Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
303 words
In an aircraft control system utilizing angle of attack and lift acceleration signals for control purposes, the combination of: a. means for indirectly producing an estimated angle of attack signal from measured aircraft pitch moment generating signal, including: 1. network means simulating dynamic lift characteristics of an aircraft, said network means providing an output signal proportional to the estimated change of the aircraft coefficient of lift for any variation in angle of attack, said output signal being representative of the actual dynamic lift characteristics, 2. network means to convert said estimated coefficient of lift signal an estimated aircraft lift acceleration signal which is representative of the actual lift acceleration characteristics of an aircraft, 3. means for combining the estimated lift acceleration signal with signals proportional to aircraft pitch rate, roll, sideslip angle and an angular rate of the aircraft around a pitch axis to produce a signal which represents an estimated angle of attack, b. means responsive to the estimated angle of attack signal to produce a pseudo coefficient of lift signal which is linear with angle of attack over an entire range of operational values and which is thus identical with the assumed aircraft characteristics in the region where an aircraft coefficient of lift versus angle of attack is linear but deviates from the actual aircraft dynamic lift characteristics where an aircraft rate of change of coefficient of lift decreases and goes to zero with increases in angle of attack, including a newtork having a linear output signal response characteristic over the entire range of input signals and means to apply said estimated angle of attack signal as an input to said network, c. and means to convert said pseudo coefficient of lift signal to a pseudo lift acceleration signal which is linear over an entire range of aircraft angles of attack.
Claim 2
Dependent Claim
303 words
In an aircraft control system utilizing angle of attack and lift acceleration signals for control purposes, the combination of: a. means for indirectly producing an estimated angle of attack signal from measured aircraft pitch moment generating signal, including: 1. network means simulating dynamic lift characteristics of an aircraft, said network means providing an output signal proportional to the estimated change of the aircraft coefficient of lift for any variation in angle of attack, said output signal being representative of the actual dynamic lift characteristics, 2. network means to convert said estimated coefficient of lift signal an estimated aircraft lift acceleration signal which is representative of the actual lift acceleration characteristics of an aircraft, 3. means for combining the estimated lift acceleration signal with signals proportional to aircraft pitch rate, roll, sideslip angle and an angular rate of the aircraft around a pitch axis to produce a signal which represents an estimated angle of attack, b. means responsive to the estimated angle of attack signal to produce a pseudo coefficient of lift signal which is linear with angle of attack over an entire range of operational values and which is thus identical with the assumed aircraft characteristics in the region where an aircraft coefficient of lift versus angle of attack is linear but deviates from the actual aircraft dynamic lift characteristics where an aircraft rate of change of coefficient of lift decreases and goes to zero with increases in angle of attack, including a newtork having a linear output signal response characteristic over the entire range of input signals and means to apply said estimated angle of attack signal as an input to said network, c. and means to convert said pseudo coefficient of lift signal to a pseudo lift acceleration signal which is linear over an entire range of aircraft angles of attack.
Claim 3
Dependent Claim
48 words
The system according to claim 1 wherein said signal representative of the angular rate of movement of the aircraft around the pitch axis is produced by combining the estimated aircraft lift acceleration signal with signals representing gravitational forces acting on the aircraft and the velocity of the aircraft.
Claim 4
Dependent Claim
83 words
The system according to claim 1 wherein the pseudo lift acceleration signal is compared to the measured aircraft lift acceleration signal to produce a signal representative of the difference between the actual and pseudo acceleration as an indication of the penetration of the aircraft into a region in which the coefficient of lift and lift acceleration versus angle of attack relationship results in decreasing lift acceleration with increasing angle of attack and hence an indication of an aircrafts' penetration into a stall region.