| Coal is an important part of energy in our daily life and an important raw material for industrial production.As one of the important systems in coal production,mine hoisting system is responsible for the transportation of coal,personnel and various equipment and materials.In the process of operation,once the main power supply system or main transmission system of the lifting system fails,and the technical personnel can not eliminate the failure to restore the normal operation of the lifting system in a short period of time,the lifting system will not operate,which has a very large potential safety hazard.Therefore,this paper studies the gravity lowering system which uses the unbalanced forces on both sides of the lifting system to realize the operation of the lifting system,and further improves the security level of the coal mine lifting system.Firstly,taking the multi rope friction hoisting system as the research object,based on the analysis of the gravity lowering movement process of the hoisting system,a set of gravity lowering hydraulic system with electro-hydraulic proportional relief valve as the core is designed.In order to further improve the adaptability of the gravity lowering system of the hoist,it is proposed to install a large gear ring on the hoist drum,and use the frequency conversion motor,reducer and small gear wheel to solve the problem that the tension difference on both sides of the hoist drum is too small to drive the system,so as to realize the auxiliary lifting of the hoist system.Secondly,the computer simulation software AMESim is used to model and analyze the whole gravity lowering control system,to study the working characteristics of the elevator gravity lowering control system,and to lay the foundation for the research of the control strategy of the gravity lowering process;the finite element analysis software is used to analyze the contact stress and modal analysis of the key components in the auxiliary drive assembly,to obtain the solid of the auxiliary drive It has frequency,mode shape and structural strength of key components,which provides reliable theoretical basis for practical application.Moreover,the real-time requirements of the gravity lowering process of the hoist are very high.The gravity lowering control system with STM32 as the core controller is designed,and the software and hardware of the system are designed.According to the control requirements of the gravity lowering control system of the hoist,thecontrol strategy is analyzed,and the fuzzy adaptive PID is adopted as the control strategy of the gravity lowering control system.Finally,based on the study of the control strategy of the gravity lowering system,the fuzzy adaptive PID controller is designed.The control effect of the control strategy designed in this paper is verified by the joint simulation of MATLAB +AMESim,and compared with the simulation results of the traditional PID control strategy,the simulation results show that the fuzzy adaptive PID control is more suitable for the gravity lowering control system of the elevator than the traditional PID control.There are 77 figures,13 tables and 80 references in this paper. |
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