The International Maritime Organization (IMO) proposed to reduce the total CO2 emissions of the maritime sector by 50% by 2050, and strive to gradually achieve the zero-carbon target. Therefore, shipping companies need to consider environmental impacts while pursuing benefits. In view of the tramp ship scheduling with speed optimization problem, considering carbon emissions, the configuration of owner ships and charter ships, and the impact of sailing speed on ship scheduling with the target of minimizing the total costs of shipping companies, multi-type tramp ship scheduling and speed optimization considering carbon emissions is established. A genetic simulated annealing algorithm based on a variable neighborhood search is proposed to solve the problem. Firstly, the ship type is matched with the cargo. Then the route is generated according to the time constraint, and finally, the neighborhood search strategy is adopted to improve the solution quality. The effectiveness of the proposed model and algorithm is verified by an example, which also confirms that ship scheduling and sailing speed joint optimization can reduce costs and carbon emissions. Research results can not only deepen the study of the theory of tramp scheduling but also to effectively solve the tramp shipping schedule considering carbon emissions problems faced by companies to provide theoretical guidance.

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In order to keep the flux constant when the asynchronous motor is running under load, especially under light load, a Glowworm swarm optimization (GSO) algorithm is proposed to control the voltage frequency ratio of the cycloconverter. Based on the analysis of the two variable control theory of the voltage frequency ratio of the cycloconverter and the working principle of the cycloconverter, the self-control method of the voltage frequency ratio of the cycloconverter by adaptive fuzzy backstepping sliding mode is proposed. In the control process, GSO and BFA are integrated to optimize the control process of the controller, and an adaptive selection strategy is adopted to ensure the adaptive step size of the firefly and improve the accuracy of the GSO algorithm. The experimental results show that when the optimal voltage-frequency ratio is switched between the online continuous frequency control strategy and the frequency range is small enough, the motor speed is stable, the speed regulation process is stable, and the motor is always in the state of high force index. It shows that the control method has a fast convergence speed and a good control effect on the voltage frequency ratio of the ring converter of the experimental motor, and it can keep the flux constant under light load.