JPH0478635A - On-vehicle apparatus control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to multiplex transmission in which data is sent and received by time division multiplex communication between a plurality of nodes via a common transmission path consisting of a pair of signal lines. The present invention relates to an in-vehicle equipment control device equipped with a system.

(Prior art) Conventionally, in order to prevent the number of signal lines from increasing due to the electronic control of automobiles, signals were sent and received between nodes installed in each part of the vehicle using a common multiplex transmission path. A vehicle multiplex transmission device (see Japanese Unexamined Patent Publication No. 1-36541) has already been invented.

When using the above-mentioned multiplex transmission system to operate a near conditioner (hereinafter simply referred to as air conditioner) unit as a control unit for in-vehicle equipment, for example, the air conditioner unit and the air conditioner are connected to a common transmission path consisting of a pair of signal lines. By connecting the switches independently, you can perform various air-conditioning and heating operations using only two signal lines in total.

However, if the air conditioner switch mentioned above breaks down, it will be difficult to send signals to the air conditioner unit.
There was also the problem that it was difficult to maintain comfort for the passengers.

Such problems also occur in a vehicle multiplex transmission system having control units and operation switches of other on-vehicle equipment as nodes.

(Purpose of the invention) This invention provides that even if a switch for operating in-vehicle equipment fails,
It is an object of the present invention to provide an on-vehicle equipment control device that can operate the above-mentioned on-vehicle equipment using an external signal.

(Structure of the Invention) The present invention is an in-vehicle equipment control device equipped with a multiplex transmission device that transmits and receives data by time division multiplex communication via a common transmission path consisting of a pair of signal lines between a plurality of nodes, It is equipped with a control unit for in-vehicle equipment, a switch for operating the in-vehicle equipment, and a car phone, and the control unit, the switch, and the car phone are each independently connected to the multiplex transmission device. Further, a signal sending means is provided for sending an external in-vehicle device activation signal obtained via the car telephone to the transmission path of the multiplex transmission device, and when the switch is in failure, the in-vehicle device activation signal from the outside is activated. The present invention is characterized in that it is an on-vehicle equipment control device configured to operate a control unit of the on-vehicle equipment via a signal sending means.

(Effects of the Invention) According to the present invention, when the switch for operating the above-mentioned in-vehicle equipment malfunctions, the on-vehicle equipment operating signal from the outside obtained via the car phone is transmitted through the above-mentioned signal sending means and the common transmission path. The information can be sent to the control unit of the on-vehicle equipment to activate the unit.

Therefore, for example, when an air conditioner unit is used as a control unit for on-vehicle equipment, it is possible to defrost the windshield to prevent it from fogging up, and to ensure comfort for the occupants.

Further, even when a control unit is used as a control unit of the above-mentioned in-vehicle equipment, there are various effects depending on the unit.

(Example) An embodiment of the present invention will be described in detail below based on the drawings.

The drawing shows an in-vehicle equipment control device using a multiplex transmission system. This multiplex transmission system is a bus-type distributed automotive LAN, and the right to use the transmission path is allocated only when there is a message to be sent to each node. Asynchronous time division multiplexing such as a contention method is used, and the access control method (multiplexing method) is a C8MA/CD method.

In FIG. 1, 1 is a balanced bus transmission line consisting of two signal lines 2 and 3, and the signal lines 2 and 3 are biased to a predetermined voltage level by bias resistor circuits R1 and R2, and R3 and R4, respectively. Ru.

A node 7 that operates as a fault diagnosis device is connected to the above-mentioned balanced bus transmission line 1 via lines 4 and 5 and a bus interface 6, and a node 11 that operates as an air conditioner switch is connected via a line 89 and a bus interface 10. - is connected to the line 12, 13, a notch 15 acting as a telephone adapter is connected via the bus interface 14, and also a line 16, 1.
．． 7. A node J9 that operates as an air conditioner unit is connected via the bus interface 18.

Here, each of the above-mentioned nodes 7.11, 15.19 is configured to access the transmission signal to the transmission line 1 via the respective bus interface 6.1014.18, and each of the nodes 7.11. Node addresses Nα7, Nα11, Nα15, and Nα19 are assigned to nodes 15 and 19, respectively.

The above-mentioned node 7 has a fault diagnosis function for the entire system, and the other nodes 11. ．． Unlike 15.19, it has a signal amplitude detection circuit 20 and operates as a fault diagnosis device.

Further, the above-mentioned air conditioner switch (node 11) is laid out on the steering pad.

FIG. 2 shows the configuration of the bus interface 6. The transmitting section is composed of a differential driver 21 that sends out transmission signals using the signal lines 2 and 3 of the transmission line 1.
Transmission is performed such that the polarity of the transmitted signal is reversed between signal lines 2 and 3.

That is, the differential driver 21 transmits a positive polarity PWM digital signal to one signal line 2 using a constant bias voltage determined by bias resistor circuits R1 and R2 as a reference, and transmits a positive polarity PWM digital signal to the other signal line 2. 3, a negative polarity signal obtained by inverting the above-mentioned PWM digital signal with a constant bias voltage determined by bias resistor circuits R3 and R4 as a reference is transmitted.

The receiving section includes an AC coupling circuit 22 that cuts the DC bias component of the received signal from the transmission line 1, a differential amplifier 23 that amplifies the output of the AC coupling circuit 22, and a threshold voltage that generates a predetermined threshold voltage. The output signals of the voltage generation circuit 24 and the differential amplifier 23 are set to the threshold voltage v of the threshold voltage generation circuit 24.
th and a comparator 26 for outputting an output signal to the communication IC 25.

This cosciparator 26 is configured to maintain the signal amplitude of the received signal received from the transmission line 1 by the differential amplifier 23, or even if the signal amplitude becomes smaller due to a failure etc. as will be described later, the signal amplitude is greater than a predetermined value v+h. This is re-converted to zero into a digital signal of a constant voltage level and sent to the CPU 27 side, thereby allowing the CPU 27 to read the received signal without error.

FIG. 3 shows a more detailed electric circuit configuration of the receiver (N part) of the bus interface 6, and this embodiment shows the capacitor C3.
This is a bus interface circuit for a balanced transmission system using an AC coupling circuit 22 based on C4, so that even if one bus signal of the signal lines 2.3 does not come in the event of an abnormality, data can be received using only the other bus signal. It is composed of

In FIG. 3, a resistor R1-1 and a capacitor C5, and a resistor R1, 2 and a capacitor C6 each constitute a filter that cuts high frequency components of the bus signal.

Diode D8 prevents the DC component from changing due to the duty ratio of the bus signal pulse, and also reduces the forward voltage VD.
F to set the differential reception sensitivity of the receiving circuit.

Diode D9 protects the input terminal of comparator 26 by absorbing positive and negative surges of the bus signal.

Resistors R13, R14, R15, R16 and resistor R18 set the differential reception sensitivity and hysteresis of the comparator 26.

The base voltage and emitter voltage of the transistor TR are always shifted by approximately the base-emitter voltage VBE,
Furthermore, since it is connected to the emitter follower circuit, the input impedance on the base side of the transistor TR is high and the signal transmission speed is sufficiently high.

Therefore, even if the transistor TR is inserted into only one transmission line of the balanced bus transmission line 1, neither the time balance of the received signal nor the impedance balance of the bus interface receiving circuit is lost.

The emitter follower circuit of the transistor TR also serves to prevent the inverting input terminal (-) of the comparator 26 from swinging to the negative side.

By inserting the transistor TR into the bus interface receiving circuit, the transistor TR will be turned off even if a negative voltage lower than the base-emitter voltage V BEO when the collector of the transistor TR is open is input to the base. This is to prevent the voltage at the inverting input terminal (-) of the comparator 26 from becoming lower than ground.

The diode DIO prevents the positive surge voltage entering from the base of the transistor TR from passing through to the collector and being applied to the power supply.

FIG. 4 shows the configuration of the signal amplitude detection circuit 20, including level shift circuits 28 and 29 that shift the bias voltage level of the signal lines 2 and 3 to a predetermined reference level, and the peak of the output signal of each level shift circuit 28 and 29. Peak hold circuits 30 and 31 that hold values, peak hold circuits 30 and 3
The output signals of 1 and 1 are A/'D converted and sent to the CPU.
27, and an inverter 33 for inverting the polarity of the received signal on the signal line 3 side. The configuration is such that the data is converted and input to the CPU 27.

FIG. 5 schematically shows the format structure of a transmission frame F sent and received on the network of a multiplex transmission system, and this transmission frame F has an SD (start delimiter).
code, ID (identification) code, own station address, data 1
The frame has a frame structure including data N, an error check code, and an ACK field.

Here, the SD code is a specific code indicating the start of the transmission frame F.

Further, the ID code specifies a functionally assigned address (function address), and in the embodiment shown in FIG. 1, the function address in the node 7 as a failure diagnosis device is set as shown in the following table, for example.

[From this table, for example, function address 4 is a node]
1 and node 19, and function address 5 is to be sent to node 1-1, node 15, and node 19.

Each node 11, 15, and 19 is equipped with a correspondence table of function addresses and physical addresses for transmission, as in the example of the failure diagnosis device (node 7) in the table above, and recognizes which physical node to send to. do.

Similarly, it has a reception function table and recognizes which function address frame should be received.

Further, the address of the node transmitting this frame F is written in the own address, and the node receiving this frame can know from which node the frame F was sent.

Further, the number of subsequent data is written in the data length, and in this case, if there are N pieces of data, N is sent as the data length. The node that receives this frame F reads data equal to the data length.

By recognizing the transmitted content or error check code (error detection signal) that follows the data, it is possible to know that the frame has come to an end.

In order to ensure data transmission, the receiving node uses a check code to check whether there are any errors in the content of the received frame, and if there are no errors, sends its own address to the transmission line as a reception confirmation frame (ACK frame). Send to 1.

Furthermore, in the CK field (reception confirmation signal), the AC
A K signal return area (time slot) is allocated, and normal reception is confirmed.

That is, the ACK field is sent to all nodes 7.11, 15, and 19° connected to the network.

This is a reception response signal return area, and this area is divided into a plurality of time slots (each one hit) as shown in FIG.
1, 15, 19, etc., respectively. Each node 7, 1.1. , i 5゜19..., when a transmission frame is normally received, the AC in the transmission frame is
A 1-bit acknowledgment ACK is returned to the source node of the transmission frame via transmission path 1 at the time slot position assigned to the local station in the K field.

A specific example is shown in FIG. 6. From node N1 to node N
Frame F is transmitted with il and node N19 as destinations, and node Nil and node N19, which have received the frame F, send out ACK signals in the areas corresponding to their respective nodes.

As mentioned above, in FIG. 1, the node addresses of nodes 11.1519 are Nα, 11, Nα15, Nα, 1, respectively.
9, and the node address of the failure diagnosis device (node 7) is set to Nα and 7, respectively. When the diagnostic function is started, the fault diagnostic device (node 7)
) is transmitted.

That is, since the ID code is "5", data D is sent to all nodes connected to the network.

Since the node that receives this data D is predetermined to immediately return an ACK frame, the node 11
．． 15.19 are shown in Figures 7(c), (e), and (d), respectively.
ACK frame F2. F4. Return F3.

At this time, the transmission path access method is the C8MA7CD method, and the order in which each node returns ], ], , 1915 is not particularly determined. Also, the reply ACK frame F2. F3. The contents of data E in F4 are also not particularly defined.

The fault diagnosis device (node 7) is connected to each node 11, 15.19
ACK frame F2. The signal amplitude of F4F3 is detected by the signal amplitude detection circuit 20, and based on this signal amplitude value, the occurrence of an abnormality in the transmission function of the source node is detected,
If an abnormality is detected, it is determined which node is faulty based on the local address of the abnormal ACK frame.

That is, FIG. 8 shows the signal waveform on signal line 2, and FIG. 9 shows the signal waveform on signal line 3.
In each figure, (a) shows the signal waveform when normal, and (b) and (C) show the signal waveform when the bus interface of the source node has failed.

The relationship between the signal amplitude value at the time of failure and the signal amplitude value at normal time is as follows.

Since the signal amplitude on each signal line 2 and 3 differs between normal and abnormal conditions, such as Vl>V2>V3 and V4>V5>V, this signal amplitude should be determined using a predetermined threshold value. Therefore, it is possible to immediately detect the occurrence of a failure in the signal function of the source node.

In addition, if the signal wires 2 and 3 are disconnected, have a ground fault to the ground, or have a short circuit to the power supply, it will no longer be possible to send or receive signals via the faulty signal wires, so even if such a fault occurs, Detect immediately.

In this way, for example, if the signal of the frame with the own station address Nα11 is small, it is diagnosed that there is an abnormality in the bus interface 0 of the node 11 serving as the air conditioner switch.

By the way, node 1 as the above-mentioned telephone adapter
5 is connected to a car telephone 35 via a special voice command analyzer 34, and this car telephone 35 is connected to a dealer's telephone 37 via a wireless telephone line 36. A signal generator 38 that sends an air conditioner operation pseudo-command signal as an external device operation signal is connected, and when a failure of the air conditioner switch (node 11) is automatically detected by the above-mentioned failure diagnosis device (node 7), the car telephone 35 is activated. The car telephone 35 is configured to automatically receive an air conditioner operation pseudo command signal from the signal generator 38 on the dealer side via the telephone 37 and wireless telephone line 36 on the same side in a transmitting/receiving state.

Here, the above-mentioned car telephone 35 sets the oscillation frequency of the vehicle as a mobile station to, for example, 915 to 925 M.
Hz, and the frequency of the base station is, for example, 860~
This is a so-called 800 MHz car telephone system with a frequency of 870 MHz.

Further, the above-mentioned special voice command analyzer 34 analyzes the special voice signal received by the car telephone 35 and converts it into a digital signal.

Furthermore, the above-mentioned telephone adapter (node 15) converts the above-mentioned digital signal into a multiplexed signal.

Furthermore, the above-mentioned signal generator 38 is connected to the car telephone 3.
Based on the call from 5, an air conditioner operation pseudo command signal (special voice command signal) is transmitted to the car telephone 35 of the vehicle court via each element 3736.

Now, when the above-mentioned fault diagnosis device (node 7) automatically detects a fault in the air conditioner switch (node 11), transmission line 1
The car telephone 35 is automatically set to a transmitting/receiving state via each element 14, 15, 34, and the car telephone 35 communicates the vehicle code and air conditioner operation to the dealer's telephone 37 via the wireless telephone line 36. A signal is sent to prompt the user.

On the dealer side, the above-mentioned coat and signal are received through the telephone 37, and the signal generator 38 is activated, and the air conditioner operation pseudo command signal from the signal generator 38 is sent to the vehicle via the telephone 37 and the wireless telephone line 36. Send the code to Car Telephone 35.

When the vehicle receives the above air conditioner operation pseudo command signal, the special voice command analyzer 34 converts the air conditioner operation pseudo command signal into a digital signal, and the telephone adapter (node 15) converts the above digital signal into a multiplexed signal. Then, an air conditioner activation multiplex signal is transmitted to the transmission line 1 via the bus interface 14 and line 1.2.13 to activate the air conditioner unit (node 19).

In this way, when the air conditioner switch (node 11) that operates the air conditioner malfunctions, the in-vehicle equipment operation signal (air conditioner operation pseudo command signal from the dealer side) obtained from the outside via the car telephone 35 is sent to the line 12.13.
and transmits it to the air conditioner unit via transmission line 1,
The unit (node 19) can be activated.

As a result, defrosting is possible if necessary, so
This has the effect of not only preventing the windshield from fogging up but also ensuring comfort for the occupants.

In the correspondence between the structure of the present invention and the embodiment described above, the pair of signal lines of the present invention corresponds to the signal lines 2 and 3 of the embodiment, and similarly, the common transmission line is a balanced bus transmission line. 1, the control unit of the on-board equipment corresponds to the node 19 that operates as an air conditioner unit, and the switch that operates the on-board equipment is:
Corresponding to node 11 that operates as an air conditioner switch,
The car telephone corresponds to the car telephone 35, the in-vehicle device activation signal from the outside corresponds to the air conditioner operation pseudo command signal transmitted from the dealer side, and the signal sending means corresponds to line 12.13. The invention is not limited to the configurations of the embodiments described above.

For example, a twisted pair wire may be used in place of the balanced bus transmission line 1 of the above-described embodiment, and the on-vehicle device may be an on-vehicle device other than an air conditioner, and the above-mentioned failure diagnosis device (node 7) may be used. Alternatively, the car telephone 35 may be directly operated by the driver.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention. Fig. 1 is a block diagram showing an in-vehicle equipment control device using a multiplex transmission system, Fig. 2 is a block diagram showing the configuration of a bus interface, and Fig. 3 is a reception diagram of the bus interface. FIG. 4 is a block diagram of the signal amplitude detection circuit, FIG. 5 is an explanatory diagram of frames sent and received through the transmission path, FIG. FIG. 7 is an explanatory diagram of frames transmitted and received on a transmission line, FIG. 8 is a waveform diagram showing the signal waveform on one signal line, and FIG. 9 is a waveform diagram showing the signal waveform on the other signal line. 1...Balanced bus transmission line 2.3...Signal line 1]...Node (air conditioner switch) 12, 1.3...
・Line 19...Node (air conditioner unit) 35...Car telephone

Claims (1)

[Claims] (1) An in-vehicle equipment control device equipped with a multiplex transmission device that transmits and receives data by time division multiplex communication via a common transmission line consisting of a pair of signal lines between multiple nodes, which includes an in-vehicle equipment control unit and , a switch for operating the in-vehicle equipment, and a car phone; the control unit, the switch, and the car phone as nodes are each independently connected to the multiplex transmission device; A signal sending means is provided for sending an in-vehicle equipment operating signal to the transmission path of the multiplex transmission device, and when the switch fails, the in-vehicle equipment operating signal from the outside is transmitted to the control unit of the in-vehicle equipment via the signal sending means. An in-vehicle equipment control device configured to operate.