VTOL craft deceleration control system

Claim 2

In an apparatus by means of which the flight of a V/STOL type craft may be controlled along a descent path to a hover or landing termination point, including a flight director device comprising means for providing a signal representative of actual craft velocity, means for providing a desired velocity signal variable in accordance with a predetermined velocity program from an initial value, selectable from a range of values representative of velocities at which the craft may be made to fly at a range greater than a predetermined range from the termination point, to a final value representative of a predetermined lower velocity to be attained substantially at said termination point, means responsive to the actual velocity and programmed desired velocity signals for producing an output indicative of craft attitude required to reduce the actual velocity of the craft in accordance with said velocity program, means for providing a signal indicative of a predetermined range to the termination point, and means responsive to the range indicative signal for initiating said velocity program.

Claim 3

The apparatus of claim 1 wherein the desired velocity signal is varied as a linear function of time to produce a constant deceleration of the craft.

Claim 4

The apparatus of claim 1 wherein the desired velocity signal is varied as a non-linear function of time such that the craft velocity linearly decreases without decreasing range to the termination point.

Claim 5

The apparatus of claim 1 wherein the means for providing a desired velocity signal includes means for varying the desired velocity signal as a linear function of time as the craft proceeds down the descent path from the predetermined range to a prescribed range point at which the desired velocity signal is therafter varied as a non-linear function of time so as to cause the craft velocity to decrease linearly with decreasing range to the termination point.

Claim 6

The apparatus of claim 1 including means for providing a signal representative of the craft pitch attitude and means for combining said signal representative of the craft pitch attitude with the actual velocity and variable desired velocity signals.

Claim 7

The apparatus of claim 5 wherein the means for providing a desired velocity signal includes means for varyinG the desired velocity signal as a linear function of time as the craft proceeds down the descent path from the predetermined range to a presribed range point at which the desired velocity signal is thereafter varied as a non-linear function of time so as to cause the craft velocity to decrease linearly with decreasing range to the termination point.

Claim 8

The apparatus of claim 6 including means for providing a signal indicative of craft displacement from a glide slope beam representative of the desired descent path of the craft, and means responsive to the glide slope displacement signal for producing an output representative of vertical motion required to maintain the craft on the glide slope beam.

Claim 9

Apparatus for controlling the flight of a V/STOL type craft along a descent path to a hover or landing termination point, comprising means for providing a signal representative of a desired velocity, selectable from a range of desired velocity signal values, during the initial part of the descent at a range greater than a predetermined range from the terminal point, means for providing a variable reference signal variable from an initial value representative of velocity at least equal to the maximum selectable desired velocity at a range greater than the predetermined range to a final value representative of a predetermined lower velocity, means for varying the reference signal from the initial to the final value, as the craft proceeds along the descent path, commencing at the predetermined range from the termination point, means for selecting as a reference signal from the desired velocity and variable reference velocity signals the signal which is instantaneously representative of lower velocity, means for providing a signal representative of the actual velocity of the craft, and means responsive to the actual velocity and selected instantaneous velocity signals for producing an output indicative of craft attitude required to reduce the actual velocity to the predetermined lower velocity substantially at said termination point.

Claim 10

Apparatus for controlling the flight of a V/STOL type craft along a descent path to a hover or landing termination point, comprising means for providing a signal representative of a desired velocity, selectable from a range of desired velocity signal values, during the initial part of the descent at a range greater than a predetermined range from the terminal point, means for providing a variable reference signal variable from an initial value representative of velocity at least equal to the maximum selectable desired velocity at a range greater than the predetermined range to a final value representative of a predetermined lower velocity, means for varying the reference signal from the initial to the final value, as the craft proceeds along the descent path, commencing at the predetermined range from the termination point, means for selecting as a reference signal from the desired velocity and variable reference velocity signals the signal which is instantaneously representative of lower velocity, means for providing a signal representative of the actual velocity of the craft, and means responsive to the actual velocity and selected instantaneous velocity signals for producing an output indicative of craft attitude required to reduce the actual velocity to the predetermined lower velocity substantially at said termination point.

Claim 11

The apparatus of claim 8 including means for providing a signal representative of the craft pitch attitude and means for combining said signal representative of the craft pitch attitude with the actual velocity and selected instantaneous reference velocity signals.

Claim 12

The apparatus of claim 9 including means for providing a signal indicative of craft displacement from a glide slope beam representative of the desired descent path of the craft, and means responsive to the glide slope displacement signal for producing an output representative of vertical motion required to maintain the craft on the glide slope beam.

Claim 13

The apparatus of claim 8 wherein the variable reference velocity signal is varied as a linear function of time to produce a constant deceleration of the craft.

Claim 14

The apparatus of claim 11 including means for providing a signal representative of the craft pitch attitude to be combined with the actual velocity and selected instantaneous reference velocity signals, means for providing a signal indicative of craft displacement from a glide slope beam representative of the desired descent path of the craft, and means responsive to the glide slope displacement signal for producing an output representative of vertical motion required to maintain the craft on the glide slope beam.

Claim 15

The apparatus of claim 8 including means for continuously measuring the range to the termination point to provide the variable reference velocity signal as a linear function of range.

Claim 16

The apparatus of claim 13 including means for providing a signal representative of the craft pitch attitude to be combined with the actual velocity and selected instantaneous reference velocity signals, means for providing a signal indicative of craft displacement from a glide slope beam representative of the desired descent path of the craft, and means respoNsive to the glide slope displacement signal for producing an output representative of vertical motion required to maintain the craft on the glide slope beam.

Claim 17

The apparatus of claim 8 wherein the variable reference velocity signal is varied as a non-linear function of time such that the craft velocity decreases linearly with decreasing range to the termination point.

Claim 18

The apparatus of claim 15 including means for providing a signal representative of the craft pitch attitude to be combined with the actual velocity and selected instantaneous reference velocity signals, means for providing a signal indicative of craft displacement from a glide slope beam representative of the desired descent path of the craft, and means responsive to the glide slope displacement signal for producing an output representative of vertical motion required to maintain the craft on the glide slope beam.

Claim 19

The apparatus of claim 8 wherein the means for providing a signal representative of a desired velocity signal includes means for varying said signal as a linear function of time as the craft proceeds down the descent path from the predetermined range to a prescribed range point at which the desired velocity signal is thereafter varied as a non-linear function of time so as to cause the craft velocity to decrease linearly to the termination point.

Claim 20

The apparatus of claim 17 including means for providing a signal representative of the craft pitch attitude to be combined with the actual velocity and selected instantaneous reference velocity signals, means for providing a signal indicative of craft displacement from a glide slope beam representative of the desired descent path of the craft, and means responsive to the glide slope displacement signal for producing an output representative of vertical motion required to maintain the craft on the glide slope beam.

Claim 21

The apparatus of claim 8 including means for providing a measure of range to the termination point to vary the variable reference velocity signal as a function of square root of range from the predetermined range to a prescribed range point at which the variable reference velocity signal is thereafter varied as a linear function of range to the termination point.