JPH0432326B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a laser lighthouse that rotates and irradiates a laser beam in a horizontal plane at a reference point and irradiates two line-symmetrical beams, and a measurement point that detects the laser beam at a measurement point. A time measurement device that measures the time gap between laser beam reception, and a time measurement device that measures the time gap between laser beam reception, calculates the angle between the line symmetry axis and the measurement point from the laser beam reception time gap, and calculates that value and the angle between the reference line and the symmetry axis. The present invention relates to a laser lighthouse that is an angle detection device using a laser, and a coordinate calculation display device that calculates and displays the coordinates of a measurement point from the distance between reference points.

[Prior Art] The conventional method of determining a plane position or angle by triangulation is usually carried out using a transit, and when using a transit, it requires one surveyor operating the transit and a worker holding a pole. This required at least two people and was time consuming.

Therefore, the present applicant first filed a patent application for a device for surveying using a laser (patent application filed in 1983-
No. 267481). To explain this with reference to Figures 2 and 3, A and B are reference points, C is a measurement point, and reference point A is a symmetry axis that detects the direction of the symmetry axis of the laser lighthouse 1A and the other laser lighthouse 1B. A detection sensor 2A is installed, and a symmetry axis detection sensor 2B is installed at the reference point B to detect the direction of the axis of symmetry between the laser lighthouse 1B and the other laser lighthouse 1A, and at the measurement point C, the laser lighthouse 1A and the laser lighthouse A measurement point sensor 3 for detecting the laser beam 1B is installed, and the measurement point C is further provided with a time measurement device (light receiving gap measurement circuit) 4 and a coordinate calculation display device (microcomputer) 5. is the distance between reference point A and reference point B, and is measured in advance.

Laser lighthouses 1A and 1B emit two symmetrical laser beams in the counterclockwise and clockwise directions, respectively.
The coordinates of the measurement point C are determined from the angles θ and ψ formed by the sensor 3 and the lighthouses 1A and 1B and the distance when the measurement point sensor 3 receives the two laser beams simultaneously by rotating Lccw and Lcw. is calculated using trigonometry. In addition,
The symmetry axis detection sensors 2A and 2B are used to determine the reference directions of the reference points A and B. This device is an excellent surveying method because it allows rapid surveying without requiring special skill, and also enables automatic data recording and input into a computer.

By the way, in this laser lighthouse that rotates and irradiates two line-symmetrical beams at an even rotational speed, the amount of rotational jitter and rotational unevenness directly affects the measurement accuracy, and the degree of this is greater as the rotational speed is lower. .

[Problems to be Solved by the Invention] The present invention has been made to provide a laser lighthouse of an angle detection device with small rotational irregularities.

[Principle of the Invention] As a result of various studies, the present invention has found that the principle of gyroscope preset can be suitably applied to this type of laser lighthouse. This will be explained with reference to FIG. The basic form of the gyroscope is as shown in the figure, in which a rotor 10 rotating at high speed is held by a gimbal axis Y of a horizontal gimbal 11 and a gimbal axis Z of a vertical gimbal 12, which are perpendicular to each other and are perpendicular to its rotation axis X. In an ideal state (the dynamic balance of the rotor 10 and the static balance of each gimbal 11, 12 are perfectly maintained, and the air resistance is also
(all bearing friction is also zero), rotor 1
0 has the property of forever facing a fixed direction in space, that is, it has the rigidity of a gyroscope.

Furthermore, when force F is applied to point P on the rotor rotation axis X of horizontal gimbal 11, point P does not fall downward;
The horizontal gimbal 11 maintains its horizontal position and begins to rotate at a constant angular velocity around the gimbal axis Z of the vertical gimbal 12. Therefore, the gimbal axis Z is rotated by the horizontal gimbal 11, which is called preset. This is called the principle of perturbation or precession.

That is, the couple aF around the horizontal gimbal axis Y
(a is the distance between the axis Y and the point P), the horizontal gimbal 11 starts rotating around the vertical gimbal axis Z at an angular velocity Ω. In this case, aF=IωΩ where I=inertia factor of the rotor 10 and ω=rotational speed of the rotor 10. Solving the above equation for Ω, Ω=aF/Iω... (1) Here, when adding the couple aF by weight, aF is constant and I is also constant, so Ω is inversely proportional to ω. Therefore, the rotational unevenness of Ω is proportional to ω. What is needed in a laser lighthouse is the integral value of one cycle of rotational unevenness in Ω, and this error tends to be inversely proportional to the square of the rotational speed Ω. Therefore, it is more advantageous to have a higher rotational speed Ω, but due to other constraints, it is not possible to increase the rotational speed Ω unlimitedly. Therefore, (1)
Utilizing the property that the rotational unevenness of Ω in the equation is proportional to ω,
By controlling ω to be large and constant, rotational irregularities can be made extremely small even when Ω is at a relatively low speed.

[Structure of the Invention] The present invention has been made by applying the above-mentioned principle of gyroscope preset, and according to the present invention, a laser beam is rotated and irradiated in a horizontal plane at a reference point to irradiate two line-symmetrical beams. A laser angle detection device that uses a laser, consisting of a lighthouse, a measurement point sensor that detects laser light at the measurement point, a time measurement device that measures the time gap for receiving laser light, and a set of angle calculation and display devices. In a lighthouse, a laser oscillator, a rotating table that divides the laser beam from the laser oscillator into one direction and a direction opposite to the one direction, and a fixed mirror that flips the laser beam divided into the opposite directions by 180 degrees. The rotating shaft of the rotating table is coupled to the vertical gimbal axis of the gyro, and a preset weight is provided at one of the intersections of the horizontal gimbal and the rotating shaft of the gyro rotor.

[Operations and Effects of the Invention] Therefore, a couple force is applied to the gyro by the preset weight, and the rotary table is rotated with small rotational unevenness by the vertical gimbal axis rotated by the horizontal gimbal according to the principle of preset, and as a result,
Measurement accuracy can be improved.

[Preferred Embodiment] In carrying out the present invention, it is preferable that the gyro rotor is driven by a speed-controlled motor, and that electric power is supplied to the motor, for example, via a slip ring. In this way, the rotational unevenness of the vertical gimbal shaft of the gyro is proportional to the rotational speed of the gyro rotor, so that even if the rotating table is rotated at a relatively low speed, the rotational unevenness can be reduced.

[Examples] Examples of the present invention will be described below with reference to the drawings.

In FIG. 1, the laser lighthouse shown as a whole by 20 has an upper part 21a closed in one horizontal direction and a lower part 21a closed in one horizontal direction.
A base 21 with bb open on both sides in the direction perpendicular to the plane of the paper in the horizontal direction, a laser oscillator 22 that is vertically installed on the upper part 21 and oscillates a laser beam L1 downward from a collimator lens 22a, and a fixed mirror to be described later. A prism 23 is integrally coupled to the lower surface of the laser oscillator 24 and inverts the laser beam L1 from the laser oscillator 22 twice at right angles and irradiates it in the vertical axis Z direction, and a rotating table 25 provided on the inner upper surface of the upper portion 21a and described later.
The laser beam L5 from the prism 28 of
A fixed mirror 24 that is rotated and irradiated as a horizontal laser beam Lcw, a rotating table 25 that is rotated counterclockwise around the vertical axis Z of the base 21, and a prism 23 that is provided on the axis of the rotating table 25. a pentaprism 26 that inverts the laser beam L from the penta prism 26 twice and irradiates it in the horizontal direction; laser light
A beam splitter 27 separates the laser beam L4 perpendicularly upward to Lccw, and the laser beam L4 is integrally coupled to the upper surface of the beam splitter 26.
It consists of a prism 28 that inverts the light beam 4 at right angles and illuminates the fixed mirror 24, and a well-known gyroscope 30, generally indicated by 30, provided inside the lower part 21b.

The vertical gimbal 31 of the gyro 30 has a vertical axis Z
Bearings 33,
The gimbal shaft 32 a is rotatably supported by the base 21 via the gimbal shaft 33 , and the gimbal shaft 32 a is coupled to the rotary base 25 .
That is, the rotating shaft of the rotating table 25 is coupled to the gimbal shaft 32. The horizontal gimbal 34 is rotatably supported by the vertical gimbal 31 via bearings 35, 35 by gimbal shafts 34a, 34b. The gyro rotor 36 has rotor rotation shafts 37a and 37b.
(37b is not shown) bearings 38, 38
(one 38 is not shown) is rotatably supported by a horizontal gimbal 34, and a preset weight 39 is attached below one bearing 38 of the horizontal gimbal 34. The gyro rotor 36 is driven by a speed-controlled motor (not shown) to rotate at high speed at an angular velocity ω, and electric power is supplied to the motor via a slip ring (not shown).

During operation, the horizontal gimbal 34 uses a preset weight 39 to create the couple shown in FIG.
Since aF is acting, the horizontal gimbal 34 moves vertical gimbal axes 32a and 3 according to the preset principle.
2b at an angular velocity Ω, thereby causing the vertical gimbal shafts 32a, 32b to rotate at an angular velocity Ω with small rotational irregularities. Note that this rotational unevenness is proportional to the high rotational speed ω of the gyro rotor 36 as shown in equation (1), so it is extremely small even if the rotational speed Ω is relatively low.

On the other hand, the laser beam L from the laser oscillator 22
1 is split into a counterclockwise rotating laser beam Lccw and a laser beam L4 by a beam splitter 27 of a rotating table 25 rotating counterclockwise.
One of the laser beams L4 is inverted twice at a right angle by a fixed prism 25, and is irradiated from the laser lighthouse 20 as a clockwise rotating laser beam Lcw. These laser beams Lccw and Lcw are
5, the laser beam is irradiated from the laser lighthouse 20 with a small rotational unevenness. As a result, measurement accuracy is improved.

[Summary] As explained above, according to the present invention, horizontal laser beams are irradiated in the counterclockwise and clockwise directions by a rotary table rotated by the principle of gyro preset at a rotation speed with small rotational unevenness, and as a result, Measurement accuracy can be improved.

[Brief explanation of drawings]

Fig. 1 is a side sectional view showing an embodiment of the present invention, Figs. 2 and 3 are a plan view and side view illustrating an angle detection device using a laser beam, and Fig. 4 is an illustration of the principle of presetting the gyro. It is a perspective view of a gyroscope. Lccw……Laser light rotating counterclockwise, Lcw
. . . Clockwise rotating laser beam, 22 . . . Laser oscillator, 24 . . . Fixed mirror, 25 .
...Vertical gimbal axis, 34...Horizontal gimbal, 36
... Gyr rotor, 37a, 37b ... Rotor rotation axis, 39 ... Weight for preset.

Claims (1)

[Claims] 1 A laser lighthouse that rotates a laser beam in a horizontal plane at a reference point and emits two line-symmetrical beams, a measurement point sensor that detects laser light at a measurement point, and a time measurement that measures the time gap between receiving laser light. In a laser lighthouse of an angle detection device using a laser, the laser lighthouse includes a laser oscillator and a laser oscillator, and a laser beam from the laser oscillator is divided into one direction and a direction opposite to the one direction. A rotary table and a fixed mirror for reversing the laser beams divided into opposing directions by 180 degrees are provided, and the rotation axis of the rotary table is coupled to the vertical gimbal axis of the gyro, and the horizontal gimbal and the rotation axis of the gyro rotor are connected. A laser lighthouse of an angle detection device, characterized in that a weight for presetting is provided on either one of the intersection points.