1. Field of the Invention
The present invention relates to a landing-control device and method for an aircraft, and particularly to control of a vertical speed of landing on a place where a landing surface such as a ship deck that swings with time.
2. Description of the Related Art
There have been hitherto proposed various control technologies that use a neural network as one of technologies controlling a control target with high precision irrespective of a non-linear element of the control target, external disturbance or a change of an environment over time. According to the neural network, a coupling weight coefficient is properly set in a learning process carried out in advance, so that a required control parameter can be output-based on predetermined input information with high precision. A back propagation method is generally used in the learning process of the neural network. Control using the neural network includes air-fuel ratio control of an internal-combustion engine disclosed in the JP-A-9-88685, or control of a robot, a machine tool, an XY stage, a disc device or the like disclosed in the JP-A-7-36506.
Vertical takeoff and landing aircrafts such as helicopters, etc. are utilized on many occasions because they do not need a long runway at the takeoff and landing and do not limit a landing place, and thus automation of the control thereof has been desired.
However, with respect to this type of aircrafts, the merit that no limitation is imposed on any landing place rather makes it difficult to perform automation of control. For example, in the case of landing on a landing surface such as a ship deck, the landing surface swings due to a wave surface, and thus the speed control of the aircraft in the vertical direction is more difficult than in the case of landing on a static landing surface. This is because if the speed control fails, an impact of the landing is intensified (a hard landing state), resulting in damage of the body of the aircraft. Furthermore, since the wave surface is irregular, it is difficult for a conventional control technology to estimate the wave surface for the control, and thus there is no other way to rely on than a manual operation of an experienced operator.