WO2018087429A1

WO2018087429A1 - Angle detection of elongated object of vessel by lidar

Info

Publication number: WO2018087429A1
Application number: PCT/FI2017/050770
Authority: WO
Inventors: Oskar Levander
Original assignee: Rolls-Royce Oy Ab
Priority date: 2016-11-09
Filing date: 2017-11-08
Publication date: 2018-05-17
Also published as: FI127026B; FI20165844A

Abstract

The object is to provide angle (12',12'') detection of an elongated object (15) of a vessel (10) by a LIDAR (11). In an embodiment, an apparatus (30) is dis- closed. The apparatus comprises: a LIDAR (11); a pro- cessor (36); a storage (37) comprising a set of in- structions (38,40) that, when executed by the proces- sor, cause the apparatus to: receive, from the LIDAR, sensor signals (14') indicative of an elongated object (15) extending from a vessel (10) comprising the appa- ratus; determine a line based on the sensor signals indicative of the elongated object; receive data in- dicative of a reference line (16) with respect to the vessel; and determine an angle (12',12'') between the line indicating the elongated object and the reference line, wherein the angle represents the angle of the elongated object with respect to the vessel.

Description

ANGLE DETECTION OF ELONGATED OBJECT OF VESSEL BY LIDAR BACKGROUND

A vessel, such as a ship, may detect its en- vironment and surroundings by various detectors which may be alternatively referred to as sensors. The de^¬ tectors provide information to a control system of the vessel, which may be used to render data information about the current situation of the vessel or an object nearby the vessel. This data information may be out^¬ put, for example for control, navigation or monitoring purposes of the vessel.

SUMMARY

This summary is provided to introduce a se^¬ lection of concepts in a simplified form that are fur^¬ ther described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

It is an object to provide angle detection of an elongated object of a vessel by LIDAR. The object is achieved by the features of the independent claims. Further embodiments are described in the dependent claims. In an embodiment, an apparatus is disclosed. The apparatus comprises: a LIDAR; a processor; a stor^¬ age comprising a set of instructions that, when exe^¬ cuted by the processor, cause the apparatus to: re- ceive, from the LIDAR, sensor signals indicative of an elongated object extending from a vessel comprising the apparatus; determine a line based on the sensor signals indicative of the elongated object; receive data indicative of a reference line with respect to the vessel; and determine an angle between the line indicating the elongated object and the reference line, wherein the angle represents the angle of the elongated object with respect to the vessel.

In other embodiments, a vessel including the ap^¬ paratus, a method and a computer program are discussed along with the features of the apparatus.

Many of the attendant features will be more readily appreciated as they become better understood by reference to the following detailed description considered in connection with the accompanying drawings .

BRIEF DESCRIPTION OF THE DRAWINGS

The present description will be better understood from the following detailed description read in light of the accompanying drawings, wherein:

FIG. 1 illustrates a schematic top view of a ves sel connected to an assisted ship by an elongated object extending from the vessel, illustrating a horizontal angle of the object according embodiment ;

FIG. 2 illustrates a schematic side view of a vessel connected to an assisted ship by an elon gated object extending from the vessel, illus trating a vertical angle of the object according to an embodiment;

FIG. 3 illustrates a schematic side view of a vessel having an elongated object extending from the vessel, which is monitored by a LIDAR accord ing to an embodiment; FIG. 4 illustrates a schematic top view of a ves^¬ sel having an elongated object, which is moni^¬ tored by a LIDAR according to an embodiment; and FIG. 5 illustrates a block diagram of a computer for a LIDAR system of a vessel according to an illustrative embodiment.

Like reference numerals are used to designate like parts in the accompanying drawings. DETAILED DESCRIPTION

The detailed description provided below in connection with the appended drawings is intended as a description of the present embodiments and is not in^¬ tended to represent the only forms in which the pre- sent embodiments may be constructed or utilized. How^¬ ever, the same or equivalent functions and sequences may be accomplished by different embodiments.

Although the present embodiments may be de^¬ scribed and illustrated herein as being implemented in a tug or a towing ship, this is only an embodiment of a vessel having a computer and not a limitation. As those skilled in the art will appreciate, the present embodiments are suitable for application in a variety of different types of systems and in vessels, for ex- ample in a single ship, many ships, a maritime system, a decision support tool for a user or crew, a marine remote control system, an autonomous marine navigation or position system, or other marine systems for detecting or determining an angle between an elongated object extending from the vessel.

An embodiment relates to using a LIDAR to measure an angle of an elongated object extending from a vessel, such as a rope, for example a towing rope. A detector of the angle provides this information for a vessel control system, for example a dynamic position- ing (DP) system and the operator. According to an embodiment, a LIDAR can measure both horizontal and ver^¬ tical angles of the elongated object.

An embodiment relates to tug boat operation. The rope angle together with the rope force, which may be measured in the winch, gives valuable input for the tug operator or for the control system, such as DP control system, of the tug. According to an embodi^¬ ment, the rope angle may also be a safety parameter. The towing system can be set with some predetermined values for a heeling moment, based on a combination of force and rope angle, at which the winch should re^¬ lease the tension on the rope to avoid dangerous situ^¬ ations .

According to an embodiment, the apparatus may also be used for anchor handling operations (such as anchor handling tug supply, AHTS), offshore support vessel (OSV) pipe loading operations, etc. The elon^¬ gated object extending from the vessel may be an an- chor rope or a pipeline to be installed or inspected.

An embodiment utilizes a LIDAR, also written LADAR, as a surveying technology that measures dis^¬ tance by illuminating a target with a laser or a noncoherent light. Lidar is an acronym of Light Detection And Ranging. A lidar may use ultraviolet, visible, or near infrared light to image objects. It can target a wide range of materials, including non-metallic ob^¬ jects, rocks, rain, chemical compounds, aerosols, clouds, water, or even single molecules. A narrow la- ser-beam can map physical features with very high res^¬ olutions .

The portion of the lidar data, which is re^¬ lated to the rope, is selected. Other reflections from other objects may be discarded. According to an embod- iment only those points, which reside outside the ship, are selected so that various objects belonging to the ship will not disturb the rope angle determina- tion. Also the reflections from the assisted ship may be discarded. According to an embodiment, a minimum and maximum distance may be set to guarantee selecting reflections form the rope only. In addition, points related to the water surface can be discarded based on their elevation. Naturally, other kinds of selection methods are also possible. Such methods may be needed, if the system needs to discard points related another rope used by another tug, for example. According to an embodiment, certain filtering of the data may also be used to discard flying seagulls, for instance. Time domain filtering of the calculated angles may be ap^¬ plied and be efficient. A median filter may be also used .

FIG. 1 illustrates a schematic top view of a vessel 10 connected to an assisted ship 13 by an elon^¬ gated object 15 extending out from the vessel 10, il^¬ lustrating a horizontal angle 12' of the object 15 ac^¬ cording to an embodiment. In the embodiment of FIG. 1, the vessel 10 comprises a tug and the elongated object 15 extending from the vessel 10 comprises a rope, such as a towing rope.

The tug 11 tows the assisted ship 13 by the rope 15. When towing, the rope moves to different an- gles depending on the positions of the tug 11 and the assisted ship 13. The tug 11 comprises a LIDAR 11 and a winch 17. The winch 17 winds the rope 15, and at^¬ taches it to the tug 10. The LIDAR 11 emits signals 14, the reflections of which the LIDAR 11 is able to detect. The signals 14' illustrate signals colliding with the rope 15 at different points, having different distances from the LIDAR 11. The LIDAR 11 detects these reflections. A computer 30 may be included in the LIDAR 11 or be connected to the LIDAR 11. Accord- ing to an embodiment, the computer 30 may be a part of a control system of the vessel 10. The computer 30 re^¬ ceives signals 14' indicative of the rope 15. The com- puter 30 creates a model representing the rope 15. This may be a substantially straight line. For exam^¬ ple, the LIDAR 11 gives a set of points, illustrating the detections of the LIDAR 11 for the rope 15, to the computer 30. The computer may be configured, by the programmable code or logic, to use a regression analy^¬ sis to derive the coefficients of the equation of the best matching straight line representing the rope 15.

The computer 30 receives a reference line 16. According to an embodiment of FIG. 1, this may be heading 16 of the tug 10. The heading 16 may be re^¬ ceived from the control system of the vessel 10. The computer 30 determines an angle 12' between the reference line 16 and the elongated object 15, for example between the heading 16 and the rope 15. The angle 12' may be a horizontal angle in the xy plane.

The angle 12' may be utilized for controlling the vessel 10, steering the vessel 10, and/or it may act as a safety parameter etc.

According to an embodiment, the vessel 10 comprises a winch 17 winding the elongated object 15 which is flexible, such as a rope 15 or a flexible pipeline. The computer 30 receives data indicative of a force relating to the elongated object with respect to the winch 17. It combines the data indicative of the force with the angle 12. It may further compare the combined data to a certain reference value, for example an allowed maximum force, which may be even combined together with the angle information. It out- puts an alert signal when the combined data exceeds the reference value. For example, when the tug 10 fur^¬ ther includes the winch 17 which is configured to store the towing rope 15, the control system of the vessel 10 may be configured to release the winch 17 controlling the towing rope 15 on the basis of the alert signal. FIG. 2 illustrates a schematic side view of a vessel 10 connected to an assisted ship 13 by an elon^¬ gated object 15 extending from the vessel 10, illus^¬ trating a vertical angle 12'' of the object 15 accord- ing to an embodiment. The embodiment of FIG. 2 is sim^¬ ilar to the embodiment of FIG. 1, except that the com^¬ puter 30 determines the vertical angle 12'' instead of the horizontal angle 12'. A water surface 16 is acting as the reference line 16 in the embodiment of FIG. 2. The LIDAR 11 may determine the water surface based on signals 14 reflecting from the water surface. The angle 12'' may be a vertical angle in the z plane.

According to an embodiment, the computer 30 may combine both of the horizontal angle 12' and the vertical angle 12''. This may establish a three dimen^¬ sional model of the elongated object 15, such as the rope, between the vessel 10 and the assisted ship 13. It should be noted that this may also be the other way round, for example the computer 30 determines the three dimensional (3D) angle between the rope 15 and the reference line using the data received from the LIDAR 11. Now horizontal and vertical angles 12', 12'' are derived from the 3D angle by the computer 30.

FIG. 3 illustrates a schematic side view of a vessel 10 having an elongated object 15 extending from the vessel 10, wherein the object 15 is monitored by a LIDAR 11 according to an embodiment. The embodiment of FIG. 3 detects the elongated object 15 even without another vessel. The LIDAR 11 of the vessel 10 may mon- itor the elongated object 15 and establish a vertical angle 12'' with respect to the reference line 16. In the embodiment of FIG. 3, the elongated object 15 may, for example, be an anchor rope or wire. This may be used at the AHTS of the vessel 10. An embodiment re- lates to OSV pipe loading operations etc., wherein the elongated object 15 extending from the vessel 10 may be a pipeline to be installed, inspected, repaired, etc .

FIG. 4 illustrates a schematic top view of a vessel 10 having an elongated object 15 extending from the vessel 10, which is monitored by a LIDAR according to an embodiment. The embodiment of FIG. 4 is similar to FIG. 3, except that a horizontal angle 12' is de^¬ tected instead of the vertical angle 12'. The heading 16 of the vessel 10 is acting as the reference line 16 for the horizontal angle 12' in the x and y plane.

FIG. 5 illustrates an embodiment of compo^¬ nents of a computer 30 which may be implemented in any form of a computing and/or electronic device configured for performing the functionalities and operations of the embodiments of FIG. 1 to 4 relating to the com^¬ puter 30 operating with the LIDAR 11 in the vessel 10. The computer 30 comprises output 41, input 3, in^¬ put/output controller 39, user interface 31, processor 36, storage 37, operating system 38, application soft- ware 40. The computer 30 is equipped with the proces^¬ sor 36 and storage 37 comprising a set of instructions 38, 40. The one or more processors 36 may be micropro^¬ cessors, controllers or any other suitable type of processors for processing computer executable instruc- tions to control the operation of the computer 30. The set of instructions 38 may comprise, for example, application software 40 and platform software, such as an operating system to enable application software to be executed on the computer 30. When the set of in- structions 38,40 is executed by the processor 36, the computer 30 is configured to perform the functions and operations described above in the embodiments of FIG. 1 to 4. According to an embodiment, the computer 30 is configured to receive, from the LIDAR 11, sensor sig- nals 14' indicative of an elongated object 15 extend^¬ ing from a vessel 10 comprising the apparatus; determine a line based on the sensor signals 14' indicative of the elongated object 15; receive data indicative of a reference line 16 with respect to the vessel 10; de^¬ termine an angle 12', 12'' between the line indicating the elongated object 15 and the reference line 16. The angle 12', 12'' represents the angle of the elongated object 15 with respect to the vessel 10.

Alternatively, or in addition, the functionality described herein can be performed, at least in part, by one or more hardware logic components.

The term 'computer', 'computing-based de^¬ vice', 'apparatus' or 'device' is used herein to refer to any device with processing capability such that it can execute instructions. Those skilled in the art will realize that such processing capabilities are in- corporated into many different devices and therefore the terms 'computer' and 'computing-based device' each include different types of computer devices, for exam^¬ ple, servers, cloud computers, or any other computing devices that are enabled for the SA system.

Although the subject matter has been de^¬ scribed in language specific to structural features and/or acts, it is to be understood that the subject matter defined in the appended claims is not neces^¬ sarily limited to the specific features or acts de- scribed above. Rather, the specific features and acts described above are disclosed as embodiments of imple^¬ menting the claims and other equivalent features and acts are intended to be within the scope of the claims .

It will be understood that the benefits and advantages described above may relate to one embodi^¬ ment or may relate to several embodiments. The embod^¬ iments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will fur^¬ ther be understood that reference to 'an' item refers to one or more of those items.

The steps of the method described herein may be carried out in any suitable order, or simultaneous^¬ ly where appropriate. Additionally, individual blocks may be deleted from any of the methods without depart^¬ ing from the spirit and scope of the subject matter described herein. Aspects of any of the embodiments described above may be combined with aspects of any of the other embodiments described to form further embod^¬ iments without losing the effect sought.

The term 'comprising' is used herein to mean including the method, blocks or elements identified, but that such blocks or elements do not comprise an exclusive list and a method or apparatus may contain additional blocks or elements.

It will be understood that the above descrip- tion is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of exem^¬ plary embodiments. Although various embodiments have been described above with a certain degree of particu^¬ larity, or with reference to one or more individual embodiments, those skilled in the art could make nu^¬ merous alterations to the disclosed embodiments with^¬ out departing from the spirit or scope of this speci- fication.

Claims

1. An apparatus (30), comprising:

a LIDAR (11) ;

a processor (36);

a storage (37) comprising a set of instructions (38,40) that, when executed by the processor, cause the apparatus to:

receive, from the LIDAR, sensor signals (14') indicative of an elongated object (15) extending from a vessel (10) comprising the apparatus; characterized by

determine a line based on the sensor signals indicative of the elongated object;

receive data indicative of a reference line (16) with respect to the vessel;

determine an angle (12', 12'') between the line indicating the elongated object and the reference line, wherein the angle represents the angle of the elongated object with respect to the vessel; and

output the angle to a control system of the vessel, wherein the control system is configured to perform an action controlling the vessel based on the angle .

2. The apparatus of any preceding claim, wherein the reference line comprises a heading of the vessel.

3. The apparatus of claim 1, wherein the angle com^¬ prises a horizontal angle (12') in x- and y-plane.

4. The apparatus of any preceding claim, wherein the reference line comprises water surface of the vessel.

5. The apparatus of claim 4, wherein the angle com- prises a vertical angle (12'') in z-plane.

6. The apparatus of any preceding claim, wherein the elongated object extending from the vessel comprises a towing rope, an anchor rope, or a pipeline.

7. The apparatus of any preceding claim, wherein the elongated object extending from the vessel comprises a towing rope and the vessel comprises a tug, wherein the towing rope is configured between the tug and an assisted ship of the tug.

8. The apparatus of any preceding claim, wherein the set of instructions, when executed by the processor, further causes the apparatus to:

receive data indicative of a force relating to the elongated object; and

combine the data indicative of the force with the angle.

9. The apparatus of claim 8, wherein the set of in- structions, when executed by the processor, further causes the apparatus to:

compare the combined data to a reference val^¬ ue ; and

output an alert signal when the combined data exceeds the reference value.

10. The apparatus of any preceding claim, wherein the tug further includes a winch (17) which is configured to store the towing rope, and wherein a control system of the vessel is configured to release the winch con^¬ trolling the towing rope on a basis of the alert sig^¬ nal .

11. A vessel comprising the apparatus of any preceding claims.

12. The vessel of claim 11, wherein the vessel comprises a ship.

13. A method, comprising:

receiving, from a LIDAR (11), sensor signals

(14') indicative of an elongated object

(15) extending from a vessel (10) comprising the apparatus;

determining a line based on the sensor signals indicative of the elongated object;

receiving data indicative of a reference line

(16) with respect to the vessel;

determining an angle (12', 12'') between the line indicating the elongated object and the reference line, wherein the angle represents the angle of the elongated object with respect to the vessel; and

outputting the angle to a control system of the vessel, wherein the control system is configured to perform an action controlling the vessel based on the angle.

14. A computer program, comprising a set of instructions which are configured to cause a computer to per^¬ form the steps of claim 13 when executed.