초록 ▼

A method of controlling the yaw attitude of a hybrid helicopter including a fuselage and an additional lift surface provided with first and second half-wings extending from either side of the fuselage, each half-wing being provided with a respective first or second propeller. The hybrid helicopter h

A method of controlling the yaw attitude of a hybrid helicopter including a fuselage and an additional lift surface provided with first and second half-wings extending from either side of the fuselage, each half-wing being provided with a respective first or second propeller. The hybrid helicopter has a thrust control suitable for modifying the first pitch of the first blades of the first propeller and the second pitch of the second blades of the second propeller by the same amount. The hybrid helicopter includes yaw control elements for generating an original order for modifying the yaw attitude of the hybrid helicopter by increasing the pitch of the blades of one propeller and decreasing the pitch of the blades of the other propeller, the original order is optimized as a function of the position of the thrust control to obtain an optimized yaw control order that is applied to the first and second blades.

대표청구항 ▼

1. A method of controlling the yaw attitude of a hybrid helicopter having a fuselage and comprising: a main lift rotor arranged above said fuselage;first and second propellers disposed on either side of said fuselage;a thrust control suitable for modifying a first pitch of first blades of the first

1. A method of controlling the yaw attitude of a hybrid helicopter having a fuselage and comprising: a main lift rotor arranged above said fuselage;first and second propellers disposed on either side of said fuselage;a thrust control suitable for modifying a first pitch of first blades of the first propeller and a second pitch of second blades of the second propeller by the same quantity; andyaw control means suitable for generating an original order (O1) for modifying the yaw attitude of said hybrid helicopter by increasing the pitch of said first blades and by decreasing the pitch of said second blades by a differential pitch; wherein said original order (O1) is optimized as a function of the position of the thrust control to obtain an optimized yaw control order (O2) that is applied to said first and second blades. 2. A method according to claim 1, wherein, in order to obtain said optimized order, said original order (O1) given in differential pitch degrees is corrected by adding to said original order (O1) a corrective term that is a function of the position of the thrust control in accordance with the following first relationship: O2=O1+P0*[1−(PCOM/100)] where O2 represents said optimized order, O1 represents said original order, P0 represents the differential pitch at zero thrust and when the yaw control means is centered, PCOM represents the resultant thrust percentage generated by the thrust control in percent, and “*” and “/” represent respectively the multiplication sign and the division sign. 3. A method according to claim 1, wherein in order to obtain said optimized order, said original order is modulated by a variable gain that is variable as a function of the position of the thrust control and a corrective term is added that is a function of the position of the thrust control in accordance with the following third relationship: O2=O1*G+P0*[1−(PCOM/100)] where O2 represents said optimized order, O1 represents said original order, G represents said gain, P0 represents said differential pitch at zero thrust and when the yaw control means are centered, PCOM represents the resultant thrust percentage generated by the thrust control in percent, and “*” and “/” represent respectively the multiplication sign and the division sign. 4. A method according to claim 1, wherein, in order to obtain said optimized order, said original order is modulated by a variable gain that is variable as a function of the thrust control in accordance with the following second relationship: O2=O1*G where O2 represents said optimized order, O1 represents said original order, G represents said gain, and “*” represents the multiplication sign. 5. A method according to claim 4, wherein said gain (G) decreases from a maximum gain (GMAX) applied when said thrust control generates a minimum resultant thrust from the first and second propellers towards a minimum gain (GMIN) applied when the thrust control generates a maximum resultant thrust from the first and second propellers. 6. A method according to claim 5, wherein said gain (G) is determined using the following fourth relationship in which “G” represents said gain, “GMIN” said minimum gain, “GMAX” said maximum gain, “PCOM” the resultant thrust percentage generated by the position of the thrust control at a given instant, in percentage, and “*” and “/” represent respectively the multiplication sign and the division sign: G=GMAX−[(GMAX−GMIN)*(PCOM/100)] 7. A method according to claim 5, wherein said minimum gain (GMIN) is equal to one third of said maximum gain (GMAX). 8. A method according to claim 1, wherein, in order to obtain said optimized order, said original order (O1) given in differential pitch degrees is corrected by adding to said original order (O1) a corrective term that is a function of the position of the thrust control. 9. A method according to claim 8, wherein the corrective term is based upon the differential pitch at zero thrust and when the yaw control means is centered, and the resultant thrust percentage generated by the thrust control in percent. 10. A hybrid helicopter having a fuselage and comprising: a main lift rotor arranged above said fuselage;first and second propellers disposed on either side of said fuselage;a thrust control suitable for modifying a first pitch of first blades of the first propeller and a second pitch of second blades of the second propeller by the same quantity;a yaw control device provided with yaw control means suitable for generating an original order (O1) for modifying the yaw attitude of said hybrid helicopter by increasing the pitch of said first blades and by decreasing the pitch of said second blades by a differential pitch; anda combiner suitable for combining a thrust control order and a differential pitch control order;wherein said yaw control device includes adjustment means suitable for optimizing said original order (O1) as a function of the position of the thrust control in order to obtain an optimized yaw control order (O2) for application to said first and second blades. 11. A hybrid helicopter according to claim 10, wherein said adjustment means comprise said combiner connected to the yaw control means via at least a left link and a right link, to the thrust control by a second main linkage, to a first control member for controlling the first pitch via a first secondary linkage, and to a second control member for controlling the second pitch via a second secondary linkage, said combiner comprising: a carrier structure having a first end zone hinged on a support with a second end zone hinged to said second main linkage;a first lever having a first end hinged to the left link and a second end hinged to the first secondary linkage, said first lever being free to pivot about a first fastener axis fastening it to said carrier structure;a second lever having a first end hinged to the right link and having a second end hinged to the second secondary linkage, said second lever being free to pivot about a second fastener axis fastening it to said carrier structure; anda first lever arm separating the first end of the first lever from said first fastener axis being shorter than a second lever arm separating the second end of the second lever from said second fastener axis. 12. A hybrid helicopter according to claim 10, wherein said adjustment means comprise a crank arranged in series in a first main linkage between an upstream first main linkage connected to the yaw control means and a downstream first main linkage going towards said combiner, said crank being provided with an upstream radius and a downstream radius forming an angle between them, said upstream radius being fastened to said upstream first main linkage while said downstream radius is linked to said downstream first main linkage, said crank including quotient-varying means for varying the quotients of the second length of the downstream radius divided by the first length of the upstream radius, said quotient varying means being mechanically controlled by the thrust control. 13. A hybrid helicopter according to claim 10, wherein said adjustment means include a second computer connected in particular firstly to the thrust control and to the yaw control via electrical or optical connections, and secondly to first and second control actuators for controlling respective first and second control members for controlling the first and second pitches, said second computer means optimizing said original order (O1) as a function of the position of the thrust control to obtain an optimized yaw control order (O2) that is applied to the first and second control actuators. 14. A hybrid helicopter according to claim 10, wherein said adjustment means comprise a first adjustable element of a first secondary linkage and a second adjustable element of a second secondary linkage, and first computer means of said adjustment means being suitable for modifying the lengths of said first and second adjustable elements as a function of the thrust control to modulate said original order by a variable gain that varies as a function of the position of said thrust control. 15. A hybrid helicopter according to claim 14, wherein at least one adjustable element comprises an actuator secured to an upstream secondary linkage and a downstream secondary linkage, said actuator being provided with an actuator body and an actuator rod, the yaw control means moving said upstream secondary linkage via a combiner over a first distance (DIS1) in a first travel direction, and said first computer means cause said actuator rod to be moved relative to said actuator body over a second distance (DIS2) in a second travel direction opposite to said first travel direction, said second distance (DIS2) being determined by said first computer means using the following equation: DIS2=DIS1*(1−G) where G represents said variable gain. 16. A hybrid helicopter according to claim 14, wherein said adjustment means include one position sensor per adjustable element connected to said first computer means to provide it with information relating to the length of the corresponding adjustable element. 17. A hybrid helicopter according to claim 14, wherein said adjustment means include a thrust sensor connected to said first computer means to provide it with first information relating to the position of said thrust control. 18. A hybrid helicopter according to claim 14, wherein said adjustment means include a yaw sensor connected to said first computer to provide it with second information relating to the position of said yaw control means. 19. A method of controlling the yaw attitude of a hybrid helicopter having a fuselage and comprising: a main lift rotor arranged above said fuselage;a first propeller disposed on a first side of said fuselage;a second propeller disposed on a second side of said fuselage;a thrust control suitable for modifying a first pitch of first blades of the first propeller and a second pitch of second blades of the second propeller, the first pitch being the same as the second pitch; andyaw controller suitable for generating an original order (O1) for modifying the yaw attitude of said hybrid helicopter by increasing the pitch of said first blades and by decreasing the pitch of said second blades by a differential pitch; wherein said original order (O1) is optimized as a function of the position of the thrust control to obtain an optimized yaw control order (O2) that is applied to said first and second blades. 20. A method according to claim 19, wherein, in order to obtain said optimized order, said original order (O1) given in differential pitch degrees is corrected by adding to said original order (O1) a corrective term that is a function of the position of the thrust control in accordance with the following first relationship: O2=O1+P0*[1−(PCOM/100)] where O2 represents said optimized order, O1 represents said original order, P0 represents the differential pitch at zero thrust and when the yaw control means is centered, PCOM represents the resultant thrust percentage generated by the thrust control in percent, and “*” and “/” represent respectively the multiplication sign and the division sign.