Rate based autopilot system

Claim 2

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.

Claim 3

An automatic flight control system for an aircraft as set forth in claim 1 including means for generating the command signal.

Claim 4

An automatic flight control system for an aircraft as set forth in claim 2 wherein said means for generating the command signal includes means for limiting the level of authority of the command signal as applied to said first means for combining.

Claim 5

An automatic flight control system for an aircraft as set forth in claim 1 including means responsive to the movement of the aircraft about the predetermined axis to produce the control signal.

Claim 6

An automatic flight control system for an aircraft as set forth in claim 4 wherein said means responsive to the aircraft movement includes means for filtering the control signal applied to said first means for combining.

Claim 7

An automatic flight control system for an aircraft as set forth in claim 1 including a gyro responsive to the movement of the aircraft about the roll axis to produce a roll control signal.

Claim 8

An automatic flight control system for an aircraft as set forth in claim 6 including means for generating an attitude command signal input to said first means for combining.

Claim 9

An automatic flight control system for an aircraft as set forth in claim 1 including a gyro responsive to the movement of the aircraft about the pitch axis to produce a pitch control signal.

Claim 10

An automatic flight control system for an aircraft as set forth in claim 8 including means for generating an altitude error and an altitude rate command signal.

Claim 11

An automatic flight control system for an aircraft as set forth in claim 8 including means for generating a glide slope error and glide slope rate command signal.

Claim 12

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.

Claim 13

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.

Claim 14

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.

Claim 15

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.

Claim 16

An automatic flight control system as set forth in claim 12 wherein said circuit means includes means for storing the motor velocity signal generated during the sample time interval.

Claim 17

An automatic flight control system as set forth in claim 13 wherein said first means for switching disconnects said means for storing from the servo motor during the motor drive time.

Claim 18

An automatic flight control system as set forth in claim 12 wherein said power amplifier includes a first switch actuated by a motor drive signal of a first sense to apply a voltage of a first polarity from a first voltage supply to the motor, and a second switch actuated by a motor drive signal of a second sense to apply a voltage of a second polarity from a second voltage supply to the motor.

Claim 19

An automatic flight control system for an aircraft as set forth in claim 13 wherein said means for combining the control signal and the command signal includes a summing amplifier.

Claim 20

An automatic flight control system for an aircraft as set forth in claim 16 wherein said means for combining the control/command signal and the rate signal includes a summing amplifier.

Claim 21

An automatic flight control system for an aircraft as set forth in claim 13 wherein said means responsive to the movement of the aircraft includes a gyro responsive to movement of the aircraft about the roll axis to produce a roll control signal.

Claim 22

An automatic flight control system for an aircraft as set forth in claim 13 wherein said means responsive to the movement of the aircraft includes a gyro responsive to the movement of the aircraft about the pitch axis to produce a pitch control signal.