JP2006242839A - Device and method for indicating residual amount of fuel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method for indicating a residual amount of a fuel, capable of indicating the residual amount of the fuel exactly in accordance with its state. <P>SOLUTION: The device comprises: an indicator 5 for displaying an indication value M; a liquid level sensor 2 which detects a liquid level of the fuel in a fuel tank of a vehicle and generates a liquid level detection signal; a vehicle speed sensor 1 which detects a speed of the vehicle and generates a vehicle speed detection signal; and a microcomputer 4 which computes a first measurement value F1 based on the fuel detection signal from the liquid level sensor 2, and then computes the indication value M by using the first measurement value F1, brings the indicator 5 to display the indication value M and stores the first measurement value F1 and the indication value M into a RAM 41. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel remaining amount display device capable of displaying a fuel remaining amount in a fuel tank of a vehicle.

  Conventionally, as a method of measuring the remaining amount of fuel in a fuel tank mounted on a vehicle such as an automobile, a motorcycle, an aircraft, a ship, an agricultural machine, or a construction machine, a float that moves up and down with the fuel tank level (liquid level) The contact that is linked to the vertical movement of the float via the contact arm slides on the sliding resistance of the sender part, and outputs a change in resistance value that changes with the liquid level as a detection signal. In general, a fuel gauge pointer including an indicating instrument is operated based on a detection signal (see, for example, Patent Document 1).

  In the prior art, the remaining amount of fuel is measured based on the floating height of the float. However, under environmental conditions such as when the vehicle accelerates and decelerates and inertia acts, or when the vehicle tilts on a slope, the liquid level changes due to the movement of fuel in the fuel tank. There is a problem that the actual fuel remaining amount cannot be measured accurately by tilting or vibrating.

  In order to solve this problem, a conventional fuel remaining amount display device is known that displays a value when stable for a long time by delaying the response of the float to the fluctuation of the liquid level. However, when the vehicle travels for a long time on a slope or stops for a long time on a sloping ground, the level of the liquid fluctuates, making it difficult to accurately detect the remaining fuel amount.

  In addition, the fuel remaining amount that has been increased must be displayed immediately after refueling, but if the display is delayed, it may take a long time to display the correct remaining fuel amount. there were. Therefore, when the ignition switch is turned on, the remaining amount of fuel detected at that time is displayed, but there is a problem that it is impossible to prevent erroneous display after parking on the above-mentioned sloping land. .

Various devices have been proposed to solve these problems. For example, in the fuel remaining amount display device described in Patent Document 2, the remaining amount of fuel immediately after the ignition switch is turned on is detected, and this detection is performed. The measured value is compared with the indicated value (measured value) of the remaining amount display stored when the ignition switch is turned off. Regardless, it indicates the new fuel level immediately after the ignition switch is turned on. On the other hand, when the difference between the two remaining amounts is less than a predetermined value, the remaining amount of fuel when the ignition switch was turned off last time is displayed.
JP-A-8-50045 JP-A-3-282219

  However, in the conventional fuel remaining amount display device, when the ignition switch is turned off while the liquid level of the fuel in the fuel tank is shaking, such as immediately after the vehicle suddenly stops, the indicated value of the remaining amount of fuel is Since it is detected based on the liquid level in the fuel tank, the indication value of the remaining amount of fuel detected when the fuel liquid level fluctuates is stored in the storage means in a state including a considerable error. There was a problem that. Further, in the conventional vehicle fuel remaining amount display device, the fuel remaining amount instruction value is determined based on the fuel remaining amount instruction value stored in the storage means immediately after the ignition switch is turned on. If the indicated value of the remaining fuel amount contains an error, the remaining fuel amount immediately after the ignition switch is turned on may not be displayed correctly.

  For example, after the ignition switch is turned off, the fuel value is larger than the actual fuel remaining value indicated by the fluctuation of the liquid level in the fuel tank and stored in the storage means. When the fuel is replenished, the difference between the instruction value of the remaining amount of fuel detected immediately after the ignition switch is turned on and the stored instruction value becomes smaller than the actual fuel increase. For this reason, it is not recognized that fuel has been replenished while the ignition switch is turned off, and the remaining fuel indication value displayed when the ignition switch is turned off is displayed, indicating the remaining fuel level immediately after the ignition switch is turned on. In rare cases, the fuel replenished while the ignition switch is off is displayed without being reflected.

  The present invention has been made in view of the above problems, and provides a fuel remaining amount display device capable of accurately displaying the remaining amount of fuel according to the state and a display method therefor. It is in.

  A fuel remaining amount display device according to the present invention includes a display means for displaying a display value and a fuel sensor for detecting a liquid level in a fuel tank of a vehicle and generating a fuel signal. And a vehicle speed sensor for detecting a speed of the vehicle to generate a vehicle speed signal, a first measurement value is calculated based on the fuel signal from the fuel sensor, and the display using the first measurement value A control unit that calculates a value and displays the display value on the display unit, and stores the first measurement value and the display value in a storage unit, and the control unit includes: When it is determined that a predetermined time has elapsed since the vehicle stopped based on the vehicle speed signal, the value of the first measurement value is stored in the storage unit as a second measurement value.

  Further, as described in claim 2, in the fuel remaining amount display device according to claim 1, the control means includes the first measurement value newly calculated after the ignition switch is turned on and the storage. The supply / waste oil determination is performed based on the second measurement value stored in the means, and a display based on the result of the supply / waste oil determination is prompted to the display means.

  According to a third aspect of the present invention, in the fuel remaining amount display device according to the second aspect, the control means stores a connection state of a fuse provided up to the power source of the vehicle as fuse information in the storage means. In addition, after the ignition switch is turned on, whether to perform the supply / waste oil determination is selected according to the fuse information.

  According to a fourth aspect of the present invention, in the fuel remaining amount display device according to the third aspect of the present invention, the control means is configured to connect the fuse based on the fuse information after the ignition switch is turned on. When it is determined that there is not, the newly calculated first measurement value is displayed on the display means without performing the supply / waste oil determination.

  According to the fuel remaining amount display method of the present invention, the first measurement value is calculated based on the fuel signal from the fuel sensor provided in the fuel tank of the vehicle. A calculation process for calculating the display value using the measured value, a display process for displaying the display value on a display means, and determining whether or not a predetermined time has elapsed since the vehicle stopped based on a vehicle speed sensor. And a storage process for storing the value of the first instruction value as the second instruction value in the storage means when it is determined that a predetermined time has elapsed by the stable state determination process. A method for displaying the remaining amount of fuel, which is stored in the storage means by the first measurement value newly calculated based on the fuel signal from the fuel sensor and the storing process after the ignition switch is started. Above And a supply / waste oil determination process for comparing the measurement value of 2 to determine fuel replenishment or discharge, and a display value is updated according to a result of the supply / waste oil determination process, and the display process is performed. .

  According to a sixth aspect of the present invention, in the fuel remaining amount display method according to the fifth aspect of the present invention, in the storing process, a connection state of a fuse provided up to the power source of the vehicle is stored in the storage means as fuse information. A method for displaying the remaining amount of fuel to be stored, wherein after the ignition switch is started, a selection process for selecting whether or not to perform the supply / waste oil determination process is performed according to the fuse information.

  The present invention relates to a fuel remaining amount display device capable of displaying the remaining amount of fuel in a fuel tank of a vehicle, and a fuel remaining amount display device capable of accurately displaying the remaining amount of fuel according to the state and display thereof. Can provide a method.

  Hereinafter, a fuel remaining amount display device and a display method thereof according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a diagram showing an electrical configuration of a fuel remaining amount display device for a vehicle. A vehicle speed sensor 1, a liquid level sensor (fuel sensor) 2, an injector 3, a microcomputer (control means) 4, And a display (display means) 5.

  The vehicle speed sensor 1 outputs vehicle speed information corresponding to the rotation speed of the detected portion that rotates in synchronization with the wheel rotation of the vehicle as a vehicle speed detection signal (vehicle speed signal).

  The liquid level sensor 2 includes a float, a sliding resistance, and the like for measuring the remaining amount of fuel in the fuel tank of the vehicle, and indicates a resistance value of the sliding resistance that is linked to the float that changes according to the liquid level. Information is output as a liquid level detection signal (fuel signal).

  The injector 3 communicates with a fuel tank through a filter and a pump through a fuel supply pipe, and opens and closes a nozzle opening / closing valve to inject fuel from the fuel tank into the engine. The injector 3 also outputs consumption information corresponding to the fuel injection amount as an injection detection signal.

  The microcomputer 4 is, for example, a control unit composed of a microcomputer mounted on a circuit board in a meter housing, and performs various arithmetic processes based on detection signals from the vehicle speed sensor 1, the liquid level sensor 2, and the injector 3. As a CPU (Central Processing Unit), a RAM (storage means) 41 serving as a readable and rewritable working memory for storing arithmetic processing results in the CPU, and a ROM serving as a read-only program memory storing a control program. ing. The microcomputer 4 includes an input / output interface for electrically connecting to the vehicle speed sensor 1, the liquid level sensor 2, the injector 3, and the like. This input / output interface has a port connected to the vehicle power supply (battery) via an ignition switch and a fuse, and a port connected to the display unit 5, and the ignition switch is on or the fuse is connected. If so, electric power is supplied to the microcomputer 4 and various arithmetic processes can be performed.

  The microcomputer 4 receives detection signals from the vehicle speed sensor 1, the liquid level sensor 2, and the injector 3, and is obtained according to a predetermined program stored in the ROM and various data stored in the RAM 41 based on these signals. The remaining amount of fuel is output to the display 5. Further, the microcomputer 4 can also input information from various sensors such as the vehicle speed sensor 1, calculate the unit consumption of fuel (fuel consumption) and the travelable distance, and output them to the display 5.

  The display 5 is composed of a combination meter mounted in front of the driver's seat of the vehicle, and operates via a drive circuit (not shown) based on a control signal from the microcomputer 4. The indicator 5 includes a pointer that rotates in accordance with the remaining amount of fuel (display value) and vehicle speed obtained by calculation processing of the microcomputer 4 to be described later, and a dial plate that has an index that is an indication target of the pointer. It is equipped with an indicator that displays the vehicle speed and the remaining amount of fuel in analog by reading the contrast, and a display panel composed of liquid crystal elements and organic EL elements to display the unit consumption of fuel and the distance that can be traveled numerically. Yes.

  Further, the display 5 is provided with an alarm means 51 having a light source such as a light emitting diode or a lamp, and can be notified of an alarm state by being turned on or blinking based on a control signal from the microcomputer 4. .

  By mounting the above-described configuration on the vehicle, a remaining fuel amount display device can be provided. In addition, the microcomputer 4 can perform arithmetic processing based on input values such as detection signals of various sensors, and can drive and control the display 5.

  Next, arithmetic processing by the microcomputer 4 for driving and controlling the display 5 will be described with reference to FIGS. FIG. 2 shows the data storage area of the RAM 41, and FIG. 3 shows normal processing until the fuel remaining amount is calculated and displayed.

  The microcomputer 4 inputs the liquid level detection signal from the liquid level sensor 2 several times (for example, four times) at regular time intervals, and uses the liquid level detection signal for several times as sampling information to obtain a sampling information storage area D of the RAM 41. (Step S1).

  Next, the microcomputer 4 calculates the average value of the sampling information D for several times, and calculates the remaining fuel amount corresponding to the liquid level as the first measured value F1 by a predetermined algorithm considering the shape of the fuel tank. Then, the first measurement value F1 is stored in the first measurement value storage area of the RAM 41 (step S2).

  Next, the microcomputer 4 calculates a fuel remaining amount in consideration of the fuel supply determination and the injection detection signal from the injector 3 according to the first measurement value F1 by a predetermined algorithm, and displays the display value M in the display value storage area of the RAM 41. (Step S3). The microcomputer 4 subtracts the remaining fuel amount according to the injection amount (fuel consumption amount) calculated by the injection detection signal, and corrects this value based on the first measurement value F1 to display. The value M can be calculated. In step S3, the display value M can be calculated in consideration of fuel supply and discharge. The microcomputer 4 can obtain the display value M to be displayed on the display 5 by the arithmetic processing from step S1 to step S3 described above.

  Further, the microcomputer 4 determines whether or not the microcomputer 4 is connected to the power supply via the fuse, and stores information indicating the connection state by the fuse as a fuse flag (fuse information) V in the fuse flag storage area. (Step S4). The fuse flag V can determine whether or not power is supplied to the microcomputer 4 when the ignition switch is in the OFF state.

  Moreover, the microcomputer 4 determines whether the vehicle is traveling based on the vehicle speed detection signal from the vehicle speed sensor 1 as the stable state determination process (step S5), and when the vehicle is stopped (the vehicle speed is In the case of 0 km / h), it is determined whether or not a predetermined time (for example, 10 seconds) has elapsed in this stop state (step S6). The predetermined time is set in advance so that the flow of fuel in the fuel tank that occurs after the vehicle stops and then the fuel flow in the fuel tank becomes gentle, and accordingly, the vertical movement of the liquid level becomes very small. Is done.

  When the microcomputer 4 determines that the predetermined time has elapsed in the stop state by the determination process in step S6, the first measurement value F1 is stored as the second measurement value F2 in the second measurement value storage area of the RAM 41 as the storage process. Store (step S7). Note that the second measured value F2 is a value obtained when the fuel level in the fuel tank is measured in a stable state regardless of an inclined land or a flat land.

  Next, the microcomputer 4 determines whether or not the ignition switch is turned off (step S8). If the ignition switch is turned off, the microcomputer 4 performs power saving processing such as sampling processing and stops the ignition switch and turns on the ignition switch. Shifts to the standby mode (standby mode).

  Moreover, the microcomputer 4 outputs a control signal that prompts the display unit 5 to display the display value M calculated in step S3 as display processing (step S9). Note that the state of the ignition switch is determined before this processing, and if it is in the off state, the display 5 can be prevented from displaying. The microcomputer 4 can also notify that the remaining amount of fuel is low by the alarm means 51 provided in the display 5 if the display value M is less than a predetermined amount (for example, 8 liters).

  By repeating the above-described processing from step S1 to step S9, a display value corresponding to the remaining amount of fuel can be calculated and output to the indicator 5, and the fuse flag V and the second remaining fuel amount F2 can be set. Can be stored.

  Hereinafter, the processing procedure after turning on the ignition switch will be described with reference to FIG.

  When the ignition switch is turned on from the standby mode or the power-off state, the microcomputer 4 first inputs the liquid level detection signal from the liquid level sensor 2 several times (for example, four times) at regular intervals. The liquid level detection signal of the batch is stored as sampling information D in the sampling information storage area of the RAM 41 (step S11).

  Next, the microcomputer 4 calculates an average value of the sampling information D for several times, calculates a first measurement value F1 corresponding to the remaining fuel amount by a predetermined algorithm considering the shape of the fuel tank, and this first value. Is stored in the first measured value storage area of the RAM 41 (step S12).

  Next, as a selection process, the microcomputer 4 reads the fuse flag stored in the RAM 41 and determines the connection state of the fuse before the transition to the previous standby mode or until the ignition switch is turned off (step S13). The microcomputer 4 selects whether or not to perform a later-described feed / waste oil determination process based on the determination result of the connection state.

  When the microcomputer 4 determines that the connection state is established by the fuse in the determination in step S13, the possibility that the second measured value F2 is measured before and after the ignition switch of the second measured value F2 is turned off is high as the supply / waste oil determination process. As a result, the first measured value F1 stored in step S12 is compared with the second measured value F2 stored in the RAM 41, and the difference (absolute value) is less than a predetermined threshold value (for example, 3 liters). It is determined whether or not (step S14). If the supply / waste oil determination process is greater than or equal to a predetermined threshold value, it is determined that the fuel has been replenished (fuel supply) or discharged (waste oil) in the fuel tank.

  If the microcomputer 4 determines in step S13 that the fuse is not connected, or if the difference between the first measurement value F1 and the second measurement value F2 is greater than or equal to a predetermined threshold value in step S14. If it is determined, the value of the first measurement value F1 stored in the RAM 41 is stored in the display value M (step S15). That is, if it is determined that fuel has been replenished or discharged, the microcomputer 4 updates the value of the display value M to the value of the first measurement value F1 newly calculated in step S12.

  Further, the microcomputer 4 reads the display value M stored in the RAM 41 as display processing, and outputs a control signal for prompting display based on the display value M to the display 5 (step S16).

  By the above-described processing, when the ignition switch is turned on, an accurate fuel remaining amount can be promptly displayed according to the state.

  Such a fuel remaining amount display device includes a display 5 that displays a display value M, a liquid level sensor 2 that detects a liquid level of fuel in a fuel tank of the vehicle and generates a liquid level detection signal, and the vehicle. A vehicle speed sensor 1 that detects a speed and generates a vehicle speed detection signal, and a first measurement value F1 is calculated based on a fuel detection signal from the liquid level sensor 2, and a display value is calculated using the first measurement value F1. M is calculated, and the display value M is displayed on the display device 5 and the microcomputer 4 stores the first measurement value F1 and the display value M in the RAM 41. The microcomputer 4 receives the vehicle speed from the vehicle speed sensor 1. When it is determined that a predetermined time has elapsed since the vehicle stopped based on the detection signal, the value of the first measurement value F1 is stored in the RAM 41 as the second measurement value F2, and the microcomputer 4 has an ignition switch Newly after being turned on First perform feed waste oil determined by the measured value F1 and the second measurement value F2 stored in the RAM41 issued, one which facilitates the display based on the results of this paper waste oil determination on the display unit 5.

  Therefore, if it is determined in step S14 that the difference between the first measurement value F1 and the second measurement value F2 is less than the predetermined threshold value, the display value M calculated before the transition to the standby mode is performed. Thus, the display 5 can be displayed. That is, immediately after turning on the ignition switch, for example, even if the place where the ignition switch is operated is on a sloping ground, information before turning off the ignition switch (sampling information D, first measurement value F1, and injection detection from the injector) It is possible to promptly display the fuel remaining amount with an accurate value using the display value M obtained by the signal).

  Further, when the difference between the first measurement value F1 and the second measurement value F2 is equal to or greater than a predetermined threshold value, there is a high possibility that the fuel in the fuel tank has been replenished or discharged. The display value M stored in the RAM 41 and the actual fuel remaining amount in the fuel tank are greatly different. Therefore, the microcomputer 4 can display the value of the first measurement value F1 newly calculated on the display 5 without using the data stored in the RAM 41 in step S15, and is closer to the accurate value. The remaining amount of fuel can be displayed promptly.

  The microcomputer 4 stores the connection state of the fuse provided up to the power source of the vehicle in the RAM 41 as the fuse flag V, and the fuse is connected based on the fuse flag V after the ignition switch is turned on. When it is determined that there is not, the newly calculated value of the first measurement value F1 is displayed on the display 5 without performing the supply / waste oil determination.

  Therefore, when the fuse that should be provided from the microcomputer 4 to the power source is not in a connected state (when the fuse is not installed or disconnected), for example, the ignition switch is turned off immediately after the vehicle stops and the microcomputer 4 is turned off. Since there is a possibility that the second measured value F2 is not the previous data, for example, the power supply to the power source is cut off, the newly calculated second value F2 is used without considering the data stored in the RAM 41. Since the value of the measured value F1 of 1 can be displayed on the display device 5, the fuel remaining amount closer to an accurate value can be quickly displayed according to the connection state of the fuse.

  In the above-described embodiment, the example using the RAM 41 constituting the microcomputer 4 as a storage unit has been described as an example. However, a non-volatile memory provided separately can also be used.

  Further, in the above-described embodiment, in step S14 as the supply and waste oil determination process, the newly calculated first measurement value F1 is compared with the second measurement value F2 stored in the RAM 41, and the difference (absolute (Value) is less than a predetermined threshold value (for example, 3 liters), but a predetermined threshold value can be set according to the shape of the fuel tank and the accuracy of the liquid level sensor. Further, the present invention does not have to set a threshold value for the absolute value of the difference as described above, and a new first measured value F1 and a second measured value F2 stored in the RAM 41 It may be determined whether the difference (F1-F2) is within a predetermined range of, for example, minus 5 liters or more and less than 3 liters. That is, if the difference (F1-F2) is less than minus 5 liters, the fuel is discharged from the fuel tank, and if it is 3 liters or more, it can be determined that the fuel has been replenished.

  Further, in the embodiment of the present invention, the fuel remaining amount display device including the above-described components and processing methods has been described as an example, but the present invention is not limited to this, and the configuration and processing are not limited thereto. For example, in the above-described embodiment, the fuel remaining amount calculated in consideration of the injection detection signal is calculated by a predetermined algorithm in the above-described embodiment. The display value to be displayed on the display (display means) based on the information of the liquid level detection signal (fuel signal) from the liquid level sensor (fuel sensor) provided in the fuel tank without using the information of It may be calculated.

The figure which shows a structure in the fuel residual amount display apparatus of embodiment of this invention. The figure which shows the various areas in RAM of embodiment same as the above. The flowchart which shows a part of process which the microcomputer of embodiment same as the above performs. The flowchart which shows a part of process which the microcomputer of embodiment same as the above performs.

Explanation of symbols

1 Vehicle speed sensor 2 Liquid level sensor (fuel sensor)
4 Microcomputer (control means)
41 RAM (storage means)
5 Display (display means)
F1 First measurement value F2 Second measurement value M Display value V Fuse flag (fuse information)

Claims (6)

Display means for displaying a display value; a fuel sensor for detecting a fuel level in a fuel tank of the vehicle to generate a fuel signal; a vehicle speed sensor for detecting a speed of the vehicle and generating a vehicle speed signal; A first measurement value is calculated based on the fuel signal from the fuel sensor, the display value is calculated using the first measurement value, the display value is displayed on the display means, and the first measurement value is displayed. Control means for storing the measured value of 1 and the display value in a storage means,
The control means stores the value of the first measurement value as the second measurement value when it is determined that a predetermined time has elapsed since the vehicle stopped based on the vehicle speed signal from the vehicle speed sensor. A fuel remaining amount display device characterized in that it is stored in the means.   After the ignition switch is turned on, the control means makes a feed / waste oil determination based on the newly calculated first measurement value and the second measurement value stored in the storage means, and this feed / waste oil determination 2. The fuel remaining amount display device according to claim 1, wherein a display based on a result is prompted to the display means.   The control means stores the connection state of the fuses provided up to the power source of the vehicle as fuse information in the storage means, and performs the supply / waste oil determination according to the fuse information after the ignition switch is turned on. The remaining fuel amount display device according to claim 2, wherein the fuel remaining amount display device is selected.   If it is determined that the fuse is not connected based on the fuse information after the ignition switch is turned on, the control means does not perform the supply / waste oil determination and performs the newly calculated first 4. The fuel remaining amount display device according to claim 3, wherein a measured value is displayed on the display means. Calculation processing for calculating a first measurement value based on a fuel signal from a fuel sensor provided in a fuel tank of the vehicle, and calculating the display value using the first measurement value, and display means for displaying the display value When it is determined that a predetermined time has passed by the display process to be displayed, the stable state determination process for determining whether a predetermined time has elapsed since the vehicle stopped based on the vehicle speed sensor, and the stable state determination process And a storage process for storing the value of the first instruction value in the storage means as a second instruction value.
After the ignition switch is started, the first measured value newly calculated based on the fuel signal from the fuel sensor is compared with the second measured value stored in the storage means by the storing process. A method for displaying the remaining amount of fuel, characterized in that a fuel supply / waste oil determination process for replenishing or discharging fuel and a display value are updated according to a result of the fuel / waste oil determination process and the display process is performed. In the storing process, the remaining amount of fuel is stored in the storage means as fuse information in a connection state of a fuse provided up to the power source of the vehicle,
6. The method for displaying the remaining amount of fuel according to claim 5, wherein after the ignition switch is started, a selection process for selecting whether or not to perform the supply / waste oil determination process is performed according to the fuse information.

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