JP2785068B2 - Storage method for vehicle data - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to vehicle operation data relating to a control state of a vehicle, a traveling state of a vehicle, and an operation state of an air conditioner and other various vehicle equipment mounted on the vehicle. And the like for storing data.

(Prior Art) For example, digital data in a control unit such as an electronically controlled internal combustion engine and operation data of various vehicle devices are taken out, and data indicating the operating state of various vehicle equipment obtained from these data is calculated. There has been proposed a monitoring device which is processed and displayed by a display means so that the operating state of the vehicle equipment and the control state of the vehicle can be visually observed. In this type of device, each data is sequentially stored in a predetermined memory for each type, or data indicating the type of the data is attached to each data and stored in the predetermined memory in the order in which they are obtained. (See, for example, JP-A-59-81708).

(Problems to be Solved by the Invention) However, when data is stored as described above, there is no problem when all data is output and taken in at predetermined time intervals. Are different or the timing of occurrence is irregular, the following problems occur.

That is, when it is necessary to analyze the operating state of the internal combustion engine in association with, for example, the on / off state of the brake, the vehicle acceleration, or other vehicle driving states, even if the required data is read from the memory, the data may be read. The temporal relationship between the data is not accurate, and high-precision analysis cannot be performed. Also, to solve this problem,
A method of writing data every time a predetermined clock pulse is generated is conceivable. However, storing data by such a method causes another problem that memory use efficiency is reduced. .

It is an object of the present invention to provide an improved method of storing vehicle data, which can solve the above-mentioned problems in the prior art.

(Means for Solving the Problems) A feature of the method of the present invention for solving the above problems is that first data indicating vehicle control information output at an appropriate timing from a control unit for controlling the vehicle and first data. A second data indicative of the operating state of the vehicle, which is taken out at predetermined time intervals, and a vehicle data storing method for storing in a buffer memory, one of the first or second data. While sequentially storing data in one direction from a predetermined address of the buffer memory, sequentially storing the other of the first or second data in another direction from another address of the buffer memory, When the remaining area of the buffer memory becomes smaller than a predetermined value due to the storage of the two data, the address is initialized and used as a ring buffer. In this case, the address pointer information of the buffer memory at the time of storing the data is stored as synchronous data together with the second data at the time of storing the second data.

(Operation) In the ring buffer memory, first data is sequentially stored from a predetermined address in one direction, and at the same time, second data is sequentially stored from another address in a direction opposite to the one direction. It is memorized. At this time, the address point of one data is stored as synchronization information together with the other data when the other data is stored. Therefore, when analyzing the data read from the ring buffer memory, the temporal relationship between the first and second data can be easily known.

Further, even when the first data amount and the second data amount differ depending on the system used, the buffer memory can be used effectively only by the difference between the sizes of the two ring buffers.

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

FIG. 1 is a block diagram showing an embodiment of a vehicle monitoring system configured to store vehicle data according to the method of the present invention. The control unit 3 includes an internal combustion engine 2 and a digital computer. The control unit 3 controls the operation of the internal combustion engine 2 electronically.

In order to monitor the operation control state of the electronically controlled internal combustion engine device 1 by means of digital data in the control unit 3, the desired digital data in the control unit 3 is provided with an identification code for identifying the type of the data in a known manner. Is converted into serial data with the transmission line 5
, And sent to the monitoring unit 4 separate from the internal combustion engine device 1. The serial data is formed according to a predetermined data format. After being converted into parallel data by the monitoring unit 4, the serial data is stored in a predetermined area in a data storage memory based on the identification code. A microcomputer is provided in the monitoring unit 4 as described later, and control of data reading and processing of the read data are executed by the computer. The data indicating the operating state of the internal combustion engine 2 is directly input to the monitoring unit 4 without going through the control unit 3 as described later.

The monitoring unit 4 has display members 6 ₁ , 6 such as liquid crystal panels for displaying values indicated by respective data described later in physical quantities.
₂ ..., 6 _n are provided, and the contents of data obtained as a result of processing are displayed. Monitoring unit 4 further performs fault indication by the failure indicator lamp group 7 on the basis of the data indicating a fault condition, the respective data is converted into an analog signal by a D / A converter, the output terminal 8 ₁ to 8 _n It is configured to be able to output.

FIG. 2 is a block diagram showing the above-described monitoring system. From a serial data output port 10 of a central processing unit (CPU) 9 of a digital computer provided in the control unit 3, a plurality of types of data are output as bit-serial data according to a predetermined data format. These multiple types of data are
This is control information data Dx for controlling the internal combustion engine, which is output at an appropriate timing as a result of calculation by the CPU 9. In the illustrated embodiment, information such as the rotation speed and the fuel injection timing from the internal combustion engine 9 is input to the CPU 9 in the control unit 3 and the information is output to the transmission line 5 as control information data Dx and monitored. It is transmitted to the unit 4 side.

On the monitoring unit 4 side, an input circuit 11 for taking in serial data input through the transmission line 5 is provided, and the input circuit 11 converts the serial data into parallel data. In order to sequentially store the contents of the input data Dx, the monitoring unit 4 has a ring buffer memory 23.
Is provided.

The monitoring unit 4 further includes brake information from the brake switch 31, handle operation angle information from the handle 32, air conditioner refrigerant pressure information from the air conditioner refrigerant pressure sensor 33, engine coolant temperature information from the engine coolant temperature sensor 34, and the like. The operation information data Dy is input from an input port (not shown) as operation information data Dy, and is input to the ring buffer memory 23 via the input interface 24 and the bus line 13.

When the serial-parallel conversion of the input data Dx is completed,
An interrupt is sent from the input circuit 11 to the central processing unit (CPU) 12, and the parallel data is temporarily sent to the CP via the bus line 13.
The data is taken into U12, the type of the data is determined, and the data Dx is stored in a predetermined area in the RAM 14 according to the determination result. In the above description, the operation from the transmission of one piece of data to the storage of the data has been described. However, the desired data is sequentially stored in the RAM 14 by real-time processing by an interrupt operation based on the same procedure.

As described above, each digital data stored in the RAM 14 in the real-time processing is converted into a value of a corresponding physical quantity by referring to a predetermined scaling factor in the ROM 19 by the CPU 12, and binary data is converted into decimal data. The data is transferred to the display interface circuit 20. Data is further transferred from the display unit interface circuit 20 to the display device 21,
On the display device 21, the value of the physical quantity indicated by each data, for example, the value of the rotation speed, the cooling water temperature, the injection timing, etc. is directly displayed in a predetermined physical quantity unit.

Further, the converted data is sent to the data latch circuit 15 and latched, and the digital / analog converter (D / A) 1
The data is converted into analog data by 6 and is extracted via an analog switch circuit 17. The output side of the analog switch circuit 17, the sample-hold circuits ₁₈₁ to 18 _n of the number corresponding to the type of data is provided by the switching control signal S from the CPU 12, analog data from the digital analog converter 16 Is input to a predetermined sample-and-hold circuit according to the type of the data. Therefore, the same type of data is always input to the same sample-and-hold circuit, the output terminal 8 ₁ to 8 _n, analog data for each data appears as a voltage signal.

The output terminal 8 ₁ to 8 _n, connected observed indicator 25 via the switching unit 26, by the operation of the switching unit 26 performs a desired one of the waveform observation data in real time, or to connect a data recorder As a result, a temporal change of data can be recorded. If a device such as a multi-pen type pen recorder is used as the observation display 25, the switch 26 becomes unnecessary.

The contents of the digital data stored in RAM 14 are
A scaling factor for converting each digital data into a corresponding physical quantity value is stored in the ROM 19 for direct display as a physical quantity value indicated by the data. Here, the scaling factor is for correcting and normalizing the values of the rotation speed, the injection timing, and the like taken into the monitoring unit 4, and is set in advance according to the type of these various data. And stored in the ROM 19.

As described above, in the above-described monitoring system, the engine information such as the engine rotation speed and the fuel injection timing of the internal combustion engine 2 is sampled and held for each information, and the observation display 25 observes each information based on the sampled value. on the other hand, to record desired data by a data recorder connected to the output terminal 8 ₁ to 8 _n, these makes it possible to check the operating state and the operating state of the engine.

Reference numeral 27 denotes an abnormality determining means for detecting, when various kinds of data input from the input circuit 11 have caused any abnormality in the vehicle, an abnormality detection signal is output from the abnormality determining means 27. Switch or diagnostic switch 29
Is turned on, the accumulation of data in the ring buffer memory 23 is prohibited by the prohibition means 28.

FIG. 3 schematically shows the ring buffer memory 23 in an expanded manner. Ring buffer memory 23 has n addresses from the start address A ₁ to the last address A _n, and control information data Dx is a vehicle control information output at an appropriate time, every predetermined fixed time Is stored in the ring buffer memory 23 as follows.

That is, the data Dx is irregularly set as the control information data Dx.
Each time ₁ , Dx ₂ , Dx ₃ , ... are obtained, these data are
Together are stored in real-time processing in the RAM14 as described above, it is sequentially stored from the head address A ₁ toward the forward direction F.

On the other hand, as driving information data Dy, data Dy
Each time ₁ , Dy ₂ ,... Are obtained, these data are sequentially stored from the last address _{An in the} reverse direction R in the order of occurrence. In this case, the address pointer (for example, A ₄ ) at which the data Dx is currently stored is stored as P ₁ together with the data of Dy ₁ . That is, the latest address pointer data of Dx at the time of storing the driving information data Dy is stored at a required address together with the data to be stored at that time. In the example shown in FIG. 3, for example, when Dy ₂ is stored, DXa
There will be Aa enters the pointer information P ₂ if the latest data.

In the above-described memory write control, an address pointer is provided in the RAM 14, the address pointer is used to manage up to which address the writing has been completed, and when new data is input, the data is written to the next address, and between the two buffers. When the remaining area becomes equal to or less than a predetermined value, the address pointed to by the address pointer is initialized and A ₁
Or input data from the A _n address can be carried out as written. As a result, the newest data is written after the oldest data is erased, and even if the generation of the control information data Dx is irregular, for each of the data Dx and Dy, the past number corresponding to the number of storage addresses is obtained. Are best stored and retained.

In the above configuration, in order to perform an experiment, measurement, maintenance, inspection, or the like of a vehicle on which the control unit 3 is mounted,
When the serial data output port 10 and the input circuit 11 of the monitoring unit 4 are connected via the transmission line 5, the CPU 9
At the same time as sending the control information data Dx relating to the control of the internal combustion engine 2 to the monitoring unit 4, the brake information from the brake switch 31, the handle operation angle information from the handle angle sensor 32, the air conditioner refrigerant pressure information from the air conditioner refrigerant pressure sensor 33, Operating information data Dy such as engine cooling water temperature information from the engine cooling water temperature sensor 34 and engine information of the internal combustion engine 2 (rotational speed, fuel injection timing information, etc.) are separately transmitted to the monitoring unit 4 at predetermined time intervals.

The serial data input to the monitoring unit 4 is an input circuit
11 converts it into parallel data. When the serial-parallel conversion of the input data is completed, the input circuit 11 interrupts the CPU 12, and the parallel data is temporarily transmitted via the bus line 13.
The data is taken into the CPU 12, the type of the data is determined, and the data is stored in a predetermined area in the RAM 14 according to the determination result.

As for the data in the RAM 14, the normalized data is sent to the display interface circuit 20 and the data latch circuit 15, and at the same time, the first and second ring buffer memories 23, 24
Is written to the required address as described with reference to FIG.

If the abnormality determination unit 27 detects any abnormality during the above operation, the determination unit 27 inputs an abnormality detection signal to the prohibition unit 28. Then, the prohibition means 28 outputs a prohibition signal for prohibiting the accumulation of data in the ring buffer memory 23 after a lapse of a certain time or after the data accumulation amount reaches a certain amount, and prohibits the accumulation of data in the ring buffer memory 23. I do. Alternatively, when the operator performing the inspection work detects any abnormality and turns on the diagnostic switch 29, the prohibiting means 28 outputs a prohibition signal for prohibiting the accumulation of data in the ring buffer memory 23, and The accumulation of data in the buffer memory 23 is prohibited.

Then, the ring buffer memory 23 holds a predetermined amount of data collected before the occurrence of the abnormality detection signal or before the diagnostic switch 29 is turned on. Then, by transferring the held data to the display unit interface circuit 20 and the data latch circuit 15, it is possible to examine a change over time, and it is possible to easily analyze the cause of the abnormality.

In this case, the data D is stored in the ring buffer memory 23.
y ₁ , Dy ₂ ,... are irregularly output data Dx ₁ , Dx ₂ ,
.. Are stored together, it is possible to easily know the generation timing of each data taken out from the ring buffer memory 23. Therefore, when the control data and the data indicating the running state of the vehicle are simultaneously displayed in accordance with the time change, the timing of the two can be compared with high accuracy, and the control data of the internal combustion engine 2 and the operation of the vehicle can be compared. Analysis can be performed in association with the state data, and the operating state of the entire vehicle can be analyzed easily and with high accuracy. In addition, by using the ring buffer memory from both ends, required data can be stored extremely efficiently and to the maximum.

(Effects of the Invention) According to the method of the present invention, various vehicle data output at different timings can be efficiently stored using the ring buffer memory, and the ring buffer memory for one of the data can be stored. Since the pointer information is stored in the ring buffer memory when the other data is stored, synchronization between the data is achieved. Therefore, it is very easy to compare the data on the same time axis. An excellent effect is obtained such that analysis of vehicle data can be performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a vehicle monitoring system configured to store vehicle data according to the method of the present invention, FIG. 2 is a detailed block diagram of the system shown in FIG. 1,
FIG. 3 is a diagram schematically showing the ring buffer memory shown in FIG. 2 developed. 1 ... electronically controlled internal combustion engine device 2 ... internal combustion engine 3 ...
... Control unit, 4 ... Monitoring unit, 5 ... Transmission line, 9,12 ... Central processing unit, 23 ... Ring buffer memory, 31 ... Brake switch, 32 ... Handle angle sensor, 33 ... Air conditioner Refrigerant pressure sensor, 34 ... Cooling water temperature sensor, Dx ... Control information data, Dy ... Driving information data.

Claims (1)

(57) [Claims] 1. A first data indicating vehicle control information outputted at an appropriate timing from a control unit for controlling a vehicle, and a second data indicating an operation state of the vehicle extracted at predetermined time intervals. A method of storing vehicle data for storing data in a buffer memory, wherein one of the first or second data is sequentially stored in one direction from a predetermined address of the buffer memory, The other of the first or second data is sequentially stored in the other direction from another address in the buffer memory, and the remaining area of the buffer memory becomes smaller than a predetermined value due to the storage of the two data. In this case, the address is initialized and used as a ring buffer, and the address pointer information of the buffer memory at the time of storing the first data is stored. Wherein when storing the serial second data second
A method for storing vehicle data, wherein the data is stored as synchronous data together with the data.