Research On Fault Tolerant Control For Mine Hoist Wire Rope Tension Active Regulation System

Mine hoist is the throat equipment connecting the ground and underground mine,which is used to transport coal,personnel,equipment and materials.In the operation process of mine hoist,due to some inevitable factors,such as: the difference in the manufacture of the hoist drum,Inconsistent installation length of wire ropes and the difference in elastic stiffnesses of wire ropes,it is difficult to keep the tension of the two wire ropes consistent.Therefore,in order to ensure the safe operation of the mine hoist,a tension active adjustment system,which consists of two sets of electrohydraulic actuators,some necessary sensors and mechanical structure groups,are used to actively regulate tensions of wire ropes.The tension active regulation system can control two electro-hydraulic actuators to actively drive two movable head sheaves movement by two servo valves so that tensions of two wire ropes can be regulated to make the weight of congveyance is evenly distributed on two wire ropes,wich will prolong the service life of the wire rope and ensure the safe operation of the mine hoist.Moreover,once actuators faults or sensors faults of the tension active regulation system occurs,the performance of the control system will be reduced,which will result in serious accidents such as a decline in wire rope life and even rope being broken.These losses are immeasurable.Therefore,it is imperative to study the fault-tolerant control method for the tension active regulation system.Therefore,with the support of sub project and National Natural Science Foundation of China,the tension of mine hoist is carried out Fault tolerant control method of tension active regulation system is studied to ensure the safe operation of mine hoist.First of all,the mine hoist is summarized,and the causes of the tension difference of the wire rope are described.The overall model of the active tension regulation system is established by using the force control model of the valve controlled electro-hydraulic cylinder.The main fault types of the active tension regulation system are analyzed,and the leakage fault model of the hydraulic actuator,the constant deviation fault model and the variable gain fault model of the tension sensor are established.According to the active tension regulation system of mine hoist,the simulation test system of mine hoist is built,and the six section speed hoisting curve used in this paper is verified.On the basis of fault model,the leakage fault of hydraulic actuator,the constant deviation fault and the variable gain fault of tension sensor are analyzed under the condition of a PI control closed-loop.Response characteristics of three faults are obtained.Secondly,in order to deal with the modeling error between the tension of flexible steel wire rope and the pin force of hydraulic cylinder,a modeling deviation observer is designed to estimate and compensate the error online.Aiming at the external dynamic disturbance of the active tension regulation system,the dynamic disturbance observer of the active tension regulation system is designed to estimate and compensate the external dynamic disturbance on-line.On this basis,a detailed design of the backstepping controller for the tension active regulation system is given.And through the stability analysis,the control gain selection range of the modeling deviation observer and the dynamic disturbance observer is obtained.The simulation test verification is carried out to verify that the proposed controller can balance tensions of two wire ropes better than the backstepping controller and the conventional PI controller.Thirdly,for the fault-tolerant control method under actuator leakage fault,according to the system model under actuator leakage fault,an adaptive sliding mode observer is designed to diagnose and reconstruct the leakage fault.By defining the appropriate Lyapunov function,the stability of the proposed observer is proved in detail.Using the observation value of the observer,on the basis of the control strategy in Chapter 3,the fault-tolerant controller is designed to ensure that the active tension regulation system can still maintain a certain control performance under the condition of actuator leakage fault.Finally,the fault-tolerant controller is verified by simulation tests on the mine hoist with taking the No.1 hydraulic cylinder external leakage fault and the No.2 hydraulic cylinder internal leakage fault as examples.Finally,according to the system model under the constant deviation fault and the variable gain fault of tension sensor,the unknown input full order observer and adaptive full order observer are designed respectively,and the stability of the two observers is proved.Faults of the tension sensor is reconstructed by using the observation value of the observer,and the diagnostic criteria for the constant deviation fault and the variable gain fault of the tension sensor are formed.Based on the tension value observed by the observer,the corresponding fault-tolerant controller of tension sensor is designed based on the control strategy in Chapter 3,and its stability is proved.Taking the fault of No.1steel wire rope tension sensor as an example,the simulation test is carried out,and the test results verify the performance of the designed fault-tolerant controller.There are 101 figures,14 tables and 142 references in this paper.