JPH0758962B2 - Control device having communication function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a control device having a communication function which constitutes a data link together with another control device.

[Prior Art] In recent years, electronic control devices, particularly digitization and densification of control by logical operation using a microcomputer or the like, have been attempted to improve control safety and reliability. For example, in-vehicle control devices are known to have a diagnosis function that detects when a connected sensor or actuator fails, and it also communicates with a dedicated electronic control device for diagnosis. Thus, a device that informs the user of the details of the failure has been put into practical use. On the other hand, a failure of the electronic control unit itself, such as a central processing unit (CP
If a runaway of (U) occurs, a watchdog timer or the like detects this and switches to a backup circuit or resets to ensure safety.

[Problems to be Solved by the Invention] However, in such a control device, even if the failure of the sensor or the like can be notified by sending a diagnostic code, etc., if the control device main body fails, the user is informed of this. There was a problem that I could not do it. This is a particular problem when a plurality of control devices work together to perform higher and more precise control as a whole.

For example, in a vehicle or the like, various electronic devices mounted on the vehicle are controlled by an electronic control unit, and a plurality of electronic control units are data-linked using a common signal line, and one electronic control unit is connected via a sensor or the like. With a configuration that provides input data and other control conditions to other electronic control units, the impact of failure of one electronic control unit on the other cannot be overlooked and must be detected reliably. Is required. In such cases, depending on the power supply mode and the presence or absence of operation products, some control devices do not operate from the beginning or do not participate in the data link. Therefore, it is not possible to easily detect an abnormality in the control device, and an abnormality is detected. If so, special equipment and signal lines are required. As a result, conventionally, the abnormality of the control device is processed only in the control device, and it is difficult to inform the abnormality to the outside and utilize it for maintenance or the like.

The present invention has been made for the purpose of solving the above-mentioned problems, and particularly for the purpose of providing a control device having a communication function capable of suitably detecting an abnormality occurring in a data-linked control device.

Structure of the Invention [Means for Solving Problems] In order to achieve the above object, the present invention has the following structures as means for solving the problems. That is, as illustrated in FIG. 1, the common signal line is connected via the communication means M1 for inputting / outputting signals.
A control device having a communication function that is connected to M2 to form a data link with another control device M3, through the communication means M1, among other control devices M3 connected to the common signal line M2. Control device M3 for predetermined abnormality determination
To the control device that called the communication to
When the response to the call for communication is input through the communication means M1 when the abnormality determination condition regarding M3 is satisfied, the fact that the response is received corresponds to each of the other control devices M3. If there is no response from the other control device M3 to the call for the communication, the response experience storage means M4 to store the response experience based on the stored contents of the response experience storage means M3, even once in the past. From the response experience determination means M5 for determining whether or not there is a response from the control device M3, and if the response experience determination means M5 determines that there has been a response from the control device M3 even once in the past, a state in which the communication call is not responded This is the configuration of the control device having a communication function, which is provided with the abnormality determination means M6 that determines that the control device is abnormal when the control device continues for a predetermined number of times.

Here, the communication means M1 is for inputting / outputting signals to / from the common signal line M2.When the common signal line M2 is a serial line, the serial / parallel communication is performed in accordance with the data processing inside the control device. A configuration having an exchange function can be considered.

The response experience storage means M4 stores data, and various configurations such as a semiconductor memory and a magnetic recording device can be considered. Alternatively, a shift register may be used. It is preferable that a non-volatile memory is used or the memory is backed up by a battery or the like so that the occurrence of a failure can be held regardless of the state of power supply. Furthermore, the response experience storage means M4 may be prepared for each power supply mode.

The response experience determination means M5 and the abnormality determination means M6 can be configured as a logical operation circuit using a microcomputer or the like, or as a logic circuit using a shift register and a flip-flop or the like.

In addition, in the data link, all the control devices include the response experience storing means M4, the response experience determining means M5, and the abnormality determining means.
It is not necessary to have the same configuration as the control device of the present invention including M6, and it is conceivable that the control device is realized as a control device specialized for a diagnostic device or as a configuration incorporated in a part of a main control device. .

[Operation] The control device having the communication function of the present invention having the above configuration constitutes a data link together with another control device M3.
In this data link, a communication device M3 is connected to the common signal line M2 via the communication means M1, and a communication device is called to the control device M3 of a predetermined abnormality determination target in the other control device M3, and the control device M3 has called for the communication. If the abnormality determination condition in is satisfied, the communication means responds to the communication call.
When inputting via M1, the response experience memory means M4
The response is stored for each of the other control devices M3.

On the other hand, the response experience determination means M5, if there is no response from the other control device M3 to the call of the communication, based on the stored content of the response experience storage means M4, even once in the past response from the control device M3 Determine whether there was. Then, the abnormality determination means M6, if it is determined by the response experience determination means M5 that there was a response from the control device M3 even once in the past, if the state of not responding to the call for communication continues for a predetermined number of times, the It is determined that the control device M3 is abnormal.

Therefore, according to the control device having the communication function of the present invention, the control device is physically in a state in which communication is possible for a while (for example, when it is installed and physically If it is determined that the communication device is not in a non-communicable state and the communication is not responded to for a predetermined number of times despite such a communication possible state, the control device is abnormal. By determining that there is, a reliable abnormality determination can be performed.

For example, there is a control device M3 that does not operate from the beginning or does not participate in the data link depending on the power supply mode or the presence or absence of optional items, and there is an optional control device that is not installed from the beginning. In such a case, it is not unusual for those control devices M3 not to respond, so
On the contrary, if these are judged to be abnormal, they will be erroneous judgments.
In that respect, in the present invention, the fact that the control device M3 that does not participate in the data link or the optional control device M3 that is not mounted from the beginning does not respond itself does not participate in the abnormality determination, and actually causes an abnormality (that is, Only the control device M3 that does not respond even though it is in the communicable state can be accurately determined. Further, even when such an optional control device M3 is installed later, it is possible to continue the processing as it is without changing the program or data, including the determination of the abnormality of the added control device M3, After all, a reliable abnormality determination can be performed.

[Embodiment] Next, in order to further clarify the configuration of the present invention, a preferred embodiment of a control device having a communication function will be described with reference to the drawings. FIG. 2 is a schematic configuration diagram showing the control device having this communication function together with the entire system.

As shown in the figure, the vehicle is equipped with the following seven electronic control units (ECUs), which are connected to a common signal line 1. Further, these electronic control devices are configured to be supplied with power from the battery 5 via the ignition switch 3, and operate in respective power supply modes that differ depending on the position of the ignition switch 3. Since the internal configuration of each ECU is almost the same except for the presence or absence of the EEPROM, only the diagnosis ECU 10 will be described in detail, and the others will be omitted.

(1) Diagnostic ECU10: This is a control unit that monitors the malfunctions of other ECUs mounted on the vehicle and informs them to the outside. Well known CPU11, ROM1
It is configured as a logical operation circuit including 2, RAM 13a and EEPROM 13b. The diagnostic ECU 10 further includes a serial I / O port (SIO) 14 for inputting / outputting data to / from the common signal line 1, a CRT display circuit 16 for displaying information on a display device (hereinafter referred to as CRT) 15, and a DIALOG. It is equipped with an input port 18 for reading the state of the switch group 17 for giving an instruction to the Gnostic ECU 10, a power supply unit 19 for supplying a stabilized power supply voltage VC to the entire device by receiving a battery voltage VB from the power supply line, and the like. . In addition, from the power supply unit 19, a mode of power supply, in other words, the position of the ignition switch 3 (IG, A
A signal line for determining (CC, OFF, etc.) is connected to the input port 18.

(2) Engine control ECU 20: A control device that comprehensively controls the fuel injection amount, ignition timing, etc. of the engine (not shown), and inputs data from a sensor group 25 such as an intake air amount sensor and a rotation speed sensor. , A group of actuators 28 such as fuel injection valves and igniters. Transmission control described later via the common signal line 1
It realizes precise engine control by exchanging data with the ECU and controlling the engine output according to the running condition.

(3) Skid control ECU 30: a wheel control unit that controls the sideslip of the vehicle due to wheel locks, and changes the braking force by inputting data from a sensor group 35 that detects the rotation speed of each wheel. An actuator group 38 such as a hydraulic valve that changes the cylinder pressure is controlled. Data such as vehicle speed is transmitted to the skid control ECU 30 from a transmission control ECU described later.

(4) Transmission control ECU 40: a control device that controls an on-vehicle automatic transmission (not shown), and a sensor that detects a shift position, a sensor that detects an operating hydraulic pressure, and the like based on an input from the sensor group 45. It drives and controls an actuator group 48 such as a hydraulic valve that switches a gear ratio.

(5) Air conditioner ECU50: A control device for controlling an air conditioner (not shown), which is based on an input from a sensor group 55 that detects the temperature inside and outside the vehicle and the designation of a ventilation mode, a compressor, a blower motor, and a damper. An actuator group 58 such as an opening control motor is controlled. This air conditioner ECU50 has a common signal line 1
For example, data is output to the engine control ECU 20 via the, and a request for idle-up or the like is transmitted.

(6) Suspension control ECU 60: A control device that switches the characteristics of a suspension (not shown) according to the running state, and based on an input from a sensor group 65 that detects vehicle height and the like, an actuator group 68 such as a hydraulic valve 68. To control. This suspension control ECU60
When the throttle valve is suddenly opened, this is notified from the engine control ECU 20 via the common signal line 1, so that precise control such as hardening the characteristics of the shock absorber is performed.

(7) Auto-drive ECU70: A control device that performs control to keep the traveling speed of the vehicle at a constant value.
D) An actuator 78 that adjusts the throttle opening for auto drive is controlled based on an input from a switch group 75 such as a switch and a brake switch that detects a brake operation. In addition, the ECU 70 uses the vehicle speed information or the like transmitted from the transmission control ECU 40 via the common signal line 1 to instruct the engine control ECU 20 to correct the engine output, or in some cases, the transmission ECU 40
The speed of the vehicle is kept constant by performing processing such as outputting a gear shift command to.

The outline of the configuration of each of the ECUs 10 to 70 has been described above. The EEPROM 13b provided in the diagnostic ECU 10
Is not implemented on other ECUs 20-70. EEPROM 1
The electrically erasable programmable ROM 3b is a type of memory that can be freely written and read, but its contents are not erased even when the power is turned off. In this embodiment, this EEPROM 13b is the response experience storage means M
Acts as 4 and remembers the response experience of other control devices 20-70.

Also, an address (token address) indicating the mounting status of each of the ECUs 10 to 70 and the transmission right to the common signal line 1
The numbers are shown in Table 1 below.

Here, the token address Tad is a number given in advance for each ECU, and is the data given to the head of the data output by the ECU that has acquired the transmission right. The data output by each ECU has a predetermined format and extends from the first word to the n-th word as shown in FIG. The upper 5 bits of the first word are the above-mentioned token address Tad, and the lower 3 bits thereof represent the word length (n-2) of the data. The data from the second word to the (n-1) th word indicates predetermined data D1 to Dn-2 to be sent to another ECU, for example, data such as a vehicle speed signal input via a sensor switch group. . The second word is
It is a flag data representing a transmission request. The contents of the flag data will be described later. One word as a so-called checksum CS is added to the end of the message. This checksum CS is the sum of the values indicated by each word of the message [the value indicated by the header HD + the data D [D1 to Dn-2].
Value + checksum CS value] is set to FF (hexadecimal number). Each ECU uses this checksum C
The S is used to determine whether the received message was sent correctly.

Although various methods have been proposed for acquiring the control right to output data to the common signal line 1, that is, the transmission right,
In this embodiment, the first data output to the common signal line 1
When the token address Tad in the word is its own token address Tad-1, it is predetermined to acquire the transmission right next. That is, in this embodiment, the ECUs 10 to 7
0 is data-linked by a so-called token bus and obtains a transmission right to transmit data. Each transmission right
Since the ECU performs input / output while incrementing the token address Tad, the token address shown in Table 1
Orbit all ECUs within a predetermined time in the order according to Tad.

Note that the suspension control ECU 60 that is not installed as an option cannot acquire the transmission right, so the air conditioning ECU 50 that transfers the transmission right to the suspension control ECU 60.
Detects this, and after a certain trial, token address Tad for delegating the transmission right to the suspension control ECU 60.
= 3 is skipped, and the token address Tad = 4 of the auto drive ECU 70 that is the control device that should acquire the transmission right next time
Is configured to output. A detailed description of the processing relating to the transfer of the transmission right will be omitted.

Next, the abnormality determination processing performed by the diagnosis ECU 10 will be described with reference to the flowcharts of FIGS. 4 (A) and 4 (B).

This process performed by the diagnosis ECU 10 is a process for obtaining a response (Fig. 4 (A)) to the ECU that is trying to make a determination, and a process for waiting for a response from the ECU (4th process).
(B)).

As an example, a process for the auto drive ECU 70 will be described. The process for requesting a response from the autodrive ECU 70 is started by first determining whether or not the operating conditions of the autodrive ECU 70 are satisfied (step 100), as shown in the flowchart of FIG. The operating conditions are
It is considered to be established when the ignition switch 3 is set to the ignition IG position and the auto drive switch is turned on. If the operating conditions are met,
Further, it is determined whether or not it is the timing to perform the fail determination (step 110). Since the fail determination is performed once every few seconds, it is possible to determine whether the determined timing has been reached by the state of the interval timer incorporated in the CPU 11.

If both conditions of steps 100 and 110 are not satisfied, it is determined that it is not necessary to make a fail judgment, and the routine is exited by exiting to "NEXT". On the other hand, if both conditions are met, a fail judgment is made. As step 12
Move to processing 0 or less.

In steps 120 and below, a flag requesting a message is set to the auto drive ECU 70 (step 12
0), a process of outputting this to the common signal line 1 through the SIO 14 is performed (step 130). The flag requesting a message is assigned to the lower 6 bits of 8 bits for each ECU as follows.

This 1-byte flag data is sent together with the token as the second word in the above-mentioned message.

The ECU connected to the common signal line 1 always reads the data on the common signal line 1 except when sending a message by itself. Moreover, if the flag of the second word is checked and its own flag is set,
In response to this, predetermined data is output to the common signal line 1 within a predetermined time.

Therefore, the diagnosis ECU 10 outputs a message by the above-mentioned data transmission processing routine and then activates an abnormality determination routine shown in FIG. 4 (B) to obtain a response.
The following processing is performed according to the operation from the ECU.

In this routine, first, it is determined whether or not the message request flag is set (step 200), and the operating condition of the auto drive ECU 70 (the ignition switch is set to I
It is determined whether or not G and A / D switch is on (step 210). That is, auto drive ECU
Conditions for the determination of 70 the abnormality (failure) is not less to determine whether the established, if not satisfied any of the conditions in each step, the value in the counter CNT ₀ 0
Is set (step 220), and this routine is finished as it is. On the other hand, if the message request flag is set in the routine shown in FIG. 4 (A) and the operating conditions of the auto drive ECU 70 are satisfied, the process proceeds to step 230 and below to monitor the common signal line 1. Then, in response to the message request, the determination as to whether or not the automatic drive ECU 70 has transmitted data is repeated until the time is over (steps 230 and 240).

If the data is transmitted before the elapse of the predetermined time Tov, it is determined that the auto drive ECU 70 is connected to the common signal line 1 and normally participates in communication and sets the connection flag to 1. Perform (step 250). This connection flag is provided in a predetermined area in the EEPROM 13b, and the lower 6 bits correspond to each of the ECUs 20 to 70.

Here, ²⁵ bits are set to 1. Auto drive
If it is confirmed that the ECU 70 responds and participates in the communication, it is not necessary to request the data transmission any more, so the message request flag is cleared to zero (step 26
0), exit to "NEXT" and end this routine. This state is shown in Section I of FIG.

On the other hand, when the auto drive ECU 70 does not send data within the predetermined time Tov, it is assumed that the ECU 70 does not participate in the communication, and it is first confirmed whether or not the connection flag of the auto drive ECU 70 is set to the value 1. Do (step
270). Since the connection flag is stored in EEPROM 13b, if this value is not 1, auto drive EC
U70 judges that it has never participated in communication in the past, that is, it is an option and is not standard equipment, and clears the message request flag as in the response time described above (step 260). , This routine ends.

If it is determined in step 270 that the connection flag in the EEPROM 13b has the value 1, the value of the counter CNT ₀ is incremented by 1 (step 280), and the value C of this counter is further incremented.
It is determined whether NT ₀ is greater than or equal to a predetermined value CS (value 3 in this embodiment) (step 290). That is, auto drive ECU70
However, even if it has participated in communication even once in the past (connection flag = 1) but does not respond to the request for response, it is considered that some abnormality has occurred including the communication system, and erroneous detection due to noise etc. in the communication system. In order to eliminate the possibility of the above, when this state continues for CS times or more in succession, the auto drive ECU 70 determines that it is a failure. This situation is shown in Section II of FIG. In this case, the occurrence of the fail is stored in a predetermined area of the EEPROM 13b (step 300). Moreover,
The message request flag is cleared as in each case described above (step 260), and this routine ends.

In this embodiment, the CPU of the diagnosis ECU10
11 corresponds to the response experience determination means M5 and the abnormality determination means M6,
Of the processing executed by the CPU 11, the processing of FIG. 4A and the processing of steps 200 to 270 in FIG. 4B correspond to the processing as the response experience determination means M5. Also, steps 280, 29
The process of 0 corresponds to the process as the abnormality determination means M6.

According to the present embodiment configured as described above, if each ECU participates in the communication even once, it is stored in the nonvolatile EEPROM.
It is stored in 13b, and when it does not participate in the communication thereafter (when it does not respond to the message request of the diagnostic ECU 10 in this embodiment), it is connected to the common signal line 1 when the state continues for three times or more. If an abnormality occurs in the ECU 20 to 70, this can be stored in the EEPROM 13b.
Therefore, even if there is an optional ECU that is not implemented from the beginning, the fact that the ECU does not respond does not contribute to the determination of abnormality, and it is possible to accurately detect only the ECU that actually caused the abnormality. it can. Further, even if such an optional product is mounted later, the processing can be continued without changing the program and data, and there is no problem in detecting the occurrence of an abnormality.

The ECU abnormality detected in this way is stored and retained in the EEPROM 13b, so by operating the switch group 15 of the diagnosis ECU 10, each data-linked
The failure of the ECUs 20 to 70 can be known very easily, and as a result, the maintainability of each vehicle-mounted ECU is significantly improved.

Further, in the data communication within the token bus using the common signal line 1, it is easy to eliminate the influence of the abnormal ECU and perform the subsequent processing. Therefore, it is possible to make full use of the advantages of the token bus and perform highly reliable communication. Furthermore, in the present embodiment, the abnormality is determined only when the ECU does not respond three times or more, and the influence of noise on the common signal line 1 can be removed.

In addition, the connection flag and the EEPR that stores this when an error occurs
The area in the OM 13b may be provided for each power supply mode for the ECU (here, IG or ACC), and in this case, the occurrence of abnormality can be discriminated for each mode.

Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and is applied to a data link configured such that each control device outputs predetermined data by itself at regular time intervals. It is needless to say that the present invention can be implemented in various modes without departing from the gist of the present invention, such as the configuration described above or the configuration in which some control devices in the data link have the same abnormality detection function.

EFFECTS OF THE INVENTION According to the control device having the communication function of the present invention described in detail above, it is possible to reliably detect the occurrence of an abnormality in the control device forming the data link with an extremely simple configuration. Produce an effect. Moreover, since it is possible to easily detect an abnormality in the control device regardless of whether or not each control device forming the data link is mounted, each control device connected to the data link by an option, such as a vehicle, can be easily detected. It is more suitable for different cases.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating the basic configuration of the present invention, FIG. 2 is a block diagram showing the configuration of a control device having a communication function as one embodiment of the present invention, and FIG. 3 is a format of transmission data. FIGS. 4A and 4B are flowcharts showing a process performed for abnormality determination, and FIG. 5 is an explanatory diagram showing a state of abnormality detection. M1 ...... Communication means M2 ...... Common signal line M3 ...... Other control device M4 ...... Storage means M5 ...... Response experience judgment means M6 ...... Abnormality judgment means 1 ...... Common signal line 10 ...... Diagnostic ECU 13b ... … EEPROM 20 …… Engine control ECU 30 …… Skid control ECU 40 …… Transmission control ECU 50 …… Air conditioner ECU 60 …… Suspension control ECU 70 …… Auto drive ECU

Front page continued (72) Inventor Katsunori Ito 1-1, Showa-cho, Kariya Aichi Prefecture, Nihon Denso Co., Ltd. (72) Inventor Takao Saito 1, Toyota-cho, Aichi Prefecture Toyota Motor Co., Ltd. (72 ) Inventor Tetsuo Tanikawa 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (56) References Japanese Patent Laid-Open No. 59-144240 (JP, A)

Claims (4)

[Claims] 1. A control device having a communication function, which is connected to a common signal line via a communication means for inputting / outputting a signal and constitutes a data link with another control device, wherein the communication means is used. , Calling a communication to a control device of a predetermined abnormality determination target in the other control device connected to the common signal line, when the abnormality determination condition for the control device calling the communication is established, When a response to a call for communication is input via the communication means, a response experience storage means for storing that the response has been made corresponding to each of the other control devices, and the other for responding to the call for communication When there is no response from the control device, based on the stored contents of the response experience storage means, a response experience determination means for determining whether or not there is a response from the control device even once in the past, If the response experience determination means determines that there has been a response from the control device even once in the past, if the state in which the control device does not respond to the communication call continues for a predetermined number of times, the control device determines that the control device is abnormal A control device having a communication function, comprising: 2. The data link according to claim 1, wherein the data link is configured to obtain the transmission right transmitted according to a predetermined order and output the data to the common signal line via the communication means. A control device having a communication function. 3. A control device having a communication function according to claim 1, wherein a plurality of the response experience storage means are provided for each mode of power supply to the other control device. 4. The communication function according to any one of claims 1 to 3, wherein the response experience storage means is a backup memory that retains stored contents regardless of a power supply state. Control device having a.