To mitigate electromagnetic transient impacts on the power grid during circuit opening and closing operations, precise phase control necessitates exceptional consistency in the operating time of fast mechanical switches driven by ultrasonic motors. However, mechanical clearance and collision introduce significant dispersion in operating time. Moreover, because the operating time lies on the millisecond scale, conventional closed-loop control methods face prohibitively complex implementation challenges. To address this issue, this study develops an analytical model of the fast mechanical switch driven by an ultrasonic motor and proposes a Support Vector Regression (SVR)-based prediction model to characterize and compensate for operating time dispersion via a delayed-start strategy. The analytical model provides the theoretical operating time and identifies key working parameters. The SVR-based prediction model then estimates the actual operating time. The required delayed-start time corresponds to the difference between the theoretical and predicted operating times. Unlike traditional closed-loop control, which demands high-frequency sampling and real-time computation of control laws, the proposed method only requires offline prediction of operating time based on observed data, followed by determination of the delayed-start interval. Experimental results demonstrate that this approach controls operating times within 23 ± 0.15 and 25 ± 0.15 ms, satisfying the phase control requirements for the fast mechanical switch. This performance surpasses the current operating time dispersion control of ±0.2 ms achieved in Thomson-coil-driven mechanical switches.

In response to the requirements of high precision alignment and focusing and high dynamic adjustment in complex optical measurement systems, a dynamic model of an optical adjustment component driven by a double-bend mode coupled ultrasonic motor is established, and a fast control method for stabilized positioning of the optical adjustment component based on input shaper is proposed. Firstly, the structure design of an optical adjustment component driven by an ultrasonic motor(USM) is introduced. Secondly, the dynamic model of the optical adjustment component driven by an USM is constructed. Based on Hamilton's principle, an electromechanical coupling model of the USM is proposed. According to the Hertz theory, a contact friction model including the fixed mover and the optical adjustment component is established. Thirdly, relying on the system's dynamic model, a micro-step control method for USM input pulse shaping is proposed to achieve fast control for stabilized positioning, and realize the fine and stable motion of the adjustment component. Finally, a prototype was prepared for experimental testing to verify the method's effectiveness. The vibration equation and output characteristics of the system model are consistent with the experiment. The experimental results show that the system achieves a positioning error of under 1 mu m over 500 mu m movement, demonstrating the control method's efficacy. With Zero Vibration and Derivative input shaping, the control method reduces stabilization time required for directional motion of the system by 83 %, which meets fast and high-precision positioning requirements of the complex optical system for the optical adjustment component.

Focusing mechanisms are critical components of optical systems, such as airborne remote sensing, deep space exploration, and biomedical engineering. Traditional focusing mechanisms driven by electromagnetic motors or piezoelectric stack actuators struggle to achieve high resolution, fast response speed, and long stroke simultaneously, falling short of meeting the requirements for high-resolution and high-speed imaging mainly because electromagnetic motors have poor precision and piezoelectric stack actuators have limited stroke. To address these challenges, this study proposes a novel flexible focusing mechanism driven by an ultrasonic motor, integrating a double-bending mode ultrasonic motor with a long-stroke flexible mechanism. First, a compact doublebending mode ultrasonic motor is designed and optimized to accommodate limited vertical space. The design prioritizes a reduced height while maintaining stable performance. Second, based on the pseudo-rigid-body model, the parametric and structural design of the flexible mechanism is completed using a hybrid configuration that incorporates a parallelogram flexible mechanism. Third, the dynamic model of the moving platform is established. Through simulation, it is observed that driving the flexible mechanism improves stability by 83.34 % compared to a rigid body. This helps to improve the accuracy of the focusing mechanism. A prototype of the focusing mechanism is fabricated and tested. The experimental results show that the focusing mechanism's response time, resolution, and stroke are 40 ms, 90 nm, and +/- 5 mm. The proposed focusing mechanism demonstrates the capability of nanometer-scale focusing with nanometer precision in a millimeter stroke.

With the diversification and multifunctionality of space missions, micro-nano satellites need to carry more payloads in deep space orbits with harsh lighting conditions. Traditional built-in batteries and fixed deployable solar wings offer limited energy, making it difficult to meet these demands. Although solar wing drive mechanisms powered by stepper motors and harmonic reducers improve power output, their large size, weight, and complexity render them unsuitable for micro-nano satellites. This paper presents a solar array drive assembly driven by an ultrasonic motor, designed for micro-nano satellites operating in the halo orbit at the Lagrange L2 point of the Earth-Moon system. This design addresses the need for miniaturization and lightweight construction while enhancing energy supply. Key components, including the yaw axis pointing mechanism, solar panel assembly, angular displacement detection, energy transmission system, and ultrasonic motor, are optimized for size and weight reduction. To identify the optimal energy-saving drive method, a dynamic model of the SADA system is established, and a novel low-power driving method for the ultrasonic motor-driven solar wing is proposed. A prototype with a volume of less than 0.5U and a mass under 0.2 kg was fabricated. Experimental results show that the output torque of the ultrasonic motor exceeds 0.0581 N m, with the number of driving signal cycles n positively correlated with the total rotation angle theta of the solar wing. When n =1000 and the interval time Tm = 1.35 h, the mechanism achieves its lowest energy consumption cost, allowing the solar wing to operate at 12.1 degrees per day, saving over 23.8 % of energy compared to continuous drive methods.

The pointing mechanism is a very common mechanical device and has a wide applications in the aerospace field. Most of the traditional pointing mechanisms are driven by electromagnetic motors and hydraulics, which make it difficult to meet the demands of high precision and customization. In this paper, a ball-cage structure piezoelectric actuator is proposed for the spherical 2-DOF pointing mechanism, which to switch the direction of the degrees of freedom by changing the excitation mode. Through the machining of the prototype and experimental analysis, the prototype can reach a speed of 533 deg/s and has a resolution of 42 μrad, which can meet the demand of high-precision application of pointing mechanism.

As the output voltage amplitude and frequency of the non-isolated ultrasonic motor drive circuit increase, the common-mode voltage issue of the ultrasonic motor becomes more prominent, severely affecting the system’s operating accuracy and efficiency. This paper conducts research on the V-shaped ultrasonic motor, analyzing the mechanism of common-mode voltage generation and the electrical model. It summarizes methods to reduce common-mode voltage, providing a theoretical basis for optimizing the structure design and assembly dimensions of ultrasonic motors. Finally, the proposed model is verified through simulations, proving the accuracy of the presented theory.

Piezoelectric actuators are extensively used in aerospace and precision instruments due to their high precision and simple structure. However, conventional piezoelectric actuators intended for multi-degree-of-freedom (multi-DOF) motion typically have high mass and low space utilization due to their complex structures. This makes them unsuitable for use in the joints of lightweight robots. To address these issues, we propose a novel one-piece multi-DOF piezoelectric actuator. This actuator can achieve multi-DOF motions with the mover such as flat plates or spherical shells. Through finite element simulation analysis, we determined the primary dimensional parameters of the stator. We then fabricated an experimental prototype with dimensions of approximately Phi 40 x 3 mm, weighing about 23.5g. Experimental results indicate that the prototype achieves a maximum rotary motion speed of 5.03 rad/s and a maximum linear motion speed of 9.17 mm/s, with a maximum load capacity of 50g. The actuator exhibits a minimum rotary motion resolution of 18 mu rad and a minimum linear motion resolution of 2 mu m. This study demonstrates that such multi-DOF actuators have great potential in areas such as small and lightweight precision robots due to their compact structure, small volume, light weight, and high precision.

Piezoelectric actuators based on non-metallic materials have drawn much attention in recent years. Carbon fiber reinforced plastic (CFRP) is one of the ideal materials for the development of lightweight, high power density piezoelectric actuators because of its low density, high stiffness. However, its anisotropic characteristics pose a challenge in actuator development. In this study, we designed a CFRP-based piezoelectric actuator, which utilizes hybrid modes of first-order longitudinal mode and second-order bending mode. The electromechanical coupling dynamic model for CFRP-based piezoelectric actuator was established a, based on the modal superposition method and energy method, and while taking into account the stress-strain relationships in anisotropic materials. The size of the actuator was calculated through the model and a prototype was processed for experimental research. The experimentally obtained results of frequencies and transient- as well as steady-state vibration characteristics demonstrated excellent agreement with the predictions of our mathematical modeling. Actuator performance evaluation results show that under a single-phase excitation voltage of 200 Vp-p, the CFRP-based actuator can reach maximum speed, thrust force, output power, thrust-weight ratio, power density, and efficiency of 617 mm s-1, 65 N, 1.14 W, 980.3 N kg-1, 223.5 W kg-1, and 10.4%, respectively. These results are satisfactory compared with actuators in other reports, especially the power density, which is nearly tripled. These results demonstrate the superior performance of the CFRP-based actuator and illustrate a new approach for developing lightweight and powerful actuators.

Space pointing mechanisms are crucial for controlling the movement of solar arrays, which can significantly improve power generation. So the solar array drive assembly plays a key role in advancing space technology. However, most current solar array drive assemblies face challenges related to weight and size. Therefore, this paper presents a lightweight design solution: a solar array drive assembly powered by ultrasonic motors that meet the requirements for the lightweight design. Firstly, a coordinate transformation in geosynchronous orbit is established to analyze the design requirement of the mechanism’s degree of freedom. Next, the structural composition and working principle of the mechanism is introduced. To achieve precise pointing motion, forward and inverse kinematic models are developed, followed by an analysis of the mechanism’s workspace and error model. The solar array drive assembly proposed in this paper is expected to be applied in micro-satellites and special orbiting spacecraft in the future.

The robotic arm has the characteristics of multi-degree-of-freedom motion and can perform complex tasks, making it the first choice to replace manual operations in space environment. However, traditional robotic arms still face many challenges in achieving both lightweight and high precision. To overcome this, we present an integrated stator -rotor piezoelectric actuator that integrates structural and functional design, enabling substantial weight reduction and high motion accuracy. The proposed design meets the requirements of the aerospace field, making it an ideal replacement for manual operations in space. The mechanism is composed of two sets of orthogonally linked rotary joints with driven arm joints enabling rotation in two vertical directions. To reduce the impact of clamping on vibration characteristics, the vibration modes and structural parameters are optimized through simulation. The size of the fabricated prototype is 160 x 60 x 60 mm, and its weight is only 24 g. The experimental results show that the maximum motion speed of the mechanism is 620 deg/s and the stalling torque is 20 mN m at 300 Vpp. The minimum resolution can reach 25 mu rad in pulse mode, and a startup and shutdown response time of 45 ms and 31 ms at 200 Vpp, respectively. These characteristics verify the correctness of the design and show that the actuator has tremendous application potential.

Microneedles (MNs) are particularly attractive for transdermal administration because of the improved safety, patient compliance and convenience. Dissolving MNs could provide rapid transdermal delivery, but with relatively low mechanical strength and almost no sustainability. On the other hand, hydrogel MNs are complicated to fabricate and have risk concerns. Herein, we developed a biodegradable MNs array composed of biocompatible silk fibroin and poly(vinyl alcohol) to overcome these limitations. Finite element analysis was employed for parameter optimization. The MNs array fabricated by the optimal parameters and material displayed sufficient mechanical strength to disrupt stratum corneum and formed microchannels for transdermal delivery. Dual-release profile was observed in the MNs array, with rapid release in the beginning, and prolonged release afterward. This release behavior fits Weibull release model and is favorable for topical application. The initial immediate release can quickly deliver active compounds to reach the therapeutic effective concentration and facilitate skin penetration, and the sustained release may supply the skin with active compounds over a prolonged period. This biodegradable MNs array is easy to fabricate, mechanically robust, could eliminate safety concerns, and provide the sustainability and advantage for large-scale production.

Intravascular optical coherence tomography (IV-OCT) is crucial for evaluating lumen dimensions and guiding interventional procedures. However, traditional catheter-based IV-OCT faces challenges in achieving precise and full-field 360° imaging in tortuous vessels. Current IV-OCT catheters that employ proximal actuators and torque coils are susceptible to non-uniform rotational distortion (NURD) in tortuous vessels, while distal micromotor-driven catheters struggle with complete 360° imaging due to wiring artifacts. In this study, we developed a miniature optical scanning probe with an integrated piezoelectric-driven fiber optic slip ring (FOSR) to facilitate smooth navigation and precise imaging within tortuous vessels. The FOSR features a coil spring-wrapped optical lens serving as a rotor, enabling efficient 360° optical scanning. The structurally-and-functionally-integrated design significantly streamlines the probe (with a diameter of 0.85 mm and a length of 7 mm) while maintaining an excellent rotational speed of 10,000 rpm. High-precision 3D printing technology ensures accurate optical alignment of the fiber and lens inside the FOSR, with a maximum insertion loss variation of 2.67 dB during probe rotation. Finally, a vascular model demonstrated smooth probe insertion into the carotid artery, and imaging of oak leaf, metal rod phantoms, and ex vivo porcine vessels verified its capabilities for precise optical scanning, comprehensive 360° imaging, and artifact elimination. The FOSR probe exhibits small size, rapid rotation, and optical precision scanning, rendering it exceptionally promising for cutting-edge intravascular optical imaging techniques.

Traveling wave rotary ultrasonic motors (TRUMs) are widely used in various industrial processes due to their attractive features, such as compact structure, high accuracy, and fast response. However, the major limiting factors of the operational performance of TRUMs under high-voltage excitation are the nonlinear behavior caused by the nonlinearities of the piezoelectric materials and the friction between the stator and rotor of the motor. In this study, a nonlinear dynamics model and an identification method are presented to directly design the driver circuit for suppressing the nonlinear behavior under high voltage excitation. Firstly, by studying the time–frequency characteristics of the isolated electrode voltage, a single-sided Hertzian contact forced oscillator model of TRUMs is established, involving the nonlinearities of the piezoelectric material and friction. Secondly, a harmonic balance nonlinear identification is proposed in the time domain for TRUMs. The influence of the voltage and preload on the nonlinear phenomena is discussed. Lastly, a novel driver circuit is proposed to suppress the nonlinearities using feedback from the isolated electrode. Experiments showed that the total harmonic distortion decreased by 89.4% under 500 Vpp. The proposed drive circuit design method is used to find a high excitation voltage and preload to achieve greater motor output power.

Piezo-driven resonant fiber optic scanners are gaining more and more attention due to their simple structure, weak electromagnetic radiation, and non-friction loss. Conventional piezo-driven resonant fiber optic scanners typically use quadrature piezoelectric tubes (piezo tubes) operating in 31-mode with high drive voltage and low excitation efficiency. In order to solve the abovementioned problem, a resonant fiber scanner driven by co-fired multilayer piezoelectric ceramics (CMPCs) is proposed in which four CMPCs drive a cantilevered fiber optic in the first-order bending mode to achieve efficient and fast space-filling scanning. In this paper, the cantilever beam vibration model with base displacement excitation was derived to provide a theoretical basis for the design of the fiber optic scanner. The finite element method was used to guide the dynamic design of the scanner. Finally, the dynamics characteristics and scanning trajectory of the prepared scanner prototype were tested and compared with the theoretical and simulation calculation results. Experimental results showed that the scanner can achieve three types of space-filling scanning: spiral, Lissajous, and propeller. Compared with the structure using piezo tubes, the designed scanner achieved the same scanning range with smaller axial dimensions, lower drive voltage, and higher efficiency. The scanner can achieve a free end displacement of 10 mm in both horizontal and vertical directions under a sinusoidal excitation signal of 50 Vp-p and 200 Hz. The theoretical, simulation and experimental results validate the feasibility of the proposed scanner structure and provide new ideas for the design of resonant fiber optic scanners.

The tail rotor of a helicopter, a crucial component, traditionally relies on a complex drive mode involving reducers and transmission gears. This conventional setup, with its lengthy transmission chain and numerous components, hinders miniaturization efforts. In response to this challenge, our paper presents a novel piezoelectric drive approach. Our objective was to suggest an innovative design capable of minimizing the components involved in the tail rotor drive. This design can be adjusted in size according to specific requirements and is effective up to a specified speed. Moreover, it facilitates the process of miniaturization and integration. The piezoelectric actuator's stator comprises an ultrasonic amplitude transformer, a ring, and three drive teeth. Utilizing the rod-like structure of the tail brace, the actuator is simplified by adhering ceramic sheets to it. The rotary piezoelectric actuator combines the first longitudinal mode of a rod with torus bending modes. The drive teeth then amplify the ring's displacement, facilitating rotor rotation. The resonant frequency and modal shape of the actuator were determined using the finite element method. Furthermore, an investigation was conducted to analyze the influence of the drive teeth positioning on the motion trajectory at the contact point. Theoretically, we infer that the declination angle of the drive tooth is a crucial parameter for achieving high speeds. To test our idea, we built three prototype stators with different drive tooth declination angles. Our actuator stands out for its cost-effectiveness, structural simplicity, compatibility with harmonic signals, and ease of miniaturization. It can be considered for the drive of the tail rotor of a microhelicopter.

Piezoelectric rotary actuators are widely used for their high precision and large torque in various fields, such as optical engineering and aerospace. However, traditional piezoelectric rotary motors have a complex structure, requiring separate stator and rotor fixing devices, and they have a low space utilization rate, making them unsuitable for driving joint rotation of robotic arms. To address these issues, a novel stator-rotor integrated piezoelectric actuator is proposed in this paper, which uses the piezoelectric vibrator as both the driving vibration source and the rotor, simplifying the overall structure of the rotary actuator. By using in-plane longitudinal and out-of-plane bending vibration, the actuator achieves high-precision rotation along the diameter of a circular ring, while also providing a hollow structure for optical fibers and wires. Through parametric scanning finite element analysis, the size parameters of the annular rotor are determined. The contact conditions of stator and rotor is analyzed, and an intermittent contact model between stator and rotor is established. The experimental results show that the prototype motor weighs 52 g, has a rotation speed of 1470 deg/s, can bear a load of 63 mN m, and has a minimum resolution of 72 grad. This research demonstrates the great potential of this rotating actuator for use in space optical instruments and aerospace applications.

Drilling extra-terrestrial planets can be difficult, which is restrained by the payloads, power, and requirements of low axial force of rover posed by low environmental gravity, and drill bits can be trapped at a large depth, due to the accumulated spoils resulted from the low efficiency removal rate. This can cause motor to stall and draw excessive power. This work explores the opportunity of superposition of ultrasonic vibration on a vertical rotating auger in a variety of granular media. Ultrasonic vibration is known to facilitate direct penetration of granular materials, and it is anticipated that any related reduction in the contact friction force might improve augering performance. Experimental results suggest that, compared to the non-ultrasonic scenario, ultrasonically assisted augering process has significantly promoted the flow of granular media and has moderately reduced the torque required to operate the device. Furthermore, it was discovered that particle size and auger speed also affect the performance of the auger system in different ways as the ultrasonic amplitude is adjusted.

This paper explores the superposition of ultrasonic vibration on vertical rotating augers in a variety of granular media. Ultrasonic vibration is known to facilitate direct penetration of granular media, and it is anticipated that any related reduction in the torque requirements of a rotating system might improve augering performance. Experimental results suggest that, compared to the non-ultrasonic scenario, ultrasonically assisted augering significantly promotes the flow of granular media, while moderately reducing the torque required to operate the device. Furthermore, it was discovered that particle size, helix angle, and auger speed all affect the performance of the auger in different ways as the ultrasonic amplitude is adjusted.

随着新材料、新技术、新结构形式的出现,超声电机的结构和性能逐渐得到改善.因此,该技术的应用范围也在不断扩大,特别是在生物医疗领域.本文综述了超声电机在生物医疗领域的应用和发展趋势,对超声电机的应用现状和前沿研究进展进行了总结和分类,包括在磁共振成像、内窥镜及智能眼镜等医疗仪器方面的应用.最后,展望了未来的研究方向和前景.

With the diversification of the CubeSat exploration mission, it is urgent to develop the Ka-band mesh reflector antenna deployable mechanism for the farther the communication distance between the stars and earth. However, current drive devices based on electromagnetic motors, pyrotechnics and elastic deformation energy cannot meet the volume, weight and power consumption requirements of the CubeSat. Therefore, a noble antenna deployable mechanism which use the dual-bend mode coupled type piezoelectric actuator as the drive devices is designed, and the truss structure consisting of 1 moving pair and 12 rotating pairs. Through finite element method, the body and face folding ratio of the antenna deployable mechanism are 206.10 and 205.44 respectively. Experiment proves that the best working frequency of the piezoelectric actuator is between 19.21 kHz and 19.24 kHz and piezoelectric actuator can drive the truss structure unfolding from the folded state in the preset position in 10 seconds.