JPS627963B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel consumption measurement method and apparatus for measuring fuel consumption based on the amount of fuel injected from a fuel injection device that injects fuel into a vehicle engine.

Conventionally, as a device of this type, there is a device that measures fuel consumption based on injection pulses from a computer that drives the injector in an electronically controlled fuel injection device (EFI).

However, this device has a problem in that it is not possible to determine an accurate amount of fuel consumption because it does not add and correct the increased injection amount delivered from the cold start injector at the time of starting the engine.

The present invention has been developed in view of the above-mentioned problems, and it is possible to accurately estimate fuel consumption by adding and correcting the increased injection amount based on the starting temperature at engine startup to the fuel consumption amount due to the fuel injection amount from the fuel injection device. It is an object of the present invention to provide a fuel consumption measuring method that can determine the amount of fuel consumed, and a device that can appropriately implement the measuring method.

The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 is an overall configuration diagram showing one embodiment of the present invention, in which the fuel injection amount is measured using an on-vehicle microcomputer that executes digital calculation processing by software according to a predetermined control program. It is.

In FIG. 1, reference numeral 1 denotes a water temperature sensor as a temperature detector, which detects the engine cooling water temperature as the starting temperature and generates a water temperature signal.
A start switch 2 generates a start signal when the vehicle key is inserted into the start position of the vehicle key box. 3 is an EFI computer that calculates the amount of air based on the signal from the airflow meter (not shown), divides this by the engine speed to determine the amount of air per cycle, and determines the basic injection amount. is corrected by signals from each sensor (not shown), and sends an injection pulse signal that drives an injector (not shown) that performs fuel injection. Reference numeral 4 denotes a delay circuit which receives an injection pulse signal from the EFI computer 3 and generates a low level pulse signal for a delay time of the valve opening operation of the injector with respect to this injection pulse signal. 5 is an oscillation circuit that generates a reference pulse signal of about 256kHz using a crystal oscillator. Reference numeral 6 is an AND circuit that performs an AND operation on the injection pulse signal from the EFI computer 3, the pulse signal from the delay circuit 4, and the reference pulse signal from the oscillation circuit 5 to generate an output pulse signal. . Reference numeral 7 designates an integration counter, which has an 8-bit digital counter that counts the output pulse signals from the AND circuit 6, and when the maximum count of the counter is reached, the number of the counter is cleared and an integrated pulse signal is sent out. be. Reference numeral 8 denotes a frequency division counter, which includes an 8-bit digital counter for counting the number of accumulated pulse signals from the integration counter 8, and sends out a frequency divided pulse signal when the number of the counter reaches the maximum count number.

Reference numeral 9 denotes a single-chip microcomputer that executes software arithmetic processing according to a predetermined control program, and constitutes an arithmetic processing means.
At the same time, it is in operation by constantly receiving a stabilized voltage from a stabilized power supply circuit (not shown) that receives power from the on-board battery and generates a stabilized voltage of 5V. . and,
Through the operation of this microcomputer 9, it receives the water temperature signal from the water temperature sensor 1, the start signal from the start switch 2, and the frequency division pulse signal from the frequency division counter 8, executes the calculation process of the measurement program, and calculates the fuel consumption. In response to display signals for updating the display and various signals from various sensors (not shown), various control programs other than the measurement program are executed, and various control command signals are issued accordingly.

This microcomputer 9 has a read-only memory (Read Only Memory) that stores a control program including a measurement program in which calculation procedures are predetermined.
Memory (ROM), and a central processing unit (Central Processing Unit) that sequentially reads the control program of this ROM and executes the corresponding arithmetic processing.
CPU), which temporarily stores various data related to the arithmetic processing of this CPU, and
Memory that can be read by Rondam Access
Memory; RAM), a clock generation section that generates reference clock pulses for the various calculations mentioned above with the crystal oscillator 10, an A/D conversion section that converts analog signals into digital signals, and input/output of various signals. It is made of a one-chip large-scale integrated circuit (LSI), and the main part is an input/output (I/O) circuit for adjusting the input/output (I/O) circuit.

Reference numeral 11 is a display device that displays the fuel consumption amount, and when it receives a display signal from the microcomputer 9, it shows a value of 0.1.
It is provided with a digital counter that adds up a number corresponding to the number of liters (), a display section that digitally displays the amount of fuel consumption corresponding to the number of this counter, and a reset button 11a that resets the count of the counter.

Next, the operation of the above configuration will be explained with reference to the calculation flowcharts shown in FIGS. 2, 3, and 4. FIG. 2 is an interrupt calculation flowchart showing the calculation processing of the interrupt routine based on the divided pulse signal of the frequency division counter 8 by the control program, and FIG. 3 is a calculation flowchart showing the calculation processing of the start measurement program by the control program. FIG. 4 is a calculation flowchart showing the calculation processing of the normal measurement program by the control program.

First, the arithmetic processing of the microcomputer 9 will be explained. Since the microcomputer 9 is constantly supplied with power, it repeats the main routine calculation processing including the start measurement calculation routine, the normal measurement calculation routine, and various control calculation routines at a cycle of several tens of milliseconds.

In this repetitive operation, when the frequency division pulse signal from the frequency division counter 8 is applied to the interrupt (INT) terminal of the microcomputer 9, the operation processing of the main routine is temporarily interrupted and the interrupt routine shown in FIG. Arriving at the interrupt start step 101, the program proceeds to the frequency division flag set step 102 to set the frequency division flag, and advances to the return step 103 to complete the interrupt processing of the interrupt routine and resume the previously interrupted arithmetic processing of the main routine. resume.

When the start measurement calculation routine is reached in the calculation process of this main routine, the process proceeds to starter determination step 201 in FIG. At times, the determination becomes NO, but when the start signal is generated, the determination becomes YES, and the process proceeds to timer determination step 202. In this timer determination step 202, it is determined whether or not timer data B set up to that point is "0", and when timer data B is "0", one calculation process of the start measurement calculation routine is completed. However, when timer data B is not "0", the determination becomes NO, and the process advances to water temperature input step 203. In this water temperature input step 203, an analog water temperature signal from the water temperature sensor 1 is read, it is converted into a digital signal, and the process proceeds to a water temperature determination step 204. In this water temperature determination step 204, the water temperature input step 203
It is determined whether the input engine cooling water temperature T is 35℃ or less, and when the engine cooling water temperature T is higher than 35℃, the determination becomes NO and one calculation process of the start measurement calculation routine is completed. However, the judgment is made when the engine coolant temperature T is 35℃ or less.
If the answer is YES, the process proceeds to the first determination step 205. In this first determination step 205, it is determined whether or not the first flag is set, and if the first flag is not set, the determination is NO.
However, when the first flag is set, the determination becomes YES, and the process advances to the first flag release step 206. In this first flag clearing step 206, the first flag is cleared and the process advances to starter flag setting step 207. In this starter flag setting step 207, the starter flag is set, and the process advances to timer setting step 208. In this timer setting step 208, timer data A corresponding to the engine cooling water temperature T input in the water temperature input step 202 is obtained using a preset function f, and the process proceeds to a conversion step 209. In this conversion step 209, the timer data A set in the timer setting step 208 is converted into timer data B to be subtracted from the timer data A, and the timer data A is temporarily stored as it is, and the timer data A is changed to the timer data B to be subtracted.
Go to 0. Further, when the determination in the first determination step 205 is NO, the process also proceeds to the timer operation step 210. In this timer operation step 210, in order to keep the repetition cycle time of the main routine constant at 100 msec, the internal clock is used until the calculation time from the previous time to this time reaches 100 msec. The wait state is maintained, and when the time reaches 100 msec, the process advances to subtraction step 211. In the subtraction step 211, the constant "1" is subtracted from the timer data B (B=B-1) to update the timer data B, and the timer determination step 21
Proceed to step 2. In this timer determination step 212, it is determined whether or not timer data B is "0". When timer data B is "0", the determination is YES, but when timer data B is not "0", the determination is YES. becomes NO, and one calculation process of the start measurement calculation routine is completed.

On the other hand, the judgment in starter judgment step 201 is
If NO, or if the determination in timer determination step 212 is YES, the process advances to starter flag determination step 213. In this starter flag determination step 213, it is determined whether or not the starter flag is set. If the starter flag is not set, the determination becomes NO and one calculation process of the start measurement calculation routine is completed. The judgment is made when the flag is set.
YES, starter flag release step 21
Proceed to step 4. This starter flag release step 21
In step 4, the starter flag is canceled and the process proceeds to the first flag setting step 215. In this first flag setting step 215, the first flag is set, and the process proceeds to timer calculation step 216. In this timer calculation step 216, the timer setting step 2
The timer data B is subtracted from the timer data A set in step 08 to obtain the number of times data N, that is, the number of times the calculation of the main routine is repeated while injecting fuel from the cold start injector, and the increased injection amount is calculated. Proceed to step 217. In this increased injection amount calculation step 217, the number of times data N
is multiplied by the repetition period time t, that is, 100 msec, to obtain the fuel injection time from the cold start injector. The increased injection amount Fs is calculated by multiplying by a constant (Fs=N·t·K), and the process proceeds to addition step 218. In addition step 218, the increased injection amount Fs is added to the cumulative injection amount F (F=F+Fs) to update the cumulative injection amount F, and the process proceeds to cumulative injection amount determination step 219. In this cumulative injection amount determination step 219, the cumulative injection amount F
It is determined whether or not is 0.1 or more, and when the cumulative injection amount F is less than 0.1, the determination becomes NO,
One calculation process of the start measurement calculation routine is completed, but when the cumulative injection amount F is 0.1 or more, the process proceeds to display output step 220. In this display output step 220, a display signal for updating the fuel display on the display 11 by 0.1 is issued to the display 11, and the process proceeds to a cumulative injection amount update step 221. In this cumulative injection amount update step 221, a calculation is performed to update the cumulative injection amount F by subtracting 0.1 from the cumulative injection amount F, and one calculation process of the start measurement calculation routine is completed.

When the arithmetic processing of this start measurement arithmetic routine is completed, the next normal measurement arithmetic routine is reached, and the process advances to frequency division flag determination step 301 in FIG. In this frequency division flag determination step 301, it is determined whether or not the frequency division flag is set. When the frequency division flag is not set, the determination becomes NO, and one calculation process of the normal measurement calculation routine is completed. However, when the frequency division flag is set, the judgment becomes YES, and the frequency division flag release step 3 is performed.
Proceed to 02. This frequency division flag release step 302
Then, the frequency division flag is canceled and the process proceeds to integration step 303. In this integration step 303, the frequency divided pulse 1
The minute injection amount △F corresponding to the injection time is set in advance, and the minute injection amount △F is added to the cumulative injection amount F (F=
F+ΔF) to update the cumulative injection amount F, and proceed to cumulative injection amount determination step 304. In this cumulative injection amount determination step 304, it is determined whether the cumulative injection amount F is 0.1 or more, and when the cumulative injection amount F is less than 0.1, the determination becomes NO, and one calculation process of the normal measurement calculation routine is performed. However, when the cumulative injection amount F is 0.1 or more, the process proceeds to display output step 305. In this display output step 305, a display signal for updating the fuel display on the display 11 by 0.1 is issued to the display 11, and the process proceeds to a cumulative injection amount update step 306. In this cumulative injection amount update step 306, a calculation is performed to update the cumulative injection amount F by subtracting 0.1 from the cumulative injection amount F.
One calculation process of the normal measurement calculation routine is completed.

Next, the overall operation of measuring the fuel injection amount will be sequentially explained.

First, a description will be given of a case where the automobile is not in a driving state, that is, a state where the vehicle key is not inserted into the key box. At this time, when the microcomputer 9 reaches the start measurement calculation routine shown in FIG. 3 during the calculation processing of the main routine, the process advances to a starter judgment step 201 where the judgment becomes NO since no start signal is generated from the start switch 2. Then, the program proceeds to starter flag determination step 213, and since the starter flag is not set, the determination becomes NO, and one calculation process of the start measurement calculation routine is completed, and the division flag determination of the normal measurement calculation routine shown in FIG. 4 is performed. Proceeding to step 301, since the frequency division flag has not been set, the determination is NO, and one calculation process of the normal measurement calculation routine is completed. This calculation along with various control calculations is repeated at a period of several tens of milliseconds, but only the various control calculations are performed without calculations for measuring the fuel injection amount.

When the driver of this car gets on board and puts the vehicle key into the start position in the key box while the engine coolant temperature has dropped sufficiently below 35°C, a start signal is generated from the start switch 2 and the 3rd Starter judgment step 20 in the figure
1, the judgment is reversed from NO to YES, and the process proceeds to timer judgment step 202, where the judgment is
If the answer is NO, proceed to water temperature input step 203, input the engine cooling water temperature T, and proceed to water temperature judgment step 20.
Proceeding to step 4, the engine coolant temperature T is below 35°C, so the determination becomes YES, and the process advances to first determination step 205, where the first flag is set, so the determination becomes YES, and the first flag is cleared. After completing the arithmetic processing in step 206 and starter flag setting step 207, the process advances to timer setting step 208. Then, in this timer setting step 208, timer data A corresponding to the engine cooling water temperature T at that time is set by a function f, and then, through a conversion step 209, a timer operation step 210 is performed.
Proceed to step 211, set the timer operation for the first time, and proceed to subtraction step 211 to perform subtraction (B=B-
1) Then, the process proceeds to timer determination step 212, where the determination becomes NO, and one calculation process of the start measurement calculation routine is completed. Then, after going through the normal measurement calculation routine and various control calculation routines, when the first judgment step 205 of this start measurement calculation routine is reached again, the judgment is reversed from YES to NO, and the process proceeds to timer operation step 210, where the process continues from the previous time. The timer operation step 210 waits until the current calculation processing time reaches 100 msec, and when 100 msec has elapsed, the subtraction step 211
After the timer determination step 212, the calculation is changed to one that completes one calculation process in the start measurement calculation routine. This calculation is repeated at a cycle of 100 msec along with the normal measurement routine and various control calculation routines.

During the above repetitive calculation, when the engine starts and the vehicle key is changed from the start position of the key box to the ignition position to stop turning the starter, a start signal is generated from the start switch 2. When the starter determination step 201 in FIG. 3 is reached, the determination is reversed from YES to NO, and the process advances to the starter flag determination step 213. Further, if the timer data B becomes "0" while the starter is being turned, when the timer determination step 212 is reached, the determination is reversed from NO to YES, and the process proceeds to the starter flag determination step 213. In this starter flag determination step 213, since the starter flag has been set, the determination becomes YES, and the process proceeds to a starter flag release step 214 to release the starter flag, and then proceeds to the first flag setting step 215 to set the first flag. Then, proceed to timer calculation step 216 to find the number of calculation repetitions N during the increased injection amount time at engine start, and proceed to increase injection amount calculation step 217 to calculate Fs=N.
Find the increased injection amount Fs based on the calculation formula of t・K,
The process advances to addition step 218, where the increased injection amount Fs is added to the cumulative injection amount F to update the cumulative injection amount F, and the process advances to cumulative injection amount determination step 219. At this time,
When the cumulative injection amount F is less than 0.1, the determination becomes NO and one calculation process of the start measurement calculation routine is completed, so there is no change in the fuel consumption display on the display 11, but the cumulative injection amount F is 0.1
When the result is YES, the process proceeds to display output step 220 to issue a display signal to the display 11, proceeds to cumulative injection amount update step 221, subtracts 0.1 from cumulative injection amount F, and executes the start measurement calculation routine. Since one calculation process is completed, the fuel consumption amount added by 0.1 is displayed on the display 11.

On the other hand, when the frequency division pulse from the frequency division counter 8 is applied to the INT terminal of the microcomputer 9 during the repeated calculations of the main routine, the calculation processing of the main routine is temporarily interrupted and the process starts from interrupt start step 101 in FIG. Execute the interrupt calculation process, proceed to frequency division flag set step 102 to set the frequency division flag, proceed to return step 103, finish the interrupt processing of the interrupt routine, and resume the calculation of the main routine that was temporarily interrupted earlier. Resume processing. As a result, when the frequency division flag determination step 301 in the normal measurement calculation routine in FIG. The process advances to cumulative injection amount determination step 304. At this time, if the cumulative injection amount F is less than 0.1, the determination becomes NO and one calculation process of the normal measurement calculation routine is completed, so there is no change in the fuel consumption display on the display 11, but the cumulative injection amount When the amount F is 0.1 or more, the determination becomes YES, and the process proceeds to display output step 305, where a display signal is sent to the display 11, and the process proceeds to cumulative injection amount update step 306, where 0.1 is subtracted from the cumulative injection amount F, and normal measurement is performed. Since one calculation process of the calculation routine is completed, the fuel consumption amount added by 0.1 is displayed on the display 11.

Therefore, every time the frequency division pulse from the frequency division counter 8 is applied to the INT terminal of the microcomputer 9, an interrupt is generated and the minute injection amount △F corresponding to one frequency division pulse signal is integrated into the cumulative injection amount F. Then, each time this cumulative injection amount F becomes 0.1 or more, the display 1
The fuel consumption display in step 1 is updated in increments of 0.1.

In this embodiment, the increased injection amount is not measured using the injection pulse signal to the cold start injector that injects increased amount when the engine is started, but is measured based on the engine cooling water temperature set in advance and the increased amount based on the engine cooling water temperature at that time. Since the increased injection amount is measured in relation to the injection amount, it is possible to know the increased injection amount from the cold start injector with sufficient accuracy, and without using the injection pulse signal to the cold start injector. This has the effect of being able to perform measurements at low cost without requiring any extra sensors.

Furthermore, although a start switch that emits a start signal when the vehicle key is inserted into the start position of the key box is shown as a start detection means, it is also possible that the vehicle key is inserted into both the start terminal and the ignition terminal of the key box at the same time, or that the ignition is activated. The start signal may be issued when it is detected that the battery is connected to the terminal but not the accessory terminal, or the start signal may be issued when it is detected that the engine has rotated.

In addition, the injection pulse signal from the EFI computer 3, the pulse signal from the delay circuit 4, the oscillation circuit 5
The output pulse signal from the AND circuit 6 is applied to the integration counter 7 and the frequency-divided pulse signal via the frequency division counter 8 is applied to the microcomputer 9. The pulse signal may be applied to the microcomputer 9, and the microcomputer 9 may perform arithmetic processing to integrate the fuel injection amount.

Furthermore, an injection pulse signal to a cold start injector that injects an increased amount at the time of engine startup may be applied to the microcomputer 9, and the increased injection amount may be determined by internal calculation processing. Furthermore, the fuel consumption amount may be determined by adding the number of reference pulse signals included in the injection pulse signal to the injector and the number of reference pulse signals included in the injection pulse signal to the cold start injector. Furthermore, a pseudo pulse of the injection pulse to the cold start injector may be generated based on the signal from the water temperature sensor 1, and the increased injection amount may be determined by the microcomputer 9 based on this pulse. Furthermore, the temperature sensor is water temperature sensor 1.
The temperature sensor is not limited to this, and may be a temperature detector that detects the temperature around the microcomputer 9, or a sensor that detects the outside temperature or the inside temperature.

As described above, in the first invention of the present application, since the increased injection amount based on the starting temperature at the time of engine startup is added to the fuel consumption amount based on the fuel injection amount from the fuel injection device, when the engine is started, An excellent effect is that an accurate fuel consumption amount can be determined by adding and correcting the increased injection amount. Furthermore, the second invention of the present application has the excellent effect of providing a control device that can appropriately implement the fuel consumption measurement method of the first invention.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
Figure 2 is an interrupt calculation flowchart showing the calculation processing of the interrupt routine based on the divided pulse signal by the control program, Figure 3 is a calculation flowchart showing the calculation processing of the start measurement program by the control program, and Figure 4 is the control program. It is a calculation flowchart which shows the calculation process of the normal measurement calculation routine by a program. 1...Water temperature sensor as a temperature detector, 2...
Start switch as start detection means, 9...
Microcomputer as a calculation processing means, 1
1...Indicator.

Claims (1)

[Scope of Claims] 1. In a fuel consumption measurement method for measuring fuel consumption based on the amount of fuel injected from a fuel injection device, detecting that the engine is starting, and increasing injection amount based on the starting temperature at the time of detection. A method for measuring fuel consumption amount, characterized in that the amount is determined and the increased injection amount is added and corrected to the fuel consumption amount. 2. A fuel consumption measurement device that measures fuel consumption based on the amount of fuel injected from a fuel injection device, comprising: a start detection means that issues a start signal when the engine starts; a temperature detector that detects the temperature of the vehicle and generates a temperature signal; and arithmetic processing means for calculating an increased injection amount based on the temperature signal from the temperature detector when a starting signal from the starting detection means is detected, and adding and correcting the increased injection amount to the fuel consumption amount. Fuel consumption measuring device.