Method for searching for a target object

Abstract

A method for searching for a target object, which is moved along a path, by a measuring device which has a first reference system, a control device, and an operating controller which has a GNSS receiver having a second reference system and which is connectable to the measuring device via a communication connection.

Claims

1. A method for searching for a target object (14), which is moved along a path, by a measuring device (11) which has a first reference system (BZ-1) and an operating controller (12) which has a control device (22) and a GNSS receiver (23) having a second reference system (BZ-2), wherein the operating controller (12) is separate from the measuring device (11) and the target object (14), is co-located with the target object (14), and is connectable to the measuring device (11) via a communication connection (13), comprising the steps of: determining that the measuring device (11) has lost contact with the target object (14), using the GNSS receiver (23) to determine current position coordinates of the operating controller (12) in the second reference system (BZ-2); transforming the current position coordinates of the operating controller (12) from the second reference system (BZ-2) into transformed position coordinates in the first reference system (BZ-1) by the control device (22) by a known transformation function; determining by the control device (22) a starting orientation (32) for the measuring device (11) from the transformed position coordinates of the operating controller (12) in the first reference system, wherein the measuring device (11) in the starting orientation (32) is aligned with the operating controller (12); communicating the starting orientation (32) by the control device (22) via the communication connection (13) to the measuring device (11); and moving the measuring device (11) in accordance with a preset routine to search for the target object (14).

2. The method as claimed in claim 1, wherein while the target object (14) is moving along the path, i-th measurement coordinates (MK.sub.i, i=1 M) are determined in the first reference system (BZ-1) of the measuring device (11) in M, M≥2 measurement positions (MP.sub.i, i, i=1 . . . M) of the target object (14) by the measuring device (11) and j-th GNSS coordinates (K.sub.j, j= . . . N) of the operating controller (12) are determined in the second reference system (BZ-2) of the GNSS receiver (23) in N, N 2 positions (P.sub.j, j=1 . . . N) of the operating controller (12) by the GNSS receiver (23), wherein the i-th measurement coordinates (MK.sub.i) are transmitted from the measuring device (11) to the control device (22) and the j-th GNSS coordinates (K.sub.j) are transmitted from the GNSS receiver (23) to the control device (22).

3. The method as claimed in claim 2, wherein i-th timestamps (t.sub.i, i=1 . . . M) are assigned to the i-th measurement coordinates (MK.sub.1, i=1 . . . M) by the measuring device (11) and j-th timestamps (T.sub.j, j=1 . . . N) are assigned to the j-th GNSS coordinates (K.sub.j, j=1 . . . N) by the GNSS receiver (23), and the i-th timestamps (t.sub.i) and j-th timestamps (T.sub.j) are transmitted to the control device (22).

4. The method as claimed in claim 2, wherein i-th timestamps (t.sub.i, i=1 . . . M) are assigned to the i-th measurement coordinates (MK.sub.i, i=1 . . . M) by the control device (22) and j-th timestamps (T.sub.j, j=1 . . . N) are assigned to the j-th GNSS coordinates (K.sub.j, j=1 . . . N) by the control device (22).

5. The method as claimed in claim 3, wherein j-th GNSS coordinates (K.sub.j) are assigned to i-th measurement coordinates (MK.sub.i) by the control device (22) if a time difference (Δt.sub.ij) between the i-th timestamp (t.sub.i) of the i-th measurement coordinates (MK.sub.i) and the j-th timestamp (T.sub.j) of the j-th GNSS coordinates (K.sub.j) is minimal.

6. The method as claimed in claim 3, wherein j-th GNSS coordinates (K.sub.j) are assigned to i-th measurement coordinates (MK.sub.i) by the control device (22) if a time difference (Δt.sub.ij) between the i-th timestamp (t) of the i-th measurement coordinates (MK.sub.i) and the j-th timestamp (T.sub.j) of the j-th GNSS coordinates (K.sub.j) is less than a preset maximum time difference (Δt.sub.max).

7. The method as claimed in claim 5, wherein the transformation function between the second reference system (BZ-2) and the first reference system (BZ-1) is determined by the control device (22) at least in part by the i-th measurement coordinates (MK.sub.i, i=1 M) and the j-th GNSS coordinates (K.sub.j, j=1 . . . N).

8. The method as claimed in claim 3, further comprising the steps of: determining the i-th measurement coordinates (MK.sub.i, i=1 . . . M) and i-th timestamps (t.sub.i, i=1 . . . M) as first data points by the control device (22); adapting a first fit curve for the first data points by the control device (22); determining by the control device (22) first approximation coordinates from the first fit curve at first times (.Math..sub.1k), wherein the first times (.Math..sub.1k) correspond to the j-th timestamps (T.sub.j, j=1 . . . N) of the j-th GNSS coordinates (K.sub.j, j=1 . . . N); and determining the transformation function between the second reference system (BZ-2) and the first reference system (BZ-1) by the control device (22) at least in part by the first approximation coordinates and the j-th GNSS coordinates (K.sub.j, j=1 . . . N).

9. The method as claimed in claim 3, further comprising the steps of: determining the j-th GNSS coordinates (K.sub.j, j=1 . . . N) and j-th timestamps (T.sub.j j=1 . . . N) as second data points by the control device (22); adapting a second fit curve for the second data points by the control device (22); determining by the control device (22) second approximation coordinates from the second fit curve at second times (.Math..sub.2k), wherein the second times (.Math..sub.2k) correspond to the i-th timestamps (t.sub.i) of the i-th measurement coordinates; and determining the transformation function between the second reference system (BZ-2) and the first reference system (BZ-1) by the control device (22) at least in part by the i-th measurement coordinates (MK.sub.i, i=1 . . . M) and second approximation coordinates.

10. The method as claimed in claim 3, further comprising the steps of: determining the i-th measurement coordinates (MK.sub.i, i=1 . . . M) and i-th timestamps (t.sub.i, i=1 . . . M) as first data points by the control device (22), and a first fit curve is adapted for the first data points by the control device (22); determining the j-th GNSS coordinates (P.sub.j, j=1 . . . N) and j-th timestamps (T.sub.j, j=1 . . . N) as second data points by the control device (22), and a second fit curve is adapted for the second data points by the control device (22); determining by the control device (22) first approximation coordinates from the first fit curve and second approximation coordinates from the second fit curve at prescribed times (.Math..sub.k); and determining the transformation function between the second reference system (BZ-2) and the first reference system (BZ-1) of the measuring device (11) by the control device (22) at least in part by the first approximation coordinates and second approximation coordinates.

11. An apparatus for performing the method for searching for the target object (14) as claimed in claim 1, comprising: a measuring device (11); an operating controller (12) which has a control device (22) and a GNSS receiver (23); and a communication connection (13) which connects the measuring device (11) and the operating controller (12) to one another.

12. The apparatus as claimed in claim 11, wherein the GNSS receiver (23) is permanently installed in the operating controller (12).

13. The apparatus as claimed in claim 11, wherein the GNSS receiver (23) is connected to the operating controller (12) via a data interface (26).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGS. 1A and B show an apparatus having a measuring device, an operating controller and a communication connection in a three-dimensional depiction (FIG. 1A) and in a block diagram (FIG. 1B);

(2) FIGS. 2A and B show an arrangement in which the measuring device has lost contact with a target object and a method according to the invention is used to search for a target object; and

(3) FIG. 3 shows a scenario that can be used to determine a transformation function between a second reference system of a GNSS receiver and a first reference system of the measuring device.

DETAILED DESCRIPTION OF THE DRAWINGS

(4) FIGS. 1A and B show an apparatus 10, which comprises a measuring device 11, an operating controller 12 and a communication connection 13, for performing a method according to the invention for searching for a target object. FIG. 1A shows the apparatus in a three-dimensional depiction and FIG. 1B shows the design of the apparatus 10 in a block diagram.

(5) The communication connection 13 connects the measuring device 11 and the operating controller 12 to one another and is in the form of a wireless communication connection. Suitable wireless communication connections are all known technologies for data transfer, such as for example Bluetooth, radio, WiFi, infrared, etc. The measuring device 11 is in the form of a total station and is used inter alia to track a target object 14; the target object 14 is in the form of a passive target object. The measuring device 11 comprises a distance measuring unit 15 and an angle measuring unit 16. The target object 14 is mounted on a support rod 17 and is moved by a user. The support rod 17 can have a receiving element mounted on it that receives the operating controller 12; alternatively, the user can hold the operating controller 12 in his hand during movement of the support rod 17.

(6) During the tracking of the target object 14 by the measuring device 11, it is possible for the measuring device 11 to lose contact with the target object 14 and not be able to determine measurement coordinates at the measurement position of the target object 14. This situation is also referred to as “loss of contact”. To improve searching for the target object 14 and reduce the time required therefor, the apparatus 10 can perform a method according to the invention for searching for the target object 14.

(7) The operating controller 12 comprises a housing 21, a control device 22, which is arranged inside the housing 21, a GNSS receiver 23, which is arranged inside the housing 21, an operating device 24 and a display device 25. The GNSS receiver 23 in the exemplary embodiment is permanently installed in the housing 21; alternatively, the GNSS receiver can be in the form of an external GNSS receiver and connected to the control device 22 via a data interface 26 of the operating controller 12.

(8) The operating device 24 and display device 25 in the exemplary embodiment are in the form of separate elements in the form of a keypad and a display; alternatively, the operating device 24 and display device 25 can be integrated in a touchscreen together. The operating device 24 and display device 25 are embedded in the housing 21 of the operating controller 12 and permanently connected to the housing 21; alternatively, the operating device 24 and the display device 25 or the operating and display device 24, 25 can be in the form of separate elements and connected to the control device 22 via a data interface (USB, Bluetooth, WiFi).

(9) FIGS. 2A and B schematically show an arrangement in which the measuring device 11 has lost contact with the target object 14 and the method according to the invention is used to search for a target object. FIG. 1A shows the measuring device 11 in an orientation in which the target object 14 is situated outside a field of view 31 of the measuring device 11; the measuring device 11 has lost contact with the target object 14.

(10) Performance of the method according to the invention for searching for a target object is controlled by the control device 22 of the operating controller 12. The control device 22 gives a command to the GNSS receiver 23 to determine current position coordinates P.sub.curr of the operating controller 12 in the second reference system BZ-2 of the GNSS receiver 23. The current position coordinates P.sub.curr of the operating controller 12 are transformed into transformed position coordinates in the first reference system BZ-1 of the measuring device 11 by the control device 22 by means of a known transformation function. Subsequently, the control device 22 determines a starting orientation 32 for the measuring device 11 from the transformed position coordinates of the operating controller 12. In this case, the starting orientation 32 corresponds to an orientation of the measuring device 11 in which the measuring device 11 is aligned with the transformed position coordinates of the operating controller 12. The measuring device 11 is moved from the starting orientation 32 in accordance with a preset routine in order to search for the target object 14.

(11) The method according to the invention for searching for a target object presupposes that the transformation function between the second reference system BZ-2 and the first reference system BZ-1 is known. FIG. 3 shows a scenario that can be used to determine the transformation function. The target object 14 is moved along a path by a user. The measuring device 11 captures measurement coordinates in multiple measurement positions of the target object 14, and the GNSS receiver 23 captures GNSS coordinates in multiple positions of the operating controller 12. The exemplary embodiment shows six measurement positions for the target object 14 and six positions for the operating controller 12. In the general case, the target object 14 is arranged in M different measurement positions MP.sub.i, i=1 . . . M, and the operating controller 12 is arranged in N different positions P.sub.i, j=2 . . . N. The numbers M and N may be identical or different. In each measurement position MP.sub.i, the measuring device 11 determines i-th measurement coordinates MK.sub.i, i=1 . . . M for the target object 14, wherein the i-th measurement coordinates MK.sub.i are captured in a first reference system BZ-1 of the measuring device 11. In each position P.sub.j, the GNSS receiver 23 determines j-th GNSS coordinates K.sub.j, j=1 . . . N for the operating controller 12, wherein the j-th GNSS coordinates K.sub.j are captured in a second reference system BZ-2 of the GNSS receiver 23.

(12) In a first variant, the i-th measurement coordinates MK.sub.i and i-th timestamps t.sub.i are determined as first data points by the control device 22. The control device 22 adapts a first fit curve for the first data points, wherein known fit curves can be used. The control device 22 determines first approximation coordinates from the first fit curve at first times τ.sub.1k, wherein the first times τ.sub.1k correspond to the j-th timestamps T.sub.j of the j-th GNSS coordinates K.sub.j. The control device 22 determines the transformation function between the second reference system BZ-2 of the GNSS receiver 23 and the first reference system BZ-1 of the measuring device 11 by using the first approximation coordinates and the j-th GNSS coordinates K.sub.j.

(13) In a second variant, the j-th GNSS coordinates K.sub.j and j-th timestamps T.sub.j are determined as second data points by the control device 22. The control device 22 adapts a second fit curve for the second data points, wherein known fit curves can be used. The control device 22 determines second approximation coordinates from the second fit curve at second times τ.sub.2k, wherein the second times τ.sub.2k correspond to the i-th timestamps t.sub.i of the i-th measurement coordinates. The control device 22 determines the transformation function between the second reference system BZ-2 of the GNSS receiver 23 and the first reference system BZ-1 of the measuring device 11 by using the i-th measurement coordinates MK.sub.i and the second approximation coordinates.

(14) In a third variant, the i-th measurement coordinates MK.sub.i and i-th timestamps t.sub.j are determined as first data points by the control device 22, and a first fit curve is adapted for the first data points by the control device 22. The j-th GNSS coordinates P.sub.j and j-th timestamps T.sub.j are determined as second data points by the control device 22, and a second fit curve is adapted for the second data points by the control device 22. The control device 22 determines first approximation coordinates from the first fit curve and second approximation coordinates from the second fit curve at prescribed times τ.sub.k. The control device 22 determines the transformation function between the second reference system BZ-2 of the GNSS receiver 23 and the first reference system BZ-1 of the measuring device 11 by using the first approximation coordinates and second approximation coordinates.