The traditional stick-slip piezoelectric actuator uses a single flexible hinge structure, and the output force of the piezoelectric stack is greater than the clamping force between the driving foot and the slider, resulting in a small working stroke, slow speed, and poor load capacity. A new piezoelectric actuator based on a two-stage flexible hinge structure is proposed. The piezoelectric actuator uses a combination of a lever flexible hinge and a triangular flexible hinge. The working stroke and speed of the actuator are enlarged by the lever flexible hinge, and the output force of the piezoelectric stack is perpendicular to and greater than the clamping force between the driving foot and the slider through the triangular flexible hinge, which enhances the load capacity of the actuator. First, the structure and working principle of the piezoelectric actuator are presented. The lateral output displacement of the piezoelectric ceramic stack is amplified by the lever amplification structure so that the triangular flexible hinge structure is then used to convert the lateral displacement into a coupled motion composed of longitudinal and lateral displacement to drive the slide rail to generate total displacement. Then, the superiority of the piezoelectric actuator was verified through the analysis of displacement amplification and clamping force and finite element analysis. Finally, the performance of the piezoelectric actuator is studied. It can produce an output speed of 354.55 mm/s under a driving voltage of 4.7 kHz and 150 V, and the maximum load can reach 3 kg. This article provides a new design idea for stick-slip piezoelectric actuators.
Active vibration control of an axially translating robot arm with rotating-prismatic joint using self-sensing actuator is investigated. The equations of the system are derived by Lagrange's equation with the assumed mode method. The displacement and velocity control law is used to configure the self-sensing actuator, which provides the active damping and stiffness effect to the structure. The numerical simulations reveal that the tip deflection of the arm can be effectively reduced by the self-sensing actuator. The amplitude of sensor voltage is inversely proportional to the length of axially translating arm. And higher feedback control gain results in lower sensor voltages and vibration amplitudes.
A novel piezoelectric actuator using a two-stage flexure hinge structure is proposed in this paper, which is used in a compact and high-precision electromechanical field. The two-stage flexure hinge structure is used to provide horizontal thrust and vertical clamping force to the driving feet, which solves the problems of unstable clamping force and insufficient load capacity in traditional stick-slip piezoelectric actuators. Firstly, the main structure of the driver and the working process under the triangular wave excitation voltage are briefly introduced. Secondly, after many simulation tests, the structure of the actuator is optimized and the stability of the structure in providing clamping force is verified. Finally, through the research of the operating performance, when the amplitude is 150 V and the frequency is 3.25 kHz as the excitation source, the maximum speed can reach 338 mm/s and can bear about 3 kg load. It can be seen from the analysis that the two-stage flexure hinge structure can improve the displacement trajectory.
This paper proposes a new research method in view of the rare research on the contact state of hybrid drive multi-degree-of-freedom motor. Firstly, the basic principle and structure of hybrid drive motor are introduced. The air gap magnetic field model and electromagnetic torque model of permanent magnet rotor are obtained by analytical method. Static analysis of piezoelectric stators are carried out by stress-strain relationship. According to the analytical method and the spatial geometric relationship, the piezoelectric driving torque under different driving conditions is obtained. Introducing Hertz contact theory and Mindlin theory, combined with piezoelectric driving torque, electromagnetic driving torque and load torque to analyze the friction situation. A friction interface model considering the dynamic nonlinearity of friction coefficient and the nonlinear change of friction force distribution is established. Finally, using Matlab software, the friction distribution diagram of the contact surface of the hybrid drive three-degree-of-freedom motor under different driving and motion states is obtained. The analysis results verify the rationality of the electromagnetic piezoelectric hybrid driven three-degree-of-freedom motor. It shows that the contact state of the three sets of piezoelectric stators are determined according to the driving condition and load, the relative speed of the piezoelectric stators and the spherical rotor is proportional to the frictional force. It provides an idea for the research of contact state of hybrid drive multi-degree-of-freedom motor, and also lays a basis for further optimizing the friction interface of this kind of motors or actuators.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.