JPH03186765A - Speed-of-revolution measuring device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a counting means for counting the number of times a rotating body rotates by a unit angle, a clocking means, a count value of the counting means, and clock information of the clocking means. The present invention relates to a rotation speed measuring device provided with calculation means for calculating the rotation speed per unit time every time a set time elapses based on the following.

[Conventional technology]

This type of rotational speed measurement device described above is used, for example, as a means for repeatedly measuring the engine rotational speed at set time intervals in order to determine the load state of the engine.

By the way, when measuring the number of rotations, it is necessary to remove the effects of uneven rotation, etc., so conventionally, the counting time for the number of rotations of a rotating body per unit angle is increased to improve measurement accuracy. Ta.

[Problem to be solved by the invention]

However, in order to increase the measurement accuracy, the time interval required for rotational speed measurement becomes longer, which has the disadvantage of delaying response to rapid rotational speed fluctuations.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to make it possible to detect even rapid fluctuations in the rotational speed without reducing the measurement accuracy of the rotational speed.

[Means to solve the problem]

The rotation speed measuring device according to the present invention includes a counting means for counting the number of times a rotating body rotates by a unit angle, a clocking means, and a set time elapsed based on a count value of the counting means and clock information of the clocking means. The apparatus is provided with arithmetic means for calculating the number of rotations per unit time each time the rotation is performed, and its characteristic configuration is as follows.

That is, the calculation means calculates the calculation result at the time when the set time has elapsed based on the amount of increase in the counted value of the counting means from the previous measurement time when the rotation speed was calculated to the present time and the elapsed time from the previous measurement time. The change in the predicted value is determined by repeatedly calculating a child measured value of the rotational speed and determining whether the amount of change in the predicted value with respect to the rotational speed at the time of the previous measurement is greater than a set value. If it is determined that the amount is greater than the set value,
The present invention is configured to use the predicted value as the current rotational speed.

[For production]

In other words, while the set time has elapsed from the previous measurement until the current measurement, the child measurement value of the rotation speed at the time when the set time has elapsed is calculated, and the amount of change in the predicted value for the rotation speed at the previous measurement is set. By repeatedly determining whether or not the speed is high based on the value, the presence or absence of a sudden change in the rotational speed is checked. If the amount of change in the predicted value is greater than the set value, the predicted value is measured as the current rotational speed.

〔Effect of the invention〕

Therefore, while the set time required to measure the rotation speed has elapsed, sub-measurement values of the rotation speed are obtained and the amount of change from the previous measurement is repeatedly checked, so the settings required for measurement are made to improve measurement accuracy. Even if the time is increased, it is possible to respond to sudden changes in the rotational speed with little response delay.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, an embodiment in which the present invention is applied to an engine rotation speed measuring device will be described based on the drawings.

As shown in Fig. 1, an encoder (2) that outputs a pulse signal every time the output shaft (1) rotates a unit angle is provided on the output shaft (1) of the engine (E) as a rotating body. , a controller (3) is provided that executes processing for measuring the number of revolutions per unit time (ENG) based on the output information of the encoder (2).

The controller (3) is configured using, for example, a microcomputer, and includes a counting means (100) for counting the output of the encoder (2), that is, the number of times the rotating body has rotated by a unit angle, and a timer. Means (101)
, and their counting means (100) and timekeeping means (101)
) is configured to determine the rotational speed (ENG).

However, the counting means (100) is configured as a so-called software counter, and as shown in FIG. 3, each time one pulse signal output from the encoder (2) is input, Add the counted value (REV)
This is implemented as an interrupt process that is activated every time the pulse signal is input so as to add one.

As will be described later, the time measuring means (101) is also configured as a software counter, and the reference time (101) is configured as a software counter.
This is implemented as a process of adding +1 to the count value, ie, the elapsed time (CNT), each time Xo ) elapses.

Next, the configuration of each of the above means will be explained in detail based on the flowchart shown in FIG.

When the control operation is started, first, the reference time (Xo)
It is determined whether or not the period has elapsed, and if the period has not elapsed, no processing is performed.

As the reference time (XO) elapses, the time measuring means (
101), the elapsed time (CNT) is calculated as the rotation speed (E
It is determined whether or not the time has exceeded the set time (x) which is the reference measurement period for NG).

When the elapsed time (CNT) is greater than the set time (X), the count value (RE
After outputting V) as the rotational speed (ENG), the count value (REV) and the elapsed time (CNT) are reset to zero, and the current measurement is completed.

If the elapsed time (CNT) is not greater than the set time (X), the amount of increase in the count value of the counting means (100) from the previous measurement time when the rotation speed was calculated to the present time, that is, the count value ( Based on the current value of REV) and the elapsed time (CNT) from the previous measurement time, the predicted value of the rotational speed (ENG) at the time when the set time (x) has elapsed, as shown in the formula below. (RRE
Find V).

RREV= REV X x/ CN7 Next, the predicted value (R
It is determined whether there is a sudden change in the rotational speed by determining whether or not the amount of change in the rotation speed (REV) is a dog based on a preset value (I).

If the amount of change in the predicted value (RREV) is greater than the set value (I), it is determined that there is a sudden change in the rotation speed, and the system is designed to prevent a delay in response to the sudden change in rotation speed. In order to do this, after outputting the predicted value (RREV) as the current rotational speed (ENG),
The current measurement is ended by resetting the values of EV) and elapsed time (CNT) to zero, respectively.

If the amount of change in the predicted value (RREV) is not greater than the set value (I), the process ends without processing.

[Another example]

In the above embodiment, the counting means (100) and the timer stage (1
01) are configured as software counters, but they may also be configured as so-called hardware using counters, timers, etc., for example.

Furthermore, in the above embodiment, each time a measurement is performed, the count value (REV
) and elapsed time (CNT) are reset to zero, but the count value (REV) and elapsed time (CNT) are reset to zero.
CNT) repeats the integration from the time of startup,
The value of the difference between the previous readout and the current readout may be used. Furthermore, the present invention can be applied to various rotational speed measuring devices for measuring the rotational speed per unit time of various rotating bodies in addition to the engine rotational speed, and the specific configuration of each part can be modified in various ways. can.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the rotational speed measuring device according to the present invention, in which FIG. 1 is a block diagram, FIG. 2 is a flowchart of control operation, and FIG. 3 is a flowchart of counting processing. (x)...Setting time, (CNT)...
Elapsed time, (ENG)...Rotation speed, (REV)
...Count value, (RREV) ...Predicted value, (I) ...Setting value, (1) ...Rotating body, (100) ... ...Counting means, (101)...
...Timekeeping means, (102) ...Calculation means.

Claims (1)

[Claims] A counting means (100) for counting the number of unit angle rotations of the rotating body (1), a clocking means (101), a count value (REV) of the counting means (100), and a clocking means (10).
1) and a calculation means (102) for calculating the number of revolutions per unit time (ENG) every time a set time (x) elapses based on the timekeeping information of the above-mentioned. The calculation means (102) calculates the number of revolutions from the previous measurement time to the present time.
0) and the elapsed time (CNT) from the previous measurement time, the predicted value (RREV) of the rotation speed (ENG) at the time when the set time (x) has elapsed.
), and repeatedly determining whether the amount of change in the predicted value (RREV) with respect to the rotation speed (ENG) at the time of the previous measurement is greater than the set value (I), If it is determined that the amount of change in the predicted value (RREV) is greater than the set value (I), the rotation is configured to make the predicted value (RREV) the current rotational speed (ENG). Counting device.