Landing aid system

Claim 2

A landing aid system for an aircraft having associated velocity and acceleration vectors comprising at least one first navigation device having a first output, furnishing the three coordinates, in a first system of given rectangular axes, of one of said vectors of the aircraft, at least one second navigation device, having a second output, independent of the first navigation device, furnishing the three co-ordinates Of the position of the aircraft in a second system of given rectangular axes, said landing aid system further comprising: a coordinate transformer, having a third output, for changing axes furnishing the three co-ordinates of said one vector in the second system of axes; and three identical integrating loops respectively associated with each of the axes, each loop comprising two output terminals, an input connected to said third output, a further input connected to said second output, one adding and integrating circuit having a first input connected to said input of the loop, a second input and an output and a subtractor, connected between said output of the integrating and adding circuit and said further input of the loop, and having an output, connected to the second input of the adding and integrating circuit, the latter supplying the co-ordinates, parallel to the considered axis, of the velocity and position of the aircraft, to said output terminals.

Claim 3

A system as claimed in claim 1, wherein the first navigation device furnishes the coordinates of the velocity vector, each adding and integrating circuit comprising an adder having two inputs of which one is connected to the output of the first navigation device and the other to the output of the subtractor through an amplifier and an output, and an integrator connected in series between the output of the adder and the subtracter and having an output, each loop comprising two accessible output terminals, respectively the output of the adder furnishing the considered co-ordinate of the aircraft velocity and the output of the integrator furnishing the co-ordinate of the position of the aircraft.

Claim 4

A system as claimed in claim 1, wherein the first navigation device furnishes the coordinates of the acceleration vector, said adding and integrating circuit comprising : two identical units in series, each of which comprise an adder having two inputs and an output, and an integrator having an input and an output, the adder of one of the units having two inputs coupled respectively to the first navigation device output and to the output of the subtractor, through a first amplifier and an output coupled to the input of the integrator of the same unit, the adder of the other unit, having inputs respectively coupled to the output of the integrator of the first unit and to the output of the subtractor, through a second amplifier, and an output coupled to the second integrator input, the output of said last mentioned integrator being coupled to the second input of the subtractor, and : output terminals respectively connected to the input and to the output of the second integrator and furnishing respectively the considered co-ordinate of the velocity vector and that of the aircraft.

Claim 5

A system as claimed in claim 1, wherein the output terminals of said integrating loops are connected to the aircraft piloting devices.

Claim 6

A system as claimed in claim 1, comprising a device, having an output, for indicating the azimuth angle of the runway, wherein said second system of axes comprise a horizontal axis carried by the axis of the runway, a second horizontal axis and a vertical axis, and said first system of axes also comprises a vertical axis and an axis oriented in the north direction, said co-ordinate transformer comprising an input connected to the said azimuth angle indicating device output.

Claim 7

A system as claimed in claim 1, associated with a vertical axis data generator having longitudinal attitude and lateral attitude outputs, wherein said second system of axes comprises a horizontal axis carried by the axis of the runway, a second horizontal axis and a vertical axis, and said first system of axes is fixed in the aircraft and comprises the body axis, i.e., an axis carried by the longitudinal or roll axis of the aircraft , an axis perpendicular to the preceding and horizontal in stabilized flight as concerns roll, or lateral or pitch axis, and a yaw axis, wherein said second navigation device has a cOurse output, said coordinate transformer comprising two inputs respectively connected to said longitudinal attitude and lateral attitude outputs, and a third input connected to said ''''course'''' output.

Claim 8

A system as claimed in claim 1, wherein said first and second devices are respectively constituted by a inertia unit and an Independent Landing Monitor.

Claim 9

A system as claimed in claim 1, comprising further means, having an output for determining the altitude and in which said second system of axes comprises a vertical axis, the coordinate of the aircraft, parallel to said axis, representing the altitude of the latter, said landing aid system comprising a switch for selectively connecting the second input of the integrating loop pertaining to the coordinate along the vertical axis to the output of the second navigation device when one of the altitude and distance parameters is greater than a given value and to the output of said further means when said parameter is smaller than said given value.

Claim 10

A system as claimed in claim 1, wherein the adding and integrating circuit of each loop comprises an adder having two inputs and an output, and an integrator connected in series between the output of the adder and the output of the adding and integrating circuit, the output of the adder furnishing the considered coordinate of the aircraft velocity and the output of the integrator furnishing the coordinate of the position of the aircraft, said outputs being connected respectively to the output terminals of the loop.

Claim 11

A landing aid system comprising at least one first navigation device having a first output, furnishing the three coordinates, in a first system of given rectangular axes, of the acceleration vector of the aircraft, at least one second navigation device, having a second output, independent of the first navigation device, furnishing the three coordinates of the position of the aircraft in a second system of given rectangular axes, said landing aid system further comprising: a coordinate transformer, having a third output, for changing axes, furnishing the three coordinates of the acceleration vector in the second system of axes; and three identical integrating loops respectively associated with each of the axes, each loop comprising two output terminals, an input connected to said third output, a further input connected to said second output, a first adding and integrating circuit having a first input connected to said input of the loop, a second input and an output, a second adding and integrating circuit having a first input connected to the output of said first adding and integrating circuit, a second input and an output, and a subtractor connected between said output of the second adding and integrating circuit and said further input of the loop, and having an output, connected to the said second input of the two adding and integrating circuits, the second adding and integrating circuit supplying the coordinates, relative to the considered axis, of the velocity and position of the aircraft to said output terminals of the loop.

Claim 12

A landing aid system comprising at least one first navigation device having a first output, furnishing the three coordinates, in a first system of given rectangular axes, of the acceleration vector of the aircraft, at least one second navigation device, having a second output, independent of the first navigation device, furnishing the three coordinates of the position of the aircraft in a second system of given rectangular axes, said landing aid system further comprising: a coordinate transformer, having a third output, for changing axes, furnishing the three coordinates of the acceleration vector in the second system of axes; and three identical integrating loops respectively associated with each of the axes, each loop comprising two output terminals, an input connected to said third output, a further input connected to said second output, a first adding and integrating circuit having a first input connected to said input of the loop, a second input and an output, a second adding and integrating circuit having a first input connected to the output of said first adding and integrating circuit, a second input and an output, and a subtractor connected between said output of the second adding and integrating circuit and said further input of the loop, and having an output, connected to the said second input of the two adding and integrating circuits, the second adding and integrating circuit supplying the coordinates, relative to the considered axis, of the velocity and position of the aircraft to said output terminals of the loop.

Claim 13

A system as claimed in claim 10, wherein each adding and integrating circuit of each loop comprises an adder having two inputs and an output, and an integrator connected in series between the output of the adder and the output of the adding and integrating circuit, and wherein the output of the adder and the output of the integrator of the second adding and integrating circuit, furnishing respectively the considered coordinates of the aircraft velocity and position, are connected respectively to the output terminals of said loop.

Claim 14

A system as claimed in claim 10, wherein the output terminals of said integrating loops are connected to the aircraft piloting devices.

Claim 15

A system as claimed in claim 10, comprising further means, having an output for determining the altitude and in which said second system of axes comprises a vertical axis, the coordinate of the aircraft, parallel to said axis, representing the altitude of the latter, said landing aid system comprising a switch for selectively connecting the second input of the integrating loop pertaining to the coordinate along the vertical axis to the output of the second navigation device when one of the altitude and distance parameters is greater than a given value and to the output of said further means when said parameter is smaller than said given value.

Claim 16

A system as claimed in claim 10, comprising a device, having an output, for indicating the azimuth angle of the runway, wherein said second system of axes comprise a horizontal axis carried by the axis of the runway, a second horizontal axis and a vertical axis, and said first system of axes also comprises a vertical axis and an axis oriented in the north direction, said co-ordinate transformer comprising an input connected to said azimuth angle indicating device output.

Claim 17

A system as claimed in claim 10, associated with a vertical axis data generator having longitudinal attitude and lateral attitude outputs, wherein said second system of axes comprises a horizontal axis carried by the axis of the runway, a second horizontal axis and a vertical axis, and said first system of axes is fixed in the aircraft and comprises the body axis, i.e. an axis carried by the longitudinal or roll axis of the aircraft, an axis perpendicular to the preceding and horizontal in stabilized flight as concerns roll, or lateral or pitch axis, and a yaw axis, wherein said second navigation device has a course output, said coordinate transformer comprising two inputs respectively connected to said longitudinal attitude and lateral attitude outputs, and a third input connected to said course output.

Claim 18

A system as claimed in claim 10, wherein said first and second devices are respectively constituted by an inertia unit and an Independent Landing Monitor.