JP2985521B2 - Automotive data recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording apparatus for an automobile, and more particularly to an apparatus for recording driving data when an abnormality occurs in an automobile.

[0002]

2. Description of the Related Art Conventionally, as a vehicle data recording apparatus of this kind, a so-called electronic system diagnostic tester is mounted on a vehicle and connected to, for example, a control unit for controlling an engine, and is set to an automatic recording mode. In some cases, when the latest result of the control unit malfunction judgment is abnormal or when the engine stalls, the driving data before and after the abnormality is automatically recorded (see "Nissan Consult Electronic System Diagnostics" issued by Nissan Motor Co., Ltd.). Tester Instruction Manual Engine ”, page 27). As a result, the cause of the failure can be estimated with high probability from the data recorded at the time of the failure.

The conventional example will be described in more detail. In such a system, an arithmetic processing unit (CPU) of an engine control unit always detects an accelerator opening, a throttle opening, and the like, and uses it for control.
Record data in M. In this case, for example, 20
An area for recording data for seconds is secured, and data is overwritten and recorded every 20 seconds.

When the engine speed becomes, for example, 20 rpm or less, it is determined that the engine is stuck, and data is recorded until 10 seconds elapse after the engine stall, and then data in a predetermined area in the RAM is moved to a predetermined area in the EEPROM. As a result, the data for 10 seconds before the engine stall detection and the data for 10 seconds after the engine stall detection are E
It is recorded and held in the EPROM.

[0005] In response to a request from the electronic system diagnostic tester, the data before and after the recorded engine stall can be transmitted using the communication function. In this example, the case of the engine stall has been described. However, it is apparent that the engine stall can be similarly recorded and held even when a failure occurs.

[0006]

However, in such a conventional data recording apparatus for a motor vehicle, the data can be recorded when the engine stalls or when a failure is detected. In the case where an accident occurs by accidentally stepping on the accelerator pedal, it is not a failure, so no data is recorded, and the cause cannot be determined at the time of the accident.

Further, in order to detect an accident, a method of using a judgment part of an airbag which has already been commercialized may be considered. However, this method cannot detect a minor accident and the cost required for the accident is high. There was a problem. The present invention
In view of such conventional problems, it is an object of the present invention to provide an inexpensive data recording apparatus for a vehicle which can record data with a high probability even in the case of a driving error.

[0008]

SUMMARY OF THE INVENTION Therefore, the present invention relates to a data recording apparatus for a vehicle, as shown in FIG. 1, for controlling the vehicle speed, engine speed, turning on / off an ignition switch, and wearing a seat belt. In addition to the means for detecting the presence or absence of the accelerator pedal or the presence or absence of the accelerator pedal, there is provided a means for recording driving data of the vehicle at the following timing (1) or (2) .

(1) When the vehicle speed is equal to or lower than a predetermined value (substantially 0), the engine speed is equal to or lower than the predetermined value (substantially 0), the ignition switch is turned on, and the seat belt is fastened. (2) When the vehicle speed is equal to or lower than a predetermined value, the engine speed is equal to or lower than a predetermined value, the ignition switch is turned on, and the accelerator pedal is depressed.

[0010]

According to the present invention, the vehicle speed, engine speed, ignition switch on / off, presence / absence of a seat belt, presence / absence of an accelerator pedal, etc.
And the driving data of the automobile is recorded at the timing of (1) or (2) .

If the vehicle is stopped normally , the above-mentioned condition (1) or (2) is unlikely to occur. Therefore, these conditions are detected, an accident is determined, and a trigger for data recording is made. Here, (1) corresponds to the ignition switch.
Not when the engine is stopped by the
Driver is detected by wearing belts), ignitions
Despite turning the switch ON,
It is assumed that the gin has stopped. In addition, seat belt
The presence / absence of the presence of the driver is detected by the presence / absence of a driver.
Usually wears a seat belt, as required by law
Because they do. Therefore, even if there is a driver,
Data cannot be recorded if the default is not installed.
However, the present invention is inexpensive without adding new devices
The aim is to detect accidents where possible in the configuration
So unavoidable. The above (2) is for ignitions
Ignition, not when the engine is stopped by the switch
If the driver operates the accelerator when the switch is turned on,
Nevertheless, assuming that the vehicle and engine stop
I have.

[0012]

An embodiment of the present invention will be described below. FIG. 2 shows a system diagram of the data recording device. Hereinafter, a data recording device for an engine control control unit including electronic throttle control will be described as an example.

The control unit 10 receives signals from various sensors and switches. Reference numeral 1 denotes an accelerator sensor, which outputs a voltage signal corresponding to the accelerator pedal depression amount (accelerator opening) ACC. Reference numeral 2 denotes a throttle sensor, which outputs a voltage signal corresponding to the opening TVO of the throttle valve.

Reference numeral 3 denotes a vehicle speed sensor, which outputs a pulse signal synchronized with the rotation of the output shaft of the transmission, and can detect the vehicle speed VSP based on the cycle of the pulse signal. Reference numeral 4 denotes a crank angle sensor which outputs a pulse signal at every predetermined crank angle,
The engine speed NE can be calculated from the cycle. 5
Is an ignition switch.

Reference numeral 6 denotes a seat belt switch, which is provided in the seat belt buckle portion and is turned ON when the seat belt is fastened, and OF when the seat belt is not fastened.
It becomes F. The control unit 10 includes a RAM 14 and an EEPROM 15 in addition to an input circuit 11, an arithmetic processing unit (CPU) 12, and an output circuit 13.

Here, the CPU 12 reads a signal from the sensor switch via the input circuit 11 according to a predetermined program, and performs arithmetic processing based on the signal.
Via an output circuit 13, an electronic control throttle (throttle actuator) 21, a fuel injection device 22, and an ignition device 23 are drive-controlled. On the other hand, the CPU 12 always detects the accelerator opening, the throttle opening, etc., and uses it for control.
Record data in AM14. In this case, an area for recording data for, for example, 20 seconds is secured in the RAM 14, and the data is overwritten and recorded in a cycle of 20 seconds. And
The data in RAM 14 is stored in EEPROM at appropriate timing.
Move to 15 and keep record. The EEPROM 15 has 20
An area for recording a plurality of seconds worth of data is secured.

The details of the recording operation will be described with reference to a flowchart. In the example of FIG. 3, if the vehicle is normally stopped, the vehicle speed VSP = 0, the engine speed NE = 0, the ignition switch is turned on, and the seat belt is fastened (the seat belt switch is turned on). Upon detection, it is determined that an accident has occurred, and this is used as a trigger for data recording.

The routine shown in FIG. 3 is executed, for example, every 10 msec. In step 1 (indicated as S1 in the figure, the same applies hereinafter), it is determined whether or not the vehicle speed VSP detected based on a signal from the vehicle speed sensor 3 is 0 (a predetermined value or less).
If VSP ≠ 0, proceed to step 2 and update the latest data such as accelerator opening ACC and throttle opening TVO to RA
The result is recorded in M14, and the process ends. In this case, the RAM 14
Has a recording area for 20 seconds of data.
The address counter is set at the start address of the recording area in a second cycle, the address counter is incremented each time recording is performed, and the address determined by the address counter is overwritten with the latest data and recorded. Thus, the latest 20 seconds of data when VSPＶ0 is always recorded in the RAM 14.

If VSP = 0, go to step 3.
In step 3, the engine speed NE detected based on the signal from the crank angle sensor 4 is 0 (not more than a predetermined value).
Is determined, and if NE か 0, the process ends.
If NE = 0, go to step 4. In step 4,
It is determined whether the ignition switch (IGNSW) 5 is ON. If the ignition switch 5 is OFF, the process is terminated.

In step 5, it is determined whether or not the seat belt switch (BELTSW) 6 is ON. If it is OFF, the process ends. If it is ON, it is determined that an accident has occurred and the process proceeds to step 6. In step 6, the data recorded in the RAM 14 is transferred to the EEPROM 15 for recording and holding, and the process is terminated. This part corresponds to data recording means. As a result, the data for 20 seconds before the accident judgment is EE
Recorded and held in the PROM 15. In this case, the EEPROM
15 has multiple areas for recording data for 20 seconds, and each time it is recorded, it is possible to record multiple data at the time of accident judgment by sequentially overwriting and recording different areas. It is.

After 10 seconds have passed since the accident was determined, the RAM 14
May be transferred to the EEPROM 15, and the data for 10 seconds before the accident determination and the data for 10 seconds after the accident determination may be recorded and held in the EEPROM 15. In the example of FIG. 4 which is another embodiment, if the vehicle is normally stopped, the vehicle speed VS
P = 0, engine speed NE = 0, ignition switch ON, accelerator pedal depressed (accelerator opening ≠ 0)
Since this state is unlikely to occur, this state is detected, it is determined that an accident has occurred, and this is used as a trigger for data recording.

Therefore, the routine shown in FIG. 4 differs from the routine of FIG. 3 only in the step 5 '. That is, under the conditions of the vehicle speed VSP = 0, the engine speed NE = 0, and the ignition switch ON, the process proceeds to step 5 ′,
It is determined whether or not accelerator opening degree ACC detected based on a signal from accelerator sensor 1 is equal to or smaller than ACC 所 定 0 (predetermined value or more; accelerator pedal depressed state). If ACC = 0, processing is terminated. If ACC ≠ 0, it is determined that an accident has occurred, and the routine proceeds to step 6, where the data recorded in the RAM 14 is transferred to the EEPROM 15 for recording and holding, and the process is terminated.

Incidentally, instead of using the accelerator sensor 1,
An accelerator switch that is turned on by depressing the accelerator pedal may be used as one of the accident detection conditions.

[0024]

As described above, according to the present invention, in order to detect an accident, a combination of vehicle speed, engine speed, on / off of an ignition switch, presence or absence of a seat belt , or vehicle speed, Engine speed, ignition
Switch on / off, accelerator pedal depression
By using a combination of the presence or absence of, by increasing the detection accuracy, and by enabling low-cost detection without using the accident determination function and the like used for airbags,
An inexpensive automobile data recording device can be realized.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a system diagram of a data recording apparatus showing one embodiment of the present invention.

FIG. 3 is a flowchart of the embodiment.

FIG. 4 is a flowchart showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Accelerator sensor 2 Throttle sensor 3 Vehicle speed sensor 4 Crank angle sensor 5 Ignition switch 6 Seat belt switch 10 Control unit 12 CPU 14 RAM 15 EEPROM

Claims (2)

(57) [Claims] 1. A vehicle speed, engine speed, the ignition switch on and off, chromatic of the seatbelt
Having a means for detecting the absence of the
If the engine speed is less than the specified value, the ignition switch
Is on and the seat belt is fastened.
A data recording device for a vehicle, comprising: means for recording driving data of the vehicle in a vehicle. 2. The vehicle speed, engine speed, ignition
Switch on / off, accelerator pedal depression
Means for detecting the presence or absence of
If the engine speed is lower than the specified value and the ignition switch
Switch is on and the accelerator pedal is depressed
There is a means to record vehicle driving data at the timing
A data recording apparatus for a vehicle, comprising: