AUTOMATIC COLLIMATION DEVICE FOR SURVEYING APPARATUS

Abstract

A surveying apparatus that is capable of automatic collimation based on an image obtained from an imaging device, which enables carrying out automatic collimation without using angle detectors, even when a telescope is rotating. An automatic collimation device for a surveying apparatus including: an imaging device that images a target (11) captured by a telescope and surroundings of the target; a drive unit that rotates the telescope; a light emitting unit that sends light toward the target; and an arithmetic control unit that determines a position of the target based on a difference between a lit image (a) obtained when the light emitting unit has been turned on and an unlit image (b) obtained when the light emitting unit has been turned off and controls the drive unit to automatically collimate the target, wherein the arithmetic control unit determines, while shifting either the lit image or unlit image little by little (C), a position where both images are most coincident (D), and determines a position of the target based on a difference between both images at the position (E).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[FIG. 1] A block diagram of an automatic collimation device for a surveying apparatus, which is a first embodiment of the present invention.

[FIG. 2] A diagram for explaining an optical system of the automatic collimation device.

[FIG. 3] A plan view of an area sensor used for the automatic collimation device.

[FIG. 4] An optical system for which the automatic collimation device has been incorporated into a total station.

[FIG. 5] Views for explaining principles of the automatic collimation device.

[FIG. 6] A diagram for explaining a correlation.

[FIG. 7] Views for explaining a method for determining a range by which a lit image and an unlit image are shifted when carrying out a correlation operation of both images.

[FIG. 8] Views for explaining principles of an automatic collimation device for a surveying apparatus, which is a second embodiment of the present invention.

[FIG. 9] An optical system for which an automatic collimation device of a third embodiment of the present invention has been incorporated into an automatic level.

[FIG. 10] An optical system for which an automatic collimation device of a third embodiment of the present invention has been incorporated into an electronic level.

[FIG. 11] A diagram for explaining an optical system of a conventional surveying apparatus with an imaging device.

[FIG. 12] Views for explaining principles of an automatic collimation device for a conventional surveying apparatus with an imaging device.

Claims

1. An automatic collimation device for a surveying apparatus comprising: an imaging device that images a target captured by a telescope and surroundings of the target; a drive unit that rotates the telescope; a light emitting unit that sends light toward the target; and an arithmetic control unit that determines a position of the target based on a difference between a lit image obtained as a result of imaging by the imaging device when the light emitting unit has been turned on and an unlit image obtained as a result of imaging by the imaging device when the light emitting unit has been turned off and controls the drive unit to automatically collimate the target, wherein the arithmetic control unit carries out a correlation operation between the lit image and unlit image so as to determine a position where both images are most coincident, and determines a position of the target based on a difference between both images at the position.

2. The automatic collimation device for a surveying apparatus according to claim 1, wherein the position where both images are most coincident is judged to be when, in the course of a correlation operation between the lit image and unlit image to determine a correlation regarding brightness of overlapping pixels between both images, the correlation has been maximized.

3. The automatic collimation device for a surveying apparatus according to claim 1, wherein the position where both images are most coincident is judged to be when, in the course of a correlation operation between the lit image and unlit image in a transverse direction to determine, in overlapping parts between both images, a correlation regarding a sum total of brightness of overlapping pixels on a straight line along a longitudinal direction between both images, the correlation has been maximized.

4. The automatic collimation device for a surveying apparatus according to claim 1, wherein the position where both images are most coincident is judged to be when, in the course of a correlation operation between the lit image and unlit image in a longitudinal direction to determine a correlation regarding a sum total of brightness of overlapping pixels on a straight line along a transverse direction between both images, the correlation has been maximized.

5. The automatic collimation device for a surveying apparatus according to claim 1, wherein the correlation operation is carried out while shifting either the lit image or unlit image, and the range to be shifted at this time is limited to a range estimated from a control signal transmitted from the arithmetic control unit to the drive unit.