Image segmentation and feature extraction are the premise for machine vision system to analyze and identify the image. Threshold image segmentation algorithm according to the method of two dimension threshold has a lot of calculation in calculating the threshold, and the minimum error threshold method can not use the spatial information of image. This paper presents an improved quantum-behaved particle swarm optimization based on the night segmentation and feature extraction technology. This paper introduces the QPSO algorithm based on multi group and multi stage improvement. The QPSO optimizing algorithm gradually approaches the global optimum threshold value to achieve better convergence and stability. An algorithm of vision image segmentation and feature extraction based on improved quantum-behaved particle swarm optimization is designed. Experimental results show that the optimization process of this algorithm has less control parameters and faster convergence speed.
Although the low-thrust liquid oxygen/methane rocket engine has broad application prospects, the low flame propagation speed and low combustion rate of methane fuel make the liquid oxygen/methane engine still face key technical challenges. Methane fuel is partially converted into hydrogen and ethane with higher combustion rate before being injected into the combustion chamber, which is positive for the use of dielectric barrier to improve the combustion performance of the engine. Therefore, this paper studies the effect of the main four products of dielectric barrier discharge reforming with methane conversion rate of 10%, on the flow field of the combustion chamber. The results show that the addition of reforming products can effectively improve the combustion efficiency of the engine. H2 in the reforming product can also improve the specific impulse performance of the engine by increasing the total pressure of the engine chamber. C2H4 will not affect the maximum temperature of the engine, However, it can expand the medium-high temperature range of engine temperature to different degrees. The addition of H2 accelerates the oxygen consumption rate, which provides a feasible way to reduce the design size of the engine and improve the combustion efficiency of the low-thrust engine.
This paper constructs a dynamic model of a four-wheel drive electric vehicle, which contains a vehicle model and a brushless DC motor model. In order to improve the starting and acceleration performance of the electric vehicle, we design a speed and current double closed-loop speed control system based on the constructed dynamic electric vehicle model. The starting and acceleration process of the electric vehicle is simulated and analyzed by CarSim-Matlab/Simulink co-simulation. The effectiveness of the speed control system is evaluated by the co-simulation results. In addition, the robustness of the speed control system is also analyzed for different vehicle masses.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.