Research On Dynamic Design And Control On Cone Dielectric Elastomer Actuator

Dielectric elastomer as a new type of electroactive polymer has attracted much attention in the field of flexible actuator design due to its characteristics of light weight,fast response,quiet operation,and high electromechanical conversion efficiency.Tapered dielectric elastomer actuators,as a thin film driver,can produce greater stress,strain,and power relative to planar film drivers.This paper focuses on tapered dielectric elastomer actuators,using theoretical derivation,numerical simulation,experimental analysis and other methods,and conducts research on multi-state driver design,self-sensing algorithm,and vibration control.The main contents are as follows:1.A method for adjusting the force balance of a nonlinear magnetic attraction is proposed.A driver with intrinsic three-steady-state property is designed and implemented,and the free switching between steady states is achieved by controlling the loading voltage.A super-elastic model of dielectric elastomer coupled to magnetic force was established,which revealed the intrinsic three-steady characteristics of the system and studied the changes of system potential energy under different influencing factors.The effects of parameters such as pre-stretching and actuator geometry on the steady-state number of the drive are discussed,and the characteristic parameter ranges of different steady states are given.By designing and fabricating a three-steady-state prototype,the three-steady-state characteristics and the steady-state switching mechanism of the driver were verified.The effects of magnetic force and steady-state jump on the performance of the driver were discussed.The multi-stable driver only needs to apply voltage during the steady state transition,and it can be powered off when the steady state is reached,avoiding the possibility of long-term power-on breakdown of the dielectric elastomer and reducing power consumption.2.A dielectric elastomer self-sensing algorithm driven by a physical model and data is proposed.The electrical model of the driver was established,and the simplification of the model under different parameters was discussed.The self-sensing current of the driver at different inputs was studied,and the correlation between DEA response displacement and self-sensing current was revealed.By designing the taper dielectric elastic self-sensing sensor,data such as current and displacement under different input excitations are collected.The relationship between self-sensing currents and response displacements was studied using a nonlinear input autoregressive neural network,and the effects of parameters such as hyperparameters on the prediction accuracy were analyzed.By increasing the number of training samples,the generalization ability of neural networks is improved,and good prediction results are also obtained on unknown signals.3.The vibration isolation effect of tapered dielectric elastomer shock absorber under base excitation was studied.Firstly,the dynamic model of the dielectric elastomer damper under mass loading was established by using the principle of virtual work.The passive vibration isolation effects of different damping,pre-tensioning,and mass dampers are discussed.The effects of pre-stretching,gravity and voltage loads on the equilibrium position of the isolator are studied.Based on this,the influence of voltage load on the natural frequency of the system is analyzed.A prototype of single-degree-of-freedom tapered dielectric damper was designed and fabricated.The transmission rate of shock absorbers under different harmonic excitation frequencies was studied,and the working range of passive isolation was obtained.The effects of different DC voltages on the natural frequency of the shock absorber were studied,and the frequency shift characteristics of the DE isolator under voltage load was verified.According to the electromechanical response characteristics of DE,a method of vibration isolation by adjusting the amplitude and phase of the input voltage load is proposed for harmonic pedestal excitation.For the sinusoidal base excitation,according to the electromechanical coupling characteristics of DE,the amplitude of the shock absorber at the natural frequency of the system is attenuated to 5.3% before isolation by adjusting the amplitude and phase of the voltage.