JPS5929748A - Compensating method of trouble detection in instrumental system of driving parameter sensor for internal-combustion engine - Google Patents

Abstract

PURPOSE:To secure the driving of an engine ever so smooth even if there were anything unusual in the instrumental system of a parameter sensor earlier than the engine start, by making a prescribed value within the range of a normal output of the parameter sensor so as to be stored in a memory device. CONSTITUTION:Output signals out of various driving parameter sensors are fed to an A/D converter circuit 1 via an input unit comprising a level correction circuit, etc., and converted into a digital signal. The A/D converter 1 makes an A/D conversion end signal, namely, a reading pulse is produced there when the A/D conversion of a first parameter sensor's output signal is over, and causes the stored value of a new value register 3a to be renewed to a new parameter value. The new parameter value of the new value register 3a is fed to an abnormal value discrimination circuit 4 and discriminates on whether the output value of the new value register 3a is abnormal or not. The abnormal discrimination circuit 4 is impressed on a previous value register 8 and has the stored value of the previous value register 8 renewed to the new parameter value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting and compensating for an abnormality in the measurement system of an operating parameter sensor D of an internal combustion engine, and in particular, a method for detecting and compensating for an abnormality when the measurement system for an operating parameter sensor is abnormal before the engine starts. Regarding.

The various engine operating parameter values of the internal furnace engine are measured, such as engine rotation speed, absolute pressure in the intake pipe, throttle valve opening, exhaust oxygen concentration, engine temperature, and atmospheric pressure. (The above-mentioned engine operation is performed in an engine control system that determines engine control variables such as fuel supply amount, ignition timing, and exhaust gas recirculation amount according to parameter values)
(When the output value of the parameter sensor that measures the parameter value shows an abnormal value due to a disconnection, etc., if this abnormal value is used to determine various engine control amounts, the control amount will not be the appropriate value and will have a negative impact on driving performance, etc.) It is obvious that it falls short,
It is necessary to take measures to ensure engine operation even if the measurement system including the parameter sensor's wiring system, the input device for the output signal of the sensor, etc. breaks down.

Therefore, when the output value of the parameter sensor shows an abnormal value for a predetermined period of time, it is diagnosed that the if side system of the parameter sensor is abnormal, and when the output value of the parameter sensor shows an abnormal value, it is diagnosed that the IF side system is abnormal. There is a known method of determining fuel injection amount, etc. using the normal value of
-115101).

In this method, if the parameter sensor measurement system is abnormal before the ignition switch is turned on, the sensor measurement system becomes abnormal from the time the ignition switch is turned on, that is, from the time the parameter sensor measurement system abnormality detection starts. On the other hand, since the normal value is not yet stored in the storage means that stores the normal value immediately before the sensor indicates an abnormality, the abnormal parameter value is used to determine the engine control amount, and the engine operation is interrupted. There may be cases where this becomes impossible.

The present invention has been made to avoid such inconveniences, and includes a method for storing a predetermined value within the normal output value range of the parameter sensor in the storage means when the operation parameter sensor measurement system abnormality detection compensation device starts operating. To provide a method for detecting and compensating for an abnormality in a measurement system of an operating parameter sensor of an internal combustion engine, which allows at least engine operation to be ensured even if the measurement system of the parameter sensor is abnormal before the engine is started.

Examples of the method of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing an example of a parameter value abnormality detection and compensation device to which the method of the present invention is applied. The output signals of the various operating parameter sensors are supplied to the A/D conversion circuit 1 via an input device including a level correction circuit (not shown) and converted into digital signals, and the digital signals correspond to the number of operating parameter sensors. Multiple 4ND circuits 2a, 2
b, 2c... are supplied to t[ru]. AND circuit 2α,
21! l, 2c... are the current value registers 6α, 2. h, Z, c...
... are connected to each other. Note that in FIG. 1, only the current value register 3α corresponding to the first parameter sensor is shown for the sake of simplicity. Predetermined control signals C'Ho, C
H, , CH2, etc. are generated sequentially, for example, every time a predetermined rotation angle position signal of the engine is generated, in synchronization with this rotation angle position signal, and are connected to an AND circuit 2 corresponding to each parameter sensor. +26, 2c... is supplied.

Now, the control signal CHo corresponding to the first parameter sensor
is supplied to the AND circuit 2α, the AND circuit 2α
is in the open state, and the digital signal corresponding to the output value of the first parameter sensor from the A/D converter 1 is sent to the current value register 3 via the opened AND circuit 2α.
This time it is supplied to α as a parameter value. On the other hand, A/D
The converter 1 is an I/D converter for the output signal of the first parameter sensor.
When the conversion is completed, an A/D conversion end signal, that is, a read pulse is generated to update the stored value of the current value register 3α to the current parameter value. The current parameter value of the current value register 6α is supplied to the abnormal value determination circuit 4, which determines whether or not the output value of the first parameter sensor is abnormal.

Various methods can be considered for the abnormality determination method of this abnormal value determination circuit 4. For example, when a state in which the sensor output value is out of a predetermined range continues for a predetermined period of time, the measurement system including the parameter sensor is abnormal. It may be determined that there is.

When the abnormal value discriminating circuit 4 determines that the output value of the first parameter sensor is not abnormal, the abnormal value discriminating circuit 4 outputs a high level signal=1 from its output terminal 4a, and the high level signal is transmitted to the inverter described later. Together with the high level signal from 6, the 4ND circuit 5 is brought into an open state. The AND circuit 5 is supplied with the current [11J parameter value from the current time value register α, and the current time parameter value is in an open state. It is supplied to the previous value register 8 via the 4ND circuit 5 and the OR circuit 7. On the other hand, the abnormal value discriminating circuit 4 generates a data reading pulse at the output terminal 4b, applies the data reading pulse to the previous value register 8 via the OR circuit 9, and changes the stored value of the previous value register 8 to the current parameter value. Update to . The stored value updated in the previous value register 80 is
For example, it is supplied to an engine control device (not shown) such as a fuel supply amount control device and used to determine an engine control amount.

When the abnormal value discriminating circuit 4 determines that the output value of the first parameter sensor is abnormal, the abnormal value discriminating circuit 4 inverts the output value from the output terminal 4α to a low level=0, and sets the ANL( b) The output terminal 4 can be closed and omitted from the path 5.
Stop generating data read pulses from b. Therefore, the stored value in the previous value register 8 is no longer updated, and the stored value stored when the control signal was generated last time is continuously output.

Next, when the engine is started, for example, when the ignition switch 10 is closed and the parameter value abnormality detection compensation device is initialized, the first parameter value stored in the initial value memory 11 is within the normal output value range. A method for storing a predetermined value in the previous value register 8 will be explained.

First, when the ignition switch 10 is closed, the battery voltage is supplied to the voltage regulator 12.
A constant voltage of 10 Vcc is generated on the output side of KFi. In addition, FIG. 2 is a diagram illustrating how the signal voltages at connection points α to Da in the circuit of FIG. 1 change over time. Figure 2 shows the voltage change at the connection point 2 between the resistor R and the capacitor C of the integrating circuit connected to the output side of the voltage regulator #12 and consisting of the resistor R6, capacitor C8, and diode D1. As shown in the figure, the resistance value of the resistor R8 and the capacitor C are
It has a time iIi″L determined by the time constant of I. Connection point h
The inverter 16, which is in the K connection, remains in the K connection from when the ignition switch 10 is closed until the voltage at the connection point S reaches the threshold value v (from time t to t in FIG. 2). outputs a high level signal. A resistor R7 and a capacitor C'2 are connected in series between the output side of the inverter 13 and the ground, and a connection point d between the resistor R2 and the capacitor C7 is connected to one input terminal of the AND circuit 15. ,
The other input terminal of the AND circuit 15 is connected to the output side of the inverter 13 via the inverter 14.

When the output of the inverter 16 is inverted from a high level to a low level (threshold voltage v at point C in FIG. 2), the inverter 1
4 is inverted to a high level, and from the time of this inversion until the voltage at the connection point d reaches the threshold value υ (time t in Figure 2)
1 to t! 2), the AND circuit 15 outputs a high level signal (voltage level at point e in FIG. 2).

The OR circuit 16 includes the inverter 13 and the AND circuit 15.
When the output of one of the two is high level, i.e. the second
Time t shown in the figure. A high level signal is output for a period of t (voltage level at one point in FIG. 2). The high level signal from this OR circuit 16 is supplied to an AND circuit 17 to open the AND circuit 17, and the initial value memory 11
The predetermined value stored in is supplied to the input side of the previous value register 8 via the AND circuit 17 and the OR circuit 7, while the high level signal from the OR circuit 16 is converted to a low level by the inverter 6. This low level signal closes the AND circuit 5.

When the output of the AND circuit 15 is inverted from low level to high level (time '+' in FIG. 2), the capacitor c3. A differentiating circuit consisting of a resistor R9 and a diode D generates a single strobe pulse (point 1 in Figure 2), which is supplied as a read signal to the previous value register 8 via an OR circuit 9, which A predetermined value from the initial value memory 11 is stored at the timing of application of a read pulse.

The predetermined value stored in the previous value register 8 when the ignition switch 10 was closed as described above is determined by the abnormal value determination circuit 4 as the output value of the first parameter sensor is abnormal, as described above. Subsequently, the previous value is held in the previous value register 8 and used for determining the engine control amount.

However, if the output value of the first parameter sensor is not abnormal, the predetermined value stored in the previous value register 8 as described above is changed to the current parameter from the current value register 6a when the current control signal is generated. updated to the value.

Further, the second . The parameter value abnormality detection compensation circuits corresponding to each of the sixth parameter sensors can be explained in the same manner as described above, so the explanation will be omitted below.

As described in detail above, according to the measurement system abnormality detection and compensation method for an internal combustion engine operating parameter sensor of the present invention, when the operation parameter sensor measurement system abnormality detection and compensation device starts operating, the parameter sensor is within the normal output value range. Since a certain predetermined value is stored in the storage means, even if the measurement system of the parameter sensor is abnormal before the engine is started, at least the operation of the engine can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an output value abnormality detection and compensation device for an engine operating parameter sensor to which the method of the present invention is applied, and FIG. 2 is a timing chart illustrating signal voltage changes at connection points a to d of the circuit in FIG. It is. 3α...Current value register, 4...Abnormal value discrimination circuit,
5...AND circuit, 8...Previous value register, 10.
...Ignition switch, 11...First XJHa memory, 17...AND circuit. Procedural amendment (voluntary) November 27, 1980 Kazuo Wakasugi, Commissioner of the Japan Patent Office ■, Indication of the case 1982 Patent Application No. 139391 2 Title of the invention 8] Measurement system for internal combustion engine operating parameter sensor Abnormality Detection Compensation Method 3, Relationship with the Amendment Person Case Patent Applicant Address 6-27-8 Jingumae, Shibuya-ku, Tokyo Name (5
32) Honda Motor Co., Ltd. Representative Kawa
Yoshiyoshi Shima 4, Agent Address: 301 Sunshine Koken Plaza, 3-2-4 Higashiikebukuro, Toshima-ku, Tokyo 170 Telephone: 03 (983) 0926 Name: Patent Attorney (818g) Toshihiko Watanabe 5, Subject of amendment (1) Detailed explanation of the invention in the specification column) Drawing 6, contents of amendment (1) Detailed explanation of the invention in the specification column No. 5 of the description
Page, line 13, ``Generate J and send this read pulse to the current value register 3a via the A N I3 circuit 2a' whose one terminal is supplied with the control signal CI.
Correct "by giving to." (2) Figure 1 of the drawings shall be amended as shown in the attached sheet. −3(

Claims (1)

[Claims] 1 The output value of a parameter sensor that detects the operating parameter value of the internal combustion engine is read every time a predetermined control signal is generated, and the output value is stored in a storage means, and the parameter read when the predetermined control signal is generated this time. A measurement system for an operating parameter sensor that, when an abnormal output value of the sensor is detected, retains the stored value stored in the storage means when the previous signal was generated, and continuously outputs the stored value. The abnormality detection and compensation method is characterized in that a predetermined value within a normal output value range of the parameter sensor is stored in the storage means when the operation parameter sensor measurement system abnormality detection and compensation device starts operating. A measurement system abnormality detection compensation method for internal combustion engine operating parameter sensors.