抄録
Since a fully submerged hydrofoil craft cannot keep the stable height above the water surface and the attitudes on the surface, an autopilot system to stabilize the height and the attitudes of the craft is needed.
In the present paper, an analysis method for the rolling angle and banked turn control systems of a hydrofoil test craft (displacement: 4.3 tons) with fully submerged foils is described.
The test craft has two flaps attached to the port and starboad fore foils, one flap to the after foil, and a rudder at the stern of the craft body. The roll angle of the craft is stabilized by moving the port and starboard fore foils differentially through the single of the roll angle deviation of the autopilot. On the other hand, the rudder is manually operated by a helmsman, and so, the crusing direction is not automated. However, the coordinated or banked turn control system is adopted in this autopilot.
The dynamics of the lateral motion of the test craft and the characteristics of the autopilot are first described by transfer functions, and then, the roll attitude control system and the co-ordinated turn control system are synthesized by using the root locus method.
It has been shown that the calculated results for the control system coincided well with those of the sea trials by the test craft.
