JPH01257222A - Electronic type fuel residue meter - Google Patents

Abstract

PURPOSE:To display a true fuel residue, by attaching a speed sensor for measuring a vehicle speed and an inclination sensor for detecting inclination of a vehicle to monitor outputs of both the sensors by an arithmetic processing means. CONSTITUTION:The frequency of sampling by an arithmetic processing means B during the running of a vehicle is set at a large value enough to keep a fuel residue display from varying with the oscillation of a liquid surface due to vibration of the vehicle, allowing a large delay time. The means B detects a stoppage of the vehicle from an output of a speed sensor D to change the frequency of sampling to a small value. As a result, during the stoppage of the vehicle, a display response time is shortened with a reduction in a calculation time of a fuel residue, which enables a quick display of a true residue during the supply of oil. When the calculated fuel residue is increased as compared with the fuel residue previously calculated and moreover, when an inclination sensor E detects inclination of the vehicle, the increase of the fuel residue is determined to be caused by the inclination of the vehicle. So, the previous fuel residue is displayed as it is, eliminating the need for displaying the calculated fuel residue on a display device C by updating.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary of the Invention] The present invention provides an electronic fuel level gauge of a vehicle with a speed sensor and an inclination sensor, and monitors the outputs of these two sensors to determine the state of the vehicle (stopping). The system switches the displayed follow-up speed depending on whether the vehicle is traveling or driving) to obtain the optimum follow-up speed, and also stops display updates when the vehicle is tilted to prevent the remaining fuel amount from being displayed higher than the actual amount.

[Industrial application field]

The present invention relates to an electronic fuel level meter installed in a vehicle such as an automobile.

[Conventional technology]

FIG. 4 shows the configuration of a conventional electronic fuel level gauge.

In the figure, 1 is a fuel remaining amount sensor that detects the remaining amount of fuel in the fuel tank, 2 is an interface circuit that converts the output of the fuel remaining amount sensor 1 into an analog voltage signal, and 3 is an interface circuit that converts the analog signal into a digital signal. 4 is an A/D converter, 4 is a microprocessor that calculates the remaining fuel amount, 5 is a display drive circuit, and 6 is a display that displays the remaining fuel amount.

The remaining fuel amount sensor 1 detects the remaining amount of fuel by changing its resistance value in conjunction with a float in the fuel tank. The resistance value indicating the remaining fuel amount obtained by the fuel remaining amount sensor 1 is converted into an analog voltage by the ink face circuit 2, sent to the A/D converter 3, converted to a digital signal, and then sent to the microprocessor 4. It will be done.

The microprocessor 4 samples the digital signal indicating the remaining amount of fuel sent from the A/D converter 3 a predetermined number of times at a predetermined time interval, obtains the average value, and uses this as the fuel remaining amount. Output as a quantity. Then, the remaining fuel amount obtained in this way is
For example, 10 segments as shown in FIG. 5 are displayed via the display drive circuit 5.

The zone display type display 6 lights up in zones to notify the occupants of the remaining fuel amount.

[Problem that the invention seeks to solve]

Conventional electronic fuel level gauges respond to changes in the input signal from the fuel level sensor 1 in order to prevent the remaining fuel level display from changing due to fluctuations in the liquid level caused by vibrations while the vehicle is running.
It is displayed with a considerable time delay. Therefore, if you refuel with the ignition key in the
The display cannot follow the increase in fuel during refueling in a short period of time, and even though the fuel tank is actually full, the remaining amount display remains empty (E), making it difficult to refuel. There was a problem in that the full (F) display only appeared after a while.

Further, conventional electronic fuel level gauges do not take into account the possibility of incorrect display of the remaining fuel level depending on the tilt of the vehicle. Therefore, when the vehicle tilts, depending on the direction of the tilt, the amount of remaining fuel may be displayed as more or less than the actual amount of fuel remaining. In general, if the amount of remaining fuel is displayed as less than the actual amount, there will not be much of a problem, but if the amount of remaining fuel is displayed as more than the actual amount, there may be problems such as the risk of accidentally running out of fuel. Some kind of countermeasure is necessary.

The present invention was invented based on the above circumstances, and is an electronic device that can quickly display the true remaining fuel amount when refueling and also prevents the remaining fuel amount from being displayed higher than the actual amount due to the tilt of the vehicle. The purpose of this project is to provide a type fuel level gauge.

[Means for solving problems]

In order to solve the above problems, the present invention adopts the configuration shown in the basic configuration diagram of FIG. 1.

That is, the remaining amount of fuel in the fuel tank is detected by the fuel remaining amount sensor Δ, and the detected output is sampled a predetermined number of times at a fixed time interval by the arithmetic processing means to calculate the average value. The electronic fuel level meter displays the average value obtained as the fuel level on the display C, which is equipped with a speed sensor D that measures the vehicle speed and an inclination sensor E that detects the inclination of the vehicle. 1iB monitors the outputs of the speed sensor D and inclination sensor E,
When the vehicle is stopped, the sampling frequency is changed to a smaller value than when the vehicle is running, and when the calculated remaining fuel amount value increases and the vehicle is tilted, the display C is changed. This setting makes it impossible to update the display of the remaining fuel amount.

[For production]

While the vehicle is running, the number of times of sampling by the calculation processing means B is set to a large value and a large delay time is given so that the remaining fuel level display does not fluctuate due to fluctuations in the liquid level caused by vehicle vibrations. .

When the vehicle stops, the calculation processing means B detects the speed sensor D.
Detect this from the output of and change the sampling frequency to a smaller value. As a result, when the vehicle is stopped, the time required to calculate the remaining fuel amount is shortened, so the display response time is shortened, and the true remaining fuel amount is quickly displayed when refueling.

In addition, if the calculated remaining fuel amount has increased compared to the previously calculated remaining fuel amount and the tilt sensor E has detected that the vehicle is tilted, the increase in the remaining fuel amount at this time The arithmetic processing means B determines that this is caused by the tilt of the vehicle, and the calculated remaining fuel amount is not updated and displayed on the display C, and the display C continues to display the previous fuel remaining amount.

〔Example〕

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

FIG. 2 shows an embodiment of the present invention, in which 7 is a speed sensor that measures the vehicle speed, 8 is an inclination sensor that detects the inclination of the vehicle, and 9 is a signal from the speed sensor 7 and inclination sensor 8. This is an interface circuit for shaping the waveform into a waveform convenient for processing.

Note that the other components indicated by numerals 1 to 6 are the same as those of the conventional one shown in FIG.

The operation of the embodiment having the above configuration will be explained with reference to the flowchart shown in FIG.

The remaining fuel amount is detected by the fuel remaining amount sensor 1 and converted into a resistance value. The interface circuit 2 converts this into an analog voltage signal and sends it to the A/D converter 3. The A/D converter 3 converts the analog signal into a digital signal and then sends it to the microprocessor 4.

The microprocessor 4 samples the digital signal indicating the remaining fuel amount sent from the A/D converter 3 every 0.1 seconds, and takes in the remaining fuel amount value every 0.1 seconds (step 21 in FIG. 3). .22).

Next, the microprocessor 4 averages the captured remaining amount data in order to avoid the influence of fluid level fluctuations caused by vibrations when the vehicle is running (step 26), but at this time, when the vehicle is stopped, The number of samplings for calculating the average value is changed depending on whether or not the average value is calculated. That is, the microprocessor 4 monitors the output of the speed sensor 7, sets the sampling frequency to 16 times when the vehicle is stopped, and performs step 2.
3゜24), while driving, set the sampling number to 256.
(step 23.25). The reason why the number of samplings is changed between when the vehicle is stopped and when the vehicle is running is to change the display response speed during refueling.

As mentioned above, when the vehicle is stopped, the average value of the 16 sampling times is used as the fuel remaining amount at that time, and when the vehicle is running, the average value of the 256 sampling times is used as the remaining fuel amount at that time. Each is calculated as a quantity. This obtained remaining fuel amount value is stored in the RO in the microprocessor 4.
By referring to the table stored in M or by calculation, it is converted into the number of display segments to match the display format of the 10-segment, zone lighting type display 6 shown in FIG. 5, for example (step 27). , is compared with the number of segments currently lit and displayed on the display 6 (step 28).
. If the new data and display data are equal, display 6
The number of lit segments is maintained as is, and the process proceeds to the next process A. If the new data is larger than the displayed data,
That is, if the newly calculated remaining fuel amount value is greater than the previously calculated remaining fuel amount value, it is checked whether or not the slope of the vehicle is detected by the slope sensor 8 (step 29). , if there is an inclination, the display on the display 6 is not updated and the process branches to the next process A.

If there is no slope, the RAM in the microprocessor 4
Prepare a counter in the area (initial value = 5) and add 1 to this counter value (step 30).In this way, when the count value reaches 15 (step 31),
After initializing the counter (step 32), the number of lit segments of the display 60 is increased by one segment (step 33).

Next, if the remaining fuel value changes in the decreasing direction in step 28, 1 is subtracted from the initial value -50 count (step 34), and when the count value reaches 0 (step 35), the counter is initialized. After conversion (step 36)
, reduce the number of lighting segments of display 60 by 1 segment (
Step 37).

By executing the processing described above, in the case of this embodiment, the following display follow-up speed for displaying the remaining fuel amount can be obtained as a result.

■ If the remaining fuel level decreases continuously and the vehicle is stopped, it takes 8 seconds for the l segment to decrease ■ If the remaining fuel level decreases continuously and the vehicle is running,
It takes 128 seconds for one segment to decrease ■ If the remaining fuel level increases continuously and the vehicle is tilted, the display will not be updated ■ If the remaining fuel level increases continuously and the vehicle tilts, the display will not be updated. When the fuel level increases continuously and the vehicle is not tilted, it takes 16 seconds for each segment increase.■ When the fuel level increases continuously and the vehicle is not tilted, it takes 25 seconds for each segment increase.
6 seconds (Incidentally, such a condition applies, for example, when a vehicle accelerates or decelerates.) In the embodiment described below, the display 6 uses a zone lighting display type as shown in FIG. Although the example has been given for a case where a digital number display or a pointer display is used, it goes without saying that the present invention can be similarly applied to a digital number display or a pointer display. In addition, values such as the sampling time (0, 1 second), each sampling number (16 times, 256 times), and the initial value of the counter (=5) set in the flowchart in Figure 3 can be freely changed according to the purpose. Of course, it can be set. Furthermore, the speed sensor 7 in the present invention
Instead of providing it independently, the output of a speed sensor, which has been conventionally installed for speedometers, may be used.

〔Effect of the invention〕

Since the present invention has a configuration 0 operation as explained above, when refueling is performed with the ignition key in the ignition key, unlike conventional fuel level gauges, the true remaining fuel level can be displayed immediately. At the same time, it is possible to prevent the remaining fuel amount from being displayed as being larger than the actual amount due to the tilt of the vehicle, and this has the excellent effect of further improving reliability in vehicle operation.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the basic configuration of the present invention, Figure 2 is a flowchart of its operation, Figure 3 is a block diagram of a conventional electronic fuel level gauge, and Figure 4 is a diagram of a specific example of the display. be. A...Remaining fuel amount sensor, B...Calculation processing means, C.
...Indicator, D...Speed sensor, E...Inclination sensor. Patent Applicant: Yazaki Sogyo Co., Ltd. Figure 1, Figure 5; l) Figure 5, Figure 2, Procedural Amendment (□) September 5, 1988, Litigation Office, Bunki Yoshida, 1, Hanyu's Ma, 1988 Patent Application No. 081148 2, Name of the invention: Electronic fuel level gauge 3, Person making the amendment: Relationship with Hanyu Patent applicant address: 1-4-28 Mita, Minato-ku, Tokyo Name (689)
Yazaki Sogyo Co., Ltd. 4, Agent 6, Contents of the amendment to the number of inventions that will increase due to the amendment (Patent Application No. 62-081148) 1. Mei III, page 12, lines 10 to 12, as follows (
correct. [Figure 2 is a block diagram showing one embodiment of the electronic fuel level gauge according to the present invention, Figure 3 is a flowchart of its operation, Figure 4 is a block diagram of a conventional electronic fuel level gauge, and Figure 5 The figure is a diagram showing a specific example of a display device. ”

Claims (1)

[Scope of Claims] The remaining amount of fuel in the fuel tank is detected by a fuel remaining amount sensor, and the detected output is sampled a predetermined number of times at regular time intervals in an arithmetic processing means to calculate an average value. An electronic fuel level meter that displays the obtained average value on a display as the remaining fuel level is equipped with a speed sensor for measuring vehicle speed and a tilt sensor for detecting the tilt of the vehicle, and the arithmetic processing means The outputs of the speed sensor and the inclination sensor are monitored, and when the vehicle is stopped, the sampling frequency is changed to a smaller value than when the vehicle is running, and when the calculated remaining fuel value increases, and An electronic fuel level gauge, characterized in that when the vehicle is tilted, the display of the remaining fuel level on the display is set to be unable to be updated.