US 4,378,518 AGranted

Rate based autopilot system

AssigneeEdo-Aire Mitchell

InventorJohn M. Nixon

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Abstract

An automatic flight control system for an aircraft having a control surface 28 and including a gyro 12 having an output applied through an attitude filter 14 to the input of a roll rate circuit 16 and a summing amplifier 18. The roll rate circuit 16 generates a rate signal that is applied to a summing amplifier 20 generating a roll rate control signal. The roll rate control signal is input to a roll servo amplifier 22. The servo amplifier 22 combines the rate control signal with a motor velocity signal from a motor velocity detector as part of a roll servomotor 26. Mechanically interconnected to the roll servomotor 26 is the control surface 28 for maneuvering an aircraft about its roll axis. Also, input to the summing amplifier 18 are aircraft command signals from a command block 10 where the authority of such signals is set by a limiter 30. The output of the summing amplifier 18 is applied to a second input of the summing amplifier 20 which generates the rate control signal from a combination of the two input signals applied thereto. For the pitch axis of the aircraft, similar circuitry is interconnected to drive a pitch servomotor 46 that is mechanically interconnected to a control surface 48.

Claims19

Dependent claims

An automatic flight control system responsive to a control signal that varies with movement of an aircraft about a predetermined axis, the aircraft having a control surface coupled to a servo motor and movable with respect to the aircraft fuselage to cause movement thereof about a predetermined axis, comprising:

rate circuit means connected to receive the control signal and generating a derived rate output voltage varying with the control signal;
first means responsive to the control signal and an aircraft command signal for combining into a control/command signal;
second means responsive to the control/command signal and to the output voltage of said rate circuit means for combining into a motor vehicle command;
circuit means connected to the servo motor and responsive to the motor velocity during a motor simple time for generating a motor velocity signal, said circuit means including first means for switching from a first position during a motor drive time to a second position during the motor sample time in response to a sample time interval signal;
means responsive to the motor velocity signal and the motor velocity command to generate a motor drive signal to command the velocity of said servo motor;
a power amplifier activated during the motor drive time and responsive to the generated motor velocity command to apply to the motor a voltage at a level proportional to the motor velocity command, said power amplifier including second means for switching from a first position during the motor sample time to hold the amplifier input at a fixed value to a second position during the motor drive time to apply to the motor the voltage proportional to the motor velocity command and thereby command the velocity of the motor in response to a motor time signal;
and
means for generating the sample time interval signal to said first means for switching and for generating the motor time signal to said second means for switching to establish a motor drive time longer than the motor sample time.

5 more elements

An automatic flight control system for an aircraft having a control surface coupled to a servo motor and movable with respect to the aircraft fuselage to cause movement thereof about a predetermined axis, comprising:

means for generating a control signal that varies with movement of the aircraft about the predetermined axis;
means for generating a command signal;
means for combining the control signal and the command signal into a control/command signal;
rate circuit means connected to receive the control signal and generating a derived rate output voltage varying with the control signal;
means responsive to the control/command signal and the output voltage of said rate circuit means for combining into a motor velocity command;
circuit means connected to the servo motor and responsive to the motor velocity during a motor sample time for generating a motor velocity signal, said circuit means including first means for switching from a first position during a motor drive time to a second position during the motor sample time in response to a sample time interval signal;
means responsive to the motor velocity signal and the motor velocity command to generate a motor drive signal to command the velocity of said servo motor;
a power amplifier activated during the motor drive time and responsive to the generated motor drive signal to apply to the motor a voltage at a level proportional to the motor velocity command, said power amplifier including second means for switching from a first position during the motor sample time to hold the amplifier input at a fixed value to a second position during the motor drive time to apply to the motor the voltage proportional to the motor velocity command and thereby command the velocity of the motor in response to a motor time signal;
and
means for generating the sample time interval signal to said first means for switching and for generating the motor time signal to said second means for switching to establish a motor drive time longer than the motor sample time.

7 more elements

An automatic flight control system responsive to a control signal that varies with movement of an aircraft about a predetermined axis, the aircraft having a control surface movable with respect to the aircraft fuselage to cause movement thereof, comprising:

rate circuit means connected to receive the control signal and generating a derived rate output voltage varying with the control signal;
a servo motor;
circuit means connected to the servo motor and responsive to the motor velocity during a motor sample time for generating a motor velocity signal, said circuit means including first means for switching from a first position during a motor drive time to a second position during the motor sample time in response to a sample time interval signal;
means responsive to the motor velocity signal and the output voltage of said rate circuit means to generate a motor drive signal to command the velocity of said servo motor;
a power amplifier activated during the motor drive time and responsive to the generated motor drive signal to apply to the motor a voltage at a level proportional to the motor drive signal, said power amplifier including second means for switching from a first position during the motor sample time to hold the amplifier input at a fixed value to a second position during the motor drive time to apply to the motor the voltage proportional to the motor drive signal and thereby command the velocity of the motor in response to a motor time signal;
and
means for generating the sample time interval signal to said first means for switching and for generating the motor time signal to said second means for switching to establish a motor drive time longer than the motor sample time.

4 more elements

Dependencies are inferred from the claim text.