WO2019063727A1

WO2019063727A1 - System and method for determining and tracking a position of a mobile device onboard an aircraft

Info

Publication number: WO2019063727A1
Application number: PCT/EP2018/076339
Authority: WO
Inventors: Michael Lüdtke; Annika EVERS
Original assignee: Airbus Operations Gmbh
Priority date: 2017-09-28
Filing date: 2018-09-27
Publication date: 2019-04-04

Abstract

A process for determining the location of a portable electronic device, such as a smartphone or tablet, within an aircraft and a portable electric device configured to determine its location. The process is based on sensors in the portable electronic device determining that movement has occurred. After having an initial starting position entered, the portable electronic device tracks its movement and determines an estimated position. An accuracy of the estimated location is improved with one or more filters, such as a particle filter. The more accurate estimated location may be displayed on the portable electronic device. The more accurate estimated location can be used to provide movement instructions to the portable electronic device or it may be used when determining which flight attendant responds to a customer service request.

Description

SYSTEM AND METHOD FOR DETERMINING AND TRACKING A

POSITION

OF A MOBILE DEVICE ONBOARD AN AIRCRAFT

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application claims the benefit of United States Provisional Patent Application No. 62/564,778 filed on September 28, 2017, the entire disclosure of which is incorporated herein by way of reference.

FIELD OF THE INVENTION

[0002] The present invention relates to a method for determining and tracking a position of a portable electronic device onboard an aircraft, and a portable electronic device used in such a process. BACKGROUND OF THE INVENTION

[0003] Localization inside an aircraft cabin has many different applications. One potential group of users of a localization system are the members of the cabin crew. Flight attendants need different information and functions on their portable electronic devices depending on their position in the aircraft. For example, the different meal wishes of the passengers in the current serving-area can be displayed. With a localization system, displaying the current positions of all crew members may also be desirable.

[0004] Outdoors, a Global Positioning System (GPS) is most often utilized for determining the position of a portable electronic device. For this technique a line of sight connection between the device and several satellites is required. Thus, it is not possible to accurately use GPS signals inside buildings or inside of an aircraft cabins as the signal strength is attenuated by walls and other materials. Accordingly, there is a need for different techniques for indoor localization inside of an aircraft cabin that do not rely on GPS for position determination.

[0005] Some processes for locating object devices, such as portable electronic devices, inside of an aircraft have been proposed which rely on or involve infrastructure. These systems require the installation of a plurality of sensors or devices in order to work and require additional hardware. In some situations, the additional hardware is not an issue; however, with respect to localization on an aircraft, it would be desirable to minimize or reduce the required infrastructure to accommodate weight and special requirements associated with aircraft.

[0006] There are several high-level requirements for systems and methods for determining the location of portable electronic devices within an aircraft cabin that would be desirable, including:

[0007] Accuracy at least to the individual seat within the aircraft cabin;

[0008] As little additional infrastructure as possible;

[0009] Compatibility with off-the-shelf or conventional portable electronic devices;

[00010] Update frequency of approximately 1 Hz; and,

[00011] Invariance against moving people and crowds of people.

[00012] The required accuracy results from the applications of the system. As mentioned above, the additional infrastructure would result in more weight in the airplane and if the system is used in the manufacturing, installing the infrastructure would require extra time for manufacturing the aircraft. A system should be compatible with off-the-shelf portable electronic devices, such as a smartphone, to reduce the need for extra hardware development and be applicable for different types of portable electronic devices. An update frequency of 1 Hz is needed for localization of a walking user due to the typical walking frequency of around 1 step per second. Finally, since, many additional people are present in an aircraft cabin, it would be desirable that their presence has minimal impact on the system. BRIEF SUMMARY OF THE INVENTION

[00013] In one or more embodiments and aspects, the present invention provides a process for determining and tracking a position of a portable electronic device onboard an aircraft that does not suffer for the aforementioned drawbacks and achieves one or more of the previously mentioned requirements. Additionally, in one or more embodiments, the present invention provides a portable electronic device used in such a process. According to the various embodiments of the present invention, the processes and portable electronic devices according to the present invention utilize the accelerometer and the gyroscope of the portable electronic devices to provide an accurate position determined for the portable electronic device.

[00014] Most portable electronic devices are equipped with many systems and sensors usable for indoor localization. The portable electronic devices include sensors like an accelerometer and a gyroscope and support wireless technologies like WLAN (IEEE 802.11), Bluetooth, NFC and mobile phone communication standards (2G, 3G, Long Term Evolution (LTE)). Additionally, portable electronic devices include a camera which can be used for image detection.

[00015] In present invention, the position of the portable electronic device in the aircraft cabin is determined by summing up the user's consecutive steps. For example, the Pedestrian Dead Reckoning (PDR) method is used. This accuracy of the location method is improved by applying a particle filter. With this filter, errors are assumed for the step length and orientation estimations and a cloud of possible locations is calculated. After applying the filter, these locations are compared to the map of the cabin. With this method, the mean error for the complex scenario can be reduced. Additionally, after checking the position against a map of the aircraft interior, different additional corrective methods, like corridor recognition and backtracking, are applied to further improve the accuracy of the location. The methods may be implemented in an application on the portable electronic device.

[00016] As mentioned at the outset, there are many different uses of location- based applications inside aircraft cabins. The main potential users of such a system are the members of the cabin crew, but applications for passengers, maintenance and aircraft production are also contemplated.

[00017] Accordingly, in at least one aspect the present invention may be broadly characterized as providing a process for determining the location of a portable electronic device within an aircraft by: receiving, by the portable electronic device, an initial starting position within the aircraft; detecting, by the portable electronic device, a movement of the portable electronic device; tracking the movement of the portable electronic device by estimating a location of the portable electronic device based on data associated with the movement of the portable electronic device; and, refining the estimated location of the portable electronic device with one or more filters to improve an accuracy of the estimated location.

[00018] The process may further include displaying the estimated location of the portable electronic device on an image of the aircraft after refining the estimated location of the portable electronic device with one or more filters. The estimated location may be displayed on the portable electronic device. [00019] In one or more embodiments, the initial starting position received by the portable electronic device is the estimated location after refining the estimated location of the portable electronic device with one or more filters.

[00020] The process may include receiving the initial starting position by capturing an image with the portable electronic device.

[00021] The process may also include receiving the initial starting position by entering a known location of the portable electronic device.

[00022] The process may also include receiving the initial starting position by using wireless techniques (WLAN, NFC...).

[00023] The process may include receiving data relating to a service request based on the estimated location after refining the estimated location of the portable electronic device.

[00024] The process may include transmitting the estimated location after refining the estimated location of the portable electronic device.

[00025] The process may include displaying movement instructions on the portable electronic device after refining the estimated location of the portable electronic device with one or more filters.

[00026] In one or more embodiments, the one or more filters comprise a particle filter. It is contemplated that the process also includes further refining the estimated location of the portable electronic device after refining the estimated location of the portable electronic device by at least one additional process selected from the group consisting of: step length correction, heading bias correction, back tracking and corridor recognition.

[00027] Accordingly, in at least one aspect the present invention may be broadly characterized as providing portable electronic device having: at least one sensor; and, a processor, of the portable electronic device, configured to receive an initial starting position within the aircraft, detect a movement of the portable electronic device, track the movement of the portable electronic device by estimating a location of the portable electronic device based on data associated with the movement of the portable electronic device, and, refining the estimated location of the portable electronic device with one or more filters to improve an accuracy of the estimated location.

[00028] The portable electronic device may also include a display. The processor may be configured to display the estimated location on an image of the aircraft after refining the estimated location of the portable electronic device with one or more filters.

[00029] The portable electronic device may also include a receiver configured to receive data, or a transmitter configured to transmit the estimated location after refining the estimated location of the portable electronic device with one or more filters, or both. The data may be movement instructions. The data may be a service request based on the estimated location after refining the estimated location of the portable electronic device.

[00030] Once again, in one or more embodiments according to this aspect, the one or more filters comprise a particle filter. It is further contemplated that the processor, is configured to further refine the estimated location of the portable electronic device after refining the estimated location of the portable electronic device by at least one additional process selected from the group consisting of: step length correction, heading bias correction, back tracking and corridor recognition.

[00031] In one or more embodiments, the at least one sensor includes an accelerometer and a gyroscope.

[00032] Advantages of the present invention will now become apparent from the detailed description with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[00033] Embodiments of the invention will now be described, by way of example only, with reference to the following drawings in which:

[00034] Figure 1 shows a schematic top view of an exemplary aircraft cabin used in accordance with the present invention;

[00035] Figure 2 shows a schematic diagram of a portable electronic device according to the present invention;

[00036] Figure 3 shows a process flow diagram of a process according to the present invention;

[00037] Figure 4 shows a process flow diagram of a portion of a process according to the present invention; and,

[00038] Figure 5 shows another process flow diagram of a portion of a process according to the present invention. DETAILED DESCRIPTION

[00039] With reference to Figure 1, the present invention relates to determining the position of one or more portable electronic devices 10 within an aircraft 12, for example within the cabin of the aircraft.

[00040] As shown in Figure 2, each portable electronic device 10 includes a processor 50, memory 52, a display screen 64, and hardware 66 (e.g., ports, interfaces, antennas, amplifiers, signal processors, etc.) for wired or wireless communication. The portable electronic devices 10 may include software 58 stored in a non-transitory medium, hardware, firmware, etc., containing executable instructions for causing the portable electronic devices 10 to perform one or more steps of example methods. Example software 58 can include an operating system running one or more applications (apps) that perform one or more steps of example methods and display data or information as well as allowing a user to enter data or information. The portable electronic devices 10 also may include a touch screen 60 or other device or user interface for allowing a user to enter data or information.

[00041] The portable electronic device 10 preferably also includes a camera 62 or other image capturing device and one or more sensors for capable of determining or detecting a movement of the portable electronic device 10, preferably an accelero meter and a gyroscope. The sensors perform the measurements in the coordinate- system of the portable electronic device 10. An accelerometer measures the linear acceleration on the sensor by determining the displacement of a proof mass. A gyroscope measures the angular velocity. [00042] Additionally, the portable electronic device 10 is configured for wireless communication and may include at least one transmitter 68 and at least one receiver 70 (or a transceiver 68, 70). In the context of the present invention, the communication may be by any means, for example, RF signals may be used for wireless communication. Among possible candidates for wireless communication standards to be implemented are the standards of the IEEE 802.11 family, i.e. wireless local area network (WLAN) standards. However, other standards may also be resorted to. For instance, the portable electronic device 10 may use any of IEEE 802.11a/b/g/n/ac and 802.11 w or the IEEE 802. lq protocol (virtual local area network, VLAN). Protocol data units (PDUs) of a first protocol may be encapsulated using a second protocol, e.g. the generic routing encapsulation protocol (GRE).

[00043] The portable electronic devices 10 may for instance be a cellular phone, for instance a smartphone, a mobile computing device, e.g. a notebook or tablet computer, a portable gaming device, an electronic maintenance device, e.g. a maintenance computer, a measurement instrument or any personal maintenance terminal (PMAT), or an electronic flight book (EFB) in case of an aircraft environment.

[00044] Returning to Figure 1, the portable electronic devices 10 may be in communication with a server 14 of the aircraft 12. The server 14, as is known, includes a processor, memory, a display screen, and hardware (e.g., ports, interfaces, antennas, amplifiers, signal processors, etc.) for wired or wireless communication. The server 14 may also include software stored in a non-transitory medium, hardware, firmware, etc., containing executable instructions for causing the portable electronic devices 10 to perform one or more steps of example methods. Example software can again include an operating system running one or more applications (apps) that perform one or more steps of example methods and display data or information as well as allowing a user to enter data or information. The server 14 also may include a touch screen or other device or user interface for allowing a user to enter data or information.

[00045] Turning to Figures 3-5, the processes 100 according to various embodiments are implemented on a portable electronic device 10 through an app or through software that may be externally hosted. The app or software obtains data or information relating to, for example, the particular aircraft layout, an assigned seat, a determined location of another portable electronic device 10, or includes at least one image, either virtual or real, that comprises a map of the layout of the cabin of the aircraft 12.

[00046] In Figure 3, the process 100 begins at the start 102. This can include powering on the portable electronic devices 10 or waking the portable electronic devices 10 from a sleep mode.

[00047] In a next step, the process 100 includes the portable electronic device 10 receiving 104 an initial starting position of the portable electronic device 10. The initial starting position may be received by a user providing a known location, for example, a specific seat. The initial starting position may be received by the portable electronic device 10 taking a photograph of a QR code at a specified/predetermined location within the aircraft or other similar process. Additionally, the initial starting position may be received via wireless communication between the portable electronic device 10 and, for example, the server 14.

[00048] Furthermore, the initial starting position received by the portable electronic device 10 may also be a location determined according to the present processes that has been stored in the portable electronic device 10 or the server 14. In other words, after the process been completed for a specific portable electronic device 10, in a second or subsequent process, the initial starting position would be the estimated location of the specific portable electronic device 10 that the process determined initially.

[00049] In a further step according to the present process 100, the portable electronic device 10, detects 106 a movement of the portable electronic device 10. This is achieved with the gyroscope and accelerometer of the portable electronic device 10.

[00050] In a following step, the process 100 includes tracking 108 the movement of the portable electronic device 10 by estimating a location of the portable electronic device 10 based on data associated with the movement of the portable electronic device 10. As mentioned above and described below, this may be achieved with a Pedestrian Dead Reckoning (PDR) which adds up the steps of the user of the portable electronic device 10. Exemplary PDR processes are shown in FIGS. 4 and 5.

[00051] The process 100 further includes a step of refining 110 the estimated location of the portable electronic device 10 with one or more filters to improve an accuracy of the estimated location. The one or more filters may include a particle filter. The process 100 may further include a step of further refining 111 the estimated location of the portable electronic device 10 after refining the estimated location of the portable electronic device 10 with at least one additional process selected from the group consisting of: step length correction, heading bias correction, back tracking and corridor recognition.

[00052] The process 100 may include a step of displaying 112 the estimated location of the portable electronic device 10 on an image of the aircraft 12 after refining the estimated location of the portable electronic device 10 with one or more filters. The estimated location may be displayed on the image of the portable electronic device 10, on another portable electronic device 10, and/or on a display associated with the server 14.

[00053] Accordingly, the process 100 may include a step of transmitting 114 the estimated location after refining the estimated location of the portable electronic device 10. The estimated location may be transmitted to the server 14 and/or another portable electronic device 10.

[00054] Additionally, the process 100 may include displaying 116 a movement instruction on the portable electronic device after refining the estimated location of the portable electronic device with one or more filters. For example, the portable electronic device 10 may display directions to an assigned seat. The directions, or movement instructions, may be determined by the portable electronic device 10 or the server 14 and transmitted to the portable electronic device 10. Experimental Examples

[00055] The present experimental examples were performed in a cabin mock-up of an A380 cabin. This environment is close to a real aircraft cabin. It measures approximate 5.5m x 20m and is separated into business and economy class. A Motorola Moto X (2^nd generation) with operating system Android 4.4.4 was used as the portable electronic device 10. It is equipped with a combined 3 -axis accelerometer and gyroscope MPU6515 from InvenSense. The acceleration and angular rate are measured with 50Hz sampling rate.

[00056] Three different routes in the cabin were analyzed for the present examples. The cabin layout and the three routes are displayed in Figure 1. The first route 20 is a 16 meters long straight line. A passenger-to-seat-scenario in the business class is the second route 22. The third route 24 is a more complex route comparable with a route of a flight attendant in service in the economy class. The second and the third routes 22, 24 start at a possible calibration point (shown as a portable electronic device 10) which is located next to the Flight Attendant Panel, the main control panel for the cabin crew, in the center of the cabin.

[00057] According to the various processes, a PDR process 200, depicted in Figure 4 was used in the present examples.

[00058] In the PDR process 200, two signal preprocessing methods 202 were utilized. One is based on simple high- and low-pass filtering of low order. The other approach uses the Fourier Transformation and requires more computational power. For an accurate system, a high sampling rate for the sensors is needed. Due to this fact, the computational effort should be minimized to facilitate real-time localization and the filtering with high- and low-pass-filters was chosen.

[00059] Furthermore, in the present PDR processes 200, two different approaches were utilized for a step detection method 204- searching for extreme values or searching for zeros. The search for extreme values is chosen because the application of thresholds is more flexible, and the extreme values are also needed for step length estimation.

[00060] The PDR method 200 also includes a step length estimation step 206. Many different processes for determining step length are known. The simplest one is a constant step length which can be used as a reference to rank the benefits of the other approaches. Other methods for step length estimation include acceleration based, frequency based, based on the bio metric inverse pendulum and two empirical methods. The model of a biometric inverse pendulum requires a specific position of the sensor which cannot be guaranteed in the case of a portable electronic device. Such a system would need an extra sensor and for this reason is not used for the comparison. The proposed empirical methods are optimized for a special scenario and hard to transfer. This transfer would require a lot of test data. Due to these facts, the acceleration-based approaches and the approaches based on the step frequency and the acceleration variance were chosen for the experimental comparison. However, the other methods could be used and implemented if desired.

[00061] The process also includes an orientation estimation step 208. According to the present processes, it is preferred that first the orientation is calculated only from the gyroscope data, for example by direct calculation of the rotation angle and axis. To improve the results, a complementary filter is utilized. The approaches are all used for the experimental phase and the benefit of the complementary filter is evaluated.

[00062] Accordingly, the PDR process is represented by the following Algorithm 1.

Algorithm 1

1: function PDR

2: High- and low-pass-filter for preprocessing

3: Looking for extreme and check thresholds for step detection

4: Update orientation by calculating rotation angle and axis from angular rate

5: Do drift correction using complementary filter once per second

6: if Step detected? then

7: Calculate step length using Kim equation

8: Get orientation sample

9: Update location

10: end if

11 : end function

[00063] A problem of using only the PDR algorithm is the propagation of errors. While the step detection 204 and the step length estimation 206 processes provide acceptable results, the orientation estimation 208 results in errors in the position estimation and these errors cannot be directly corrected with the PDR algorithm. Accordingly, one or more filters are used on the PDR data. [00064] For example, the impact of propagation of uncertainty may be reduced by applying the map layout 210 of the aircraft cabin. This process uses the special map of the aircraft cabin to correct the position estimations. This is done by applying a particle filter which uses the map to weight the particles as valid and invalid. Additional methods for improving the particle filter are also contemplated.

[00065] The basic idea of map aiding is to check the computed estimated position against a map of the movement-area (in this case the aircraft cabin). Firstly, a coordinate system for the map is defined. The x-axis of the coordinate system points crosswise the aisles and the y-axis points in the aisle-direction. The origin is placed at the beginning of the economy class in y-direction and in the center of the cabin in x-direction. According to the process, for the weighting of the particles, the validity of the particle location has to be determined.

[00066] A location is valid, if it lies inside the cabin and outside the inner rectangles of the map. This can be checked by comparing the location with the rectangle coordinates. As a second validation method, a check of the path from the old to the new position is added. If this path crosses an inner rectangle, the particle is not valid as well. For weighting, there are also different methods including, binary weighting and alterative weighting, that may be used.

[00067] As shown in Figure 5, the particle filter process 300 includes selecting an algorithm and method for resampling. For the algorithm, the SIS-algorithm or the generic resampling may be used. For the methods of resampling, three resampling methods including multinomial, stratified and systematic resampling. [00068] In addition to the particle filtering, the process contemplates one or more additional methods, as shown in Figure 5, being used to improve the accuracy of the estimated location: step length correction, heading bias correction, back tracking and corridor recognition.

[00069] In the present processes, the Kim- Approach was chosen for the estimation of step length. The particle filter can also be used to determine the proportional factor k by calibration. For this method the factor is saved for each particle. The factor is initially sampled from a normal distribution around the mean of the calibrated factors of the test persons. In a turning situation, particles with a false step length parameter are invalid. With this method the step length parameter is learned by the program during the usage. To improve this learning further, the mean trained value can be used as initial mean value if the same user starts the program again.

[00070] The particle filter can also be used to correct the heading estimation. The so-called heading bias, which is the difference between the true direction and the estimated direction, is calculated from the validity of the particles. If the user walks on a straight line and the estimated heading is correct on both sides of the corridor the same number of particles get invalid because the heading error is Gaussian. If there is a heading bias more particles become invalid on one side of the corridor. With this concept the heading bias can be calculated as the sum of the heading errors of the valid particles. To check if the user is walking in a straight line the difference between the orientation of the last step and the actual step is calculated. If this difference is below a threshold) the heading is corrected. [00071] Another approach to improve the position estimation is backtracking in which the history of each particle is stored its history. If a particle becomes invalid, the corresponding previous particles are set invalid as well. This results from the assumption that an invalid particle position has to be the result of a step from a previous invalid position. Afterwards the previous positions are updated without keeping the invalid trajectories into account. This technique is preferably applied if the number of invalid particles is below a certain threshold. If only a small number of particles are invalid, the computational effort would not be compensated by the improvement of the position.

[00072] Finally, in corridor recognition consecutive steps are compared. If a movement on a corridor is recognized, the belonging steps are corrected. The corridor correction-technique can also be combined with the particle filter.

[00073] Accordingly, a preferred algorithm implemented in the processes and the devices of the present invention is depicted in Algorithm 2.

Algorithm 2

1: function PDR

2: High- and low-pass-filter for preprocessing

3: Looking for extrema and check thresholds for step detection

4: Update orientation by calculating rotation angle and axis from angular rate

5: Do drift correction using complementary filter once per second

6: if Step detected? then 7: Calculate step length using Kim equation

8: Get orientation sample

9: if Turning situation? then

10: Calculate heading bias and correct orientation

11: end if

12: Prediction step

13: Update step (check position and weight invalid particles with 0)

14: Resampling with systematic resampling

15: Update location

16: if Corridor conditions met? then

17: Do correction

18: end if

19: end if

20: end function

[00074] The errors and confidence radius of three test of three methods - PDR, PDR with particle filter, and PDR with particle filter with additional accuracy methods are shown in TABLE 1, below.

[00075] TABLE 1

[00076] Accordingly, based on the foregoing, it is believed that the location of the portable electronic device can be estimated with the desired specificity within an aircraft cabin without GPS based positioning and by using the sensors provided in the portable electronic device.

[00077] Again, the present invention provides the ability to accurately determine the location of a portable electronic device within an aircraft. This is believed to be beneficial and provide one or more desired functionalities: tracking of people in the aircraft cabin; display of each crew members position on a screen; and location dependent services. For example, a passenger service request call would lead to an alarming or transmission of a signal only for the closest crew member. Additionally, the present invention could be used to provide a dedicated light which follows the PA passenger X in a dark aircraft cabin. Furthermore, the present invention could be used for navigating people with their portable electronic devices in the aircraft cabin, for example guiding a passenger to their assigned seat. The present invention could also find utility during assembly or installation in the final assembly line or during maintenance proceedings.

[00078] Where in the foregoing description, integers or members are mentioned which have known, obvious or foreseeable equivalents; then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present technology, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the technology that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the technology, may not be desirable, and may therefore be absent, in other embodiments. Where the term "or" has been used in the foregoing description, this term should be understood to mean "and/or", except where explicitly stated otherwise.

[00079] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms "comprise" or "comprising" do not exclude other elements or steps, the terms "a" or "one" do not exclude a plural number, and the term "or" means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

Claims

CLAIMS Claimed Is:

1. A process for determining the location of a portable electronic device within an aircraft, the process comprising:

receiving, by the portable electronic device, an initial starting position within the aircraft;

detecting, by the portable electronic device, a movement of the portable electronic device;

tracking the movement of the portable electronic device by estimating a location of the portable electronic device based on data associated with the movement of the portable electronic device; and,

refining the estimated location of the portable electronic device with one or more filters to improve an accuracy of the estimated location.

2. The process of claim 1, further comprising:

displaying the estimated location of the portable electronic device on an image of the aircraft after refining the estimated location of the portable electronic device with one or more filters.

3. The process of claim 1 or 2, wherein the estimated location is displayed on the portable electronic device.

4. The process of any one of claims 1 to 3, wherein the initial starting position received by the portable electronic device is the estimated location after refining the estimated location of the portable electronic device with one or more filters.

5. The process of any one of claims 1 to 3, wherein receiving the initial starting position comprises:

capturing an image with the portable electronic device.

6. The process of any one of claims 1 to 3, wherein receiving the initial starting position comprises:

entering a known location of the portable electronic device.

7. The process of any of the foregoing claims 1 to 6, further comprising: receiving data relating to a service request based on the estimated location after refining the estimated location of the portable electronic device.

8. The process of any of the foregoing claims 1 to 7, further comprising: transmitting the estimated location after refining the estimated location of the portable electronic device.

9. The process of any of the foregoing claims 1 to 8, further comprising: displaying movement instructions on the portable electronic device after refining the estimated location of the portable electronic device with one or more filters.

10. The process of any of the foregoing claims 1 to 9, wherein the one or more filters comprise a particle filter.

11. The process of any of the foregoing claims 1 to 10, further comprising: further refining the estimated location of the portable electronic device after refining the estimated location of the portable electronic device by at least one additional process selected from the group consisting of: step length correction, heading bias correction, back tracking and corridor recognition.

12. A portable electronic device comprising:

at least one sensor; and, a processor, of the portable electronic device, configured to receive an initial starting position within the aircraft, detect a movement of the portable electronic device, track the movement of the portable electronic device by estimating a location of the portable electronic device based on data associated with the movement of the portable electronic device, and, refining the estimated location of the portable electronic device with one or more filters to improve an accuracy of the estimated location.

13. The portable electronic device of claim 12, further comprising:

a display, and

wherein the processor is further configured to display the estimated location on an image of the aircraft on the display after refining the estimated location of the portable electronic device with one or more filters.

14. The portable electronic device of claim 12 or 13, further comprising: a receiver configured to receive data.

15. The portable electronic device of any one of claims 12 to 14, further comprising:

a transmitter configured to transmit the estimated location after refining the estimated location of the portable electronic device with one or more filters.

16. The portable electronic device of any one of claims 12 to 15, wherein the data comprises movement instructions.

17. The portable electronic device of any one of claims 12 to 16, wherein the data comprises a service request based on the estimated location after refining the estimated location of the portable electronic device.

18. The portable electronic device of any of claims 12 to 17, wherein the one or more filters comprise a particle filter.

19. The portable electronic device of any of claims 12 to 18 wherein the processor, is configured to further refine the estimated location of the portable electronic device after refining the estimated location of the portable electronic device by at least one additional process selected from the group consisting of: step length correction, heading bias correction, back tracking and corridor recognition.

20. The portable electronic device of any of claims 12 to 19 wherein the at least one sensor comprises an accelerometer and a gyroscope.

21. A portable electronic device configured to run a process according to any of claims 1 to 11.