Patent ID: 11966667
Assignee: HARBIN ENGINEERING UNIVERSITY
Field: Transport (Mechanical engineering)
Classification: CPC G  B | IPC B  G

Claim 3:
4. An intelligent simulation method for jacket towing, comprising:
executing, by at least one computer processor, a non-transitory computer readable storage medium, the non-transitory computer readable storage medium including executable instructions configured to cause the computer processor to perform the following steps:
step (1): starting, using the at least one computer processor, a distributed collaborative simulation subsystem to enable software and hardware communications of each subsystem and monitor an operation status of each federal member;
step (2): applying, using the at least one computer processor, a comprehensive management and evaluation subsystem to select a simulation training subject, set sea conditions, an initial position of a jacket, an initial position of a tugboat and initial parameters of a towrope, send the set parameters to a motion simulation subsystem and control start-stop of a simulation process of the system through network;
step (3): applying, using the at least one computer processor, an operation control simulation subsystem to set winch speed and tugboat control instructions through an operation handle and a control software according to simulation requirements, and send the winch speed and the tugboat control instructions to the motion simulation subsystem;
step (4): applying, using the at least one computer processor, the motion simulation subsystem comprising a six-degree-of-freedom motion simulation model of the jacket, a six-degree-of-freedom motion simulation model of the tugboat and a motion simulation model of the towrope to drive the six-degree-of-freedom motion simulation model based on the control instructions sent by the comprehensive management and evaluation subsystem and the operation control simulation subsystem, calculate a motion state of a coupling system in real time, and transmit simulation data to the comprehensive management and evaluation subsystem and a visual simulation subsystem; and
step (5): applying, using the at least one computer processor, the visual simulation subsystem to render training scene and operation equipment in real time and display the training scene and the three-dimensional operation equipment, based on marine environment data issued by the comprehensive management and evaluation subsystem and the simulation data calculated by the motion simulation subsystem;
wherein in step (4), force of the towrope on the jacket and force of the towrope on the tugboat are respectively introduced into motion equations of the jacket and the tugboat; an end of the towrope is regarded as fixed to the jacket, and a top of the towrope is regarded as fixed to the tugboat; node speeds and spatial positions of the end of the towrope and the top of the towrope are respectively kept consistent with node speeds and spatial positions of the jacket and the tugboat in a solving process, and the jacket, the tugboat and the towrope are regarded as a whole for coupling solution;
both the six-degree-of-freedom motion simulation model of the jacket and the six-degree-of-freedom motion simulation model of the tugboat take marine environmental loads and tension force generated by the motion simulation model of the towrope into consideration;
in step (4), the six-degree-of-freedom motion simulation model of the jacket is:

{right arrow over (F)}={right arrow over (F)}1+{right arrow over (F)}D+{right arrow over (F)}B+{right arrow over (F)}AM_M 

wherein {right arrow over (F)}1 is inertia force, {right arrow over (F)}D is drag force, {right arrow over (F)}B is buoyancy, and {right arrow over (F)}AM_M is added mass force;
the six-degree-of-freedom motion simulation model of the tugboat is:

Ms{dot over (v)}s+Cs(vs)vs+Ds(vs)vs+gs(ηs)=τes 

wherein Ms is an inertia matrix of a tugboat system, comprising a ship mass matrix and an added mass matrix, Ds(vs) is a damping matrix of the tugboat, gs(ηs) is a vector of force and moment caused by gravity and buoyancy, Cs(vs) is a Coriolis force matrix, and τes is thrust on the tugboat;
the motion simulation model of the towrope is:, [
     
      
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wherein mi is a mass matrix of node i, ai is an added mass matrix of the node i, T is tension at a node, C is internal damping force of the node, Wi is net buoyancy per unit length, Dpi is lateral damping force at the node, and Dqi is tangential damping force at the node.