The Research Of Whirling Motion And Piezoelectric Control Of BTA Deep-hole Drill Pipe System

With the rapid development of science and technology, the field of mechanicalprocessing is holding in a more and more important position. As an important way ofmachining, deep-hole processing technology has a pivotal position in the machinery industry.As the higher requirement of processing precision and efficiency, people begin to refineresearch contents, and BTA drill pipe system dynamics behavior is one of research contents.The whirling motion and eccentric control research of BTA drill pipe are the outstandingproblem of dynamic behavior, which affects the machining quality. This paper mainlyresearches the whirling motion and eccentric vibration control of BTA drill pipe, which hasimportant significance in the field of deep-hole machining.This paper mainly research and analyze around the whirling behaviour of the BTA deephole drill system as well as piezoelectric active control technology on the eccentricityvibration of the pipe. Based on rotor dynamics theory and using the solid-liquid couplingprinciple, the paper research on complex whirling motion behavior theory of BTA drill pipesystems coupled with the vibration. The paper research occurrence conditions and forms andthe reason of instability of the whirling, and put forward a solution for various influencefactors. Because the whirling is an eccentric motion, we must control the range value of theeccentric so that it does not affect the quality of machining. This paper puts forward a methodindependent modal control based on linear quadratic regulator(LQR), a piezoelectric activecontrol method, deduce the piezoelectric BTA drill pipe theory and structure modeling, andmake control simulation by MATLAB. Lastly, make control simulation analysis on the finiteelement model of the BTA deep hole drill pipe and piezoelectric vibrator by ANSYS, andmake control simulation on the piezoelectric BTA drill pipe by the two order differencemethod.This paper firstly analyzes the dynamics behavior features of BTA drill pipe system, which provide theoretical basis for the whirling research of drill pipe system. Then get thetheoretical trajectory of drill pipe whirling, movement forms and its inherent characteristicsby its feature similar to flexible rotor motion mechanics structure. BTA drill pipe whirlingregularity are obtained through deducing the generation condition of the whirling moton ofthe drill pipe system, the critical speed of the whirling and the whirling frequency thresholdpoint of unstability. Lastly, the paper make a simulation about piezoelectric active controlmodel based on LQR independent modal control theory combinined with BTA drill pipesystem structure, which analyzes properties of piezoelectric sensor and actuator. MATLABsimulation of LQR optimal control is realized under the weight matrix Q and R configured,which verify LQR optimal control effectively. The transient dynamics simulation on ANSYSverifies the feasibility of the piezoelectric control. All the above research results provid atheoretical basis for the research of the movement behavior of BTA drill pipe and a referencefor drill pipe whirling and the control of eccentric vibration.