SYSTEM AND METHOD FOR AUTONOMOUSLY POSITIONING A CAMERA OF A SEWER INSPECTION AND/OR MAINTENANCE SYSTEM

Abstract

A sewer inspection or maintenance system is provided having a sensor system with which at least three distances between a predetermined first point in the sewer pipe and the sewer wall of the sewer pipe are detected. The system has a processing unit adapted for determining a diameter of the sewer pipe and a predetermined second point in the sewer pipe based on the detected distances, and for determining a horizontal offset and a vertical offset between the predetermined first point and the predetermined second point based on the determined diameter and the detected distances. The system also has a positioning unit which is adapted to correct the position of an inspection unit in the sewer pipe by the two offsets. A corresponding method is provided as well.

Claims

1. A sewer inspection and/or maintenance system, at least comprising: a sensor system(S), which is adapted to detect at least three distances (d1; d2; d3) between a predetermined first point (P) in the sewer pipe and the sewer wall (W) of the sewer pipe, wherein the at least three distances are detected starting from the predetermined first point in different directions relative to the sewer wall, a processing unit (VE), which is adapted for: determining a diameter (d) of the sewer pipe and a predetermined second point (C) in the sewer pipe, preferably the center point of the sewer pipe, based on the distances (d1; d2; d3) detected by the sensor system, and determining a horizontal offset (?X) and a vertical offset (?Y) between the predetermined first point (P) and the predetermined second point (C) of the sewer pipe based on the determined diameter (d) and the detected distances (d1; d2; d3), and a positioning unit (H), which is operatively coupled to the processing unit and which is adapted to correct the position of an inspection unit in the sewer pipe by the horizontal offset (?X) and by the vertical offset (?Y).

2. The system according to claim 1, wherein the inspection unit is a camera and wherein the predetermined first point (P) is the center point of a lens of the camera.

3. The system according to claim 1, wherein the inspection unit is arranged on the positioning unit and wherein the positioning unit has a first actuating device, which is adapted to move the inspection unit by the horizontal offset (?X), and a second actuating device, which is adapted to move the inspection unit by the vertical offset (?Y).

4. The system according to claim 1, wherein the positioning unit is a lifting arm, at the free end of which the inspection unit is arranged, wherein preferably the free end of the positioning unit is movable in the vertical and horizontal directions.

5. A method for autonomously positioning an inspection unit in a sewer pipe, wherein the method comprises: a first step (S1) for detecting at least three distances (d1; d2; d3) between a predetermined first point (P) in the sewer pipe and the sewer wall of the sewer pipe, wherein the at least three distances are detected starting from the predetermined first point in different directions to the sewer wall, a second step (S2) for determining a diameter (d) of the sewer pipe and a predetermined second point (C) in the sewer pipe, preferably the center point of the sewer pipe, wherein the diameter and the predetermined second point are determined based on the detected distances (d1; d2; d3), a third step (S3) for determining a horizontal offset (?X) and a vertical offset (?Y) between the predetermined first point (P) and the predetermined second point (C) of the sewer pipe based on the determined diameter (d) and the detected distances (d1; d2; d3), and a fourth step (S4) for correcting the position of the inspection unit in the sewer pipe by the horizontal offset (?X) and by the vertical offset (?Y).

6. The method according to claim 5, wherein the inspection unit is a camera and wherein the center point of a lens of the camera is used as the predetermined first point (P).

7. The method according to claim 6, wherein a positioning unit is provided for correcting the position of the inspection unit in the sewer pipe, wherein the positioning unit has a first adjusting device, with which the inspection unit is moved by the horizontal offset (?X), and a second actuating device, with which the inspection unit is moved by the vertical offset (?Y).

8. The method according to claim 5, wherein a sensor system is used for detecting the at least three distances (d1; d2; d3).

9. The method according to claim 8, wherein the sensor system(S) is arranged offset by a predetermined second horizontal offset (?X2) and by a predetermined second vertical offset (?Y2) from the predetermined first point (P) outside the inspection unit, wherein prior to the fourth step (S4) the horizontal offset (?X) is corrected by the second horizontal offset (?X2) and the vertical offset (?Y) is corrected by the second vertical offset (?Y2).

10. The method according to claim 5, wherein the first step (S1), the second step (S2), the third step (S3) and the fourth step (S4) are carried out at regular intervals, preferably continuously, in order to correct the position of the inspection unit in the sewer pipe at regular intervals, preferably continuously.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0037] Further details and features of the invention as well as specific, particularly advantageous exemplary embodiments of the invention are apparent from the following description in conjunction with the drawings. In the figures:

[0038] FIG. 1 shows a schematic inspection system according to the invention in a sewer (side view);

[0039] FIG. 2 shows a schematic inspection system according to the invention in a sewer (view from the front); and

[0040] FIG. 3 shows a schematic representation of a point P to be corrected in a sewer, for illustrating the method according to the invention; and

[0041] FIG. 4 a schematic representation of a point P to be corrected in a sewer, for illustrating an alternative embodiment of the method according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0042] FIG. 1 shows a side view of a schematic inspection system according to the invention in a sewer that is bounded by the sewer wall W. FIG. 2 shows a view from the front of a schematic inspection system according to the invention in a sewer.

[0043] A crawler F of an inspection system, on which a lifting unit H is arranged, is located in the sewer. A camera K (or a camera head), which can be designed as an image or video camera, is arranged at the free end of the lifting unit H.

[0044] FIG. 1 and FIG. 2 show the center C of the sewer. As can be seen in FIG. 1, the camera is arranged or positioned above the center C of the sewer. In FIG. 2, the camera is arranged below the center C of the sewer. In both cases, the accommodation of the camera is not carried out in the center of the pipe.

[0045] A sensor system S, which is arranged here on the camera K, is provided for aligning the camera K in the center of the pipe or sewer. The sensor system S is coupled here via a data line to a processing unit VE, which is arranged in the crawler. However, the processing unit VE can also be arranged in the camera or in the sensor system itself. However, the coupling of the sensor system S to the processing unit VE can also be carried out wirelessly; i.e., data provided by the sensor system can also be transferred wirelessly to the processing unit VE.

[0046] The sensor system S is adapted to detect at least three distances d1; d2; d3 between a predetermined first point P (which here is the center point of the camera lens) in the sewer pipe and the sewer wall W of the sewer pipe, wherein the at least three distances are detected starting from the predetermined first point P in different directions relative to the sewer wall, as described in more detail in FIG. 3. The sensor system S can have laser, ultrasonic or infrared sensors, which are used to determine the distances to the sewer wall. Other sensor technologies can also be used within the meaning of the invention.

[0047] In FIG. 1 and FIG. 2, the predetermined point P, to which the three distances are detected, is located outside the sensor system S. According to the invention, the distances are detected in relation to the predetermined point P; i.e., the offset of the sensor system to the predetermined point P is taken into account when detecting the distances, as described in more detail with reference to FIG. 4.

[0048] The detected distances d1; d2; d3 are transferred to the processing unit VE, which uses them to calculate the diameter d of the sewer pipe, as also explained in more detail with reference to FIG. 3.

[0049] From the detected distances d1; d2; d3 and the calculated diameter d, the processing unit VE determines a predetermined second point C in the sewer pipe, which is preferably the center point of the sewer pipe. However, it can also be any other point in the sewer pipe if, for example, the camera is to always be aligned at this other point.

[0050] Based on the determined diameter d and the detected distances d1; d2; d3, the processing unit VE determines a horizontal offset ?X and a vertical offset ?Y between the predetermined first point P and the predetermined second point C of the sewer pipe. If the predetermined second point C is the center of the sewer pipe, the processing unit VE determines a horizontal offset ?X and a vertical offset ?Y by which the camera position in the sewer must be corrected in order to be aligned in the center of the sewer or pipe.

[0051] The two offsets ?X and ?Y are made available to a positioning unit H, which in this case is a lifting arm, which then carries out a movement corresponding to the two offsets (up/down and/or left/right), as a result of which the camera arranged on the positioning unit is aligned in the center of the sewer or pipe. After alignment, the predetermined first point P and the predetermined second point C coincide.

[0052] With the example shown in FIG. 2, the horizontal offset is zero and the vertical offset is greater than zero. That is, the positioning unit H only needs to be moved upwards in order to position the camera in the center of the pipe.

[0053] In principle, however, the positioning unit is designed so that the camera can move upwards, downwards, to the left and to the right. For this purpose, the positioning unit can have corresponding actuating means (for example, servomotors).

[0054] FIG. 3 shows a schematic representation of a point P to be corrected in a sewer, for illustrating the method according to the invention.

[0055] The method according to the invention substantially comprises four steps: [0056] Step S1: Detection of at least three distances d1; d2; d3 between a predetermined first point P in the sewer pipe and the sewer wall W of the sewer pipe, wherein the at least three distances are detected starting from the predetermined first point P in different directions relative to the sewer wall.

[0057] Step S2: Determining the diameter d of the sewer pipe and a predetermined second point C in the sewer pipe based on the distances d1; d2; d3 detected in step S1. The predetermined second point C can be the center point of the sewer pipe. The diameter and the second point C can be determined using the circumcircle of the triangle defined by the three points (given by the three distances). Other calculation rules can also be used within the meaning of the invention. [0058] After step S2, the second point C (for example, the center point of the pipe), the three distances d1; d2; d3 to the sewer wall W and thus also the first point P in the sewer pipe are known. [0059] Step S3: Based on the determined diameter d and the detected distances d1; d2; d3, i.e., based on the two points P and C, a horizontal offset ?X and a vertical offset ?Y between the point P and the point C can now be calculated, wherein the two offsets specify correction values by which the position of the camera in the sewer must be corrected so that the camera is aligned in the center of the pipe. [0060] Step S4: Correction of the position of the inspection unit (for example, the camera) in the sewer pipe by the horizontal offset ?X and by the vertical offset ?Y. The two offsets are made available to the positioning unit, which can then carry out or carries out the corresponding corrections in the X (left/right) and Y (up/down) directions.

[0061] In FIG. 3, point P represents the optical center (optical axis) of the camera and point C represents the center of the sewer. With the method according to the invention, the optical center P of the camera is thus displaced to the center C of the sewer, so that the two points P and C coincide.

[0062] FIG. 4 shows a schematic representation of a point P to be corrected in a sewer, for illustrating an alternative embodiment of the method according to the invention.

[0063] In the representation shown in FIG. 4, it is assumed that the sensor system S is not arranged on the camera but is arranged, for example, on the crawler. The sensor system is arranged on the crawler such that it can detect the three distances d1; d2; d3. In FIG. 4, point P represents the optical center (optical axis) of the camera, point C the center of the sewer and point S the position of the sensor system. Therefore, the sensor system is arranged offset from point P by a second horizontal offset ?X2 and a second vertical offset ?Y2. These two offsets ?X2 and ?Y2 must be taken into account when calculating the two offsets ?X and ?Y, so that the camera is positioned correctly at point C. Without taking into account the two offsets ?X2 and ?Y2, the camera would be positioned offset to point C by the offsets ?X2 and ?Y2 after the correction of the camera position.

[0064] During an inspection, the relative position of the camera to the sensor system can change in a system with which the sensor system does not move with the camera. This means that the offsets ?X2 and ?Y2 can change during an inspection. However, the changes to these offsets ?X2 and ?Y2 are known to the processing unit VE, since the processing unit VE itself corrects the position of the camera. Thus, the processing unit VE can take into account the correct offsets ?X2 and ?Y2 at any time when calculating the two offsets ?X and ?Y. In the event that the camera position is changed manually, for example, these changes must be made known to the processing unit VE in order to be able to calculate the correct offsets ?X2 and ?Y2.

[0065] In one embodiment of the invention, the two offsets ?X and ?Y can be determined continuously. As soon as one of the two or both offsets ?X, ?Y are different from zero, a correction of the positioning of the camera can be performed. This ensures that the camera is positioned or aligned in the center of the pipe during the entire inspection process.

[0066] Examples have been described above with which the correction of the positioning of the camera is carried out so that the camera is always aligned in the center of the pipe, i.e., is always located at point C.

[0067] However, according to one aspect of the invention, it is also possible to automatically position the camera so that it is always located outside the center C of the pipe by a specific offset. This specific offset only needs to be taken into account when calculating the two offsets ?X and ?Y. This makes it possible, for example, to always position the camera 20 cm to the left and 30 cm above the pipe center point C during an inspection process.

[0068] The system according to the invention uses a sensor-based diameter measurement to calculate the necessary vertical and horizontal adaptations or corrections to the camera position, which are transmitted to a mechanical element for supporting the camera movement, such as a lifting unit.

[0069] The invention thus provides an autonomous camera positioning system for sewer inspections. The method according to the invention simplifies the positioning process, eliminates the need for manual calculations and adaptations and increases the accuracy and efficiency of the inspection.

[0070] Special advantages of the invention are: [0071] Improved accuracy: The sensor-based diameter measurement and automatic calculations reduce the risk of human error, which leads to more accurate camera positioning and better inspection results. [0072] Consistency: The invention standardizes the camera positioning process and provides consistent results for different inspection scenarios and operators, making it easier to compare inspection results from different inspections or inspection teams. [0073] Time efficiency: The elimination of manual calculations and adaptations speeds up the camera positioning process, saving time and reducing labor costs, in particular on large or complex pipe inspection projects. [0074] Less reliance on operator skill: Fully autonomous positioning of the camera reduces reliance on operator skill and experience, which leads to more consistent inspection results. [0075] Increased adaptability: The invention makes it possible to work with different sensor types and can be easily adapted to different pipe sizes and shapes. [0076] Reduced risk of equipment damage: Accurate and precise camera positioning minimizes the risk of damage to the camera or other inspection equipment, which can reduce repair or replacement costs and project delays.