Servo control systems

Claim 2

Servo control system comprising in combination: an electric actuator motor means providing a demand signal representative of a response demanded of the actuator motor, a single rate responsive electromechanical transducer coupled directly to the actuator motor and providing a first component signal, impedance means connected to the motor and providing a second component signal proportional to the back e.m.f. of the motor, both said first and seconD signals being representative of the actual rate of motor movement in response to the demand signal, filter means passing to the respective component signals and providing a feedback signal containing a greater proportion of the component signal from the actuator motor within any frequency ranges in which mechanical resonance occurs in the system and a greater proportion of the component signal from the transducer within frequency ranges devoid of such mechanical resonance, and a source responsive to the demand signal and to the feedback signal and effective to power the actuator motor.

Claim 3

Servo control system comprising in combination: an electrical motor means providing a demand signal representative of a response demanded of the actuator motor, an electromechanical transducer coupled directly to the actuator motor and providing a first electrical signal representative of the rate of operation of the actuator motor, impedance means connected to the actuator motor and providing a second electrical signal proportional to the back e.m.f. of the motor and representative of the rate of operation of the latter a band attenuation filter passing the first signal, said filter attenuating said signal within any frequency range within which mechanical resonance occurs in the system, but transmitting said signal outside said range, a band pass filter passing the second signal, said filter transmitting said signal within any said frequency range within which mechanical resonance occurs, and attenuating said signal outside said range, means combining the first and second signals so that the filtered signals substantially compensate each other at resonance to provide a resultant feedback signal, and a source responsive to the demand signal and to the feedback signal to power the actuator motor.

Claim 4

Servo control system comprising in combination: an electrical motor means providing a demand signal representative of a response demanded of the actuator motor, an electromechanical transducer coupled directly to the actuator motor and providing a first electrical signal representative of the rate of operation of the actuator motor, impedance means connected to the actuator motor and providing a second electrical signal proportional to the back e.m.f. of the motor and representative of the rate of operation of the latter a band attenuation filter passing the first signal, said filter attenuating said signal within any frequency range within which mechanical resonance occurs in the system, but transmitting said signal outside said range, a band pass filter passing the second signal, said filter transmitting said signal within any said frequency range within which mechanical resonance occurs, and attenuating said signal outside said range, means combining the first and second signals so that the filtered signals substantially compensate each other at resonance to provide a resultant feedback signal, and a source responsive to the demand signal and to the feedback signal to power the actuator motor.

Claim 5

System as claimed in claim 1, including means combining the component signals so that they substantially complement each other at resonance whereby the resulting feedback signal is substantially free of resonance components.

Claim 6

System as claimed in claim 1 in which, within frequency ranges containing mechanical resonances, the component signals are combined with relative magnitudes which are in the ratio of the inertias of the actuator and the inertia, or referred inertia, of the transducer.

Claim 7

System as claimed in claim 1, in which the feedback signal is constituted wholly by the component signal from the tachometer generator in said frequency ranges devoid of mechanical resonance.

Claim 8

System as claimed in claim 1, in which the filter means comprise respective band pass and band attenuation filters through which the component signals from the actuator and the transducer respectively are passed, the pass and attenuation bands of the respective filters including the resonance frequencies of the system.

Claim 9

System as claimed in claim 2, in which the signal combining means are effective, within said frequency range containing mechanical resonance, to combine the two filtered signals with relative magnitudes which are in the ratio of the inertia of the actuator to the inertia, or referred inertia, of the transducer.