Head worn display integrity monitor system and methods

• US 9,785,231 B1
• Filed: 09/26/2013
• Issued: 10/10/2017
• Est. Priority Date: 09/26/2013
• Status: Active Grant

• Current Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Zimmerman, Kenneth A., Tiana, Carlo L., Barber, Sarah
• Primary Examiner(s): Eurice, Michael J
• Application Number:
  US14/038,597
• Time in Patent Office: 1,475 Days
• CPC Class Codes: G02B 2027/0167 Emergency system, e.g. to prevent injuries
• CPC Class Codes: G02B 2027/0187 slaved to motion of at least a part of the body of the user, e.g. head, eye
• CPC Class Codes: G02B 2027/0198 System for aligning or maintaining alignment of an image in a predetermined direction
• CPC Class Codes: G02B 27/0093 with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G06F 11/1487 using N-version programming
• CPC Class Codes: G06F 11/1637 using additional compare functionality in one or some but not all of the redundant processing components
• CPC Class Codes: G06F 11/1641 where the comparison is not performed by the redundant processing components
• CPC Class Codes: G06F 3/012 Head tracking input arrangements
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors

Abstract

A head worn display system (e.g., helmet mounted (HMD) display system, and an eye wear mounted display system,) can include a combiner, a head position sensor and a computer. The computer provides symbology in response to first sensor input values associated with the head position. The symbology can be conformal with a real world scene. A monitoring system includes a redundant head position sensor for providing second sensor input values associated with head position. The computer monitors for positional accuracy of the symbology by comparing symbology calculated using the first and second input sensor values or by using an inverse function to compare sensor values.

Claims

1. In a head worn display system comprising a display, a first head position sensor for providing a plurality of first sensor input values and a computer, the display comprising a combiner, the computer comprising a display generation processor and a display monitor processor, the display generation processor causes a plurality of display symbology to be displayed on the combiner in response to the first sensor input values associated with head position, the display symbology being conformal with a real world scene and being located at a plurality of first symbology positions on the combiner, a monitoring system comprising:

the display monitor processor, wherein the display monitor processor is independent of the display generation processor, the display monitor processor calculating a plurality of second symbology positions associated with locations on the combiner calculated in response to a plurality of second sensor input values; and

a redundant head position sensor for providing the second sensor input values associated with the head position, the redundant head position sensor being a separate device from the first head position sensor, wherein a comparator of the computer compares the first symbology positions of the display symbology calculated using first independent hardware components of the display generation processor responding to the first sensor input values with the second symbology positions associated with the locations on the combiner calculated using second independent hardware components of the display monitor processor responding to the second sensor input values to determine if the first symbology positions and the second symbology positions are within a tolerance, and the comparator disabling the display of the display if the first symbology positions and the second symbology positions are not within the tolerance.

2. The monitoring system of claim 1 wherein the redundant head position sensor uses different head tracking technology than the first head position sensor.

3. The monitoring system of claim 1 wherein the computer uses an inverse algorithm and compares a plurality of third sensor input values with the first sensor input values, the third sensor input values being calculated from data associated with the display symbology using the inverse algorithm.

4. The monitoring system of claim 1 wherein the computer uses an inverse algorithm and compares a plurality of third sensor input values with the second sensor input values, the third sensor input values being calculated from data associated with the display symbology using the inverse algorithm.

5. The monitoring system of claim 1 wherein the computer uses an inverse algorithm and compares a plurality of third sensor input values with the first sensor input values and the second input sensor values to determine whether the third sensor input values are within a tolerance of the second sensor input values and the first sensor input values, the third sensor input values being calculated from data associated with the symbology using the inverse algorithm.

6. The monitoring system of claim 1 wherein an inverse algorithm is performed on a plurality of third independent hardware components.

7. The monitoring system of claim 1 wherein the first sensor input values comprise head yaw, pitch, and roll values.

8. The monitoring system of claim 7 wherein the head yaw, pitch, and roll values are combined with aircraft yaw, pitch, and roll values provided by an INS or AHRS to cause the combiner to provide the display symbology conformal with the real world scene.

9. The monitoring system of claim 8 wherein the head yaw, pitch, and roll values and aircraft yaw, pitch, and roll values are combined using an Euler transformation matrix and referenced to a ground frame.

10. A method of monitoring a plurality of symbology provided on a combiner of a display, the symbology being conformal with a scene viewable through the combiner and being provided in response to a plurality of first sensor input values using a display generation processor, the first sensor input values being associated with head position and being provided from a first head tracker sensor, the method comprising:

calculating using a display monitor processor a plurality of second sensor input values associated with the head position from a plurality of first symbol position data associated with the symbology using an inverse algorithm, the display monitor processor being independent from the display generation processor;

calculating using the display monitor processor a plurality of second symbol position data using a plurality of third sensor input values associated with the head position from a second head tracker sensor;

comparing the first sensor input values with the second sensor input values and the second symbol position data and the first symbol position data to determine if an error exists; and

disabling the display in response to the error.

11. The method of claim 10 wherein the display is disabled by a comparator.

12. The method of claim 10 wherein the display monitor processor uses a different software routine than the display generation processor to calculate the second symbol position data using a plurality of second independent hardware components separate from a plurality of first independent hardware components associated with the display generation processor.

13. The method of claim 12 wherein the first sensor input values and the second sensor input values comprise a head yaw, pitch, and roll values.

14. The method of claim 13 wherein the second sensor input values are provided using the second head tracker sensor operating according to a different technology than the first head tracker sensor providing the first sensor input values.

15. The method of claim 14 wherein the head yaw, pitch, and roll values and aircraft yaw, pitch, and roll values are combined using an Euler transformation matrix and referenced to a ground frame to determine the symbology.

16. In a head worn display system for providing a plurality of symbology on a combiner of a display in response to a plurality of first sensor input values according to a first processing operation, the first sensor input values associated with head position, the symbology being conformal with a scene viewable through the combiner, an error detection method comprising:

receiving a plurality of second sensor input values associated with the head position, the second sensor input values being from a source different than the first sensor input values;

receiving a plurality of first symbol positions associated with the symbology provided on the combiner;

processing the first symbol positions in accordance with a second processing operation representing an inverse function of the first processing operation to provide calculated sensor values;

processing using the second sensor input values to determine a plurality of second symbol positions;

comparing the calculated sensor values to the first sensor input values or to the second sensor input values and comparing the first symbol positions and the second symbol positions to determine an error; and

disabling the display in response to the error.

17. The method of claim 16 wherein the first and second sensor input values comprise a head yaw, pitch, and roll values and wherein the calculated sensor values are compared to the first sensor input values and the second sensor input values.

18. The method of claim 16 wherein the source for the first sensor input values uses a different sensing technology than the source for the second sensor input values.

19. The method of claim 16 wherein

the second symbol positions are calculated from the second sensor input values using a third processing operation on hardware independent from hardware used for the first processing operation.

20. The method of claim 19 wherein the first and second sensor input values are used in the first and third processing operations, respectively.