JP2925546B2 - Vehicle decentering detection device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle center-off detection device for detecting the center-off of a plurality of warning lamps.

(Prior Art) In recent years, electronics have been advanced in automobiles, a large number of electrical components have been mounted, and wire harnesses have been enlarged due to the connection, resulting in problems such as an increase in weight and deterioration in the attachment of wiring and the like. I have.

Therefore, as described in, for example, Japanese Patent Application Laid-Open No. 62-4658, a multiplex communication system for multiplexing and transmitting given information has been proposed.

More specifically, for example, each multiplex node includes a plurality of multiplex nodes connected in a network configuration on a common multiplex transmission path, and transmits data for each frame having a destination address from any of the multiplex nodes. When the multiplex node specified by the address has received normally, a reception confirmation signal is returned from the specified multiplex node following this frame.
In the distributed control type multiplex transmission system using the CSMA / CD transmission system, as shown in a schematic configuration in FIG. 4, a plurality of multiplex nodes, for example, via a multiplex transmission line (bus) MB composed of a twisted pair or the like, The front multiplex node FN, the combination switch multiplex node CS, the meter multiplex node MT, and the rear multiplex node RN are connected. Note that the front multiple node FN
, A front turn left signal lamp 21, a front turn left signal lamp 22, a front small lamp 23, and a horn 24 are connected, and the combination switch multiplex node CS has a turn light switch 25,
Turn left switch 26, small lamp switch 27,
Horn switch 28, headlamp high beam switch 29
A turn light indicator 30, a turn left indicator 31, and a headlamp high beam indicator 32 are connected to the meter multiplex node MT, and a rear turn light signal lamp 33, a rear turn A left signal lamp 34 and a tail lamp 35 (the tail lamp 35 is turned on when the small lamp switch 27 is turned on) are connected.

In FIG. 5, which shows an example of the system configuration of the multiplex node of the automobile and the electrical components, a front multiplex node FN, a combination switch multiplex node CS, a meter multiplex node MT, a left cowl multiplex node LC, and a rear multiplex node are shown.
The RN is arranged at the position shown in the figure, the turn right switch 25 and the turn left switch 26 are connected to the combination switch multiplex node CS, and the wiper motor 36 and the air conditioner blower 37 are connected to the left cowl multiplex node LC.

In such a multiplex transmission system for vehicles, vehicle driving information is transmitted for each frame F having a configuration as shown in FIG. 6 (a). Here, this frame F is SD
(Start Delimiter) code, priority code,
The frame has a frame ID code, a data length, data 1 to data N, and a check code.

First, the SD code is a specific code indicating the start of the frame F, and the receiving multiplex node recognizes the start of the frame F when receiving the SD code code. The priority code is a code indicating a priority that supports which signal should be processed with priority when a plurality of multiplex nodes transmit data at the same time and signals collide.
When a collision of a plurality of data occurs, data having a higher priority is processed first. The frame ID code is a code for identifying what data is assigned to each bit in the data area, that is, a code indicating a combination of data in the data area of the frame F. The receiving multiplex node can know the data content of the data area of the frame F from the frame ID code.

The number of following data is written in the data length,
In this case, if there are N data, N is sent as the data length. The multiplex node that has received this frame reads only the data of the data length. Then, the transmission content following the data is a check code (error detection code), and by confirming this, it is possible to know that the end of the frame has been reached. For the purpose of ensuring data transmission, the receiving multiplex node checks whether there is any error in the content of the received frame using the check code, and if there is no error, T2 as shown in FIG. 6 (b).
After a certain time T1 within the time, the own station address is transmitted to the multiplex transmission path MB as a reception confirmation signal (ACK signal) A.
The multiplex node that has transmitted the frame F receives the acknowledgment signal A, and recognizes that the data has been normally received on the receiving side.

When the receiving side does not receive data correctly (when an error is detected by the check code) or when a framing error occurs (when the data actually sent is shorter or longer than the length specified by the data length) Has the seventh
The ACK signal is not returned from the receiving side as shown in FIG. In this case, as shown in FIG. 7 (a), if the ACK signal is not returned within the fixed time T2 after the frame transmission is completed, the transmitting side determines that the transmission of the frame F has failed, and retransmits the same frame F. Start sending.

As described above, the receiving multiplex node determines the frame ID code, and if the data is necessary for its own multiplex node, fetches this data and returns a reception confirmation signal. If it is, no acknowledgment signal is returned. The transmitting multiplex node has information as to which multiplex node the data of the frame ID code is required, and knows from which multiplex node the acknowledgment signal should be sent. If the reception acknowledgment signal is returned from the predetermined multiplex node, the transmission ends, but if the reception acknowledgment signal is not returned, the transmission multiplex node performs retransmission.

By the way, conventionally, the detection of the disconnection of the warning lamp
All the warning lamps are turned on when the ignition switch is ON and the alternator is not generating power before the engine is started, so that the driver can perform the operation visually.

(Problems to be Solved by the Invention) In addition, when the multiplex communication system as described above is employed to detect not only the vehicle but also the disconnection of the warning lamp, there is a demand to use a CPU to electrically detect the disconnection. There is.

The present invention has been made in view of such a point, and an object of the present invention is to provide a vehicle decentering detection device that can electrically detect whether each warning lamp is decentered or not.

(Means for Solving the Problems) In order to achieve the above object, according to the invention of claim (1), a plurality of changeover switch means respectively connected to a plurality of warning lamps and connected to the ground side of the lamps are provided. ,
Failure detection means provided in correspondence with each of the warning lamps, for detecting a predetermined failure state, and the changeover switch means for turning on the corresponding warning lamp when a failure is detected by the failure detection means ON
A plurality of switches having a control means for operating and a diode having one end connected between each of the warning lamps and the changeover switch means corresponding to the lamp, and allowing a current to flow from the one end toward the other end; A lead detection line, a common line to which the other ends of the plurality of disconnection detection lines are connected, and one of the plurality of changeover switch means being turned off and the other changeover switch means being turned on. And a disconnection detecting means for detecting a warning lamp in a disconnected state based on the voltage of the common line in that state.

In the invention of claim (2), the disconnection detecting means is configured to be activated when each warning lamp is turned on to check the disconnection.

In the invention according to claim (3), the disconnection detecting means is configured to sequentially perform the OFF operation of only one changeover switch means for each of the plurality of changeover switch means.

(Operation) In the invention of claim (1), when a failure state is detected by the failure detection means, the changeover switch means corresponding to the failure detection means is turned ON by the control means, and a warning lamp indicating the failure state is turned on. Is done.

When the centering of the warning lamp is detected by the centering detection unit, only one of the plurality of switching units is turned off and the remaining switching units are turned on. A warning lamp in an out-of-center state is detected based on the voltage. That is, one end of a disconnection detection line having a diode is connected between each warning lamp and the changeover switch means, and the other end of the disconnection detection line is connected to a common line. , The ground side is also connected to one common line via a diode. For this reason, when only one of the plurality of changeover switch means corresponding to the warning lamp is turned OFF, and if the warning lamp corresponding to the OFF changeover switch means is not disconnected, the battery voltage becomes lower than the warning lamp. Then, the voltage is applied to the common line via the disconnection detection line, and the voltage of the common line increases. Therefore, by detecting the voltage of the common line, it is possible to check the disconnection of the warning lamp that has been turned off.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1, L (1), L (2),..., L (n) are warning lamps, one end of which is connected to the Ig line 1 and the battery voltage is detected. , And the other end is grounded via transistors Tr (1), Tr (2),..., Tr (n) as changeover switch means. That is, the transistors Tr (1), Tr (2),
..., Tr (n) are warning lamps L (1), L, respectively.
(2),..., L (n), corresponding to the lamps L (1), L
(2),..., L (n) are connected to the ground side.

Each of the transistors Tr (1), Tr (2),..., Tr (n)
Means that the collector is a warning lamp L (1), L
(2),..., L (n), and the emitter is grounded. Further, each transistor Tr (1), Tr (2),.
The base of Tr (n) is connected to signal ports P (1), P (2),..., P (n) of CPU3 as control means, and the signal ports P (1), P ( 2),..., P (n), the drive signal is transmitted from each transistor Tr (1), Tr (2),.
By inputting to the base of (n), the transistor Tr
(1), Tr (2),..., Tr (n) are turned ON, and warning lamps L (1), L (2),.
(N) is turned on.

Each of the above warning lamps L (1), L (2), ..., L
(N) and the transistors Tr (1), Tr (2),..., Tr (n) corresponding to the lamps L (1), L (2),. Has a centering detection line l (1),
One end of (2),..., L (n) is connected, and the other end of each of the plurality of disconnection detection lines l (1), (2),. It is connected.

In addition, each of the above-mentioned centering detection lines l (1), (2),.
(N) includes one end (each warning lamp L (1), L
(2),..., L (n) and transistor Tr (1), Tr
(2), Diodes D (1), D (2),..., D that allow only current in the direction from the connection to Tr (n) to the other end (common line 2). (N) are connected in series, and each warning lamp L (1), L (2),
.., L (n) are transistors Tr (1), Tr (2),.
In parallel with (n), diodes D (1), D (2),.
It is connected to one common line 2 via (n).

The common line 2 is grounded via the resistor 4 and is used to detect the voltage of the common line 2.
It is also connected to the detection port Po of CPU3.

Thus, the CPU 3 has
Only one of (1), Tr (2),..., Tr (n) (switching switch means) is turned off and the remaining transistor T
r (1), Tr (2),..., Tr (n) are turned ON, and the transistors Tr (1), Tr
(2), warning lamp L corresponding to Tr (n)
(1), L (2),..., L (n), the warning lamps L (1), L (2),. ) Also functions as a core disconnection detecting means.

Further, the CPU 3 is connected to a multiplex transmission bus line 6 via a multiplex interface 5.

The multiplex transmission bus line 6 has failure detection switches SW (1), SW (2),..., SW (n) corresponding to the warning lamps L (1), L (2),. Is connected to the warning signal generation node 7. With this, when a failure occurs, a failure detection switch corresponding to the failure
Since SW (1), SW (2),..., SW (n) are closed, the corresponding signal ports P (1), P (
From (2),..., P (n), the above-mentioned transistors Tr (1), Tr
(2),..., Tr (n) drive signals are output.

Reference numeral 8 denotes an off-board checker, which is connected to the multiplex transmission bus line 6 and outputs warning lamps L (1), L (2),..., L (n) from the CPU 3 via the multiplex interface 5.
Is output.

The CPU 3 is configured to operate when each of the warning lamps L (1), L (2),..., L (n) is turned on to check for core breakage. That is, as shown in FIG. 2, in the CPU 3, while the warning lamps L (1), L (2),... , T2,..., Tn, the warning lamps L (1), L (2),..., L (n) are turned off by turning off the transistors Tr (1), Tr (2),. By sequentially turning off the lights, the warning lamp L
(1), L (2),..., L (n) are detected.
Since the voltage on the common line 2 is not at the “High” level at the check timing of T1, T2,.
A determination is made as to whether or not the core has been broken. Next, the flow of a process for checking the centering of the warning lamp 1 in the above apparatus will be described with reference to FIG.

First, when started, it is determined whether or not an ignition switch (not shown) is turned on (step S).
1) If not ON, repeat this determination again.

When the ignition switch is turned on, the port number i of the signal port is set to i = 1 (step S2), and
The signal port P (i) of the port signal i at one of the signal ports P (1), P (2),..., P (n) of the CPU 6, that is, the warning lamp L (i )
Signal port P (i) corresponding to the transistor Tr (i)
From the other signal ports (signal ports other than P (i)) from the "Hi" level signal (step S3).
gh "level signal (step S4). Thereby, only one of the transistors Tr (1), Tr (2),..., Tr (n) is turned off, and the other transistors Tr (i) are turned off. The transistor is turned on.

Thereafter, the voltage V applied to the common line 2 through the signal port Po of the CPU 3 is detected (step S5), and it is determined whether the voltage V is at the “High” level (step S5).
6) If "High" level, warning lamp L
Since (i) is not disconnected, the port number i is immediately updated to i = i + 1 to move to the next signal port (step S7). On the other hand, if the port number is "Low", the warning lamp L (i) is turned off. Since the core is disconnected, “Lo”
The fact that the level is "w" is stored (step S8), and the process proceeds to step S7.

After the processing in step S7, the port signal i is equal to the total number of ports n
Is determined (step S9), and if it is larger, all the warning lamps L (1), L (2) by all the signal ports P (1), P (2),..., P (n). ,…, L
Since the decentering check in (n) has been completed, the process is terminated as it is. On the other hand, if it is not large, the process returns to step S3, and the same decentering check is performed for the remaining warning lamps.
That is, in the CPU 3, only one transistor Tr
(1), Tr (2),..., Tr (n) are sequentially turned off for each of the plurality of transistors Tr (1), Tr (2),.

Therefore, by sequentially changing the transistors Tr (1), Tr (2),..., Tr (n) to be turned off, all the warning lamps L (1), L (2),. , L
For (n), it is possible to carry out a check for core breakage. still,
From the driver's point of view, this is the same as turning on all warning lamps to check for a conventional disconnection.

(Effect of the Invention) As described above, according to the present invention, only one of the changeover switch means for controlling the lighting of the warning lamp in response to the detection of the failure state of the failure detection means is turned off, and the other is set to O.
N, and set the voltage on the earth side of the warning lamp to 1
Since it detects through the common line of the book and detects the disconnection of the warning lamp based on this voltage,
Only by detecting the voltage of the common line, it is possible to electrically determine whether or not each warning lamp is disconnected.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is an overall configuration diagram of a vehicle decentering detection device, FIG. 2 is a time chart of a decentering detection procedure, and FIG. 3 shows a processing flow. FIG. 4 is a flow chart, FIG. 4 is a schematic configuration diagram showing a multiplex transmission system for a vehicle using the CCSMA / CD transmission system, FIG. 5 is a schematic top view showing a system configuration example of a multiplex node of a vehicle and electric components, and FIG. And FIG. 7 are diagrams for explaining frames in the conventional multiplex transmission system for automobiles. L (1) to L (n) Warning lamp, Tr (1) to
Tr (n): transistor (switching means), D
(1) to D (n) ... diode, l (1) to l (n)
... Disconnection detection line, SW (1) to SW (n)... Failure detection switch (failure detection means), 2.... Common line, 3.
CPU (control means, disconnection detection means)

Continuation of front page (56) References JP-A-57-126739 (JP, A) JP-A-51-81325 (JP, A) JP-A-57-87094 (JP, A) JP-A-51-39836 (JP, A) (A) JP-A-59-174041 (JP, A) JP-A-51-115327 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60R 16/02 B60Q 11/00 H05B 37/03

Claims (3)

(57) [Claims] 1. A plurality of changeover switch means respectively connected to a plurality of warning lamps and connected to the ground side of the lamps, and a failure detection means provided corresponding to each of the warning lamps and detecting a predetermined failure state. Control means for turning on the changeover switch means so as to turn on the corresponding warning lamp when a failure is detected by the failure detection means; and one end corresponding to each of the warning lamps and the lamp. A plurality of disconnection detection lines that are connected between the changeover switch means and have a diode that allows current to flow in a direction from the one end to the other end; and the other end sides of the plurality of disconnection detection lines are connected. And turning off only one of the plurality of changeover switch means and turning on the other changeover switch means. Moni, vehicle sectional core detecting apparatus characterized by comprising in that state and a disconnection core detection means for detecting a warning lamp in the sectional core state based on the voltage of the common line. 2. The system according to claim 1, wherein the disconnection detecting means is configured to be activated when each warning lamp is turned on to check the disconnection.
Item 7. The vehicle center-loss detection device according to claim 1. 3. The system according to claim 1, wherein the disconnection detecting means is configured to sequentially perform an OFF operation of only one changeover switch means for each of the plurality of changeover switch means. 7.) The vehicle center-loss detecting device according to the item (1).