JP3387964B2 - Automatic tracking surveying instrument - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention irradiates an object with the scanning light which is deflected by a light deflecting element to form scanning light, receives the scanning light reflected by the object, and surveys the object. The present invention relates to an automatic tracking surveying instrument that automatically tracks the body of the machine.

[0002]

2. Description of the Related Art Conventionally, scanning light is directed toward a space in which an object such as a prism is present, the scanning light reflected by the object is received, and the position of the object is detected. There is known an automatic tracking type surveying instrument that calculates tracking data by performing calculation based on the above and automatically tracks the surveying instrument main body to the object.

In this automatic tracking surveying instrument, a laser beam emitted from a laser diode is deflected by an acoustooptic device to obtain a scanning beam. The acousto-optic element is for making an ultrasonic wave incident and deflecting a laser beam according to the frequency of the ultrasonic wave.

[0004]

The deflection angle dθ of the laser beam by this acousto-optical element is determined by the following equation.

Dθ = λ × f / V where λ is the wavelength of the laser beam, f is the frequency of the ultrasonic wave,
V is the speed of sound in the crystal of the acousto-optic device.

This sound velocity V changes depending on the temperature inside the crystal (for example, in the case of a single crystal of TeO ₂ 211 × 10 ⁻⁶ m / degree C), and the wavelength λ of the laser light is also as shown in FIG. Changes with the temperature of the laser diode (FIG. 10 shows the relationship between the case temperature of the laser diode and the oscillation wavelength). Therefore, the deflection angle dθ differs depending on the temperature change.

To detect the position of the object, as shown in FIG. 11, the scanning area K in which the object is scanned is sequentially scanned from the top until the reflected light from the object M is received. Based on the number N of the lines S and the time t from the start of scanning of the scanning line Sn to the reception of the reflected light at the time of receiving the reflected light, the position of the object M with reference to the point P1 is obtained,
Further, the angles in the horizontal and vertical directions from the center P0 of the scanning region K, which is the optical axis, to the object M are obtained from the obtained position. Then, the main body of the surveying instrument is rotated in the horizontal direction and the vertical direction by the determined angle, and the center P0 and the object M are rotated.
Match with.

By the way, since the laser light is offset and input to the acousto-optic device, when the deflection angle dθ of the laser light changes due to a change in high temperature, the range of the scanning region K changes. For example, the deflection angle d of the laser light
As θ increases, the scanning area K ′ is displaced as shown by the chain line in FIG. Therefore, the number N ′ of scanning lines S ′ until the reflected light is received is different from N. Further, the time t'from the start of scanning the scanning line Sn 'to the reception of the reflected light at the time of receiving the reflected light also differs from t.

That is, the position of the object M based on P1 is different from the position of M based on P1 '. As a result, the angles in the horizontal direction and the vertical direction from the center P0 to the object M differ depending on whether P1 is used as a reference or P1 'is used as a reference.

Therefore, even if the surveying instrument main body is rotated in the horizontal direction and the vertical direction by the determined angle, depending on the temperatures of the laser diode and the acousto-optic element, the center P
There may be a case where 0 and the object M do not match. In other words, if the surveying instrument is used in a place where the temperature is largely deviated from the normal temperature, accurate tracking cannot be performed accurately.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an automatic tracking type surveying instrument which can always automatically and accurately track regardless of the environmental temperature.

[0012]

In order to achieve the above-mentioned object, the present invention deflects the light emitted from a light emitting element by a light deflecting element into scanning light, and irradiates the object with this scanning light. , by receiving the scanning beam reflected by the object to detect the position of the object, before on the basis of the detection result
In an automatic tracking type surveying instrument that automatically tracks the surveying instrument main body to an object to be recorded, the light emitting element and the light deflecting element have the same temperature.
Place on a large single substrate of thermally conductive so that as one, and the temperature detection means for detecting the temperature of the substrate, on the basis of a detection signal which the temperature detecting means detects the front due to the temperature change
A correction means for correcting a change in the deflection angle of the light of the light deflection element is provided.

[0013]

According to the present invention, the temperature detecting means determines the temperature of the substrate.
Based on the detected signal of the detected temperature detecting means.
The correction means corrects the change in the deflection angle of the light of the light deflection element.
Therefore, it always tracks accurately regardless of the ambient temperature.
be able to. Moreover, it is possible to generate on the same substrate with high heat conduction.
Light is emitted because the optical element and the light deflection element are arranged.
The temperature detection means for detecting the temperature of the element and the light deflection element is
Only one is required, and it is possible to suppress an increase in the number of parts.
Becomes cheaper.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an automatic tracking surveying instrument according to the present invention will be described below with reference to the drawings.

1 to 3, 1 is a survey table, 2
Is a corner cube as an object to be installed at a measuring point. The corner cube 2 is automatically tracked to this survey table 1.
An automatic tracking type surveying instrument 3 for measuring the distance to is installed.

The automatic tracking type surveying instrument 3 includes a base 4 and a mount 5
And a suspension unit 6. The gantry unit 5 is rotated with respect to the base 4 in the horizontal plane direction indicated by the arrow A. The cradle part 5 is the cradle part 6
Have. A rotation shaft 7 extending in the horizontal direction is provided on the frame portion 6, and a lens barrel portion 8 as a surveying instrument main body is provided on the rotation shaft 7. The lens barrel portion 8 is rotated in the horizontal direction by the rotation of the gantry portion 5, and is also rotated in the vertical direction by the arrow B by the rotation of the rotation shaft 7.

The lens barrel 8 has a distance measuring optical system 9 and a scanning optical system 1.
0 and are provided. The distance measuring optical system 9 has a light projecting unit 11 and a light receiving unit 12, as schematically shown in FIG. Projector 11
Has a light source 13. The light receiving section 12 has a light receiving element 14. The light source 13 emits an infrared laser beam. The infrared laser beam is reflected by the dichroic mirror 16 of the beam splitter 15 toward the objective lens 17, and is emitted as a parallel beam from the lens barrel 8 via the cover glass 18. The infrared laser beam is reflected by the corner cube 2 and passes through the cover glass 18 and the objective lens 17
Then, the light is reflected by the dichroic mirror 19 of the beam splitter 15 and focused on the light receiving element 14.

The received light output of the light receiving element 14 is input to the arithmetic unit of the control device CPU shown in FIG. Control device CP
U calculates the distance to the corner cube 2 based on the light receiving output of the light receiving element 14. Reference numeral 70 denotes a light emission deflecting unit that generates laser light and deflects the laser light into scanning light.

As shown in FIG. 4, the distance measuring optical system 9 has an image forming lens 20 and a reticle plate 21, and visible light passes through the objective lens 17 and the dichroic mirrors 16 and 19 to form the image forming lens 20. And converged on the reticle plate 21,
The measurer can visually recognize the measurement points including the corner cube 2 through the eyepiece lens 22.

The scanning optical system 10 includes a laser diode (light emitting element) 23 and a collimator lens 2 as shown in FIG.
4, a horizontal deflection element 25, a vertical deflection element 26, reflection prisms 27, 28 and 29, an objective lens 30, a cover glass 18, a reflection prism 32, a noise light removing filter 33, and a light receiving element 34. Laser diode 2
3, collimator lens 24, horizontal deflection element 25,
Vertical deflection element 26, reflection prisms 27, 28, 29
Generally constitutes the light projecting portion. Horizontal deflection element (light deflection element) 25 and vertical deflection element (light deflection element) 2
Reference numeral 6 is an acousto-optic device.

The laser diode 23 emits infrared laser light having a wavelength different from that of the distance measuring light of the distance measuring optical system 9. The infrared laser light is made into a parallel light flux by the collimator lens 24 and guided to the horizontal deflection element 25. The horizontal deflection element 25 deflects the infrared laser light in the horizontal direction H as shown in FIG. 7, and the vertical deflection element 26 deflects the infrared laser light in the vertical direction V.

For this deflection, as shown in FIG. 8, the ultrasonic waves output from the oscillators 51 and 52 of the light emission deflection unit 70 are made incident on the crystals of the horizontal direction deflection element 25 and the vertical direction deflection element 26, and the ultrasonic waves are emitted. This is done by changing the frequency of. The control device CPU controls the oscillators 51 and 52 and the laser diode.

As shown in FIG. 9, the horizontal deflection element 25, the vertical deflection element 26, and the laser diode 23 are mounted on a single substrate 60 made of, for example, metal, which has a large heat conduction so that the respective temperatures are the same. It is arranged. Then, a temperature sensor (temperature detecting means) 6 including a thermistor or the like for detecting the temperature of these elements 23, 25, 26.
1 is provided on the substrate 60.

The correction circuit 53 shown in FIG.
The transmitters 51, 52 based on the temperature signal output from 1
Correct the frequency of the ultrasonic wave output by. By this correction, the horizontal deflection element 25 and the vertical deflection element 26
Correct the deflection angle due to.

With this correction, the laser diode 23
The fluctuation of the wavelength due to the temperature change and the fluctuation of the sound velocity in the crystal due to the temperature change of the deflecting elements 25 and 26 are canceled to eliminate the fluctuation of the deflection angle dθ due to the temperature change.

The infrared laser light deflected in the horizontal and vertical directions by the horizontal deflection element 25 and the vertical deflection element 26 is guided to a reflection prism 27, and the reflection prism 2
It is reflected by 7 and guided to the objective lens 30 via the reflecting prisms 28 and 29. A through hole 35 is formed in the objective lens 30 coaxially with the optical axis of the objective lens 30.
The infrared laser beam reflected by the reflection prism 29 is emitted to the outside of the surveying instrument main body 8 through the through hole 35, and the corner cube 2 is searched and scanned by the infrared laser beam.

When the corner cube 2 is within the search range, the infrared laser beam is reflected by the corner cube 2 and returns to the objective lens 30. The infrared laser beam is converged by the objective lens 30, reflected by the reflection prism 32, passes through the noise light removing filter 33, and is imaged on the light receiving element 34. The noise light removing filter 33 is the infrared laser beam. It has a function of transmitting light of the same wavelength as the wavelength of.

When the light receiving element 34 receives the reflected light from the corner cube 2, the control device CPU receives the number of scanning lines and the light received from the start of scanning of the scanning lines at the time when the reflected light is received, as in the conventional case. Until the scanning start position (P1 in FIG. 11)
Find the position from point) to corner cube 2. Then, depending on this position, the optical axis 10a of the scanning optical system 10 (see FIG.
The horizontal and vertical angles from point P0 in 1 to the corner cube 2 are obtained respectively, and the surveying instrument main body is rotated horizontally and vertically by that angle for automatic tracking. 25, the deflection angle of the vertical deflection element 26 is temperature-corrected by the correction circuit 53.

Therefore, the range of the scanning area by the scanning light is always constant regardless of the temperature, and the horizontal and vertical angles from the optical axis 10a to the corner cube 2 can always be accurately determined regardless of the temperature. . As a result, the automatic tracking can be accurately performed regardless of the temperature of the laser diode 23, the deflection elements 25, 26, etc., that is, the environmental temperature.

Further, since the laser diode 23 and the deflecting elements 25 and 26 are provided on one substrate 60 to make the temperatures uniform, only one temperature sensor for detecting the temperature is required, and the laser is used. Since the frequency of the ultrasonic wave is corrected so that the fluctuation of the wavelength due to the temperature change of the diode 23 and the fluctuation of the sound velocity in the crystal due to the temperature change of the deflecting elements 25 and 26 are offset from each other, the correction circuit 53 also has 1 Therefore, it is not necessary to provide a temperature sensor or a correction circuit for each element 23, 25, 26. Therefore, the increase in the number of parts can be suppressed as much as possible, and the cost can be reduced.

[0031]

According to the present invention, the temperature detecting means is used to detect the temperature of the substrate.
Based on the detected signal of the detected temperature detecting means.
The correction means corrects the change in the deflection angle of the light of the light deflection element.
Therefore, it always tracks accurately regardless of the ambient temperature.
be able to. Moreover, it is possible to generate on the same substrate with high heat conduction.
Light is emitted because the optical element and the light deflection element are arranged.
The temperature detection means for detecting the temperature of the element and the light deflection element is
Only one is required, and it is possible to suppress an increase in the number of parts.
Becomes cheaper.

Further, since the optical element and the optical deflecting element are arranged so that the temperatures thereof are the same, only one temperature detecting means for detecting the temperature of each element is required, and the temperature of the optical element is sufficient. If the deflection angle of the optical deflection element is corrected so as to cancel out the variation of the wavelength due to the change and the variation of the deflection angle due to the change of the temperature of the optical deflection element, only one correction means is required, and a temperature sensor or correction means is provided for each element. No need. For this reason,
The increase in the number of parts can be suppressed as much as possible, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration of an automatic tracking surveying instrument according to the present invention.

FIG. 2 is a plan view showing a schematic configuration of an automatic tracking surveying instrument according to the present invention.

FIG. 3 is a perspective view showing a schematic configuration of an automatic tracking surveying instrument according to the present invention.

4 is an optical diagram showing a schematic configuration of a distance measurement optical system of the automatic tracking surveying instrument shown in FIG.

FIG. 5 is a distance measuring optical system, a scanning optical system, and a C according to the present invention.
It is a block diagram which shows the relationship with PU.

6 is an optical diagram showing a schematic configuration of the scanning optical system of FIG.

FIG. 7 is a diagram showing a deflected state of a laser beam.

FIG. 8 is a block diagram showing a configuration of a light emitting deflector in FIG.

FIG. 9 is a side view showing a state in which a laser diode, a horizontal deflection element, and a vertical deflection element are arranged on the same substrate.

FIG. 10 is a graph showing the relationship between the case temperature of a laser diode and the wavelength of laser light.

FIG. 11 is an explanatory diagram showing a relationship among a scanning line, an object, and the center of the scanning region in the scanning region.

[Explanation of symbols]

2 corner cube (object) 23 Laser diode (light emitting element) 25 Horizontal deflection element (optical deflection element) 26 Vertical deflection element (optical deflection element) 53 Correction circuit (correction means) 61 Temperature sensor (temperature detection means)

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Saito 75-1 Hasunuma-cho, Itabashi-ku, Tokyo Topcon Co., Ltd. (56) Reference JP-A-3-282392 (JP, A) JP-A-63- 231313 (JP, A) JP 64-88435 (JP, A) JP 4-166789 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01C 1/00 G01C 5 / 00 G01C 15/00 G01S 17/00

Claims (2)

(57) [Claims] 1. A light deflecting element deflects light emitted from a light emitting element into scanning light, irradiates the object with the scanning light, receives the scanning light reflected by the object, and receives the scanning light. detecting the position of the object, wherein based on the detection result
In an automatic tracking type surveying instrument for automatically tracking the surveying instrument main body to an object , the temperature of the light emitting element and the light deflecting element should be the same.
To place a large same substrate heat conduction, a temperature detecting means for detecting the temperature of the substrate, on the basis of a detection signal which the temperature detecting means detects a temperature
An automatic tracking surveying instrument, comprising: a correction unit that corrects a change in the deflection angle of the light of the light deflection element due to a change . 2. The light deflection element is an acousto-optic element, and the correction means changes the wavelength due to a temperature change of the light emitting element.
And the fluctuation of the sound velocity in the crystal due to the temperature change of the acousto-optic device.
Are incident on the acousto-optic device so that they cancel each other out.
The automatic tracking surveying instrument according to claim 1, wherein the frequency of the ultrasonic wave generated is corrected .