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

Description

Field of invention

[0001] The invention relates to a sewer inspection and / or maintenance system adapted to autonomously position a camera in a sewer pipe. The invention further relates to a correspondingly designed method. Background of the invention

[0002] In sewer inspection and / or maintenance systems, imaging devices (cameras or video cameras) are used to record the interior of a pipe or sewer. Hereinafter, the imaging device, camera, and video camera are collectively referred to as the camera. It is advantageous to position the camera centrally within the pipe to obtain optimal inspection results.

[0003] With conventional pipe inspection systems, the camera is positioned manually in the center of the pipe. For example, before the inspection, the camera can be mounted on a carriage so that, given a known pipe or sewer diameter, it is positioned largely in the center of the pipe. However, a disadvantage of this method is that if there are deposits on the pipe bed or if the pipe diameter changes, the camera is no longer positioned in the center of the pipe.

[0004] In inspection systems where the camera is mounted, for example, on a lifting unit of a crawler, the operator can control the lifting unit during an inspection to align the camera as closely as possible to the center of the pipe. However, this is complex and prone to errors, and the operator must consider factors such as the crawler's wheel diameter, the distance between the wheels, the pipe diameter, the camera size, and the dimensions of the lifting unit. This can significantly impair and delay the quality of an inspection. Furthermore, when multiple inspections are performed consecutively in the same sewer, comparing inspection results, especially image and / or video recordings, becomes difficult if the images and / or videos were taken from different positions within the pipe. Correctly positioning a camera in the sewer requires specialized skills and considerable experience from the operator.Furthermore, there is a risk that the camera will collide with the channel wall during the positioning process, which can lead to damage to the camera or even to the entire inspection system.

[0005] However, if an inspection unit other than a camera needs to be aligned in the center of the pipe, even the possibility of "visual" alignment is eliminated. Such inspection units must therefore be aligned accordingly before inspection, with the disadvantages described above. The relevant prior art is DE 20 2013 100 437 U1. Object of the invention

[0006] The object of the invention is therefore to provide solutions that enable simpler, faster and at the same time safer positioning of an inspection unit in the channel. Inventive solution

[0007] This problem is solved by a system and a method according to the independent claims. Advantageous embodiments are specified in the respective dependent claims.

[0008] A sewer inspection and / or maintenance system will therefore be provided, which includes at least the following: a sensor system adapted to detect at least three distances between a predetermined first point in the sewer pipe and the pipe wall, wherein the at least three distances are detected from the predetermined first point in different directions towards the pipe wall; a processing unit adapted to determine, based on the distances detected by the sensor system, a diameter of the sewer pipe and a predetermined second point in the sewer pipe, preferably the center point of the sewer pipe; to determine, based on the determined diameter and the detected distances, a horizontal offset and a vertical offset between the predetermined first point and the predetermined second point of the sewer pipe; and a positioning unit that is operationally coupled with the processing unit and is adapted toto correct the position of an inspection unit in the sewer pipe to compensate for horizontal and vertical offsets.

[0009] This allows a camera or other inspection unit to be precisely aligned at a predetermined position within the sewer pipe, for example, in the center, without manual intervention. The advantage here is that the alignment can be accomplished much faster and more accurately than with manual alignment.

[0010] If several inspection processes are carried out consecutively, this also ensures that, for example, image and / or video recordings are always taken from the exact same position (e.g., from the center of the channel), so that the consecutive image and / or video recordings can be compared particularly easily and accurately. This also applies if different camera systems and / or different crawler vehicles are used for the various inspection processes.

[0011] The inspection unit can be a camera, where the predetermined first point is the center point of one of the camera's lenses. This allows the camera's optical axis to be aligned with the center of the pipe.

[0012] The inspection unit, such as the camera, can be arranged on the positioning unit, wherein the positioning unit has a first positioning device adapted to move the inspection unit by the horizontal offset, and a second positioning device adapted to move the inspection unit by the vertical offset.

[0013] In one embodiment of the invention, the positioning unit can be 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 direction in order to correct the position of the inspection unit in the vertical and horizontal direction.

[0014] Furthermore, a method for autonomously positioning an inspection unit in a sewer pipe is provided, the method comprising at least: a first step for detecting at least three distances between a predetermined first point in the sewer pipe and the pipe wall, wherein the at least three distances are detected starting from the predetermined first point in different directions to the pipe wall; a second step for determining a diameter of the sewer pipe and a predetermined second point 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; a third step for determining a horizontal offset and a vertical offset between the predetermined first point and the predetermined second point of the sewer pipe, wherein the third step is carried out based on the determined diameter and the detected distances.and a fourth step to correct the position of the inspection unit in the sewer pipe by the horizontal offset and the vertical offset.

[0015] To correct the position of the inspection unit in the sewer pipe, a positioning unit can be provided, wherein the positioning unit has a first positioning device with which the inspection unit is moved by the horizontal offset, and a second positioning device with which the inspection unit is moved by the vertical offset.

[0016] A sensor system can be used to detect at least three distances.

[0017] The sensor system can be arranged outside the inspection unit offset by a predetermined second horizontal offset and a predetermined second vertical offset from the predetermined first point (this also applies to the system described above), wherein before the fourth step the horizontal offset by the second horizontal offset and the vertical offset by the second vertical offset to be corrected.

[0018] This means that the sensor system does not necessarily have to be positioned directly on the camera or integrated into the camera.

[0019] In one embodiment of the invention, the first step, the second step, the third step and the fourth step can be 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.

[0020] This ensures that the camera is always aligned in the center of the pipe throughout the entire inspection process, even if the pipe diameter changes. Brief description of the characters

[0021] Further details and features of the invention, as well as specific, particularly advantageous embodiments of the invention, will become apparent from the following description in conjunction with the drawing. It shows: Fig. 1 a schematic inspection system according to the invention in a channel (side view); Fig. 2 a schematic inspection system according to the invention in a channel (front view); and Fig. 3 a schematic representation of a point P to be corrected in a channel, to illustrate the method according to the invention; and Fig. 4 a schematic representation of a point P to be corrected in a channel, to illustrate an alternative embodiment of the method according to the invention. Detailed description of the invention

[0022] Fig. 1 Figure 1 shows a schematic inspection system according to the invention in a channel which is bounded by the channel wall W in a side view. Fig. 2 A schematic inspection system according to the invention is shown in a front view in a channel.

[0023] A carriage F of an inspection system is located in the channel, to which a lifting unit H is attached. A camera K (or a camera head), which can be configured as a still or video camera, is located at the free end of the lifting unit H.

[0024] Shown are Fig. 1 and Fig. 2 the channel center C. As in Fig. 1 As can be seen, the camera is arranged or positioned above the center of channel C. Fig. 2 The camera is positioned below the center of the channel (C). In both cases, the camera images are not taken from the center of the pipe.

[0025] A sensor system S, located on the camera K, is provided for aligning the camera K in the center of the pipe or channel. The sensor system S is connected via a data line to a processing unit VE, which is located in the vehicle. However, the processing unit VE can also be located in the camera or in the sensor system itself. The connection between the sensor system S and the processing unit VE can also be wireless, meaning that data provided by the sensor system can be transmitted wirelessly to the processing unit VE.

[0026] 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 of the camera lens) in the sewer pipe and the pipe wall W of the sewer pipe, wherein the at least three distances starting from the predetermined first point P are detected in different directions to the pipe wall, as shown in Fig. 3 The sensor system S can include laser, ultrasonic, or infrared sensors used to determine the distances to the channel wall. Other sensor technologies can also be used in accordance with the invention.

[0027] In Fig. 1 and Fig. 2 The predetermined point P, to which the three distances are measured, is located outside the sensor system S. According to the invention, the distances are measured relative to the predetermined point P; that is, the offset of the sensor system to the predetermined point P is taken into account when measuring the distances, as with reference to Fig. 4 will be described in more detail.

[0028] The recorded distances d1; d2; d3 are transferred to the processing unit VE, which calculates the diameter d of the sewer pipe from them, as well as with reference to Fig. 3 explained in more detail.

[0029] From the measured 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 always to be aligned with this other point.

[0030] Based on the determined diameter d and the measured distances d1, d2, and d3, the processing unit VE calculates a horizontal offset ΔX and a vertical offset ΔY 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 calculates a horizontal offset ΔX and a vertical offset ΔY by which the camera position in the sewer must be corrected to be aligned with the center of the sewer or pipe.

[0031] The two offsets ΔX and ΔY are provided to a positioning unit H, which in this case is a lifting arm. The positioning unit then performs a movement corresponding to the two offsets (up / down and / or left / right), thereby aligning the camera mounted on the positioning unit with the center of the channel or pipe. After alignment, the predetermined first point P and the predetermined second point C coincide.

[0032] At the in Fig. 2 In the example shown, the horizontal offset is zero and the vertical offset is greater than zero. This means that the positioning unit H only needs to be moved upwards to position the camera in the center of the pipe.

[0033] In principle, the positioning unit is designed so that the camera can move up, down, left, and right. The positioning unit can incorporate appropriate actuators (e.g., servo motors) for this purpose.

[0034] Fig. 3 Figure 1 shows a schematic representation of a point P to be corrected in a channel, to illustrate the method according to the invention.

[0035] The method according to the invention essentially comprises four steps: Step S1: Detecting at least three distances d1; d2; d3 between a predetermined first point P in the duct pipe and the duct wall W of the duct pipe, wherein the at least three distances are detected starting from the predetermined first point P in different directions to the duct wall.

[0036] Step S2: Determining the diameter d of the duct pipe and a predetermined second point C within the duct pipe based on the distances d1, d2, and d3 determined in step S1. The predetermined second point C can be the center point of the duct 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 methods can also be used in accordance with the invention.

[0037] After step S2, the second point C (e.g. the center of the pipe), the three distances d1; d2; d3 to the channel wall W and thus also the first point P in the channel pipe are known.

[0038] Step S3: Based on the determined diameter d and the recorded distances d1; d2; d3, i.e. based on the two points P and C, a horizontal offset ΔX and a vertical offset ΔY between point P and point C can now be calculated, where the two offsets are given as correction values ​​by which the position of the camera in the channel must be corrected so that the camera is aligned in the center of the pipe.

[0039] Step S4: Correcting the position of the inspection unit (e.g., the camera) in the sewer pipe by the horizontal offset ΔX and the vertical offset ΔY. These two offsets are provided to the positioning unit, which can then perform the corresponding corrections in the X (left / right) and Y (up / down) directions.

[0040] In Fig. 3 Point P represents the optical center (optical axis) of the camera, and point C represents the center of the channel. According to the inventive method, the optical center P of the camera is thus shifted to the center C of the channel, so that the two points P and C coincide.

[0041] Fig. 4 Figure 1 shows a schematic representation of a point P to be corrected in a channel, to illustrate an alternative embodiment of the method according to the invention.

[0042] At the in Fig. 4 The illustration shows that the sensor system S is not located on the camera, but, for example, on the vehicle. The sensor system is positioned on the vehicle in such a way that it can detect the three distances d1, d2, and d3. Fig. 4Point P represents the optical center (optical axis) of the camera, point C the center of the channel, and point S the position of the sensor system. The sensor system is therefore offset from point P by a second horizontal offset ΔX2 and a second vertical offset ΔY2. These two offsets ΔX2 and ΔY2 must be taken into account when calculating the two offsets ΔX and ΔY to ensure the camera is correctly positioned at point C. Without considering these two offsets ΔX2 and ΔY2, the camera would be positioned offset from point C by these ΔX2 and ΔY2 after the camera position correction.

[0043] During an inspection, in a system where the sensor system does not move with the camera, the relative position of the camera to the sensor system can change. This means that the offsets ΔX2 and ΔY2 can change during an inspection. However, the processing unit (VE) is aware of these changes because the VE itself corrects the camera's position. Therefore, the VE can always consider the correct offsets ΔX2 and ΔY2 when calculating the offsets ΔX and ΔY. If the camera position is changed manually, for example, these changes must be communicated to the VE in order to calculate the correct offsets ΔX2 and ΔY2.

[0044] In one embodiment of the invention, the two offsets ΔX and ΔY can be continuously determined. As soon as one or both offsets ΔX, ΔY are different from zero, the camera's positioning can be corrected. This ensures that the camera is positioned or aligned centrally within the pipe throughout the entire inspection process.

[0045] The examples described above show how the positioning correction is carried out so that the camera is always aligned with the center of the pipe, i.e., is always located at point C.

[0046] According to one aspect of the invention, it is also possible to automatically position the camera so that it is always located a certain distance outside the pipe center C. This specific offset simply needs to be taken into account when calculating both offsets ΔX and ΔY. For example, this makes it possible to always position the camera 20 cm to the left and 30 cm above the pipe center C during an inspection process.

[0047] The system according to the invention uses sensor-based diameter measurement to calculate the required vertical and horizontal adjustments or corrections of the camera position, which are transmitted to a mechanical element to support the camera movement, such as a lifting unit.

[0048] 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 adjustments, and increases the accuracy and efficiency of the inspection.

[0049] The invention offers particular advantages: Improved accuracy: Sensor-based diameter measurement and automatic calculations reduce the risk of human error, resulting in more accurate camera positioning and better inspection results. Consistency: The invention standardizes the camera positioning process and delivers consistent results for different inspection scenarios and operators, facilitating the comparison of inspection results from different inspections or inspection teams. Time efficiency: Eliminating manual calculations and adjustments speeds up the camera positioning process, saving time and reducing labor costs, especially in large or complex pipe inspection projects. Reduced dependence on operator skills: Fully autonomous camera positioning reduces dependence on the operator's skills and experience, leading to more consistent inspection results.Increased adaptability: The invention allows for the use of various sensor types and can be easily adapted to different pipe sizes and shapes. Reduced risk of equipment damage: Accurate and precise camera positioning minimizes the risk of damage to the camera or other inspection equipment, thereby reducing repair or replacement costs and project delays.

Claims

1. A sewer inspection and / or maintenance system comprising at least: - a sensor system (S) 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 from the predetermined first point in different directions to the sewer wall, characterized in that the system further comprises: - a processing unit (VE) adapted to - determine 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, - based on the determined diameter (d) and the detected distances (d1; d2; d3), to determine a horizontal offset (ΔX) and a vertical offset (ΔY) between the predetermined first point (P) and the predetermined second point (C) of the sewer pipe, and - a positioning unit (H) that is operatively coupled to the processing unit and is adapted to correct the position of an inspection unit in the sewer pipe by the horizontal offset (ΔX) and the vertical offset (ΔY).

2. 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. System according to claim 1, wherein the inspection unit is arranged on the positioning unit and wherein the positioning unit comprises - a first actuator adapted to move the inspection unit by the horizontal offset (ΔX), and - a second actuator adapted to move the inspection unit by the vertical offset (ΔY).

4. 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. Method for autonomously positioning an inspection unit in a sewer pipe, wherein the method comprises at least: - a first step (S1) of 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 from the predetermined first point in different directions toward the sewer wall, characterized in that the method comprises: - 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, based on the determined diameter (d) and the detected distances (d1; d2; d3), a horizontal offset (ΔX) and a vertical offset (ΔY) between the predetermined first point (P) and the predetermined second point (C) of the sewer pipe, and - a fourth step (S4) for correcting the position of the inspection unit in the sewer pipe by the horizontal offset (ΔX) and by the vertical offset (ΔY).

6. Method according to the preceding claim, 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. 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 comprises - a first actuator for moving the inspection unit by the horizontal offset (ΔX), and - a second actuator for moving the inspection unit by the vertical offset (ΔY).

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

9. Method according to claim 8, wherein the sensor system (S) is arranged outside the inspection unit at a predetermined second horizontal offset (ΔX2) and at a predetermined second vertical offset (ΔY2) from the predetermined first point (P), wherein before the fourth step (S4) - the horizontal offset (ΔX) is offset by the second horizontal offset (ΔX2) and - the vertical offset (ΔY) is corrected by the second vertical offset (ΔY2).

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