JPH0234565Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in angle measuring devices such as theodolites.

Conventionally, as a device for measuring angles without using a scale, for example, the USARMY Engineer
Topographic Laboratories Report ETL−TR
There is something reported in -72-1.

This angle measuring device measures the time T1 required for a slit provided on the circumferential surface of a constant-velocity rotating body to rotate once relative to a fixed reference point, and the time required for the slit to rotate from that reference point to the angle measurement point. The time required for T2
The angle is determined by calculating 360 degrees x (T2/T1).

The angle measuring device as described above is characterized in that measurement is easy because it does not require a scale, and its configuration is also simple.

The report also mentions so-called 180-degree opposing readings to compensate for errors caused by eccentricity between the center of rotation of a constant-velocity rotating body and the center of rotation of an angle measurement point.

In the device described in the same report, the constant rotation performance of the rotating body in one rotation greatly affects its angle measurement accuracy. Therefore, in order to maintain high angle measurement accuracy, considerable care must be taken to ensure that the constant speed rotation performance of the motor that drives the rotating body does not fall below a predetermined value.

If there is one period of uneven rotation during one rotation of the rotating body, the negative effect tends to be canceled by adopting 180 degree opposing reading.
This is an additional advantage of 180 degree facing reading. by the way,
During one rotation of the above-mentioned rotating body, there are two or more periods of rotational unevenness, but regarding correction of these multiple periods of rotational unevenness, the report states:
Not mentioned.

The present invention was developed by focusing on the above-mentioned conventional problems, and with a simple configuration, it is possible to sufficiently correct the rotational irregularities of multiple periods that occur during one revolution of the rotating body, and Therefore, it is an object of the present invention to provide an angle measuring device that can maintain a high level of angle measurement accuracy even when using a motor with lower constant speed rotation performance than conventional motors.

To achieve this objective, the present invention consists of a constant velocity rotating body having a detected part, a collimating arm having a rotation center that is approximately the same as the rotation center of this constant velocity rotating body, and a reference provided on a fixed part. point, and an angle measurement point provided on the collimation arm, and the time T1 required for the detected part of the constant velocity rotating body to rotate once with respect to the reference point or the angle measurement point, and the reference point. Find the time T2 required to rotate between the point and the angle measurement point on the sighting arm, and calculate the angle amount equivalent to one rotation x
In an angle measuring device that calculates the angle between a reference point and an angle measurement point by calculating (T2/T1), a slit as a detected part is placed on a constant velocity rotating body at different positions in the circumferential direction. Provide 3 or more
One of the slits is provided for generating a measurement start signal in a manner that can be distinguished from the other slits, and after this measurement start signal generation slit passes a reference point or an angle measurement point, each slit connects the reference point and angle measurement point. The above T can be calculated by measuring the time required to pass between each point and averaging these measurements.
The feature is that it searches for 2.

The slit as a detected part on a constant speed rotating body is
It can be provided separately for the reference point and the angle measurement point, or it can be provided as a shared type.

In addition, the slit for generating the measurement start signal may be provided at the same radial position with a different width from other slits, or may be provided at a different radial position from other slits. can be distinguished.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings. FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view taken along the line - in FIG. 1.

The rotating body 1 is composed of two discs 1a and 1b, and is rotated at a constant speed by a motor 3 via a rotating shaft 1c, and the rotating shaft 1c is a non-movable part of the angle measuring device. It is pivotally supported by a certain board 2. The rotation axis of the collimating arm 4 is set to substantially coincide with the rotation axis 1c. A collimating telescope (not shown) is fixed to the collimating arm 4, so that the angle of the collimating telescope and the angle of the collimating arm 4 match.

Further, on the substrate 2, there is a reference point R as a reference.
1 and R2 are provided, and each of these reference points R1 and R2 has a pair of light emitting element and light receiving element. Furthermore, slits SR1, SR2, SR3, and SR4 are provided on the outer periphery of the disc 1b constituting the rotating body 1, and these slits SR1, SR2, SR3,
As the rotating body 1 rotates, the SR4 passes through an optical path from the light emitting element to the light receiving element forming the reference points R1 and R2. Then, when the rotating body 1 is rotating, the slit
When SR1, SR2, SR3, and SR4 pass through these optical paths, each light receiving element generates a pulse.

On the other hand, angle measurement points M1 and M2 are provided at both ends of the collimating arm 4. At these angle measurement points M1 and M2, a set of a light emitting element and a light receiving element is provided, respectively, similarly to the reference points R1 and R2. These light-emitting elements and light-receiving elements face each other with a disk 1a in between, and each time the slits SR1, SR2, SR3, and SR4 provided in the disk 1a pass through angle measurement points M1 and M2, the angle is measured. Point M1, M
A pulse is generated at 2. In this example,
These slits SR1, SR2, SR3, SR4
are slits SM1, SM2, SM3, respectively.
It is formed at the same radial and circumferential positions as SM4. Also, the angular interval is approximately 90°.

And among each 4 slits, SR1, SM1
is for outputting a measurement start signal, and in order to distinguish it from other slits, it is wider than the other slits in this embodiment. Conversely, the width may be narrower than other slits.

FIG. 3 shows an example of the circuit used in the above embodiment, and FIG. 4 is a time chart showing the signal waveforms of the main parts of FIG.

Here, to improve measurement accuracy, counter reading (for example, the time it takes for a certain slit to move from one reference point to the next angle measurement point, and the time it takes for a slit to move from the remaining reference points to the remaining angle measurement points) However, only one method will be explained below. That is, only R1 is used as the reference point, and M1 is used as the angle measurement point.
The following explanation assumes that only . The reference point R1 is
It is directed towards one target point, the angle of which is to be measured, and the angle measuring point M1 on the sighting arm 4 is directed towards the other target point. When performing facing reading, further check the reference point R2 and the angle measurement point M based on the following explanation.
After measuring 2 as well and performing predetermined calculations,
Just take the average of both.

In FIGS. 3 and 4, the R1 output signal is the output signal of the light receiving element at the reference point R1, and the symbols PR1, PR2, PR in FIG.
3.PR4 are slits SR1, SR2, and
This is a pulse generated when SR3 and SR4 pass the reference point R1. Also, in Figures 3 and 4,
What is indicated as M1 output signal is the angle measurement point M1.
These are the output signals of the light receiving elements in FIG. 4, and symbols PM1, PM2, PM3, and PM4 in FIG. 4 are pulses generated when the slits SM1, SM2, SM3, and SM4 respectively pass the angle measurement point M1. On the other hand, since the slit widths of slits SM1 and SR1 are so wide that they can be distinguished from other slits, the pulses PR1 and PM1 corresponding to the slit widths are
It is wider than other pulses.

The measurement start signals 11 and 12 are pulses PR1,
This is output from a microcomputer or the like immediately after PM1 occurs.

D flip-flops FF1 and FF2 turn R after measurement start signals 11 and 12 rise, respectively.
1, M1 output signal is frequency-divided by one stage. D
Flip-flops FF3 and FF4 divide the output signal of the previous stage by one stage after the measurement start signals 11 and 12 rise, respectively.

RS flip-flop FF5, FF6, FF7, FF
8 is set at the rising edge of each output signal of the D flip-flops FF1-FF4 processed by the AND circuits 51-82, and is reset at the rising edge of the same signal.

That is, the RS flip-flop FF5 outputs a pulse that becomes Hi between the first rise of the D flip-flop FF1 and the first rise of the D flip-flop FF2. The RS flip-flop FF6 outputs a pulse that becomes Hi between the first fall of the D flip-flop FF1 and the first fall of the D flip-flop FF2. RS flip-flop FF7 is active between the second rising edge of D flip-flop FF1 and the second rising edge of D flip-flop FF2.
Outputs a high pulse. The RS flip-flop FF8 outputs a pulse that becomes Hi between the second falling edge of the D flip-flop FF1 and the second falling edge of the D flip-flop FF2.

The reason why D flip-flops FF3 and FF4 are used here is as follows. In other words, by using these flip-flops FF3 and FF4, the rise and fall timings of the pulses they output are slightly delayed from the timing of their input pulses, and using this delay time, the AND circuits 51 to 82 This is to create trigger pulses for RS flip-flops FF5 to FF8.

The non-inverted output signals of the RS flip-flops FF5 to FF8 are ANDed with the clock pulse by AND circuits 53, 63, 73, and 83, respectively, and counted by counters 54, 64, 74, and 84. In other words, the shaded portions t5, t in FIG.
The time corresponding to the length of 6, t7, and t8 is counted by the clock. Then, a microcomputer (not shown) controls the counters 54, 64, 74, 84.
The contents of are read, their arithmetic average is taken, and the time is set as T2. That is, from the above time t5
t8 is a slit for outputting a measurement start signal.
This is the time required for each slit SR2 (SM2) to SR1 (SM1) to pass from the reference point R1 to the angle measurement point M1 after SR1 (SM1) passes the reference point R1, and these are averaged. Thus, it is possible to obtain an accurate T2 that is not affected by uneven rotation.

In addition, slit SR, including one for measurement start signal output,
If the number of SMs is three or more, the purpose of reducing the influence of uneven rotation of the rotating body 1 can be achieved. Theoretically, the more slits there are, the less the influence of rotational unevenness will be, but in practice, the influence of rotational unevenness can be sufficiently removed with 10 or less, for example, about 3 to 6 slits. Furthermore, although these do not necessarily have to be at equal angular intervals, equal angular intervals can more reliably eliminate the influence of uneven rotation.

On the other hand, the D flip-flop FF9 divides the non-inverted output of the D flip-flop FF3 by one stage, that is, divides the R1 output signal by two stages. Thereby, one rotation time T1 of the rotating body 1 can be obtained. This one rotation time T1 is determined by the counter 9
4 is obtained by counting the clocks.

Then, by performing the calculation of 360 degrees x (T2/T1), the angle measurement value at that time can be obtained.

Here, taking the average of the number of pulses counted by the counters 54, 64, 74, 84 means that in order to obtain the above T2, the rotating body 1 is moved from the reference point R1 to the angle measurement point M1. This means that the rotation time required for rotating the rotating body 1 is measured by changing the angular position of the rotating body 1 by 90 degrees, and the measured values are averaged. This will average out rotational unevenness. The rotational unevenness that can be corrected in this way is effective not only for one period of rotational unevenness but also for multiple periods of rotational unevenness.

In the above embodiment, the number of pairs of slits is four, but the number may be three or more.

On the other hand, in 180 degrees facing reading, reference point R2,
The above principle can be similarly applied to the angle measurement point M2, and four more pulses (corresponding to pulses having a width of time t5 to t8) can be obtained during one rotation of the rotating body 1. , a total of eight pulse widths are averaged.

The timing at which the measurement start signals 11 and 12 shown in FIGS. 3 and 4 are generated is important from the viewpoint of obtaining highly accurate angle measurement values. That is, the measurement start signals 11 and 12 must always be output in a constant relationship with respect to each pulse in the R1 output signal or the M1 output signal. In the above embodiment, the measurement start signals 11 and 12 are generated based on the slits SR1 and SM1. And since all the slits are provided on the disk,
Since the slits SR1 and SM1 are in a certain relationship with other slits, and the slits SR1 and SM1 are provided in such a manner that they can be distinguished from the other slits, the pulses PS1 and PM1 generated based on the slits SR1 and SM1 are is reliably detected, and therefore the timing of generation of measurement start signals 11 and 12 generated based on these pulses has a constant relationship with respect to other pulses.

It is easy to output the measurement start signals 11 and 12 at the above timing. That is, it can be realized by conventional techniques such as using hardware or microcomputer software such as determining the pulse width using an integrating circuit.

In addition, in the above embodiment, the slits SR1,
Although the pulse width of SM1 is made larger than that of the other slits, the present invention is not limited to this. For example, as shown in FIG. 5, on the disk 1a, the slits are placed on a track different from the track on which the slits SM2, SM3, and SM4 are arranged.
SM5 may be provided, and the slit SR5 may be provided on a track different from the track on which the slits SR2, SR3, and SR4 are provided on the disc 1b. In this case, those slits
In order to detect SM5 and SR5, it is necessary to provide a reference point R3 and an angle measurement point M3.

In this way, the pulses generated by the slits SM5 and SR5 can be reliably distinguished from the pulses generated by other slits, and these pulses can be used to control the measurement start signals 11 and 1.
2 can be appropriately generated.

Furthermore, in the above embodiment, the slit for the reference point R1 or R2, R3 and the slit for the angle measurement point M1, M2, M3 are provided separately, so when counting the slits, the concept of pairs can be avoided. It becomes necessary. However, the same slit can be used both as a reference point and as an angle measurement point, i.e.
If the slits provided in one disc are shared as the reference point and the angle measurement point, the concept of pairs of slits becomes unnecessary, and the number of slits becomes 1.
You can count one, two, etc. however,
In this case, there is an inconvenience that the collimating arm 4 cannot rotate once relative to the rotating body 1.

As mentioned above, mechanically, the present invention can prevent rotational irregularities within one rotation of the motor by providing three or more slits and setting one of the slits in a manner that allows it to be distinguished from the other slits. Therefore, even if a motor with low rotational performance is used, it is possible to perform highly accurate angle measurement.

[Brief explanation of the drawing]

Figure 1 is a plan view showing one embodiment of the present invention;
The figure is a longitudinal cross-sectional view taken from the - line in Figure 1, Figure 3 shows an example of the circuit used in the above embodiment, and Figure 4 is a timing diagram showing waveforms in the main parts of Figure 3. FIG. 5 is a plan view showing another embodiment of the present invention. 1... Rotating body, 1a, 1b... Disk, 2... Board, 3... Motor, 4... Collimation arm, FF1~
FF4, FF9...D flipflop, FF5~
FF8...RS flip-flop, 54, 64, 7
4, 84, 94...Counter, R1, R2, R3
...Reference points as detection points, M1, M2, M3...
...Angle measurement points as detection points, SR1, SR2,
SR3, SR4, SR5, SM1, SM2, SM3,
SM4, SM5...Slit as the detected part.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A constant-velocity rotating body having a detected part, a collimating arm having a rotation center that is substantially the same as the rotation center of the constant-velocity rotating body, and a reference provided on a fixed part. point, and an angle measurement point provided on the collimation arm, and the time T1 required for the detected part of the constant velocity rotating body to rotate once with respect to the reference point or the angle measurement point, and the reference point. Determine the time T2 required to rotate between the point and the angle measurement point on the sighting arm,
In an angle measuring device that calculates the amount of angle between a reference point and an angle measurement point by calculating the amount of angle corresponding to one rotation x (T2/T1), Three or more slits are provided at different positions in the circumferential direction, one of which is provided for generating a measurement start signal in a manner that can be distinguished from the other slits, and this slit for generating a measurement start signal is set at a reference point or at an angle. After passing the measurement point, the time required for each slit to pass between the reference point and the angle measurement point is measured, and by averaging these measurements, the detected part of the constant velocity rotating body can be determined. An angle measuring device characterized by determining the time T2 required to rotate between a reference point and an angle measuring point on a collimating arm. (2) In the angle measuring device set forth in claim 1 of the utility model registration claim, the slit serving as the detected portion on the constant velocity rotating body has an angle that is separately provided for the reference point and the angle measuring point. measuring device. (3) In the angle measuring device according to claim 1 of the utility model registration claim, the slit for generating a measurement start signal is provided at the same radial position with a different width from other slits. Angle measuring device. (4) Utility Model Registration The angle measuring device according to claim 1, wherein the slit for generating a measurement start signal is provided at a different radial position from the other slits.