AU2016102406A4

AU2016102406A4 - An unmanned ground vehicle for inspecting confined infrastructures

Info

Publication number: AU2016102406A4
Application number: AU2016102406A
Authority: AU
Inventors: Jaeho Lee
Original assignee: Smart Infrastructure Asset Management Australia Res And Development Pty Ltd
Current assignee: Smart Infrastructure Asset Management Australia Research And Development Pty Ltd
Priority date: 2015-04-16
Filing date: 2016-04-12
Publication date: 2019-05-09
Anticipated expiration: 2024-04-12
Also published as: AU2016202254A1

Abstract

The present invention relates to an unmanned ground vehicle (UGV) for inspecting infrastructure. The UGV includes a navigation system including one or more sensors for sensing the infrastructure, and for navigating the UGV relative to the sensed infrastructure. An inspection system is also provided for inspecting the infrastructure. Advantageously, the UGV may navigate along and inspect all sizes of culverts. The UGV may be accurately and repeatedly navigated relative to the sensed culverts during inspection using the localized onboard sensors, and preferably need not rely on GPS signals which are often unreliable in confined locations and less accurate than the sensors. Preferably, the navigation is automated thereby improving inspection accuracy and repeatability.

Description

COMPLETE SPECIFICATION STANDARD PATENT

AN UNMANNED GROUND VEHICLE FOR INSPECTING CONFINED INFRASTRUCTURES

The following statement is a full description of this invention including the best method of performing it known to me:

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AN UNMANNED GROUND VEHICLE FOR INSPECTING CONFINED INFRASTRUCTURES

TECHNICAL FIELD [0001] The present invention relates to an unmanned ground vehicle (UGV) for inspecting infrastructure. The present invention has particular, although not exclusive application to inspecting culverts and tunnels, and other like confined infrastructures.

BACKGROUND [0002] The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

[0003] Culverts, such as those used under roadways, are periodically visually inspected for defects by responsible authorities.

[0004] Several limitations have been identified with this manual approach. These limitations include: (1) visual inspections being subjective, depending upon the particular inspector and not always reliable; (2) the entire manual process being costly and time-consuming; (3) a number of safety risks are associated with field inspectors entering narrow culverts including toxic chemicals; and (4) inspections require experienced and highly trained personnel. At present, there is a shortage of inspectors that meet the required level of expertise.

[0005] Furthermore, inspectors are often impeded from reliably inspecting hard-toreach locations within culverts. Additionally, culvert defects such as cracks, corrosion and spalling are not measured accurately over time which leads to an imprecise inspection history.

[0006] The preferred embodiment provides a means to inspect comprehensive range of culverts, with greater accuracy and repeatability.

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SUMMARY OF THE INVENTION [0007] According to one aspect of the present invention, there is provided an unmanned ground vehicle (UGV) for inspecting infrastructure, the UGV includes:

a navigation system including one or more sensors for sensing the infrastructure, and for navigating the UGV relative to the sensed infrastructure; and an inspection system for inspecting the infrastructure.

[0008] Advantageously, the UGV may navigate along and inspect all sizes of culverts. The UGV may be accurately and repeatedly navigated relative to the sensed culverts during inspection using the localized onboard sensors, and preferably need not rely on GPS signals which are often unreliable in confined locations and less accurate than the sensors. Preferably, the navigation is automated thereby improving inspection accuracy and repeatability.

[0009] The navigation system may use the infrastructure as a navigation reference. The sensors may include a laser scanner for sensing the position of the UGV relative to the infrastructure. The scanner may be able to scan through 360°.

[00010] The UGV may include a distance sensor for sensing the travel distance of the UGV. The distance sensor may include a laser range finder.

[00011] The inspection system may include a camera configured to capture images of an interior wall of the infrastructure. The inspection system may include a gimbal to which the camera can be mounted. The camera may be able to rotate, optionally through 360°. The camera may be configured to capture images at predefined angles. The inspection system may include a height adjustment mechanism for adjusting the height of the camera.

[00012] The UGV may further include a lighting system for lighting an interior wall of the infrastructure. The lighting system may include one or more light emitting diodes (LEDs).

[00013] The navigation system may include a controller for controlling motion of the UGV whereby the UGV performs an inspection of the infrastructure at one location, prior to moving to a subsequent location for inspection. The locations may be located at fixed

2016102406 12 Apr 2016 intervals. The intervals may be about 50cm. The controller may control the UGV to move along the centre of the infrastructure.

[00014] The UGV motion may be unconstrained, and not constrained to a track, wire or other defined path. The UGV may include a chassis relative to which two driving tracks are mounted.

[00015] According to another aspect of the present invention, there is provided an infrastructure inspection system, the inspection system including:

the UGV; and a control system for controlling the UGV.

[00016] The system may include a reference device fixed relative to the infrastructure to facilitate navigation. The control system may be in wireless communication with the UGV.

[00017] According to another aspect of the present invention, there is provided a method for inspecting infrastructure with a unmanned ground vehicle (UGV), the method including the steps of:

sensing the infrastructure;

navigating the UGV relative to the sensed infrastructure; and inspecting the infrastructure.

[00018] The step of sensing may involve sensing the position of the UGV within the infrastructure.

[00019] The step of navigating may involve sensing the travel distance of the UGV. The step of navigating may involve navigating the UGV within and along the sensed infrastructure. The step of navigating may involve navigating the UGV along the centre of the infrastructure.

[00020] The step of inspecting may involve capturing images of an interior wall of the infrastructure. The method may further involve the step of lighting an interior wall of the infrastructure to facilitate capturing of the images. The location of the UGV may be associated with each captured image to facilitate inspection comparisons over time by comparing images at the same location. The step of inspecting may involve serial

2016102406 12 Apr 2016 inspection of the infrastructure at intervals. The step of inspecting may involve capturing images at predefined angles. The step of inspecting may involve adjusting the height of a camera. The method may involve piecing the images together.

[00021] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS [00022] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows:

[00023] Figure 1 a is a plan schematic view of a culvert inspection system in accordance with an embodiment of the present invention;

[00024] Figure 1 b is a front schematic view showing the unmanned ground vehicle (UGV) of the system of Figure 1 a; and [00025] Figure 2 is a flowchart of an inspection method performed using the system of Figure 1a.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [00026] According to an embodiment of the present invention, there is provided a culvert (i.e. infrastructure) inspection system 100 as shown in Figure 1a. The inspection system 100 includes an unmanned ground vehicle (UGV) 102 for inspecting a culvert 104, and a remote control system 106 for controlling the UGV 102. The control system 106 is in wireless communication with the UGV 102 via a radio-frequency link 108. The system 100 also includes a reference board 110 which is temporarily fitted to or near the mouth of the culvert to facilitate navigation of the UGV 102.

2016102406 12 Apr 2016 [00027] The UGV 102 includes a frontal navigation system 112. In turn, the navigation system 112 includes a laser sensor 114 for sensing the internal wall of the culvert 104, and for navigating the UGV 102 along the sensed culvert 104. The UGV 102 also includes an inspection system 116 for inspecting the sensed culvert 104.

[00028] Advantageously, the UGV 102 can navigate along and inspect the narrow culvert 104. The UGV 102 can be accurately and repeatedly navigated relative to the sensed culvert 104 during inspection using the onboard sensor 114, and preferably need not rely on GPS signals which are often unreliable in confined locations and less accurate than the sensors 114. The navigation is automated thereby improving inspection accuracy, and repeatability on different occasions. A detailed description of the UGV 102 is provided below.

[00029] The navigation system 112 effectively uses the culvert 104 as a navigation reference for controlling UGV motion. The laser sensor 114 is in the form of a laser scanner for scanning the internal wall of the culvert 104 and thereby sensing the location of the UGV 102 within the culvert 104. The laser sensor 114 is able to scan through a full 360° in the horizontal plane.

[00030] The navigation system 112 further includes a rear laser range finder 118 for sensing the travel distance of the UGV 102 from the temporary reference board 110 and into the culvert 104.

[00031] As can best be seen in Figure 1 b, the inspection system 116 includes a highresolution camera 120 configured to capture images of the cylindrical interior wall of the culvert 104. The inspection system 116 includes a gimbal 122 capable of rotation in two axes (i.e. pitch and roll) to which the camera 120 is mounted. The camera 120 is able to rotate through 360° in the vertical plane. The camera 120 is configured to capture images at predefined angles to effectively capture the entire internal wall in a piecemeal manner. The inspection system 116 also includes a height adjustment mechanism 124, in the form of a telescopic post variable between 0.6 and 2.5m, for adjusting the height of the camera 120 so that the internal wall of the culvert 104 falls within the vision envelope 126 of the camera 120. Ideally, the camera 120 is positioned at a height equidistant between the apex of, and floor within the culvert 104.

2016102406 12 Apr 2016 [00032] The UGV 102 also includes a lighting system 127, with low power consumption light emitting diodes (LEDs), for lighting the interior wall of the culvert 104 to facilitate better image capture.

[00033] The navigation system 112 also includes a controller for controlling motion of the UGV 102 whereby UGV 102 performs an inspection of the culvert 104 at one location, prior to moving to a subsequent location for further inspection. The inspection locations are at fixed intervals of about 50cm to facilitate capture of the whole visible wall, section by section.

[00034] The UGV motion is unconstrained, and not constrained to a track, wire or other defined path. Accordingly, the controller steers the UGV 102 to move along the centre of the culvert 104, in a lateral position equidistant from either side of the circular culvert 104, for correct and repeatable camera placement. The centering of the camera 102 assists with later image processing of the captured images.

[00035] The UGV 102 includes a base chassis 128 relative to which two movable driving tracks 130 are mounted.

[00036] An inspection method 200 for inspecting the culvert 104 with the UGV 102 is now described with reference to Figure 2.

[00037] Initially, at step 202, the UGV 102 enters the culvert 104. The reference board 110 is temporarily fastened to the mouth of the culvert 104. The camera 120 is adjusted to the required height based upon the height of the culvert 104 which is substantially uniform along its length.

[00038] At step 204, the navigation system 112 automatically senses the culvert 104 using the front laser sensor 114 and navigates the UGV 102 forward within the centre of the sensed culvert 104. The navigation system 112 automatically moves the UGV 102 forward serially at 50cm inspection intervals and senses the distance travelled from the reference board 110 using the laser range finder 118.

[00039] At each inspection interval, the UGV 102 automatically pauses to inspect the culvert 104. The inspection involves the camera 120 rotating through 360° to capture high-resolution images of the interior wall of the culvert 104 which is lit up with the

2016102406 12 Apr 2016 lighting system 127. The location of the UGV 102 is associated with each captured and stored image to facilitate inspection comparisons over time, by comparing images at the same location. The images are captured at predefined angles dependent upon the diameter of the culvert 104, from side to side, and later pieced together to form a panorama prior to image processing.

[00040] Upon completion of inspection at a predetermined inspection point, the UGV 102 automatically moves to the next inspection point and the inspection process is repeated.

[00041] At step 206, once the entire culvert 104 has been inspected at each inspection point, the UGV 102 exits from the other end of the culvert 104. A user can then export the captured images and associated locations from the UGV 102 to the controller 106 or another computer for detailed image processing inspection.

[00042] The foregoing inspection method 200 is both reliable and economical. The UGV 102 eliminates inconsistencies in inspection results that are caused from difficulty accessing confined infrastructure, as well as inspecting under low light conditions. The need for a certified inspector on site is also avoided, which can otherwise substantially cut into a budget and adversely affect long-term funding requirements. The inspector can instead verify the final condition rating of the culvert 104 once the defects have been analysed through image processing of the captured images.

[00043] The foregoing inspection method 200 is safer than manual inspection. The confines of a culvert 104 can typically be as small as 1.2 metres in height. Manual inspections of these structures pose risks to inspectors entering hazardous environments that may contain toxic chemicals. Replacing humans with the autonomous UGV 102 eliminates the need to perform safety checks prior to inspection, which can save time and cost.

[00044] The foregoing inspection method 200 also provides for whole structure analysis of the culvert 104. The section-by-section procedure used to acquire the images allows the entire surface of the structure to be analysed. This eliminates the chances of a culvert inspector overlooking crucial defects which can otherwise occur when conducting a manual inspection.

2016102406 12 Apr 2016 [00045] The foregoing inspection method 200 is readily repeatable. The UGV 102 can accurately return to the known position of any specified image, showing specific defects, to capture further images. This is beneficial when culverts undergo periodic inspections whereby images of defects at the same locations can be compared and consistently monitored over time.

[00046] A person skilled in the art will appreciate that many embodiments and variations can be made without departing from the ambit of the present invention.

[00047] In one embodiment, during inspection, a user can detect the other end of the culvert 104 by viewing real-time images from the camera 120 on the controller 106. The controller 106 can signal the navigation system 112 to automatically reverse the UGV 102 out from the culvert 104 using the laser sensor 114 and laser range finder 118.

[00048] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect.

[00049] Reference throughout this specification to One embodiment’ or ‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases ‘in one embodiment’ or ‘in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

Claims

The claims defining the invention are as follows:

1. An unmanned ground vehicle (UGV) for inspecting infrastructure, the UGV includes:

a navigation system including one or more sensors for sensing the infrastructure, and for navigating the UGV relative to the sensed infrastructure; and an inspection system for inspecting the infrastructure.
2. A UGV as claimed in claim 1, wherein the UGV is accurately and repeatedly navigated relative to sensed culverts during inspection using the sensors which are localized onboard, and preferably need not rely on GPS signals which are often unreliable in confined locations and less accurate than the sensors.
3. A UGV as claimed in claim 1 or claim 2, wherein the navigation is automated thereby improving inspection accuracy and repeatability.
4. A UGV as claimed in any one or more of the preceding claims, wherein the navigation system uses the infrastructure as a navigation reference.
5. A UGV as claimed in any one or more of the preceding claims, wherein the sensors include a laser scanner for sensing the position of the UGV relative to the infrastructure.
6. A UGV as claimed in claim 5, wherein the scanner is able to scan through 360°.
7. A UGV as claimed in any one or more of the preceding claims, including a distance sensor for sensing the travel distance of the UGV.
8. A UGV as claimed in claim 7, wherein the distance sensor includes a laser range finder.
9. A UGV as claimed in any one or more of the preceding claims, wherein the inspection system includes a camera configured to capture images of an interior wall of the infrastructure.

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10. A UGV as claimed in claim 9, wherein the inspection system includes a gimbal to which the camera can be mounted.
11. A UGV as claimed in claim 9 or claim 10, wherein the camera is able to rotate, preferably through 360°.
12. A UGV as claimed in any one of claims 9 to 11, wherein the camera is configured to capture images at predefined angles.
13. A UGV as claimed in any one of claims 9 to 12, wherein the inspection system includes a height adjustment mechanism for adjusting the height of the camera.
14. A UGV as claimed in any one or more of the preceding claims, further including a lighting system for lighting an interior wall of the infrastructure.
15. A UGV as claimed in any one or more of the preceding claims, wherein the navigation system includes a controller for controlling motion of the UGV whereby the UGV performs an inspection of the infrastructure at one location, prior to moving to a subsequent location for inspection.
16. A UGV as claimed in any one or more of the preceding claims, wherein UGV motion is unconstrained, and not constrained to a track, wire or other defined path.
17. An infrastructure inspection system, the inspection system including: a UGV as claimed in any one or more of the preceding claims; and a control system for controlling the UGV.
18. An infrastructure inspection system as claimed in claim 17, including a reference device fixed relative to the infrastructure to facilitate navigation.
19. A method for inspecting infrastructure with a unmanned ground vehicle (UGV), the method including the steps of:

sensing the infrastructure;

navigating the UGV relative to the sensed infrastructure; and inspecting the infrastructure.

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20. A method as claimed in claim 19, wherein the step of sensing involves sensing the position of the UGV within the infrastructure.
21. A method as claimed in claim 19 or claim 20, wherein the step of navigating involves navigating the UGV along the centre of the infrastructure.
22. A method as claimed in any one of claims 19 to 21, wherein the step of inspecting involves capturing images of an interior wall of the infrastructure.
23. A method as claimed in claim 22, wherein the location of the UGV is associated with each captured image to facilitate inspection comparisons over time by comparing images at the same location.
24. A method as claimed in claim 22 or claim 23, involving piecing the images together.