A novel fractional-order framework for creep nonlinearity in piezoelectric actuators

Due to their exceptional resolution, rapid response, and versatility, piezoelectric actuators (PEAs) find extensive application in high-end fields such as nano-positioning, semiconductor manufacturing, and space exploration. However, the nonlinear effects associated with creep significantly restrict the full performance potential of PEAs under extreme conditions. To address this limitation, we propose a fractional calculus-based model that effectively captures the multi-scale and complex dynamics of creep phenomena. This model incorporates only two unknown parameters, thereby simplifying the parameter identification process. Through comprehensive theoretical analysis, simulation, and experimental validation, our model has demonstrated considerable advantages in terms of accuracy and applicability, with relative error in both the frequency and time domains below 6 %. The proposed fractional creep model and its associated parameter identification technique are anticipated to enhance the long-term precision of PEAs, paving the way for future advancements in ultra-high-precision actuation technology.