JPH04275740A - On-vehicle multiplex transmission device - Google Patents

Abstract

PURPOSE:To safely control an output complementary device without giving influence even if a controller is abnormal in an on-vehicle multiplex transmission device which multiplex transmitting a message between plural controllers. CONSTITUTION:An input/output interface 21, CPU 22, communication LSI 24 and a power source circuit 25 constitute a first signal processing means. The input/output interface 21 and communication LSI 23 constitute a second signal processing means for backup when communication is abnormal. Since the second signal processing means is a simple operation system for controlling only the complementary device which is necessary for safety when communication is abnormal, the reliability is much higher than that of the first signal processing means. The signal processing means are selectively connected to transmission lines 6 and 7 by contact points 27a, 27b, 28a and 28b which are interlocked with a relay 29.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle multiplex transmission device that controls the drive of a load connected to each controller by multiplexing messages between a plurality of controllers distributed within the vehicle. In particular, the present invention relates to a vehicle-mounted multiplex transmission device having a backup function in case of abnormality in the controller.

0002

2. Description of the Related Art A multiplex transmission system has been known for simplifying wiring connections between electrical components for automobiles. As shown in FIG. 4, this multiplex transmission device has CP
A plurality of controllers 31 each having a built-in main control unit such as a central processing unit (U) are disposed in a distributed manner in the vehicle, and each controller 31 has output auxiliary equipment 32 consisting of loads such as various lamps and motors, and outputs thereof. An input auxiliary machine 33 consisting of load drive command means such as a switch and a sensor for generating a drive command signal for the auxiliary machine 32 is connected, and each controller 31 is connected by a transmission line 34. In this device, messages are transmitted via a transmission line 34 between a controller 31 to which an input auxiliary device 33 is connected and a controller 31 to which an output auxiliary device 32 driven by the input auxiliary device 33 is connected. By this, the output auxiliary machine 32 is controlled. Further, in this device, by multiplexing a plurality of messages on the transmission line 34, the controller 3
We are trying to simplify the wiring harness between 1 and 1.

0003

In this type of system, loads essential for maintaining safety, such as brake lamps, headlamps, and turn lamps, are connected as output auxiliary equipment. Therefore, it is necessary to use some method to prevent these loads from malfunctioning or malfunctioning due to controller failure. In particular, the communication LSI included in each controller has a large number of gates and failures occur more frequently than other elements, and when a failure occurs, communication cannot be performed and output auxiliary equipment cannot be controlled at all. Therefore, there is a problem that the influence is large.

[0004] Therefore, the self-diagnosis function of each controller and the monitoring function of the monitoring controller are used to detect abnormalities in each controller, and when an abnormality occurs, based on its own backup flow, the load that is essential for maintaining safety is detected. A system is also known in which the motor is operated in a fixed manner in a direction that does not reduce safety. However, such a system has disadvantages in that the burden on the software of each controller increases and the operation in the event of an abnormality must be fixed. The present invention has been made in view of such problems, and an object of the present invention is to provide an in-vehicle multiplex transmission device that can control output auxiliary equipment without affecting safety even when the controller is abnormal. With the goal.

[0005]

[Means for Solving the Problems] An on-vehicle multiplex transmission device according to the present invention includes a plurality of controllers distributed in a vehicle, loads connected to these controllers, and means for generating drive command signals for the loads. an auxiliary device, and a transmission path connecting the controllers, and performs multiplex transmission of messages between the controllers via the transmission path to control the drive of the load via the controller. In the multiplex transmission device, a first controller to which a specific load is connected and a second controller to which a means for generating a drive command signal for the load is connected,
A first signal processing means that performs normal communication between these controllers, and a second signal processing means for backup that performs communication for controlling only the specific load between these controllers.
When the signal processing means and the first and second controllers are normal, the first signal processing means and the transmission line are connected, and when at least one of the first and second controllers is abnormal. The apparatus is characterized in that it includes switching means for connecting the second signal processing means and the transmission line when the transmission path is reached.

[0006]

[Operation] According to the present invention, the first controller to which a specific load, particularly a load that affects safety, is connected and the second controller to which a means for controlling the specific load is connected operate normally. When this is the case, the first signal processing means performs message communication via the transmission path, and when at least one of the first and second controllers becomes abnormal, the second signal processing means performs message communication via the transmission path. Messages are communicated via the Internet. Therefore, even if the controller fails, the control of a specific load will not be affected.

[0007] The second signal processing means may be the same as the first signal processing means, but if the second signal processing means is for controlling only the load essential for safety, for example, the second signal processing means may be the same as the first signal processing means. The configuration can be simplified. In this case, the second signal processing means may be directly driven by a battery without using a power supply circuit, have fewer input terminals than the first signal processing means, or have a simpler protocol. It is desirable that the failure probability is lower than that of the first signal processing means, such as by having a small number of gates.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 2 is a block diagram showing the overall configuration of a multiplex transmission apparatus according to an embodiment of the present invention. That is, a plurality of controllers 1a, 1b, 1c,
1d and 1x are arranged in a distributed manner. These controllers 1a to 1x are interconnected via a transmission line 2. Each of the controllers 1a to 1x includes input auxiliary equipment 10 such as various operation switches and sensors for outputting drive command signals for loads, and output auxiliary equipment 11 such as lamps and motors as loads driven by the input auxiliary equipment 10. is connected. Of these input auxiliary machines 10 and output auxiliary machines 11,
A brake lamp 12 as an output auxiliary machine 11 is connected to the controller 1a, and a brake switch 13 as an input auxiliary machine 10 is connected to the controller 1c.

FIG. 1 is a block diagram showing the detailed configuration of the controller 1c. The controller 1c includes a brake switch 13 and a turn signal switch 14 as input auxiliary equipment 10, and a wiper motor 15 as output auxiliary equipment 11.
A hazard lamp 16 and a panel lamp 17 are connected to each other. These auxiliary machines 10 and 11 are connected to a CPU 22 and a communication LSI 23 via an input/output interface 21. Further, this controller 1c is provided with a communication LSI 24 in addition to the communication LSI 23. The major difference between the communication LSI 23 and the communication LSI 24 is that the communication LSI 23 is an auxiliary device that is indispensable for maintaining safety and that must operate even when the controller is abnormal, such as a brake, among the auxiliary devices 10 and 11. The circuit is for transmitting and receiving data only to the switch 13, whereas the communication LSI 24 transmits and receives data to all normally operating auxiliary devices 10 and 11. Therefore, since the communication LSI 23 only needs to drive the minimum necessary auxiliary devices 10 and 11, no complicated control is performed, and the communication LSI 23 simply operates in a simple sequence such as serial-to-parallel conversion. On the other hand, the communication LSI 24 is driven under complex control such as message generation and analysis of communication history information, and is therefore controlled by software of the CPU 22.

A power supply circuit 25 is provided in the controller 1c. The power supply circuit 25 inputs a DC +12V power supply voltage supplied from the battery 5 via the ignition switch 4, and supplies, for example, a +5V power supply voltage to the input/output interface 21, the CPU 22, and the communication LSI 24. Further, +12V DC from the battery 5 is directly supplied to the input/output interface 21 and the communication LSI 23. Here, the input/output interface 21,
The CPU 22, the communication LSI 24, and the power supply circuit 25 constitute a first signal processing means. Further, the input interface 21, the communication LSI 23, and the power supply circuit 26 constitute a second signal processing means. As mentioned above, the second signal processing means accesses only a limited number of auxiliary devices, and is a simple operation system that does not include the CPU 22, and does not go through the power supply circuit 25, so that failure thereof is prevented. The probability of occurrence is much lower than that of the first signal processing means. The communication LSI 23 is connected to the transmission lines 6 and 7 via normally open contacts 27a and 27b. Furthermore, the communication LSI 24 is connected to the transmission lines 6 and 7 via normally closed contacts 28a and 28b. These contacts 27a, 27b, 28a, 2
8b is controlled to open and close by, for example, a relay 29 based on instructions from the CPU 22.

Next, the operation of the multiplex transmission apparatus according to the present embodiment configured as described above will be explained. In Figure 2,
The controller 1x has a function as a monitoring unit that monitors the other controllers 1a to 1d. For this reason,
The controller 1x performs a periodic calling operation to the other controllers 1a to 1d. Other controllers 1a-1
In response, d sends a message back. If there is no response, it is possible to detect in which controller the abnormality has occurred based on the identification code. Note that the function of such a monitoring unit may not be provided to a specific controller 1x, but may be provided to any one of the controllers 1a to 1x. Now, each controller 1a-1
When all of
Since the normally open contacts 27a and 27b are "open", the transmission line 6
, 7 are connected to the input/output terminals of the communication LSI 24. Also, at this time, the input/output interface 21 and the CPU 2
2 and the communication LSI 24 receive power from the power supply circuit 25 and are in an operating state. For this reason, the communication LS
Under the control of the CPU 22, the I24 performs normal multiplex communication of messages between controllers to control the connected output auxiliary equipment 11.

On the other hand, if the controller 1a fails,
Since the controller 1x detects an abnormality in the controller 1a through regular roll calls, it sends a switching signal to the controller 1c using its backup function. As a result, the CPU 22 inside the controller 1c controls the relay 2
9, the normally open contacts 27a and 27b are "closed".
, the normally closed contacts 28a and 28b become "open", and the transmission line 6,
7 is connected to the input/output terminal of the communication LSI 23. Also, at this time, the communication LSI 23 and the input/output interface 21 are in an operating state by receiving power directly from the battery 5, so one frame is transmitted from the communication LSI 23 by, for example, a synchronization signal, an address, data, etc. The configured messages are sent out at predetermined intervals according to an internal clock. Also, at this time, the controller 1a
detects that an abnormality has occurred in itself through the self-diagnosis function of the internal CPU 22, and connects the transmission lines 6 and 7 to the input/output terminals of the communication LSI 23 in the same manner as described above. As a result, communication by the second signal processing means is performed only between the controller 1a that cannot communicate and the controller 1c related thereto. Furthermore, message communication is performed by the first signal processing means as usual between the other controllers 1b and 1d.

[0013] The transmission lines 6 and 7 are connected to the communication LSI 23.
Since the communication LSI 24 and the communication LSI 24 are used for both, they may be provided separately, but in order to simplify the wiring harness, for example, as shown in FIG. , 7 should be shared. The start and end of time division are signals from the controller 1x as a monitoring unit in order to synchronize the timing of each controller 1a to 1d.
It is preferable to control by PU22. This time-sharing operation is performed only when one of the controllers becomes unable to communicate, and does not need to be performed when the system is normal. In addition, since the number of auxiliary devices handled by the communication LSI 23 is small,
The amount of data sent and received is also small. Therefore, the time delay when the normal controllers 1b, 1d turn on other lamps or transmit switch inputs is also small. Further, the communication LSIs 23 and 24 may be exactly the same, but if it is considered that they are used only for backing up auxiliary equipment related to safety, the objects to be controlled will be limited. Therefore, the communication LSI 23 is connected to the communication LSI 24.
It is desirable that the communication LSI 24 has higher reliability than the communication LSI 24, such as having fewer input/output terminals, a simpler protocol, and fewer gates.

[0014]

Effects of the Invention As described above, according to the present invention, the first
When the controller and the second controller to which the means for controlling the specific load is connected are normal, the first signal processing means communicates messages via the transmission path, When at least one of the first and second controllers becomes abnormal, the second signal processing means performs message communication via the transmission path, so even if the controller fails, the important auxiliary equipment remains operational. It is possible to prevent this from happening and greatly improve safety. Further, according to the present invention, the second signal processing means for backup operates only on the failed controller and other controllers related to it, so it does not affect the other controllers in any way. This also has the effect of eliminating the need for people to worry unnecessarily.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a controller in a multiplex transmission apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the overall configuration of the multiplex transmission device.

FIG. 3 is a timing diagram showing operations when a failure occurs in the multiplex transmission device.

FIG. 4 is a schematic diagram for explaining a conventional multiplex transmission device.

[Explanation of symbols]

1a to 1x, 31... Controller, 2, 6, 7... Transmission line, 4... Ignition switch, 5... Battery, 10,
33...Input auxiliary machine, 11, 32...Output auxiliary machine, 27a, 27
b...Normally open contact, 28a, 28b...Normally closed contact, 29...Relay.

Claims (1)

[Claims] 1. A plurality of controllers distributed in a vehicle, an auxiliary machine comprising loads connected to these controllers and means for generating a drive command signal for the loads, and a transmission path connecting the controllers. and a vehicle-mounted multiplex transmission device that performs drive control of the load via the controller by multiplexing messages between the controllers via the transmission path, wherein a first A second controller to which a controller and a means for generating a drive command signal for the load are connected is a first signal processing means for performing normal communication between these controllers, and a second controller to which a means for generating a drive command signal for the particular load is connected. a backup second signal processing means for performing communication for controlling only the controller; and a second signal processing means for connecting the first signal processing means and the transmission path when the first and second controllers are normal; The in-vehicle device is characterized in that it is equipped with switching means for connecting the second signal processing means and the transmission path when at least one of the first and second controllers becomes abnormal. multiplex transmission equipment.