Aircraft

Abstract

The present invention relates to an aircraft 10 including a liquid chemical tank 20, a liquid spraying device 30, an actuator 40, multiple sensors 50, and a processing device 60. The liquid chemical tank holds the liquid chemical, the liquid spraying device sprays the liquid chemical, and the actuator operates the liquid spraying device. A sensor 51 of the multiple sensors measures the speed of the aircraft. A sensor 52 of the multiple sensors measures the direction and distance of airborne particles relative to the aircraft. The processing device determines the air movement direction and distance and the air movement velocity. This determination includes utilizing the speed of the aircraft, the direction and distance of the airborne particles relative to the aircraft, and the velocity of the airborne particles relative to the aircraft. The processing device controls flight operations and / or actuators of the aircraft. Determining commands for controlling the flight operations of the aircraft and / or for controlling the actuators includes utilizing the determined air movement direction and distance and the determined air movement velocity.

Description

[Technical field]

[0001] The present invention relates to aircraft. [Background technology]

[0002] Spray drift caused by wind and wind gusts is a major problem in agricultural production. Spray droplets drift into vulnerable areas, onto bystanders, bodies of water, and onto non-target surfaces such as nearby fields. Wind speed and direction are not constant, but vary in time (seconds to hours) and spatially in all three dimensions, caused by, for example, obstacles on the ground, surface friction from the ground or crops, and thermal fluctuations in the ground and air temperature. An obstacle with a height of 1 m can generate vortices that extend up to 10 m or more downwind, and can reach a height of 2 m (depending on other factors such as wind speed), and for larger obstacles such as trees and buildings, such vortices can extend significantly further and higher. Because aircraft such as drones typically fly at heights of 1-2 meters or more and spray products from this height, even small obstacles or changes in terrain structure can have a large effect on the wind structure within the aircraft's flight path, especially when upwind effects are combined with changes in the target area (uneven terrain, patchy crop digging, lodging, etc.), which can cause the aircraft to deviate from the optimal flight path and the spray to deviate from its intended deposition target.

[0003] This issue needs to be addressed. Summary of the Invention

[0004] It would be advantageous to have a way to mitigate the effects of spray drift.

[0005] The object of the present invention is solved by the subject matter of the independent claims, further embodiments are incorporated in the dependent claims.

[0006] In one embodiment, A chemical tank; at least one liquid spray device; At least one actuator; A plurality of sensors; A processing device; An aircraft is provided, comprising:

[0007] The chemical tank is configured to hold a chemical liquid. The at least one liquid spraying device is configured to spray the chemical liquid. The at least one actuator is configured to operate the at least one liquid spraying device. At least one sensor of the plurality of sensors is configured to measure a speed of the aircraft relative to the ground. At least one sensor of the plurality of sensors is a light detection and ranging (LIDAR) sensor configured to measure a direction, distance, and velocity of airborne particles relative to the aircraft relative to a longitudinal axis of the aircraft. The processing device is configured to receive and analyze sensor data from the plurality of sensors to determine an air motion direction and distance relative to a projection of the longitudinal axis on the ground, and to determine an air motion velocity relative to the ground. The determination includes utilizing the speed of the aircraft, the direction and distance of the airborne particles relative to the aircraft relative to the longitudinal axis of the aircraft, and the velocity of the airborne particles relative to the aircraft. The processing device is configured to control at least one flight operation of the aircraft and / or control the at least one actuator. Determining at least one command for controlling at least one flight operation of the aircraft and / or determining at least one command for controlling at least one actuator includes utilizing the determined air movement direction and distance relative to a projection of the longitudinal axis onto the ground, and the determined air movement speed relative to the ground.

[0008] In other words, a Light Detection and Ranging (LIDAR) sensor housed / mounted on the aircraft detects the direction, distance, and speed of airborne particles, for example, in a range of about 1-100 meters and more around the aircraft relative to the reference frame of the aircraft, which may be moving, including areas particularly within the immediate flight path of the aircraft. The LIDAR sensor data enables a processing device to determine air motion (wind) speed and air motion (wind) direction and air motion (wind) distance based on the motion of the airborne particles over time (together with determined information of the aircraft's air motion speed and direction relative to the ground). This information is then used to control how the aircraft, which may be moving, sprays the chemical solution.

[0009] In this manner, the effects of wind-induced drift of the spray liquid can be mitigated by controlling the aircraft and / or the liquid spraying device itself, which takes into account the actual wind speed, direction, and distance. Compared to other wind sensors, LIDAR allows the sprayer to operate with a more foresight-oriented strategy, and therefore with greater precision. Thus, the aircraft can spray closer to the edges of the field and / or closer to the sidewalks, i.e. areas that should not be sprayed, and / or spraying can be performed at higher aircraft speeds and higher wind speeds than can currently be achieved, while staying within the legally required limits for the spray application operation. In this manner, it can also be avoided that certain areas are sprayed twice, while some parts of the field are not sprayed at all.

[0010] Thus, spray drift can be mitigated by considering wind direction, distance, and speed, and by combining various aspects of drift mitigation (e.g., spray height, crop leaf density, interception by off-crop leaves, droplet size distribution).

[0011] The above references to a liquid tank and a liquid do not exclude the presence of two tanks holding different liquids, or a liquid and a solid such as a powder, whose contents are then mixed and then sprayed as a liquid. Thus, at one level, the liquid tank may be a tube connected to a liquid spraying device, which sprays the liquid held within the tube, even if the two different fluids, or a fluid and a solid, are pre-mixed and then provided to the connecting tube as a liquid, which is then sprayed.

[0012] Liquid atomizer also refers to any kind or type of atomizing device such as a spray nozzle and / or a spinning disk atomizer, etc. In a preferred embodiment, liquid atomizer refers to a spinning disk (atomizer) liquid atomizer.

[0013] In examples, the term "chemical solution" refers to a liquid containing chemical and / or biologically based agricultural active ingredients, such as herbicides, insecticides, fungicides, crop nutrients, biostimulants, plant growth regulators, and the like.

[0014] In an example, controlling at least one flight operation includes varying the height of the aircraft above the ground and varying a horizontal position extending perpendicular to the aircraft's longitudinal axis above the ground or crop (as well as extending perpendicular to the vertical axis and parallel to the ground or crop).

[0015] Thus, in this manner, when the wind speed and / or direction causes more spray drift, for example laterally perpendicular to the direction of aircraft motion, the aircraft can fly lower and / or the aircraft can fly upwind if the spray drift is expected to increase as a result of increased wind speed and / or wind direction shift in a direction perpendicular to the direction of aircraft motion, which can be important when the aircraft is spraying at a field boundary and flying parallel to the boundary.

[0016] In other words, if the wind speed and direction are such that undesirable spray drift may occur, spraying may be performed at a reduced height above the ground or above the crop, resulting in less drift since the spray has less time to travel from the liquid spraying device to the ground or crop, and therefore less spray drift. Alternatively, or in combination with this drift mitigation strategy, the horizontal position of the aircraft may be changed, for example, more towards the wind if the wind speed is increasing. The distance of the air movement relative to the aircraft is also considered, for example, to mitigate turbulence in the air descending into the flight path.

[0017] In an example, at least one sensor of the plurality of sensors is configured to provide data from which a height of the aircraft above the ground or above the crop can be determined, and the processing device is configured to fly the aircraft to a height above the ground or above the crop that is dependent on a magnitude of the determined air movement velocity relative to the ground.

[0018] In this manner, the liquid spray device can be positioned in an ideal location to mitigate spray drift, taking into account wind speeds.

[0019] In an example, at least one sensor of the plurality of sensors is configured to provide data from which a horizontal position extending in a direction perpendicular to a longitudinal axis of the aircraft above the ground or crop (as well as parallel to the ground or crop) can be determined, and the processing device is configured to fly the aircraft to a horizontal position above the ground or crop that depends on a magnitude of the determined air movement velocity relative to the ground.

[0020] In this manner, the liquid spray device can be positioned in an ideal location to take into account wind speeds and avoid spray drift into undesired areas.

[0021] In an example, the processing device is configured to fly the aircraft at an altitude above the ground or crops and / or to fly the aircraft to a horizontal position above the ground or crops that depends on the magnitude of the air direction angle of the determined air motion direction relative to the projection of the longitudinal axis onto the ground.

[0022] In this manner, the liquid spray device can be ideally positioned to take into account wind direction to mitigate spray drift and / or avoid spray drift into undesirable areas.

[0023] In an example, the height above the ground or crop at which an aircraft is flown is calculated based on the air velocity relative to the ground multiplied by the cosine of the air direction angle.

[0024] In other words, the effect of crosswinds, or the wind component of the spray drift that is perpendicular to the aircraft's direction of forward motion, can be mitigated through appropriate control of the aircraft's height.

[0025] In an example, the horizontal position above the ground or crop at which the aircraft is flown is determined at least in part by the air velocity relative to the ground multiplied by the cosine of the air direction angle.

[0026] In other words, the effect of crosswinds, or the component of the wind perpendicular to the aircraft's forward motion, on spray drift into undesired areas can be mitigated through proper control of the aircraft's horizontal position relative to the ground.

[0027] In an example, the at least one actuator includes at least one activation actuator configured to cause the at least one liquid spraying device to start spraying the medicinal liquid and configured to cause the at least one liquid spraying device to stop spraying the medicinal liquid.

[0028] Thus, the at least one actuator configured to operate the at least one liquid spraying device includes at least one start-up actuator configured to cause the at least one liquid spraying device to stop spraying and to actually cause it to start spraying again.

[0029] In an example, the processing device is configured to control one or more of the at least one activation actuator to cause an equal number of the liquid spraying devices to stop spraying the chemical liquid based at least in part on a magnitude of the determined air movement velocity relative to the ground.

[0030] In this manner, when a combination of wind speed and direction results in a situation where the spray from one or more liquid spray devices may cause problematic spray drift, the devices may be turned off. Thus, for example, an aircraft may be operating at the edge of a field and wind gusts that cause the spray from the liquid spray devices to cross the field boundary may be mitigated by turning off the liquid spray devices.

[0031] In an example, the at least one actuator includes at least one spray adjustment actuator configured to control droplet size of the medical fluid sprayed by the at least one liquid spray device.

[0032] Thus, the at least one actuator configured to operate the at least one liquid spray device includes at least one spray adjustment actuator configured to control the droplet size sprayed by the at least one liquid spray device.

[0033] In an example, the processing device is configured to control one or more of the at least one spray adjustment actuator to control droplet size of the medicinal liquid sprayed by an equal number of liquid spray devices based at least in part on a magnitude of the determined air movement velocity relative to a projection of the aircraft's longitudinal axis on the ground.

[0034] In an example, the processing device is configured to increase droplet size based on an increase in the magnitude of the determined air velocity relative to the ground.

[0035] In this manner, if the wind speed and / or direction would otherwise result in problematic spray drift, the sprayed droplet size can be increased to mitigate the spray drift, as larger spray droplets experience less drift compared to smaller spray droplets.

[0036] In an example, the processing device is configured to control one or more of the at least one spray adjustment actuator to control droplet size of the liquid sprayed by the equal number of liquid spray devices based at least in part on a magnitude of an air direction angle of the determined air movement direction relative to a projection of the longitudinal axis of the aircraft on the ground, the air direction angle being an angle between the determined air movement direction of the projection of the longitudinal axis of the aircraft on the ground and the projection of the longitudinal axis of the aircraft on the ground.

[0037] In an example, droplet size is determined at least in part by the air velocity relative to the ground multiplied by the cosine of the air direction angle.

[0038] In examples, the aircraft further includes at least one sensor configured to capture at least one image above the ground or crop.

[0039] In this manner, the LIDAR data may be supplemented with one or more images acquired from the ground or surroundings above the crop. The processing device may fuse the LIDAR and image data. This is advantageous at the crop canopy-air interface where the crop canopy may interfere with the LIDAR detection.

[0040] Where it is described above that the processing unit is configured to control actuators and / or flight operations of the aircraft, this relates to the processing unit determining instructions for that control. For example, the processing unit may determine the instructions in the form of signals used to operate the actuators. For example, the processing unit may determine instructions to fly the aircraft in a particular manner. This may be in the form of signals used directly to fly the aircraft, or signals provided to a dedicated flight control unit that then flies the aircraft as required.

[0041] These aspects and examples will be apparent from and elucidated with reference to the embodiments described hereinafter. [Brief description of the drawings]

[0042] Exemplary embodiments will be described below with reference to the following drawings:

[0043] [Figure 1] FIG. 1 illustrates a schematic layout of an example aircraft. [Diagram 2] FIG. 1 is a diagram showing a schematic example of a plan view of an aircraft. [Diagram 3] FIG. 2 illustrates a schematic example of an aircraft floor plan and a 3D air motion speed and direction map. [Figure 4] FIG. 2 shows a schematic example of a rotating disk as part of an aircraft and the effect of the height of the rotating disk on spray drift. [Diagram 5] A figure showing a schematic example of a plan view of an aircraft flight route with and without flight path correction from a 3D air motion direction and air motion speed map. [Figure 6] FIG. 2 shows a schematic example of a rotating disk as part of an aircraft and the effect of changing the rotational speed of the rotating disk on the droplet size of the spray. [Figure 7] FIG. 1 shows a schematic example of the effect of droplet size of a spray on spray drift. [Figure 8]FIG. 2 is a schematic diagram of a plan view of an aircraft flight route, as well as a diagram showing adjustment of the rotational speed of a rotating disk and droplet size of a spray during flight. [Figure 9] FIG. 1 shows a schematic diagram of a plan view of an aircraft flight route and spray product swath with and without 3D air motion direction and air motion speed map correction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] FIG. 1 illustrates an example of an aircraft 10. The aircraft includes a liquid medicine tank 20, at least one liquid spraying device 30, at least one actuator 40, a plurality of sensors 50, and a processing unit 60. The liquid medicine tank is configured to hold a liquid medicine. The at least one liquid spraying device is configured to spray the liquid medicine. The at least one actuator is configured to operate the at least one liquid spraying device. At least one sensor 51 of the plurality of sensors is configured to measure the speed of the aircraft relative to the ground. At least one sensor 52 of the plurality of sensors is a light detection and ranging (LIDAR) sensor configured to measure the direction, distance, and velocity of airborne particles relative to the aircraft relative to a longitudinal axis of the aircraft. The processing unit is configured to determine the air motion direction and distance relative to a projection of the longitudinal axis onto the ground and determine the air motion velocity relative to the ground. This determination includes utilizing the speed of the aircraft, the direction and distance of the airborne particles relative to the aircraft relative to the longitudinal axis of the aircraft, and the velocity of the airborne particles relative to the aircraft. The processing device is configured to control at least one flight operation of the aircraft and / or control at least one actuator, and determining at least one command for controlling the at least one flight operation of the aircraft and / or determining at least one command for controlling the at least one actuator includes utilizing the determined air movement direction and distance relative to a projection of the longitudinal axis onto the ground and the determined air movement speed relative to the ground.

[0045] In an example, the at least one sensor 51 configured to measure the speed of the aircraft relative to the ground includes a GPS system.

[0046] In an example, the at least one sensor 51 configured to measure the speed of the aircraft relative to the ground includes a laser reflectivity-based system.

[0047] In an example, at least one sensor 52 is a LIDAR sensor. A LIDAR sensor is configured to measure wind (air motion) speed and direction over a range of distances. LIDAR is based on the principle of light detection and ranging. The application of this technology uses Doppler shift (change in wavelength) to determine the speed difference of backscattered light from airborne particles and is known as Doppler LIDAR. Distance is determined from the time delay from the light pulse from the laser, which is calculated from the speed of light in air (pulsed laser technology). The relative speed to the aircraft is determined from the frequency shift of the reflected laser pulse. By scanning the pulse over the target space and combining all the information, a 3D wind (air motion) direction, distance, and speed map can be obtained, and by continuously scanning the target space, the 3D wind direction, distance, and speed map can be continuously updated to obtain a near real-time map of how the wind is moving around and especially in front of the aircraft.

[0048] In an example, at least one sensor 52 is a Doppler LIDAR sensor.

[0049] In an example, the LIDAR sensor is configured to measure the direction, distance, and velocity of airborne particles relative to the aircraft relative to the aircraft's longitudinal axis in the form of a three-dimensional (3D) cone (three-dimensional volume) extending toward the aircraft's flight direction.

[0050] In an example, a LIDAR sensor uses a continuous wave (CW) laser and a 2D camera sensor array according to the Scheimpflug principle. In this system, the sensor array is angled relative to the laser beam, allowing a wide range of distances to be focused on simultaneously. This is commonly referred to as Scheimpflug LIDAR or SLIDAR. The advantages of this are that it is much smaller, a simpler laser can be used, and it is easier to mount on an aircraft.

[0051] The sensor may use synthetic array heterodyne detection (SAHD), which overcomes the need for an array detector.

[0052] In examples, the wavelength of light used in LIDAR can range, for example, from 200 nm up to 2500 nm and beyond, with wavelengths between 600 nm and 2000 nm being preferred, and even more particularly outside the visible range of 900 nm to 2000 nm where eye safety is improved.

[0053] In an example, the LIDAR signal is generated by a phased array. The advantages of a solid-state phased array are its small size, long lifetime, and low energy requirements, making it ideal for mounting on aircraft.

[0054] In examples, the LIDAR signal detection ranges range from less than 1 m to more than 1 km. Preferred airborne particle and air movement distance detection ranges for the present invention are from 1 meter up to 500 meters, more preferably from 1 meter up to 100 meters.

[0055] In examples, the airborne particles include one or more of aerosols, dust particles, vegetation particles, litter particles, and small objects.

[0056] In an example, at least one liquid atomizer is a spinning disk liquid atomizer.

[0057] According to an example, controlling at least one flight operation includes varying the height of the aircraft above the ground or crop, or the horizontal position extending perpendicular to the aircraft's longitudinal axis above the ground or crop (and in a direction parallel to the ground or crop).

[0058] In an example, controlling the at least two flight operations includes varying the height of the aircraft above the ground or crop, and (preferably simultaneously) varying the horizontal position of the aircraft above the ground or crop, extending in a direction perpendicular to the longitudinal axis of the aircraft (and parallel to the ground or crop).

[0059] According to an example, at least one sensor 53 of the plurality of sensors is configured to provide data from which a height of the aircraft above the ground or crop can be determined, and the processing device is configured to fly the aircraft to a height above the ground or crop that depends on the magnitude of the determined air movement speed relative to the ground.

[0060] In an example, the sensor used to determine the height is a radar sensor.

[0061] In an example, the sensor used to determine the height is a laser time-of-flight sensor.

[0062] According to an example, at least one sensor 54 of the plurality of sensors is configured to provide data from which a horizontal position extending in a direction perpendicular to a longitudinal axis of the aircraft above the ground or crop can be determined, and the processing device is configured to fly the aircraft to a horizontal position above the ground or crop that depends on a magnitude of the determined air movement rate relative to the ground.

[0063] In an example, the sensor used to determine the horizontal position is a GPS system.

[0064] In an example, the at least one sensor 55 is configured to determine a height of the liquid spraying device above the ground or crops. For example, the liquid spraying device may be movable relative to the body of the aircraft, for example, mounted on a telescoping extension under the aircraft.

[0065] According to an example, the processing device is configured to fly the aircraft at an altitude above the ground or crops and / or to fly the aircraft to a horizontal position above the ground or crops that depends on the magnitude of the air direction angle of the determined air movement direction relative to the projection of the longitudinal axis onto the ground.

[0066] By way of example, the height above the ground or crop at which an aircraft is flown is calculated based on the air velocity relative to the ground multiplied by the cosine of the air direction angle.

[0067] According to an example, the horizontal position above the ground or crop at which the aircraft is flown is determined based at least in part on the air velocity relative to the ground multiplied by the cosine of the air direction angle.

[0068] In an example, the processing device is configured to fly the aircraft at an altitude above the ground or crops and / or to fly the aircraft to a horizontal position above the ground or crops that depends on the determined air movement direction and distance relative to the projection of the aircraft's longitudinal axis onto the ground and the determined air movement speed relative to the ground.

[0069] In an example, the processing unit is configured to fly the aircraft downward when the magnitude of the determined air movement velocity relative to the ground exceeds one or more thresholds.

[0070] In this manner, spraying can continue in a predetermined manner until the wind speed exceeds a predetermined magnitude, and then when spray drift may become an issue, corrective action can be taken for this situation. This saves energy and also reduces the possibility of hunting, where the system may continue to search for the optimal setting.

[0071] In an example, the processing unit is configured to fly the aircraft in an upwind horizontal position when the magnitude of the determined air velocity relative to the ground exceeds one or more thresholds.

[0072] In an example, the one or more thresholds depend on the magnitude of an air direction angle, which is the angle between a determined air motion direction relative to the ground and a projection of the aircraft's longitudinal axis onto the ground.

[0073] In an example, the one or more thresholds are a plurality of thresholds, where a threshold of the plurality of thresholds is determined based on a predetermined air velocity multiplied by a cosine of an air direction angle.

[0074] In an example, the at least one liquid spray device is movably mounted on the aircraft. At least one sensor 56 of the plurality of sensors is configured to provide data from which an angle of the at least one liquid spray device relative to a vertical axis can be determined. The at least one actuator 40 includes at least one first rotor actuator 43 configured to rotate the at least one liquid spray device by at least one rotation angle relative to the vertical axis. The processing device is configured to control one or more of the at least one first rotor actuator to rotate one or more of the at least one liquid spray device.

[0075] In an example, the horizontal axis extends in a direction perpendicular to the longitudinal axis of the aircraft and perpendicular to the vertical axis. At least one sensor 57 of the plurality of sensors is configured to provide data from which an angle of the at least one liquid spray device relative to the horizontal axis can be determined. The at least one actuator 40 includes at least one second rotor actuator 44 configured to rotate the at least one liquid spray device through at least one rotation angle relative to the horizontal axis. The processing device is configured to control one or more of the at least one second rotor actuator to rotate one or more of the at least one liquid spray device.

[0076] In an example, the processing device is configured to control at least one first rotor actuator to rotate the at least one liquid spray device in unison through the same rotational angle about a vertical axis.

[0077] In an example, the processing unit is configured to control the at least one second rotor actuator to rotate the at least one liquid spray device in unison through the same rotational angle relative to a horizontal axis.

[0078] In an example, controlling the at least one actuator by the processor includes utilizing a magnitude of the determined air velocity relative to the ground.

[0079] In an example, controlling the at least one actuator by the processing unit includes utilizing a magnitude of an air direction angle of the determined air motion direction relative to a projection of the longitudinal axis on the ground, the air direction angle being an angle between the determined air motion direction of the projection of the longitudinal axis on the ground and a projection of the longitudinal axis of the aircraft on the ground.

[0080] In an example, the at least one rotation angle relative to the vertical axis is based at least in part on the air velocity relative to the ground multiplied by the cosine of the air direction angle.

[0081] In an example, controlling the at least one actuator by the processing unit includes utilizing the determined air movement direction and distance relative to a projection of the aircraft's longitudinal axis onto the ground, and the determined air movement speed relative to the ground.

[0082] According to an example, the at least one actuator includes at least one start-up actuator 41 configured to start the at least one liquid spraying device from spraying the medicinal liquid and configured to stop the at least one liquid spraying device from spraying the medicinal liquid.

[0083] According to an example, the processing device is configured to control one or more of the at least one activation actuator to cause an equal number of the liquid spraying devices to stop spraying the chemical liquid based at least in part on a magnitude of the determined air movement velocity relative to the ground.

[0084] In an example, the processing device is configured to control one or more of the at least one actuation actuator to stop an equal number of the liquid spraying devices from spraying the liquid based at least in part on a magnitude of an air direction angle of the determined air movement direction relative to a projection of the longitudinal axis on the ground, the air direction angle being an angle between the determined air movement direction of the projection of the longitudinal axis on the ground and a projection of the longitudinal axis of the aircraft on the ground.

[0085] In an example, the decision to stop the liquid spraying device from spraying is based at least in part on the air velocity relative to the ground multiplied by the cosine of the air direction angle.

[0086] In an example, the decision by the processing device to stop the liquid spray device from spraying includes utilizing the determined air movement direction and distance relative to the projection of the aircraft's longitudinal axis onto the ground, and the determined air movement speed relative to the ground.

[0087] According to an example, the at least one actuator includes at least one spray adjustment actuator 42 configured to control droplet size of the medicinal liquid sprayed by the at least one liquid spray device. In an example, the at least one spray adjustment actuator is configured to control droplet size by varying the rotation speed or revolutions per minute (RPM) of the at least one liquid spray device when the at least one liquid spray device is a rotating disk (atomizer) liquid spray device.

[0088] In an example, the at least one spray adjustment actuator is configured to control droplet size by varying liquid pressure in the at least one liquid spray device when the at least one liquid spray device includes a spray nozzle.

[0089] In an example, the processing device is configured to control at least one spray adjustment actuator to control droplet size of the spray based at least in part on a determined air movement direction and distance relative to a projection of the aircraft's longitudinal axis on the ground and a determined air movement speed relative to the ground.

[0090] According to an example, the processing device is configured to control one or more of the at least one spray adjustment actuator to control droplet size of the medicinal liquid sprayed by an equal number of liquid spray devices based at least in part on a magnitude of the determined air movement velocity relative to a projection of the longitudinal axis of the aircraft on the ground.

[0091] According to an example, the processing device is configured to control one or more of the at least one spray adjustment actuator to increase droplet size based on an increase in the magnitude of the determined air movement velocity relative to the ground.

[0092] According to an example, the processing device is configured to control one or more of the at least one spray adjustment actuator to control droplet size of the medicinal liquid sprayed by the equal number of liquid spray devices based at least in part on a magnitude of an air direction angle of the determined air movement direction relative to a projection of the longitudinal axis of the aircraft on the ground, the air direction angle being an angle between the determined air movement direction of the projection of the longitudinal axis of the aircraft on the ground and the projection of the longitudinal axis of the aircraft on the ground.

[0093] According to an example, droplet size is determined at least in part by the air velocity relative to the ground multiplied by the cosine of the air direction angle.

[0094] In an example, the at least one liquid spraying device is movably mounted to the aircraft. The at least one liquid spraying device is configured to be moved away from and towards the body of the aircraft. The at least one actuator includes at least one extended actuator 45 configured to move the at least one liquid spraying device away from and towards the body of the aircraft. Controlling the at least one actuator includes controlling the at least one extended actuator to vary a height of the at least one liquid spraying device above the ground or crops.

[0095] In an example, the liquid spray device is mounted on an extendable and retractable mount directly below the aircraft, allowing the distance between the liquid spray device and the body of the aircraft to be varied. Thus, the aircraft can be flown at a constant height above the ground or crops, and the height of the liquid spray device above the ground or crops can be varied. In this manner, if the likelihood of spray drift increases, one way to mitigate this is to spray from a lower height by varying the height of the liquid spray device but maintaining the aircraft at an optimal flying height. The liquid being sprayed is then in the air for a reduced time, and as a result has less time to drift sideways, thereby mitigating spray drift.

[0096] In an example, a sensor measures the distance of the liquid spray device below the body of the aircraft, and therefore, by knowing the height of the body of the aircraft from the ground or crop through the use of an appropriate sensor, the height of the liquid spray device from the ground or crop can be determined.

[0097] In an example, at least one sensor 58 of the plurality of sensors is configured to provide data from which a height of the at least one liquid spray device above the ground or crop can be determined, and the processing device is configured to control the at least one extension actuator to position the at least one liquid spray device at a height above the ground or crop that is dependent on a magnitude of the determined air movement velocity relative to the ground or crop.

[0098] In an example, the processing unit is configured to control at least one extension actuator based at least in part on a determined air movement direction and distance relative to a projection of the aircraft's longitudinal axis on the ground, and a determined air movement speed relative to the ground.

[0099] In the example, the sensor 58 used to determine height is a radar sensor.

[0100] In the example, the sensor 58 used to determine height is a laser time-of-flight sensor.

[0101] In an example, the processing device is configured to control at least one extension actuator to position the at least one liquid spraying device at a height above the ground or crop that depends on the magnitude of the air direction angle of the determined air movement direction relative to the projection of the front-to-rear axis onto the ground.

[0102] In an example, the height above the ground or crop at which the at least one liquid spray device is positioned is calculated based on the air velocity relative to the ground multiplied by the cosine of the air direction angle.

[0103] In an example, the processing device is configured to control the at least one extension actuator to move the at least one liquid spray device downwardly when a magnitude of the determined air movement velocity relative to the ground exceeds one or more thresholds.

[0104] In an example, the one or more thresholds depend on the magnitude of an air direction angle, which is the angle between a determined air motion direction relative to the ground and a projection of the aircraft's longitudinal axis onto the ground.

[0105] According to an example, the one or more thresholds are a plurality of thresholds, one of which is determined based on a predefined air velocity multiplied by a cosine of an air direction angle.

[0106] According to an example, the aircraft further includes at least one sensor 59 configured to capture at least one image above the ground or crops.

[0107] In an example, the sensor 59 is a camera. The processing unit can fuse / supplement the data from the LIDAR sensor and the camera image data to continuously generate updated wind (air motion) speed, distance, and direction in the local vicinity of the aircraft. This is advantageous at the crop canopy-air interface where the crop canopy may interfere with the LIDAR detection.

[0108] Another embodiment of the invention relates to a system including the aircraft of the invention and a base station. The base station may include other components, such as a weather station, and / or a wireless or wired interface to a LIDAR sensor, for example located at the edge of a field. This has the advantage that necessary actions can be planned much ahead of the aircraft, especially when terrain features (e.g. high hedgerows, rolling fields) interfere with the line of sight required for the LIDAR. It also means that a high-resolution map of weather conditions over a field can be built without an aircraft, facilitating future planning.

[0109] 2 shows a plan view of an exemplary aircraft 10 flying over and spraying crops in a field. The aircraft is flying close to and parallel to the field boundary, and the wind is blowing with a component towards the boundary. The aircraft is traveling at a speed V S The plane is flying at a speed of V AG The wind is blowing at a velocity of 1000 Hz. The aircraft has a LIDAR sensor to determine (based on detection of the motion of airborne particles over time) the direction, distance, and speed of the wind relative to the aircraft, in other words, at a reference from the aircraft. Due to the movement of the aircraft, the measured wind direction, distance, and speed are all distorted from their true ground values, as shown. Thus, the wind speed measured at the aircraft is V AV However, vector-based analysis can be used to determine the actual ground wind direction, distance, and speed. In this manner, the component of the wind speed toward the field boundary can be determined with respect to the ground. The aircraft's processing device can then position its liquid spraying device closer to the ground or crop if the wind is too strong and the wind direction and distance result in lateral drift, and / or the processing device can control the liquid spraying device itself to spray larger droplets that are not subject to drifting or tilting the liquid spraying device into the wind. The aircraft can also move horizontally toward the windward direction to avoid drifting into undesired areas. It has been found that the absolute speed of the aircraft relative to the spray is not particularly important. This is because the spray has a forward speed equal to the forward speed of the aircraft, but the spray is very quickly delayed and then falls under gravity at a speed governed by the drag from the air and is carried globally by the moving air, i.e., the wind.

[0110] However, spray can also be entrained by air downwash from the aircraft rotor blades.

[0111] Therefore, the following situation may apply, where the aircraft takes appropriate measures to mitigate the effects of spray drift: The wind therefore has a wind speed that has a component blowing perpendicular to the forward direction of the aircraft. This component of the wind speed is V AG1 The processor flew the aircraft slightly downwards. This strategy was determined to be optimal in that spray drift was not an issue and was not blown over the boundary. However, the wind is increasing in terms of wind speed, so now the component of wind speed perpendicular to the forward direction is increased by a value V AG2 In this example, the processor mitigates the effect of drift into undesirable regions that would otherwise occur by steering the aircraft further toward an upwind location where it has been determined that there is less drift into undesirable regions. AG3 As the wind gusts further to a lateral component having ...

[0112] FIG. 3 shows a schematic example of an aircraft plan view, as well as a 3D air motion speed and air motion direction map. The aircraft 10, exemplarily represented by a quadrocopter, flies in the direction of the arrow as depicted at the bottom left of the aircraft. The aircraft's LIDAR sensor 52 detects information about the speed, direction, and distance of airborne particles relative to the aircraft relative to the aircraft's longitudinal axis (and over time). Together with information about the aircraft's speed relative to the ground, the processing unit determines a 3D air motion speed ahead of the aircraft, as well as an air motion direction and distance map, all in three dimensions. In FIG. 3, only two dimensions are shown on the right (arrows extending in the direction of the x-axis and y-axis). The length of the arrow correlates with the wind (air motion) motion speed, and the direction of the arrow correlates with the wind (air motion) motion direction at a particular spatial location. The position of the arrow within the LIDAR sensor data cone correlates with the wind (air motion) distance. The continuously updated 3D air motion velocity and air motion direction and distance maps are used for aircraft flight operations and / or to control the liquid spray device.

[0113] FIG. 4 shows a schematic example of a rotating disk as an example of a liquid spraying device 30 as part of an aircraft, and the effect of the height of the rotating disk 30 on spray drift. The rotating disk is located under the aircraft's propeller, and the dotted line shows the connection to other parts of the aircraft (not shown). In example (a), spray drift occurs because the aircraft flies too high above the ground or crop for the wind speed, direction, and distance shown. In example (b), spray drift is reduced because the aircraft flies at a reduced height above the ground or crop for the wind speed, direction, and distance shown. In this example, the droplet size of the spray liquid in example (a) and example (b) is the same.

[0114] FIG. 5 shows schematic examples of plan views of aircraft flight routes with and without flight path correction from 3D air motion direction, distance, and air motion speed maps. An aircraft 10, exemplarily represented by a quadrocopter, flies in the direction of the arrow as depicted on the left. In example (a), the flight route is shown without any flight route correction due to local air motion direction, distance, and air motion speed. The spray width deposition on the agricultural land of this flight route is depicted in (c). In example (b), the flight route is shown with flight route correction (e.g., correction in the horizontal position of the aircraft) due to local air motion direction, distance, and air motion speed. The spray width deposition on the agricultural land of this flight route is depicted in (d), which is more accurate than the spray width deposition as shown in (c).

[0115] FIG. 6 shows a schematic example of a rotating disk as an example of a liquid spraying device 30 as part of an aircraft, and the effect of changing the rotational speed of the rotating disk on the droplet size of the sprayed liquid. The rotating disk is located under the propeller of the aircraft, and the dotted lines indicate the connection to other parts of the aircraft (not shown). On the left side, the rotational speed of the rotating disk 30 is high (high v r ), fine droplets are sprayed. On the right side, the rotation speed of the rotating disk 30 is low (low v r ), coarse droplets are sprayed.

[0116] 7 shows a schematic example of the effect of droplet size of the spray liquid on spray drift. A rotating disk as an example of a liquid spray device 30 is located under the propeller of an aircraft, and the dotted lines indicate the connection to other parts of the aircraft (not shown). When coarse droplets are generated by the rotating disk 30, there is less drift under similar wind conditions compared to fine droplets generated by the same rotating disk 30 (where the rotation speed of the rotating disk is higher).

[0117] Figure 8 shows a schematic diagram of the plan view of the flight route of an aircraft, as well as the adjustment of the rotation speed of the spinning disk during flight and the droplet size of the spray liquid. The aircraft 10, exemplarily represented by a quadrocopter, flies in the direction of the arrow as depicted on the left. In (a), it is shown how the spinning disk speed is corrected during the flight route. In spatial positions where higher air motion directions and air motion velocities occur, the speed of the spinning disk is reduced, which results in coarse liquid spray droplets being atomized as shown in (b).

[0118] FIG. 9 shows a schematic diagram of the plan view of the flight route of an aircraft, and the spray product deposition width with and without 3D air motion direction, distance, and air motion speed map correction. In example (a), the aircraft 10, exemplarily represented by a quadrocopter, flies in the direction of the arrow as depicted, without any flight route correction based on the 3D air motion direction, distance, and air motion speed map. As a result, many areas of spray deposition have either no deposition (indicated by the sign "-" in the figure) or two spray depositions (indicated by the sign "+" in the figure). In example (b), the aircraft 10 flies in the direction of the arrow as depicted, with flight route correction based on the 3D air motion direction, distance, and air motion speed map. As a result, few areas of spray deposition have either no deposition or too much deposition.

[0119] While the present invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description is to be considered illustrative or exemplary and not restrictive. The present invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the dependent claims.

[0120] In the claims, the term "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. A single processor or other device may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims are not to be construed as limiting the scope.

Claims

1. An aircraft (10), comprising: A chemical tank (20); At least one liquid spray device (30); At least one actuator (40); A plurality of sensors (50); A processing device (60); Including, The chemical tank is configured to hold a chemical; the at least one liquid spray device is configured to spray the medicinal liquid; the at least one actuator is configured to operate the at least one liquid spray device; At least one sensor (51) of the plurality of sensors is configured to measure a velocity of the aircraft relative to the ground; at least one sensor (52) of the plurality of sensors is a Light Detection and Ranging (LIDAR) sensor configured to measure distance, direction, and velocity of airborne particles relative to the aircraft relative to a longitudinal axis of the aircraft; the processing device is configured to receive and analyze sensor data from the plurality of sensors to determine an air movement direction and distance relative to a projection of the longitudinal axis on the ground and to determine an air movement velocity relative to the ground, the air movement direction and distance relative to a projection of the longitudinal axis on the ground and the air movement velocity relative to the ground being determined utilizing a speed of the aircraft, a direction and distance of the airborne particle relative to the aircraft relative to the longitudinal axis of the aircraft, and the velocity of the airborne particle relative to the aircraft; the processing device is configured to control at least one flight movement of the aircraft and / or control at least one actuator, and at least one command for controlling the at least one flight movement of the aircraft and / or at least one command for controlling the at least one actuator is determined utilizing the determined air movement direction and distance relative to a projection of the longitudinal axis on the ground and the determined air movement speed relative to the ground. aircraft.

2. 2. The aircraft of claim 1, wherein controlling the at least one flight operation includes varying a height of the aircraft above the ground or crop and a horizontal position of the aircraft above the ground or crop extending in a direction perpendicular to the longitudinal axis.

3. 3. An aircraft as claimed in claim 1 or 2, wherein at least one sensor (53) of the plurality of sensors is configured to provide data from which a height of the aircraft above the ground or crop can be determined, and the processing unit is configured to fly the aircraft to a height above the ground or crop that depends on a magnitude of the determined air movement speed relative to the ground.

4. 4. The aircraft of claim 1, wherein at least one sensor (54) of the plurality of sensors is configured to provide data from which a horizontal direction extending perpendicular to the longitudinal axis of the aircraft above the ground or crop can be determined, and the processing device is configured to fly the aircraft to a horizontal position above the ground or crop that depends on a magnitude of the determined air movement speed relative to the ground.

5. 5. An aircraft as claimed in claim 3 or 4, wherein the processing unit is configured to fly the aircraft at an altitude above the ground or crops and / or to a horizontal position above the ground or crops depending on a magnitude of an air direction angle of the determined air movement direction relative to a projection of the longitudinal axis on the ground.

6. 6. The aircraft of claim 5, wherein the height above the ground or crop at which the aircraft is flown is calculated based on the air velocity relative to the ground multiplied by the cosine of the air direction angle.

7. 6. The aircraft of claim 5, wherein a horizontal position above the ground or crop at which the aircraft is flown is determined at least in part by the air velocity relative to the ground multiplied by the cosine of the air direction angle.

8. 8. The aircraft of any one of claims 1 to 7, wherein the at least one actuator comprises at least one start-up actuator (41) configured to cause the at least one liquid spraying device to start spraying the chemical liquid and configured to cause the at least one liquid spraying device to stop spraying the chemical liquid.

9. 9. The aircraft of claim 8, wherein the processing unit is configured to control one or more of the at least one actuation actuator to cause an equal number of liquid spray devices to stop spraying the chemical liquid based at least in part on a magnitude of the determined air movement velocity relative to the ground.

10. 10. The aircraft of claim 1, wherein the at least one actuator comprises at least one spray adjustment actuator (42) configured to control a droplet size of a liquid medicament sprayed by the at least one liquid spray device.

11. 11. The aircraft of claim 10, wherein the processing unit is configured to control one or more of the at least one spray adjustment actuator to control the droplet size of the liquid sprayed by an equal number of liquid spray devices based at least in part on a magnitude of the determined air movement velocity relative to a projection of the longitudinal axis of the aircraft on the ground.

12. The aircraft of claim 11 , wherein the processing unit is configured to increase the droplet size based on an increase in the magnitude of the determined air velocity relative to the ground.

13. 13. The aircraft of claim 10, wherein the processing device is configured to control one or more of the at least one spray adjustment actuator to control the droplet size of the liquid sprayed by an equal number of liquid spraying devices based at least in part on a magnitude of an air direction angle of the determined air movement direction relative to a projection of the longitudinal axis of the aircraft on the ground, the air direction angle being an angle between the determined air movement direction relative to a projection of the longitudinal axis of the aircraft on the ground and a projection of the longitudinal axis of the aircraft on the ground.

14. 14. The aircraft of claim 13, wherein the droplet size is determined at least in part by the air velocity relative to the ground multiplied by the cosine of the air direction angle.

15. The aircraft of any one of claims 1 to 14, further comprising at least one sensor (55) configured to acquire at least one image above the ground or crop.

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