Electronically piloted low pitch stop protection

A method of controlling and protecting a blade pitch for a propeller comprising:

• providing an actuator that is configured to be connectable to said propeller, such that displacement of said actuator corresponds to a change in blade pitch of said propeller;
• providing an electronic unit,
• providing a position control sensor to said actuator, said position control sensor being configured to interact with said actuator, to detect actuator position and thereby said blade pitch of said propeller, and said position control sensor sending a control feedback signal to said electronic unit via a first channel, based on said blade pitch, and
• providing a protection sensor to said actuator, configured to interact with said actuator and to detect actuator position and thereby said blade pitch of said propellor, and said protection sensor sending a protection feedback signal to said electronic unit via a second channel, based on said blade pitch,
• said electronic unit controlling through a control command, based on said control feedback signal, movement of said actuator to alter said blade pitch, and
• said electronic unit controlling through a protection command, based on said protection feedback signal, movement of said actuator such that said blade pitch control command is overridden when said protection feedback signal indicates that the blade pitch has reached a predefined value;
• providing a protection valve, in fluid communication with the actuator, wherein activation of the protection valve is configured to result in the actuation of blades of the propeller towards a coarse pitch,
• wherein transmission via the first channel of the controller occurs to control propeller pitch in operation of the propeller below an overspeed threshold and via the second channel, which is segregated from the first channel, to activate the protection valve in operation of the propeller above the overspeed threshold.

A blade pitch control and protection system for a propeller comprising:

• an actuator configured to be connectable to a propeller, such that displacement of said actuator corresponds to a change in blade pitch of said propeller;
• an electronic unit;
• a position control sensor configured to interact with said actuator, to detect actuator position and thereby said blade pitch of said propeller, and to send a control feedback signal to said electronic unit via a first channel, based on said blade pitch;
• and
• a protection sensor configured to interact with said actuator to detect actuator position and thereby said blade pitch of said propeller, and to send a protection feedback signal to said electronic unit via a second channel, based on said blade pitch,
• wherein said electronic unit is configured to, based on said control feedback signal received from the position sensor on the first channel, control movement of said actuator through a control command to alter said blade pitch, and
• wherein said electronic unit is further configured to, based on said protection feedback signal received from the protection sensor on the second channel, control movement of said actuator through a protection command such that said blade pitch control command is overridden when said protection feedback signal indicates that the blade pitch has reached a predefined value,
• wherein the actuator comprises a transfer tube, wherein each of the control and protection sensors is connected to the transfer tube;
• and
• wherein each of the control and protection sensors are connected to the transfer tube through dedicated redundant mechanical kinematics.