Visual cue simulator

• US 4,276,029 A
• Filed: 05/17/1979
• Issued: 06/30/1981
• Est. Priority Date: 05/17/1979
• Status: Expired due to Term

• Current Assignee: Ohio State University
• Original Assignee: Ohio State University
• Inventors: Thurston, Marlin O., Gilson, Richard D., Olson, Karl W., Ventola, Ronald W.
• Primary Examiner(s): Grieb, William H.
• Application Number:
  US06/040,059
• Time in Patent Office: 775 Days
• Field of Search: 35/12 N, 358/104, 340/27 NA, 340/27 AT
• US Class Current: 434/43
• CPC Class Codes: G09B 9/302 the image being transformed by computer processing, e.g. updating the image to correspond to the changing point of view

Abstract

A simulator arrangement wherein visual cues are generated by a video system at a display surface (18) spaced from an eye position (14). The image at the display surface is formed as longitudinal boundaries emanating from a vanishing point (VP) positioned a predetermined distance above a fixed horizon (30) image. Hue and texture visual information are developed between the longitudinal boundaries from a memory function (178). The slopes of the longitudinal boundaries are developed as the quotient of the value of the transverse displacement of a boundary from the corresponding position of the eye position divided by a value representing simulated height of the eye position. The arrangement finds particular utilization in conjunction with flight trainers.

Claims

1. The method of simulating visual cues at a display surface positioned a distance, D, from an eye position, said cues representing portions of a simulative region having predetermined visual features defined by boundaries extending generally longitudinally outwardly from said eye position and by visual information having boundaries transversely oriented with respect to said longitudinal boundaries, said longitudinal and transverse boundaries being locatable by coordinates and said eye position having a simulated instantaneous height, H, and positions identified with respect to said coordinates, comprising the steps of:

generating a video raster and displaying said raster at said display surface;

generating signals representing the predetermined vertical location of a vanishing point within the periphery of said raster, those horizontal traces of said raster being located vertical distances designated, y, below said vanishing point;

generating slope signals, each representing the slope at said raster of said longitudinal boundary extensible from said vanishing point, said slope of a given longitudinal boundary representing a quotient substantially derived as the value of the transverse displacement of said given boundary from the corresponding position of said instantaneous eye position divided by a value representing said instantaneous height, H;

providing an addressible image information memory, each address thereof retaining an information signal representing said visual information;

addressing said memory to provide said information signals for a given said visual feature in correspondence with said eye position instantaneous height, H, its coordinate position and a said horizontal trace position, y;

generating boundary signals representing said longitudinal boundaries extending from said vanishing point at the slopes defined by said slope signals;

treating said combination of said boundary signals and said addressed information signals to provide video information signals;

processing said video information signals to generate video outputs; and

treating said video outputs to provide an image at said raster.

2. The method of claim 1 in which:

each said longitudinal boundary is displaced transversely within said region from a parallel longitudinally disposed reference line a predetermined substantially unique distance, Wn;

said eye position is located at a said instantaneous coordinate, Y_A ;

said reference line is located at a coordinate, Y_R ; and

each said slope signal is generated in correspondence with a quotient derived substantially as the value, Y_A -Y_R +Wn, divided by a value representative of said height, H.

3. The method of claim 1 wherein said slope signals are generated while said horizontal traces are located above said vanishing point.

4. The method of claim 1 wherein said image information memory is addressed by generating an address signal, KA, having as a component thereof the quotient of the value of said height, H, divided by the value of a said horizontal trace position, y.

5. The method of claim 4 wherein:

said image information memory is provided having an initial address corresponding with an outer terminal, said transversely oriented boundary which is spaced longitudinally from a reference point within said region a distance of value KN; and

said address signal, KA, is generated as the product of said quotient H/y and the value of said distance, D, said product being combined with said value, KN, and a value representing the coordinatized longitudinal distance between said reference point and said eye position.

6. The method of claim 5 in which:

each said longitudinal boundary is displaced transversely within said region from a parallel longitudinally disposed reference line a predetermined substantially unique distance, Wn;

said eye position is located at a said instantaneous coordinate, Y_A ;

said reference line is located at a coordinate position, Y_R ; and

each said slope signal is generated in correspondence with a quotient derived as the value, Y_A -Y_R +Wn, divided by a value representative of said height, H.

7. The method of claim 6 wherein said slope signals are generated while said horizontal traces are located above said vanishing point.

8. Visual display apparatus for use in a simulator system of a variety wherein visual motion cues are generated as a video raster display at a stationary display surface spaced from an eye position a distance, D, said visual cues representing portions of a simulative region having predetermined visual features defined by boundaries extending generally longitudinally outwardly from said eye position and by visual information having boundaries generally transversely oriented with respect to said longitudinal boundaries, said boundaries and instantaneous said eye positions being identifiable within a simulative coordinate system and said eye position having a simulative height, H, said apparatus comprising:

timing means for generating video raster controls including horizontal scan information and control signals developed through a predetermined digital sequence and vertical information and control signals developed through a predetermined digital sequence;

first circuit means for generating signals representing the predetermined vertical location of a vanishing point upon said raster, horizontal traces of said raster being located vertical distances, y, below said vanishing point;

second circuit means for developing slope signals each representing the slope at said raster of a said longitudinal boundary extensible from said vanishing point, said slope of a given longitudinal boundary representing a quotient substantially derived as a value representing the transverse displacement within said coordinate system of said given boundary from the corresponding position of said instantaneous eye position divided by a value representing said instantaneous height, H;

third circuit means responsive to said timing circuit means horizontal scan information signals and said slope signals for generating boundary signals representing said longitudinal boundaries extending from said vanishing point at the slopes defined by said slope signals;

fourth circuit means for treating the combination of said boundary signals and signals representing said visual information to provide video information signals; and

video processing means responsive to said video information signals for deriving video outputs for developing an image at said raster.

9. The visual display apparatus of claim 8 wherein:

each said longitudinal boundary is displaced transversely within said simulative region from a parallel longitudinally displaced reference line having a position, Y_R, a select, substantially unique distance, Wn;

said eye position is located within said coordinate system at a position Y_A, and

said third circuit means is configured to develop each said slope signal in corresondence with a quotient of the value, Y_A -Y_R +Wn,divided by a value representative of said height, H.

10. The visual display apparatus of claim 8 in which said second circuit means is configured for developing said slope signals when said horizontal traces are located above said vanishing point.

11. The visual display apparatus of claim 8 including:

image information memory means for retaining an information signal representing said visual information at a unique address;

said second circuit means is a processor having an arithmetic function for deriving a said unique address in correspondence with said eye position instantaneous height, H, its position within said coordinate system and a said horizontal trace position, y.

12. The visual display apparatus of claim 11 wherein said second circuit means is configured to derive said unique address as a signal, KA, having as a component thereof the quotient of the value of said height, H, divided by the value of a said horizontal trace position, y.

13. The visual display apparatus of claim 12 wherein:

said image information memory means is provided having an initial address corresponding with an outer, terminal, said transversely oriented boundary which is spaced longitudinally from a reference point within said region a distance of value KN; and

said second circuit means is configured to generate said address signal, KA, as the product of said quotient, H/y, and the value of said distance, D, said product being combined with said value, KN, and a value representing longitudinal distance within said coordinate system between said reference point and said eye position.

14. The visual display apparatus of claim 8 further comprising fifth circuit means for generating signals for defining a horizon extending across said raster.

15. The visual display apparatus of claim 8 in which said timing means includes:

vertical counter means for deriving said predetermined digital sequence of vertical control signals as a division by a predetermined odd number of a digital sequence of said horizontal control signals; and

control means for dividing said digital sequence of horizontal control signals by two and combining the thus divided horizontal control signals with said vertical control signals to establish a sequence of vertical blanking signals and horizontal blanking signals defining an interlaced raster frame of field 0 and field 1.

16. The visual display apparatus of claim 15 in which said first circuit means includes comparator means responsive to said vertical information signals for deriving an output signal for locating said vanishing point during a said field having an intersecting horizontal trace passing through said vanishing point, and including network means for deriving said output signal for a next succeeding field having a horizontal trace thereof located next below said intersecting horizontal trace.

17. The visual display apparatus of claim 8 wherein said third circuit means comprises:

comparator means having a first input coupled to receive said timing circuit means horizontal scan information and a second input for receiving longitudinal boundary slope increment signals and having an output for providing said boundary signals representing the digital correspondence between said first and second inputs;

adder means having a first input for receiving retained said second circuit means slope signals, a second input for receiving summed slope signals for developing a summation of said signals at said first and second inputs at an output thereof;

data selector means having a first input for receiving said adder means output summed signals and a second input for receiving a signal representing the horizontal positions of said vanishing point at said raster and selectively actuable to present a predetermined one of said first or second inputs at the output thereof;

shifter network means having an input for receiving said second circuit means slope signals and retaining them and actuable to substantially halve the value of a said slope signal corresponding with a horizontal scan first appearing below said vanishing point.

18. The visual display apparatus of claim 17 wherein said third circuit means further includes:

overflow detection means coupled with said adder means and responsive to an overflow condition thereat to inhibit the enablement thereof; and

override network means responsive to said overflow condition for inhibiting the development of a said boundary signal.

19. Visual display apparatus for use with a flight simulator system of a variety including a base supported aircraft trainer having a cockpit and front and side window-like openings for providing lines of sight from an eye location within said cockpit and having flight controls manipulative to cause said cockpit to move upon said base in roll, pitch and yaw attitudes about respective longitudinal, transverse and vertical axes, said system including a stationary display surface viewable from said eye location along said lines of sight, said surface being spaced from said eye location a predetermined distance, D, for display of a simulative terrain region as a video raster, said region being defined having predetermined visual features established by boundaries, all extending in parallel to one selected coordinate direction of a coordinate system, said selected coordinate direction being designated X, or Y, said region being further defined by visual information having boundaries transversely oriented with respect to said longitudinal boundaries, said trainer including means generating altitude signals, H, substantially representative of the height of said eye location above said terrain region and means for generating signals representing the simulated velocity of said trainer, said apparatus comprising:

timing means for generating video raster controls including horizontal scan information and control signals developed through a predetermined digital sequence and vertical information and control signals developed through a predetermined digital sequence;

first circuit means for generating signals defining the predetermined vertical location of a vanishing point representing the convergence of said longitudinal boundaries upon said raster, those horizontal traces of said raster located below said vanishing point being positioned vertical distances, y, therefrom;

second circuit means for developing slope signals each representing the slope at said raster of a said longitudinal boundary extensible from said vanishing point, said slope of a given longitudinal boundary representing a quotient substantially derived as a value representing the transverse displacement within said coordinate system of said given boundary from the corresponding position of said eye location within said coordinate system divided by a value representing said height, H, said eye position being derived from said velocity signals;

third circuit means responsive to said timing circuit means horizontal scan information signals and said slope signals for generating boundary signals representing said longitudinal boundaries extending from said vanishing point at the slopes defined by said slope signals;

fourth circuit means for treating the combination of said boundary signals and signals representing said visual information to provide video information signals; and

video processing means responsive to said video information signals for deriving video outputs for developing an image at said raster.

20. The visual display apparatus of claim 19 wherein:

said longitudinal boundaries are aligned along said X coordinate direction;

each said longitudinal boundary is displaced transversely within said simulative region from a parallel reference line having a coordinate position, Y_R, a select distance, Wn;

said second circuit means includes responsive to said velocity signals for generating the location of said eye position within said coordinate system as, Y_A, and further includes means for developing said slope signal in accordance with the expression;

##EQU8## where said velocity signals correspond with simulated flight generally along a +X coordinate direction and, in accordance with the expression;

##EQU9## where said velocity signals correspond with simulated flight generally along a -X coordinate direction.

21. The visual display apparatus of claim 19 wherein:

said longitudinal boundaries are aligned along said Y coordinate direction;

each said longitudinal boundary is displaced transversely within said simulative region from a parallel reference line having a coordinate position, Y_R, a select distance, Wn;

said second circuit means includes means responsive to said velocity signals for generating the location of said eye position within said coordinate system as, Y_A, and further includes means for developing said slope signal in accordance with the expression;

##EQU10## where said velocity signals correspond with simulated flight generally along a +Y coordinate and, in accordance with the expression;

##EQU11## where said velocity signals correspond with a simulated flight generally along a -Y coordinate.

22. The visual display apparatus of claim 19 in which said second circuit means is configured for developing said slope signals when said horizontal traces are located above said vanishing point.

23. The visual display apparatus of claim 19 including:

image information memory means, for retaining an information signal representing said visual information at a unique address;

said second circuit means is a processor having an arithmetic function for deriving said unique address in correspondence with said eye position instantaneous height, H, its position within said coordinate system and said horizontal trace position, y.

24. The visual display apparatus of claim 23 wherein said second circuit means includes means for deriving said unique address as a signal, KA, having as a component thereof, the quotient of the value of said height, H, divided by the value of a said horizontal trace position, y.

25. The visual display apparatus of claim 23 in which:

said longitudinal boundaries are aligned along said X coordinate direction;

said second circuit means is configured to derive said unique address as a signal, KA, in accordance with the expression;

space="preserve" listing-type="equation">KA=X.sub.A -X.sub.R +KN+(DH/y),

when said velocity signals represent simulated flight generally along a +X coordinate, and in accordance with the expression;

space="preserve" listing-type="equation">KA=X.sub.A -X.sub.R +KN-(DH/y),

when said velocity signals represent a simulated flight generally along a -X coordinate direction, and where, X_A represents the simulated X coordinate position of said eye position, X_R represents an X coordinate reference position fixed within said coordinate system and KN represents a distance along an X coordinate to an initial address within said image information memory means, said initial address corresponding with an outer, terminal said transverse oriented boundary which is spaced longitudinally from said reference point, X_R.

26. The visual display apparatus of claim 23 in which:

said longitudinal boundaries are aligned along said Y coordinate direction;

said second circuit means is configured to derive said unique address as a signal, KA, in accordance with the expression;

space="preserve" listing-type="equation">KA=Y.sub.A -Y.sub.R +KN+(DH/y),

when said velocity signals represent simulated flight generally along a +Y coordinate, and in accordance with the expression;

space="preserve" listing-type="equation">KA=Y.sub.A -Y.sub.R +KN-(DH/y),

when said velocity signals represent a simulated flight generally along a -Y coordinate direction, and where Y_A represents the simulated Y coordinate position of said eye position, Y_R represents a Y coordinate reference position fixed within said coordinate system and KN represents a distance along a Y coordinate to an initial address within said image information memory means, said initial address corresponding with an outer, terminal said transverse oriented boundary which is spaced longitudinally from said reference point, Y_R.

27. The visual display apparatus of claim 19 in which said timing means includes:

vertical counter means for deriving said predetermined digital sequence of vertical control signals as a division by a predetermined odd number of a digital sequence of said horizontal control signals; and

control means for dividing said digital sequence of horizontal control signals by two and combining the thus divided horizontal control signals with said vertical control signals to establish a sequence of vertical blanking signals and horizontal blanking signals defining an interlaced raster frame of field 0 and field 1.

28. The visual display apparatus of claim 27 in which said first circuit means includes comparator means responsive to said vertical information signals for deriving an output signal for locating said vanishing point deriving a said field having an intersecting horizontal trace passing through said vanishing point, and including network means for deriving said output signal for a next succeeding field having a horizontal trace thereof located next below said intersecting horizontal trace.

29. The visual display apparatus of claim 27 wherein said third circuit means comprises:

comparator means having a first input coupled to receive said timing circuit means horizontal scan information and a second input for receiving longitudinal boundary slope increment signals and having an output for providing said boundary signals representing the digital correspondence between said first and second inputs;

adder means having a first input for receiving retained said second circuit means slope signals, a second input for receiving summed slope signals for developing a summation of said signals at said first and second inputs at an output thereof;

data selector means having a first input for receiving said adder means output summed signals and a second input for receiving a signal representing the horizontal position of said vanishing point at said raster and selectively actuable to present a predetermined one of said first or second inputs at the output thereof;

shifter network means having an input for receiving said second circuit means slope signals and retaining them and actuable to substantially halve the value of a said slope signal corresponding with a horizontal scan first appearing below said vanishing point.

30. The visual display apparatus of claim 29 wherein said third circuit means further includes:

overflow detection means coupled with said adder means and responsive to an overflow condition thereat to inhibit the enablement thereof; and

override network means responsive to said overflow condition for inhibiting the development of a said boundary signal.

31. A system for aircraft flight simulation comprising:

a base supported aircraft trainer having a cockpit and front and side window-like openings for providing lines of sight from an eye location within said cockpit and having flight controls manipulative to cause said cockpit to move upon said base in roll, pitch and yaw attitudes about respective longitudinal, transverse and vertical axes, said trainer including means generating altitude signals, H, substantially representative of the height of said eye location above a simulative terrain region having predetermined visual features defined by boundaries extending generally longitudinally outwardly from said eye position and by visual information having boundaries generally transversely oriented with respect to said longitudinal boundaries, said boundaries and instantaneous said eye positions being identifiable within a simulative coordinate system for said region, said trainer including means for generating velocity signals representative of the instantaneous simulated velocity of said trainer with respect to said region;

a stationary, generally vertically oriented display surface viewable from said eye location along said lines of sight, said surface being spaced from said eye location a predetermined distance, D;

video imaging means for imaging a video raster at said display surface;

timing means for generating video raster controls including horizontal scan information and control signals developed through a predetermined digital sequence and vertical information and control signals developed through a predetermined digital sequence;

first circuit means for generating signals defining the predetermined vertical location of a vanishing point representing the convergence of said longitudinal boundaries upon said raster, those horizontal traces of said raster located below said vanishing point being positioned vertical distances, y, therefrom;

second circuit means for developing slope signals each representing the slope at a said raster of said longitudinal boundary extensible from said vanishing point, said slope of a given longitudinal boundary representing a quotient substantially derived as a value representing the transverse displacement within said coordinate system of said given boundary from the corresponding position of said instantaneous eye position divided by a value representing said instantaneous height, H, said instantaneous eye position being derived from said velocity signals;

third circuit means responsive to said timing circuit means horizontal scan information signals and said slope signals for generating boundary signals representing said longitudinal boundaries extending from said vanishing point at the slopes defined by said slope signals;

fourth circuit means for treating the combination of said boundary signals and signals representing said visual information to provide video information signals; and

video processing means responsive to said video information signals for deriving video outputs for developing an image at said raster.

32. The system of claim 31 wherein:

each said longitudinal boundary is displaced transversely within said simulative region from a parallel longitudinally displaced reference line a select substantially unique distance, Wn, said reference line having a coordinate position, Y_R ;

said second circuit means is configured to derive said eye position location within said coordinate system as, X_A, and is further configured to develop each said slope signal in correspondence with a quotient of the value, X_A -X_R +Wn, divided by a value representative of said height, H.

33. The visual display apparatus of claim 31 in which said second circuit means is configured for developing said slope signals when said horizontal traces are located above said vanishing point.

34. The system of claim 31 including:

image information memory means, for retaining an information signal representing said visual information at a unique address;

said third circuit means is a processor having an arithmetic function for deriving a said unique address in correspondence with said eye position instantaneous height, H, its position within said coordinate system and a said horizontal trace position, y.

35. The system of claim 34 wherein said second circuit means is configured to derive said unique address as a signal, KA, having as a component thereof the quotient of the value of said height, H, divided by the value of said horizontal trace position, y.

36. The system of claim 35 wherein:

said image information memory means is provided having an initial address corresponding with an outer, terminal said transverse oriented boundary which is spaced longitudinally from a reference point within said region a distance of value KN; and

said second circuit means is configured to generate said address signal, KA, as the product of said quotient, (H/y) and the value of said distance, D, said product being combined with said value, KN, and a value representing longitudinal distance within said coordinate system between said reference point and said eye position.

37. The system of claim 31 in which said timing means includes:

vertical counter means for deriving said predetermined digital sequence of vertical control signals as a division by a predetermined odd number of a digital sequence of said horizontal control signals; and

control means for dividing said digital sequence of horizontal control signals by two and combining the thus divided horizontal control signals with said vertical control signals to establish a sequence of vertical blanking signals and horizontal blanking signals defining an interlaced raster frame of field of 0 and field 1.

38. The system of claim 37 in which said first circuit means includes comparator means responsive to said vertical information signals for deriving an output signal or locating said vanishing point deriving a said field having an intersecting horizontal trace passing through said vanishing point, and including network means for deriving said output signal for a next succeeding field having a horizontal trace thereof located next below said intersecting horizontal trace.

39. The visual display apparatus of claim 37 wherein said third circuit means comprises:

comparator means having a first input coupled to receive said timing circuit means horizontal scan information and a second input for receiving longitudinal boundary slope increment signals and having an output for providing said boundary signals representing the digital correspondence between said first and second inputs;

adder means having a first input for receiving retained said second circuit means slope signals, a second input for receiving summed slope signals for developing a summation of said signals at said first and second inputs at an output thereof;

data selector means having a first input for receiving said adder means output summed signals and a second input for receiving a signal representing the horizontal position of said vanishing point at said raster and selectively actuable to present a predetermined one of said first or second inputs at the output thereof;

shifter network means having an input for receiving said second circuit means slope signals and retaining them and actuable to substantially halve the value of a said slope signal corresponding with a horizontal scan first appearing below said vanishing point.

40. The visual display apparatus of claim 39 wherein said third circuit means further includes:

overflow detection means coupled with said adder means and responsive to an overflow condition thereat to inhibit the enablement thereof; and

override network means responsive to said overflow condition for inhibiting the development of a said boundary signal.

41. Visual display apparatus for use in a simulator system of a variety wherein visual motion cues are generated as a video raster display at a stationary display surface spaced from an eye position a distance, D, said visual cues representing portions of a simulative region having predetermined visual features defined by boundaries extending generally longitudinally outwardly from said eye position and by visual information having boundaries generally transversely oriented with respect to said longitudinal boundaries, said boundaries and instantaneous said eye positions being identifiable within a simulative coordinate system and said eye position having a simulative height, H, said apparatus comprising:

timing means for generating interlaced raster controls including horizontal counter means for generating horizontal scan information and control signals developed through a predetermined digital sequence, vertical counter means for generating vertical information and control signals as a division by a predetermined odd number of a select digital sequence of said horizontal counter means, and control means for dividing said select digital sequence of said horizontal counter means by two and combining the thus divided select sequence with said vertical control signals to establish a sequence of vertical blanking signals and horizontal blanking signals defining an interlaced raster frame of field 0 and field 1;

first circuit means for generating signals representing the predetermined vertical location of a vanishing point upon said raster, horizontal traces of said raster being located vertical distances, y, below said vanishing point;

second circuit means for developing slope signals each representing the slope at said raster of a said longitudinal boundary extensible from said vanishing point;

third circuit means responsive to said timing circuit means horizontal scan information signals and said slope signals for generating boundary signals representing said longitudinal boundaries extending from said vanishing point at the slopes defined by said slope signals;

fourth circuit means for treating the combination of said boundary signals and signals representing said visual information to provide video information signals; and

video processing means responsive to said video information signals for deriving video outputs for developing an image at said raster.

42. The visual display apparatus of claim 41 wherein said third circuit means comprises:

comparator means having a first input coupled to receive said timing circuit means horizontal scan information and a second input for receiving longitudinal boundary slope increment signals and having an output for providing said boundary signals representing the digital correspondence between said first and second inputs;

adder means having a first input for receiving retained said second circuit means slope signals, a second input for receiving summed slope signals for developing a summation of said signals at said first and second inputs at an output thereof;

data selector means having a first input for receiving said adder means output summed signals and a second input for receiving a signal representing the horizontal position of said vanishing point at said raster and selectively actuable to present a predetermined one of said first or second inputs at the output thereof;

shifter network means having an input for receiving said second circuit means slope signals and retaining them and actuable to substantially halve the value of a said slope signal corresponding with a horizontal scan first appearing below said vanishing point.

43. The visual display apparatus of claim 42 wherein said third circuit means further includes:

overflow detection means coupled with said adder means and responsive to an overflow condition thereat to inhibit the enablement thereof; and

override network means responsive to said overflow condition for inhibiting the development of a said boundary signal.