Analysis And Countermeasures Of Blockage And Deadlock In Operation Of RGV In Plane Mobile Stereo Garage

The increasing number of cars and the shortage of land resources are the important problems of urban static traffic.The emergence of automatic stereo garage can effectively alleviate and solve such problems,save the vehicle access time to a great extent,reduce the waste of resources and makes parking more efficient and environmentally friendly.Planar mobile stereo garage is a form of automatic stereo garage.In order to optimize the operation efficiency of the garage and improve customer satisfaction,the design stage of the planar mobile stereo garage needs to plan reasonably the allocation of resources and equipment and avoid the risk of RGV(Rail Guide Vehicle)operation conflict in the system.Thesis or dissertation mainly studies from the following aspects:(1)Analyze and investigate the role of automatic stereo garage in improving urban static traffic problems;explain the current situation and shortage of domestic and foreign research on operation blocking and deadlock control strategy of RGV;and analyze and elaborate the importance of optimizing the blocking and deadlock control strategy;(2)Analyze the operation process of the access car in the garage according to the structure of the planar mobile stereo garage to get the 10 types of access car request in the garage and describe the operation scenarios.Based on the theory of queuing,put the limitation of the number of customers and RGV in the garage into consideration,and establish a semi-open queuing network model of planar mobile stereo garage.(3)The evaluation index of the planar mobile stereo garage is defined as the service time and operation energy consumption of the customer’s access car,according to the evaluation index of the stereo garage.The semi-open queuing network model of stereo garage is also optimized and solved.And to make the system run more efficiently,comparisons and analysis of the combination of different arrival rate and different RGV and lift number configuration are made through writing MATLAB simulation program.(4)Analyze and classify the causes of RGV operation blocking and deadlock in the system according to the multi-RGV operation environment in the garage.The blocking was divided into waiting blocking,single-path blocking and multi-path blocking.Deadlocks are divided into multiple path deadlocks,single path deadlocks and node deadlocks.The existing anti-collision control strategies in the system,such as zoning strategy and anti-collision path planning strategy,are also analyzed.Their principles and specific implementation methods are explained,and the advantages and disadvantages of each strategy are compared.(5)Algorithm A* is used to develop the system blocking and deadlock control strategy on the basis of generating the shortest RGV operating path in the system.The traditional banker algorithm is improved to pre-detect the blocking and deadlock phenomenon during RGV operation.By extending the time window,the blocking phenomenon was alleviated and deadlocks are eliminated.This method not only resolves the conflicts in the system,but also improves the operating efficiency and the utilization rate of equipment.