JPH06300564A - Angle measurement method - Google Patents

Abstract

PURPOSE:To develop, apply and expand a precision measurement method for an angle as a basis of a survey, etc. CONSTITUTION:The passage time of a turning electromagnetic wave beam is measured at two measurement points, and an angle theta between the two measurement points with an apex taken at the center of the beam is obtained from a ratio of the passage time (t) and the cycle T of the beam, using an equation theta=2pit/T (rad). Also, this angle measurement method is applied for expansion to a trigonometrical survey, a range finder, an automatic survey or a navigation system.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to surveying used for civil engineering, construction, geography, and the like. Specifically, it relates to high-precision angle measurement (hereinafter simply referred to as angle measurement), which is the basis of surveying,
A novel method for increasing the accuracy and precision of the angle measurement is provided. In addition to surveying, it relates to a high-precision angle measuring method that can be applied to many fields such as specifying / instructing the position of ships, aircraft, vehicles (hereinafter abbreviated as a navigation system), measuring the displacement of the earth's core, etc. .

[0002]

2. Description of the Related Art Angle measuring instruments have long been used as basic instruments for surveying and the like, and compasses, clinometers, sextants, transits, theodolites, etc. have been used. In particular, the theodolite, which has been developed in recent years to read an angle by an electric method, has become popular as an electronic theodolite. However, in both cases, the target level and the reflector are captured by the telescope, and the angle of the optical axis of the telescope is read only optically or electrically by the angle scale or pattern scale, and the accuracy and precision of the angle measurement is limited. There is. The minimum reading is about 1 to 10 seconds (1 to 10 /
(360 × 60 × 60) ≈10 ⁻⁵ to 10 ⁻⁶ ), the number of effective digits for measurement is about 5 to 6 digits, and the accuracy is even worse.

A distance measuring device used for surveying is a standard scale,
There are tape measures, optical rangefinders, and radio rangefinders. In particular, optical rangefinders and radio rangefinders have advanced and become popular. However, the measurement is based on the propagation velocity of the electromagnetic wave and its round-trip time (often detected by an interference method), and changes in the propagation velocity due to the temperature, pressure, and humidity of the atmosphere, as well as on the ground by radio waves. Multiple propagation of the ionosphere affects,
For this reason, it is necessary to perform these corrections in precise measurement, but this is difficult, and the measurement error is a fixed error of 2 to 5 mm.
In addition, it is said that the value is equal to or more than a value obtained by adding an error of 2 to 5 ppm of the propagation velocity and the like. (The number of effective digits for measurement is 4 to 5 digits)

[0004]

In surveying in recent years, there is a great need for measurement with higher accuracy and precision (hereinafter abbreviated as high precision measurement). For example, map, geographic refinement, earthquake prediction by precise measurement of earth core displacement, land map refinement,
This includes precision and simplification of the navigation system. In other words, the development of a high-precision measurement method that replaces the conventional method is awaited,
The development of this basic angle measurement method is particularly awaited, and the development of this angle measurement method is an issue.

[0005]

[Means for Solving the Problems] In recent surveys, it is necessary to measure with higher accuracy and precision. ・ Among the measurement methods, high accuracy and precision are established by counting time, mass, and wave number. It is easy to measure the number of effective digits of 6 to 10 digits. In the present invention, it is applied to measure the angle by measuring the time (or counting the wave number),
This high precision is achieved. The method will be described with reference to the principle diagram of FIG. The service time of the electromagnetic wave beam that swirls (hereinafter abbreviated as swirl beam) is measured at two measurement points a. The angle θ between the two measurement points at the apex of the center point of the swirling beam is obtained from the ratio of the passing time t and the period T of the swirling beam, which is measured in step b. It can be expressed by the following equation. Angle θ = 2πt / T [rad] ···· (1) Formula = 360t / T [°] ······ (2) Formula

[0006]

The period T of one round of the swirling beam rotating at a uniform speed corresponds to the angle 2π rad (= 360 °).
The passing time t of the swirling beam at two measurement points on the plane drawn by the swirling beam corresponds to the angle θ between the two measurement points at which the center point of the swirling beam is apex. That is,
The expressions (1) and (2) are established, and the angle θ is obtained by measuring the passing time t and the cycle T at two measurement points.

It is desirable that the swirling beam be as narrow and narrow as possible, but the spread to a plane perpendicular to the swiveling plane is acceptable for this measurement. Rather, if you use this fan-shaped beam that is positively spread in the right angle direction,
The angle θ ′ between the two measurement points projected on the plane drawn by the swirling beam is obtained by the above-mentioned method. In other words, if the rotation of the swivel beam is made into a horizontal swivel plane using a level or the like, the angle θ _H projected on the horizontal plane necessary for surveying two arbitrary measurement points can be easily obtained. Similarly, if a vertical turning plane is used, the angle θ _V projected on the vertical plane required for surveying can be easily obtained.

Light, radio waves, X-rays, etc. are used as the electromagnetic wave beam. In particular, since the output light of the laser oscillator is a strong light beam with little diffusion, it is preferable for the light source of the swirling beam of the present application. Among surveying instruments, there is a laser planer using this light source, and a model that horizontally and vertically swirls a laser beam is commercially available, and its mechanism can be used in the method of the present application.

The following two items are important items related to the accuracy of the angle measuring method of the present application. (1) Uniformity of angular velocity of swirling beam (2) Accuracy of time measurement of period T of swirling beam and passage time t The swirling beam has a uniform angular velocity of rotation as much as possible and a constant center of swirling. The position can be confirmed with. Regarding the uniformity of angular velocity, in addition to the fact that the rotational moments of the light-emitting rotating body are evenly distributed, the bearings of rotating devices on the earth have a great influence, and the gyro compass and L
The rotating part of the P record is used as a reference to improve the uniformity. In this application, the absolute value measurement of the angular velocity of rotation is not necessary. This means that the cycle T of rotation is tested with an absolute value of an angle of 360 ° for each rotation. Therefore, strictly speaking, it is only required to be uniform during one round, and the uniformity is 10
The unevenness can be about ^-5 to 10 ^-10 . In space, the rotation of artificial satellites, the rotation of the earth and stars, orbits, and the rotation of double stars can be used. Measurement of period T and transit time t (to be exact, t /
The accuracy of the T ratio measurement) depends on the width of the swirling beam (or the shadow beam lacking the signal) and the switching sensitivity and reproducibility of the timing device. In order to improve the accuracy, the swirling beam and the timekeeping device system are subjected to high frequency modulation, the period T and the passage time t are measured by a wave number counter, and the count number N (= period T) and n (= passing time t ) Ratio n
/ T is calculated, and the angle is calculated by the following equation. Angle e = 2πn / N [rad] Equation (3) = 360n / N [degree] Equation (4) If the frequency of frequency modulation is set to about 10 GHz, the number of effective digits is 6 Measurement of 10 digits is easy. If multiple high frequency modulations are performed, the switching accuracy at the time measurement can be improved.
In the measurement of the present application, since the measurement value is obtained for each turning of the beam, repeated measurement is easy, and the accuracy of repeated measurement is easily improved. Most conventional angle measuring devices use visual observation with a telescope as a basic operation. However, in addition to human error and difficulty in automation, it is necessary to increase the resolution with a large-diameter lens to improve accuracy, and the cost is sharp. There are drawbacks such as up. On the other hand, according to the method of the present application, an angle-measuring device without a telescope can be manufactured, resolution of long distance is not deteriorated, and errors related to humans can be reduced, automation, efficiency, and cost reduction can be achieved.

In the triangulation method, it is fundamental to first precisely measure the angles between the triangular points. In the present application, the center point of the electromagnetic wave beam that swirls is placed on the triangular point, the transit time of the beam is measured on the other two points, the angle is calculated by the method described above, and the angle between the triangular points is sequentially obtained. It should be noted that it is possible to use one turning beam and two receivers to move between each triangular point for measurement, but if three sets of combinations of turning beam and receiver are placed on each point The angle between the triangle points can be found, and automation is easy. Next, as for the distance between the triangular points, when the angle between the three points is obtained, the distance between the three points is obtained by the normal triangulation calculation method with the two points of the triangular points as the reference length. From the measured values of the period T and the passage time t of each triangular point, the distance between the triangular points can be directly obtained with the distance between the two triangular points as the reference length. As an application of this, for example, the receivers a and b are provided in binoculars,
When observing a swirling beam (for example, a lighthouse), a distance meter can be obtained in which the radius (= distance) of the swirling beam can be obtained by using the length between a and b as a reference length, which is applied to a distance meter for ships and the like.

For precise measurement of displacement of the earth's core, for example, if a swirling beam is constantly emitted at three observation points on the summit and continuous observation is performed at each observation point, relative displacement between the three points can be detected, and earthquake prediction, etc. Be useful. In addition, if the orbiting beam source is installed in meteorological radars or lighthouses installed all over the country and measurements are taken between them, nationwide observation is possible. In this case, it will be necessary to improve the radio beam or the light beam of the lighthouse.

The navigation system can be applied by applying the above-mentioned method of precisely measuring the displacement of the earth's core, and its own position can be obtained by observing two or more fixed-point turning beams (lighthouse, electric lighthouse, etc.). If the fixed point is an artificial satellite, a wide and simple navigation system will be possible. Life buoys and satellites,
If a turning beam transmitter is attached to an aircraft, ship, vehicle, etc., its position can be continuously tracked, and its systemization is easy.

[0013]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1 An angle measurement experiment was conducted. The measuring instrument consists of a swing beam emitter, a light receiver and a time measuring device. The orbiting beam emitter has a right-angle prism placed on the rotary shaft of a 1-rpm synchro motor with a speed reducer with the rotary axis oriented vertically, and the optical laser beam (a red laser hand-held indicator for slide projection equipment is fixed from above this prism. It was used as a device to emit a swirling beam that rotates in a substantially horizontal direction. Two photocells a and b with slits each having a width of about 0.5 mm were used as the light receivers. For the time measuring device, the output of the photocell was recorded on a 2-pen mV recorder, and the length on the chart was measured with a loupe and a digital caliper. In the experiment, the photocell a was fixed on the optical path of the swirling beam,
b is a triangle ruler from 30, 60, 90, 180
Moved to each angle of degrees, and its period T and ab
Measure the length on the chart that corresponds to the transit time between,
The angle was calculated by using the formula (4). The results are shown in Table 1.
Shown in. Even with a simple device, the angle can be easily obtained, and it is presumed that better results can be obtained by replacing the time measuring device with a highly accurate device. In the experiment, the beam was swung by a motor of 1 rpm, but it is preferable that the beam is swiveled in a practical device.

Example 2 An experiment was carried out with the same apparatus as in Example 1 except that a commercially available laser planer (laser leveler or the like) was used as the orbiting beam emitter. As a result, the angle between a and b projected on the horizontal plane and the vertical plane could be measured. However, if an angle measuring method is established, this application and development can be easily carried out as described above, and therefore the application example will be omitted.

[0016]

The effects of the present invention described above will be listed below. ○ The principle of angle measurement is simple, and a relatively simple device (swivel beam emitter, receiver and time measuring device) enables precise angle measurement and provides a method that is easy to automate. ○ If the swivel plane of the swirl beam is horizontal or vertical, the angle of the measurement point projected on that plane is obtained, which is convenient for surveying. ○ When applied to rangefinders, precision rangefinders that do not require propagation velocity correction such as weather conditions, which is a drawback of conventional lightwave rangefinders and radio rangefinders, can be made. ○ Most of the current survey instruments, such as theodolite and total station, are equipped with a telescope, which allows the angle and distance to be determined by visually observing the target staff and reflector. For this reason, there is a problem that the resolution in the distance decreases and the error increases due to individual differences, and further automation is difficult, but the method of the present application does not require this telescope, and it can be changed to a target staff or reflector. Operation such as placing a receiver,
An automatic surveying instrument system with almost no human error can be created. -Precision automatic measurement of angles is possible, and its application fields are wide, and it can be applied to continuous measurement of earth movements, navigation systems, tracking systems of moving objects, etc. in addition to surveying, and contributes to the societal needs of society. Is big.

[Brief description of drawings]

FIG. 1 is a plan view showing an implementation principle of the invention.

[Explanation of Codes] ', circling electromagnetic wave beam central point of circling electromagnetic wave beam a receiver a b receiver b T period of circling electromagnetic wave beam t t transit time between ab of circling electromagnetic wave beam θ angle

Claims (3)

[Claims] 1. A transit time of a swirling electromagnetic wave beam is measured at two measuring points, and from the ratio of the transit time to the period of the swirling beam, a measuring point between the two measuring points apex of the central point of the swirling electromagnetic wave beam. Angle measurement method characterized by finding the angle of. 2. The passing time at two measurement points is measured by using a fan-shaped electromagnetic wave beam which is expanded to a plane perpendicular to the plane of rotation, and the swirl beam is drawn by the method according to claim 1. An angle measuring method characterized by obtaining an angle between two measurement points projected on a plane. 3. In the triangulation method, the center point of the electromagnetic wave beam that swirls is placed on a triangular point, and the transit time of the beam is measured on the other two points. A surveying method characterized in that the angle between each triangular point is obtained by the method, and the distance between each point is obtained with the two points of the triangular points as a reference length.