Abstract
This paper analyzes the stability of pleasure boats controlled by human in order to develop an electronic control steering system of those boats. At first, the equation of motion for pleasure boats in the global coordinate is derived. This equation of motion is used to compute a man-machine system model for controlled pleasure boats. As the first case, the stability of pleasure boats controlled by human proportional action is analyzed based on the man-machine system model. The stability region can be reduced when the distance to forward gazing point is long, and can be enlarged when the velocity of pleasure boat is high. As the second case, the stability of pleasure boats controlled by proportional action added derivative action is analyzed. Compared with the first case, the stability region expands when the distance to forward gazing point is short. As the third case, the stability of pleasure boats controlled by proportional action added time delay is analyzed. Compared with the first case, the stability region expands when the distance to forward gazing point is long. As the fourth case, the stability of pleasure boats controlled by proportional action added integral action is analyzed. Compared with the first case, the stability region expands when the distance to forward gazing point is short. From those analysis, it can be seen that the time delay can be expected to improvement the stability of pleasure boats since it is appropriate for implementation of the control algorithm.
