Research On A Piezoelectric Stack Sensing Actuator Based On Resonant Sensing

With the in-depth research and development of piezoelectric materials,it bounds to be a major tendency to use the piezoelectric materials to realize the integration of the piezoelectric actuators and piezoelectric sensors in the future.In the field of piezoelectric research,piezoelectric ceramics are widely used for research and production of piezoelectric actuator because of its superiority of high piezoelectric constant,good stability and fast response.On the other hand,quartz crystals are commonly used in the study and application of high precision sensor due to their high mechanical strength,good linearity and resolution.Therefore,taking into account combining the advantages of two kinds of piezoelectric materials,this paper developed and studied a piezoelectric stack sensing actuator based on resonant sensing through theoretical research,simulation analysis and experimental verification,which can output and measure force and displacement simultaneously.It is mainly be geared to the needs of intel igent measurement and control field of electromechanical system.Furthermore,the force-frequency characteristics of the sensor were analyzed under different driving conditions to explore the application scope of this kind of structures.Firstly,piezoelectric ceramics and quartz crystals were taken into research and employed as the actuator and the sensor in this paper.Based on the basic theory of piezoelectric materials,the structure and encapsulation design of the piezoelectric stack sensing actuator based on resonant sensing were completed.Besides,this paper built the analytical model of piezoelectric stack and obtained the basic detection mechanism of quartz crystals.Secondly,the finite element analysis model was established to carry out the finite element simulation analysis of piezoelectric stack sensor actuator in ANSYS.The frequency characteristic analysis of quartz crystal oscillator were analyzed at different radius and thickness of electrode structure.As a result,the influence of the electrode structure parameters on the resonant frequency and vibration mode of quartz crystal oscillator were obtained and the curves of force-frequency characteristics were subsequently acquired.Then the frequency characteristic as well as dynamic simulation analysis of the whole model was carried out to determine the basic working conditions and the output displacement response characteristics.The oscillation and difference-frequency circuit of the sensor part were also designed in this paper.Afterwards,the rationality and feasibility of the circuit was verified by circuit simulation in Multisim.Finally,the piezoelectric sensor actuator prototype was fabricated and the experimental system was built.The LabVIEW software was used to record and process the experimental signals to measure and analyze the displacement output characteristics of piezoelectric stack sensing actuator under different excitation signals.And on this basis,the force-frequency characteristic of the sensor part was studied experimentally by changing the working conditions of the actuator.The prerequisite for the model to work was discussed.The correctness of the theory as well as simulation analysis were verified by comparing the experiments and simulation results.