JPH077957B2 - In-vehicle communication control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an in-vehicle communication control device, and more particularly to an in-vehicle communication control device that forms a data link with other control devices.

[Prior Art] In recent years, a control device for a vehicle that controls various devices has come to perform precise and high-precision control due to its computerization, but recently, a microcomputer or the like has been further incorporated. The intelligentization is progressing. In such a control device, not only simple control symmetrical to the control, but also data can be exchanged with other control devices (including switches) to perform more advanced control as a whole system.

In a vehicle, various electronic devices mounted on the vehicle are controlled by an electronic control device, and a plurality of electronic control devices and switches are data-linked by using a common signal line (communication line) to provide one electronic control device. Attempts have been made to provide other electronic control devices with the data and other control conditions input via the sensor. This data link system is called a LAN (Local Area Network), and as a means for data linking the plurality of electronic control devices to transmit data, so-called CSMA / CD (Carri
er Sense Marutiple Access / Collision Detection) is known.

This CSMA / CD listens before each control device transmits data, and suspends transmission while listening to the transmission by other control devices. To set (ID), distinguish the data type by the ID, or prioritize real-time data, propose a technology to set the priority order of data by setting the priority order of ID (JP-A-61-195453)
(See the official gazette).

[Problems to be Solved by the Invention] However, the above-mentioned conventional techniques have the following problems and have not been sufficient yet.

In other words, in the CSMA / CD method, the ID which is assigned to each data at the time of system design determines the right to win the rest on the communication line. Therefore, data whose ID has been registered as one having a low priority (priority) is lost on the communication line to data having a high priority and refrains from transmission, and is retransmitted after waiting for the communication line to become empty. As a result, low priority data tends to have a long waiting time. However, the data necessary for controlling the driving of the vehicle,
For example, the data required at the time of starting the engine have different degrees of necessity depending on the operating state so that the data may not be needed so much at high speed operation. Therefore, if the priority of data is fixed as in the past,
There has been a problem that it is difficult to improve the feeling of a series of switch operations or to perform fine control according to the running state and the road surface state.

It is an object of the present invention to provide a vehicle communication control device capable of suitably transmitting and receiving data required for vehicle control according to a driving state.

[Means for Solving the Problems] The present invention made to achieve the above object is, as illustrated in FIG. 1, connected to a common signal line M2 via a communication control means M1 for inputting and outputting a signal. In the in-vehicle communication control device that forms a data link with another control device M3 and outputs data to the common signal line M2 based on the transmission right according to a predetermined order in the data link, Order storage means M10 for pre-storing the order of the transmission rights respectively determined according to various driving states of the vehicle, a driving state detecting means M11 for detecting the driving state of the vehicle, and a communication state between the control device M3 Based on the communication state detection means M4 that performs the communication state detection means M4, the order of the transmission rights should be changed when the control device M3 frequently transmits. A ranking change determination unit M5 for disconnection, when it is determined that to make any changes in the hierarchy by 該序 column change determination unit M5 is based on the operating state detected by said operating condition detecting means M11, the ranking memory unit M1
An in-vehicle communication control device is characterized in that it includes an order change instruction means M6 for instructing a change to an order according to the driving state stored in 0.

[Operation] As shown in FIG. 1, the in-vehicle communication control device of the present invention is connected to the common signal line M2 through the communication control means M1 for inputting and outputting signals together with the other control device M3. A common signal line is formed based on a predetermined order (priority) of transmission rights in the data link, which constitutes a data link.
Output data to M2. The order of this transmission right is predetermined in an order of high necessity in accordance with various driving states of the vehicle, for example, when the engine is started or at high speed, whether it is sunny or rainy, daytime or nighttime, etc. The several kinds of orders are stored by the order storage means M10.

If the order set initially is not optimal for the current driving state due to a change in the driving state of the vehicle, the control device having a lower priority may frequently transmit data. Here, the state in which data is frequently transmitted means that a transmission from a control device with a low priority is delayed by a transmission from a control device with a high priority, and the communication line becomes vacant. It means a state in which the lower control device performs transmission again, so that the transmission is performed many times before the transmission is successful. The communication state between such control devices is detected by the communication state detecting means M4. Then, based on this communication state, the control device
When M3 is transmitting frequently, the order change determination means M5 determines that the order of transmission rights should be changed. Then, when it is determined that the order change should be performed, the order change instruction means M6 is, from among the orders stored in the order storage means M10, the current operating state detected by the iron transportation state detection means M11. Based on, select the most appropriate order and instruct to change to that order. As a result, the order of transmission rights is changed to the order most suitable for the current driving state.

That is, in the present invention, when one of the control devices M3 is in the state of frequently transmitting,
Change the order of transmission rights to the order most suitable for the current driving condition.

With such a configuration, if frequent transmission is performed from the control device whose priority should be raised from the current operating state, the priority of the control device can be raised on the occasion of the frequent transmission. On the other hand, even if the control device does not need to raise the priority order from the current operating state, even if the transmission happens to be frequent, the priority order of the control device is not raised. Therefore, unlike the case where the priority order of the control device that has frequently transmitted is simply increased, the communication state is optimized in accordance with the operating state.

Also, if none of the controllers are sending frequently,
Even if the order is not optimal, the order is not changed. This means that if the transmission is successful, it is not necessary to change the order, but rather than simply changing the order by changing the driving state, there will be substantially less unnecessary order change instructions. This is because other processing in each control device can be executed promptly as the processing required for changing the order decreases.

[Embodiment] Next, a preferred embodiment of the in-vehicle communication control device of the present invention will be described in detail with reference to the drawings. FIG. 2 shows a vehicle communication control device as an embodiment of the present invention together with the entire system. This system constitutes a so-called local area network (LAN) for communication, and in this embodiment, the well-known CSMA / CD system is adopted as a bus access system.

As shown, the vehicle has various electronic control units (ECUs)
1, 2, 3, 4 are mounted, and these are connected to the common signal line 5. Also, these ECUs 1 to 4 are connected to the common signal line 5
A communication control circuit 6 is provided for transmitting and receiving signals via the. Furthermore, in addition to the above ECUs 1 to 4, the common signal line 5 is
Various switches 7 and 8 having a communication function are connected. Since the internal configurations of the ECUs 1 to 4 are almost the same, only the air conditioner ECU 1 will be described in detail, and the other parts will be simplified.

(1) Air Conditioner ECU1 This is a control device for monitoring the temperature inside the vehicle and adjusting the temperature inside the vehicle to an appropriate temperature, and is configured as a logical operation circuit including a well-known CPU10, ROM11, RAM12. In addition, the input interface 13 of this air conditioner ECU 1 has an air conditioner EC
A switch group 30 for giving an instruction to U1 and a sensor group 31 for detecting the temperature inside the vehicle are connected, while the output interface 14 is connected with an actuator group 32 such as a drive motor such as a damper (not shown). Furthermore, the common signal line 5
The communication control circuit 6 for controlling the input and output of data to and from is connected to the CPU 10, the ROM 11, the RAM 12, the input interface 13, the output interface 14 and the like via the bus 15.

Then, the ROM 11 stores a combination of the order (priority order) of transmission right of each of the ECUs 1 to 4 and the switches 7 and 8 which will be described later and is changed according to the communication state and the operating state. Further, since this air conditioner ECU1 also serves as a network manager, various commands for instructing the combination of the above priorities are stored in the ROM11, while the other ECUs 2 to 4 correspond to this command. Then, various combinations of the above priorities are stored.

(2) Engine control ECU2 This is a control device that comprehensively controls the fuel injection amount and ignition timing of the engine (not shown), and inputs data from a sensor group 33 such as an intake air amount sensor and a rotation speed sensor, An actuator group 34 such as a fuel injection valve and an igniter is controlled. Then, data is exchanged with the transmission control ECU 3 and the like described later via the common signal line 5 to realize precise engine control such as controlling the output of the engine according to the traveling state.

(3) Transmission control ECU3 is a control device for controlling an on-vehicle automatic transmission (not shown), and a gear ratio based on an input from a sensor group 35 such as a sensor for detecting a hydraulic oil pressure for detecting a shift position. The actuator group 36 such as a hydraulic valve for switching between is controlled to be driven.

(4) Suspension ECU4 A control device that switches the characteristics of a suspension (not shown) according to the running state, and controls an actuator group 38 such as a hydraulic valve based on an input from a sensor group 37 that detects vehicle height and the like. To do. This suspension control ECU4
When the throttle valve is suddenly opened, the common signal line 5
Since this is notified from the engine control ECU2 via
Perform precise control such as hardening the characteristics of the shock absorber.

In addition to the ECUs 1 to 4, the common signal line 5 includes, for example, switches such as a wiper switch 7 and an automatic drive switch 8 as well as a mirror, seat, telescopic or tilt steering system switch (not shown). Are connected via the communication control circuit 6.

Here, as shown in FIG. 3, the communication control circuit 6 included in the air conditioner ECU 1 and the like is provided with a control logic 6c including a RAM 6a and a ROM 6b. The control logic 6c includes a driver 6d that transmits a signal to the common signal line 5, a receiver 6e that receives a signal from the common signal line 5, and a serial input / output unit (SIO) 6f that inputs / outputs serial data. A parallel input / output unit (PIO) 6g for inputting / outputting parallel data is connected via the bus 6h. Further, the communication control circuit 6 is provided with a frequency dividing circuit 6i for frequency dividing the clock based on the set baud rate.

Next, the control performed by the in-vehicle communication control device of the present embodiment will be described based on the explanatory views of FIGS. 4 and 5 and the flowcharts of FIGS. 6 and 7.

In the present embodiment, as shown in FIG. 4, the air conditioner ECU1 functions as a network manager and determines the order (priority order) of its own transmission right according to the communication state between the ECUs 1 to 4 and various operating states. Along with the change, a control signal (command) for instructing the other ECUs 2 to 4 to change the priority order is transmitted. ECUs 2-4 different from this priority
The data signal (frame) transmitted from the switches 7 and 8 indicates the right to win in the event of collision on the common signal line 5.

As shown in FIG. 5, the frame includes a start flag indicating the beginning of the signal, an identifier (ID) indicating where the signal is transmitted from, a data byte that is the content of the signal, a CRC for detecting an error, It is composed of an end flag indicating the trailing end of the signal. Among these, a signal indicating the priority order is recorded in the above ID.

Since the priority of each switch 7 and 8 cannot be changed, the ECU
By changing the priority levels of 1 to 4, the priority levels of the switches 7 and 8 can be changed substantially.

Next, a description will be given based on the flowchart of FIG.

First, as shown in the figure, in step 100, it is determined whether or not one minute or more has elapsed from the start of control. If a negative determination is made here, the process proceeds to step 110 to determine whether the initialization of the priority order is completed. To determine. If an affirmative determination is made here, the process returns to step 100. On the other hand, if a negative determination is made, the process proceeds to step 120, the priority order is initialized, and the process returns to step 100.

That is, the processing of steps 100 to 120 is 1
If the initial settings have not been made in less than a minute, ECU1-4
This is a process for performing initial settings such as.

If it is determined in step 100 that one minute or more has elapsed, the process proceeds to step 130.

In step 130, it is determined whether or not 5 seconds or more have passed since the previous step 130, and if it is determined that 5 seconds or more have passed, the process proceeds to step 140.

In step 140, based on the signal from the light amount sensor,
Determine whether the surroundings are bright or dark. If it is determined that it is dark, the process proceeds to step 150.

In step 150, it is determined based on the signal from the wiper stitch 7 whether the surrounding rain is fine. That is, if the wiper switch 7 is on, it is determined to be rain, and if it is off, it is determined to be sunny. If it is determined that it is raining, the process proceeds to step 160.

In step 160, it is determined whether the vehicle is traveling smoothly based on the signal from the vehicle speed sensor. That is, it is determined whether or not the speed of the vehicle is repeatedly accelerated and decelerated within a predetermined time, and thereby the traveling state of the vehicle is determined. If it is determined that the vehicle is traveling smoothly, the process proceeds to step 170.

In step 170, it is determined whether the speed of the vehicle is equal to or higher than a predetermined value based on the signal from the vehicle speed sensor. If the speed is high, the process proceeds to step 180.

In this step 180, the devices (nodes) of the ECUs 1 to 4 and the switches 7 and 8 that have transmitted a predetermined number of times in the past 5 seconds.
It is determined whether or not there is a node, and if there is a node that has transmitted frequently over a predetermined number of times, the process proceeds to step 190. On the other hand, if there is no node that has transmitted more than the predetermined number of times, the process returns to step 130.

Note that this step 180 and the following steps 190 and 200 collectively display the determination of the number of transmissions and the processing performed based on the determination in order to simplify the explanation of the flowchart. Processing is performed through different routes depending on the determination of the driving state and the determination of the communication state.

In step 190, the air conditioner ECU 1 which is the network manager transmits a command for changing the priority order according to the number of transmissions of each node and the operating state determined in steps 140 to 170. When sending this command, the priority of the network manager itself is changed if necessary.

In the following step 200, in response to the command from the network manager, each of the ECUs 2 to 4 performs a process of changing its own priority order, and returns to the above step 130 to repeat the same process.

In addition, when the affirmative judgment is made in steps 140 to 170,
For example, at night, it is determined that it is raining and that the vehicle is traveling smoothly at high speed. Therefore, for example, it is conceivable to raise the priority of the control device used for the anti-brake system (ABS).

Next, the other processing of FIG. 6 will be described, but since it is almost the same as the processing described above, it will be briefly described.

First, if a negative determination is made in step 160 or step 170, the process proceeds to step 180 to determine the number of times of node transmission. Based on that decision, step 190,200
Go to to change the priority of the transmission right, or step
Return to 130.

If a negative decision is made in step 150, step 2
In step 10, it is determined whether or not the vehicle is running smoothly, and in step 220, it is determined whether or not the speed is equal to or higher than a predetermined speed. In each case, the process proceeds to step 180. Then step 19 as above
Proceed to 0,200 or step 130.

Further, the step 2 which is judged negative in the above step 140 and proceeds.
In 30, it is determined whether it is raining, and if a positive determination is made here,
In steps 240 and 250, after determining the respective operating states as in steps 160 and 170, the process proceeds to step 180. On the other hand, if a negative decision is made in step 230, step 26
After determining the same operating condition at 0,270, proceed to step 180
Proceed to.

Next, regarding the processing performed in step 200 described above,
A detailed description will be given based on the flowchart of FIG.

As shown in the figure, when a command is sent from the network manager, each of the ECUs 2 to 4 firstly executes step 300
At, it is determined whether or not the command is received. If an affirmative decision is made here, the routine proceeds to step 310, where the ROM 11 of the ECUs 2 to 4 is
Refer to the combination of priorities corresponding to the above commands stored in, to find the corresponding combination, and step 320
Proceed to.

In step 320, it is determined whether or not the newly obtained priority of the self is the same as the current priority of the self, and if it is affirmatively determined to be the same, the priority is not changed. This process is once terminated, and if it is determined to be different, the process proceeds to step 330.

In step 330, the current priority order is changed to a new priority order, and this processing is once terminated.

In other words, the network manager monitors the communication status,
If there is a node that has transmitted frequently more than a predetermined number of times, which ECU 2 to 4 or switch will be used depending on the driving state of the vehicle.
It is determined whether the priority of 7, 8 should be raised or lowered, and a predetermined command is transmitted to the other ECUs 2 to 3 according to the determination. Then, the ECUs 2 to 4 receiving the command refer to the combination of the priorities corresponding to the above commands stored in the ROM 11 of their own, and change their own priorities in accordance with this command.

As described above, in this embodiment, the ambient brightness, the clear rain, the running state and speed of the vehicle are detected to determine the operating state of the vehicle, and the number of frames sent from each node is detected, It determines the communication status of ECUs 1 to 4 and switches 7 and 8.

Therefore, the priority of the transmission right of the ECUs 1 to 4 and the switches 7 and 8 can be changed at any time and optimally set according to the operating state and the communication state. As a result, the priority of the data most needed to control the driving at that time can be raised, so that the necessary data can be sent and received promptly,
The vehicle can be controlled quickly and accurately.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and it goes without saying that the present invention can be implemented in various modes without departing from the scope of the present invention. .

For example, in the present embodiment, the air conditioner ECU1 is used as the network manager, but this network manager may be made to serve also to the ECU having a relatively large control, and there is no particular limitation. For example, the ECU for controlling the digital meter or the ECU for controlling the position of the seat may be concurrently used.

[Effects of the Invention] As described in detail above, the in-vehicle communication control device of the present invention sets the order of the transmission right to the current driving state when any one of the control devices is in a state of frequent transmission. Change the order accordingly. Therefore, if frequent transmission is performed from the control device that should raise the priority, while the priority of the control device increases, even if the control device that does not need to raise the priority frequently transmits. The priority of the control device is not increased. Further, if none of the control devices transmits frequently, even if the current order is not optimal, the unnecessary order change is not substantially performed, and other processing in each control device can be quickly executed.
As a result of these, the optimum communication state according to the driving state is immediately set as necessary, so that the vehicle can be quickly and appropriately controlled, and fine control according to the running state and the road surface state can be performed, and the switch operation The feeling, etc. of will also be improved.

[Brief description of drawings]

FIG. 1 is an exemplary diagram of a basic configuration of the present invention, FIG. 2 is a system configuration diagram of an embodiment, FIG. 3 is a schematic configuration diagram of a communication control circuit, and FIG. 4 is a basic configuration of an electronic control unit and a switch. FIG. 5 is an explanatory view showing the structure of data, FIG. 6 is a flow chart showing the overall control of this embodiment, and FIG. 7 is a flow chart showing the processing for changing the order of transmission rights. M1 ...... Communication control means M2 ...... Common signal line M3 ...... Control device M4 ...... Communication status detection means M5 …… Order change determination means M6 …… Order change instruction means M10 …… Order storage means M11 …… Operating status detection Means 1,2,3,4 …… ECU 6 …… Communication control circuit 7 …… Wiper switch 8 …… Auto drive switch

Claims (1)

[Claims] 1. A data link is connected to a common signal line via a communication control means for inputting and outputting a signal, forms a data link with another control device, and a transmission right according to a predetermined order is established in the data link. On the basis of the above, in the in-vehicle communication control device for outputting data to the common signal line, an order storage means for pre-storing the order of the transmission rights respectively determined according to various operating states of the vehicle, and an operating state of the vehicle Based on the driving state detecting means for detecting, the communication state detecting means for detecting the communication state between the control devices, and the communication state detected by the communication state detecting means, the control device frequently transmits. In this case, the order change judging means for judging that the order of the transmission right should be changed, and the case where the order change is judged by the order change judging means. An order change instructing means for instructing a change to an order according to the operating state stored in the order storing means based on the operating state detected by the operating state detecting means. Communication control device.