IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0492000
(1990-03-12)
|
발명자
/ 주소 |
- Zweifel, Terry L.
- Barrios, J. Rene
|
출원인 / 주소 |
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
4 인용 특허 :
3 |
초록
▼
A method and apparatus for simulating a windshear. A vortex is modelled in terms of a family of concentric streamlines and the position of an aircraft is defined with respect to the vortex as the aircraft traverses a reference plane. Four or more vortices are used to generate streamlines which match
A method and apparatus for simulating a windshear. A vortex is modelled in terms of a family of concentric streamlines and the position of an aircraft is defined with respect to the vortex as the aircraft traverses a reference plane. Four or more vortices are used to generate streamlines which match those encountered in an actual microburst. Each vortex placed above the simulated ground level is matched by a vortex of equal strength but opposite rotation placed below the simulated ground level at a distance equal but opposite to the height of the vortex above the ground. Strengths, distance from the vortex center, and height of the vortex may be programmed by the user. The high degree of flexibility permits accurate reproduction of the winds generated by actual microbursts for testing and developing microburst detection devices. The use of an algorithm which may be dynamically varied as a function of aircraft position obviates the need for simulating by discrete windshear magnitude as in conventional predetermined windshear tables and minimizes data storage requirements.
대표청구항
▼
1. A method for testing the effectiveness of a windshear alerting and flight guidance system for airborne use, by dynamically modelling the magnitude of a microburst windshear encounter with the aid of a digital computer and by generating a test signal to establish an alarm threshold at which it is
1. A method for testing the effectiveness of a windshear alerting and flight guidance system for airborne use, by dynamically modelling the magnitude of a microburst windshear encounter with the aid of a digital computer and by generating a test signal to establish an alarm threshold at which it is prudent to provide a warning of rapidly changing winds, comprising: providing said computer with a stored program, said stored program comprising a plurality of vortex models, each such model representing a particular plurality of concentric streamlines varying in strength, displacement relative to each other vortex model, and location of a center of each vortex model, providing said computer with digital signals defining a desired vortex model configuration, said digital signals representative of at least a predetermined strength, height of a vortex center above a ground plane, a reference altitude with respect to said ground plane corresponding to a desired point of windshear encounter, a reference distance along said ground plane at said desired point of windshear encounter, and a distance of said vortex center from a given point of origin on said ground plane, processing said digital signals in said computer to derive a further digital signal corresponding to thee vector value of a horizontal windshear component at said desired point of encounter, providing said digital computer with a further stored program, said further stored program comprising a predetermined flight path of an aircraft, processing said further stored program in said digital computer continuously to derive digital signals representative of vertical and horizontal positions of said aircraft along said flight path, applying said derived aircraft positional signals to said digital computer to vary dynamically said signal corresponding to the vector value of a horizontal wind component and a vertical wind component in accordance with said flight path, applying said dynamically varied signal to said windshear alerting and flight guidance system to activate an alarm indicating detection of a windshear, and adjusting said windshear alerting and flight guidance system to establish an alarm threshold corresponding to predetermined values of said vertical and horizontal windshear components at which a stall condition of said aircraft is imminent. 2. The method as set forth in claim 1, further comprising the steps of applying said dynamically varied signal to vary said magnitude of a first vortex with respect to a time duration. 3. The method as set forth in claim 2, further comprising the step of varying the center of said first vortex with respect to said point of origin. 4. The method as set forth in claim 3, further comprising the step of defining said derived model so as to vary said magnitude inversely as to the radial distance from the center of said first vortex, and defining a radial distance within said first vortex wherein said magnitude decreases linearly from a first predetermined value to a null value at said first center of said first vortex. 5. The method as set forth in claim 4, wherein said derives model is defined by: computing a velocity Vy along a first coordinate representative of a first vector component of said velocity at a given one of said predetermined points, and computing a velocity Vx along a second coordinate representative of a second vector component of said velocity at said given one of said predetermined points. 6. The method as set forth in claim 5, further comprising the steps of: modelling said first vortex at a predetermined magnitude and first direction of rotation, wherein said first vector has a center at a predetermined distance from said origin along said ground plane and a predetermined altitude from said ground plane, modelling a second vortex having a center at a predetermined distance from said center of said first vortex along said ground plane and at said predetermined altitude, and having a second direction of rotation opposing said first direction of rotation, modelling a third vortex below said ground plane as a mirror image of said first vortex, and modelling a fourth vortex below said reference plane as a mirror image of said second vortex. 7. The method as set forth in claim 6, further comprising the step of linearly aligning a plurality of centers of said first, second, third and fourth vortices in a plane, and defining said flight path or said aircraft at a given angle of its longitudinal axis with respect to said plane of vortices. 8. In a windshear threshold calibration apparatus, having an output for activating a windshear alerting and alarm system, the improvement comprising: means for simulating the effect of microbursts on said windshear alerting and alarm system, said means comprising a stored program representing a plurality of associated windshear vortices, means for selecting a particular set of windshear conditions represented by a combination of said windshear vortices, means for simulating the flight path of an aircraft, means for combining said simulated flight path and said combination of windshear conditions to address a digital computer for dynamically determining substantially in real time the windshear condition at each point of said flight path, and means responsive to an output of said digital computer for generating a signal for activating said windshear alerting and alarm system when said aircraft encounters a predetermined windshear condition modified by said aircraft position and said set of windshear conditions, said predetermined windshear condition representative of a predetermined hazardous flight condition. 9. Windshear calibration apparatus as set forth in claim 8, comprising: means for modeling a given vortex representative of a continuum of variations in air velocity at predetermined points with respect to a reference plane and a reference point of origin, means for defining said simulated flight path of the aircraft with respect to said given vortex, means for applying a control signal to selectively vary the magnitude of said given vortex at said predetermined points, and means for utilizing the defined position of said aircraft to determine the velocity components of said given vortex encountered by said aircraft as it traverses said reference plane. 10. The apparatus as set forth in claim 9, further comprising: means for providing a signal representative of a predetermined altitude of a center of said given vortex, means for providing a signal representative of a predetermined distance from said center of said given vortex along said ground plane distal to said point of origin, means for providing a signal corresponding to a predetermined parameter representative of the magnitude of said given vortex. means for providing a signal representative of the altitude of said aircraft with respect to said ground plane, and means for providing a signal representative of the distance of said aircraft from said point of origin to said center of said given vortex along said ground plane. 11. The apparatus as set forth in claim 10, further comprising: first summation means responsive to said altitude signals corresponding to the position of said given vortex and said flight path of said aircraft for providing an algebraic sum thereof, second summation means responsive to said distance signals corresponding to the position of said given vortex and said flight path of said aircraft for providing an algebraic sum thereof, first multiplier means for providing a product of said algebraic sum of said first summation means, second multiplier means for providing a product of said algebraic sum of said second summation means, third summation means responsive to said first and second products for providing an algebraic sum thereof, limiter means responsive to said third summation means for providing at least a predetermined summation value irrespective of said applied algebraic sum, first divider means responsive to said first summation means and said limiter means for providing a quotient thereof, second divider means responsive to said second summation means and said limiter means for providing a quotient thereof, third multiplier means responsive to said signal representative of the magnitude of said given vortex and said quotient of said first divider means for providing a product signal thereof, said product signal representative of a first vector component of said given vortex in accordance with a distance from said point of origin along the plane of said reference plane, and fourth multiplier means responsive to said magnitude of said given vortex and said quotient of said second divider means for providing a product signal thereof, said product signal representative of a vector component of said given vortex in accordance with said altitude of said aircraft. 12. The apparatus as set forth in claim 11, wherein said vector component in accordance with the distance from said point of origin along the plane of said reference plane is defined by the relationship ##EQU## and said vector component in accordance with said altitude said aircraft is defined by the relationship ##EQU## where Vx is the magnitude of a horizontal component of a vortex, Vy is the magnitude of a vertical component of the vortex, a is the distance along the reference plane from the point of origin to the center of the vortex, h is the altitude from the reference plane to the center of the vortex, x is an arbitrary point in the vortex corresponding to the distance of the aircraft from the point of origin along the reference plane, y is an arbitrary point in the vortex corresponding to the altitude of the aircraft with respect to the reference plane. 13. The apparatus as set forth in claim 9, wherein said means for applying a control signal to selectively vary the magnitude of said given vortex comprises means for varying said magnitude in accordance with a predetermined function of time. 14. The apparatus as set forth in claim 13, further comprising: clock means for providing a clock signal representative of an actual duration of time, start time means for providing a signal corresponding to a desired starting time for varying the magnitude of said given vortex, end time means for providing a signal corresponding to a desired end time for terminating the variation in magnitude of said given vortex, first summation means responsive to said clock signal and said starting time signal for providing a signal in accordance with an algebraic sum thereof, second summation means responsive to said clock signal and a predetermined time signal for providing a signal in accordance with an algebraic sum thereof, first limiter means responsive to said first summation means for providing a null output when said start time signal exceeds said actual time signal, for providing an output having a value proportional to a predetermined elapsed time interval when said actual time signal is at least equal to said start time signal and for providing an output value of unity when said actual time exceeds said predetermined time interval, first multiplier means responsive to a predetermined magnitude of said given vortex and said output of said first limiter means for providing a product thereof, third summation means responsive to said second summation means and to said end time signal for providing a signal in accordance with an algebraic sum thereof, second limiter means responsive to said third summation means for producing an output value of unity when said algebraic sum of said third summation means has a value less than zero, for producing an output inversely proportional to a further predetermined time interval when said algebraic sum of said third summation means is equal or greater than zero, and for producing a null output when said sum of said third summation means exceeds said further predetermined time interval, and second multiplier means responsive to said product produced by said first multiplier means and to said second limiter means, for providing a product thereof, said product providing a time varying output signal representative of a time varying microburst. 15. The apparatus as set forth in claim 9, further comprising means for modelling a plurality of said vortices comprising: means representative of first and third vortices located on opposing sides of said reference plane and having corresponding streamlines of equal magnitude and opposing directions each of said vortices having a center at a given altitude with respect to said reference plane and a given displacement along said reference plane with respect to said point of origin, and means representative of second and fourth vortices located on opposing sides of said reference plane and having corresponding streamlines of equal magnitude and opposing directions, said streamlines of said first vortex further opposing said streamlines of said second vortex, said streamlines of said third vortex further opposing said streamlines of said fourth vortex, said third and fourth vortices being colocated below said reference plane with respect to said first and second vortices in mirror image thereof. 16. The apparatus as set forth in claim 15, further comprising: user input means for providing a plurality of control signals defining vortex magnitude and location of a vortex with respect to said reference plane and said point of origin, said user input means adapted for simultaneously providing at leas two sets of said plurality of control signals, and for providing a signal defining thee location of said aircraft with respect to said vortex, said user input means comprising means for applying one of si two sets of said control signals corresponding to predetermined values of altitude, magnitude and direction, and distance from the point of origin along the reference plane to said first vortex, means for applying said signals corresponding to predetermined values of altitude, magnitude, direction and distance from the point of origin along the reference plane to said third vertex and means for inverting said altitude and direction signals so as to generate said third vortex as a mirror image of said first vortex. said user input means further comprising means for applying a further one of said two sets of control signals corresponding to further predetermined values of altitude, magnitude and direction, and distance from the point of origin along the reference plane to said second vortex, means for applying said further one set of control signals corresponding to said further predetermined values of altitude, magnitude and direction, and distance from the point of origin along the reference plane to said fourth vortex, and means for inverting said further values of altitude and direction signals so as to generate said fourth vortex as a mirror image of said second vortex, first summation means responsive to vertical components of said first, second, third and fourth vortices for providing an algebraic sum thereof representative of the vector summation of said vertical components, and second summation means responsive to horizontal components of said first, second, third and fourth vortices for providing an algebraic sum thereof representative of the vector summation of said horizontal components. 17. The apparatus as set forth in claim 16, wherein said aircraft traverses said centers of said vortices at an oblique angle, and said vortices are aligned with their centers substantially in a plane, further comprising: means for providing a longitudinal wind component in accordance with the function ##EQU##V L =V T cosineβ where V L is the wind magnitude along the flight path V T is the total wind magnitude formed by vector summation of the vertical and horizontal components, β is the angle between the vertical plane containing the flight path and the plane of the centers of the vortices, and means for providing a cross-wind component in accordance with the function ##EQU##V c =V T sinβ where Vc is the cross wind component. 18. The apparatus as set forth in claim 17, further comprising: user input means for providing a signal in accordance with the angle of the flight path of the aircraft with respect to said plane of the centers of the vortices, means responsive to said user input signal for deriving a cosine function of said flight path angle, means responsive to said user input means for deriving a sine function of said flight path angle, means responsive to said first and second summation means for providing the vector sum of said horizontal and vertical components of said plurality of vortices and deriving a magnitude thereof, first multiplier means responsive to said cosine function and said derived vector magnitude for providing a product thereof, said product comprising a longitudinal windshear component along the flight path of the aircraft, and second multiplier means responsive to said sine function and said derived vector magnitude for providing a product thereof, said product comprising a cross-wind windshear component with respect to the flight path of the aircraft.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.