APPARATUS FOR MEASURING A STRUCTURE AND ASSOCIATED METHOD

Abstract

A measuring apparatus for measuring a structure comprises at least one measurement sensor configured to measure the structure, a bearing platform configured to carry the at least one measurement sensor and a control. The control is configured to specify at least one quality reference value for at least one characteristic of measurement quality, and further configured to adjust one or more parameters of the measuring apparatus which influence the at least one characteristic of measurement quality. An actual quality value is determined and approaches the at least one quality reference value as the one or more parameters are adjusted.

Claims

1. A method for measuring a structure to assess for damage and monitor construction, the method comprising: providing a measuring apparatus configured to move along the structure, the measuring apparatus comprising, at least one measurement sensor, and a bearing platform configured to carry the at least one measurement sensor; measuring the structure using the at least one measurement sensor; determining one or more parameters of the measuring apparatus; specifying at least one quality reference value for at least one quality characteristic, wherein the at least one quality reference value indicates a desired level of quality for the measuring of the structure; and adjusting the one or more parameters during the measuring to achieve the at least one specified quality reference value, wherein the one or more parameters influence the at least one quality characteristic.

2. The method according to claim 1, wherein the at least one quality characteristic comprises at least one of accuracy, precision, resolution, reliability, completeness, reproducibility of structural data of the structure acquired by measurement, and time required for completion of the measurement.

3. The method according to claim 1, wherein the at least one measurement sensor is configured to automatically regulate the one or more parameters relative to the structure and is positioned relative to the structure.

4. The method according to claim 1, wherein the one or more parameters influencing the at least one quality characteristic comprises at least one of position of the at least one measurement sensor with respect to the structure, spacing between the at least one measurement sensor and the structure, height position of the at least one measurement sensor relative to the structure, orientation of the at least one measurement sensor with respect to the structure, drift of the bearing platform, orientation of the bearing platform, operational speed of the bearing platform, acceleration of the bearing platform, scan rate of the at least one measurement sensor, and measurement frequency of the at least one measurement sensor.

5. The method according to claim 4, wherein the at least one measurement sensor is configured to be adjusted relative to the bearing platform.

6. The method according to claim 5, wherein the at least one measurement sensor is configured to rotate relative to the bearing platform around at least one axis of rotation.

7. The method according to claim 6, wherein the at least one measurement sensor is configured to be adjusted in height and in a lateral direction in a translatory manner relative to the structure and relative to the bearing platform, and wherein the bearing platform further comprises a drive configured to move the bearing platform toward and away from the structure.

8. The method according to claim 7, wherein the at least one measurement sensor emits one of electromagnetic radiation and soundwaves, and wherein the at least one measuring sensor is orientated with respect to the structure such that the one of radiation and soundwaves emitted by the sensor strike a surface of the structure at a 90 angle.

9. The method according to claim 8, wherein during the measurement of the structure, a position of the measuring apparatus is determined and assigned to structural data recorded during measurement.

10. The method according to claim 1, wherein the structure is measured multiple times and a structural change is determined by comparing the multiple measurements.

11. The method according to claim 1, wherein the at least one quality reference value is used for planning a route.

12. The method according to claim 11, wherein the planned route includes specifications for one or more control variables, wherein the one or more control variables comprise at least one of trajectory of the bearing platform, operational speed of the bearing platform, acceleration of the bearing platform, orientation of the at least one measurement sensor with respect to the structure, a control variable related to a material and a control variable which accounts for a surface of the structure.

13. The method according to claim 11, wherein the rout planning comprises subdividing an area of movement for the bearing platform which surrounds the structure into sectors of various measurement quality, wherein the planned route is placed through the sectors which achieve at least the specified quality reference value.

14. A method for measuring a structure using a measuring apparatus moving along the structure to be measured, the method comprising: measuring the structure using at least one measurement sensor of the measuring apparatus; providing at least one quality reference value for at least one characteristic of measurement quality; determining one or more parameters of the measuring apparatus, wherein the one or more parameters influence the at least one characteristic of measurement quality; determining an actual quality value based on the one or more parameters; and regulating the one or more parameters so the determined actual quality value approaches the at least one quality reference value.

15. A measuring apparatus for measuring a structure, the measuring apparatus comprising: at least one measurement sensor configured to measure the structure; a bearing platform configured to carry the at least one measurement sensor; and a control configured to specify at least one quality reference value for at least one characteristic of measurement quality and to adjust one or more parameters of the measuring apparatus which influence the at least one characteristic of measurement quality, wherein an actual quality value is determined and approaches the at least one quality reference value as the one or more parameters are adjusted.

16. The measuring apparatus according to claim 15, wherein the bearing platform is moved by one of a land vehicle, a watercraft, and an aircraft.

17. The measuring apparatus according to claim 15, wherein the at least one measurement sensor comprises at least one of a laser scanner, a camera, an echo sounder, a multi-beam sensor, and a side-scan sonar.

18. The measuring apparatus according to claim 15, further comprising at least one locating unit configured to determine a position of the measuring apparatus.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] One embodiment of the invention is explained below using figures below where:

[0034] FIG. 1 illustrates a perspective view of an embodiment of a measuring apparatus;

[0035] FIG. 2 illustrates the embodiment of the measuring apparatus of FIG. 1 performing measurements of a bulkhead;

[0036] FIG. 3 illustrates a schematic view of a trajectory defined for the measuring apparatus as part of route planning; and

[0037] FIG. 4 illustrates measurement of a bulkhead and of a water body substrate by the measuring apparatus in multiple runs.

[0038] If not otherwise specified, the same reference numbers indicate the same objects below.

DETAILED DESCRIPTION OF THE INVENTION

[0039] FIG. 1 shows an embodiment of a measuring apparatus 10 for measuring a port construction. The measuring apparatus 10 comprises a buoyant bearing platform 12 in the form of a boat, a scanner above water 14, a scanner below water 16, a camera 18 and a GNSS receiving unit 20. The scanners and camera 14, 16 and 18 include measurement sensors 14, 16, 18 that are used for measuring a structure. The measurement sensors 14, 16, 18 can be arranged in a manner not depicted on a shared sensor platform. Furthermore, a reflector 22 is situated on the bearing platform 12. The measuring apparatus 10 also has a drive, not shown and situated on the bearing platform, with which the bearing platform 12 is actively powered and thus able to be moved along a structure for a measurement run.

[0040] FIG. 2 shows the measuring apparatus 10 during measurement of a structure close to water, specifically a bulkhead 28 in the present case. There is also a tacheometer 26 situated on land. The tacheometer 26 is directed at the reflector 22 of the bearing platform 12. However, the tacheometer is fundamentally optional and in particular not required for the inventive method. The Tacheometer can be used if the GNSS signal provides no precise data due to shadowing effects, for example. The measuring apparatus 10 moves along the bulkhead 28 on a trajectory 30 and investigates said bulkhead with its measurement sensors 14, 16, 18. The area of the bulkhead 28 already measured is visible with a three-dimensional structure in FIG. 2. During their measurement, the measurement sensors 14, 16, 18 record structural data for the bulkhead, such as damage, in a manner generally known. Thus, for example, the sensors 14, 16, 18 can be laser scanners which can provide information on the relief from the signal transit times and information on the surface condition of the bulkhead from reflection data as structural data. The sensor or scanner 16 can also be an echo sounder providing corresponding data. The sensor 18 can be a camera providing color images of the bulkhead. The structural data determined by the sensors 14, 16, 18 can be associated with location data for the bearing platform 12 via a control unit. The GNSS receiving unit 20, which receives GNSS signals from satellites 24 of a global navigation satellite system in a manner generally known, is used for determining the location of the bearing platform 12, as is an inertial measuring unit, which is not shown. The tacheometer 26 can also be used to determine the position of the measuring apparatus 10, in particular if the GNSS signal is not available.

[0041] The specified trajectory 30 was defined as part of planning the route. This trajectory was defined based on a preferred level of quality to achieve for the measurement. This level of quality is influenced by multiple quality characteristics, with a quality reference value having been specified for at least one of the quality characteristics. The distance of one or more of the measurement sensors 14, 16, 18 with respect to the bulkhead 28 is included particularly for this in planning the route and thus the trajectory as a parameter influencing measurement quality. Here a distance of the measuring apparatus and thus of the respective sensors from the bulkhead 28 is regulated during the run of the measuring apparatus 10 along the bulkhead such that the quality reference value is achieved. The measuring apparatus 10 is maintained at a predefined distance with respect to the bulkhead 28 along the specified trajectory 30. Ultimately, compliance with the planned route is regulated in this way. Thus the actual trajectory 32 which is in fact followed by the measuring apparatus 10 can be kept as close as possible to the specified trajectory 30.

[0042] Particularly reliable and reproducible measurement is accomplished by maintaining this trajectory and thus the specified parameters. In particular, quality assured recording of the structure can be ensured this way. For this, and influence function which describes the influence of the parameter on quality is defined for each of the parameters.

[0043] Additional parameters can be incorporated in route planning. In particular, these parameters can also be regulated in the inventive manner such that the quality reference value is achieved. Along with the distance of the sensors and thus of the measuring apparatus from the bulkhead as already described, this can also be the orientation of the sensors with respect to the bulkhead. For instance, the speed or acceleration of the bearing platform and orientation of the bearing platform can also comprise such parameters. Specified values are defined initially for the parameters to be regulated based on empirical values or estimated values. Referring to FIG. 3, a trajectory 34 to be followed is defined as part of route planning based on these specified values. This can subdivide an area of movement for the bearing platform into sectors 36 of various measurement quality around the bulkhead, as seen in FIG. 3. The top view in FIG. 3 shows the sectors 36 as square area elements. In the present case, the sectors are divided into various measurement qualities in a binary manner, specifically for sufficient quality on one hand and insufficient quality on the other. The specified quality reference value can be achieved in the sectors with sufficient quality. The trajectory 34 is set in the course of planning the route such that as far as possible only or at least as many sectors as possible with sufficient measurement quality are passed through.

[0044] For example, as already mentioned, the distance of the measuring apparatus with respect to the bulkhead and the orientation of the measurement sensors with respect to the bulkhead can be incorporated as parameters influencing quality. In defining the trajectory, the attempt is made to achieve the highest possible total quality, for example to achieve a specified quality or a highest possible quality. Since the objective of this is to achieve a particular quality overall via all parameters, it can be expedient, at least in sections, to specify a reference value for one of the parameters which is rather suboptimal insofar as this allows an optimal reference value to be specified for another parameter. For example, by varying the distance of the measuring apparatus with respect to the structure along the trajectory as shown in FIG. 3. This can be expedient, because perhaps only in this way can a desired orientation of the sensors with respect to the bulkhead surface be ensured. In particular, this can possibly ensure that the sensors comprised as lasers scanners impinge a beam path perpendicularly upon the structure's surface.

[0045] In accordance with the invention, these parameters can be regulated during the measurement run such that the specified quality reference value is achieved. For example, a resolution of 2 cm on the bulkhead 28 can be specified as a quality reference value. Then the quality characteristic is therefore the resolution of the structural data. This resolution can be achieved up to a maximum spacing of 5 m, for example, between measurement sensor 18 and bulkhead 28, but at a greater distance that can no longer be ensured in some circumstances. If, for example, the bearing platform 12 were to drift farther than 5 m from the bulkhead 28 due to wind and current, the bearing platform 12 can be brought closer to the bulkhead 28 again by changing the azimuthal direction angle, doing so in fact until the resolution of 2 cm or better is once again achieved. Thus the distance between bulkhead 28 and measurement sensor 18 can be regulated such that the quality reference value is achieved.

[0046] A structure to be investigated can also be scanned in multiple runs. As seen in FIG. 4, the bulkhead 28 underwater and a water body substrate 40 can be scanned by orienting the sensor 16 differently. Thus three measurement runs can be provided, in which a section of the bulkhead 28 situated farther above is measured in a first measurement run, the section of bulkhead thereunder is measured in a second measurement run, and finally the adjacent area of the water body substrate is measured in the third run. Regulation of the parameters influencing the measurement quality can take place in the inventive manner for all these runs.