JPH08270494A - Engine stop time data monitoring diagnostic method - Google Patents

Abstract

PURPOSE: To easily specify the cause of an engine stalling by taking out data at the optional time from a storage medium that can hold the input-output data of an engine control device, at the stop time of an engine. CONSTITUTION: A storage medium 6 that can hold and read input data inputted to a CPU 3b and processed output data is connected to an engine control device 3. An engine stalling time data monitoring diagnostic system applies the trigger every specified period and reads the present rotating speed, and judges whether an engine is being rotated at present or not (engine stalling). At the time of judging the engine to be in the rotating state, the engine stalling time data monitoring diagnostic system reads the present input-output data. An interruption is generated again and the engine speed is read, and when the engine is judged to be in a non-rotating state, the flow is ended without reading the input-output data. Data is thus recorded and updated every specified period, so that the storage medium 6 of small capacity can be used to construct the engine stalling time data monitoring diagnostic system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of diagnosing a data monitor when an engine is stopped.

[0002]

2. Description of the Related Art Conventionally, an engine is stopped in an automobile (hereinafter,
When the engine stall occurs, it is necessary to investigate various sensors, actuators, and control devices mounted on the automobile in order to discover the cause, which takes a lot of time and effort.

[0003]

In the above prior art, when the cause of the engine stalling is not clear, there is a risk that even parts that do not need to be replaced may be replaced.

An object of the present invention is to easily identify the cause of engine stall by performing data monitor diagnosis during engine stall and recording the state of the engine at engine stall.

[0005]

The above object can be solved by recording data of various sensors and actuators at the time of engine stall in a readable storage medium.

[0006]

By the above means, the data monitor diagnosis at the time of engine stall can be performed, and the cause of engine stall can be easily identified.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the present invention. 1 is an engine, 2 is input data such as the number of revolutions output from the engine, water temperature, battery voltage, exhaust temperature,
Input data group other than engine such as vehicle speed and switch, 3 is an engine control device for inputting and processing data, and controlling the engine to operate in an optimum state. 4 is an actuator control device based on the processing of the engine control device. Output data group 5 for control is a storage medium for holding input data input to the engine control device and output data for controlling the engine.

FIG. 2 is a processing block diagram of the engine control unit. 4a is an input processing circuit for input processing the input data group, and 4b is input data processed by the input processing circuit.
CPU that calculates to optimally control the engine, 4c is C
It is a drive circuit that drives various actuators and the like based on a signal output from the PU 4b.

The engine control unit 4 takes in the input data 2 from the engine and other sensors and removes noise and the like mixed in the input data by the input circuit 4a. The data processed by the input processing circuit is input to the CPU 4b, where arithmetic processing is performed so that the engine operates in an optimum state, and a signal for controlling each actuator is output. This signal is input to a drive circuit for driving each actuator, and data is output to the engine and each actuator. The storage medium 6 is a CPU
4b, which can hold and read the input data input to the CPU 4b and the output data that has been arithmetically processed.

FIG. 3 shows, as an example of the data monitoring method at the time of engine stall, a chart of each input / output data at the time of engine stall and a flow chart showing the contents of the data monitoring method at the time of engine stall. 31 is a chart showing the timing of data storage, 32 is a chart showing fluctuations in the number of revolutions, 33 is C
A chart showing fluctuations in water temperature, which is an example of data held by the PU 4b, and 34 is a chart showing fluctuations in vehicle speed, which is an example of data held by the CPU 4b.

This monitoring method is a method of recording and updating data by applying a trigger every predetermined period T. Hereinafter, description will be given according to the flowchart. The program shown in this flowchart is started every predetermined period T (for example, 10 ms). First, in S1, the current rotational speed N is read and the process proceeds to S2. In S2, it is determined whether the engine is currently rotating or not rotating (engine stall). If it is determined in S2 that the engine is rotating, the flow advances to S3 to read the current input / output data Dn and end this flow. An interrupt occurs again, the engine speed is read in S1,
When it is determined in S2 that the engine is not rotating (engine stall), the input / output data is not read and this flow is ended. In this way, a data monitor diagnostic system at the time of engine stall can be constructed by using a storage medium having a small capacity by recording and updating data at predetermined intervals.

FIG. 4 shows, as another example of the data monitoring method at the time of engine stall, a chart of each input / output data at the time of engine stall and a flow chart showing the contents of the data monitoring method at the time of engine stall. 41 is a chart showing the timing of data storage, 42 is a chart showing fluctuations in the number of revolutions, 33
Is a chart showing fluctuations in water temperature, which is an example of data held by the CPU 4b, and 34 is a chart showing fluctuations in vehicle speed, which is an example of data held by the CPU 4b.

This monitoring method specifies the engine stall condition and stores the input / output data at that timing. Now, as an example of the engine stall condition, the engine stall determination is performed when the rotation fluctuation ΔN within a predetermined period t exceeds a certain value. Hereinafter, description will be given according to the flowchart.
The program shown in this flowchart is started every predetermined period t (for example, 10 ms). First, in F1, the current engine speed Ntn is read and the process proceeds to F2. At F2, the engine speed Nt (n
From the difference between (-1) and the current engine speed Ntn, the rotation fluctuation ΔN in the predetermined period t is calculated, and the process proceeds to F3. In F3, it is determined whether the rotation fluctuation ΔN is larger or smaller than the engine stall determination value K. When it is determined in F3 that the engine stop determination value K is smaller than the engine stop determination value K, this flow is ended as it is. When the interrupt is generated again and it is determined in F3 that the rotation fluctuation ΔN is larger than the engine stall determination value K, the process proceeds to F4, the input / output data Dn at this time is read, and this flow is ended.
That is, the rotation fluctuation ΔN is measured every predetermined time period t, and when the predetermined value is exceeded, it is determined that the engine is stalled, and the input / output data at that time is recorded, whereby the data immediately before the engine stalling can be held. Further, according to the present method, since data writing to the storage medium only needs to be performed once before the engine stall, a data monitor diagnostic system at the time of engine stall can be constructed using a small and inexpensive storage medium that cannot be repeatedly written. .

Further, although the storage medium is installed outside the engine control unit in this embodiment, the present system can be built in the engine control unit by downsizing the storage medium by the above-mentioned method.

As described above, the monitor diagnosis of the engine stall data can be performed, and the cause of the engine stall can be easily identified.

[0017]

According to the present invention, the data monitor diagnosis at the time of engine stalling becomes possible and the cause of engine stalling can be easily identified.

[Brief description of drawings]

FIG. 1 is a block diagram of a system.

FIG. 2 is a processing block diagram of an engine control device.

FIG. 3 is an explanatory diagram of a data monitoring method at the time of engine stall.

FIG. 4 is an explanatory diagram of a data monitoring method at the time of engine stall.

[Explanation of symbols]

1 ... Engine, 2 ... Input data group, 3 ... Engine control device, 3a ... Input processing circuit, 3b ... CPU, 3c ... Output processing circuit, 4 ... Output data group, 5 ... Storage medium, 31 ... Data storage timing chart, 32 ... Chart showing rotation fluctuation, 33 ... Chart showing fluctuation of water temperature, 34 ... Chart showing fluctuation of vehicle speed, 41 ... Data storage timing chart, 42 ... Chart showing fluctuation of rotation.

Claims (3)

[Claims] 1. A method of processing data from a plurality of sensors and performing optimum control of an engine based on the results, capable of retaining input data and output data of an engine control device when the engine is stopped. A method for diagnosing a data monitor when an engine is stopped, characterized in that the data can be retrieved at any time by a storage medium. 2. The data monitor diagnosis at engine stop for reducing the size of the storage medium for holding data by holding and updating input / output data of the engine control device at predetermined time intervals. Method. 3. The storage medium for holding the data according to claim 2, wherein the condition when the engine is stopped is recognized by the rotation fluctuation within a predetermined period, and the input / output data of the engine control device is held. Miniaturized data monitor diagnosis method when engine is stopped.