Under the background of a large scale of yard operations, with the aim of minimizing unbalanced workload among blocks, a collaborative optimization model for allocation of yard blocks and yard cranes was proposed by considering the influence of truck appointment information, which could allocate reasonable storage area for import containers and arrange loading and unloading yard cranes. The model was solved by CPLEX, and the experimental results of the optimization model considering truck appointment information and the traditional model without truck appointment information were compared, and the sensitivity analysis was also carried out in the aspects of truck appointment information, yards crane number, containers number and task split score. Results show that the unbalanced workload can be reduced by 20%~30% considering truck appointment information, which verifies the validity of the model and has guiding significance for the scientific management of the storage yard.

This paper summarized the standardization process and application status of electronic chart navigation system, analyzes the evolution of electronic chart navigation system from the dimensions of multidimensional, integration, openness, service and mobility, and introduces relevant key technologies such as multidimensional electronic chart, Internet of Ship, S-100 standard, e-navigation, intelligent service and mobile navigation APP. Under the development trend of intelligent ship, the prospect of the combination of environmental perception, augmented reality, VDES and autopilot with electronic chart navigation system was analyzed.

An improved velocity obstacle (IVO) algorithm for unstable obstacles was proposed for the autonomous obstacle avoidance of unmanned surface vessels (USV) with unstable obstacles , which conformed to the Convention on the International Regulation for the preventing Collision at Sea (COLREGS). The algorithm used the adaptive threshold of minimum encounter time and distance to optimize the judgment of obstacle avoidance state. The sliding window and forwardlooking line of sight were used to solve the problem of boundary jumping when entering and exiting the obstacle avoidance state due to the instability of obstacle information. The frequent switching of collision avoidance rules in obstacle avoidance was reduced by setting angle buffer. Then, the IVO algorithm was compared with the traditional VO algorithm in the selfdeveloped USV semi physical simulation system, and results show that the IVO algorithm has more advantages in boundary judgment and obstacle avoidance stability than the traditional methods, which proves the effectiveness and feasibility of the proposed algorithm.

In order to realize the parameterization and intellectualization of cabin layout, a multi-objective optimization model including the objective of logistics intensity between cabins, the objective of adjacent intensity and the objective of fixed position was established according to the characteristics of the optimization design of ship cabin layout. Based on the establishment of the mathematical model, the improved genetic algorithm based on the reverse learning optimization population generation method was used to solve the model. By expanding the search range of the solution, it can jump out of the local optimum and guide the population to find the global optimum. Finally, the simulation experiment was carried out by using the established optimization model and the improved genetic algorithm, and more reasonable results are obtained, which verify the feasibility and effectiveness of the proposed method.

In order to achieve reasonable load current distribution and nondifference regulation of bus voltage in shipborne DC microgrid energy storage system, an autonomous current sharing strategy based on the convergence of charge (SoC) of energy storage state was proposed. This strategy added a compensation outer loop on the basis of conventional droop control to adaptively adjust the load current and reference voltage by constructing a SoC convergence function in the loop, so that the load current was distributed reasonably with the dynamic equalization of the SoC and maintained a higher bus voltage level. The proof of SoC convergence was given in this paper, and the selection rules of related parameters were analyzed. Additionally, a sparse communication network architecture was built to reduce the communication pressure of the energy storage system, and the dynamic average consensus algorithm was used to estimate the global average SoC and made it converge stably. Finally, a StarSim hardware in the loop experimental platform was built, and the results show that the proposed strategy can achieve the control objectives of state of charge balance, load current sharing and DC bus voltage stability.

In order to solve the joint optimization problem of cabins and passage, the layout of cabins and passage was considered together. The position sequence of cabins and passage was taken as design variables, the weight of adjacent strength and flow strength between cabins as objective function, and the area and position of cabins and passage as constraints condition. Genetic algorithm was used to optimize the layout of cabins and passage. Dijkstra algorithm was used to calculate the shortest distance between cabins. Taking the ship living quarters as an example for comparison and verification, the optimization of the cabin passage layout with channel location involved in the layout design and the optimization of the cabin passage layout with channel location not involved in the design were carried out respectively. The results show that the linkage optimization method proposed in this paper is feasible, and the comparison results show that the linkage optimization has more advantages.

Aiming at the system composed of a cross-border e-commerce enterprise and a logistics enterprise, considering the random fluctuation of exchange rate and demand, a decision model of logistics enterprise’s pledge rate during the overseas market price sensitive was established to obtain the best pledge rate when the logistics enterprise provides inventory pledge financing. The impact of tariff rate, default rate of crossborder ecommerce enterprises, exchange rate and fluctuation of overseas demand on the pledge rate of logistics enterprises were studied. The results show that the tariff rate and the default rate of crossborder ecommerce enterprises are negatively correlated with the best mortgage rate; the best pledge rate of logistics enterprises decreases with the increase of basic demand and exchange rate fluctuation in overseas market, and the more sensitive the target overseas market price is, the faster it decreases. The result can provide a reference for logistics enterprises to formulate inventory pledge financing strategy.

In order to improve the rationality of the alignment design at the route design stage, the spatial curvature was used as the evaluation standard of highway alignment continuity, by using the VS as the development tool and the C# as the development language, the secondary development of Civil 3D was carried out. The evaluation model based on spatial curvature was established, and a highway alignment evaluation program for the continuity of alignment was developed, which can be used as an extension tool in civil 3D. The program was used to evaluate the alignment continuity of Luotuolazi—Qingyoutun highway in Heilongjiang province. The results show that the proposed highway alignment continuity evaluation program can quickly calculate the spatial curvature and evaluate the alignment safety, which can provide reference for the alignment optimization of highway projects.

In order to explore the effects of the tacit collusion of upstream ports on the carriers' endogenous timing and competition strategic variables in the maritime
In order to explore the effects of the tacit collusion of upstream ports on the carriers’ endogenous timing and competition strategic variables in the maritime container transportation chain, the motivation and stability of the tacit collusion of upstream ports under different competition mode of downstream shipping companies were analyzed in infinitely repeated games. Furthermore, the dual endogenous choices equilibrium of the shipping companies’ endogenous timing and strategic variables was solved. The results show that port collusion is the easiest to sustain under simultaneous quantity competition of shipping companies, but the most difficult to maintain under the BertrandCournot mixed competition where the shipping companies act at the same time. The shipping companies’ dual endogenous choices are not only related to the substitution of transportation services but also to the port discount factor. In equilibrium, carriers can engage in quantity competition with three kinds of move time modes, mixed competition of simultaneous actions, and the mixed competition where the liner competes in quantity as the leader while another chooses price as the follower. The research in this article can also provide a basis for the development and reform and transportation departments to strengthen the identification of ports tacit collusion.

CMA(p,q), a blind equalization constant modulus algorithm, is widely used in digital communication. Its parameters p and q were generally selected as positive integers 1 and 2. In order to adapt to a more general environment, it is necessary to extend the values of parameters p and q from integers to ordinary positive real numbers. Different from the traditional performance analysis method which was to recursively derive the covariance matrix of the weight error vector, based on the energy conservation relationship, the error function was directly expanded by Taylor series, and the principle of separation hypothesis was used to derive the general steady-state closed analytical expression of CMA(p,q), and an ideal mathematical model for p,q values in the selectable range was established. The simulation results show that the simulation values of complex or real data match well with the theoretical values.

In order to provide an important reference for vehicle scheduling optimization and truck reservation system design, a shortterm prediction method of truck turnover time based on data mining was established by using the collected data of a port in Shenzhen. Firstly, by analyzing the data of the terminal gate, the truck operation characteristics such as vehicle arrival time distribution, task type, the operation mode and the turnover time of the truck in the terminal were obtained. On this basis, the mapping relationship between truck operation characteristics and turnover time was established by using recurrent neural network (RNN) and training set data. Secondly, in order to reduce the impact of random fluctuations on the prediction of turnaround time, the wavelet decomposition algorithm was used to separate the residual of the fitting results of the recurrent neural network with highfrequency noise, and the filtered lowfrequency series was fitted by the autoregressive model. Finally, the combined model of the fitted cycle neural network and the autoregression model (AR) was established to support the shortterm prediction of the truck turnaround time, and verified by test set data. The results show that the combined model can greatly improve the prediction accuracy compared with the single RNN.

In order to optimize the energy management strategy and the capacity parameters of the composite energy storage system of a fuel cell hybrid ship, a simulation model of the composite power system and the energy management system including the composite energy storage system was built in the MATLAB / Simulink environment, and optimized by the ant lion multiobjective optimization algorithm, the performance of the optimized composite system was compared with that of the original ship. The results show that the optimized composite system can meet the power demand, improve the power quality and extend the service life of the equipment.

In order to better make the conversion interface between Revit and ANSYS software suitable for structural analysis of longspan complex bridges such as cablestayed bridges, based on Revit 2019 and Revit API technology, the BIM model of the cablestayed bridge was transformed into an ANSYS finite element model with different element types by using C# language for secondary development. Among them, the main beams, piers and supports were transformed into solid elements, and the stay cables were transformed into rod elements. And through graphical user interface (GUI) development and database development, meshing, applying constraints, applying loads, solving and postprocessing operations were directly performed based on the Revit model. The transformation from BIM model to ANSYS finite element model and the automation of structural static analysis were realized, and the main bridge of Changshan bridge was taken as an example to verify. The results show that this method can realize the accurate conversion between BIM model and different element finite element models. Through the GUI interface and the operation of the Revit model, the bridge designers can more quickly and effectively carry out the structural stress analysis, which lays the foundation for improving the work efficiency and information level of the bridge industry.

In order to solve the problems of complicated operation and high cost existing in traditional preparation technology, the pure phase lithium titanate (LTO) / copper foil (Cu) thin film electrode without adhesive was successfully prepared by microelectronic ink jet printing combined with high temperature annealing. Scanning electron microscope analysis results show that the pure phase LTO with nanoparticle shape can be uniformly deposited on the surface of Cu. The button cell assembled with 10 layers of active material LTO / Cu film electrode and Li negative electrode by inkjet printing has a specific capacity of 91.27 mA·h/g at 3C (1.0 ~ 1.7 V) current density, and after 1000 cycles, the retention rate of discharge specific capacity is 85.4%, which show excellent cycle stability. The above results show that the method of inkjet printing combined with high temperature annealing has a broad application prospect in the preparation of electrode materials without adhesive.

To explore the temporal and spatial evolution characteristics and influencing factors of the development of the Bohai rim port group, based on the entropycatastrophe progression method, a comprehensive evaluation index system of port development was constructed from three aspects as internal control, exogenous and potential. The ArcGIS software was used to investigate the temporal characteristics and spatial differences of development of the Bohai rim port cluster from 2000 to 2018. By combining with the diagnosis model of obstacle factors, the main influencing factors restricting port development was analyzed. The results show that the development of the Bohai rim port cluster has phase characteristics, and there are significantly differences in the development of each port, but the overall development potential is great. There are some differences in the factors that restrict the development of port groups and ports in different development stages, but it mainly concentrates in container throughput, total foreign trade import and export, and foreign trade throughput. In recent years, the influence of urban development and financial support has been gradually strengthened. The results help to understand the development process and influencing factors of the Bohai rim port group, and provide a reference for realizing the highquality coordinated development of the port group.

To prepare fluorescent hydrogels with excellent properties, P(BAcFAM)/PEG was prepared by free radical solution polymerization with acrylamide（AM）, PEG and bisacryloxyfluorescein (BAcF) as raw material and N,N′methylene bisacrylamide, ammonium persulfateN,N,N′,N′tetramethylethylenediamine（APSTEMED）as redox initiator. The structure of monomer and gel were characterized by FTIR and 1HNMR, and the effects of the concentration of AM and amounts of PEG on mechanical properties of hydrogels was studied. The results show that the mechanical properties of the hydrogels are significantly improved by the addition of PEG. When the amount of PEG added is 8% of AM mass, the tensile strength of the hydrogel reaches up to 0.45 MPa, and the strain is about 1190%. At the same time, the hydrogel show bright green fluorescence under 365 nm ultraviolet lamp, and obviously quenches in a certain concentrations range of Fe3+ in water, which can be used to detect the concentration of Fe3+ ions in water as a portable fluorescent probe.

In order to optimize the comprehensive performance of butanol / diesel electronically controlled diesel engine, firstly, the combustion chamber model of blended fuel engine was established by AVLFIRE, and the accuracy of the model was verified by comparing the simulation value with the bench test value. The influence of butanol mixing ratio and EGR rates on engine performance was simulated. Then, five important factors were arranged to optimize the multi parameter matching by orthogonal experimental design, and the indicated power and NO emission were taken as evaluation indexes, with weights of 0.4 and 0.6 respectively. Fuzzy mathematics analysis was used to analyze the simulation results, and the results show that the order of influence on comprehensive performance was: EGR rate (a2), butanol mixing ratio (a1), intake temperature (a4),intake pressure (a3), injection advance angle (a5); the optimal parameter combination is: a1=10%,a2= 12.5%,a3= 0.223 MPa, a4= 335.15 K,
a5= 20.6 °CA. The indicated power of the combination is 53.8 kW, which is slightly lower than that of the original 55 kW. The mass fraction of NO emssion 2.2×10^-4% is 74.1% lower than that of the original 8.5×10^-4%. The optimization method can meet the dynamic performance and at the same time achieve the purpose of effectively reducing NO emissions.

Aiming at the problem of mobile robot autonomous exploration and map building  in the unknown indoor environment, a mobile robot autonomous exploration method based on the octree map was proposed. Firstly，the frontier points were grouped and the key frontier points were extracted to generate candidate points. Then, two generation methods of candidate exploration point were proposed respectively based on the key frontier points and the accessible space, which were used for different stages of autonomous exploration.Next,the nonlinear combination of information gain and driving distance was used to construct  benefit function to evaluate candidate points, and the optimal candidate point was selected as the next target point.Finally, the octree map was updated by using the RGB-D data. The simulation and physical experiments verify the effectivity of autonomous exploration method.

The composite system synergy model was used to calculate the  development order  degree of the three subsystems of Guangdong, Hong Kong and Macao and the synergy degree of industrial development in Greater Bay Area. The results shown that from 2009 to 2016, the order of industrial subsystems in Guangdong-Hong Kong-Macao Greater Bay Area reached a high level, and the synergy degree between the three places is at fluctuation of low level . In 2016, Guangdong-Hong Kong-Macao Greater Bay Area, Hong Kong has the highest level of industrial development, and the Guangdong-Hong Kong industry has the highest level of synergy. There is large rising space for synergy improvement of industries synergies between the three places. It is necessary to deepen the industrial cooperation of three places, and constitute  a rational industrial synergy development mechanism to form a sound industrial chain to promote the coordinated development of the industrial system in Guangdong, Hong Kong and Macau.

Aiming at the prediction problem of metal contact sealing performance,the orthogonal experimental method was used to fit the functional relationship between surface topographical parameters, applied load and contact area ratio based on the numerical representation of rough surface and finite element contact analysis.Combined with the grid model of percolation theory, the variation rule of seal leakage probability with contact area ratio was simulated by using automatic path-finding algorithm. Therefore, a quantitative analysis method for predicting the relationship between rough surface topography with applied load and sealing performance was established, which can provide guidance for designing metal contact seal.

In order to scientifically formulate cross-regional dispatching scheme, based on the consideration of the dynamic relationship between enterprise sales price and market demand, a dispatching optimization model was constructed by taking the maximum profit of gas sales enterprise as the objective function. The example was solved by LINGO software, and the influences of market structure and price strategy on the dispatching scheme were analyzed. Results show the characteristics of cascade flow of gas dispatch agreement customers-oriented , while the market customers-oriented gas dispatch mostly concentrates on the nodes of higher sales price.Moreover, when the market demand cannot be fully met, the profit of the gas dispatch scheme under dynamic price strategy is higher than that under static price strategy. This study can provide reference for large gas sales enterprises to formulate the dispatching plan.

Aiming at the influence of wave on resistance of large square caisson during towing, numerical simulation of towing resistance of caisson under different flow velocities and wave heights was carried out by using computational fluid dynamics (CFD) method. The results show that the towing resistance of caisson fluctuates with the course of caisson heading, breaking and passing through waves. At the same velocity, the towing resistance of the caisson increases with the increase of the wave height. The towing resistance variation of the caisson with the wave height was basically the same at different current rates. The increase of the caisson towing resistance was proportional to the square of the wave height. The calculation of drag increment percentage shows that the percentage of drag increment is close to or more than 5% when the wave height exceeds 2 m. Therefore, it is suggested that wave height should be used as one of the factors for calculating the drag of open caisson in project.

In view of the current situation that  dynamic design information management of tunnels is still designed only from different data types and structures,in order to avoid the difficulty of information sharing caused by data heterogeneity to realize  the integrity and validity of information data sharing and exchange in the whole  life cycle of tunnel engineering,this paper  expounded the method of IFC standard expansion, and based on the existing IFC standard to select the tunnel structure as the study object, and the IFC standard was expanded in tunnel field from the aspects of tunnel spatial structure, physical elements and attribute set,and the data description field of IFC standard was expanded. On this basis, the parameterized tunnel feedback analysis model was developed by using the Revit software, then, a complete process and method for building information integration model of tunnel dynamic design have been completed. The validation results show that a more perfect information integration model of tunnel dynamic design can be established based on this method. The proposed integrated model has been successfully applied to the  dynamic feedback analysis management system of tunnels.

In order to plan the renewal scheme of  dry bulk fleet  of shipping company under the policy of ship dismantling subsidy, a fleet planning model of dry bulk fleet was established with the objective of maximizing shipping company’s profit.Taking the dry bulk cargo fleet of COSCO as the research object, the demand of dry bulk cargo transportation  in the next five years was forecasted,and the strategy of dismantling and new construction of dry bulk cargo ships  with or without subsidies was formulated by stages.By comparing fleet renewal schemes with or without subsidy,the impact of subsidy on the dismantling and new dry bulk carriers of shipping companies has been cleared as well as the effects of subsidy on improving the profitability of shipping companies. The result shows that the subsidy policy can promote the early dismantling of old ships.Under the simulation of subsidy policy,the amount of ship dismantling and shipbuilding increases substantially.The study can help the government and shipping enterprises to clarify the policy effectiveness of ship dismantling subsidy,and promote shipping companies to use the subsidy policy to update ships and improve market competitiveness.

The maneuverability of a rescue ship NHJ111 in short-crested irregular waves in deep water was studied. 3DOF nonlinear maneuvering equations were established by using the unified model. The resistance and propulsion dynamics were modeled by classical methods as well as forces and moments of the propeller, rudder and viscous crossflow. The method of Green function source was adopted to solve the boundary value problem (BVP) in frequency domain, and the mean wave drift forces were calculated by far-field formulas along with numerical verification. After that, the equations of motion were applied to NHJ111, and the turning motion in calm water was performed. It is found that the calculated results are in good agreement with the experimental data of the real ship, and the relative error is less than 8%. Then the turning motion simulation was numerically calculated in short-crested irregular waves in the sea state 6 in consideration of drift force. Accordingly, the established model is capable of simulating ship motions in waves with good precision and can be utilized in the rescue ship simulator. It lays the foundation for predicting rescue ship motions in rough sea.

To improve the prediction effect of non-linear BDI, the single-step and multi-step prediction results of various prediction models for BDI index were analyzed,and the VMD-FFT-LSTM combination prediction model was constructed based on the idea of "decomposition-reconstruction-prediction". Firstly, IMF components of BDI were decomposed by using VMD algorithm. Then, the IMF was reconstructed based on the BDI exponential cycle theory and the periodic results calculated by the FFT algorithm to achieve the purpose of noise reduction. Finally, the LSTM model was used for multi-step prediction of reconstruction sequences. Compared with the multi-step prediction results, it was shown that the prediction results of the VMD-FFT-LSTM combined model have better accuracy and stability,which solved the limitation of SVR model that the multi-step prediction results are prone to large deviation at the local extreme points of the sequence.

In order to solve the problem that the conventional Mamdani fuzzy control cannot achieve the expected target value resulted from static error in submarine vertical motion, an automatic steering fuzzy controller with integral function was designed. By introducing intelligent integral criterion,  the submarine controller can satisfy the motion control requirements of depth-keeping and depth-changing at the same time. The control effect of submarine vertical motion under the condition of periodic continuous disturbance and complex motion was simulated and analyzed,and the results show that the intelligent fuzzy control has good adaptability and maneuverability for all kinds of depth-keeping and depth-changing motion of submarine vertical plane,which provides certain reference significance for the design and improvement of submarine control system.

In order to analyze the characteristics of ship traffic flow in Chengshanjiao routeing waters,the  AIS shore-based system was used to collect the position data of ships passing through the waters of the Chengshanjiao channel navigation system.The local density of each ship's position points has been calculated by using the neighborhood information of these position data points to extract the navigation hotspot areas of the ship in the waters with channel navigation system at Chengshanjiao. On this basis,the characteristics of ship traffic flow in Chengshanjiao waters were analyzed, including the navigation preferences of ships of different tonnage,ships going south and northward, and the dynamic changes of ship navigation preferences in different time periods.The results show that local density reflects the local  information characteristics of ship position data points, which can reveal the relative tightness between ship location points and their adjacent location points,which can effectively solve the identification problem of ship traffic flow characteristics and realize the analysis and comparison of  dynamic changes of ship traffic flow in time and space.

In order to support the rational distribution of oil spill emergency resources in coastal ports, a gravitational model and a social network analysis(SNA) method were used to construct an associated network model of oil spill emergency resources based on port oil throughput.The role of port based on oil throughput in the network were studied by using network characteristics such as network density and centrality to analyze the port oil spill emergency resource layout requirements. The results show that the network correlation degree is 1, the ports with higher individual network centrality are evenly distributed in the Pearl River Delta,Yangtze River Delta and Bohai Rim region, as the core position of the region.There is a reflexive relationship between the plates,and there are many internal correlations to form a cohesive subgroup. Therefore, the layout of port oil spill emergency resources should be integrated, and enhance the cooperation between the ports. And hierarchical grading plays the radiation role of central port .Regional division is used to optimize the construction of regional emergency response capacity.

In order to explore the influence of the axial partition cooling mode on the frictional power loss of cylinder liner-piston ring, in consideration of the asymmetry of cylinder liner circumferential direction and surface roughness of cylinder liner and piston ring, a three-dimensional transient lubrication mathematical model of cylinder liner and piston ring was established, and then used to investigate the influence of the axial partition cooling mode on the frictional power loss of cylinder liner-piston ring. The results show that the enhanced cooling on the upper part of the cylinder liner can significantly improve the lubrication of the piston ring near the top dead center. As result, the wear of the cylinder liner and the piston ring is reduced, and the working reliability of the cylinder liner-piston ring is improved. When the thermal barrier coating is deposited on the middle of the cylinder liner, the minimum oil films at the middle of the stroke and the bottom dead center are all decreased. When only the enhanced cooling on the upper part of the cylinder liner or the thermal barrier coating around the middle of the cylinder liner is conducted, the average friction loss power increases slightly. The average friction loss power decreases, if both the enhanced cooling on the upper part of the cylinder liner and the thermal barrier coating around the middle of the cylinder liner are conducted.

In order to improve the searching and discovering probability of inland river falling personnel by unmanned aerial vehicle（UAV）, a maritime UAV system for inland water searching and rescuing was built. The relationship between UAV flight altitude and camera view field and camera visual imaging was analyzed, and by combining with the theory of visual attention, the regularity of searching people falling into water on the map display screen of ground stations for searchers was studied，and the maximum speed model of UAV and the discovery probability model of dropping personnel were established. The experimental results on the Yangtze River show that the maximum speed model of UAV and the probability model of dropping personnel are reliable for improving the efficiency of inland waterfall personnel.

In order to ensure the safe passage of the ship in the narrow and complicated construction waters, an improved genetic algorithm for route optimization based on Dijkstra algorithm and Maklink method was proposed. Firstly, the construction waters environment model was established by the improved Maklink method. Then the Dijkstra algorithm was used to get the initial reference path. Finally, on this basis, genetic coding iterative optimization was carried out to obtain the optimal path. The ship traffic degree and route risk were proposed, which were used as the evaluation basis for evaluating the advantages and disadvantages of narrow space and route planning in the passage waters respectively. The simulation results show that the proposed method greatly improves the safety of the route and ensures the shorter path distance as far as possible. The feasibility and validity of the proposed method were verified.

Aiming at  the problem of the ship course tracking, considering the characteristics of the rudder servo system, the dynamic parameter uncertainties of ships and the unknown time-varying environmental disturbance, a ship course tracking control law was designed by using the state feedback linearization principle and the basic thought of the extended state observer (ESO). Firstly, the nonlinear coordinate transformation was carried out for the ship steering mathematical model with an actuator. Then, the ESO was constructed to estimate the total disturbance due to the dynamic parameter uncertainties and the unknown time-varying environmental disturbance. Based on the above, the ship course tracking control law was designed by using the state feedback linearization principle. The theoretical analysis shows that the estimation errors of the constructed ESO asymptotically converge to zero, and the designed ship course tracking control law makes the closed-loop course tracking system of ships be stable and the ship course tracking error asymptotically converge to zero . Finally, a warship was taken as an example for simulation.The simulation results show the effectiveness and the robustness against the disturbance  of the designed ship course tracking control law.

Research on ship automatic berthing control in the domestic and abroad was introduced. Combining the ship automatic berthing research with the “shipbuilding industry 4.0” and “e-Navigation” project of IMO, the development of ship automatic berthing trends to be unified model, intelligent control, whole process of berthing, accurate measurement and engineering realization.

In order to clarify the impact of carbon emission limit and carbon tax rate on the path selection of refrigerated container multimodal transport, a dual objective path selection model with the lowest total transportation cost and carbon emission was constructed based on the constraints of transportation time and considering the impact of factors such as transportation speed and deadweight tonnage on carbon emission. A hybrid algorithm of genetic algorithm and simulated annealing was designed to solve the problem, and the scenario was discussed by using a study simulation. The results show that for refrigerated container transportation, increasing the transportation speed will increase the carbon emission and reduce the total transportation cost, and the increase of vehicle tonnage can reduce the unit carbon emission in transportation; changing the carbon emission limit and carbon tax rate can reduce carbon emissions in transportation and guide multimodal transport decision-makers to choose low-carbon transportation routes. The model can provide a theoretical basis for multimodal transport operators to make green path decisions.

A dynamic collision avoidance method based on the improved particle swarm optimization (PSO) algorithm was proposed for the dynamic collision avoidance problem of “LanXin” unmanned surface vehicle. Firstly, as the different aspect ratio of obstacle contour, the obstacle was expanded into a circle and an ellipse to acquire the collision avoidance model by using the principle of velocity obstacle. At the same time, the international rules of collision avoidance were added in the process of collision avoidance. Secondly, the PSO algorithm was improved adaptively, so that the calculation of collision avoidance strategy can quickly converge to the optimal solution, and improved the convergence speed and accuracy of algorithm for satisfying the rapid requirements of the collision avoidance algorithm. Finally, a virtual visual simulation platform was built to simulate the marine environment in navigation，and taking the “LanXin” unmanned surface vehicle as the simulated object to verify the efficiency of the proposed avoidance algorithms. The simulation results show the feasibility and effectiveness of the proposed collision avoidance method, which provide a feasible and effective solution for the autonomous dynamic collision avoidance of unmanned surface vehicle.

The r ese arch sta tus of  aut onomo us c ollision  av oid- ance tech nolog y for marine v essel s at hom e a nd abroad in re- cent years was sum marized. The meth ods of aut omat ic collision a voidance we re di vided in to three cat egori es and the research prog ress of each ty pe of met hods as we ll as the 
devel- opm ent and application of collision avoid ance system f or marine ves sels were analyzed re spectively . The uns olved prob- lems in the research of ship collision avoidance technology wer e summar ize d, incl udin g collisio n avoida nce decisio n-mak- ing pr oblems in nar row and crowded w aters, mul ti-ship au ton- omous co ordination collision avoida nce problems base d on in- form ation exc hange be tween ships , coordin ation and integra-tion prob lems be tween au ton omou s co llision avoida nce system and ship control system , as well as intelligence , reliabi lity and com pleteness testi ng pro blems of a uton omous co llision a- voidance system. This paper elaborated t he r esea rch tren d of auto matic co llisio n avo idance techn olo gy, and pu t fo rwar d the core theories a nd key techn ologies t o be solve d in the next step, in cluding mu lti-vessel c ollision a voidance the ories and efficien t algorithms combining mach ine lea rn ing in co mplex wate rs, self-ad aption integr ation and fu sion of differ ent colli- sion av oidance al gorith ms, interactive colla bor ation t heories between intel ligent ships an d traditio nal ships i n mixed traffic env ironme nt, i ntegr ation of collisi on avoidanc e decisi on-mak- in g system and ship mo tion contro l system , and testing theories of a utonomous collision avoidance system , etc.

Aiming at fleet deployment issue and cargo allocation issue under the background of COVID19 epidemic and the “dual carbon” strategy, in order to meet the requirements of liner companies for the balanced development of fleet transportation efficiency, economic benefits, service quality and environmental benefits, a multiobjective fleet deployment and cargo allocation optimization model was established to achieve the goal of maximizing fleet average space utilization and operating profit, minimizing cargo time value loss and single container carbon emission. According to the internal relationship between subproblems, the model was decomposed into a twolevel model. The upper level was mixed integer nonlinear programming to deal with route ship allocation and speed optimization, and the lower level was linear programming to deal with cargo allocation. The solution algorithm was designed based on NSGAⅡ algorithm framework. Taking the fleet of a liner company as example, the results show that the model and the optimization solution method are feasible, and the liner company can adopt the mixed strategy of slightly increasing the speed and increasing the number of small and mediumsized ships to achieve the effect of carbon emission reduction while meeting more freight demand and coping with port congestion.

Aiming at the problem of shipping schedule design of container liner transportation under the imbalance of cargo flow, according to the functional relationship between fuel consumption, vessel speed and cargo weight in each segment, and combined with the collaborative agreement of vessel arrival multi time window, multi departure, arrival time and multi handling efficiency, a nonlinear programming model for liner transportation vessel schedule design was constructed to optimize the speed of each segment, and the linear secant approximation method was designed to solve the model. Taking the AWE1 route served by CHINA COSCO SHIPPING GROUP as an example, the values of 100 scenarios were generated for simulation calculation. The results show that the optimization of vessel scheduling considering imbalance cargo flow can effectively reduce the total roundvoyage cost of container liner shipping, which  conduct to increasing the shipping capacity. The sensitivity analysis results show that the proposed model is beneficial to slow down the rapid increase of total liner voyage cost caused by the increase of fuel price, and larger the cargo flow imbalance coefficient, more effective the model. The conclusion can provide useful reference for vessel scheduling decision of shipping companies.

In order to ensure the high dynamic and accurate tracking of the desired trajectory, an optimal trajectory tracking control strategy with specified performance based on reinforcement learning was proposed for the an unmanned surface vehicle (USV) trajectory tracking system with input saturation limit. The hyperbolic tangent function was used to approximate the saturation function, and by the specified performance control technique, the tracking error of the unmanned ship was transformed, so that the tracking dynamic error was constrained within the expected specified range to ensure the high dynamic performance of the trajectory tracking system. On this basis, the optimal control theory and the actor critical control framework based on neural network in reinforcement learning were used to design the optimal control method of unmanned ship trajectory tracking, and the problem of control input saturation limit was solved. Based on the Lyapunov stability theory, the stability of the proposed trajectory tracking system under the control strategy was proved, and the tracking error was guaranteed within the specified range. Simulation results also verify the effectiveness and superiority of the proposed strategy.