Intelligent Control Method Of Port Tugboat For Energy Saving And Emission Reduction

An intelligent,low-carbon,and green shipping system has become the consensus of all countries in the world today.The Port is an integrated transportation hub,and harbor tugboats are the backbone of the port water services.Large-scale ports have large numbers of tugboats,high horsepower,frequent cross-port activities,many tasks,and heavy loads.Their green and intelligent development can substantially enhance the competitiveness of the port.The research on the intelligent control method of harbor tugboats for energy saving and emission reduction will help to solve the problem that restricts the delicacy management of port water services and provide a solid theoretical and technical foundation for the port carbon peaking and carbon neutrality goals.This research focuses on the energy-saving and emission reduction operation of the tugboat.For the two scenarios of no-load and variable load during escort design a green intelligent escort motion control framework.Considering the characteristics of the main engine of the tugboat and time-variable load to design an intelligent trajectory tracking algorithm based on model predictive control,and through the simulation to test the effectiveness of the proposed motion control algorithm.The main research and results are as below:(1)Focusing on the escort operation scenario,based on the background of green and intelligent shipping to design a new escort operation mode,and build a green and intelligent escort motion control framework.Through the coordinated path planning of the tugboat and the served ship to reduce the tugboat operation.Combined with the characteristics of the main engine,the green intelligent motion control strategy is determined and realizes the energy-saving control during the escort operation.(2)Considering the complex operating environment and the time-variable load of escort operation,a tugboat motion control method based on model predictive control is proposed.The tugboat operation path is planned considering the towing operation mode between the tugboat and the served ship.The motion model and load model of the tugboat are constructed.The trajectory tracking optimization problem of the tugboat is constructed based on the model,and the motion control strategy is determined.(3)Consider the fuel consumption efficiency of green intelligent motion control.To solve the energy-saving control problem of a tugboat in the frame,firstly,the conversion relationship between main engine fuel consumption and propulsion is calculated through the existing empirical formula.Secondly,based on the characteristics of the tugboat’s main engine to analyze the high-efficiency energy consumption range and the corresponding propulsion force and moment interval.Finally,combined with the tugboat motion control framework based on model predictive control and solve the tugboat green intelligent escort motion control optimal control strategy.The simulation results show that the path tracking accuracy of the designed tugboat motion controller based on MPC is high,and the position error of the model ship is between 0m and 0.2m,the heading error is stable.Under the scenarios of noload and variable load,the fuel consumption decreases by 7.23% and 13.08%respectively,and the energy-saving effect is obvious.There are some main innovation points in this article as follows:(1)A new operation mode of tugboat under the background of green intelligent shipping is designed to reduce the operating frequency of tugboat.Through the intelligent control algorithm,the tugboat operates in the optimal energy consumption state under various working conditions,which can effectively reduce the fuel consumption of the tugboat and achieve the goal of energy-saving and emission reduction(2)A motion control method based on MPC is established.Considering the three operation characteristics of complex and changeable tugboat operation environment,diverse tasks,and time-variable load to construct the optimal control problem of tugboat accompanying trajectory tracking and determine the tugboat motion control strategy.(3)An energy-saving and emission reduction method for tugboat escort operation is proposed.Without changing the hull design and adding ship equipment,by analyzing the characteristics of the tugboat main engine,extracting the high-efficiency interval,combining with the intelligent motion control algorithm based on MPC to realize energy saving and emission reduction.The research results can provide a useful reference for the intelligent movement control and scheduling of harbor tugboats,port energy saving and emission reduction,cost reduction,and contribute to the construction of world-class ports and make China into a country with a strong transportation network.