In order to accurately perform fault diagnosis of key rotating machines of rail vehicles, a new method for diagnosis was proposed, based on local mean decomposition-energy moment-directed acyclic graph support vector machine. The vibration signals of rotating machines were decomposed by local mean decomposition to obtain the signal components, and then energy moment is calculated for each state feature component for feature extraction. For state identification, the directed acyclic graph support vector machine is established, multiple classical support vector machine were trained, and then multi-state identification was completed using directed acyclic graph support vector machine. The proposed method was tested on a train rolling bearing. Experimental results show that the method has nearly 95% identification accuracy and verified the feasibility and advantages of this method.
ABSTRACT At present, the production workshop generally has the following characteristics: not-standardized layout, Cramped space and more working environment changes, Automated Guided Vehicle (AGV), in logistic, has the limitation of movement flexibility and intelligence, and cannot meet the logistics requirements. In this paper, a circular omni-directional mobile logistics platform with zero turning radius is designed by the four mecanum wheels structure. First of all, we devise the Mobile structure. On the basis, using relevant mathematical knowledge, the kinematic model and dynamic model of the platform are designed. Then, define the trajectory tracking error equation, and choose backstepping method to realize the trajectory tracking control. Finally, we simulate the nonlinear system dynamics using simulink, the graphical matlab workpace. The omni-directional autonomous motion of the robot is realized. It is an effective attempt to improve the intelligent of the logistics system.
According to the relevant theoretical methods of omnidirectional mobile mechanism, the kinematic model of omnidirectional mobile platform under theoretical conditions is established, and the dynamic model of omnidirectional mobile mechanism in actual environment is analyzed according to the specific situation of platform body structure and actual influencing factors. Based on the kinematic model, a backstepping based trajectory tracking control method for omnidirectional mobile platform is designed, and the trajectory tracking error equation is solved. In order to further improve the stability of the system, a fuzzy control system based on backstepping method is designed based on the dynamic model, and the control torque of the platform is selected. Finally, the effectiveness of this method is verified by numerical simulation.
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