Patent ID: 8606440

Claim:
A method for determining direction to a target position during steering of a point on an object towed by a towing device, the object being provided with a bird ( 10 ), said method employs feedback-free control in determining the direction and comprises the following steps: determining a first target position from a set of target positions ( 1 , 2 , 4 ); determining by means of GPS combined with compass and triangular, trilateral, or triangular and trilateral acoustic measurements a position of a first object point ( 6 ); determining velocity and acceleration of the object point ( 6 ); determining a distance vector ( 16 ) between the first object point ( 6 ) and the first target position ( 1 , 2 , 4 ); calculating the time taken before the first object point ( 6 ) is at the first target position ( 1 , 2 , 4 ); calculating a necessary acceleration of the first object point ( 6 ) in at least the lateral direction ( 14 ) or the vertical direction for the first object point ( 6 ) to hit the first target position ( 1 , 2 , 4 ) at the calculated point in time; transferring the necessary acceleration value to a steering system for the corresponding bird ( 10 ); at a later point in time and before the first target position ( 1 , 2 , 4 ) is passed by the first object point ( 6 ), determining a second target position from a set of target positions ( 1 ′, 2 ′, 4 ′) located beyond the first target position ( 1 , 2 , 4 ); determining a position of a second object point ( 6 ′); determining velocity and acceleration of the second object point ( 6 ′); determining a distance vector ( 16 ′) between the position of the second object point ( 6 ′) and the second target position ( 1 ′, 2 ′, 4 ′); calculating the time taken before the second object point ( 6 ′) is at the second target position ( 1 ′, 2 ′, 4 ′); calculating a necessary acceleration of the second object point ( 6 ′) in at least the lateral direction ( 14 ′) or the vertical direction for the second object point ( 6 ′) to hit the second target position ( 1 ′, 2 ′, 4 ′) at the calculated point in time; and transferring the necessary acceleration value to the steering system for the corresponding bird ( 10 ); wherein the steering system directs each object point ( 6 , 6 ′) toward its respective target position ( 1 , 2 , 4 ; 1 ′, 2 ′, 4 ′) independent of the other object point ( 6 ′, 6 ) and its respective current position and target position ( 1 ′, 2 ′, 4 ′; 1 , 2 , 4 ) and each object point ( 6 , 6 ′) is continually being directed toward a respective next target position.