Measuring Method And Measuring Instrument

• US 20120081691A1
• Filed: 07/14/2011
• Published: 04/05/2012
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Topcon
• Original Assignee: Kabushiki Kaisha Topcon
• Inventors: Nagai, Katsuyuki
• Granted Patent: US 8,908,169 B2
• Time in Patent Office: Days
• US Class Current: 356/4.01
• CPC Class Codes: G01C 1/04 combined with cameras
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01C 3/04 Adaptation of rangefinders for combination with telescopes or binoculars
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 7/4808 Evaluating distance, position or velocity data
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/4972 Alignment of sensor
• CPC Class Codes: G03B 37/00 Panoramic or wide-screen photography; Photographing extended surfaces, e.g. for surveying; Photographing internal surfaces, e.g. of pipe

Abstract

The invention provides the measuring method for performing monitoring measurement on a plurality of measuring points by using a measuring instrument 1, which comprises a telescope unit for performing sighting of a measuring point where an initial value is already known, a distance measuring unit 29 for measuring a distance to the measuring point by projecting a distance measuring light through the telescope unit, an image sensor 23 for taking an image in direction of measurement and for acquiring a digital image, angle detecting units 31, 32 each for detecting a directional angle in sighting direction of the telescope unit, and an arithmetic unit 27 for making the telescope unit perform automatic sighting to the measuring point and for calculating directional angles of the measuring point based on a deviation of the measuring point on the digital image from a sighting axis and based on a result of detection from the angle detecting unit, wherein the monitoring measurement comprises a coarse monitoring measurement for acquiring a digital image in measuring direction and for performing angle measurement on the measuring point from the digital image, and a precise monitoring measurement for performing sighting of the measuring point by the telescope unit and for performing distance measurement by the distance measuring unit and angle measurement by the angle detecting unit, and wherein the coarse monitoring measurement is executed on each of the measuring points, a deviation of a result of the coarse measurement by the coarse monitoring measurement from the initial value is determined, and the precise monitoring measurement is executed on the measuring point where the deviation exceeds a first threshold value.

Claims

1. A measuring method for performing monitoring measurement on a plurality of measuring points by using a measuring instrument, which comprises a telescope unit for performing sighting of a measuring point where an initial value is already known, a distance measuring unit for measuring a distance to the measuring point by projecting a distance measuring light through said telescope unit, an image sensor for taking an image in direction of measurement and for acquiring a digital image, angle detecting units each for detecting a directional angle in sighting direction of said telescope unit, and an arithmetic unit for making said telescope unit perform automatic sighting to the measuring point and for calculating directional angles of the measuring point based on a deviation of the measuring point on the digital image from a sighting axis and based on a result of detection from said angle detecting unit, wherein said monitoring measurement comprises a coarse monitoring measurement for acquiring a digital image in measuring direction and for performing angle measurement on the measuring point from the digital image, and a precise monitoring measurement for performing sighting of the measuring point by said telescope unit and for performing distance measurement by said distance measuring unit and angle measurement by said angle detecting unit, and wherein the coarse monitoring measurement is executed on each of the measuring points, a deviation of a result of the coarse measurement by said coarse monitoring measurement from the initial value is determined, and the precise monitoring measurement is executed on the measuring point where the deviation exceeds a first threshold value.

2. A measuring method according to claim 1, wherein said coarse monitoring measurement comprises a step of directing said telescope unit toward the measuring point based on the initial value and of acquiring a digital image, a step of measuring a directional angle of a sighting axis of said telescope unit, a step of calculating the deviation of the measuring point in the digital image with respect to the sighting axis, and a step of determining the directional angles of the measuring point based on a vertical angle, a horizontal angle, and the deviation.

3. A measuring method according to claim 1, wherein said coarse monitoring measurement is performed so that said telescope unit performs scanning over a preset range, and said coarse monitoring measurement comprises a step of setting scanning speed and image pickup time interval in such manner that an image of the object to be measured is included in at least two digital images, being adjacent to each other in terms of time, and a step of averaging the obtained measurement result.

4. A measuring method according to claim 1, wherein an alarm signal is issued when a deviation of the measurement result of the precise monitoring measurement from the initial value exceeds a second threshold value.

5. A measuring method according to claim 1, wherein said method comprises a step of acquiring an image of the background in the measuring direction at the same time as the execution of the coarse monitoring measurement or as the execution of the precise monitoring measurement, and a step of judging a non-measurable state according to an image of the background in case the coarse monitoring measurement or the precise monitoring measurement cannot be performed.

6. A measuring instrument, comprising a telescope unit for performing sighting of a measuring point where an initial value is already known, a distance measuring unit for measuring a distance to the measuring point by projecting a distance measuring light through said telescope unit, an image sensor for taking an image in sighting direction and for acquiring a digital image, angle detecting units each for detecting a directional angle in sighting direction of said telescope unit, an automatic sighting unit for making said telescope unit perform automatic sighting on the measuring point, an image processing unit for detecting the measuring point in the digital image and for calculating a field angle with respect to a sighting axis of a telescope, and an arithmetic unit, wherein said arithmetic unit directs said telescope unit toward the measuring point according to the initial value, calculates directional angles of the measuring point based on the directional angle detected by said angle detecting unit and also based on the field angle, acquires the directional angles thus calculated as a result of coarse monitoring measurement, and in case the result of the coarse monitoring measurement exceeds a first threshold value, said arithmetic unit makes said telescope unit direct toward the measuring point exceeding the first threshold value, makes said telescope unit perform automatic sighting, carries out distance measurement and angle measurement by said distance measuring unit and said angle measuring unit and acquires the measurement result as a result of the precise monitoring measurement.

7. A measuring instrument according to claim 6, wherein said telescope unit has an image pickup unit for taking an image of background in the measuring direction, and in case where the result of coarse monitoring measurement or the result of precise monitoring measurement cannot be obtained, said arithmetic unit acquires an image of the background in direction of the measuring point where measurement result cannot be obtained by said image pickup unit.