Actuation system, helicopter using the same, and controlling method therefor

A helicopter comprising:

• a rotor wing comprising blades and configured to generate propulsion by rotating said blades;
• and
• actuation systems configured to drive the blades, respectively,
• wherein each of the actuation systems comprises:
• a pump assembly including a pump chamber;
• an actuator having first and second chambers and a movable member connected to said blade and configured to convert pressures applied to said first and second chambers into a movement of said movable member;
• a valve section;
• and
• a controller configured to control said valve section to:
• (i) open a first flow path between said pump chamber and said first chamber and close a second flow path between said pump chamber with said second chamber, during a discharge period during which said pump chamber is pressurized, in a first mode,
• (ii) close said first flow path and open said second flow path during an intake period during which said pump chamber is depressurized, in the first mode;
• (iii) close said first flow path and open said second flow path during the discharge period in a second mode;
• (iv) open said first flow path and close said second flow path during the intake period in the second mode,
• wherein said valve section has a plurality of positions set by said controller, and
• wherein the plurality of plurality of positions includes:
• (i) a first position in which said valve section opens said first flow path and closes said second flow path;
• (ii) a second position in which said valve section closes said first flow path and opens said second flow path;
• and
• (iii) a neutral position in which said valve section closes said first and second flow paths is.

A pump comprising:

• a pump assembly including a pump chamber;
• a valve section;
• and
• a controller configured to control said valve section to
• (i) open a first flow path connected with said pump chamber and close a second flow path connected said pump chamber, during a discharge period during which said pump chamber is pressurized, in a first mode;
• (ii) close said first flow path and open said second flow path during an intake period during which said pump chamber is depressurized, in the first mode;
• (iii) close said first flow path and open said second flow path during the discharge period in a second mode;
• and
• (iv) open said first flow path and close said second flow path during the intake period in the second mode,
• wherein said valve section has a plurality of positions set by said controller, and
• wherein the plurality of plurality of positions includes:
• (i) a first position in which said valve section opens said first flow path and closes said second flow path;
• (ii) a second position in which said valve section closes said first flow path and opens said second flow path;
• and
• (iii) a neutral position in which said valve section closes said first and second flow paths.

A control method of an actuation system, the method comprising:

• providing an actuation system comprising a pump assembly including a pump chamber, an actuator having first and second chambers and a movable member and configured to convert pressures applied to said first and second chambers into a movement of said movable member, and a valve section;
• setting a first mode in which said valve section is controlled to open a first flow path between said pump and said first chamber and close a second flow path between said pump and said second chamber, during a discharge period during which said pump chamber is pressurized, and to close said first flow path and open said second flow path during an intake period during which said pump chamber is depressurized;
• and
• setting a second mode in which said valve section is controlled to close said first flow path and open said second flow path during the discharge period in a second mode, and to open said first flow path and close said second flow path during the intake period;
• and
• setting a neutral position between the first mode and the second mode.