Design And Experimental Study Of An Ultrasonic/Sonic Driller Using Single Crystal Piezoelectric Ceramics

Asteroid exploration is one of the hotspots of deep space exploration.It has farreaching significance for the development of space resources,the construction of asteroid early warning defense system,the exploration of the formation of the solar system and the origin of life on Earth.Ultrasonic drillers based on piezoelectric drive principle have the characteristics of low weight on bit,small volume and low power consumption,so they have significant advantages in the field of asteroid detection.In this paper,the design,temperature characteristics and temperature adaptation of an ultrasonic driller using single crystal piezoelectric ceramics are carried out by means of theoretical analysis,simulation and experimental study.The driving characteristics of piezoelectric transducer were studied.Based on the differential motion equations for the elastic body,the wave equation of the piezoelectric transducer is established,and size parameters of the transducer are determined.The modal analysis and harmonic analysis of the piezoelectric transducer are carried out by finite element method(FEM).The influence of pre-tightening moment on output characteristics of the piezoelectric transducer is studied by means of impedance analyzer and laser displacement sensor;Impedance matching of the piezoelectric transducer is carried out to reduce its reactive loss.The temperature characteristics of the ultrasonic transducer were studied.Based on FEM,the temperature rise model of the piezoelectric transducer is established,and the temperature rise of each key part is obtained.Based on the temperature rise analysis,the frequency drift characteristics of the piezoelectric transducer are studied by using pre-stressed modal analysis.The temperature-frequency characteristics of the piezoelectric transducer is studied by simulation analysis.The finite element method is used to analyze the pre-stress distribution of the piezoelectric ceramic stacks under different ambient temperatures.An ultrasonic driller using single crystal piezoelectric ceramics is developed.To study temperature adaptation of the ultrasonic driller,an experimental system for high and low temperature driving characteristics testing of the ultrasonic driller was developed.The experimental system can provide high and low temperature environment,monitor parameters such as weight on bit and drilling speed.The system is used to carry out experimental research on drilling performance of the ultrasonic driller.Several drilling tests are carried out to analyze the relations between weight on bit,power and drilling speed;Experimental studies are carried out to analyze drilling speed of the driller to rocks with different hardness and drill-ability grade;Experimental research on high and low temperature adaptation of the ultrasonic driller is carried out.