Development of a novel two-DOF piezo-driven fast steering mirror with high stiffness and good decoupling characteristic

A linear ultrasonic motor (USM) with two piezoelectric stators using the combination of two third bending vibration modes is proposed in this study, two orthogonal bending modes can simplify the effort of frequency degeneration. A square runner is driven by two stators through elliptical motions of their driving feet. Three driving feet in each stator are located at its middle and both ends, they vibrate with the same elliptical trajectory and push the runner together for improving the output performance. The finite element method (FEM) is adopted to optimize structural configuration of the stator, which ensures the amplitude uniformity of three driving feet. A prototype of the proposed USM is manufactured and its mechanical characteristics including velocity versus exciting voltage and velocity versus carrying load are tested in sequence. The tested results show that the maximum no-load velocity of the prototype is 117.22 mm/s at the exciting voltage of 65 Vp-p, and the maximum carrying load of the prototype is 350 g when the exciting voltage is 60 Vp-p. The tested results confirm that the developed USM has the advantages of simplified frequency degeneration in structure design and low exciting voltage.

Design and experiment of a three-feet linear ultrasonic motor using third bending hybrid modes

Design of a precise linear-rotary positioning stage for optical focusing based on the stick-slip mechanism

A compact inchworm piezoelectric actuator with high speed: Design, modeling, and experimental evaluation

A piezoelectric platform driven by a bionic quadruped piezoelectric actuator is developed. It uses the operating principle of combining bionic walking and swinging actuation modes to achieve nanopositioning in a large travel range. The mechanical structure is introduced, the operation principle is illustrated, and the dynamic model and control method are developed. The open-loop performances are first tested to verify the effectiveness of the operating principle and the dynamic model, and the simulation results agree well with the experimental results. Then, the closed-loop experiments in bionic walking and swinging actuation modes are carried out, respectively, and the controllers are designed based on the dynamic model. In the point-to-point positioning control experiments, the steady-state errors for the target position of ±1000  μ m in axes X and Y are within ±1  μ m in bionic walking actuation mode, and they are within ±20 nm for the target position of ±2  μ m in bionic swinging actuation mode. The closed-loop experiments under the combination of the bionic walking actuation mode and swinging actuation mode are performed, and a switched controller is developed to obtain the switching of the two modes automatically; the steady-state errors are within ±20 nm. The experimental results confirm that the method combining bionic walking and swinging actuation modes and switched control is valid in enhancing the positioning precision and travel range for the nanopositioning platform.

Development of a Nanopositioning Platform With Large Travel Range Based on Bionic Quadruped Piezoelectric Actuator

Arthropod-Metamerism-Inspired Resonant Piezoelectric Millirobot

A ring-shaped linear piezoelectric actuator with three driving teeth is proposed and designed based on an axial-radial bending coupling vibration mode. The coupling vibration mode is neither pure axial bending mode nor pure radial bending mode, but an axial-radial bending hybrid one, which is generated by only one group of PZT elements and one excitation signal under an asymmetric fixed boundary condition. The working principle of the proposed actuator is similar to the opening and closing actions of the three-petal mouth of a rabbit, which is analyzed by finite element method (FEM). Then, the coupling vibration mode is verified by a scanning laser Doppler vibrometer after the fabrication of a prototype. Experimental results show that the prototype can achieve a maximum velocity of 60.46 mm/s and a displacement resolution of 0.5 m, and the velocity of the linear actuator can be smoothly adjusted in a wide range of 0.00560.46 mm/s. In addition, the actuator can drive a hollow cylinder mover along different slopes without other auxiliary structures. The simulated and experimental results confirm that the proposed ring-shaped actuator is feasible without any guiding structure, which has great potential to realize further miniaturization of linear piezoelectric actuators.

A Linear Piezoelectric Actuator Based on Working Principle of Three-Petal Mouth of a Rabbit

Microactuators have been playing crucial roles in micromachine technologies because of their small sizes and light weights. The piezoelectric actuation is one of the most important driving methods to perform the motion output with miniature structures. The rotary piezoelectric microactuators are relatively mature, whereas the linear ones need to be further developed. Inspired by the hollowing art, a novel linear piezoelectric microactuator with miniature dimensions of 7.4 mm × 7.4 mm × 10 mm is proposed, which is designed to be an integrated hollow structure without a guide rail and can achieve bidirectional standing-wave drive. The bidirectional motions are achieved by the same first-order bending vibrations of two pairs of thin-walled beams, respectively, which are conducive to the consistency of the forward and backward motions indicate that the maximum velocity, resolution, and maximum thrust force achieved in the forward motion are 19.06 mm/s, 0.3 μm, and 17.45 mN, respectively, whereas those in the backward motion are 16.92 mm/s, 0.45 μm, and 15.28 mN, respectively. The design inspired by the hollowing art has the potential to be an effective and alternative solution for the development of linear piezoelectric microactuators.

Development of a Linear Piezoelectric Microactuator Inspired by the Hollowing Art

Multiple degrees of freedom (DOFs) motion manipulation of various objects is a crucial skill for robotic systems, which relies on various robotic hands. However, traditional robotic hands suffer from problems of low manipulation accuracy, poor electromagnetic compatibility and complex system due to limitations in structures, principles and transmissions. Here we present a direct-drive rigid piezo robotic hand (PRH) constructed on functional piezoelectric ceramic. Our PRH holds four piezo fingers and twelve motion DOFs. It achieves high adaptability motion manipulation of ten objects employing pre-planned functionalized hand gestures, manipulating plates to achieve 2L (linear) and 1R (rotary) motions, cylindrical objects to generate 1L and 1R motions and spherical objects to produce 3R motions. It holds promising prospects in constructing multi-DOF ultra-precision manipulation devices, and an integrated system of our PRH is developed to implement several applications. This work provides a new direction to develop robotic hand for multi-DOF motion manipulation from micro scale to macro scale. 

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Jing Li

Papers

Development of a Nanopositioning Platform With Large Travel Range Based on Bionic Quadruped Piezoelectric Actuator

Arthropod-Metamerism-Inspired Resonant Piezoelectric Millirobot

A Linear Piezoelectric Actuator Based on Working Principle of Three-Petal Mouth of a Rabbit

Development of a Linear Piezoelectric Microactuator Inspired by the Hollowing Art

Piezo robotic hand for motion manipulation from micro to macro