Method and an unmanned aerial vehicle for determining emissions of a vessel

Abstract

A method for determining emissions in an exhaust plume (11) produced by a combustion engine of a vessel (10) during cruise of the vessel (10), said emissions including the presence or concentration of carbon dioxide (CO.sub.2) and/or sulphur dioxide (SO.sub.2) and/or the count and size of particles. The position and distribution of the exhaust plume (11) is determined or estimated on the basis of the position, bearing and speed of the vessel (10) and further on the basis of meteorological data, such as wind direction and speed. An unmanned aerial vehicle (UAV) (12), i.e. a so-called drone, is controlled to fly through the 10 plume (11) to make measurements of exhaust emissions of the vessel (10).

Claims

1. A method for determining emissions in an exhaust plume produced by a combustion engine of a vessel during cruise of the vessel, said emissions comprising the presence or concentration of at least one predetermined gas or the count and size of particles, the method comprising the steps of: identifying the vessel, its position, bearing and speed; determining meteorological conditions in an area cruised by the vessel; providing an unmanned aerial vehicle (UAV) comprising: an electronic control system for controlling the vehicle's flight; at least one sensor for determining emissions in the atmosphere surrounding the vehicle; a data interface of passing signals to an external data collecting unit, said signals comprising at least one of: (a) an output signal of the at least one sensor and (b) data obtained from the output signal of the at least one sensor; determining a position and distribution of the exhaust plume on the basis of the position, bearing and speed of the vessel and further on the basis of said meteorological conditions; controlling the UAV to: fly through the exhaust plume; determine said emissions in the exhaust plume by means of the at least one in situ sensor for non-optically analyzing gas, air, or the combination thereof; and transmit said signals to an external data collecting unit for further processing thereof, wherein the step of controlling the UAV comprises determining or adjusting a flight mission, including at least a flight trajectory for the UAV during flight, and wherein the step of determining or adjusting the flight trajectory is carried out on the basis of meteorological conditions, vessel position, bearing and speed, and sensor data provided by output signals of the at least one sensor in order to navigate the UAV towards a region a highest determinable gas concentration or particle count within the exhaust plume.

2. The method according to claim 1, wherein the meteorological conditions at least include a current, forecasted, or current and forecasted wind speed and wind direction in the area cruised by the vessel.

3. The method according to claim 1, wherein the step of determining said emissions in the exhaust plume comprises the step of sampling sets of data, each set of data comprising sensor data obtained by the at least one sensor, a time of the sample, and a position of the vessel(s) or the UAV at the time of the sample, or the position of the vessel(s) and the UAV at the time of the sample.

4. The method according to claim 1, wherein the UAV comprises an electronic processor for analyzing the sensor data.

5. The method according to claim 1, wherein the emissions determined by the at least one sensor comprise at least carbon dioxide, sulphur dioxide, fine or ultrafine particles, or combinations thereof.

6. The method according to claim 1, wherein the step of controlling the UAV comprises determining a flight mission comprising at least a flight trajectory for the UAV prior to take off, the flight mission optionally including or optionally excluding flight velocities of the UAV.

7. The method according to claim 1, wherein the step of controlling the flight trajectory for the UAV comprises, at least during a part of its flight through the UAV, flying the UAV at a speed and direction which is approximately equal to the vector sum of the speed and direction of the vessel and a current average speed and direction of wind at the vessel's position.

8. The method according to claim 1, wherein the step of controlling the flight trajectory for the UAV comprises, at least during a part of its flight through the UAV, flying the UAV at an approximately constant distance from the vessel, preferably at the center line of the plume.

9. The method according to claim 1, wherein the step of determining or adjusting the flight trajectory is carried out by the control system of the UAV.

10. The method according to claim 9, comprising said step of adjusting the flight trajectory on the basis of at least output signals of the at least one sensor, and wherein adjusting the flight trajectory comprises repeatedly determining a rate of change of a concentration of the emissions, and optionally further the position, course and speed of the vessel(s), and meteorological conditions, and wherein the flight trajectory is adjusted in case said rate of change is negative or otherwise warrants it.

11. The method according to claim 9, wherein the step of adjusting the flight trajectory comprises adjusting a bearing, heading, an altitude of the UAV, or combinations thereof.

12. The method according to claim 1, notably for the determination of sulphur emissions of the vessel, wherein the at least one sensor is arranged within a closed chamber, and wherein: the flight trajectory of the UAV is controlled or adjusted during its flight, notably on the basis of vessel speed, course, meteorological conditions, sensor data, or combinations thereof; in situ sensor measurements are carried out by the at least one sensor in said chamber; and intake of gas, air, or the combination thereof, into the sensor chamber is controlled for achieving a steady state at the intended measurement site, notably by shutting the air or gas intake at the intended measurement site.

13. An unmanned aerial vehicle (UAV) for determining emissions comprising the presence or concentration of at least one predetermined gas or the count and size of particles, the UAV comprising: an electronic control system for controlling the vehicle's flight; at least one sensor for determining emissions in the atmosphere surrounding the vehicle; a data interface of passing signals to an external data collecting unit, said signals comprising at least one of: (a) an output signal of the at least one sensor and (b) data obtained from the output signal of the at least one sensor; the UAV being controllable to: fly through an area of interest; determine said emissions in the area of interest by means of the at least one in situ sensor for non-optically analyzing gas, air, or combinations thereof; transmit said signals to an external data collecting unit for further processing thereof, wherein the electronic control system is configured to determine or adjust a flight mission, including at least a flight trajectory for the UAV during flight on the basis of meteorological conditions, vessel position, bearing and speed, and sensor data provided by output signals of the at least one sensor in order to navigate the UAV towards a region a highest determinable gas concentration or particle count within the exhaust plume.

14. The unmanned aerial vehicle according to claim 13, wherein the at least one sensor comprises a plurality of sensors arranged in a sealed sensor chamber housed within a fuselage of the UAV, into which air is passed, by sucking by a pump through an air intake provided on an outer surface as well as inside the fuselage of the UAV.

15. The unmanned aerial vehicle according to claim 14 wherein air suction into the sensor chamber is controllable to reach steady state by way of turning on or off the air pump once at least one predetermined concentration threshold is reached.

16. The unmanned aerial vehicle according to claim 13, wherein the at least one sensor comprises a non-optical sensor for chemically or electrochemically analyzing gas, air, or combinations thereof coming into contact with a surface of the sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention will now be further described with reference to the drawings, in which:

(2) FIG. 1a shows a vessel, its exhaust plume and the flight trajectory of a UAV in one embodiment of the invention seen from above;

(3) FIG. 1b illustrates the vessel, exhaust plume and flight trajectory of the embodiment of FIG. 1 in a side view;

(4) FIG. 2 generally depicts hardware components applicable in a preferred embodiment of the invention;

(5) FIG. 3 illustrates a first embodiment of a sensor configuration of a UAV for determining emissions;

(6) FIG. 4 illustrates a second embodiment of a sensor configuration of a UAV for determining emissions;

(7) FIG. 5 is a flow chart generally illustrating the steps of one embodiment of the method according to the first aspect of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

(8) FIG. 1a shows a top view of a vessel 10, its exhaust plume 11 and the flight trajectory 13 of a UAV 12 in one embodiment of the invention. In one embodiment (not shown), the UAV may zig-zag through the exhaust plume. As shown, the UAV 12 navigates from behind the exhaust plume 11 along the centre line of the plume 14 towards the vessel 10. At position A, the exhaust plume entry point, the gas and particle sensors of the UAV 12 determine an increased concentration of emissions, and the UAV 12 starts its flight path along the centre line of the plume 14 towards position D, the optimal sampling point. At positions B through C (or multiples hereof), the UAV 12 is adjustedor adjusts itselfto remain on course along the centre line of the plume 14 towards the vessel. Adjustments are made based on real-time changes in vessel 10 position, course and speed, meteorological conditions 15, and/or detected changes in gas or particle concentrations. Sampling is done continuously throughout the mission. Once reaching position D, the air speed of the UAV 12 is adjustedor adjusts itselfalong with adjustments in GPS position in order to maintain constant distance to the vessel 10 at the centre line of the exhaust plume 14 for optimal sampling.

(9) After reaching D, defined at the optimal sampling point, and remaining there until concentration levels reach a predetermined threshold, the UAV 12 exists the plume 11. The flight trajectory 13 is shown in a side view in FIG. 1b. As shown, the UAV 12 may fly at variable latitudes, longitudes and altitudes as well as speeds through the plume 11 in order to optime the flight path for sampling. In FIGS. 1a and 1b, the direction of wind is indicated by arrows 15, the bearing of the vessel 10 is indicated by arrows 16, and the heading of the UAV 12 is indicated by arrows 17. The UAV 12 may alternatively be controlled to fly through the plume 11 at a fixed altitude and/or along a pre-programmed flight trajectory.

(10) At position D, the flight trajectory 13 may be adjusted to fly the UAV 12 at a speed and direction which is approximately equal to the vector sum of the speed and direction of the vessel 10 and a current average speed and direction of wind at the vessel's 10 position. The UAV 12 may hence be flown within a particular mist of particles and emission of gasses for a period of time, which allows taking into account a possible response time of the sensors of the UAV and/or adjustments in the conditions governing the optimal flight trajectory. Alternatively, at position D the UAV may be flown at an approximately constant distance from the vessel 10 for a certain period of time in order to obtain a steady state condition for the sensors.

(11) FIG. 2 generally depicts hardware components applicable in a preferred embodiment of the invention. The vessel 10 may communicate signals, such as position and course signals, to a remote control facility 18, e.g. via the AIS. The remote control facility 18 in turn controls the UAV 12 based on received sensor, position and other signals transmitted from the UAV 12 or other sources. Position and course signals of the vessel 10 may also be captured by the UAV 12 and subsequently relayed to the remote control facility 18. Satellite 19 is provided for GPS control and position determination of the UAV 12 and vessel 10. Sample diagnostics may be performed both on-board the UAV during flight or by the remote control facility 18. Once analysed, the remote control facility 18 uploads all data including vessel information, mission log, sample data and diagnostics results to a cloud-based storage facility 20 accessible by various remote user devices 21.

(12) FIG. 3 illustrates a first embodiment of a sensor configuration of a UAV for determining emissions, wherein sensors, including gas sensors and/or particle counters 23, 24, 25, and 26 are mounted externally on a structure 22, which in turn attaches to a wing 27 of the UAV 12, the structure having a rounded front tip 28. As the UAV moves relative to incoming wind 15a, air vortices occur downstream of respective protective casings 29 of the sensors 23, 24, 25 and 26. In the vortices, the sensors 23, 24, 25 and 26 perform measurements, and output signals thereof are communicated through wired or wireless communication paths to a control system (not shown) of the UAV and/or directly to a remote control facility, such as control facility 30 shown in FIG. 2.

(13) FIG. 4 illustrates a second embodiment of a sensor configuration inside a UAV fuselage 22 for determining emissions, wherein sensors, including gas sensors and/or particle counters 23, 24, 25, 26 are housed within a sealed sensor chamber 27 along with the sensor control board 28. The air 29 is sucked into the sensor chamber 27 using a pump 30 fitted with an on/off relay 31. In order to minimise effects of gusts in wind 15 (not shown), the air is guided via a perforated air intake tube 32, closed off at the tip, through a filter 33, into the sensor chamber 27. Air exits the sensor chamber 27 at outlet 34.

(14) In FIGS. 3 and 4, each of the respective sensors 23, 24, 25 and 26 may serve its own purpose, i.e. be specifically designed for measuring a particular gas and/or count of particles.

(15) For example, one of the four sensors in each embodiment may be for the measurement of CO.sub.2, another one for the measurement of SO.sub.2, a third one for measurement of NO.sub.2, and a fourth one for the count of particles.

(16) FIG. 5 is a flow chart generally illustrating the steps of one embodiment of the method according to the first aspect of the invention. Initially one or more vessels are identified along with its/their position, course and speed. Current or forecasted meteorological conditions at the position of the vessel(s) are then determined. On the basis of the vessel position, course, speed and meteorological conditions, the position of the targeted centre line of the vessel's exhaust plume is subsequently estimated/forecasted. The entire flight mission or a part of the flight mission for the UAV may then be determined prior to take off of the UAV.

(17) Once launched the UAV will take up a loiter pattern above the launch point until such time when the vessel reaches the mission start position. This position is predetermined to ensure enough mission track along the centre line of the plume to perform a successful sampling.

(18) Sampling is done continuously throughout the flight mission and sampled data are stored on-board as well as relayed real-time to the remote control facility. As the UAV arrives at the entry point of the plume (A), it is controlled to fly through the exhaust plume along the targeted centre line of the plume towards the optimal sampling point (D) at the determined speed. Once reaching D, the UAV will adjust its speed and position to remain at point D until such time when the predetermined concentration threshold is reached. The threshold triggers the on-board relay to stop the pump allowing the air inside the sensor chamber to settle long enough to mitigate the reaction time of the sensors and obtain steady state. In case the flight mission needs to be adjusted, the steps of entering (A) and navigating through (B-C) the plume towards the optimal sampling position (D), and remaining there are repeated taking into account real-time updated information of the vessel's position, course and speed, meteorological conditions, and/or sampled data.

(19) Once the flight mission is completed, the UAV is returned for landing, unless the mission includes a further vessel of interest. In the latter case, the aforementioned steps of flying the UAV along the centre line of exhaust plume, determining emissions and other governing variables, transmitting sampled data and determining if the flight mission is to be adjusted are then repeated in respect of such next vessel.

(20) If at any point in time during the mission, the max flight time according to the battery is reached while still ensuring the safe return of the UAV, the mission is aborted and the UAV is returned for landing.

(21) If at any point in time from the entry into the plume (A) but prior to reaching (D) the concentration threshold is reached, the mission is deemed completed and the UAV is returned for landing, unless the mission includes a further vessel of interest.

(22) The present description provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the invention. Rather, it is to be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims.