GB1381436A - Control system for hydrofoil craft - Google Patents

Abstract

1381436 Hydrofoil craft; stabilizing BOEING CO 10 April 1973 [31 Oct 1972] 17204/73 Headings B7A and B7M A hydrofoil craft is caused to begin to bank automatically about its roll axis 60 before turning about its yaw axis 64 in response to the helm. The craft has forward and aft foils 16, 26, at least one having separate port and starboard flaps, e.g. 28, 30, 32, 34, and means for generating a command signal for turning the craft. Further means respond to the command signal to actuate the separate flaps 28-34 to cause the craft to bank in the direction of the desired turn. This banking is then sensed by means to which is coupled apparatus for actuating the rudder. As shown in Fig. 5, the craft is equipped with various sensors (left hand side) which are located as indicated in Fig. 2 which is a view from below the craft. When it is desired to turn the craft about its yaw axis 64 a turn signal from helm 72 is fed via line 70 to an amplifier 80 which compares the turn signal with the roll signal from the vertical gyro 44 and produces an output dependent on their difference to operate flaps 28-34 which cause the craft to roll. The roll continues until the roll signal from gyro 44 is large enough to null the signal from helm 72. At the same time, the signal on line 82, proportional to the roll angle, is applied to the rudder servo 92 to operate the (forward) rudder 12. Signals from the yaw rate gyro 45 and the lateral accelerometer 38 are also applied to rudder servo 92 to limit its effect. Stabilization.-Forward flap 18 is actuated to counteract pitching, by a signal which is combined, in amplifier 100, from a signal from the forward accelerometer 35 and a signal from circuit 98 proportional to the roll signal squared. (This is because rolling produces a vertical acceleration component.) In addition, pitching is counteracted by the operation of all the flaps by signals from the vertical gyro 44. Roll is counteracted by the roll signal from gyro 44 being fed alternately to the port and starboard servos 84, 86 and 88, 90. Heave is counteracted by signals from port and starboard vertical accelerometers 42, 40 being applied to port and starboard flap servos 84, 86, and 88, 90, respectively. Craft construction.-Forward foil 16 and rudder 12 are pivotable in a forward and upward direction to a position suitable for hull-borne operation. Similarly the aft foil 26 is mounted between two legs 20, 22 which are pivotable about 21 upwardly and to the rear. Propulsion.-The vessel may be provided with a screw propeller for hull-borne propulsion and a separate screw propeller or water-jet installation for foil-borne propulsion.