Thrust and flight path control decoupling system

Claim 2

In combination an autothrottle control system for an aircraft having a first input coupled to first means for providing a signal representative of longitudinal acceleration information of said aircraft, and a second input coupled to second means for providing a signal representative of air speed error of said aircraft; signal processing means responsive to signals representative of pitch attitude and angle of attack information of said aircraft for providing a first compensation signal representative of longitudinal acceleration of said aircraft induced by short term flight path aNgle changes and a second compensation signal representative of the deviation of air speed due to short term flight path angle changes; third means for combining said first compensation signal with said signal representative of longitudinal acceleration information of said aircraft; and fourth means for combining said second compensation signal with said signal representative of air speed error of said aircraft.

Claim 3

The invention according to claim 1 wherein said third and fourth means comprise summing amplifiers.

Claim 4

In combination; an aircraft autothrottle having first and second input terminals for receiving signals representative of longitudinal acceleration and air speed error; pitch attitude sensing means for providing a first signal representative of pitch attitude of the aircraft; angle of attack sensing means for providing a second signal representative of angle of attack of the aircraft; first summing amplifier means for combining said first and second signals and providing a third signal; first washout circuit means responsive to said third signal for providing a first compensation signal; attitude compensated longitudinal accelerometer means for providing a fourth signal representative of longitudinal acceleration; second summing amplifier means responsive to said fourth signal and said first compensation signal for providing a signal representative of compensated longitudinal acceleration; first coupling means for coupling said signal representative of compensated longitudinal acceleration to said first input terminal; air speed error sensing means coupled to demodulator circuit means for providing a signal representative of air speed error of the aircraft; pseudo integrator circiut means responsive to said first compensation signal for providing a second compensation signal; third summing amplifier means responsive to said second compensation signal and said signal representative of air speed error for providing a signal representative of compensated air speed error; and, second coupling means for coupling said signal representative of compensated air speed error to said second input terminal.

Claim 5

In combination; an aircraft autothrottle having first and second input terminals for receiving signals representative of longitudinal acceleration and air speed error; pitch attitude sensing means for providing a first signal representative of pitch attitude of the aircraft; angle of attack sensing means for providing a second signal representative of angle of attack of the aircraft; first summing amplifier means for combining said first and second signals and providing a third signal; first washout circuit means responsive to said third signal for providing a first compensation signal; attitude compensated longitudinal accelerometer means for providing a fourth signal representative of longitudinal acceleration; second summing amplifier means responsive to said fourth signal and said first compensation signal for providing a signal representative of compensated longitudinal acceleration; first coupling means for coupling said signal representative of compensated longitudinal acceleration to said first input terminal; air speed error sensing means coupled to demodulator circuit means for providing a signal representative of air speed error of the aircraft; pseudo integrator circiut means responsive to said first compensation signal for providing a second compensation signal; third summing amplifier means responsive to said second compensation signal and said signal representative of air speed error for providing a signal representative of compensated air speed error; and, second coupling means for coupling said signal representative of compensated air speed error to said second input terminal.

Claim 6

In an autothrottle control system, an improvement for inhibiting autothrottle response to speed perturbations induced by flight path deviations comprising: first means for generating a first compensation signal in accordance with the expression

Claim 7

In an autothrottle control system, an improvement for inhibiting autothrottle response to speed perturbations induced by flight path deviations comprising: first means for generating a first compensation signal in accordance with the expression

Claim 8

In an aircraft authrottle control system having a first autothrottle input signal representative of longitudinal acceleration and a second input signal representative of air speed error: first means for generating a third signal representative of change in flight path angle; second means for generating a fourth signal representative of change in drag with respect to change in angle of attack multiplied by the product of dynamic pressure times wing area divided by the weight of the aircraft; third means for summing said thirD and fourth signals thereby providing a fifth signal; a washout circuit; fourth means for multiplying said fifth signal by the gravity acceleration constant and coupling the product to said washout circuit to provide a first compensation signal; fifth means responsive to said first compensation signal for providing pseudo integration of said first compensation signal to provide a second compensation signal; sixth means for summing said first compensation signal with said first autothrottle input signal to provide a compensated first autothrottle input signal; and seventh means for summing said second compensation signal with said second autothrottle input signal to provide a compensated second autothrottle input signal.

Claim 9

In an aircraft authrottle control system having a first autothrottle input signal representative of longitudinal acceleration and a second input signal representative of air speed error: first means for generating a third signal representative of change in flight path angle; second means for generating a fourth signal representative of change in drag with respect to change in angle of attack multiplied by the product of dynamic pressure times wing area divided by the weight of the aircraft; third means for summing said thirD and fourth signals thereby providing a fifth signal; a washout circuit; fourth means for multiplying said fifth signal by the gravity acceleration constant and coupling the product to said washout circuit to provide a first compensation signal; fifth means responsive to said first compensation signal for providing pseudo integration of said first compensation signal to provide a second compensation signal; sixth means for summing said first compensation signal with said first autothrottle input signal to provide a compensated first autothrottle input signal; and seventh means for summing said second compensation signal with said second autothrottle input signal to provide a compensated second autothrottle input signal.

Claim 10

In an autothrottle for an aircraft having first and second autothrottle input signals representative of longitudinal acceleration and air speed error, means for compensating said first and second autothrottle input signals comprising: first summing circuit means having a plurality of input terminals and an output terminal; throttle servo-tachometer means, circuit means representative of engine transfer function of the aircraft, and pseudo integrator circuit means connected in series circuit with a first of said plurality of input terminals; second circuit means for coupling said first signal representative of longitudinal acceleration to a second of said plurality of input terminals; washout circuit means coupled to said output terminal for providing a first compensating signal; third circuit means for combining said first autothrottle input signal representative of longitudinal acceleration with said first compensating signal to provide a compensated first autothrottle input signal; further pseudo integrator circuit means responsive to said first compensating signal for providing a second compensating signal; and fourth circuit means for combining said second input signal representative of air speed error with said second compensating signal to provide a compensated second autothrottle input signal.

Claim 11

In an autothrottle for an aircraft having first and second autothrottle input signals representative of longitudinal acceleration and air speed error, means for compensating said first and second autothrottle input signals comprising: first summing circuit means having a plurality of input terminals and an output terminal; throttle servo-tachometer means, circuit means representative of engine transfer function of the aircraft, and pseudo integrator circuit means connected in series circuit with a first of said plurality of input terminals; second circuit means for coupling said first signal representative of longitudinal acceleration to a second of said plurality of input terminals; washout circuit means coupled to said output terminal for providing a first compensating signal; third circuit means for combining said first autothrottle input signal representative of longitudinal acceleration with said first compensating signal to provide a compensated first autothrottle input signal; further pseudo integrator circuit means responsive to said first compensating signal for providing a second compensating signal; and fourth circuit means for combining said second input signal representative of air speed error with said second compensating signal to provide a compensated second autothrottle input signal.

Claim 12

The invention of claim 6 wherein the time constant of said washout circuit means and the further time constant of said further pseudo integrator circuit means vary as a function of the sum of air speed and forward acceleration of said aircraft.

Claim 13

The invention of claim 6 wherein said washout circuit means and said further pseudo integrator circuit means comprise respectively first and second variable time constant filtering means.

Claim 14

The invention according to claim 8 further including time constant programming means responsive to increasing air speed errors and forward accelerations of said aircraft for decreasing the respective time constants of said first and second variable time constant filtering means.

Claim 15

The invention according to claim 8 further including time constant programming means for multiplying the respective loop gains of said first and second variable time constant filtering means.

Claim 16

The invention according to claim 10 wherein said time constant programming means comprises: first amplifier means responsive to air speed error for providing an amplified air speed error signal; second amplifier means responsive to forward acceleration for providing an amplified forward acceleration signal; a positive bias signal source; and means for providing the absolute sum of said amplified error signal and said forward acceleration signal and adding to said sum said positive bias signal to provide a programming control signal for multiplying said respective loop gains of said first and second variable time constant filtering means.

Claim 17

The invention according to claim 11 wherein the gain factor of said first amplifier means is 0.4 per knot air speed error and the gain factor of said second amplifier means is 5 per knot per second acceleration.

Claim 18

In an aircraft autothrottle control system: first circuit means for providing a firSt signal representative of rate of change in throttle position; second circuit means representative of engine transfer function of said aircraft responsive to said first signal for providing a second signal representative of rate of change of thrust; pseudo integrator circuit means responsive to said second signal for providing a third signal representative of short term acceleration of said aircraft due to thrust; third circuit means for providing a fourth signal representative of longitudinal acceleration of said aircraft; fourth circuit means comprising a summing amplifier circuit responsive to said third and fourth signals for providing a fifth signal representative of acceleration of said aircraft due to deviation from the flight path; fifth circuit means comprising a washout circuit responsive to said fifth signal for providing a compensation signal; sixth circuit means comprising a summing amplifier responsive to said fifth signal and said compensation signal for providing a signal representative of compensated longitudinal acceleration for coupling to autothrottle for utilization as a thrust control damping signal; seventh circuit means comprising a pseudo integrator circuit responsive to said compensation signal for providing a further compensation signal representative of air speed error due to deviation from flight path; eighth circuit means for providing a sixth signal representative of air speed error; and ninth circuit means comprising a summing amplifier responsive to said sixth signal and said further compensation signal for providing a signal representative of compensated air speed error for coupling to autothrottle for utilization as a thrust control reference signal.

Claim 19

In an aircraft autothrottle control system: first circuit means for providing a firSt signal representative of rate of change in throttle position; second circuit means representative of engine transfer function of said aircraft responsive to said first signal for providing a second signal representative of rate of change of thrust; pseudo integrator circuit means responsive to said second signal for providing a third signal representative of short term acceleration of said aircraft due to thrust; third circuit means for providing a fourth signal representative of longitudinal acceleration of said aircraft; fourth circuit means comprising a summing amplifier circuit responsive to said third and fourth signals for providing a fifth signal representative of acceleration of said aircraft due to deviation from the flight path; fifth circuit means comprising a washout circuit responsive to said fifth signal for providing a compensation signal; sixth circuit means comprising a summing amplifier responsive to said fifth signal and said compensation signal for providing a signal representative of compensated longitudinal acceleration for coupling to autothrottle for utilization as a thrust control damping signal; seventh circuit means comprising a pseudo integrator circuit responsive to said compensation signal for providing a further compensation signal representative of air speed error due to deviation from flight path; eighth circuit means for providing a sixth signal representative of air speed error; and ninth circuit means comprising a summing amplifier responsive to said sixth signal and said further compensation signal for providing a signal representative of compensated air speed error for coupling to autothrottle for utilization as a thrust control reference signal.

Claim 20

In an autothrottle control system having first and second input signals representative of compensated longitudinal acceleration and compensated air speed error coupled as input signals to an autothrottle; compensating means comprising: first means including circuit means representative of engine transfer function for providing a third signal representative of change in thrust; second means for providing a fourth signal representative of pitch attitude compensated longitudinal acceleration; third means for providing a fifth signal representative of air speed error; fourth means comprising summing amplifier means responsive to said third and fourth signals for providing a sixth signal; fifth means comprising washout circuit means responsive to said sixth signal for providing a first compensation signal; sixth means comprising summing amplifier means for combining said first compensation signal with said fourth signal to provide said first input signal to the autothrottle; seventh means including pseudo integrator circuit means responsive to said first compensation signal for providing a second compensation signal; and eighth means comprising summing amplifier circuit means for combining said second compensation signal with said fifth signal for providing said second input signal to the autothrottle.

Claim 21

In an autothrottle control system having first and second input signals representative of compensated longitudinal acceleration and compensated air speed error coupled as input signals to an autothrottle; compensating means comprising: first means including circuit means representative of engine transfer function for providing a third signal representative of change in thrust; second means for providing a fourth signal representative of pitch attitude compensated longitudinal acceleration; third means for providing a fifth signal representative of air speed error; fourth means comprising summing amplifier means responsive to said third and fourth signals for providing a sixth signal; fifth means comprising washout circuit means responsive to said sixth signal for providing a first compensation signal; sixth means comprising summing amplifier means for combining said first compensation signal with said fourth signal to provide said first input signal to the autothrottle; seventh means including pseudo integrator circuit means responsive to said first compensation signal for providing a second compensation signal; and eighth means comprising summing amplifier circuit means for combining said second compensation signal with said fifth signal for providing said second input signal to the autothrottle.