JP6449665B2 - In-vehicle communication device - Google Patents

Description

  The present invention relates to a function of an in-vehicle communication device for selecting a communication method in a communication system formed in a vehicle.

Recent automobiles are equipped with a large number of information collection devices (hereinafter referred to as “node units”) such as sensors and cameras to enhance information collection capabilities, thereby improving safety, comfort and economy. . Along with this, a large number of processors such as ECUs (Electronic Control Units) that manage node units are also mounted on vehicles. The node unit is connected to the ECU via a communication line, and in recent years, the introduction of Ethernet (registered trademark) to the in-vehicle LAN has been studied. Various information such as the control status of engines, doors, mirrors, air conditioners and the distance to obstacles ahead is collected from a large number of node units, and this information is used for vehicle control, and partly by the instrument panel. The driver is also notified.
Hereinafter, communication devices constituting the in-vehicle communication system such as the node unit and the ECU are collectively referred to as “in-vehicle communication device”.

  In order for the in-vehicle communication device A and the in-vehicle communication device B to communicate, it is necessary to match the communication speed with the communication method (full duplex / half duplex). As a function for automatically setting the communication speed and communication method, an Auto-Negotiation function (hereinafter abbreviated as “A / N function”) is defined in IEEE802.3. When both the in-vehicle communication device A and the in-vehicle communication device B have the A / N function turned on, the communication speed and the communication method can be automatically matched to each other (see Patent Document 1). .

JP 2010-252031 A

  The A / N function is convenient, but it takes about several tens of milliseconds to several hundreds of milliseconds for activation, and is not suitable for an in-vehicle communication network that strictly requires real-time performance. There is a method of manually setting a communication method or the like in advance without using the A / N function, but it is complicated to perform such setting in many in-vehicle communication devices.

  Furthermore, when the in-vehicle communication device A has the A / N function turned on and the in-vehicle communication device B has turned off the A / N function, the in-vehicle communication device A does not know the communication method of the in-vehicle communication device B. Set to heavy mode. If the in-vehicle communication device B is set to the full-duplex mode, the communication method becomes inconsistent and the communication efficiency is greatly reduced.

  The present invention has been made in view of such a situation, and its main object is to set the communication method of the in-vehicle communication device in the in-vehicle communication network appropriately and at high speed.

An aspect of the present invention relates to an in-vehicle communication device connected to another in-vehicle communication device in an in-vehicle communication system. This device determines the communication method of its own device to full-duplex setting or half-duplex setting by inquiring the communication method of other in-vehicle communication device, and records the determined communication method in the setting information, A communication execution unit that executes communication with another in-vehicle communication device using the communication method recorded in the setting information.
The communication setting unit performs processing for determining the communication method of the own device by inquiring about the communication method of another in-vehicle communication device, and as a result, the communication method of the own device is a half-duplex setting and determines the communication method. If this is the first time, inquire the communication method to another in-vehicle communication device again, and if the communication method of the own device is a half-duplex setting and the process for determining the communication method is not the first time, After the communication method of the own device is determined and recorded as setting information, the function for inquiring about the communication method of another in-vehicle communication device is set off.

According to this aspect, when the communication method of the own device is the half-duplex setting and the process for determining the communication method is the first time, the communication method inquiry is made again to the other in-vehicle communication device, and the communication of the own device is performed. In cases other than the case where the method is half-duplex setting and the process for determining the communication method is the first time, the function for inquiring about the communication method of other in-vehicle communication devices is set off, so no negotiation is performed thereafter. In addition, the communication method can be determined appropriately and at high speed according to the setting information.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes easy to set the communication system of the vehicle-mounted communication apparatus in a vehicle-mounted communication network appropriately and at high speed.

It is a hardware block diagram of a vehicle-mounted communication system. It is a flowchart which shows the general process process before ECU starts communication. It is a flowchart which shows the process of the communication pre-process in this embodiment. It is a schematic diagram which shows the process of the communication pre-processing accompanying replacement | exchange of a vehicle-mounted communication apparatus.

FIG. 1 is a hardware configuration diagram of the in-vehicle communication system 100.
In FIG. 1, an ECU 102 a (in-vehicle communication device) and an ECU 102 b (in-vehicle communication device) are connected via a communication line 108. The “in-vehicle communication device” may be any device that is mounted in the in-vehicle communication system 100 and has a communication function, such as a sensor, a camera, and a switching hub, in addition to the ECU.

  ECU 102 includes a communication setting unit 104 and a communication execution unit 106. The communication setting unit 104 has an A / N function. The communication setting unit 104 selects a communication speed and a communication method (full duplex / half duplex) by negotiating with the communication partner, and stores these in the nonvolatile memory as setting information. The communication execution unit 106 executes communication processing at the communication speed and communication speed recorded as the setting information.

FIG. 2 is a flowchart showing a general processing process before the ECU 102 starts communication.
Before describing the processing method of the present embodiment, a processing process of a typical pre-communication process (hereinafter referred to as “pre-communication process”) will be described in relation to FIG. 2, and the problems will be clarified. To do. Here, it is assumed that the in-vehicle communication system 100 includes a mixture of the ECU 102 in which the A / N function is set on and the ECU 102 in which the A / N function is set off.

  First, when the ECU 102 is activated and the pre-communication process is started, when the A / N function of the own apparatus is on (Y in S10), the communication setting unit 104 executes the A / N process (S12). Specifically, the ECU 102 transmits a combination of a communication speed and a communication method that can be supported by the own apparatus to a communication partner by an FLP (Fast Link Pulse) signal. When the partner ECU 102 also has the A / N function turned on (Y in S14), the FLP signal is also transmitted from the communication partner. Then, the maximum communication speed that can be handled with each other is set, and the communication method is also set (S16). If both are capable of full-duplex communication, the full-duplex communication method is used, otherwise both are half-duplex communication methods (case 1).

On the other hand, when the A / N function of the partner ECU 102 is off (N in S14), the partner sends an IDLE signal instead of an FLP signal. Although the communication speed of the other party can be determined from the IDLE signal, the compatible communication method is not known. In this case, half-duplex communication is set (S18), and the pre-communication process is completed (case 2).
When the A / N function of the own apparatus is off (N in S10), the communication speed and communication method recorded in the setting information are determined as they are (case 3).

Consider the above three cases.
Case 1:
The two ECUs 102 can match the communication speed and the communication method by the A / N function. However, it takes a processing time of several tens of milliseconds or more to execute the A / N function.
Case 2:
It still takes time to perform the A / N function. In addition, because the other party's communication method is unknown, it is automatically set to half duplex. However, if the other party's communication method is set to full duplex, the communication method mismatch (hereinafter referred to as “method”). Will be called “inconsistency”). System mismatch is undesirable because it reduces communication efficiency.
Case 3:
Since the A / N function is not executed, the speed is high. However, since the other party's communication method is unknown, there is still a risk of inconsistency.

FIG. 3 is a flowchart showing the process of the pre-communication process in the present embodiment.
In the present embodiment, when the ECU 102 is newly installed or replaced, the communication method and the like are appropriately set by the A / N function and recorded as setting information, and this setting information is stored in communication pre-processing executed thereafter. Use it as is. Since it is not necessary to always activate the A / N function at power-on or reset, the communication pre-processing can be executed at high speed. The portion surrounded by the dotted line in FIG. 3 is the same as the conventional method shown in FIG.

When the communication method is determined in cases 1 and 2, the first (first time) A / N process (new in S20) associated with the new installation / replacement (Y in S20), and the own device is set to half duplex If this is the case (Y in S22), there is a possibility that the method mismatch of case 2 has occurred. In case 2, the system mismatch occurs when the communication partner has turned off the A / N function, so the communication setting unit 104 requests the communication partner to turn on the A / N function, The link is reset (S24). After that, the processes after S12 are executed again. Since the communication partner is turned on in the A / N function, the process proceeds in the order of S12, S14 Y, S16 (re-A / N process), and the communication method is appropriately set.
As a result of executing the A / N process, the half-duplex setting may be correctly performed. In this case, the re-A / N process is also executed.

  When the above-described re-A / N processing is executed (N in S20), or when the first A / N function is appropriately executed and the own apparatus is set to full duplex (N in S22) The communication setting unit 104 deterministically records the communication speed and communication method in the setting information (S26), turns off the A / N function (S28), and the pre-communication processing ends.

  In the case where the A / N function of the own device is off, that is, in case 3, if the communication partner does not request the A / N function to be turned on (N in S 30), communication is established according to the setting information (Y in S 34). ), The pre-communication process ends. If communication establishment has failed (N in S34), the process proceeds to S32. The case of communication establishment failure will be described in detail later. On the other hand, when the communication partner requests to turn on the A / N function (Y in S30), the A / N function is turned on (S32), and the process proceeds to S12. At this time, the A / N process is executed again.

  At the time of vehicle assembly, the A / N function of all ECUs 102 (vehicle communication devices) is turned on. Since the in-vehicle communication device mounted on the in-vehicle communication system 100 is often capable of full-duplex operation, normally, when the power is first turned on after the vehicle is assembled, the case 1 to S20 Y, the S22 N, Through S26, the communication method and the like are confirmed and recorded in the setting information, and the A / N function is turned off (initial setting process).

  Once the communication method is recorded in the setting information, in other words, after the initial process is completed, the A / N function is off. Therefore, when executing the pre-communication process by turning on the power or resetting, the processes of S10 and S30 are performed. N, communication is started through Y of S34. Since the A / N process is not executed, the pre-communication process is fast.

FIG. 4 is a schematic diagram showing a processing process of pre-communication processing associated with replacement of the in-vehicle communication device 110.
First, it is assumed that the in-vehicle communication device 110 </ b> A and the in-vehicle communication device 110 </ b> B are connected via the communication line 108. It is assumed that the communication methods of the in-vehicle communication devices 110A and 110B are both full duplex, and both the A / N functions are off.

  Here, it is assumed that the in-vehicle communication device 110A is replaced with the in-vehicle communication device 110N. Since the new in-vehicle communication device 110N is initially set with the A / N function turned on, when the in-vehicle communication device 110N is installed and restarted, the A / N function is also activated, and the in-vehicle communication device 110N changes to the in-vehicle communication device 110B. The FLP signal is transmitted. However, since the in-vehicle communication device 110B has the A / N function off, processing corresponding to the FLP signal is not performed. Since the existing in-vehicle communication device 110B transmits the IDLE signal, the new in-vehicle communication device 110N can know the communication speed of the in-vehicle communication device 110B. However, since the in-vehicle communication device 110N does not know the communication method of the in-vehicle communication device 110B, the in-vehicle communication device 110N is temporarily set to the half-duplex mode (case 2: refer to S18 in FIG. 3, Y in S22).

  Since the in-vehicle communication device 110N is set to the half-duplex mode as a result of the first A / N process, the in-vehicle communication device 110N transmits an A / N request to the in-vehicle communication device 110B (see S24 in FIG. 3), and thus the in-vehicle communication. Device 110B is turned on with the A / N function.

  Thus, since both the in-vehicle communication device 110N and the in-vehicle communication device 110B have the A / N function turned on, the A / N processing can be performed again to match the communication methods. When the A / N process is completed, both the A / N functions of the in-vehicle communication devices 110N and 110B are turned off.

  The initial setting of the A / N function of the newly installed in-vehicle communication device 110N should be on, but it works well even if it is off. Since the new in-vehicle communication device 110N cannot record the communication method or the like in the setting information, communication cannot be established when N in S10 and N in S30 to S34 in FIG. Therefore, the process proceeds to S32, and eventually the A / N function is set to ON.

  The communication preprocessing of the in-vehicle communication system 100 has been described above based on the embodiment. According to the present embodiment, it is necessary to execute an A / N process with a large execution cost each time the pre-communication process is executed by following the communication method determined by the previously executed A / N process as it is. Disappear. In addition, when the in-vehicle communication device 110 is replaced, A / N processing is executed between the existing in-vehicle communication device 110 and the new in-vehicle communication device 110. After the setting, the A / N function is turned off. The processing time of pre-communication processing has been successfully reduced while taking advantage of the convenience of the / N function.

  The present invention has been described based on the embodiments. The embodiments are exemplifications, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are within the scope of the present invention. .

  Although the present embodiment has been described with respect to the in-vehicle communication system 100 in a vehicle such as an automobile, the applicable range of the communication method shown in the present embodiment is not limited to this. In particular, this is effective for a high-speed communication system in which the time of several tens of milliseconds to several hundreds of milliseconds required for starting up the A / N function is difficult.

  The in-vehicle communication device 110 may have a function of transmitting an A / N request to the communication partner when it is inferred that the communication partner is in the off setting when the own device is on. When the / N request is received, a function of turning on the A / N function of the own apparatus may be provided.

  DESCRIPTION OF SYMBOLS 100 In-vehicle communication system, 102 ECU, 104 Communication setting part, 106 Communication execution part, 108 Communication line, 110 In-vehicle communication apparatus.

Claims (1)

In an in-vehicle communication system, connected to other in-vehicle communication devices,
A communication setting unit for determining the communication method of the own device to full duplex setting or half duplex setting by inquiring about the communication method of the other in-vehicle communication device, and recording the determined communication method in setting information;
A communication execution unit that executes communication with the other in-vehicle communication device in the communication method recorded in the setting information;
The communication setting unit performs a process of determining the communication method of the own device by inquiring about the communication method of the other in-vehicle communication device, so that the communication method of the own device is a half-duplex setting and the communication When the process for determining the method is the first time, the communication method is again inquired to the other in-vehicle communication device, the communication method of the own device is set to half duplex, and the process for determining the communication method is performed for the first time. in the case other than the case where, after recorded as the setting information to determine the communication mode of the self device, vehicle, characterized that you off set the function of inquiring the communication method of the other vehicle-mounted communication device Communication device.

Images