Research On Synchronous Control Of Rod Cylinder Drive System Of New Core Sampling Rig

In order to improve the efficiency and safety of core sampling rig,the research group designed an automatic full hydraulic core sampling drill that could realize rod feeding and rod fetching of two different diameters.In order to ensure its stable operation,this paper takes the automatic rod feeding mechanism of core sampling rig as the research object,and the main research content is as follows:(1)The electromechanical hydraulic system of the core sampling rig was established.Shubo X3623 A was used as the main controller of the core sampling rig.The drilling control program was written by Codesys software,and the one-key control software of the automatic rod feeding mechanism was written to improve the work efficiency.And established the mathematical model of rod cylinder drive system and completed the construction of the basic rig control platform.(2)The main nonlinear factors of rod cylinder drive system are the displacement and flow characteristics of valve core and load friction of electro-hydraulic proportional valve.Identification experiments were carried out,and the valve core displacement flow curve and load friction force were identified and fitted by least square method and genetic algorithm respectively.Finally,the steady-state accuracy of the two rod feeding cylinders is improved to 0.44 mm and 0.29 mm respectively by compensating the dead zone and using the load feedback proportional compensation for the nonlinear compensation control of the single cylinder.(3)In view of the multi-point synchronous control problem of rod feeding cylinder,I compared and determined the synchronization control scheme as cross coupling synchronous control,and finally took fuzzy PID cross coupling synchronous control with nonlinear compensation as the multi-point synchronous control scheme of rod feeding cylinder and carried out simulation.The results show that the maximum synchronization errors are 0.49 mm,0.68 mm,0.87 mm and 1.48 mm.The steady-state error,synchronous error and transport time all meet the control requirements of the rod feeding mechanism.(4)The driving system of rod cylinder drive system is tested on the experimental platform of core sampling rig,the effectiveness of nonlinear compensation scheme is verified,and the synchronous control scheme of two rod feeding cylinders is determined.Finally,the fuzzy PID crosscoupling synchronous control with nonlinear compensation is used to carry out multi-point synchronous control experiment of rod feeding cylinder.The actual maximum synchronous errors are 1.84 mm,2.18 mm,2.58 mm and 3.68 mm,respectively.The steady-state error,synchronization error and transport time all meet the control requirements of the rod feeding mechanism.This article has 98 figures,15 tables,71 references.