JP2005059809A - On-vehicle system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle system capable of securely starting communication according to a communication system based on a polling system. <P>SOLUTION: An immobilizer ECU 2 on a master side and a steering lock ECU 3 and a power supply ECU 4 on a sleeve side are connected to a bus 1, and performs the communication according to the communication system based on the polling system. When the steering lock ECU 3 and the power supply ECU 4 transmit wakeup signals to the immobilizer ECU 2, they monitor signals outputted to the bus 1 for a specified time. When the wakeup signals are not outputted to the bus 1, they output the wakeup signals to the bus 1 to transmit to the immobilizer ECU 2. By this, the steering lock ECU 3 and the power supply ECU 4 do not simultaneously transmit the wakeup signals and the communication can be securely started. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an in-vehicle system that operates various devices mounted on a vehicle in an integrated and cooperative manner.

  2. Description of the Related Art Conventionally, a plurality of in-vehicle systems that connect various devices mounted on a vehicle via a LAN and operate them in an integrated and cooperative manner are known. In these in-vehicle systems, synchronous communication represented by CAN and BEAN is often used for communication between the various devices described above. However, since the communication protocol for synchronous communication is complicated, the structure of hardware and software for communication control is also complicated, and it takes a lot of time and effort to design it.

  Under these circumstances, in recent years, asynchronous communication is being used for communication between the various devices described above. Among them, especially the communication method based on the polling method can simplify the communication control hardware and software because the communication protocol is simple. Therefore, it is rapidly spreading as an in-vehicle LAN communication method.

  When a communication method based on the polling method is used as the communication method for the in-vehicle LAN, the various devices described above are divided into a single master device and a plurality of slave devices. When the master device receives the wake-up signal transmitted from one of the slave devices, the master device sequentially transmits polling signals to each slave device and starts communication with each slave device. To do.

  However, a wake-up signal may be simultaneously transmitted from a plurality of slave devices to the master device, for example, when the vehicle is activated. In such a case, a plurality of transmitted wakeup signals collide, and the master side device cannot receive the wakeup signal. As a result, the master device cannot communicate with each slave device.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an in-vehicle system capable of reliably starting communication according to a communication method based on a polling method.

  In order to achieve the above object, the in-vehicle system according to claim 1 is an in-vehicle system comprising a single master electronic device and a plurality of slave electronic devices, wherein the master electronic device is a plurality of slave electronic devices. When the operation start signal transmitted from any of the above is received, the operation is started and an inquiry signal is sequentially transmitted to each of the plurality of slave devices. Each of the plurality of slave electronic devices is sent to the master electronic device. An operation start signal is transmitted to start the operation, and when an inquiry signal transmitted from the master electronic device is received, communication is performed with a communication method based on a polling method in which various data are transmitted to and received from the master electronic device. An operation start signal from each other slave electronic device to the master electronic device is transmitted to each of the plurality of slave electronic devices. Detection means for detecting transmission is provided, and when each of the plurality of slave electronic devices transmits an operation start signal to the master electronic device, the detection means provided in the slave electronic device transmits the master electronic signal from another slave electronic device. It is determined whether or not transmission of an operation start signal to the apparatus has been detected, and when it is determined that this has been detected, transmission of the operation start signal is interrupted.

  As described above, the in-vehicle system of the present invention includes a single master electronic device and a plurality of slave electronic devices, and communication between the master electronic device and each slave electronic device is performed by a communication method based on a polling method. To be configured. Furthermore, each slave electronic device is provided with detection means for detecting transmission of an operation start signal from another slave electronic device to the master electronic device. When each slave electronic device transmits an operation start signal to the master electronic device, has the detection means provided in the slave electronic device detected transmission of an operation start signal from another slave electronic device to the master electronic device? Determine whether or not. And when it determines with having detected this, transmission of an operation start signal is interrupted. Accordingly, when any one of the plurality of slave electronic devices transmits the operation start signal, the other slave electronic devices interrupt transmission of the operation start signal. Therefore, the operation start signals are not transmitted simultaneously from the plurality of slave electronic devices, and the collision of the plurality of operation start signals can be avoided. Accordingly, the in-vehicle system can reliably start communication between the master electronic device and each slave electronic device.

  The master electronic device and each of the plurality of slave electronic devices are connected to a single bus and configured to communicate via the bus, and the plurality of slave electronic devices It is preferable that the detection means provided in each of the first and second detection units detect the operation start signal transmitted from the other slave electronic device by detecting the operation start signal output to the bus. By detecting the operation start signal output to the bus by connecting the master electronic device and each of the plurality of slave electronic devices to a single bus, the detection means provided in each slave electronic device Transmission of the operation start signal from the slave electronic device can be reliably detected.

  According to a third aspect of the present invention, each of the plurality of slave electronic devices receives an inquiry signal from the master electronic device even after a predetermined time elapses after transmission of the operation start signal to the master electronic device is interrupted. If this is not possible, it is desirable to try again to send an operation start signal to the master electronic device. Thereby, even when a communication error or the like occurs, the in-vehicle system can start communication between the master electronic device and each slave electronic device.

  As described in claim 4, each of the plurality of slave electronic devices can not receive the inquiry signal from the master electronic device even if it tries to transmit the operation start signal to the master electronic device a predetermined number of times. It is desirable to stop sending the operation start signal to the master electronic device. If the inquiry signal from the master electronic device cannot be received even after a predetermined number of attempts to transmit the operation start signal, a failure such as disconnection may have occurred. In such a case, it is preferable to stop the transmission of the operation start signal to the master electronic device to suppress excessive power consumption.

  As described in claim 5, the detection means provided in each of the plurality of slave electronic devices performs a detection operation for a set time, and the set time is different for each slave electronic device. Is desirable. As a result, when the detection operation of each slave electronic device is completed, the detection operation of other slave electronic devices is not simultaneously ended, and the wake-up signal is not simultaneously output from a plurality of slave electronic devices. Can do.

  FIG. 1 is a block diagram showing the overall configuration of an in-vehicle system according to an embodiment of the present invention. In the in-vehicle system of this embodiment, an immobilizer ECU 2 that is a master electronic device, and a steering lock ECU 3 and a power supply ECU 4 that are slave electronic devices are connected to a bus 1. Communication between the immobilizer ECU 2, the steering lock ECU 3, and the power supply ECU 4 is performed according to an asynchronous communication method based on a polling method.

  As shown in FIG. 1, the immobilizer ECU 2 is connected to a vehicle key cylinder (not shown), and authenticates an ID code transmitted from an electronic chip incorporated in the vehicle key. When the authentication result of the ID code is OK, a start permission signal is transmitted to the engine ECU 21 to permit start of an engine (not shown).

  When the immobilizer ECU 2 receives the wake-up signal (operation start signal) transmitted from the steering lock ECU 3 and the power supply ECU 4, the immobilizer ECU 2 sequentially transmits a polling signal (inquiry signal) to the steering lock ECU 3 and the power supply ECU 4. At this time, when a request signal for requesting an ID code authentication result is transmitted from the steering lock ECU 3 and the power supply ECU 4 as a response to the polling signal, the ID code authentication result is transmitted.

  The steering lock device 31 is composed of, for example, a mechanical stopper, and locks the vehicle steering 32 when a lock signal is acquired from the steering lock ECU 3. Further, when an unlock signal is acquired from the steering lock ECU 3, the steering 32 is unlocked. For steering locking, an electromagnetic stopper or the like may be used.

  When the steering lock ECU 3 receives a polling signal from the immobilizer ECU 2 in a state where the steering wheel 32 is locked, the steering lock ECU 3 transmits a request signal for requesting an ID code authentication result to the immobilizer ECU 2 as a response. Thereafter, when the authentication result of the ID code transmitted from the immobilizer ECU 2 is OK, a lock release signal is transmitted to the steering lock device 31. The steering lock ECU 3 transmits a lock signal to the steering lock device 31 when a vehicle key (not shown) is set to OFF.

  In particular, in the present embodiment, the steering lock ECU 3 is connected to a key cylinder of a vehicle (not shown). When the key of the vehicle is set to an ignition, an internal counter is activated and a signal output to the bus 1 is monitored. To start. Thereafter, when a wakeup signal is not output to the bus 1 for a predetermined time, the wakeup signal is output to the bus 1 and transmitted to the immobilizer ECU 2.

  The battery 41 is, for example, a vehicle battery, and stores electric power to be supplied to the immobilizer ECU 2, the steering lock ECU 3, the power supply ECU 4, and various devices 42 mounted on the vehicle. Note that the ECUs 2, 3, 4, and 21 described above are directly connected to the battery 41, and are always energized regardless of the open / closed state of a relay 43 described later.

  The relay 43 is, for example, an electromagnetic relay, and performs a switching operation as to whether or not the power output from the battery 41 is transmitted to various devices 42. Of course, a contactless relay using a semiconductor may be used.

  When the power supply ECU 4 receives a polling signal from the immobilizer ECU 2 in a state where the relay 43 is opened, the power supply ECU 4 transmits a request signal for requesting an ID code authentication result to the immobilizer ECU 2 as a response. Thereafter, when the authentication result of the ID code transmitted from the immobilizer ECU 2 is OK, the relay 43 is closed and power supply to the various devices 42 is started. Further, when a vehicle key (not shown) is set to OFF, the power supply ECU 4 opens the relay 43 and ends the supply of power to the various devices 42.

  In particular, in the present embodiment, the power supply ECU 4 is connected to a key cylinder of a vehicle (not shown). When the vehicle key is set to ignition, the internal ECU is activated and the signal output to the bus 1 is monitored. Start. Thereafter, when a wakeup signal is not output to the bus 1 for a predetermined time, the wakeup signal is output to the bus 1 and transmitted to the immobilizer ECU 2. The time for monitoring the signal output to the bus 1 by the power supply ECU 4 is set to be different from the time for monitoring the signal output to the bus 1 when the steering ECU 3 transmits the wake-up signal.

  The termination resistors 51 and 52 include, for example, series resistors, are attached to the termination of the bus 1 and suppress reflection of signals generated at the termination of the bus 1. The termination resistor may be configured by combining a regulator and a series resistor.

  Next, a process in which the steering lock ECU 3 transmits a wake-up signal will be described.

  FIG. 2 is a flowchart relating to a process in which the steering lock ECU 3 transmits a wake-up signal in the in-vehicle system of the present embodiment. The processing of this flowchart starts when the vehicle key is set to the ignition.

  In step 201, the steering lock ECU 3 starts an internal counter. In step 202, the signal output to the bus 1 is detected. By detecting the signal output to the bus 1, the transmission of the wake-up signal from the power supply ECU 4 can be reliably detected.

  In step 203, it is determined in step 202 whether or not a wake-up signal is detected on the bus 1. If a wake-up signal is detected, the process proceeds to step 207. Otherwise, go to step 204.

  In step 204, the internal counter value is incremented by one. In step 205, it is determined whether or not the value of the internal counter is equal to a predetermined value K. If it is determined that the value of the internal counter is equal to the predetermined value K, the process proceeds to step 206. If not, the process returns to step 202 and the above process is repeated.

  In step 206, a wake-up signal is output to the bus 1 and transmitted to the immobilizer ECU 2. On the other hand, in step 207, transmission of the wakeup signal is interrupted.

  The process in which the power supply ECU 4 transmits the wake-up signal may be set to a value other than K in step 205 of this flowchart, and the processes other than step 205 are exactly the same as those in this flowchart. become. By setting the value of the internal counter to a value other than K, the monitoring time of the bus 1 performed by the steering lock ECU 3 and the power supply ECU 4 is different, and at the same time the steering lock ECU 3 ends the monitoring operation, This prevents the ECU 4 from ending the monitoring operation and prevents the wake-up signal from being simultaneously output to the bus 1.

  Next, a process in which the steering lock ECU 3 transmits the wakeup signal again will be described.

  FIG. 3 is a flowchart regarding the process in which the steering lock ECU 3 transmits the wake-up signal again in the in-vehicle system of the present embodiment. The processing of this flowchart is started immediately after the steering lock ECU 3 transmits a wake-up signal.

  In step 301, the steering lock ECU 3 starts an internal counter. In step 302, it is determined whether or not a polling signal from the immobilizer ECU 2 has been received. If the polling signal can be received, the process ends. If not received, the process proceeds to step 303.

  In step 303, the internal counter value is incremented by one. In step 304, it is determined whether or not the value of the internal counter is equal to a predetermined value N. When it is determined that the value of the internal counter is equal to the predetermined value N, the process proceeds to step 305 and the wakeup signal transmission process is performed again. The wakeup signal transmission process is performed by executing the process of the flowchart of FIG. If the value of the internal counter is not equal to the predetermined value N, the process returns to step 302 and the above processing is repeated. Thus, even when a communication error or the like occurs, the communication can be reliably started by performing the wakeup signal transmission process again.

  Note that the process in which the power supply ECU 4 transmits the wake-up signal again is the same as the process in this flowchart, and thus the description thereof is omitted.

  Thus, in the in-vehicle system of the present embodiment, the immobilizer ECU 2, the steering lock ECU 3 and the power supply ECU 4 are connected to the bus 1 and configured to perform communication by a communication method based on the polling method. When the steering lock ECU 3 and the power supply ECU 4 transmit a wakeup signal to the immobilizer ECU 2, the signals output to the bus 1 are monitored for a predetermined time. If no wakeup signal is output to the bus 1, the wakeup signal is output to the bus 1 and transmitted to the immobilizer ECU 2. On the other hand, when a wakeup signal is output to the bus 1, transmission of the wakeup signal is interrupted. This prevents the steering lock ECU 3 and the power supply ECU 4 from simultaneously outputting a wakeup signal to the bus 1. Therefore, this in-vehicle system can reliably start communication with the immobilizer ECU 2, the steering lock ECU 3, and the power supply ECU 4.

  In the in-vehicle system of this embodiment, after the steering lock ECU 3 and the power supply ECU 4 transmit the wakeup signal, when the polling signal cannot be received even after a predetermined time has elapsed, an attempt is made to retransmit the wakeup signal. However, the number of attempts to retransmit the wakeup signal may be limited. If the polling signal cannot be received even after a predetermined number of attempts to transmit the wakeup signal, there is a possibility that a failure such as disconnection has occurred. In such a case, it is preferable to stop the re-transmission of the wake-up signal and suppress excessive power consumption.

  In the in-vehicle system of the present embodiment, the immobilizer ECU 2 is the master electronic device, but the steering lock ECU 3 and the power supply ECU 4 may be the master electronic device. Of course, a dedicated ECU may be prepared as the master electronic device.

  Furthermore, in the in-vehicle system of the present embodiment, each ECU is connected to a normal bus. However, each ECU may be connected by a wireless LAN. In this case, the steering lock ECU 3 and the power supply ECU 4 detect the transmission of the wakeup signal by detecting the radio wave received from the receiving antenna and determining whether or not this includes the wakeup signal.

  Finally, in the in-vehicle system of the present embodiment, any communication method based on the polling method can be suitably used without any distinction between synchronous and asynchronous.

1 is a block diagram illustrating an overall configuration of an in-vehicle system according to an embodiment of the present invention. In the vehicle-mounted system of this embodiment, it is a flowchart regarding the process in which a steering lock ECU transmits a wake-up signal. In the vehicle-mounted system of this embodiment, it is a flowchart regarding the process in which a steering lock ECU transmits a wake-up signal again.

Explanation of symbols

1 ... Bus 2 ... Immobilizer ECU
21 ... Engine ECU
3. Steering lock ECU
31 ... Steering lock device 32 ... Steering 4 ... Power supply ECU
41 ... Battery 42 ... Various equipment 43 ... Relay 51, 52 ... Termination resistance

Claims (5)

An in-vehicle system comprising a single master electronic device and a plurality of slave electronic devices,
The master electronic device starts operation upon receiving an operation start signal transmitted from any of the plurality of slave electronic devices, and sequentially transmits an inquiry signal to each of the plurality of slave devices, Each of the plurality of slave electronic devices transmits an operation start signal to the master electronic device to start operation, and receives an inquiry signal transmitted from the master electronic device. It is configured to communicate using a communication method based on a polling method that sends and receives various data.
Each of the plurality of slave electronic devices is provided with detection means for detecting transmission of an operation start signal from another slave electronic device to the master electronic device,
When each of the plurality of slave electronic devices transmits an operation start signal to the master electronic device, the detection means provided in the slave electronic device starts operation from another slave electronic device to the master electronic device. An in-vehicle system characterized by determining whether or not signal transmission has been detected, and interrupting transmission of an operation start signal when it is determined that this has been detected. The master electronic device and each of the plurality of slave electronic devices are connected to a single bus and configured to communicate via the bus,
The detection means provided in each of the plurality of slave electronic devices detects transmission of an operation start signal from another slave electronic device by detecting an operation start signal output to the bus. The in-vehicle system according to claim 1. When each of the plurality of slave electronic devices is unable to receive an inquiry signal from the master electronic device even after a predetermined time has elapsed after interrupting transmission of the operation start signal to the master electronic device, 3. The in-vehicle system according to claim 1, wherein transmission of an operation start signal to the master electronic device is attempted again. If each of the plurality of slave electronic devices fails to receive an inquiry signal from the master electronic device even after trying to transmit an operation start signal to the master electronic device a predetermined number of times, The in-vehicle system according to claim 1 or 3, wherein the transmission of the operation start signal is stopped. 2. The detection means provided in each of the plurality of slave electronic devices performs a detection operation for a set time, and the set time differs for each slave electronic device. Or the vehicle-mounted system of Claim 2.

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