1. A method for detecting a magnetic disturbance affecting sensor data comprising:
obtaining magnetometer sensor data from a device;
performing a plurality of magnetic disturbance detection algorithms in parallel on the sensor data; and
performing a disturbance handling routine for the sensor data when the at least one magnetic disturbance detection algorithm indicates an anomaly.
2. The method of claim 1, wherein the disturbance handling routine comprises discarding the magnetometer sensor data.
3. The method of claim 1, wherein the disturbance handling routine comprises assigning a reduced confidence index to the sensor data.
4. The method of claim 1, wherein the disturbance handling routine comprises performing a calibration procedure.
5. The method of claim 1, wherein one of the magnetic disturbance detection algorithms comprises:
determining a magnitude of a magnetic field using the magnetometer sensor data;
comparing the determined magnitude to a reference magnitude; and
detecting a disturbance in the magnetometer sensor data when a difference between the determined magnitude and the reference magnitude exceeds a threshold.
6. The method of claim 5, wherein the reference magnitude is derived from a calibration routine.
7. The method of claim 5, wherein the reference magnitude is derived from low pass filtering a plurality of samples of the magnetometer sensor data.
8. The method of claim 5, wherein the reference magnitude is derived from location information regarding a geographical position of the device.
9. The method of claim 1, wherein one of the magnetic disturbance detection algorithms comprises:
determining a three dimensional vector using the magnetometer sensor data;
determining a dip angle corresponding to an angle formed by the determined three dimensional vector and a gravity vector;
comparing the determined dip angle to a reference dip angle; and
detecting a disturbance in the magnetometer sensor data when a difference between the determined dip angle and the reference dip angle exceeds a threshold.
10. The method of claim 9, wherein the reference dip angle is derived from a calibration routine.
11. The method of claim 9, wherein the reference dip angle is derived from low pass filtering a plurality of samples of the magnetometer sensor data and accelerometer data during a motionlessness state.
12. The method of claim 9, wherein the reference dip angle is derived from location information regarding a geographical position of the device.
13. The method of claim 1, wherein one of the magnetic disturbance detection algorithms comprises:
determining an orientation of the device;
determining a three dimensional vector using the magnetometer sensor data;
rotating the determined three dimensional vector to a stationary frame using the determined orientation;
determining a two dimensional yaw angle from the rotated three dimensional vector;
comparing the determined yaw angle to a reference yaw angle; and
detecting a disturbance in the magnetometer sensor data when a difference between the determined yaw angle and the reference yaw angle exceeds a threshold.
14. The method of claim 13, wherein the reference yaw angle is derived from a calibration routine.
15. The method of claim 13, wherein the orientation of the device is determined using motion sensor data and not the magnetometer sensor data.
16. The method of claim 1, wherein one of the magnetic disturbance detection algorithms comprises:
determining an orientation of the device using sensor fusion without the magnetometer sensor data;
determining an orientation of the device using sensor fusion with the magnetometer sensor data;
comparing the orientation determined with magnetometer sensor data to the orientation determined without magnetometer sensor data; and
detecting a disturbance in the magnetometer sensor data when a difference between the orientation determined with magnetometer sensor data and the orientation determined without magnetometer sensor data exceeds a threshold.
17. The method of claim 16, further comprising identifying a change in pattern in the difference between the orientation determined with magnetometer sensor data and the orientation determined without magnetometer sensor data at a plurality of times.
18. The method of claim 16, wherein the orientation determined with magnetometer sensor data comprises a 9-axis sensor fusion and the orientation determined without magnetometer sensor data comprises a 6-axis sensor fusion.
19. The method of claim 1, wherein performing a plurality of magnetic disturbance detection algorithms on the sensor data comprises performing four magnetic disturbance detection algorithms.
20. A system for detecting a magnetic disturbance affecting sensor data comprising a magnetometer configured to output a plurality of samples of sensor data and a detection module configured to:
perform a plurality of magnetic disturbance detection algorithms in parallel on the sensor data; and
perform a disturbance handling routine for the sensor data when the at least one magnetic disturbance detection algorithm indicates an anomaly.
21. The system of claim 20, wherein the disturbance handling routine comprises discarding the magnetometer sensor data.
22. The system of claim 20, wherein the disturbance handling routine comprises assigning a reduced confidence index to the sensor data.
23. The system of claim 20, wherein the disturbance handling routine comprises performing a calibration procedure.
24. The system of claim 20, wherein the detection module is configured to perform one of the magnetic disturbance detection algorithms by:
determining a magnitude of a magnetic field using the magnetometer sensor data;
comparing the determined magnitude to a reference magnitude; and
detecting a disturbance in the magnetometer sensor data when a difference between the determined magnitude and the reference magnitude exceeds a threshold.
25. The system of claim 24, wherein the detection module is configured to derive the reference magnitude is derived from a calibration routine.
26. The system of claim 24, wherein the detection module is configured to derive the reference magnitude by low pass filtering a plurality of samples of the magnetometer sensor data.
27. The system of claim 24, wherein the detection module is configured to derive the reference magnitude from location information regarding a geographical position of the magnetometer system.
28. The system of claim 20, wherein the detection module is configured to perform one of the magnetic disturbance detection algorithms by:
determining a three dimensional vector using the magnetometer sensor data;
determining a dip angle corresponding to an angle formed by the determined three dimensional vector and a gravity vector;
comparing the determined dip angle to a reference dip angle; and
detecting a disturbance in the magnetometer sensor data when a difference between the determined dip angle and the reference dip angle exceeds a threshold.
29. The system of claim 28, wherein the detection module is configured to derive the reference dip angle from a calibration routine.
30. The system of claim 28, wherein the detection module is configured to derive the reference dip angle from low pass filtering a plurality of samples of the magnetometer sensor data and accelerometer data during a motionlessness state.
31. The system of claim 28, wherein the detection module is configured to derive the reference dip angle from location information regarding a geographical position of the system.
32. The system of claim 20, further comprising a sensor fusion module, wherein the sensor fusion module is configured to determine an orientation of the magnetometer and wherein the detection module is configured to perform one of the magnetic disturbance detection algorithms by:
determining a three dimensional vector using the magnetometer sensor data;
rotating the determined three dimensional vector to a stationary frame using the determined orientation;
determining a two dimensional yaw angle from the rotated three dimensional vector;
comparing the determined yaw angle to a reference yaw angle; and
detecting a disturbance in the magnetometer sensor data when a difference between the determined yaw angle and the reference yaw angle exceeds a threshold.
33. The system of claim 32, wherein the detection module is configured to derive the reference yaw angle from a calibration routine.
34. The system of claim 32, wherein the sensor fusion module is configured to derive the orientation of the system using motion sensor data and not the magnetometer sensor data.
35. The system of claim 20, further comprising a sensor fusion module configured to determine an orientation of the system without the magnetometer sensor data and determine an orientation of the system with the magnetometer sensor data;
wherein the detection module is configured to perform one of the magnetic disturbance detection algorithms by comparing the orientation determined with magnetometer sensor data to the orientation determined without magnetometer sensor data and detecting a disturbance in the magnetometer sensor data when a difference between the orientation determined with magnetometer sensor data and the orientation determined without magnetometer sensor data exceeds a threshold.
36. The system of claim 35, wherein the detection module is further configured to identify a change in pattern in the difference between the orientation determined with magnetometer sensor data and the orientation determined without magnetometer sensor data at a plurality of times.
37. The system of claim 35, wherein the orientation determined with magnetometer sensor data comprises a 9-axis sensor fusion and the orientation determined without magnetometer sensor data comprises a 6-axis sensor fusion.
38. The system of claim 20, wherein the detection module is configured to perform four magnetic disturbance detection algorithms.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for operating an air fractionization installation for obtaining oxygen on board an aircraft, with at least two molecular sieve chambers, the method comprising:
providing a throttle valve located in a feed conduit;
feeding a part mass flow of oxygen obtained in a respective adsorbing molecular sieve chamber for flushing a desorbing molecular sieve chamber, said adsorbing molecular sieve chamber being connected to said desorbing molecular sieve chamber via said feed conduit; and
controlling a feed cross section of said throttle valve located in said feed conduit such that a quantity of the flushing oxygen fed to the desorbing molecular sieve chamber is based on an oxygen concentration and on the mass flow of product gas delivered from said adsorbing molecular sieve chamber.
2. A method for operating an air fractionization installation according to claim 1, wherein the quantity control of the flushing oxygen fed to the desorbing molecular sieve chamber is additionally controlled by changing a plurality of feed times.
3. A method for operating an air fractionization installation according to claim 2, wherein said control means determines an opening time of said throttle valve such that said throttle valve is closed upon reaching a flushing oxygen gas quantity desorption threshold.
4. A method for operating an air fractionization installation according to claim 1, wherein said product gas is delivered to an oxygen supply of an aircraft.
5. A method for operating an air fractionization installation according to claim 1, wherein said feed cross section is reduced to a minimum feed cross section throughput when said oxygen concentration is a maximum oxygen concentration value, said feed cross section being varied such that a maximum feed cross section throughput is associated with a minimum oxygen concentration value.
6. An aircraft air fractionization installation for obtaining oxygen on board an aircraft, the air fractionization installation comprising:
a first molecular sieve chamber;
a second molecular sieve chamber, said first molecular sieve chamber and said second molecular sieve chamber defining an air fractionization structure;
a conduit supplying gas to said air fractionization structure and receiving product gas exiting from said air fractionization structure;
a feed conduit connecting said first molecular sieve chamber to said second molecular sieve chamber such that one of said chambers, as a desorbing molecular sieve chamber, is flushed with oxygen of product gas of another of said chambers, as an absorbing molecular sieve chamber;
a sensing means located downstream of said air fractionization structure for sensing oxygen concentration and mass flow of said product gas exiting from said air fractionization structure;
a throttle valve located in said feed conduit and having a throughput cross section that may be varied from a minimum to a maximum throughput;
a control means for controlling said throughput cross section to continuously vary said throughput cross section corresponding to variations in oxygen concentration and in mass flow of the product gas sensed by said sensing means, said control means controlling an amount of said product gas supplied to said desorbing molecular sieve chamber from said adsorbing molecular sieve chamber.
7. An air fractionization installation according to claim 6, wherein said control means comprises a time control by way of which the opening time of the feed valve is controlled.
8. An air fractionization installation according to claim 7, wherein said control means determines an opening time of said throttle valve such that said throttle valve is closed upon reaching a flushing oxygen gas quantity desorption threshold.
9. An air fractionization installation according to claim 6, wherein said product gas is delivered to an oxygen supply of an aircraft.
10. An air fractionization installation according to claim 6, wherein said minimum throughput is associated with a maximum oxygen concentration value, said maximum throughput being associated with a minimum oxygen concentration value.
11. A method for obtaining oxygen on board an aircraft, the method comprising:
providing a bypass conduit;
providing a throttle valve located in said bypass conduit having a variable feed cross section;
providing an air fractionization installation with a first molecular sieve chamber and a second molecular sieve chamber, said first molecular sieve chamber being in communication with said second molecular sieve chamber via said bypass conduit;
delivering gas to said air fractionization installation and providing product gas exiting from said air fractionization installation;
sensing oxygen concentration and mass flow of said product gas exiting said air fractionization installation with a sensor located downstream of said air fractionization installation;
continuously varying said feed cross section of said throttle valve based on a variation of said oxygen concentration and a variation of mass flow detected via said sensor such that one of said molecular sieve chambers as a desorbing molecular sieve chamber is flushed with oxygen of product gas of another of said chambers as an adsorbing molecular sieve chamber, whereby said feed cross section of said throttle valve controls an amount of said product gas supplied to one of said molecular sieve chambers functioning as a desorbing molecular sieve chamber from another of said chambers functioning as an adsorbing molecular sieve chamber.
12. A method for operating an air fractionization installation according to claim 11, wherein the quantity control of the flushing oxygen fed to the desorbing molecular sieve chamber is controlled by changing a plurality of feed times.
13. A method for operating an air fractionization installation according to claim 11, wherein said control means comprises at least one throttle valve with a controlled throughput cross section.
14. A method for operating an air fractionization installation according to claim 12, wherein said control means comprises a time control by way of which the opening time of the feed valve is controlled.
15. A method for operation an air fractionization installation according to claim 13, wherein said control means determines an opening time of said throttle valve such that said throttle valve is closed upon reaching a flushing oxygen gas quantity desorption threshold.
16. A method for operating an air fractionization installation according to claim 11, wherein said product gas is delivered to an oxygen supply of an aircraft.
17. A method for operating an air fractionization installation according to claim 11, wherein said throughput cross section is varied from a minimum to a maximum throughput, said minimum throughput being associated with a maximum oxygen concentration value, said maximum throughput being associated with a minimum oxygen concentration value.