JP2012245896A - Display device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device for vehicle that can eliminate sense of incompatibility to display of average fuel consumption of a user.SOLUTION: A display control circuit 50 that controls the display of the average fuel consumption to a liquid crystal display 30 included in a combination meter 100 calculates regularly the average fuel consumption based on the total mileage and the total fuel consumption from a prescribed time. The variation value that shows the variation of the average fuel consumption calculated this time to the average fuel consumption calculated last time is calculated. Then, it is determined that the average fuel consumption is steady by detecting that the variation value is converging to a predetermined range. In addition, the average fuel consumption display to the liquid crystal display part 30 is prohibited until it is determined that the average fuel consumption is stable, and when determined that the average fuel consumption is stable, display to the liquid crystal display 30 is started then.

Description

  The present invention relates to a display device for a vehicle that displays the state of a vehicle, and is particularly suitable for displaying a vehicle mileage per unit fuel consumption or an average fuel consumption that is a fuel consumption per unit mileage of a vehicle. The present invention relates to a display device for a vehicle.

  Conventionally, the average fuel consumption, which is the vehicle travel distance per unit fuel consumption, is calculated from the fuel consumption after the reset and the vehicle travel distance, and the display means mounted on the vehicle displays the calculation result. Is known (see Patent Document 1). In particular, the technique disclosed in Patent Document 1 has a small amount of fuel consumption after reset and a data amount of the vehicle travel distance, and the calculation result of the average fuel consumption is greatly influenced by the driving state of the vehicle and is displayed by the display means. The problem is to eliminate the user's uncomfortable feeling due to the significant increase or decrease in average fuel consumption. In order to solve this problem, in the technique described in Patent Document 1, the display unit does not display the average fuel consumption immediately after resetting, but the display unit displays the calculated average fuel consumption after a predetermined time has elapsed. is doing. According to this, since the data amount of the fuel consumption amount and the travel distance becomes relatively large and the calculated average fuel consumption is stabilized, the user's uncomfortable feeling can be eliminated.

JP 58-20538 A

  However, in the technique of Patent Document 1 in which the average fuel consumption is displayed by the display means after a predetermined time has elapsed after resetting, there are cases where a large amount of data cannot be collected within the predetermined time. In this case, if the average fuel consumption is displayed immediately after the lapse of the predetermined time, the average fuel consumption greatly increases and decreases, and there is a possibility that the user's uncomfortable feeling cannot be resolved.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a vehicular display device that can eliminate the user's uncomfortable feeling with respect to the display of average fuel consumption.

In order to achieve the above object, the invention of claim 1 is based on the total travel distance and the total fuel consumption from a predetermined time, and the travel distance per unit fuel consumption or the fuel consumption per unit travel distance. Average fuel consumption calculating means for periodically calculating the average fuel consumption,
Display means for displaying the average fuel consumption calculated by the average fuel consumption calculation means;
By calculating a fluctuation value that represents the fluctuation amount of the average fuel consumption calculated this time with respect to the average fuel consumption previously calculated by the calculation means, and detecting that the fluctuation value has converged within a predetermined range, it is determined that the average fuel consumption has stabilized. Determination means to perform,
Until the determination means determines that the average fuel consumption is stable, the display of the average fuel consumption is prohibited on the display means, and when the determination means determines that the average fuel consumption is stable, the average fuel consumption to the display means from then on. Display control means for starting the operation.

  According to the first aspect of the present invention, the display control means does not display the average fuel consumption on the display means until the determination means determines that the average fuel consumption is stable, and determines that the average fuel consumption is stable. Then, since the display of the average fuel consumption on the display means is started, only the stable average fuel consumption can be visually recognized by the user. Therefore, according to this invention, the discomfort with respect to the display of an average fuel consumption of a user can be eliminated.

  According to the invention of claim 2, since the determining means determines the stability of the average fuel consumption by continuously detecting that the fluctuation value of the average fuel consumption has converged within a predetermined range a plurality of times. By detecting once that the value has converged to the predetermined range, the determination accuracy is higher than that for determining the stability of the average fuel consumption.

  According to the invention of claim 3, when the average fuel consumption is not stable and the display of the average fuel consumption on the display means is prohibited, the standby image indicating that the display of the average fuel consumption is waiting is displayed. Will be displayed on the means. According to this, it is possible to prevent the user who desires the display of the average fuel consumption from giving anxiety due to the fact that the average fuel consumption is not displayed.

  As described in the invention of claim 4, the fluctuation value of the average fuel consumption calculated by the determination means is the ratio of the average fuel consumption calculated last time to the average fuel consumption calculated this time or the average fuel consumption calculated last time. Since this is the ratio of the average fuel consumption calculated this time, when these ratios approach the numerical value 1, the fluctuation amount decreases. In this invention, since the predetermined range to be compared to determine that the calculated fluctuation value is stable has a predetermined width including the numerical value 1, it is detected that the fluctuation value has converged to this predetermined range. By doing so, it can be determined whether or not the average fuel consumption is stable.

  As described in the invention of claim 5, the fluctuation value of the average fuel consumption calculated by the determination means is a difference between the average fuel consumption calculated last time and the average fuel consumption calculated this time. The amount of fluctuation decreases as the value of 0 approaches 0. In this invention, since the predetermined range to be compared to determine that the calculated fluctuation value is stable has a predetermined width including the numerical value 0, it is detected that the fluctuation value has converged to this predetermined range. By doing so, it can be determined whether or not the average fuel consumption is stable.

It is a front view of the combination meter by a 1st embodiment of the present invention. It is a block diagram which shows the electric constitution of the combination meter by 1st Embodiment of this invention. In the combination meter by 1st Embodiment of this invention, it is a table | surface regarding the travel distance, fuel consumption, and average fuel consumption integrated | accumulated every minute after a display control circuit acquires a reset signal. It is the graph which showed transition of the average fuel consumption updated for every 1 minute after a display control circuit acquires a reset signal about the table shown in FIG. It is a flowchart which shows the control flow of the stabilization determination process which a display control circuit performs in the combination meter by 1st Embodiment of this invention. The flowchart which shows the control flow of the display process which a display control circuit performs in the combination meter by 1st Embodiment of this invention. The combination meter by 1st Embodiment of this invention WHEREIN: It is a display example of the image which a liquid crystal display part displays, (a) is a display example which displayed the average fuel consumption on the liquid crystal display part, (b) is a liquid crystal display. It is the example of a display which displayed the standby image on the display part.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the component corresponding in each embodiment.

(First embodiment)
FIG. 1 is a front view of a combination meter 100 according to the first embodiment. The combination meter 100 is accommodated in an instrument panel provided in the vehicle interior of the vehicle, and is arranged with the front side shown in FIG. 1 facing the driver's seat side.

  A combination meter 100 as a vehicle display device is mounted on a vehicle together with a traveling internal combustion engine, and displays various vehicle information related to the vehicle. The combination meter 100 includes a pointer display unit 20 including a tachometer 21, a fuel gauge 22, a water temperature gauge 23, a speedometer 24, and the like, and a liquid crystal display unit 30.

  The tachometer 21, the fuel gauge 22, the water temperature gauge 23, the speedometer 24, and the like constituting the pointer display unit 20 are provided with pointers 21a to 24a and dial plates 21b to 24b, respectively. Each pointer 21a to 24a rotates along the surface on the driver's seat side of each dial plate 21b to 24b. The dials 21b and 24b of the tachometer 21 and the speedometer 24 are formed with scale designs 21c and 24c extending annularly around the rotation centers of the rotating hands 21a and 24a. In addition, numerical designs 21d and 24d are formed on the dial plates 21b and 24b on the inner peripheral side of the scale designs 21c and 24c. On the other hand, the dials 22b and 22b of the fuel gauge 22 and the water temperature gauge 23 are formed with scale designs 22c and 23c extending in an arc around the rotation centers of the rotating hands 22a and 23a. In addition, character designs 22d and 23d are formed on the dial plates 22b and 23b adjacent to both ends in the extending direction of the scale designs 22c and 23c.

  With the above configuration, the pointer display unit 20 displays the vehicle information by indicating the scale designs 21c to 24c and the numerical designs 21d and 24d or the character designs 22d and 23d with the pointers 21a to 24a. Specifically, the tachometer 21 displays information indicating the rotation speed of the output shaft of the internal combustion engine mounted on the vehicle. The fuel gauge 22 displays fuel remaining amount information indicating the remaining amount of fuel stored in a fuel tank mounted on the vehicle. The water temperature gauge 23 displays information indicating the temperature of cooling water for cooling the internal combustion engine mounted on the vehicle. The speedometer 24 displays information indicating the traveling speed of the vehicle.

  The scale designs 21c to 24c, the number designs 21d and 24d, and the character designs 22d and 23d of the dial plates 21b to 24b of the pointer display unit 20 are lit and displayed by being transmissively illuminated in an environment with little external light. The In addition, each of the pointers 21a to 24a is configured to be able to emit light, and emits light in an environment with little extraneous light.

  The liquid crystal display unit 30 displays vehicle information by an image formed on a display screen of a liquid crystal panel 70 described later. Examples of images for displaying vehicle information displayed on the liquid crystal display unit 30 include an odometer image 31, an average fuel consumption image 32, a trip meter image (not shown), a shift indicator image (not shown), and a door warning image (not shown). Not). In addition to the image for representing vehicle information, the image displayed on the liquid crystal display unit 30 includes a standby image 33 (see FIG. 7B) that informs the user that the average fuel consumption is being integrated. .

  Next, the electrical configuration of the combination meter 100 will be described with reference to FIG.

  The combination meter 100 includes a display control circuit 50, stepper motors 60a to 60d, a liquid crystal panel 70, a backlight 71, and the like. The combination meter 100 is connected to a control area network (CAN) 91 that is an in-vehicle network, an external battery 95, an ignition relay 94, and a grounded ground wiring 98.

  The display control circuit 50 acquires the vehicle information, and controls the pointer display unit 20 (see FIG. 1) and the liquid crystal display unit 30 (see FIG. 1), whereby the acquired vehicle information is displayed on the pointer display unit 20 and the liquid crystal display. Display on the unit 30. The display control circuit 50 includes a processor that performs various types of arithmetic processing, a flash memory that stores information about programs and vehicles used in the arithmetic processing, and a RAM that functions as a calculation work area. In addition, the display control circuit 50 includes a drive circuit (not shown) for controlling each pixel of the liquid crystal panel 70 and a regulator circuit (not shown) for controlling the light emission of the backlight 71. Further, the display control circuit 50 includes a drive circuit (not shown) for controlling the rotation of the stepper motors 60a to 60d, and a regulator circuit (not shown) for controlling the light emission of the light emitting diode for causing the pointer display unit 20 to emit light. Have.

  The display control circuit 50 includes a power supply system that is always in conduction with the battery 95 and a power supply system via an ignition relay 94, and is supplied with power from the battery 95. In addition, the display control circuit 50 is connected to the CAN 91 mounted on the vehicle, and acquires vehicle information related to the vehicle output to the CAN 91. The vehicle information includes, for example, engine information indicating whether the engine is operating or stopped, a travel distance indicating the travel distance of the vehicle, and a fuel remaining amount indicating a remaining fuel amount stored in a fuel tank mounted on the vehicle. And door opening / closing indicating whether the vehicle door is open or closed. Further, the vehicle information includes information indicating the traveling speed of the vehicle, the coolant temperature, the rotational speed of the output shaft of the internal combustion engine, and the fuel consumption of the internal combustion engine.

  Further, the display control circuit 50 calculates the average fuel consumption based on the travel distance of the vehicle and the fuel consumption. Specifically, the total travel distance from when the display control circuit 50 acquires the reset signal from the reset switch 72 that can be operated by the user electrically connected to the display control circuit 50, the total fuel consumption, Is used to calculate the average fuel consumption. The calculation of this average fuel consumption is performed periodically. For example, it is performed every minute from the acquisition of the reset signal by the display control circuit 50. The average fuel consumption calculated periodically is stored in the flash memory of the display control circuit 50 in the calculated order. The average fuel consumption calculated in the present embodiment is a travel distance per unit fuel consumption.

  Each of the stepper motors 60a to 60d has a pointer shaft (not shown) that rotates according to a control signal from the drive circuit of the display control circuit 50. The pointers 21a to 24a (see FIG. 1) are attached to the pointer shafts of the stepper motors 60a to 60d. Each of the stepper motors 60a to 60d displays the vehicle information on the pointer display unit 20 (see FIG. 1) by rotating the pointers 21a to 24a together with the pointer shafts.

  The liquid crystal panel 70 is a dot matrix type transmissive liquid crystal panel having a plurality of pixels arranged in a matrix. The liquid crystal panel 70 displays vehicle information as images (see FIGS. 1 and 7A and 7B) by driving each pixel in accordance with a control signal from the drive circuit of the display control circuit 50.

  The backlight 71 is disposed on the back side in the display direction of the liquid crystal panel 70 and illuminates the liquid crystal panel 70 from the back side in the display direction. The backlight 71 has a light emitting diode and a diffusion plate, and illuminates the liquid crystal panel 70 without any spots. Each image (see FIGS. 1 and 7A and 7B) formed on the liquid crystal panel 70 by the light emitted from the backlight 71 is displayed in a light-emitting manner.

  On the CAN 91, a power supply control circuit 92 is provided. The power supply control circuit 92 is connected to a battery 95, an ignition switch 93, an ignition relay 94, an engine control circuit (not shown), and the like. The power supply control circuit 92 is supplied with power from the battery 95. The power supply control circuit 92 detects a pressing operation of the ignition switch 93 by a driver (user) or the like for switching the ignition ON / OFF state of the vehicle. The power supply control circuit 92 applies a voltage to the ignition relay 94 when the ignition of the vehicle is turned on, and puts the ignition relay 94 in an energized state. In addition, the power supply control circuit 92 outputs engine information indicating whether the internal combustion engine is in an operating state or a stopped state to the CAN 91 based on the detected pressing operation of the ignition switch 93 by the driver. The engine control circuit starts the traveling internal combustion engine according to the engine information output from the power supply control circuit 92 to the CAN 91.

  In the above configuration, the display control circuit 50 displays the vehicle information when the acquired engine information is switched from the information indicating the stopped state of the internal combustion engine to the information indicating the operating state (FIG. 1). And the liquid crystal display unit 30 (see FIG. 1) are controlled. The display control circuit 50 also acquires vehicle information other than the engine information as described above. The display control circuit 50 calculates a rotation direction, a rotation angle, a rotation speed, and the like of each pointer shaft of each stepper motor 60a to 60d based on the acquired vehicle information. The display control circuit 50 outputs pulse power corresponding to the calculation result to the stepper motors 60a to 60d to control the pointer shaft. In addition, the display control circuit 50 controls each pixel of the liquid crystal panel 70 based on the acquired travel distance, the calculated average fuel consumption, and the like. Further, the display control circuit 50 starts light emission of the light emitting diode and the backlight 71 that illuminates the pointer display unit 20. Thus, the display of the vehicle information by the pointer display unit 20 and the liquid crystal display unit 30 as shown in FIG. 1 is turned on.

  Next, the display of the average fuel consumption on the liquid crystal display unit 30 by the display control circuit 50 will be described in detail. As described above, the average fuel consumption calculated every minute by the display control circuit 50 is displayed on the liquid crystal display unit 30 based on the total distance traveled and the total fuel consumption from the acquisition of the reset signal (FIGS. 1 and FIG. 1). 7 (a)).

  Here, the calculated average fuel efficiency will be described. As described above, the average fuel consumption is calculated by the total travel distance and the total fuel consumption from the acquisition of the reset signal. At the time immediately after the acquisition of the reset signal, the integrated values of the total travel distance and the total fuel consumption are very small. The operating state of the internal combustion engine varies depending on the operation of the user. For this reason, the total fuel consumption with respect to the total travel distance is not stable. For example, when the vehicle is going downhill immediately after acquiring the reset signal, the fuel supply to the internal combustion engine is normally stopped. For this reason, the total fuel consumption with respect to the total travel distance is very small. On the other hand, when the vehicle is climbing uphill immediately after acquiring the reset signal, the fuel supply to the internal combustion engine is usually larger than when the vehicle is running on a flat road. For this reason, the total fuel consumption with respect to the total travel distance is extremely larger than the case described above. As described above, the average fuel consumption calculated in a state where the total travel distance and the total fuel consumption after the reset signal are acquired is greatly influenced by the operating state of the internal combustion engine, and has low reliability. If the average fuel consumption is displayed on the liquid crystal display unit 30 immediately after obtaining the reset signal, the average fuel consumption greatly increases and decreases every time the display is updated, which gives the user a sense of incongruity.

  This will be described in detail with reference to FIGS. FIG. 3 is a table regarding travel distance, fuel consumption, and average fuel consumption accumulated every minute after the display control circuit 50 acquires the reset signal. FIG. It is the graph which showed transition of the average fuel consumption updated every minute.

  As shown in FIG. 4, immediately after obtaining the reset signal, the fuel consumption with respect to the travel distance accumulated every minute is not stable, and the fluctuation amount of the average fuel consumption calculated every minute is large. Further, as shown in FIG. 4, the periodically calculated fluctuation amount of the average fuel consumption decreases as the accumulated travel distance and fuel consumption increase.

  Therefore, in this embodiment, the display control circuit 50 prohibits the display of the average fuel consumption immediately after acquiring the reset signal on the liquid crystal display unit 30, and determines whether or not the average fuel consumption is relatively stable. Determine by processing. When it is determined that the average fuel consumption is stabilized by the stabilization determination process, the average fuel consumption is displayed on the liquid crystal display unit 30 by the display process. The display control circuit 50 displays the standby image 33 as shown in FIG. 7B on the liquid crystal display unit 30 until it is determined that the average fuel consumption is stabilized by the stabilization determination process. Thus, when displaying the average fuel consumption, the display of the unstable average fuel consumption is prohibited and only the stable average fuel consumption is displayed, so that the user's discomfort with respect to the display of the average fuel consumption is eliminated. In this embodiment, when the average fuel consumption is unstable and display on the liquid crystal display unit 30 is prohibited, a standby image 33 as shown in FIG. 7B is displayed on the liquid crystal display unit 30. Thus, it is possible to prevent the user who desires the display of the average fuel consumption from giving anxiety due to the display of the average fuel consumption not being performed.

  Specifically, by using the stabilization determination process, among the average fuel efficiency (AF) calculated periodically, the average fuel efficiency (AFn) calculated this time with respect to the previously calculated average fuel efficiency (AFn-1). By obtaining a fluctuation value (C) representing the fluctuation amount and detecting that the obtained fluctuation value (C) has converged within a predetermined range, it is determined that the average fuel consumption calculated this time is stable.

  In the present embodiment, the fluctuation value (Cm) is the ratio (AFn−1 / AFn) of the average fuel consumption (AFn−1) calculated last time to the average fuel consumption (AFn) calculated this time. The variation value obtained in this way is a value related to the average fuel consumption calculated last time and the inclination with respect to the average fuel consumption calculated this time. The predetermined range in this case has a predetermined width including the numerical value 1. This is because, as the calculated fluctuation value approaches the numerical value 1, it means that the fluctuation amount of the average fuel consumption calculated this time with respect to the average fuel consumption calculated last time becomes smaller. Note that the ratio (AFn / AFn-1) of the average fuel efficiency calculated this time to the average fuel efficiency calculated last time may be the variation value (Cm). Even in this case, as the calculated fluctuation value approaches the numerical value 1, the amount of fluctuation of the average fuel consumption calculated this time with respect to the average fuel consumption calculated last time becomes smaller.

  Next, a stabilization determination process for determining whether or not the average fuel consumption calculated by the display control circuit 50 is stable when the display control circuit 50 displays the average fuel consumption on the liquid crystal display unit 30 based on FIG. explain. The stabilization determination process shown in the flow chart of FIG. 5 is performed when the pressing operation of the ignition switch 93 is detected by the power supply control circuit 92 and the display control circuit 50 acquires engine information indicating the operating state from the circuit 92, or This is implemented by the display control circuit 50 when the user operates the reset switch 72 and the display control circuit 50 acquires a reset signal from the reset switch 72.

  First, the case where the ignition switch 93 is pressed by the user and the display control circuit 50 acquires information indicating the operating state from the power supply control circuit 93 will be described. When the display control circuit 50 acquires information indicating the operating state, step S10 is executed. In step S10, the state of the stabilization flag stored in the display control circuit 50 is determined. Here, the stabilization flag is a flag indicating whether or not the calculated average fuel consumption is stable. When it is determined that the calculated average fuel consumption is stable, the flag is “1”, and when it is determined that the average fuel consumption is unstable, the flag is “0”. This flag is stored in the display control circuit 50 even when the internal combustion engine is stopped. In step S10, the state of the stabilization flag is determined to confirm the result of the previous stabilization determination process.

  If it is determined that the stabilization flag is “1” in the determination process of step S10, the average fuel consumption calculated from this can be regarded as stable, and thus this stabilization determination process is terminated. . On the other hand, if it is determined that the stabilization flag is “0”, the process proceeds to step S20. In step S20, the travel distance and the integrated value of the fuel consumption stored in the display control circuit 50 and the count number of a stabilization count described later are reset, and the process proceeds to step S30.

  After determining that the stabilization flag is “1” in step S10 and completing the stabilization determination process, the display control circuit 50 calculates the average fuel consumption by executing the display process described later, and calculates the calculated average fuel consumption. Is displayed on the liquid crystal display unit 30. In the present embodiment, in the display process, the average fuel consumption is calculated based on the travel distance and fuel consumption from the reset signal. Unless a reset signal is newly detected, the travel distance and the fuel consumption amount are stored in the flash memory of the display control circuit 50. Even if the internal combustion engine is stopped and then started, as long as the average fuel consumption based on the stored travel distance and fuel consumption is continuously calculated, the stabilization flag is set regardless of whether the ignition switch 93 is ON / OFF. It remains “1”.

  In step S30, the standby image 33 as shown in FIG. 7B is displayed on the liquid crystal display unit 30. The standby image 33 shown in FIG. 7B is not a display of the calculated average fuel consumption, but an indication that the average fuel consumption is being integrated, that the average fuel consumption cannot be displayed because the calculated average fuel consumption is not stable, Or it is a display for showing that it waits for the display start of average fuel consumption. The display example illustrated in FIG. 7B is an example, and any information may be used as long as the above is notified to the user.

  In step S40, the average fuel consumption is calculated from the total travel distance and the total fuel consumption after a predetermined time (1 minute) after the initialization in step S20, and the calculation result is stored in the display control circuit 50. The calculation of the average fuel consumption in step S40 is executed every predetermined time (in this embodiment, every minute) when the stabilization determination process is being executed. In step S50, the ratio (AFn-1 / AFn) of the previously calculated average fuel consumption (AFn-1) to the currently calculated average fuel consumption (AFn) is calculated as the fluctuation value (Cm), and the fluctuation value is predetermined. It is determined whether or not the value of the range has converged. If it is determined in step S50 that the variation value has converged to the predetermined range, the process proceeds to step S60. If it is determined that the variation value has not converged to the predetermined range, the process proceeds to step S70.

  In step S60, since an affirmative determination is made in step S50, the count number of the stabilization count is added, the count number is stored in the flash memory of the display control circuit 50, and the process proceeds to step S80. In step S70, since a negative determination is made in step S50, the count number of the stabilization count is reset, the count number after reset is stored in the flash memory of the display control circuit 50, and the process returns to step S40.

  In step S80, the count number of the stabilization count in a state where one count number is added in step S60 is determined. Specifically, it is determined whether or not the count number of the stabilization count is a predetermined number or more. In this embodiment, the predetermined number is a numerical value of 2 or more. In the determination process of step S80, if the count number of the stabilization count is equal to or greater than the predetermined number, the process proceeds to step S90, and if the count number of the stabilization count is less than the predetermined number, the process returns to step S40. Here, the stabilization count is to count the number of times that the fluctuation value continuously converges within a predetermined range in step S50.

  In step S50, which is executed first after initialization, the average fuel consumption calculated last time is not stored in the display control circuit 50, and thus the fluctuation value cannot be calculated. In this case, the process in step S60 is not executed, and the process proceeds to step S80. In this case, since the count number of the stabilization count is less than the predetermined number, a negative determination is made when step S80 is executed, and the process returns to step S40.

  In step S90, since the stable average fuel consumption is calculated, the calculated average fuel consumption is displayed on the liquid crystal display unit 30. As a result, the average fuel consumption image as shown in FIG. 7A is displayed on the liquid crystal display unit 30. In step S100, the stabilization flag is changed from “0” to “1”, and the control flow of the stabilization determination process is terminated. Thereafter, a control flow of display processing described later is executed.

  In the present embodiment, step S90 is not executed unless it is determined in step S80 that the count number of the stabilization count is equal to or greater than a predetermined number. That is, step S90 is not executed unless it is determined that the fluctuation value calculated in step S50 is continuously stable. By providing such processing in step S80, it is determined that the fluctuation value is stable only once, and as a result, the determination accuracy of the average fuel consumption stability is increased as compared with the case where the average fuel consumption is displayed.

  Here, a case where the user operates the reset switch 72 in a state where the average fuel consumption is displayed on the liquid crystal display unit 30 will be described. When the display control circuit 50 detects a reset signal generated when the user operates the reset switch 72, a stabilization determination process is executed. In this case, step S110 is executed.

  In step S110, the stabilization flag is changed from “1” to “0”, and the process proceeds to step S20. In step S20, as described above, the travel distance, the integrated value of the fuel consumption, and the count number of the stabilization count that have been stored in the flash memory of the display control circuit 50 are reset. Thereafter, the processing after step S30 is executed again from the state in which the integrated values of the travel distance and the fuel consumption are reset.

  In addition, when the reset signal from the reset switch 72 is detected during the process from step S40 to step S80, the process of step S110 is forcibly performed, and again in step S20, the travel distance and The integrated value of the fuel consumption amount and the count number of the stabilization count are reset.

  The control flow of the stabilization determination process has been described above. Next, the control flow of the display process executed after the stabilization determination process is completed will be described with reference to FIG.

  In S210, the average fuel consumption is calculated from the travel distance and fuel consumption stored in the flash memory of the display control circuit 50. The travel distance and fuel consumption stored in the flash memory are those after the reset signal is detected, and the display control circuit 50 calculates the average fuel consumption based on the stored travel distance and fuel consumption. In step S220, the average fuel consumption calculated in step S210 is displayed on the liquid crystal display unit 30, and the control flow ends. In step S10 of the stabilization determination process, when it is determined that the stabilization flag is “1”, this display process is immediately executed. When the stabilization flag is “1”, the flash memory stores sufficient mileage and fuel consumption data. Therefore, when the internal combustion engine is temporarily stopped and restarted, many data are stored. Even when the fuel is consumed, the calculated fluctuation amount of the average fuel consumption is very small. Therefore, when the ignition switch 93 is operated and the internal combustion engine is started, it is determined in step S10 that the stabilization flag is “1”, and even if the display process is executed immediately, the reliability of the displayed average fuel consumption is Not lost.

  In the present embodiment, the display control circuit 50 that executes step S40 corresponds to the “average fuel consumption calculation means” recited in the claims, and the display control circuit 50 that executes steps S50, S60, and S80 claims. The display control circuit 50 that executes steps S30 and S90 corresponds to the “display control means” described in the claims, and the liquid crystal display unit 30 corresponds to the claims. This corresponds to the “display means” described in the above.

(Other embodiments)
The first embodiment of the present invention has been described above. However, the present invention is not construed as being limited to the embodiment, and can be applied to various embodiments without departing from the scope of the present invention. .

  In the first embodiment, the ratio (AFn−1 / AFn) of the previously calculated average fuel consumption (AFn−1) to the currently calculated average fuel consumption (AFn) is calculated, or the previously calculated average fuel consumption (AFn−). By calculating the ratio (AFn / AFn-1) of the average fuel consumption (AFn) calculated this time relative to 1), the variation value (Cm) of the average fuel consumption is obtained, but the present invention is not limited to this.

  For example, the difference between the currently calculated average fuel efficiency (AFn) and the previously calculated average fuel efficiency (AFn-1) may be used as the variation value (Cm). In this case, the determination of the stability of the average fuel efficiency is performed by determining whether or not the calculated fluctuation value has converged to a predetermined range having a predetermined width including the numerical value 0. Assuming that the fluctuation value is the difference between the average fuel consumption calculated this time and the average fuel consumption calculated last time, the fluctuation amount of the average fuel consumption decreases as the numerical value of the difference approaches the numerical value 0. Therefore, in this case, the stability of the average fuel consumption can be determined by setting the predetermined range to have a predetermined width including the numerical value 0.

  In the previous embodiment, the travel distance per unit fuel consumption is the average fuel consumption. However, the present invention is not limited to this, and the fuel consumption per unit travel distance may be the average fuel consumption. Furthermore, in the previous embodiment, the average fuel consumption is calculated every predetermined time (every minute), but is not limited thereto, and may be calculated every predetermined distance (for example, every 1 km). .

  20 Pointer display section, 21 Tachometer, 22 Fuel gauge, 23 Water temperature gauge, 24 Speedometer, 21a-24a Pointer, 21b-24b Dial, 21c-24c Scale design, 21d, 24d Number design, 22d, 23d Character design, 30 Liquid crystal display unit (display means), 31 odometer image, 32 average fuel consumption image, 33 standby image, 50 display control circuit (average fuel consumption calculation means, determination means, display control means), 60a-60d stepper motor, 70 liquid crystal panel, 71 Backlight, 73 Reset switch, 91 CAN, 92 Power supply control circuit, 93 Ignition switch, 94 Ignition relay, 95 Battery, 98 Ground wiring, 100 Combination meter (Vehicle display device)

Claims (5)

Mean fuel consumption calculation means for periodically calculating the travel distance per unit fuel consumption or the average fuel consumption that is the fuel consumption per unit travel distance based on the total travel distance and the total fuel consumption from a predetermined time When,
Display means for displaying the average fuel consumption calculated by the average fuel consumption calculation means;
By calculating a fluctuation value representing a fluctuation amount of the average fuel consumption calculated this time with respect to the average fuel consumption previously calculated by the calculation means, and detecting that the fluctuation value has converged within a predetermined range, the average fuel consumption is stabilized. Determination means for determining;
Until the determination means determines that the average fuel consumption is stable, the display means prohibits display of the average fuel consumption. When the determination means determines that the average fuel consumption is stable, the display means starts from that time. Display control means for starting average fuel consumption for the vehicle.   2. The vehicle display according to claim 1, wherein the determination unit determines that the average fuel consumption is stable by continuously detecting that the fluctuation value of the average fuel consumption has converged to a predetermined range a plurality of times. apparatus.   When the display of the average fuel consumption on the display unit is prohibited until the determination unit determines that the average fuel consumption is stable, the display control unit waits for the display of the average fuel consumption to start. 3. The vehicle display device according to claim 1, wherein a standby image indicating the above is displayed on the display unit. The variation value calculated by the determination means is a ratio of the average fuel efficiency calculated last time to the average fuel efficiency calculated this time, or a ratio of average fuel efficiency calculated this time to the average fuel efficiency calculated last time,
The vehicle display device according to any one of claims 1 to 3, wherein the predetermined range has a predetermined width including a numerical value 1. The fluctuation value calculated by the determination means is a difference between the average fuel efficiency calculated last time and the average fuel efficiency calculated this time,
4. The vehicle display device according to claim 1, wherein the predetermined range has a predetermined width including a numerical value of 0. 5.

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