TO POSITION DETECTION AND NAVIGATION APPARATUS FOR A GUIDED ROBOTIC MACHINE OR VEHICLE

Abstract

The invention relates to the provision of a robotic machine apparatus, a movement navigation system for said robotic machine and a method of providing guidance for said robotic machine within an environment, and most typically, a confined and potentially hazardous environment. The movement navigation is provided to be operate within the environment and provide guidance remotely from personnel who are located outside of said environment. The apparatus includes means to emit at least one signal through a window of said machine and means to receive a reflected return signal from an object in or a surface of the said environment through said or another window so as to provide data to determine the location of the robotic machine and guide the movement of the machine within the environment.

Claims

1. A robotic machine apparatus for movement within an environment, said robotic machine including a movement navigation system including at least one signal transmitting means to emit a signal from internally of the apparatus and through a window to the said environment, at least one receiving means located internally of the apparatus to receive a return signal which has passed through said window or another window from an object in and/or a surface of said environment, and signal processing means to allow the said received signal to be processed and used to determine the position of the robotic machine with respect to said object and/or surface of said environment and so allow the guidance of the movement of said apparatus and wherein, at least one corrective lens is positioned intermediate the said at least one transmitting means and said window and/or intermediate said window and said receiving means.

2. The apparatus according to claim 1 wherein said at least one corrective lens is provided in addition to further optical lens provided between the said transmission means and window and between the said receiving means and window.

3. The apparatus according to claim 2 wherein the said at least one corrective lens is located intermediate the said further optical lens and the window and/or another window.

4. The apparatus according to claim 1 wherein the said at least one corrective lens is provided to correct or at least reduce distortion of the transmitted and/or the received signal caused by the same passing through the said at least one window.

5. The apparatus according to claim 1 wherein the said at least one corrective lens is a cylindrical lens.

6. The apparatus according to claim 5 wherein the said at least one corrective lens is a plano-convex cylindrical correction lens.

7. The apparatus according to claim 1 wherein a said corrective lens is provided and located between the window and said optical lens for the signal transmission means and a corrective lens is provided and located between said window and the optical lens for said signal receiving means.

8. The apparatus according to claim 1 wherein a said corrective lens is positioned so that the same lens is positioned intermediate the optical lens for the signal transmission means and the window and the optical lens for the signal receiving means and the window.

9. The apparatus according to claim 1 wherein the said transmitted signal is a laser beam.

10. The apparatus according to claim 1 wherein the said window has internal and external surfaces and at least one of which is curved.

11. The apparatus according to claim 1 wherein the said at least one window is formed with at least first and second layers.

12. The apparatus according to claim 11 wherein a first layer is provided as an infrared bandpass filter and a second layer is provided as a protective layer.

13. The apparatus according to 12 wherein the first layer forms an internal surface of the window and the second layer forms an external surface of the window.

14. The apparatus according to claim 13 wherein the first and second layers are separated by an air gap.

15. The apparatus according to claim 1 wherein a head is located internally of the said apparatus.

16. The apparatus according to claim 15 wherein any or any combination of the transmitting means, receiving means and optical lens are located on the said head.

17. The apparatus according to claim 15 wherein the said at least one window is cylindrical with a longitudinal axis which is coplanar with a centre axis of said head.

18. The apparatus according to claim 17 wherein at least the said transmitting means and receiving means are rotatable about said centre axis.

19. The apparatus according to claim 18 wherein the said head and optical lens also rotate about said centre axis.

20. The apparatus according to claim 15 wherein the said head is, or is provided within a protective housing for said movement navigation system.

21. The apparatus according to claim 15 wherein the said head is provided with a counterweight located at the opposing side of the head from that on which the said at least one optical lens is located.

22. The apparatus according to claim 21 wherein the weight of the counterweight is selected to counter the weight of the at least one optical lens and allow substantially uniform rotation of the head when in use.

23. The apparatus according to claim 1 wherein the movement navigation system is connected to control drive means connected to a plurality of wheels or rollers to enable the guided travel of the apparatus across a surface of the said environment and allow the control and guidance of the movement to be performed remotely from the location of said apparatus.

24. The apparatus according to claim 1 wherein the movement navigation system is an autonomous movement navigation system.

25. The apparatus according to claim 24 wherein the autonomous movement navigation system is a Light Detection and Ranging (LiDAR) navigation system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Specific embodiments are now described with reference to the accompanying drawings; wherein

[0025] FIG. 1 illustrates a form of the guidance head to which the invention relates in a conventional form;

[0026] FIG. 2 illustrates the head of FIG. 1 in a housing of a robotic machine of a type to which the invention relates;

[0027] FIGS. 3a and 3b illustrate in a schematic manner conventional apparatus and the inaccuracy which is caused when the same is used with a robotic machine of the type to which the invention relates;

[0028] FIGS. 4a and 4b illustrates in a schematic form the arrangement of the head in accordance with two embodiments of the invention;

[0029] FIG. 5 illustrates a head adapted for use in accordance with one embodiment of the invention; and

[0030] FIG. 6 illustrates a robotic machine of a type with which the invention can be utilized.

[0031] As such, an overview of the features, functions and/or configurations of the components depicted in the various figures will now be presented. It should be appreciated that not all of the features of the components of the figures are necessarily described and some of these non-discussed features (as well as discussed features) are inherent from the figures themselves. Other non-discussed features may be inherent in component geometry and/or configuration. Furthermore, wherever feasible and convenient, like reference numerals are used in the figures and the description to refer to the same or like parts or steps. The figures are in a simplified form and not to precise scale.

DETAILED DESCRIPTION

[0032] For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of this disclosure is thereby intended.

[0033] FIG. 1 illustrates a movement navigation system of the type which is improved in accordance with the invention. The system illustrated is of the type known as LiDAR and shows a partially disassembled head 2, in which there is provided a laser beam signal transmission means 4, and a receiving means in the form of a detector 6 for receiving a reflected return signal (illustrated and discussed later). A first optical lens 8 is provided through which the laser beam signal is transmitted to the external environment and a second optical lens 10 is provided through which the reflected signal passes from the external environment to the receiver 6. The transmitted and received signals pass through one or more windows 14.

[0034] The robotic machines 12 to which the current invention is particularly related are provided for use in environments to perform inspection of apparatus and equipment located within the environment which may contain flammable liquids and gasses such that the robotic machines are required to be explosion safe and have ATEX, the name commonly given to the two European Directives for controlling explosive atmospheres which are Directive 99/92/EC and Directive 2014/34/EU and/or similar certification. One form of robotic machine 12 is illustrated in FIG. 6. The head 2 for the guidance system is typically located within a 9.5 mm thick cylindrical borosilicate protection window 14, in a housing 15 shown in FIG. 6 and part of which is shown in FIG. 2, which illustrates the top surface 16 of the robotic machine and shows how the head 2 and surrounding window 14 and housing 15 project upwardly in a turret like fashion from the top surface 16. Also located within the body 21 of the robotic machine is control circuitry, movement means 19 such as wheels or tracks and a drive means such as one or more motors to allow steering and driven movement of the robotic machine to move around the environment surface 17 in a controlled manner. The body may also contain one part of a power cell charging assembly to charge the power cells located within the body and an example of this type of apparatus is disclosed in the applicant's patent NL2019636, the contents of which are incorporated herein by reference.

[0035] Thus, the aim is to allow the robotic machine or vehicle, once placed within the environment, to be autonomously operable within the environment and, furthermore, to be operable for a significant period of time during which the power cells may be charged multiple times and therefore avoid, as much as possible, exposure of personnel to the environment in which the vehicle is used. Whilst in the environment, the vehicle can be used to perform routine and/or emergency maintenance and other tasks using a selective range of facilities which may be provided on the body and the particular range of facilities provided on the body may be selected with regard to the specific environment, such as oil and/or gas supply environments in which the same is to be operated. Thus, robotic machines or vehicles of this type can be of significant advantage.

[0036] It is therefore imperative, for the successful operation of the automated detection means, that accurate feedback of the location is always provided.

[0037] It is found that in practice, the provision of the protective window 14 causes a variation in the transmitted and/or received signals of the guidance apparatus which can cause the distortion discussed above to be created and this is illustrated in FIGS. 3a and b which show a plan view of the head 2 and window 14. In FIG. 3a it is shown how in the conventional apparatus the thick walls of the circular window 14 effectively act as a negative lens and causes displacement of the transmitted laser beam 18 and the detector field of view 20 as the window is causing them to change to point to a different angular direction when passing through the window, It is found that the deviation of both beams can be, for example, 0.6 degrees with respect to respective central axes 22, 24, leading to a total angular separation of 1.2 degrees between laser signal 18 and detector field of view 20.

[0038] As a result of this deviation, the detector 6 is unlikely to always be able to detect the reflection 26 of the laser beam 18 and an example of this is shown in FIG. 3b, as the reflection 26 falls outwith the field of view 20 due to the misalignment in position of the reflected signal. This is a problem for both longer and shorter detection distances as the deviation of 1.2 degrees is much larger than the angular resolution of the movement navigation system which is typically ?0.2 degree.

[0039] In accordance with the invention as now claimed, this problem is solved by the provision of at least one but preferably two corrective lenses to the detector head 2 to compensate for the effect of the window 14.

[0040] In FIG. 4a this is achieved by the provision of a corrective lens which in this embodiment, is in the form of a confocal lens 30 which is added to the head and is located intermediate the existing lens 8,10 and the window 14 as illustrated. It should be noted that the window may act as, or include an IR band pass filter window 36 as illustrated in FIG. 4b or alternatively can be a protective window adapted for use with the apparatus for use with robotic machines and which may be formed of a hard wearing and preferably blast resistive material such as borosilicate or another material or materials.

[0041] In FIG. 4b another solution is shown and this includes the provision of corrective lens 32, 34, with lens 32 provided intermediate the optical lens 8 for the laser beam 18 so that the beam now passes through the lens 8 and lens 32 before passing through the optionally provided IR band pass filter window 36 and the protective window 14 and the corrective lens 34 is located such that the reflected laser beam signal 26 passes through the window 14, the optionally provided IR band pass filter window 36, the corrective lens 34 and then lens 10 before reaching the detector 6.

[0042] It is shown that in both of these embodiments the reflected beam signal 26 is now within the area of vision of the detector 6 and so accurate determination of the received reflected signal 26 can be processed and accurate guidance provided to the movement of the robotic machine using the conventional guidance methodology of the LiDAR or another guidance system.

[0043] These arrangements are illustrated on a head 2 of the type shown in FIG. 1 but adapted in accordance with the schematic arrangement shown in FIG. 4b. A counter weight 38 is provided on the opposing side of the head 2 from the lens 32,34 so as to balance the weight of the head and allow smoother and balanced rotation of the same about centre axis 40.

[0044] Tests were undertaken to determine the measurement of the maximum intensity and maximum detection distance and this was performed in the following 3 configurations: [0045] 1. LiDAR with IR band pass filter window 36, without corrective lenses (+IR, no lenses); [0046] 2. LiDAR with IR band pass filter window 36, with lenses 32, 34 attached (+IR, with lenses); [0047] 3. LiDAR without IR band pass filter window, with lenses 32,34 attached (?IR, with lenses)

[0048] In all 3 above configurations, measurements were done without the borosilicate window 14 and with the borosilicate window 14.

Maximum Intensity and Distance Measurements

[0049] The results are summarized in table 1 (outside environment) and table 2 (inside environment). The values in the table are indicative averages and can vary typically by around 15%.

TABLE-US-00001 TABLE 1 Maximum signal strength and distance measured with outside environment (from window) Maximum signal Maximum strength distance No With No With window window window window Config1 (+IR, no lenses) 130 30 80 20 Config2 (+IR, with lenses) 125 125 60 60 Config3 (?IR, with lenses) 70 150 33 80-100

[0050] Table 1 clearly shows that the corrective optics lens 32, 34 have the best results without the IR filter 36 present. However, the lens correction does also give a significant improvement with the IR filter 36 in place. With corrective optics present, the performance of the LiDAR without the borosilicate window present drops off, because the corrective effect of the lenses works against this configuration.

TABLE-US-00002 TABLE 2 Maximum and average signal strength measured in inside environment (room) Maximum signal Average signal strength strength No With No With window window window window Config1 (+IR, no lenses) 130 30 80 20 Config3 (?IR, with lenses) 140 140 40 100

[0051] In Table 2, it is shown that that the average signal increases also significantly by the corrective lenses 32, 34 when the borosilicate window 14 is present in this distance range.

[0052] Thus, the use of cylindrical correction lenses 32, 34 improves the guidance system sensitivity significantly when used in combination with thick cylindrical glass windows. If the correction lenses are separated over several mm, then it will be better to use a lens with a shorter focal length and also for a system that uses a combination of an IR-filter window 36 and a Borosilicate window 14. It should also be noted that although reference is made to the window 14 being made of Boroslicate, other materials or combinations of material may be used to provide the same or a similar effect. Furthermore, although the reference is made to the use of the invention with the LiDAR navigation system, the invention may be used to provide the same or similar advantages when utilised with autonomous navigation systems other than LiDAR.

[0053] The invention therefore provides a robotic machine apparatus, a movement navigation system for said robotic machine and a method of providing guidance for said robotic machine within an environment, and most typically, a confined and potentially hazardous environment. The movement navigation is provided to be operate within the environment and provide guidance remotely from personnel who are located outside of said environment. The apparatus includes means to emit at least one signal through a window of said machine and means to receive a reflected return signal from an object in or a surface of the said environment through said or another window so as to provide data to determine the location of the robotic machine and guide the movement of the machine within the environment. At least one optical lens is provided intermediate the signal transmitting means and window and/or signal receiving means and said window, or another window, in order to allow any distortion caused by the signals passing through said at least one window to be reduced or avoided and thereby allow more accurate guidance of the apparatus.

[0054] While various embodiments of devices and systems and methods for using the same have been described in considerable detail herein, the embodiments are merely offered as non-limiting examples of the disclosure described herein. It will therefore be understood that various changes and modifications may be made, and equivalents may be substituted for elements thereof, without departing from the scope of the present disclosure. The present disclosure is not intended to be exhaustive or limiting with respect to the content thereof. Further, in describing representative embodiments, the present disclosure may have presented a method and/or a process as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth therein, the method or process should not be limited to the particular sequence of steps described, as other sequences of steps may be possible. Therefore, the particular order of the steps disclosed herein should not be construed as limitations of the present disclosure. In addition, disclosure directed to a method and/or process should not be limited to the performance of their steps in the order written. Such sequences may be varied and still remain within the scope of the present disclosure.