Cantilever Beam Deformation Control Based On Self-sensing Execution Technology

Since the Wright brothers invented the first aircraft,people have been working on designing an aircraft that can fly like birds.With the development of technology,the concept of "morphing aircraft" has gradually gained the attention of scholars at home and abroad.The morphing aircraft can adjust the wing shape according to the flight environment and purpose,so that it can autonomously change the aerodynamic characteristics to maintain the optimal wing load.The early morphing aircraft deformation was achieved by mechanical devices,but now,it is manipulated by smart materials instead of cumbersome mechanical structures.The main problem of practice application of the deformation control technology is whether the independent deformation and precise control of the wing can be realized.Based on this,the self-sensing deformation control by using the cantilever beam as the scale model of the wing is studied in this paper.The major control object is flexible cantilever beam,and the system driver is made of Macro Fiber Composite(MFC).Piezoelectric cantilever beam system has problems such as electromechanical coupling and hysteresis nonlinearity,which hinders the construction of the model.Moreover,the system deformation monitoring of piezoelectric cantilever beam mostly relies on external sensors.However,in practical applications,due to air flow,noise and other factors,the measurement error of the sensing process is large,which challenges the design of the sensors and the controllers.This paper analyzes the positive and inverse piezoelectric effect of piezoelectric material,and establishes a dual-port network according to the theory of bi-directional transducers.Then a scheme of using two pieces of MFC is proposed.The two MFC act as the sensor and actuator,respectively.Based on the characteristics analysis of the cantilever beam system,the Modified Prandtl-Ishlinskii model is used to perform the identification of the hysteresis system,and the identified hysteresis system is utilized to solve the nonlinear problem of system modeling and realize the linearization of the static system.Aiming at the problem of designing a piezoelectric cantilever beam system controller,first,the ARMAX model is used to identify the system transfer function,and then the incremental PID controller is used as the system deformation controller.The PID parameters are optimized by typical intelligent algorithm at this present stage,what’s more,the performance curves of the response curves are compared and analyzed.Finally,a compound particle swarm optimization algorithm is proposed to optimize the PID controller parameters.The optimized system can achieve fast response speed and effectively improve the control efficiency.The hysteresis model and transfer function of the system are identified on the MATLAB/Simulink platform,what’s more,a large number of numerical simulations are carried out to verify the effectiveness of the self-sensing process.The hardware platform of the piezoelectric cantilever beam system is built.The LabVIEW software is used as the human-computer interaction platform.The open-loop hysteresis inverse compensation,self-sensing actuator and compound particle swarm optimization control algorithm are combined to design a closed-loop controller.The experimental results show that the displacement of the piezoelectric cantilever beam system can be characterized linearly by the voltage output of the sensor MFC,so that the sensing function can be realized.Finally,driving the actuator MFC can realize the self-sensing deformation control.The optimized controller has a fast response speed,the rise time is 0.12 s,the adjustment time reaches 0.32 s,overshoot is 1.72%,and the steady-state tracking error is within 5%.