CN114076600A - Navigation system and method of operation - Google Patents

Abstract

The title of the present invention is a navigation system and method of operation. A navigation system for an aircraft includes a light source, a light sensor, one or more processors, and a computer-readable medium storing instructions that, when executed by the one or more processors, cause the navigation system to perform functions. Functions include illuminating a surface with a light source to reflect light from the surface and using a light sensor to detect the light and generate data representing the light. The data maps the intensity of light to various locations on the surface. The functions further include identifying within the data a subset of the data corresponding to the boundary, and causing navigation of the aircraft based on the position of the boundary indicated by the subset of data.

Description

Navigation system and method of operation

Technical Field

The present disclosure relates generally to navigation systems and methods for operating the same, and more particularly to navigation systems of aircraft and methods for operating the same.

Background

Autonomous aircraft typically include some sort of autonomous navigation system to maneuver in the air or on the ground (e.g., during taxiing). Some conventional autonomous navigation techniques include using a visible light camera to capture successive images of a runway or another surface on which the aircraft is taxiing, and analyzing each pixel of these images to identify the runway or taxiway in these images. This can be very time consuming and computationally demanding. Additionally, such techniques may be less reliable in inclement weather such as rain or snow, or in situations of insufficient light. Accordingly, there is a need for more efficient and environmentally tolerant systems and methods for autonomous navigation of aircraft on the ground.

Disclosure of Invention

One aspect of the present disclosure is a navigation system for an aircraft, comprising: a light source; a light sensor; one or more processors; and a computer-readable medium storing instructions that, when executed by the one or more processors, cause the navigation system to perform functions comprising: illuminating the surface with a light source to reflect light from the surface; detecting light using a light sensor and generating data indicative of the light, wherein the data maps an intensity of the light to respective locations on a surface; identifying within the data a subset of the data corresponding to the boundary; and causing navigation of the aircraft based on the location of the boundary indicated by the subset of data.

Another aspect of the disclosure is a non-transitory computer readable medium storing instructions that, when executed by a navigation system of an aircraft, cause the navigation system to perform functions comprising: illuminating the surface to reflect light from the surface; detecting light and generating data indicative of the light, wherein the data maps the intensity of the light to respective locations on the surface; identifying within the data a subset of the data corresponding to the boundary; and causing navigation of the aircraft based on the location of the boundary indicated by the subset of data.

Another aspect of the disclosure is a method of operating a navigation system of an aircraft, the method comprising: illuminating the surface to reflect light from the surface; detecting light and generating data indicative of the light, wherein the data maps the intensity of the light to respective locations on the surface; identifying within the data a subset of the data corresponding to the boundary; and causing navigation of the aircraft based on the location of the boundary indicated by the subset of data.

By the term "about" or "substantially" with reference to a quantity or measurement value described herein, it is meant that the stated characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including, for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in quantities that do not interfere with the effectiveness of the feature intended to be provided.

The features, functions, and advantages that have been discussed can be achieved independently in various examples or may be combined in yet other examples in which further details can be seen with reference to the following description and drawings.

Drawings

The novel features believed characteristic of the illustrative examples are set forth in the appended claims. The illustrative examples, however, as well as a preferred mode of use, further objectives and descriptions thereof, will best be understood by reference to the following detailed description of an illustrative example of the present disclosure when read in conjunction with the accompanying drawings.

FIG. 1 is a schematic illustration of an aircraft according to an example.

Fig. 2 is a schematic block diagram of an aircraft according to an example.

Fig. 3 is a schematic block diagram of a computing system, according to an example.

FIG. 4 is a schematic illustration of an aircraft positioned on a surface according to an example.

Fig. 5A is a schematic of data corresponding to a surface, according to an example.

Fig. 5B is a schematic of data corresponding to a surface, according to an example.

Fig. 6 is a schematic of data corresponding to a surface according to an example.

Fig. 7A is a schematic diagram of data corresponding to a surface, according to an example.

Fig. 7B is a schematic of data corresponding to a surface, according to an example.

Fig. 8 is a block diagram of a method according to an example.

Fig. 9 is a block diagram of a method according to an example.

Fig. 10 is a block diagram of a method according to an example.

Fig. 11 is a block diagram of a method according to an example.

Fig. 12 is a block diagram of a method according to an example.

Fig. 13 is a block diagram of a method according to an example.

Detailed Description

As noted above, there is a need for a more efficient and environmentally resilient system and method for autonomous navigation of aircraft on a surface (e.g., the ground). In an example, a navigation system for an aircraft includes: the system includes a light source, a light sensor, one or more processors, and a computer readable medium storing instructions that, when executed by the one or more processors, cause a navigation system to perform functions. The functions include illuminating the surface with a light source to cause light to reflect from the surface, and detecting the light with a light sensor and generating data indicative of the light. The data maps the intensity of the light to various locations on the surface. The functions further include identifying a subset of data within the data (the data corresponding to a boundary between a road and a non-road, such as a runway boundary), and causing navigation of the aircraft based on a location of the boundary indicated by the subset of data.

The functionality of the navigation system described above as explained in more detail below may result in a better response time and a more efficient use of computing resources when compared to conventional navigation systems. Additionally, the disclosed navigation system may help improve performance in low light conditions and in inclement weather.

The disclosed examples will now be described in more detail below with reference to the accompanying drawings, in which some, but not all of the disclosed examples are shown. Indeed, several different examples may be described and should not be construed as limited to the examples set forth herein. Rather, these examples are described so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

FIGS. 1-7B are schematic diagrams of a navigation system and associated functionality.

FIG. 1 is an example schematic illustration of an aircraft 10 according to an example. The aircraft 10 may be or include a fixed wing aircraft, a helicopter, a rotorcraft, a drone (e.g., an unmanned airplane or satellite), a spacecraft, and so forth. The aircraft 10 includes a navigation system 100 that further includes a computing system 150 that will be described in more detail below.

Fig. 2 is a schematic block diagram of the aircraft 10. The navigation system 100 includes a light source 102 (e.g., one or more lasers) and a light sensor 104 (e.g., one or more photodetectors or photosensors). The light source 102 and the light sensor 104 are in operative communication with other components of the navigation system 100 and are typically part of a light detection and ranging system (e.g., LIDAR). The light source 102 and/or light sensor 104 may be forward-facing or aft-facing with respect to the aircraft 10, but other examples are possible.

The navigation system 100 also includes a control surface 182 and a landing gear 184. Control surfaces 182 may include, for example, flaps, rudders, ailerons. The landing gear 184 includes one or more wheels that may propel the aircraft 10 when motorized and ground traveling (e.g., taxiing).

The navigation system 100 also includes an inertial navigation system 190 that can create data 192. The inertial navigation system 190 may include one or more accelerometers and/or gyroscopes.

Fig. 3 is a schematic block diagram of a computing system 150.

Computing system 150 includes one or more processors 152, non-transitory computer-readable media 154, communication interface 156, display 158, and user interface 160. The components of the computing system 150 shown in fig. 3 are coupled together by a system bus, network, or other connection mechanism 162.

The one or more processors 152 may be any type of processor or processors, such as a microprocessor, digital signal processor, multi-core processor, or the like, coupled to a non-transitory computer-readable medium 154.

The non-transitory computer-readable medium 154 may be any type of memory, such as volatile memory like Random Access Memory (RAM), Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), or non-volatile memory like Read Only Memory (ROM), flash memory, magnetic or optical disks or compact disk read only memory (CD-ROM), as well as other devices for temporarily or permanently storing data or programs, and the like.

Additionally, the non-transitory computer-readable medium 154 may be configured to store the instructions 157. The instructions 157 are executable by the one or more processors 152 to cause the computing system 150 to perform any of the functions or methods described herein.

The non-transitory computer-readable medium 154 also stores data 206. Data 206 includes subset 210, subset 216, and subset 222 of data 206, as described in more detail below.

Communication interface 156 may include hardware to enable communication within computing system 150 and/or between computing system 150 and one or more other devices. For example, the hardware may include a transmitter, a receiver, and an antenna. Communication interface 156 may be configured to facilitate communication with one or more other devices according to one or more wired or wireless communication protocols. For example, the communication interface 156 may be configured to facilitate wireless data communication for the computing system 150 in accordance with one or more wireless communication standards, such as one or more of the Institute of Electrical and Electronics Engineers (IEEE)801.11 standard, the ZigBee standard, the bluetooth standard. As another example, communication interface 156 may be configured to facilitate wired data communication with one or more other devices.

The display 158 may be any type of display component configured to display data. As one example, display 158 may comprise a touch screen display. As another example, display 158 may include a flat panel display, such as a Liquid Crystal Display (LCD) or a Light Emitting Diode (LED) display.

User interface 160 may include one or more pieces of hardware for providing data and control signals to computing system 150. For example, the user interface 160 may include a mouse or pointing device, a keyboard or keypad, a microphone, a touchpad or touch screen, among other possible types of user input devices, and the like. In general, the user interface 160 may enable an operator to interact with a Graphical User Interface (GUI) provided by the computing system 150 (e.g., displayed by the display 158).

Fig. 4 is a schematic view of aircraft 10 positioned on surface 202. For clarity, horizon 213 is depicted. Surface 202 may include a combination of many different types of surfaces, such as a runway, taxiway, or unpaved ground, such as dirt or grass. Unpaved ground may help define the boundaries of a runway or taxiway, as unpaved ground is not considered part of a typical paved runway or taxiway.

The light source 102 of the aircraft 10 is used to illuminate the surface 202 with light 203 (e.g., laser light) to reflect the light 204 from the surface 202. The light sensor 104 detects light 204 reflected from the surface 202. Generally, a paved surface, such as a runway or taxiway, returns light 204 at a greater intensity than an unpaved surface, such as grass or dirt. Additionally, paved surfaces such as runways or taxiways generally have a unique three-dimensional shape as compared to other surfaces.

It should be noted that the terms runway and taxiway are used herein somewhat interchangeably. However, the term runway generally refers to a long, straight section of a (e.g. paved) surface for takeoff and/or landing. The term taxiway generally refers to a paved surface for taxiing aircraft from a hangar to a runway, or vice versa.

The light sensor 104 generates data 206 representative of the light 204. Data 206 maps the intensity of light 204 to various locations on surface 202. For example, data 206 includes mapping intensity values of light 204 to respective sets of three-dimensional Cartesian or spherical coordinates.

Fig. 5A is a schematic illustration of data 206 corresponding to surface 202. The navigation system 100 identifies within the data 206 a subset 210 of the data 206 that corresponds to a boundary 212. The boundary 212 generally separates a second area 260 of the paved surface on a first side of the boundary 212 from a first area 262 of the unpaved surface on a second side of the boundary 212. In fig. 5A, the boundary 212 is a line, but the boundary may be a curved boundary corresponding to a curved portion of an intersection or a runway or taxiway. Boundary 212 may take any shape and is generally any boundary that separates a runway or taxiway from an unpaved surface. The subset 210 of data 206 may be identified using statistical techniques as described below.

In other examples, the runway surface may be dirt or gravel, and the non-runway surface may be grass. In other examples, the runway surface may be distinguished from the non-runway surface by their different (e.g., painted) colors and the resulting return intensity of light 204. In still further examples, non-racetrack surfaces may also be paved. In general, a runway surface may be distinguished from a non-runway surface because the light 204 returning from the runway surface differs in intensity from the light 204 returning from the non-runway surface.

The navigation system 100 selects (e.g., randomly) arbitrary data points 244 and arbitrary data points 246 of the data 206 and determines parameters of a curve 248 (e.g., a line) that includes the arbitrary data points 244 and the arbitrary data points 246. For example, the parameters may take the form of a, b and c in the equation z ═ ax + by + c. In other examples, the curve 248 may be a circular arc, an elliptical arc, a parabola, a hyperbola, and the like. Next, the navigation system 100 determines that less than a threshold amount of data points of the data 206 conform to the curve 248 within an error range. For example, the navigation system 100 can determine that less than ten data points of the data 206 conform to the curve 248 because less than ten residuals of the data 206 are less than a threshold amount relative to the curve 248. The process of searching for a curve that fits most of the data 206 can be repeated until the navigation system 100 does find a curve that fits at least a threshold amount of the data points of the data 206.

For example, the navigation system 100 selects (e.g., randomly) arbitrary data points 236 and arbitrary data points 238 of the data 206 and determines parameters of a curve (e.g., the boundary 212) that includes the arbitrary data points 236 and the arbitrary data points 238. Next, the navigation system 100 determines that each data point of the subset 210 of the data 206 conforms to the curve (e.g., the boundary 212) within the error range and that the subset 210 of the data 206 includes at least a threshold amount of data points. That is, for example, the navigation system 100 can determine that the subset 210 includes at least ten data points of the data 206.

To additionally confirm a good fit of the curve, the navigation system 100 can determine that the subset 210 of the data 206 includes at least a threshold amount of data points per unit distance along the curve (e.g., the boundary 212). For example, the threshold amount of data points herein may be ten data points per meter along the boundary 212.

To increase additional confidence that the boundary 212 is in fact a boundary, the navigation system 100 may determine that the subset 210 of the data 206 has an average intensity of the light 204 that is greater than a threshold intensity generally corresponding to a paved surface.

In some examples, the navigation system 100 determines a parameter of a line corresponding to the boundary 212 and determines that an area 262 of the surface 202 on one side of the line has an average intensity that is less than a first threshold intensity. Additionally, the navigation system 100 determines that a region 260 of the surface 202 on the other side of the line has an average intensity greater than a second threshold intensity. In this manner, the navigation system 100 may confirm that the boundary 212 actually separates paved areas from unpaved areas, or more generally, runway areas from unpaved areas.

In some instances, the navigation system 100 also identifies the subset 278 of the data 206 that does not correspond to the boundary and deletes, filters, or ignores the subset 278 of the data 206 from further processing.

Additionally, the navigation system 100 causes navigation of the aircraft 10 (e.g., during taxiing) based on the location of the boundary 212 indicated by the subset 210 of the data 206. For example, the navigation system 100 adjusts the control surface 182 and/or the landing gear 184 based on the position of the boundary 212 indicated by the subset 210 of the data 206. In one example, the aircraft 10 is controlled to maintain a minimum distance from the boundary 212. The data 192 collected by the inertial navigation system 190 of the aircraft 10 may also assist in navigation.

The navigation system 100 can also identify a subset 216 of the data 206 that corresponds to the boundary 218. In such instances, the navigation system 100 may additionally cause navigation of the aircraft 10 based on the location of the boundary 218 indicated by the subset 216 of the data 206. For example, aircraft 10 may be controlled to remain substantially centered between boundary 212 and boundary 218. As shown in fig. 5A, boundary 218 is substantially parallel to boundary 212. Additionally, boundary 212 may be located on a first side of aircraft 10 and boundary 218 may be located on a second side of aircraft 10 opposite the first side.

Fig. 5B is a schematic diagram of a portion of data 206 corresponding to surface 202, having a more prospective perspective than fig. 5A. For clarity, FIG. 5B also includes a pictorial representation of an example runway.

Fig. 6 is a schematic diagram of the data 206 shown corresponding to the surface 202. In this example, boundary 224 intersects both boundary 212 and boundary 218 to form a dead road. In this way, the navigation system 100 identifies a subset 222 of the data 206 that corresponds to a boundary 224 that intersects the boundary 212 and the boundary 218. In this case, the navigation system 100 additionally causes navigation of the aircraft 10 based on the location of the boundary 224 indicated by the subset 222 of the data 206. For example, the aircraft 10 is controlled to turn around or stop when a dead road is encountered.

Fig. 7A is a schematic diagram illustrating data 206 mapped onto surface 202. In this example, the boundary 212 intersects the boundary 218 to form a 90 degree angle at the intersection. Other examples include boundary 212 rounded off from boundary 218.

Thus, the navigation system 100 determines the corner 230 where the boundary 212 intersects the boundary 218 and the location of the corner 230. In this case, the navigation system 100 may additionally cause navigation of the aircraft 10 based on the angle (e.g., the value of the angle) and the position of the angle. That is, the aircraft 10 may make a 90 degree right turn after passing the boundary 218. In another example, angle 230 may be 45 degrees and aircraft 10 may make a 45 degree right turn at angle 230.

Fig. 7B is a schematic of data 206 in an example where the runway surface forms a four-way intersection. The navigation system 100 additionally determines that the subset 210B of the data 206 represents the boundary 212B, determines that the subset 216B of the data 206 represents the boundary 218B, and determines the corner 230B where the boundary 212B intersects the boundary 218B and the location of the corner 230B. The navigation system 100 additionally determines that the subset 210C of the data 206 represents the boundary 212C, determines that the subset 216C of the data 206 represents the boundary 218C, and determines the corner 230C at which the boundary 212C intersects the boundary 218C and the location of the corner 230C. The navigation system 100 additionally determines that the subset 210D of the data 206 represents the boundary 212D, determines that the subset 216D of the data 206 represents the boundary 218D, and determines the corner 230D at which the boundary 212D intersects the boundary 218D and the location of the corner 230D.

In this case, navigation system 100 may additionally cause navigation of aircraft 10 based on angles 230, 230B, 230C, and/or 230D (e.g., values of angles) and the positions of angles 230, 230B, 230C, and/or 230D. That is, the aircraft 10 may make a 90 degree right turn after recognizing the four-way intersection after passing the boundary 218.

In some instances, the navigation system 100 can seek a specifically shaped intersection before performing a turn. For example, in response to recognizing a 90 degree intersection of boundary 212 and boundary 218, the aircraft 10 may be instructed to ignore the first encountered 45 degree turn, and thereafter make a 90 degree right turn at angle 230.

Fig. 8-13 are block diagrams of methods 300, 310, 314, 318, 322, and 326 for operating a navigation system of an aircraft. The methods 300, 310, 314, 318, 322, and 326 present examples of methods that may be used with the navigation system 100 shown in FIGS. 1-7. As shown in fig. 8-13, methods 300, 310, 314, 318, 322, and 326 include one or more operations, functions, or actions, as shown at blocks 302, 304, 306, 308, 312, 316, 320, 324, 328, and 330. Although the blocks are shown in sequential order, the blocks may also be performed in parallel, and/or in a different order than described herein. Moreover, various blocks may be combined into fewer blocks, divided into additional blocks, and/or removed based on a desired implementation.

Fig. 8 is a block diagram of a method 300.

At block 302, method 300 includes illuminating surface 202 to reflect light 204 from surface 202. For example, light source 102 is used to illuminate surface 202 with light 203 (e.g., laser light) to reflect light 204 from surface 202. This functionality is described in more detail with reference to fig. 4 above.

At block 304, the method 300 includes detecting light 204 and generating data 206 representative of the light 204. Data 206 maps the intensity of light 204 to various locations 208 on surface 202. For example, light sensor 104 detects light 204 reflected from surface 202 and generates data 206 representative of light 204. Data 206 maps the intensity of light 204 to various locations on surface 202. For example, data 206 includes a table that maps intensity values of light 204 to various sets of three-dimensional Cartesian or spherical coordinates. This functionality is described in more detail with reference to fig. 4, 5A, and 5B above.

At block 306, the method 300 includes identifying within the data 206 a subset 210 of the data 206 corresponding to the boundary 212. For example, the navigation system 100 identifies the subset 210 of the data 206 within the data 206. This functionality is described in more detail with reference to fig. 5A and 5B above.

At block 308, the method 300 includes causing navigation of the aircraft 10 based on the location of the boundary 212 indicated by the subset 210 of the data 206. For example, the navigation system 100 causes navigation of the aircraft 10 based on the location of the boundary 212. This functionality is described in more detail with reference to fig. 5-7 above.

Fig. 9 is a block diagram of a method 310.

At block 312, the method 310 includes identifying a second subset 216 of the data 206 corresponding to a second boundary 218. For example, the navigation system 100 identifies the second subset 216. This functionality is described in more detail with reference to fig. 5A and 5B above.

Fig. 10 is a block diagram of method 314.

At block 316, the method 314 includes identifying a third subset 222 of the data 206 corresponding to a third boundary 224 that intersects the first boundary 212 and the second boundary 218. For example, the navigation system 100 identifies the third subset 222. This functionality is described in more detail with reference to fig. 6 above.

Fig. 11 is a block diagram of method 318.

At block 320, method 318 includes determining corner 230 where first boundary 212 intersects second boundary 218 and the location of corner 230. For example, the navigation system 100 determines the angle 230 and the position of the angle 230. This functionality is described in more detail with reference to fig. 7A and 7B above.

Fig. 12 is a block diagram of a method 322.

At block 324, the method 322 includes determining that the first boundary 212 and the second boundary 218 form a particular shape. For example, the navigation system 100 determines that the boundary 212 forms a particular shape with the second runway boundary 218. This functionality is described in more detail with reference to fig. 7A and 7B above.

Fig. 13 is a block diagram of a method 326.

At block 328, the method 326 includes identifying the subset 278 of the data 206 that does not correspond to the boundary. For example, the navigation system 100 identifies the subset 278. This functionality is described in more detail with reference to fig. 5A and 5B above.

At block 330, the method 326 includes deleting the subset 278 of the data 206. For example, the navigation system 100 deletes the subset 278. This functionality is described in more detail with reference to fig. 5A and 5B above.

Examples of the present disclosure may thus relate to one of the listed terms (EC) listed below. While the scope of protection is determined by the claims that follow, the disclosure can be implemented in a number of ways, including but not limited to those in accordance with the following enumerated terms:

EC1 is a navigation system for an aircraft, comprising: a light source; a light sensor; one or more processors; and a computer-readable medium storing instructions that, when executed by the one or more processors, cause the navigation system to perform functions comprising: illuminating the surface with a light source to reflect light from the surface; detecting light using a light sensor and generating data indicative of the light, wherein the data maps an intensity of the light to respective locations on a surface; identifying a subset of the data in the data that corresponds to the boundary; and causing navigation of the aircraft based on the location of the boundary indicated by the subset of data.

EC2 is the navigation system of EC1, wherein the boundary is a first boundary, the functions further comprising: identifying a second subset of the data corresponding to the second boundary, wherein causing navigation of the aircraft comprises causing navigation of the aircraft based additionally on a second location of the second boundary indicated by the second subset of the data.

EC3 is the navigation system of EC2, wherein the second boundary is substantially parallel to the first boundary.

EC4 is the navigation system of EC2 or EC3, the functions further comprising: identifying a third subset of the data corresponding to a third boundary that intersects the first boundary and the second boundary, wherein causing navigation of the aerial vehicle comprises causing navigation of the aerial vehicle based additionally on a third location of the third boundary indicated by the third subset of the data.

EC5 is the navigation system of any one of EC2-4, wherein the first boundary is on a first side of the aircraft and the second boundary is on a second side of the aircraft opposite the first side.

EC6 is the navigation system of any one of EC2-5, wherein the first boundary intersects the second boundary.

EC7 is the navigation system of EC6, the functions further comprising: determining an angle at which the first boundary intersects the second boundary and a location of the angle, wherein causing navigation of the aircraft comprises causing navigation of the aircraft based additionally on the location and the angle.

EC8 is the navigation system of any one of EC2-7, the functions further comprising: determining that the first boundary and the second boundary form a particular shape, wherein causing navigation of the aircraft comprises causing navigation of the aircraft additionally based on determining that the first boundary and the second boundary form the particular shape.

EC9 is the navigation system of any one of EC1-8, wherein causing navigation of the aircraft comprises causing navigation of the aircraft on a surface.

EC10 is the navigation system of any one of EC1-9, wherein identifying the subset of data comprises: selecting two arbitrary data points of the data; determining a shape parameter comprising two arbitrary data points; and determining that each data point of the subset of data conforms to the shape within the error range and that the subset of data includes at least a threshold amount of data points.

EC11 is the navigation system of EC10, wherein identifying the subset of data further comprises: selecting a second two arbitrary data points of the data; determining a parameter of a second curve comprising a second two arbitrary data points; and determining that less than a threshold amount of data points of the data fit the second curve within the error range.

EC12 is the navigation system of any of EC10-11, wherein identifying the subset of data further comprises determining that the subset of data includes at least a second threshold amount of data points per unit distance.

EC13 is the navigation system of any of EC10-12, wherein identifying the subset of data further comprises determining that the subset of data has an average intensity greater than a threshold intensity.

EC14 is the navigation system of any one of EC1-13, wherein causing navigation of the aircraft comprises additionally causing navigation of the aircraft based on data collected by an inertial navigation system of the aircraft.

EC15 is the navigation system of any one of EC1-14, wherein identifying the subset of data comprises: determining parameters of a line corresponding to the boundary; determining that a first region of the surface on a first side of the line has a first average intensity that is less than a first threshold intensity; and determining that a second area of the surface on a second side of the line has a second average intensity greater than a second threshold intensity.

EC16 is the navigation system of any one of EC1-15, wherein causing navigation of the aircraft comprises adjusting control surfaces or landing gears of the aircraft based on the location of the boundary indicated by the subset of data.

EC17 is the navigation system of any one of EC1-16, wherein the subset is a first subset, the functions further comprising: identifying a second subset of data that does not correspond to the boundary; and deleting the second subset of data.

The EC18 is a non-transitory computer readable medium storing instructions that, when executed by a navigation system of an aircraft, cause the navigation system to perform functions including: illuminating the surface to cause light to reflect from the surface; detecting light and generating data indicative of the light, wherein the data maps the intensity of the light to respective locations on the surface; identifying a subset of the data in the data that corresponds to the boundary; and causing navigation of the aircraft based on the location of the boundary indicated by the subset of data.

EC19 is a method of operating a navigation system of an aircraft, the method comprising: illuminating the surface to reflect light from the surface; detecting light and generating data indicative of the light, wherein the data maps the intensity of the light to respective locations on the surface; identifying a subset of the data in the data that corresponds to the boundary; and causing navigation of the aircraft based on the location of the boundary indicated by the subset of data.

EC20 is the method of EC19, wherein identifying the subset of data comprises: selecting two arbitrary data points of the data; determining a parameter of a curve comprising two arbitrary data points; and determining that each data point of the subset of data conforms to the curve within the error range and that the subset of data includes at least a threshold amount of data points.

The description of the different advantageous arrangements has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the examples in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. Further, different advantageous examples may describe different advantages as compared to other advantageous examples. The choice and description of the selected example or examples are made to explain the principles of the examples, the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various examples with various modifications as are suited to the particular use contemplated.

Claims (15)

1. A navigation system (100) for an aircraft (10), comprising: light source (102); a light sensor (104); one or more processors (152); and A computer-readable medium (154) storing instructions (157) that, when executed by the one or more processors, cause the navigation system to perform functions including: illuminating a surface (202) with the light source to reflect light (204) from the surface; Detecting the light using the light sensor and generating data representing the light (206), wherein the data maps the intensity of the light to various locations on the surface (208); identifying a subset (210) of the data in the data that corresponds to a boundary (212); and Navigation of the aircraft is caused based on the position of the boundary indicated by the subset of data. 2. The navigation system of claim 1, wherein the boundary is a first boundary, the function further comprising: (312) identifying a second subset (216) of said data corresponding to a second boundary (218), wherein causing navigation of the aircraft includes causing navigation of the aircraft based additionally on a second location of the second boundary indicated by the second subset of data. 3. The navigation system of claim 2, wherein the second boundary is substantially parallel to the first boundary. 4. The navigation system according to claim 2 or 3, the function further comprising: (316) identifying a third subset (222) of the data corresponding to a third boundary (224) that intersects the first boundary and the second boundary, wherein causing navigation of the aircraft includes causing navigation of the aircraft based additionally on a third location of the third boundary indicated by the third subset of data. 5. The navigation system of claim 2 or 3, wherein the first boundary is on a first side of the aircraft and the second boundary is on a second side of the aircraft opposite the first side on the side. 6. The navigation system of claim 2, wherein the first boundary intersects the second boundary. 7. The navigation system of claim 6, the functionality further comprising: (320) determining a corner (230) at which the first boundary intersects the second boundary and the position of the corner, Wherein causing navigation of the aircraft includes causing navigation of the aircraft additionally based on the position and the angle. 8. The navigation system of claim 2 or 3, the function further comprising: (324) determining that the first boundary and the second boundary form a specific shape, Wherein causing navigation of the aircraft includes causing navigation of the aircraft additionally based on determining that the first boundary and the second boundary form the specific shape. 9. The navigation system of claim 1 or 2, wherein causing navigation of the aircraft comprises causing navigation of the aircraft on the surface. 10. The navigation system of claim 1 or 2, wherein identifying the subset of the data comprises: select two arbitrary data points of the data (236, 238); determining parameters of the curve including the two arbitrary data points; and It is determined that each data point of the subset of the data conforms to the shape within a margin of error and that the subset of the data includes at least a threshold amount of data points. 11. The navigation system of claim 1 or 2, wherein identifying the subset of the data comprises: determining parameters of the line corresponding to said boundary; determining that a first region (262) of the surface on a first side of the wire has a first average intensity that is less than a first threshold intensity; and A second region (260) of the surface on the second side of the line is determined to have a second average intensity greater than a second threshold intensity. 12. The navigation system of claim 1 or 2, wherein causing navigation of the aircraft comprises adjusting a control surface of the aircraft based on the position of the boundary indicated by the subset of data (182 ) or landing gear (184). 13. The navigation system of claim 1 or 2, wherein the subset is a first subset, the functionality further comprising: (328) identifying a second subset of said data that does not correspond to a boundary (278); and (330) Delete the second subset of the data. 14. A method (300) of operating a navigation system (100) of an aircraft (10), the method comprising: (302) illuminating a surface (202) to reflect light (204) from the surface; (304) detecting light and generating data (206) representing the light, wherein the data maps the intensity of the light to various locations on the surface (208); (306) identifying a subset (210) of the data in the data that corresponds to a boundary (212); and (308) Cause navigation of the aircraft based on the location of the boundary indicated by the subset of data. 15. The method of claim 14, wherein identifying the subset of the data comprises: select two arbitrary data points of the data (236, 238); determining parameters of the curve including the two arbitrary data points; and It is determined that each data point of the subset of data fits the curve within a margin of error and that the subset of data includes at least a threshold amount of data points.

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