JPS60120211A - Running-distance measuring method - Google Patents

Abstract

PURPOSE:To correct the change in counted value due to the change in vehicle speed, by stepping the display at the minimum unit digit every time the counted value of distance pulses agrees with a specified reference value, obtaining a correcting value corresponding to the vehicle speed every specified running distance, the updating the reference value. CONSTITUTION:A pulse number for every running distance of 10m from a distance sensor 1a and a correcting value for every specified vehicle speed range are stored in correcting tables 6a and 6b. A value 1 is added to a display value at the lowest digit of a decimal counter 4, in which the lowest digit indicates 10m. The result is divided by the running distance per distance pulse, half-adjustment is performed, and a reference value is generated by a reference value generator 5. The counted value of the pulses from the sensor 1a is obtained by a pulse counter 2 and compared with the reference value by a comparator 3. The counter 4 is stepped up by the coincidence signal. The pulse counter 2 is reset by the 10 outputs of the comparator 3. A correcting value corresponding to the output of a vehicle speed sensor 1b is read out of the table 6b at every running of 100m. The reference value is corrected by the correcting value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] This invention relates to a mileage measuring method for measuring the mileage of an automobile.

[Prior art]

Generally, the distance traveled by a vehicle is displayed by counting distance pulses generated by a distance sensor each time the vehicle travels a predetermined distance. However, even under standard tire pressure and standard load, if the vehicle speed changes, the tire diameter will change due to the change in centrifugal force that accompanies the change in vehicle speed, so the value of the distance pulse counted will differ, but conventionally it is corrected. Since there was no method, changes in the count due to changes in vehicle speed were left as errors.

[Object and structure of the invention]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a mileage measuring method that corrects changes in the count value due to changes in vehicle speed and eliminates errors in mileage due to changes in vehicle speed.

In order to achieve this purpose, the present invention increments the odometer when the count value of the distance pulse reaches a predetermined reference value, and each time the odometer increments, The reference value is updated, and each time the travel distance reaches a predetermined value, the reference value at the time of the subsequent first step is corrected in accordance with the vehicle speed. Hereinafter, the present invention will be described in detail using drawings showing embodiments.

〔Example〕

FIG. 1 is a block diagram showing the main parts of an apparatus configured to apply the present invention. In the figure, 1a is a distance sensor that generates a distance pulse, 1b is a vehicle speed sensor that generates a vehicle speed signal, 2 is a pulse counter, 3 is a comparator, 4 is a decimal counter, 5 is a reference value generator, and 6a is a distance sensor. A correction table 6b is a correction table for correcting fractions of pulses, and a correction table 6b is a correction table for correcting errors due to vehicle speed. The distance sensor 1a is designed to generate 91 pulses per rotation of the tire, and one magnet is placed around the circumference of a disk that rotates at the same number of rotations as the tire.
A reed switch is disposed near the disk, and a pulse is generated each time the magnet approaches the reed switch. The vehicle speed sensor 1b is designed to generate a vehicle speed signal based on the distance pulse supplied from the distance sensor 1&.

The pulse counter 2 counts the pulses supplied to the terminal 211, and resets the counted value when a reset signal is supplied to the terminal 2b. Comparator 3 is terminal 3a
An output signal is generated from the terminal 3c every time the value represented by the signal supplied to the terminal 3b becomes equal to the value represented by the signal supplied to the terminal 3b, and a reset signal is generated from the terminal 3d when the output signal is sent out 10 times. It is supposed to be done. 4 is a 5-digit decimal counter, each time a signal is supplied to the terminal 4a, the displayed value is incremented, and the signal representing the lowest digit displayed value is sent from the terminal 4b to the first one from the terminal 4c. The trap is such that a signal representing the displayed value of the upper digit is sent. The reference value generator 5 is configured to send a signal representing a reference value, which will be described later, from a terminal 5f based on the signals supplied to the terminals 5a to 5e. The correction table 6a stores reference values determined by a method described later, and the correction table 6b stores correction values.

The operation of the device configured as described above is as follows. First, an example in which the tire diameter does not change depending on the vehicle speed will be described. Assuming that the travel distance of an assumed automobile per tire rotation is 2230 mm, and the distance sensor 1 generates one distance pulse per tire rotation, the vehicle will travel 2230 mm per distance pulse. In such a car, the number of pulses per 10 meters of travel distance and the rounded value of the number of pulses are calculated as follows.

Table 1 In this table, the number of pulses generated every 10 meters is stored in the correction table 6a. The lowest digit of the decimal counter 4 represents 10 meters, and the reference value generator s
ui Reads the number of distance pulses generated when the vehicle travels a distance corresponding to the value obtained by adding 1 to the display value of the lowest digit of the o-adic counter 4 from the correction table 6a, and sends a signal representing the rounded value of that value. Let's do it like this. This value is calculated by adding 1 to the display value displayed in the smallest unit digit, dividing the value by the travel distance per 1 distance pulse, and then rounding the result.

If the reference value generator 5 and the correction table 61k are configured as shown below, when the traveling distance is less than 10 meters, 1
Since the least significant digit of the 0-base counter 4 is displaying zero, the reference value generator 5 displays a value of 1, which is the sum of zero and 1, that is, 1.
The number of distance pulses representing 0 meters, 4, 48, is read from the correction table (im), and a signal representing the reference value 5, which is the rounded value, is sent out.

When the automobile travels, a distance pulse generated from a distance sensor 1 is counted by a pulse counter 2. This count value is compared with the reference value in the comparator 3, so when the count number of the pulse counter 2 reaches 5, the comparator 3 generates an output signal,
The decimal counter 4 is incremented. As a result, the lowest digit of the decimal counter 4, which was 0, becomes 1 and becomes 10.
Indicates that the vehicle has traveled a meter.

Since the decimal counter 4 now represents 10 meters, the reference value generator 5 calculates the travel distance 1 from the correction table 6a.
The distance pulse number 8.97 corresponding to 1 ft 20 meters is read out, and a signal representing the rounded value 9 is transmitted. Then, when the distance traveled by the car increases and the count value of the pulse counter 2 reaches 9, the comparator 3 generates an output signal again, so that the displayed value of the decimal counter 4 increments to represent 20 meters. become.

In this way, the reference value is updated each time the decimal counter 4 increments, and each time the value of the pulse counter 2 reaches the reference value, the decimal counter 4 increments and the distance traveled is accumulated. Then, when the comparator 3 sends out the output signal 10 times, it sends out a reset signal from the terminal 3d, so the pulse counter 2 is reset, and this pulse counter 2 starts counting from the initial state. For convenience, the signal output from the pulse counter 2 represents the count value of distance pulses from 0 to 100 meters, so it may be within the range of the reference value output from the reference value generator 5, and 10 All you need to do is prepare 10 different types up to 100 meters apart.

FIG. 2 is a diagram showing the effect of this invention, and (a)
is the distance pulse, (b) is the actual distance traveled, (C) is the distance 1
Assuming you drive 910 meters with 5 ift pulses, 1
The bottom of the mileage when driving the ゜ advance counter 4, (d)
is the bottom water of the mileage when this invention is applied, and (
The numbers written in &) indicate the number of pulses, and the numbers written in (b) to (d) indicate the running distance in meters. In this invention, the data read from the correction table 6a is rounded off and used as a reference value, so rounding down and rounding up occur randomly, errors are canceled, and the final distance is almost the same as the actual mileage. The value of is obtained. On the other hand, in the case where the present invention is not applied, fractions are accumulated, and the error increases in proportion to the distance traveled.

The above operation is based on the assumption that the tire diameter does not change depending on the vehicle speed, but since the tire diameter actually changes, this change is corrected using the correction table 6b.

When the vehicle speed increases, the tire diameter increases due to centrifugal force, so even if the count number of the pulse counter 2 is the same as the count number at low speeds, the travel distance is longer than at low speeds. Therefore, the values obtained by correcting the rounded values in Table 1 may be supplied to the comparator 3 as new reference values. Therefore, 10
Each time the vehicle travels 0 meters, the vehicle speed data at that time is detected, a correction value corresponding to the vehicle speed is read out from the correction table 6b, and this compensation value is subtracted from the rounded value when traveling 10 meters in Table 1. Do it like this. At this time, the correction table 6b
The correction value to be written in is the same value for the vehicle speed range until the error with respect to the count value of counter 2, which is counted assuming that there is no change in tire diameter due to vehicle speed, reaches a predetermined value, and the error exceeds the predetermined value. The values are set to be different in the following vehicle speed ranges. The dividing boundary of the vehicle speed range is assumed to be a point where the error resulting from the correction becomes a value equivalent to half a rotation of the tire.

The above concept is illustrated in Figure 3.

In Figure 3, (&) is the vehicle speed, (b) a is the count value of counter 2 when the vehicle travels for a predetermined time at each speed assuming that the tire diameter does not change with the vehicle speed, and is the same when the tire diameter changes with the vehicle speed. Error from the count value of counter 2 counted under the conditions, (C) is correction table 6 for each vehicle speed range
This is the correction value written in b. The vehicle speed range is the range up to the vehicle speed MA at which the counting error of counter 2 reaches 0.5, and from the vehicle speed V^ at which the argument error reaches 1.5 to the vehicle speed V.
Divide sequentially like the range up to B. At this time, all vehicle speeds at which the counting error is greater than the predetermined value m by 90.5 or more are in the same vehicle speed range. Then, in each vehicle speed range, Vl, V2,
Vs...Set the representative value of vm, and when the vehicle speed exceeds the representative value, read out the correction value shown in (e), and calculate this correction value from the rounded value when traveling 10 meters shown in Table 1. The new correction value is the value obtained by subtracting .

In this way, the reference value will be corrected according to the speed and speed of the 100-meter run (100-meter advance), and it will be possible to make corrections when following the next step. Even if the vehicle speed changes, the error in travel distance can be kept within an error of half a rotation of the tire.

FIG. 4 is a block diagram when actually constructing the device shown in FIG. The pulse counter 2 and comparator 3.1 in FIG.
The functions of the 0-base counter 4 and the reference value generator 5 are included in the microprocessor T, and the RAM 8 m, 8
b, ROM9 is correction table 6a + f; b
It consists of

FIG. 5 is a 70-chart showing the operation of the apparatus shown in FIG. In FIG. 5, in step 100, the distance traveled per distance pulse is read out, in step 101, the reference value, which is the rounded value shown in Table 1 and previously written in ROM 9, is written into RAM 9aK, and in step 102
The pulse counter 2 and decimal counter 4 are reset. At this time, the reference value written to the ROM 9 is determined based on the criteria explained in FIG.

In step 103, is the distance A from the distance sensor 1? ! , +rus, the count value of the pulse counter 2 is incremented in step 104. Next, when it is determined in step 105 that the lowest digit of the decimal counter 4 is not zero, in step 106 the count value of the pulse counter 2 is
The count value J of the decimal counter 4 is compared with the reference value corresponding to the mileage in the 10-meter mileage digit written in the RAM 8m in step 107, and when it is determined that these values are equal, the count value J of the decimal counter 4 is advance. And step 108
When the value of the lowest digit of decimal counter 4 becomes zero, that is, when the distance traveled reaches 100 meters, step 1
Reset the pulse counter 2 at step 09 and proceed to step 110.
Correct the reference value with . In this correction, first, a correction value corresponding to the vehicle speed at this point is read out from the correction table 6b in FIG. This is done by subtracting the correction value from (which is determined to remain unchanged) as a new correction value, and writing this new correction value into the RAM 8b. Thereafter, the flow performs other processing shown in step 111 and returns to step 103.

The other processing shown in step 111 is other than the odometer processing performed by the microprocessor I, and includes, for example, processing related to the running of the automobile, such as plug ignition timing control. Note that steps 103 and 10
If rNOJ is determined in step 6,108, the flow is set to proceed to step 111 in any case.

When the process of step 111 is completed, the flow again performs the determination shown in step 103, and when a distance pulse is supplied, the pulse counter 2 is incremented as shown in step 104. At this time, the decimal counter 4 has not yet incremented, so the value of the lowest digit is 0), step 10
5 is determined to be rYEsJ. As a result, step 112
Then, it is determined whether the value of the pulse counter 2 has become equal to the corrected reference value read out from the RAM 8b.

When it is determined that step 112 rNo J, that is, when the count value of step counter 2 has not reached the corrected reference value, the flow proceeds to steps 103, 104, 105.
Cycling through loops 112 and 111, step 1 each time
At 04, the pulse counter 2 increments.

While performing this operation, step 112 is rY
It is determined that it is ESJ, and the flow proceeds to step 101.
The 0-base counter 4 is incremented. As a result, 100
When you drive one meter, the reference value for the next 10 meters is changed to a new reference value corrected by taking into account the vehicle speed, and the count value of pulse counter 2 becomes equal to the new reference value. Steps are taken when When the vehicle continues to travel and the flow reaches step 106, the reference value used here is the uncorrected value.

Figure 6 shows how the mileage is corrected as the mileage increases. In the figure, it is assumed that the tire diameter does not change depending on the vehicle speed when traveling from 10 meters overnight to 100 meters. The distance is counted using the rounded value shown in Table 1 as the reference value, and the next time the vehicle travels 10 meters (distance 110 meters), the distance is counted using the new reference value corrected by taking into account the vehicle speed. , when the vehicle travels from 120 meters to 200 meters, the distance is counted again using the rounded values shown in Table 1 as reference values. In this way, in the shaded area in Figure 1, the previous mileage is corrected to a value that takes into account the vehicle speed, so the correct mileage is always displayed. Although the distance traveled has been corrected, this value may be arbitrary, and the time point at which the vehicle speed is detected may also be arbitrary.

〔Effect of the invention〕

As explained above, the mileage measuring method according to the present invention increments the odometer when the count value of the distance pulse reaches a predetermined reference value, and each time the odometer increments. , the reference value is updated, and each time the distance traveled reaches a predetermined value, the reference value at the time of the first step thereafter is corrected in accordance with the vehicle speed, so accurate driving is possible. This has the effect that distance can be measured and the distance traveled is not affected by changes in vehicle speed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the principle of this invention, FIG. 2 is a diagram showing the effects of this invention, FIG. 3 is a diagram showing standards for setting correction values, and FIG. 4 is a diagram showing this invention constructed by a microprocessor. , FIG. 5 is a 70-chart showing the operation of the apparatus shown in FIG. 4, and FIG. 6 is a diagram for explaining the state in which correction is performed. 1-- Distance sensor, 1b--Vehicle speed sensor, 2
...Pulse counter, 3...Comparator, 4...
・Decimal counter, 511.0・Reference value generator, 5m,
6h a...Correction Table 9 Patent Applicant Koito Manufacturing Co., Ltd. Agent Masaki Yamakawa (and 1 other person)

Claims (1)

[Claims] A pulse counter counts the distance pulses generated by the distance sensor every time you travel a predetermined distance, and when this count value corresponds to the value of the minimum unit digit of the odometer, the minimum unit digit of the odometer is displayed. In the mileage measurement method that steps the distance, the value obtained by adding 1 to the display value displayed in the minimum unit digit is divided by the mileage distance per distance per pulse, and then rounded to the nearest whole number, and the reference value and the pulse counter total. Each time the numbers become equal, the display of the minimum unit digit of the odometer is incremented, and each time the mileage reaches a predetermined value, a correction value corresponding to the vehicle speed at that time is calculated by a predetermined method, and the mileage is calculated. Immediately after reaching a predetermined value, only the reference value used when incrementing the minimum unit digit is changed to a value obtained by correcting the correction value to the reference value, and the display of the minimum unit digit is changed to zero. A mileage measuring method characterized by resetting a pulse counter when