to calculate a new communication mask time. By preventing this, it is possible to effectively prevent the occurrence of useless communication processing at the time of activation.

  According to the communication synchronization device of the sixth aspect, the storage means stores the minimum mask time representing the minimum value of the communication mask time and the maximum mask time representing the maximum value of the communication mask time, and the calculating means includes The communication mask time is set as the minimum mask time when the calculated communication mask time is smaller than the minimum mask time, and the communication mask time is set as the maximum mask time when the calculated communication mask time is larger than the maximum mask time. Thus, the communication mask time that has become an abnormal value is prevented from being stored in the storage device, and the occurrence of useless communication processing at the time of activation can be effectively prevented.

  According to the communication synchronization device of claim 7, the storage means stores the minimum mask time representing the minimum value of the communication mask time and the maximum mask time representing the maximum value of the communication mask time, and the communication means comprises: When the read communication mask time is smaller than the minimum mask time, the communication mask time is set as the minimum mask time, and when the read communication mask time is larger than the maximum mask time, the communication mask time is set as the maximum mask time. Even if the communication mask time stored on the apparatus takes an abnormal value, it is possible to efficiently prevent generation of useless communication processing at the time of startup by reliably correcting the mask value.

  According to the communication synchronization device of the eighth aspect, the communication means starts the communication monitoring process when the communication mask time read from the storage means has elapsed and the communication establishment time measured by the measurement means has elapsed. Thus, there is an effect that it is possible to prevent a communication error from being detected after communication processing is started until communication is established.

  According to the communication synchronization system of the ninth aspect, the communication establishment time is a measurement means for measuring the communication establishment time from the communication start to the communication establishment, and the communication mask time representing the no communication time from the start to the communication start. A calculation means for calculating the communication mask time, a storage means for storing the communication mask time calculated by the calculation means, and at the start-up after the storage means stores the communication mask time, the communication mask time is read from the storage means to Since the communication means for starting communication at the time of elapse is provided, it is possible to efficiently prevent occurrence of useless communication processing at startup by starting communication processing using the communication mask time after learning. In addition, even when a new device is added on the network, there is an effect that the maintenance work for the communication mask time is not required.

  According to the communication synchronization system of the tenth aspect, when the electronic control unit including the communication synchronization device not provided with the storage means is connected to the network, the communication synchronization device holds the communication mask held by the storage means. Since it is configured to notify the communication synchronization apparatus that does not include the storage means, the communication synchronization apparatus that does not include the storage means uses the communication mask time after learning, thereby efficiently generating unnecessary communication processing at the time of startup. There is an effect that it can be prevented.

  According to the communication synchronization method of the eleventh aspect, the measurement means for measuring the communication establishment time from the communication start to the communication establishment, and the communication mask time representing the non-communication time from the start to the communication start as the communication establishment time. A calculation means for calculating the communication mask time, a storage means for storing the communication mask time calculated by the calculation means, and at the start-up after the storage means stores the communication mask time, the communication mask time is read from the storage means to Since the communication means for starting communication at the time of elapse is provided, it is possible to efficiently prevent occurrence of useless communication processing at startup by starting communication processing using the communication mask time after learning. In addition, even when a new device is added on the network, there is an effect that the maintenance work for the communication mask time is not required.

  According to the communication synchronization program of the twelfth aspect, the measurement means for measuring the communication establishment time from the communication start to the communication establishment, and the communication mask time representing the non-communication time from the start to the communication start as the communication establishment time. A calculation means for calculating the communication mask time, a storage means for storing the communication mask time calculated by the calculation means, and at the start-up after the storage means stores the communication mask time, the communication mask time is read from the storage means to Since the communication means for starting communication at the time of elapse is provided, it is possible to efficiently prevent occurrence of useless communication processing at startup by starting communication processing using the communication mask time after learning. In addition, even when a new device is added on the network, there is an effect that the maintenance work for the communication mask time is not required.

  Exemplary embodiments of a communication synchronization device, a communication synchronization system, a communication synchronization method, and a communication synchronization program according to the present invention will be described below in detail with reference to the accompanying drawings. In the following, first, after explaining the outline of the communication mask time learning process, which is a characteristic part of the present invention common to each embodiment, when the communication mask time is extended (Example 1), the communication mask is extended and shortened. Each of the cases (Example 2) will be described.

(Overview and features)
First, an outline of a communication mask time learning process, which is a characteristic part of the present invention common to the embodiments, will be described. FIG. 1 is an explanatory diagram for explaining an outline of a communication mask time learning process which is a characteristic part of the present invention.

  2. Description of the Related Art In recent years, with increasing performance of vehicles, vehicles are equipped with a large number of sensors and actuators, and the number of ECUs that control these devices is increasing. A plurality of ECUs mounted on the vehicle are connected to each other by an in-vehicle LAN to transmit and receive data and control the entire vehicle. As shown in the figure, each ECU (ECU1 and ECU2) is activated when the driver activates the vehicle system, for example, by operating the ignition switch to "ON".

  However, since the performance of each ECU is usually different, the time from the start of the vehicle system to the start of each ECU varies. For example, in the case shown in the upper side of the figure, each ECU is activated in the order of ECU1, ECU2. Each activated ECU starts “communication processing”. Here, “communication processing” includes processing during a period in which bidirectional communication has not yet been established, and processing after establishment of bidirectional communication.

  For example, even if the ECU 1 starts the communication process and establishes two-way communication with the ECU 2, since the response from the ECU 2 cannot be obtained until the ECU 2 starts the communication process, the ECU 1 obtains the response of the ECU 2. Message transmission will be repeated periodically.

  In order to suppress the occurrence of this wasteful communication process, it is conceivable to set a communication mask time (Tmask) suitable for the performance of each ECU in advance and match the timing at which each ECU starts the communication process. In this case, in consideration of communication with ECUs having various performances, the communication mask time (Tmask) is usually set to a sufficiently long time. However, if the communication mask time (Tmask) is too long, the time until communication is established as a whole is delayed. Further, in this method of setting a static communication mask time in advance, it is necessary to maintain the communication mask time set in another ECU when a new ECU is added to the in-vehicle LAN.

  Therefore, as shown on the lower side of the figure, in the present invention, the communication mask time is dynamically changed by learning the time from when each ECU starts communication processing until communication is established. It was decided to provide a mechanism. In this way, it is possible to autonomously adjust the communication mask time to an appropriate length, and even when a new ECU is added to the in-vehicle LAN, each ECU is dynamically Since the own communication mask time can be changed, it is possible to suppress useless communication processing at the start-up without requiring maintenance work.

  Next, the hardware configuration of the ECU 1 common to the embodiments will be described. FIG. 2 is a block diagram illustrating a hardware configuration and a network configuration of the ECU 1 according to the embodiment of the present invention. As shown in FIG. 1, the ECU 1 includes a CPU (Central Processing Unit) 10, a timer 11, a communication controller 12, a ROM (Read Only Memory) 13, a normal RAM (Random Access Memory) 14, and a standby RAM 15. And each ECU1 is mutually connected by in-vehicle LAN. In the figure, only three ECUs 1 are shown, but the number of ECUs 1 is not limited.

  The CPU 10 performs overall control of the ECU 1 and controls other devices in the ECU 1 connected via a bus. The timer 11 is a timer such as a free-run timer for detecting communication timing, and the communication controller 12 is a device that controls communication between the in-vehicle LAN and the ECU 1.

  The ROM 13 is a read-only memory used as a memory for storing programs and static data. The normal RAM 14 is a writable and readable memory used as an arithmetic memory and is initialized when the system is activated. The standby RAM 15 is a RAM that is connected to a standby power supply that continues to be supplied even when the system is terminated, and that can retain stored data even after the system is terminated.

  The standby RAM 15 is used to hold data such as a communication mask time (Tmask) after learning. In the embodiment according to the present invention, each ECU 1 has the standby RAM 15. However, at least one ECU 1 connected to the in-vehicle LAN has the standby RAM 15, and the communication mask time ( Tmask) may be notified to other ECUs 1.

  Next, the communication mask time learning process will be described in more detail with reference to FIGS. In the first embodiment, a case where the communication mask time is learned and the communication mask time is extended will be described.

  FIG. 3 is a block diagram illustrating a software configuration of the ECU 1 according to the first embodiment of the present invention. Note that the programs of the communication start synchronization unit 100 and the communication processing unit 110 are stored in the ROM 13 and are expanded on the normal RAM 14 at the time of execution. Each data in the storage unit 120 is held in the ROM 13, the normal RAM 14, or the standby RAM 15. Note that data used at the next start-up is held in the standby RAM 15 that can hold the stored data even after the power is turned off.

  As shown in the figure, the ECU 1 includes a communication start synchronization unit 100, a communication processing unit 110, and a storage unit 120. The communication start synchronization unit 100 further includes a communication mask value update processing unit 101 and a communication establishment time measurement unit 102, and the storage unit 120 further includes a communication mask time (Tmask) 121.

  If the communication processing unit 110 starts communication processing when the ECU 1 is activated, the communication start synchronization unit 100 measures the communication establishment time (Tok) that is the time from the start of communication to the establishment of communication, and this is taken. It is a processing unit that calculates a communication mask time (Tmask) 121 based on the communication establishment time (Tok) and stores it in the storage unit 120.

  The communication mask value update processing unit 101 acquires the communication establishment time (Tok) measured by the communication establishment time measurement unit 102, and calculates the communication mask time (Tmask) 121 based on the acquired communication establishment time (Tok). . For example, if the value of the communication mask time (Tmask) 121 before learning is 20 msec and the value of the measured communication establishment time (Tok) is 2 msec, 22 msec obtained by adding both values to the new communication is added. The value is calculated as the value of the mask time (Tmask) 121. Then, the calculated communication mask (Tmask) 122 is stored in the storage unit 120.

  The communication establishment time measuring unit 102 measures a communication establishment time (Tok), which is a time from the start of communication to the establishment of communication, using the timer 11, and passes the measurement result to the communication mask value update processing unit 101. Do it. For example, if the communication processing unit 110 sends a first response request to the in-vehicle LAN, the communication establishment time measuring unit 102 starts measuring the timer.

  If the communication processing unit 110 receives a response from another ECU 1 without transmitting a second response request and communication is established, the communication establishment time (Tok) value is set to 0 msec. In addition, if the communication processing unit 110 transmits the second and subsequent response requests at 1 msec intervals and communication is established after the fifth response request is transmitted, the communication establishment time (Tok) value is set to 4 msec. Note that the transmission interval of the response request can be set to an arbitrary value.

  The communication processing unit 110 is a processing unit that performs data transmission / reception with another ECU 1 via the in-vehicle LAN. The communication processing unit 110 reads the communication mask time (Tmask) 121 from the storage unit 120, waits for the read communication mask time (Tmask) 121, and then starts communication processing. For example, if the communication mask time is 5 msec, communication processing is not performed for a period of 5 msec after the operation is started, and a response request is periodically sent to the in-vehicle LAN when the period elapses. Then, after a response is received from another ECU 1 and bidirectional communication is established, bidirectional data transmission / reception is performed with the other ECU 1.

  The storage unit 120 is configured on the ROM 13, the normal RAM 14, or the standby RAM 15. For example, data that is retained even after the power is turned off and is used at the next startup is retained on the standby RAM 15. Static data is stored in the ROM 13 and data that is dynamic data but is not used after the power is turned off is stored in the normal RAM 14.

  The communication mask time (Tmask) 121 is time data calculated by the communication mask value update processing 101 and is used by the communication processing unit 110. Since this communication mask time (Tmask) 121 is used at the next startup, the storage destination is the standby RAM 15.

  Next, a communication mask time learning process when it is necessary to extend the communication mask time (Tmask) 121 will be described with reference to FIGS. FIG. 4A is an explanatory diagram for explaining the communication mask time (Tmask) 121 and the communication establishment time (Tok) when it is necessary to extend the communication mask time (Tmask) 121. FIG. It is explanatory drawing for demonstrating the communication mask time (Tmask) 121 after learning.

  FIG. 4A illustrates the communication establishment time (Tok) and the communication mask time (Tmask) 121 of the ECU 1 when the ECU 1 starts communication processing before the ECU 2. The ECU 2 is an ECU having the same configuration as the ECU 1.

  As shown in the figure, when the ECU 1 is activated, the communication processing unit 110 of the ECU 1 reads out the communication mask time (Tmask) 121 from the storage unit 120 and waits for the read communication mask time (Tmask) 121 for the communication processing. To start. Then, the communication establishment time measuring unit 102 of the ECU 1 measures a communication establishment time (Tok) that is a time from when communication processing is started until communication is established. Subsequently, the communication mask value update processing unit 101 calculates a communication mask time (Tmask) 121 after learning based on the communication establishment time (Tok), and writes it in the communication mask time (Tmask) 121 of the storage unit 120. .

  For example, if the value of Tmask in the figure is 10 msec and the value of Tok is 3 msec, the value of the communication mask time (Tmask) 121 after learning is 13 msec. The communication mask time (Tmask) 121 after learning is used by the ECU 1 at the next start-up of the vehicle system.

  As shown in FIG. 4B, when the vehicle system is activated again and the ECU 1 is activated, the communication processing unit 110 of the ECU 1 reads the communication mask time (Tmask) 121 from the storage unit 120, and the read communication mask time (Tmask). After waiting for the period 121, the communication process is started. Unlike the case of FIG. 4-1 before learning, in the case of FIG. 4-2 after learning, the communication processing start time between the ECU 1 and the ECU 2 approaches, so that the ECU 1 and the ECU 2 are not subjected to unnecessary communication processing. Communication can be established.

  Next, a processing procedure of the ECU 1 according to the first embodiment will be described. FIG. 5 is a flowchart illustrating a processing procedure of the ECU 1 according to the first embodiment.

  First, the communication processing unit 110 of the ECU 1 reads the communication mask time (Tmask) 121 from the storage unit 120 (step S101). Then, the value of the read communication mask time (Tmask) 121 is set in the timer 11 (step S102), and the elapse of Tmask is awaited (No in step S103).

  If Tmask has elapsed (Yes at Step S103), the communication establishment time measuring unit 102 performs a communication establishment time (Tok) measurement process (Step S104). Here, the processing content of this step S104 is demonstrated using FIG. FIG. 6 is a flowchart showing a procedure of the Tok measurement process shown in FIG.

  As shown in FIG. 6, first, the communication establishment time (Tok) is set to 0 (step S201), and the communication establishment process is started (step S202). Specifically, in step S202, the communication processing unit 110 sets a timer (timer with a length of Twait) for periodically transmitting a response request, and transmits the first response request.

  If a response is received from another ECU 1, it is determined that communication is established (Yes at step S203), and the process returns. In this case, the value of Tok remains 0. On the other hand, if no response is received and the timer (timer of Twait length) times out (No at Step S203), Tok + Twait is set to Tok (Step S204). Subsequently, a timer (a timer having a length of Twait) is set, a response request is transmitted, and a Twait period is awaited (step S205).

  And it returns to the process of step S203 again and repeats the process of step S204-step S205 until communication is materialized. In this way, in the Tok measurement process, the time from the start of the communication process to the communication establishment is measured, and the measured communication establishment time (Tok) is passed to the communication mask value update processing unit 101.

  Returning to FIG. 5, the Tmask update process (step S105) will be described. Here, the processing content of this step S105 is demonstrated using FIG. FIG. 7 is a flowchart showing a processing procedure of the Tmask update process shown in FIG.

  As shown in FIG. 7, in this Tmask update process, the communication mask time (Tmask) 121 is updated using the Tok passed from the communication establishment time measuring unit 102. Specifically, Tmask + Tok is set in Tmask (step S301).

  Returning to FIG. 5, step S106 will be described. When the Tok measurement process is performed (step S104) and the Tmask update process is performed based on the measured Tok (step S105), the ECU 1 starts a normal communication process (step S106). Here, normal communication processing refers to communication processing after bidirectional communication is established.

  As described above, in the first embodiment, the communication mask time (Tmask) is recalculated by reflecting the communication establishment time (Tok), which is the measurement time from the start of communication to the communication establishment, by the communication mask time learning process. Therefore, at the next start-up, the communication process is started using the learned Tmask, thereby correcting the variation in the communication start time between the ECUs and generating unnecessary communication processes at the time of startup. Can be suppressed. In addition, since each ECU 1 autonomously sets the communication mask time (Tmask) by the learning process, even if a new ECU is connected to the in-vehicle LAN, an appropriate mask is performed without performing maintenance work. The time can be set automatically.

  In the first embodiment, in order to explain the mechanism of the learning process that dynamically changes the communication mask time, which is a characteristic part of the present invention, the communication mask time extension process, which is the most basic case, has been described. . However, the present invention is not limited to this, and can be applied to processing for shortening communication mask time and processing corresponding to measurement errors and variations in the operation of each ECU 1. Hereinafter, these processes will be described in detail.

  In the second embodiment, a case where the communication mask time is learned and the communication mask is extended and shortened will be described. Note that the description of the same parts as those in the first embodiment is omitted or only a brief description.

  FIG. 8 is a block diagram illustrating a software configuration of the ECU 1 according to the second embodiment of the present invention. Note that the programs of the communication start synchronization unit 100 and the communication processing unit 110 are stored in the ROM 13 and are expanded on the normal RAM 14 at the time of execution. Each data in the storage unit 120 is held in the normal RAM 14 or the standby RAM 15. Note that the data that is retained even after the power is turned off and is used at the next startup is retained in the standby RAM 15.

  As shown in the figure, the ECU 1 includes a communication start synchronization unit 100, a communication processing unit 110, and a storage unit 120. The communication start synchronization unit 100 further includes a communication mask value update processing unit 101 and a communication establishment time measurement unit 102, and the storage unit 120 includes a communication mask time (Tmask) 121, a margin time (α) 122, and a reduction time. (Β) 123, a maximum mask time (Tmaskmax) 124, and a minimum mask time (Tmaskmin) 125 are further included.

  If the communication processing unit 110 starts communication processing when the ECU 1 is activated, the communication start synchronization unit 100 measures the communication establishment time (Tok) that is the time from the start of communication to the establishment of communication, and this is taken. It is a processing unit that calculates a communication mask time (Tmask) 121 based on the communication establishment time (Tok) and stores it in the storage unit 120.

  The communication mask value update processing unit 101 acquires the communication establishment time (Tok) measured by the communication establishment time measurement unit 102 and calculates a communication mask time (Tmask) 121 based on the acquired communication establishment time (Tok). The point which is a process part is the same as that of Example 1. FIG.

  In the second embodiment, margin time (α) 122 for dealing with measurement errors and variations in operation of each ECU 1, shortened time (β) 123 for dealing with shortening of communication mask time (Tmask) 121, communication mask A more appropriate communication mask time (Tmask) 121 is calculated by using the maximum mask time (Tmaskmax) 124 and the minimum mask time (Tmaskmin) 125 for preventing the time (Tmask) 121 from becoming an abnormal value. It was. Since these data (122 to 125) are static data, the storage destination is the ROM 13 or the standby RAM 15.

  The margin time (α) 122 is static data used to cope with measurement errors and variations in the operation of the ECUs 1 and is used by the communication mask value update processing unit 101. In the first embodiment, the communication establishment time (Tok) representing the time from the start of communication to the establishment of communication is measured. However, the measurement value may include an error, and may be a communication partner. There may be a variation in the operation of the ECU 1. Therefore, a margin time (α) 122 for correcting the measured Tok and the actual value is introduced, and a value obtained by adding the margin time (α) 122 to the measured Tok is used.

  The shortening time (β) 123 is a step time used to shorten the Tmask when the communication mask time (Tmask) 121 becomes too large, and takes a value of 0.5 msec, for example. Here, the case where the communication mask time (Tmask) 121 becomes too large means that the ECU 1 having a low startup speed is replaced with the ECU 1 having a high startup speed due to a system change or the like, or a measurement error or a temporary failure. The communication mask time may take a long value.

  The maximum mask time (Tmaskmax) 124 and the minimum mask time (Tmaskmin) 125 are used to prevent the communication mask time (Tmask) 121 from becoming an abnormal value due to a measurement error or a temporary failure. That is, the communication mask time (Tmask) 121 is adjusted to be not less than the minimum mask time (Tmaskmin) 125 and not more than the maximum mask time (Tmaskmax) 124.

  Next, a communication mask time learning process when the communication mask time (Tmask) 121 needs to be shortened will be described with reference to FIGS. 9-1 and 9-2. FIG. 9A is an explanatory diagram for explaining the communication mask time (Tmask) 121 when the communication mask time (Tmask) 121 needs to be shortened, and FIG. 9-2 shows the communication mask time after learning. It is explanatory drawing for demonstrating (Tmask) 121.

  FIG. 9A illustrates the communication mask time (Tmask) 121 of the ECU 1 when the ECU 1 starts communication processing later than the ECU 2. The ECU 2 is an ECU having the same configuration as the ECU 1.

  As shown in the figure, when the ECU 1 is activated, the communication processing unit 110 of the ECU 1 reads out the communication mask time (Tmask) 121 from the storage unit 120 and waits for the read communication mask time (Tmask) 121 for the communication processing. To start. And since ECU2 used as a communication other party has already started the communication process, communication is immediately established. However, the ECU 2 performs useless communication processing during the period until communication with the ECU 1 is established. Therefore, in such a case, it is necessary to shorten the communication mask time (Tmask) 121 to accelerate the start of the communication process of the ECU and to approach the start time of the communication process of the ECU 2. Specifically, the Tmask is shortened by subtracting the shortened time (β) 123 from the communication mask time (Tmask) 121 to obtain a new communication mask time (Tmask) 121.

  As shown in FIG. 9-2, when the vehicle system is activated again and the ECU 1 is activated, the communication processing unit 110 of the ECU 1 reads out the communication mask time (Tmask) 121 from the storage unit 120, and the read communication mask time (Tmask). After waiting for the period 121, the communication process is started. This Tmask value is obtained by subtracting the shortening time (β) 123 from the Tmask value at the previous activation. Therefore, the communication processing start time between the ECU 1 and the ECU 2 is closer in the case of FIG. 9-2 after learning than in the case of FIG. 9-1 before learning, and wasteful communication processing is reduced. By repeating the activation of the vehicle system, the communication processing start times of the ECU 1 and the ECU 2 coincide with each other.

  Next, a processing procedure of the ECU 1 according to the second embodiment will be described. The only difference from FIG. 5 that describes the processing procedure according to the first embodiment is only the Tmask update process (step S105), and therefore, variations of this Tmask update process will be described with reference to FIGS. And

  FIG. 10 is a flowchart showing a processing procedure in which the Tmask update process shown in FIG. 5 is changed to correspond to the shortening of the communication mask time. First, the communication mask value update processing unit 101 determines whether or not the communication establishment time (Tok) is 0 (step S401). If the communication establishment time (Tok) is not 0 (No at Step S401), Tmask is too short, and Tmask + Tok + α is set as a new Tmask value (Step S402). On the other hand, when the communication establishment time (Tok) is 0 (Yes at Step S401), Tmask-β is set as a new value of Tmask (Step S403).

  As described above, since the Tmask is extended or shortened depending on whether or not the communication establishment time (Tok) is 0, an appropriate Tmask is calculated not only when the Tmask is too short but also when it is too long. can do. Further, since the value obtained by adding the margin time (α) 122 to the communication establishment time (Tok) is used, it is possible to correct the deviation of the communication establishment time (Tok) due to the measurement error and the variation in the operation of the other ECU 1. .

  Next, a modification of the Tmask update process shown in FIG. 10 will be described with reference to FIG. FIG. 11 is a flowchart of a process procedure of the first modification of the Tmask update process depicted in FIG. In FIG. 10, when Tmask is too long, the shortening time (β) 123 is subtracted from Tmask to obtain a new Tmask value. However, frequent learning for shortening Tmask tends to reflect the influence of measurement errors and the like, and thus tends to increase the frequency of setting Tmask to a value that is too short, which may increase unnecessary communication processing. Therefore, in the Tmask update process shown in FIG. 11, a process for suppressing the execution frequency of learning for shortening Tmask is added.

  As shown in FIG. 11, the communication mask value update processing unit 101 first determines whether or not the communication establishment time (Tok) is 0 (step S501). If the communication establishment time (Tok) is not 0 (No at Step S501), Tmask is too short, so Tmask + Tok + α is set as a new Tmask value (Step S505). Then, 0 is set to cnt representing the number of executions of learning for shortening Tmask (step S506), and the process returns.

  Here, cnt is a counter for counting the process of shortening Tmask (step S504), and is used at the next start-up, so the holding destination is the standby RAM 15. N used in step 505 is numerical data for executing a process (step S504) for shortening Tmask at a rate of once every N times. Since this data is static data, the storage destination is the ROM 13 or the standby RAM 15.

  When the communication establishment time (Tok) is 0 (Yes at Step S501), the value of cnt is increased by 1 (Step S502). Subsequently, it is determined whether or not this cnt is larger than N (step S503). If cnt is equal to or smaller than N (No in step S503), the process returns.

  On the other hand, if such cnt is larger than N (Yes at step S503), Tmask-β is set as a new value of Tmask (step S504). Then, the value of cnt is set to 0 (step S506) and the process returns.

  As described above, the process of shortening Tmask (step S504) is executed at a rate of once every N times using cnt that represents the number of times of learning for shortening Tmask. Therefore, learning for shortening Tmask is performed. An increase in unnecessary communication processing due to frequent implementation can be suppressed.

  Next, a second modification of the Tmask update process shown in FIG. 10 will be described with reference to FIG. FIG. 12 is a flowchart of a process procedure of the second modification of the Tmask update process depicted in FIG. In FIG. 10, the process of extending Tmask (step S402) and the process of shortening Tmask (step S403) are performed, but the Tmask value may become an abnormal value due to the occurrence of a measurement error or a temporary failure. is there. In such a case, unnecessary communication processing occurs on the contrary, and it is necessary to limit the values that Tmask can take. Therefore, in the Tmask update process shown in FIG. 12, a process for restricting the values that Tmask can take is added.

  As shown in FIG. 12, first, the communication mask value update processing unit 101 determines whether or not the communication establishment time (Tok) is 0 (step S601). If the communication establishment time (Tok) is not 0 (No at Step S601), Tmask is too short, and Tmask + Tok + α is set as a new Tmask value (Step S602). On the other hand, when the communication establishment time (Tok) is 0 (Yes at Step S601), Tmask-β is set as a new value of Tmask (Step S603).

  When the Tmask extension process (step S602) or the Tmask reduction process (step S603) is completed, it is determined whether or not the updated Tmask value is smaller than the minimum mask time (Tmaskmin) 125 (step S604). . If the value of Tmask is smaller than the minimum mask time (Tmaskmin) 125 (Yes in step S604), Tmaskmin is set as a new value of Tmask (step S605). On the other hand, when the value of Tmask is equal to or greater than the minimum mask time (Tmaskmin) 125, the process of step S605 is not performed.

  Subsequently, it is determined whether or not the value of Tmask is larger than the maximum mask time (Tmaskmax) 124 (step S606). If the value of Tmask is greater than the maximum mask time (Tmaskmax) 124 (Yes at step S606), Tmaskmax is set as a new value of Tmask (step S607), and the process returns. On the other hand, if the value of Tmask is equal to or greater than the maximum mask time (Tmaskmax) 124, the process returns without performing the process of step S607.

  As described above, since the communication mask time (Tmask) 121 is processed to be not less than the minimum mask time (Tmaskmin) 125 and not more than the maximum mask time (Tmaskmax) 124, the communication mask time (Tmask) 121 takes an abnormal value. As a result, unnecessary communication processing can be prevented from occurring.

  In FIG. 12, the configuration not including the “processing for suppressing the execution frequency of learning for shortening Tmask” described in FIG. 11 has been described for easy understanding. However, it is also possible to adopt a configuration including a process for suppressing the execution frequency of learning for shortening Tmask. In addition, when including the process which suppresses the execution frequency of the learning which shortens Tmask, the process of step S601-S603 of FIG. 12 is replaced with the process of step S501-step S506 of FIG.

  Next, the start time of the communication monitoring process according to the embodiment of the present invention will be described with reference to FIG. FIG. 13 is an explanatory diagram for explaining the start time of the communication monitoring process according to the embodiment of the present invention. The communication processing unit 110 of the ECU 1 normally performs a communication monitoring process for detecting a communication error. However, if a communication error is detected between the start of the communication process and the establishment of communication, there is a disadvantage that the error process is performed despite the normal process.

  Therefore, as shown in FIG. 13, the communication monitoring process is not performed until the communication is established after the process for establishing the communication is started, and the communication monitoring process is performed after the communication is established. By doing in this way, the communication error after communication is established can be detected efficiently without detecting a communication error during the process for establishing communication. This communication monitoring process is performed after the normal communication process start (step S106) shown in FIG.

  As described above, in the second embodiment, in addition to the communication establishment time (Tok), the margin time (α) and the communication mask time (Tmask) are shortened to cope with the measurement error and the variation in the operation of each ECU 1. By using the shortened time (β) for dealing with the above, the maximum mask time (Tmaskmax) and the minimum mask time (Tmaskmin) for preventing the communication mask time (Tmask) from becoming an abnormal value, Since Tmask) is calculated, use of a more appropriate communication mask time (Tmask) can effectively suppress occurrence of useless communication processing at the time of activation.

  In the embodiment described above, the case where the software shown in FIG. 3 is configured on the hardware of the ECU 1 shown in FIG. 2 has been described. However, an independent communication synchronization device is configured in the ECU 1, and The software shown in FIG. 3 may be executed.

  As described above, the communication synchronization device, the communication synchronization system, the communication synchronization method, and the communication synchronization program according to the present invention are useful for the communication start synchronization processing of the communication device on the network. Suitable for start synchronous processing.

It is explanatory drawing for demonstrating the outline | summary of the learning process of the communication mask time which is the characteristic part of this invention. It is a block diagram which shows the hardware constitutions and network structure of ECU which concern on the Example of this invention. It is a block diagram which shows the software structure of ECU1 which concerns on Example 1 of this invention. It is explanatory drawing for demonstrating the communication mask time and communication establishment time when it is necessary to extend communication mask time. It is explanatory drawing for demonstrating the communication mask time after learning. 3 is a flowchart illustrating a processing procedure of a communication start synchronization unit according to the first embodiment. It is a flowchart which shows the process sequence of Tok measurement process shown in FIG. It is a flowchart which shows the process sequence of the Tmask update process shown in FIG. It is a block diagram which shows the software structure of the communication start synchronizer concerning Example 2 of this invention. It is explanatory drawing for demonstrating communication mask time when it is necessary to shorten communication mask time. It is explanatory drawing for demonstrating the communication mask time after learning. It is a flowchart which shows the process sequence which changed the Tmask update process shown in FIG. 5 so that it might respond | correspond to shortening of communication mask time. It is a flowchart which shows the process sequence of the modification 1 of the Tmask update process shown in FIG. It is a flowchart which shows the process sequence of the modification 2 of the Tmask update process shown in FIG. It is explanatory drawing for demonstrating the start time of the communication monitoring process which concerns on the Example of this invention.

Explanation of symbols

1 Electronic control unit (ECU)
2 Electronic control unit (ECU)
10 Central processing unit (CPU)
11 Timer 12 Communication controller 13 ROM
14 Normal RAM
15 Standby RAM
DESCRIPTION OF SYMBOLS 100 Communication start synchronous part 101 Communication mask value update process part 102 Communication establishment time measurement part 110 Communication process part 120 Storage part 121 Communication mask time (Tmask)
122 Margin time (α)
123 Reduction time (β)
124 Maximum mask time (Tmaskmax)
125 Minimum mask time (Tmaskmin)

Claims (12)

A communication synchronization device that performs communication synchronization control at the start of communication,
Measuring means for measuring the communication establishment time from the communication start to communication establishment;
A calculation means for calculating a communication mask time representing a non-communication time from start to communication start based on the communication establishment time;
Storage means for storing the communication mask time calculated by the calculation means;
And a communication unit configured to read out the communication mask time from the storage unit and start communication when the communication mask time elapses when the storage unit is activated after storing the communication mask time. Synchronizer.   The communication synchronization apparatus according to claim 1, wherein the calculation unit calculates a new communication mask time by adding the communication establishment time to the communication mask time read from the storage unit.   2. The calculation unit according to claim 1, wherein the communication unit calculates a new communication mask time by adding the communication establishment time and a predetermined length of time to the communication mask time read from the storage unit. Or the communication synchronizer of 2.   The calculation means calculates a new communication mask time by subtracting a predetermined length of time from the communication mask time read from the storage device when the communication establishment time is zero. The communication synchronization device according to claim 1, 2, or 3.   The storage means stores a counter indicating that the activation with the communication establishment time of 0 has been continuously performed, and the calculation means only stores the storage device when the counter exceeds a predetermined number of times. The communication synchronization apparatus according to claim 4, wherein a new communication mask time is calculated by subtracting a predetermined length of time from the communication mask time read out from the communication mask.   The storage means stores a minimum mask time representing the minimum value of the communication mask time and a maximum mask time representing the maximum value of the communication mask time, and the calculating means stores the calculated communication mask time in the minimum The communication mask time is set as the minimum mask time when smaller than a mask time, and the communication mask time is set as the maximum mask time when the calculated communication mask time is larger than the maximum mask time. The communication synchronization device according to any one of 1 to 5.   The storage means stores a minimum mask time representing a minimum value of the communication mask time and a maximum mask time representing a maximum value of the communication mask time, and the communication means stores the read communication mask time in the minimum mask time. 2. The communication mask time is set as the minimum mask time when the time is smaller than the time, and the communication mask time is set as the maximum mask time when the read communication mask time is longer than the maximum mask time. The communication synchronizer as described in any one of -5.   The communication means starts the communication monitoring process when the communication mask time read from the storage means elapses and when the communication establishment time measured by the measurement means elapses. The communication synchronization device according to any one of 7. A communication synchronization system comprising an electronic control unit including a communication synchronization device that is mounted on a mobile body and performs communication synchronization control at the start of communication, and a network that interconnects the plurality of electronic control units,
Each of the communication synchronization devices is
Measuring means for measuring the communication establishment time from the communication start to communication establishment;
A calculation means for calculating a communication mask time representing a non-communication time from start to communication start based on the communication establishment time;
Storage means for storing the communication mask time calculated by the calculation means;
And a communication unit configured to read out the communication mask time from the storage unit and start communication when the communication mask time elapses when the storage unit is activated after storing the communication mask time. Synchronous system.   When an electronic control unit including a communication synchronization device that does not include the storage unit is connected to the network, the communication synchronization unit performs communication that does not include the storage unit with the communication mask time held by the storage unit. The communication synchronization system according to claim 9, wherein a notification is sent to the synchronization device. A communication synchronization method for performing communication synchronization control at the start of communication,
A measurement process for measuring communication establishment time from communication start to communication establishment;
A calculation step of calculating a communication mask time representing a non-communication time from start to communication start based on the communication establishment time;
A storage step of storing the communication mask time calculated by the calculation step;
A communication step of reading out the communication mask time from the storage step and starting communication when the communication mask time elapses when the storage step is started after storing the communication mask time. Synchronization method. A communication synchronization program that performs communication synchronization control at the start of communication,
A measurement procedure for measuring the communication establishment time from communication start to communication establishment;
A calculation procedure for calculating a communication mask time representing a non-communication time from activation to communication start based on the communication establishment time;
A storage procedure for storing the communication mask time calculated by the calculation procedure;
A communication procedure for reading out the communication mask time from the storage procedure and starting communication when the communication mask time elapses when the storage procedure is started after storing the communication mask time. Communication synchronization program.

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