Improving Velocity of Stick-Slip Piezoelectric Actuators With Optimized Flexure Hinges Based on SIMP Method

Abstract

Flexure hinges have been widely applied in driving mechanisms to achieve the high velocity of stick-slip piezoelectric actuators. However, the majority of driving mechanisms are designed with existing flexure hinge forms, and it is difficult for the actuators to realize the optimal velocity performance. Therefore, a systematic method based on the topology optimization to design flexure hinges of driving mechanisms is proposed in this paper for improving the velocity of the actuators. According to the working principle, the velocity can be increased by maximizing displacement of a driving foot along the positive direction of x-axis. The optimization problem of flexure hinges is described utilizing the Solid Isotropic Material with Penalization (SIMP) method. To illustrate the proposed method in detail, a four-bar mechanism with optimized flexure hinges is designed. Among them, three optimization schemes are implemented based on positions of flexure hinge design domains, and then deformations and equivalent stresses of the four-bar mechanism are investigated by simulation to find optimal flexure hinge forms. To prove the feasibility of the proposed method, the characteristic experiments of prototype are conducted. When the driving voltage and driving frequency of prototype are 100 V p-p and 470 Hz, the maximum velocity is 17.50 mm/s, the maximum load is 220 g. And it is interesting to find that the prototype has no backward motion. Compared with the previously reported actuators with four-bar mechanisms, the velocity of prototype is significantly improved. INDEX TERMS stick-slip piezoelectric actuators, flexure hinges, driving mechanisms, SIMP method, velocity performance.

Piezoelectric stick-slip actuators with flexure hinge mechanisms: A review

“…Qiao et al (2021) simulated the transient dynamics on the stator, which proved that the driving arm of the designed FHMs-PSSA can produce deflection away from the rotor in the slip phase, see Figure 9(d). Besides, Yang et al (2020a) also used a topology optimization method combined with the FEM to optimize important structural parameters of the FHMs-PSSA.…”

“…(a) FHMs-PSSA with coupled asymmetrical flexure hinge mechanisms (Lu et al, 2020a), (b) FHMs-PSSA with series decoupling structure (Wang et al, 2019b), (c) FHMs-PSSA with centrally symmetric structure (Qin et al, 2019b), (d) Displacement curve of the FHMs-PSSAs under the excitation of the sawtooth waveform, (e) the FHMs-PSSA with the dual-mode excitation method (Ning et al, 2021), (f) Study on suppressing the backward motion by using the elastic restoring force of flexure hinge mechanism (Yang et al, 2020), (g) Research on the suppressing the backward motion by cooperative actuation of driving units (Fan et al, 2019), (h) Smooth motion type FHMs-PSSA with inertial block stricture (Qiao et al, 2021), and (i) Dual-servo control strategy for FHMs-PSSA (Li et al, 2017). …”

Topology Optimization Methods for Flexure Hinge Type Piezoelectric Actuators

“…Traditional researches have given some topological structure for the design of piezoelectric actuators [27][28][29][30][31][32][33][34], the not solved problem is that which kind of compliant mechanisms with the flexure hinges makes the output performances best. Yang et al [35] developed a static topology optimization method to solve the problem, and some topology optimization methods have also been extended to design the compliant mechanism of piezoelectric actuators [36][37][38][39][40]. At present, there is little research on using topology optimization method to design flexible hinges, and its theories and methods are very scarce, which has a lot of exploration space.…”