Study On Dynamic Characteristic And Control Method Of Driving System For Fully Mechanized Heavy Armored Face Conveyor

As one of the key fully-mechanized conveying equipments,armored face conveyor?AFC?can not noly realize the coal transportation,but also support the shearers or coal cutters.The dynamic characteristics of AFC are time-varying,coupling,non-linear and heavy load.At present,large capacity,long distance,high power,high strength,long life and high reliability,and intellignet control have become the development trend of the fully-mechanized AFC.Although the domestic AFC has basically achieved the domestically produced of the whole machine,it has initially satisfied the rapid development of the coal industry in the product performance,service quality and other aspects.However,in terms of core technologies,the related scientific problems,theoretical and technical foundation are still very weak.So,the study on dynamic characteristic and control method of driving system for fully mechanized heavy AFC has very important theoretical and practical significance,in order to realize the multi-motor driving technology?e.g.power balance of multi-motor driving,extension of generic technology?,energy-saving running and intelligent control?e.g.transmission or driving characteristics with different coupling ways?,and to perform the dynamic coupling and adaptability of new composite systems?e.g.magnetic coupler?.For fully mechanized AFC,the key scientific issues about the load characteristics,the transmission?or driving?characteristics and response law with different coupling ways,the dynamic characteristics of multi-motor driving in complex working condition,the control strategy and algorithm of intelligent driving system,were studied and verified indirectly the accuracy and applicability of the found model with relevant scientific methods?e.g.simulation tests,literature comparison,etc.?.The major contributions with respect to its related scientific issues are listed as follows:1)Combined the analysis of the cutting load behaviors of the shearer matching AFC,the unloading characteristics of the shearer was obtained,i.e.,the varying curve of cutting capacity with shearer's haulage speeds,and through the literature comparison,for the consistent coefficient within interval[2.5,4],the formula can be used to calculate the prediction of the capacity of coal falling from the drum.Then,taking the granular properties of bulk materials as the approaching point,the free body diagram of quadrangular prism ACHG?i.e.tiny unit?was performed according to the limit equilibrium of granular materials,and the formula of interaction force between the strickle and the granular materials was deduced,but also the formula of meeting the strickle pitch,thus the frictional characteristics of load was obtained.In addition to analysis of the chain driving polygon effect and the dynamic load caused by the start/braking process,the impact of lump coal on the machine was also analyzed based on the contact mechanics theory.So,impact behaviors of load were deduced,and it was concluded that the impact angle,?_c,should be taken 82°for the solution of the maximum contact force.And unbalanced load distribution also was studied.The above work about the analysis of load characteristics can provide theoretical foundation for the transmission?or driving?characteristics with different coupling ways and the dynamics in complex working condition.2)The mathematical model of transmission torque?or power?for each soft-start device?e.g.CST,hydrodynamic fluid coupler,variable-frequency drive,magnetic coupler,etc.?was established and the variation law of transfer torque?or power?function was analyzed by controlling the relevant adjustment parameters.Based on the load characteristics of AFC,the coupling response behaviors of transmission or driving with different coupling ways were compared,and it was concluded that variable-frequency drive?VFD?has obvious advantages for the realization of intelligent driving,that is,the adjustment of the fundamental frequency,f₁,can achieve the effect of energy saving or increse the conveying efficiency.From the coupling cruves,the best working point for each coupling way was theoretically obtained.3)Analytical and numerical analysis of equivalent stiffness coefficient of sprocket and scraper chain was carried out based on COMSOL.On this basis,the dynamic formula of chain driving system was established using Kelvin-Vogit mode,and the dynamic simulation of chain driving system in typical working conditions?e.g.start-up with full load,power off,unexpected chain jam?also was performed using MATLAB/Simulink software;then,the dynamic characteristics in above mentioned there conditions were obtained.Next,the simulation tests of random vibration and impact were proposed,and the behaviors of the random vibration and impact of chain driving system were analyzed synthetically.The strength of key component?e.g.scraper chain,sprocket,etc.?and the response of displacement,acceleration and stress in key point were obtained.After that,the dynamic model of a equivalent kinematic chain of automatic telescopic tail of AFC was established,and the dynamic characteristics,prediction and response law of automatic telescopic tail were described comprehensively.Finally,the kinematic and dynamic analysis of driving system of AFC with multi-motor in ten working conditions was studied based on dynamic similitude theory.The above work can also provided useful insights for the study of industrial tests and control strategies.4)The adaptive inverse control method was established based on RBF network;then,taking variable-frequency drive of AFC as an example,the control method was simulated,and,it shows that the error of the system response curve is small,and it has strong robustness for disturbances.After that,for the unbalanced load distribution of double-motor driving of AFC,the SMVSC based on RBF network was established.The Lyapunov energy function was founded,and it verified the stability of the system.A quick analysis was also made with the common LMS algorithm.Simulation results indicated that RBF-SVC has the certain advantages of fast convergence and high anti-interference capability.Finally,for the dynamic behaviors of automatic telescopic tail of AFC,the passivity-based?PB?analysis was performed.Combined with sliding-mode variable structure control?SMVSC?,the PB-SMVSC was established.Simulation results showed that the proposed control method has the good control tracking performance and robust.5)For investigation of realizing the intelligent control of the driving system,the meta-synthesis was used to establish the hall for workshop of meta-synthetic engineering?HWME?for the driving system of fully mechanized heavy AFC.And,a theoretical concept for the use of the mode was proposed,i.e.,the theoretical analysis and simulation evaluation system on intelligent driving system was initially established,which can be applied to the study of generic technology of conveying equipment.Such work can provide insights useful to realize intelligent driving.In summary,the work in this paper has further improved the basic theory of fully mechanized heavy armored face conveyor,and is of great significance in promoting the development of intelligent driving system for coal-based equipment.