Force control improvement through combined stroke feedforward and stroke feedback compensation
AssigneeThe Boeing Company
InventorsAlessandro Vieira, Gerard V. Bohr
Life of this patent
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Abstract
Control compensation methods and configurations for controlling actuators that are applying forces to a test article. The control compensation methods and configurations reduce force control tracking errors by the use of combined stroke feedforward and stroke feedback signals. These counteract errors caused by multi-actuator cross coupling and other challenging behaviors caused by various issues with the actuators.
Claims20
A control system configured to control a plurality of actuators to perform fatigue cycles on a test article, comprising, for each actuator:
- a function generator configured to output, for each load case pair, a stroke command signal specifying a target position of the actuator and a force command signal specifying a target force applied by the actuator;
- a stroke control loop comprising:
- a feedforward path configured to differentiate and factor the stroke command signal;
- a feedback path configured to adjust the stroke command signal by a stroke feedback signal;
- and
- a stroke summing junction configured to combine the feedforward path and the feedback path;
- a force control loop comprising:
- a feedback path configured to adjust the force command signal by a force feedback signal;
- proportional and integral compensators;
- and
- a force summing junction configured to combine outputs from the proportional and integral compensators and the stroke control loop in an actuator control signal;
- and
- control circuits configured to control the actuator in response to the actuator control signal.
A method of controlling a plurality of actuators to perform fatigue cycles on a test article, comprising, for each actuator and iteratively for each load case:
- retrieving a stroke command signal to control the actuator;
- retrieving a force command signal to control the actuator;
- generating a stroke control signal in response to the stroke command signal and a stroke feedback signal of a current position of the actuator;
- generating a force control signal in response to the force command signal and a force feedback signal of a current force applied by the actuator;
- combining the stroke control signal and the force control signal to drive the actuator;
- and
- wherein, upon each new load case, generating the stroke control signal additionally in response to a feedforward signal generated from the stroke command signal.
A non-transitory computer-readable medium storing instructions executable by a processor to control an actuator to perform operations to conduct fatigue cycles on a test article, the operations comprising:
- retrieving a stroke command signal specifying a target position of the actuator;
- retrieving a force command signal specifying a target force applied by the actuator;
- generating a stroke control signal in response to the stroke command signal and feedback from sensing a current position and changes in position of the actuator;
- generating a force control signal in response to the force command signal and feedback from sensing a current force applied by the actuator;
- and
- combining the stroke control signal and the force control signal to drive the actuator to the target position and to apply the target force.
Dependencies are inferred from the claim text.