Study On Micro Injection Pump Driven By Giant Magnetostriction And Its Control System

The driving element is the core element of micro-injection pump,and its output performance and control precision directly affect the infusion performance of micro-injection pump.At present,with the progress of society and the development of science and technology,the major hospitals and scientific research colleges and universities of microinjection pump infusion precision and control requirements are more and more high.The existing micro injection pump mainly uses the injection mode powered by stepper motor as the driving source,which has certain defects in clinical injection control and precision,and can not meet the requirements of current medical units.In view of the above problems,this paper analyzes and studies the design and working mode of micro injection pump by domestic and foreign injection medical device enterprises and relevant scholars.By comparing and analyzing the performance differences of three driving modes used in micro injection pump(namely,stepper motor drive,piezoelectric drive,magnetostrictive actuator),Based on giant magnetostrictive actuator(GMA),a micro-flow driving device for micro injection pump was designed.The driving device mainly includes giant magnetostrictive actuator and displacement amplification mechanism.Finite element analysis software is used to simulate the driving device,and the control system and test platform are built,and its performance is tested and analyzed.In this paper,the structural parameters of GMA,driving magnetic field,bias magnetic field,heat dissipation device,precompression force device and so on are designed,and according to the requirements of micro injection pump and the problem of insufficient output displacement of GMA,the displacement amplification mechanism is designed.Based on the design of the giant magnetostrictive microdrive device and displacement amplification mechanism,the finite element simulation analysis and experimental testing methods were used to study and analyze the results show that: The design of GMA meets the application requirements without any magnetic leakage phenomenon.At the same time,it is found that when the excitation current is 0.5～1.5A and the precompression force is 300 N,the current has a good linear relationship with the output displacement.The theoretical amplification ratio of the amplifier is 5.38%,the simulation result is 5.33%,the experimental test result is 5.23%,and the error value is 2.8%.The strength of the structure is far lower than its allowable stress,which meets the application requirements.Aiming at the control problem of micro-injection pump,the control system model of GMA is established,and the simulation analysis is carried out.The results show that the control system is stable,and the adjustment time and overshoot are greatly improved compared with that before parameter setting.Finally,the experimental test platform of GMA control system was built and the designed control system was tested.The results show that the adjustment time and peak time of the control system are slightly longer than the simulation results,but the overall performance of the control system is good in the time domain index.The research of this project provides theoretical and experimental basis for the theoretical and experimental research of micro injection pump driven by giant magnetostretchable microform.