US-12624945-B2 - Surveying target and method with light sector power optimization

US12624945B2US 12624945 B2US12624945 B2US 12624945B2US-12624945-B2

Abstract

A target ( 100 ) for use in surveying applications is provided. The target comprises a plurality of light sources ( 106 ) arranged around a longitudinal axis (A) of a base element ( 108 ) of the target. The plurality of light sources is configured to emit light radially. The target further comprises a sensor unit ( 216 ) a control unit ( 214 ). The control unit is configured to obtain information regarding an orientation (α) of said target relative to a surveying instrument ( 120 ) aimed at the target, based on at least a measurement received from the sensor unit. The control unit is further configured to identify, based on the obtained information regarding the orientation of the target relative to the surveying instrument, a first subset ( 106 c - 106 e ) of the plurality of light sources arranged to emit light towards the surveying instrument, and a second subset ( 106 a , 106 b , 106 f - 106 h ) of the plurality of light sources arranged to emit light away from the surveying instrument. The control unit is further configured to control the plurality of light sources such that the first subset of light sources emit light with a higher intensity than the second subset of light sources.

Inventors

Christian Graesser
Jacques Rondeau

Assignees

TRIMBLE INC.

Dates

Publication Date: 20260512
Application Date: 20231215
Priority Date: 20230310

Claims (17)

1 . A target for use in surveying applications, the target comprising: a plurality of light sources arranged around a longitudinal axis of a base element of said target and configured to emit light radially; a sensor unit; and a control unit configured to: obtain information regarding an orientation of said target relative to a surveying instrument aimed at said target, based on at least a measurement received from said sensor unit; identify, based on the obtained information regarding the orientation of the target relative to the surveying instrument, a first subset of the plurality of light sources arranged to emit light towards the surveying instrument, and a second subset of the plurality of light sources arranged to emit light away from the surveying instrument; and control the plurality of light sources such that the first subset of light sources emit light with a higher intensity than the second subset of light sources.
2 . A method for operating a target for use in surveying applications, the target comprising a plurality of light sources arranged around a longitudinal axis of a base element of said target and configured to emit light radially, the method comprising: obtaining information regarding an orientation of said target relative to a surveying instrument aimed at said target based on at least a measurement received from a sensor unit of the target; identifying, based on the obtained information regarding the orientation of the target relative to the surveying instrument, a first subset of the plurality of light sources arranged to emit light towards the surveying instrument, and a second subset of the plurality of light sources arranged to emit light away from the surveying instrument; and controlling the plurality of light sources such that the first subset of light sources emit light with a higher intensity than the second subset of light sources.
3 . The target of claim 1 , wherein: said sensor unit comprises a plurality of sensors distributed around the longitudinal axis of the base element of the target, and configured to detect a signal emitted by the surveying instrument.
4 . The target of claim 1 , wherein: said sensor unit comprises at least one imaging sensor configured to obtain at least one image of a surrounding of the target.
5 . The method of claim 2 , wherein the information regarding the orientation of the target relative to the surveying instrument is obtained by: receiving, from the surveying instrument, an input indicative of a surveying instrument orientation in a common reference frame; determining, based on measurements received from said sensor unit, a target orientation in the common reference frame; and determining, based on the received input and the determined target orientation in the common reference frame, the orientation of the target relative to the surveying instrument.
6 . The target of claim 1 , wherein: said sensor unit comprises a compass.
7 . The target of claim 1 , wherein: said sensor unit comprises an inertial measurement unit, IMU.
8 . The method of claim 2 , wherein: the information regarding an orientation of the target relative to the surveying instrument obtained by: receiving, from the surveying instrument, a position of the surveying instrument in a common reference frame; obtaining, based on a position input received from an external sender, a position of the target in the common reference frame; determining, based on measurements received from said sensor unit, a target orientation in the common reference frame; and determining the orientation of the target relative to the surveying instrument based on the position of the surveying instrument, the position of the target, and the target orientation, in the common reference frame.
9 . The target of claim 1 , wherein: said sensor unit comprises a global navigation satellite system, GNSS, receiver.
10 . The method of claim 8 , wherein said position input received from an external sender comprises a target position input received from said surveying instrument.
11 . The method of claim 2 , wherein the control of the plurality of light sources comprises controlling the second subset of light sources to be turned off.
12 . The target of claim 1 , wherein said plurality of light sources comprises at least six light sources arranged symmetrically around the longitudinal axis of the base element.
13 . The method of claim 2 , wherein said sensor unit comprises a plurality of sensors distributed around the longitudinal axis of the base element of the target, configured to detect a signal emitted by the surveying instrument, and the information regarding the orientation of the target relative to the surveying instrument is obtained by: obtaining, from said plurality of sensors, a detection of a signal emitted by the surveying instrument toward the target; and determining the orientation of the target relative to the surveying instrument based on a relative signal strength, of the signal, detected by the plurality of sensors.
14 . The method of claim 2 , wherein said sensor unit comprises at least one imaging sensor configured to obtain at least one image of a surrounding of the target, and the information regarding the orientation of the target relative to the surveying instrument is obtained by: obtaining, from the at least one imaging sensor, at least one image of a surrounding of the target; identifying a surveying instrument in the obtained image; and determining the orientation of the target relative to the surveying instrument based on a position of the identified surveying instrument in the obtained image.
15 . The method of claim 2 , wherein said sensor unit comprises a compass, a common reference frame is a global reference frame, and the determination of the target orientation in the common reference frame comprises: receiving a measurement from the compass; and determining the target orientation in the common reference frame based on the measurement from the compass.
16 . The method of claim 2 , wherein said sensor unit comprises an inertial measurement unit, IMU, and the determination of the target orientation in a common reference frame comprises: determining a first position track of the target, in a target reference frame, based on measurements from said IMU; obtaining a second position track of the target, in the common reference frame, based on a position input received from an external sender; and determining the target orientation in the common reference frame by aligning said first position track and said second position track.
17 . The method of claim 8 , wherein said sensor unit comprises a global navigation satellite system, GNSS, receiver, and wherein said position input received from an external sender comprises a target position input received via said GNSS receiver.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application No. 23161296.1, filed Mar. 10, 2023, the entire contents of which are incorporated herein by reference for all purposes. TECHNICAL FIELD The present disclosure relates generally to the field of surveying equipment. More specifically, it relates to energy optimization in a target for use in surveying applications. BACKGROUND The art of surveying involves the determination of unknown positions or setting out of known coordinates using angle and distance measurements taken from one or more positions. In surveying operations, a surveying device or instrument is often used to determine one or more positions of a target. An example of such a surveying instrument is a total station which is a distance measuring instrument with an integrated distance and angular measurement unit, which combines electronic, optical and computer techniques. The surveying instrument may furthermore be provided with a computer or control unit with writable information for measurements to be performed and for storing data obtained during the measurements. Preferably, the surveying instrument, calculates the position of a target in a fixed ground-based coordinate system. The target may emit light detectable by the surveying instrument. The surveying instrument may be configured to identify and track the target based on light emitted by the target. SUMMARY One general aim of the present disclosure is to optimize power consumption by the target to increase battery time and improve autonomy of the target. Specifically, there is a desire to be able to improve the control of light sources of the target. It is therefore an object of the present invention to meet at least some of the above-mentioned goals and to provide an improved target for surveying operations and a method for operating the target. This and other objects are achieved by means of a target and a method as defined in the appended independent claim. Other embodiments are defined by the dependent claims. According to a first aspect of the present disclosure, a target for use in surveying applications is provided. The target comprises a plurality of light sources arranged around a longitudinal axis of a base element of the target. The plurality of light sources is configured to emit light radially. The target further comprises a sensor unit and a control unit. The control unit is configured to obtain information regarding an orientation of the target relative to a surveying instrument aimed at the target based on at least a measurement received from the sensor unit. The control unit is further configured to identify, based on the obtained information regarding the orientation of the target relative to the surveying instrument, a first subset of the plurality of light sources arranged to emit light towards the surveying instrument, and a second subset of the plurality of light sources arranged to emit light away from the surveying instrument. The control unit is further configured to control the plurality of light sources such that the first subset of light sources emit light with a higher intensity than the second subset of light sources. According to a second aspect of the present disclosure, a method for operating a target for use in surveying operations is provided. The target comprises a plurality of light sources arranged around a longitudinal axis of a base element of the target and configured to emit light radially. The target may be a target as described with reference to the first aspect of the present disclosure. The method comprises obtaining information regarding an orientation of the target relative to a surveying instrument aimed at the target based on at least a measurement received from a sensor unit of the target. The method further comprises identifying, based on the obtained information regarding the orientation of the target relative to surveying instrument, a first subset of the plurality of light sources arranged to emit light towards the surveying instrument, and a second subset of the plurality of light sources arranged to emit light away from the surveying instrument. The method further comprises controlling the plurality of light sources such that the first subset of light sources emit light with a higher intensity than the second subset of light sources. The light sources may for example include light-emitting diodes (LEDs). The light sources may for example be arranged symmetrically around the longitudinal axis of the base element. The light sources may be arranged in one or more rows around the base element. The longitudinal axis may be an axis of the target which, during operation of the target, is in a substantially vertical direction. During operation, the light sources may, in some embodiments, be arranged to emit light substantially horizontally. The surveying instrument may comprise a light detector configured to detect light emitted by the lig