Patent ID: 11912436
Assignee: YANSHAN UNIVERSITY
Field: Control (Instruments)
Classification: CPC B  G | IPC B  G

Claim 0:
1. A method of operating a fully automated towing, alignment and hangar system suitable for an offshore operation helicopter, comprising following steps:
S1. acquiring an attitude image of a steering wheel of a helicopter, wherein as a helicopter transfer system enters an automatic control mode, the attitude image of the current steering wheel of the helicopter is acquired by a wide-angle camera;
S2. calculating a helicopter yaw angle and a steering wheel deflection angle, wherein a DSP control unit processes the acquired attitude image of the steering wheel of the helicopter, extracts characteristic information, and calculates the helicopter yaw angle and the steering wheel deflection angle of the helicopter; the characteristic information includes a contour pixel matrix of a circle, a tire and a rotating shaft of the helicopter steering wheel, and the steering wheel deflection angle are directly obtained through characteristics of the contour pixel matrix;
S3. calculating a position coordinate of the steering wheel of the helicopter, a first wheel and a second wheel in a deck coordinate system, wherein a helicopter coordinate system and the deck coordinate system are created, and the position coordinate of the steering wheel of the helicopter, the first wheel and the second wheel in the deck coordinate system are calculated through a coordinate transformation relationship and the helicopter yaw angle;
S31. creating the helicopter coordinate system, wherein the position coordinate of the steering wheel of the helicopter, the first wheel and the second wheel in the helicopter coordinate system are calculated according to size parameters of the helicopter and the helicopter yaw angle; the helicopter coordinate system takes a helicopter mooring bar as an origin, and when the helicopter yaw angle is 0°, a central axis of the helicopter is a y0 axis, a direction pointing to a bow is a positive direction of the y0 axis, a ray perpendicular to the y0 axis is an x0 axis, and a direction pointing to a starboard side of a ship is a positive direction of the x0 axis;
S32. creating a deck coordinate system, wherein the deck coordinate system takes a starting point of a deck towing track of the ship as a coordinate origin, a central axis of a starting part of the deck towing track as a y axis, a direction pointing to a bow of a ship as a positive direction of they axis, a ray perpendicular to they axis as an x axis, and a direction pointing to a starboard side of the ship as a positive direction of the x axis, and a mathematical equation of the deck towing track and a trajectory equation of a towing indication line are created under the deck coordinate system;
S33. obtaining the position coordinate of the steering wheel of the helicopter, the first wheel and the second wheel in the deck coordinate system by calculating the coordinate transformation relationship from the helicopter coordinate system to the deck coordinate system;
S4. judging boundaries of the steering wheel, the first wheel and the second wheel relative to the towing indication line, wherein the position boundaries of the steering wheel, the first wheel and the second wheel in the deck coordinate system are judged relative to the mathematical equation of the deck towing track and the trajectory equation of the towing indication line; corresponding relationship between the position coordinates of the steering wheel, the first wheel and the second wheel and the trajectory equation of the towing indication line is obtained by calculating a distance from a point to a line, and the corresponding relationship includes three scenarios, that is, inside, above and outside the towing indication line;
S5. extracting an optimal movement path suitable for the helicopter, wherein the optimal movement path suitable for the helicopter at a current attitude is extracted from a knowledge base according to boundary judgment results of the steering wheel, the first wheel and the second wheel and the steering wheel deflection angle; and the knowledge base consists of a large number of manual operation practices, and is compiled into an execution statement of the DSP control unit through C language;
S6. calculating lateral and longitudinal movement position control commands according to the extracted optimal movement path suitable for the helicopter and driving the movement of the helicopter, wherein after selecting the optimal movement path within a control period, the MCU control unit sends a lateral alignment position control command to a hydraulic drive system of a quick mooring device and a longitudinal towing position control command to a hydraulic drive system of a longitudinal towing device, and the quick mooring device and the longitudinal towing device drive the movement of the helicopter;
S7. repeating steps S1 to S6 until the automated towing, alignment and hangar of the helicopter is completed, wherein during an actual movement of the helicopter, the optimal movement path is compensated and adjusted according to a latest attitude of the helicopter within the control period, so as to ensure that the helicopter moves towards a hangar according to the extracted optimal movement path.