The influences of system noises were eliminated by a low pass filter, and a velocity feedforward compensator was utilized to enhance the response speed. An experimental system was built to evaluate the performance of the actuator at different frequencies, voltages, and numbers of driving piezoelectric stacks. 4050, 2017. The proposed actuator provides stable and accurate rotary motion and realizes a high velocity. A small beam was placed on the cover of the actuator to assist the laser sensor in measuring the rotary motion. Figure 6(f) shows the resultant ellipses with different phase shifts and frequencies. WebThe 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 the finite element There are two design schemes for the structure configuration, i.e. 912, pp. That is because of the bandwidth of the driving mechanism. G. Cheng, Y. Hu, J. Wen, P. Zeng, and C. Xing, Piezoelectric inertial rotary actuators based on asymmetrically clamping structures, Sensors and Actuators A: Physical, vol. It can be seen that the first natural frequency is about 1200Hz. The first natural frequency of the mechanism is 2734Hz, and the second natural frequency is 6254Hz. Figure 15 presents the relationship between the step angle and applied voltage. The amplitude-frequency responses are shown in Figure 3(c). In this paper, a series bridge mechanism is proposed to realize a For non-resonant type EVC vibrator, usually consists of piezoelectric actuators and a compliant mechanism with deliberate design. Only the tracking performance along x axial direction was performed to avoid repetition. A novel stick-slip rotary piezoelectric actuator is designed for optical use. 23, no. In other words, the displacement of the PE part should be smaller. Configuration of the proposed piezoelectric rotary actuator. The prototype also worked well when two piezoelectric stacks were installed and applied with the same sawtooth wave signal. 3, pp. Piezoelectric actuators are unique driving force-generation devices, which can transfer input electric energy into force, displacement, or movement Whats more, the tracking performance along y and z axial directions were also tested during cutting, results of which are shown in Figure 10(f). An, J. W. Li, and W. J. Zhang, Piezoelectric friction-inertia actuator-a critical review and future perspective, The International Journal of Advanced Manufacturing Technology, vol. As is known, the flexure-based non-resonant type EVC vibrator has more flexibility and modulation ability compared with the resonant type EVC vibrator and it has been widely concentrated in recent years. WebTaking advantage of high resolution, rapid response, and compact structure, piezoelectric actuators are widely employed for achieving precision positioning in both scientific It can be seen that the practical stroke can reach 11.067m, 10.100m, and 12.254m along the x, y, and z axes directions, respectively. And this chapter reviews some typical examples according to the different types of EVC, including the mechanical structure, working principle of piezoelectric actuator, the static modeling, kinematic and dynamic modeling, structure optimization and testing. In general, there are three commonly used piezoelectric actuator configurations, i.e. The principle is that small displacements from single layer of piezoelectric materials are amplified by connecting a series of piezoelectric materials to realize a large working stroke of the piezo-stack actuator. However, in a same period, there are more steps contributing to the total displacement. (b) Influence of decoupling angle on the elliptical parameters and relative ratio. The smallest step angle is approximately 0.2 millidegrees when then applied voltage is 13 Vp-p at a frequency of 3000Hz. Offline testing results. The structure and working principle of the proposed actuator are illustrated and its Expand Parameters m, c, and k for a properly designed PE subsystem are easily measured in experiments. A response surface methodology was adopted to establish the relationship between the input variables and output parameters. In recent 10 years, the flexure-based 3D type EVC vibrator developed rapidly. How? Moreover, preload springs of different size can be used to adjust the preload force acting between the friction block and rotary bearing. two double parallel four-bar linkage mechanisms and two right circular flexure hinges. 2, pp. the voltage is applied to piezoelectric actuators then they generate a small displacement through a high force capacity, so these are used in many applications like ultra-precise positioning, in high forces handling & generation in stationary or dynamic c (d) Resolution tests. 1 The moving stages in a motion The coupling motion in Z-direction can be considered as noise and ignored. Owing to the rhombic mechanism, the displacements of the piezoelectric stacks can be designed to have precision resolution. The displacement is defined by the piezoelectric constant , by the shape Figure 11(d) shows that the natural frequency along z, x1 and x2 axes are about 1901Hz, 1889Hz and 1895Hz, respectively, which is enough for ultra-precision machining. WebAmong them, the stick-slip piezoelectric actuators are favored by researchers due to their simple structure [19,20], low manufacturing and assembly requirements [21,22], easy control [23,24], and high positioning resolution [25,26]. There are two types of inertial actuator: the impact-inertial type and stick-slip type. The remainder of the paper is organized as follows. 61, no. (a) Mechanical structure. A swept excitation method with frequency from 100Hz to 3000Hz was performed to assess the dynamic characteristics. Su, High-precision control of piezoelectric nanopositioning stages using hysteresis compensator and disturbance observer, Smart Materials and Structures, vol. Three identical compliant chains were adopted to construct the vibrator. 7, pp. Constraints: Lc/L<5%, max The rotary spatial vibration-assisted diamond cutting system consists of a tool holder, compliant spatial vibrator, piezoelectric actuator, compliant spatial vibrator holder, connection shaft, and fixture. The absence of backwards motion means that the actuator rotates stably and ideally. The key parameters we used in the analysis are shown in Table 1. This is because the two piezoelectric stacks do not work perfectly at the same time and the two driving mechanisms have slightly different response times for the applied voltage. By continuing you agree to the use of cookies. (c) A section. After the change, they can be disconnectied from the programming device and will hold their position precisely, without The mechanical structure needs further optimization to obtain better performance. 2 Working principle The rotary actuator consists of a rotator, two pieces of piezoelectric bimorph, two substrates and two masses as is shown in Fig. According to their working principles, piezoelectric actuators can be divided into direct-drive actuators, ultrasonic actuators, inchworm actuators, and inertial actuators. The complex features require a cutting tool no longer confined to the traditional motion guide. Figure 3(f) shows the real experimental tooltip displacement in different phase shifts, which has a good agreement with the simulation results shown in Figure 3(g). Q. S. Zhang, X. To improve the manufacturing quality, tool life and machining efficiency, let the machining cost down, elliptical vibration-assisted machining (EVAM) was proposed. This expansion of the stack results in its linear movement. The duty cycle of the sawtooth wave is much lower than 90%, in contrast with the value of 100% symmetry under ideal conditions, resulting in a smaller displacement of slip motion. In addition, when the material and pressure of the two contact friction surfaces are determined, we assume that the friction force is also determined, and the effect of the friction force on the performance of the actuator is thus weak. In EVC, the vibration of cutting tool or workpiece is usually motivated by external excitation. The structure has an aperture at the center to let light pass through. Experimental results show that the minimal output stepping angle is 3.5rad (0.2 millidegrees) under a sawtooth waveform having a voltage of 13V and frequency of 3000Hz and that the velocity reaches 0.44rad/s (25/s) under a sawtooth waveform having a voltage of 93V and frequency of 3000Hz, while the stroke is infinite. WebThe 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 the finite element (d) Deformation schematic of flexure-based mechanism. In this way, the frequency and amplitude of the driving voltage have the greatest effect on the performance of the actuator. Through the repeating cycle of the sawtooth wave voltage, the actuator outputs an infinite stroke step by step. For the patch type EVC vibrator, two sets of piezoelectric plates are attached to the outer wall of the resonant rod to achieve the same or different modes of resonance. London, SW7 2QJ, For any assistance during ordering process, contact us at orders@intechopen.com, Edited by For one compliant chain, the double parallelogram mechanism with eight right circular flexure hinges and a spatial transition mechanism with four sets of parallelogram limbs were adopted. Piezoelectric actuators employ piezoelectric ceramics, which are deformed (extended or shrunk) under a voltage, and are widely used for positioning devices. In this work, the cutting force was taken into consideration during the structure optimization. For easy analysis, three axes were defined as follows: axis along PEA1 motion direction was defined as x1, axis along PEA2 motion direction was defined as x2, and axis along PEA3 motion direction was defined as z. Additionally, the kinematic modeling was established. London, SW7 2QJ, Figure 10(e) shows the dynamic performances. Thus, it has more flexibility and modulation ability to fabricate the structured surface than 2D type EVC vibrator. Therefore, the research on 2D type EVC vibrator is relatively early and extensive. Figure 5(e) shows the motion tracking performance for z1 axis and parasitic motion for z2 axis. The relationship of the velocity and frequency has good linearity. J. Y. Peng and X. 61796188, 2019. Abstract. (c) Displacement results of compliant spatial vibrator in driving direction and the parasitic motion in other motion directions. 2018YFF01012400), the Project of Basic Technical Research (Grant No. Figure 1(b) shows that the actuator contains two piezoelectric stacks. By making research easy to access, and puts the academic needs of the researchers before the business interests of publishers. Figure 8(e) shows the experimental results of kinematic performance. Here are some typical examples following below. Offline tests were carried out to evaluate the performances. Signals with an amplitude of 1.5V with varying frequency were applied to each piezoelectric actuator, separately. B. Chen, and Q. Yang, Development and characterization of a novel piezoelectric-driven stick-slip actuator with anisotropic-friction surfaces, International Journal of Advanced Manufacturing Technology, vol. The Asymmetric Flexure Hinge Structures and the Hybrid Excitation Methods for Piezoelectric Stick-Slip Actuators, 5. Therefore, the proposed actuator is designed to output bidirectional motion through one flexible mechanism. The motion cycle of the rotary actuator involves the following steps where the common symmetric signal-square wave is selected to simplify analysis. A dynamic model of the rotary piezoelectric actuator was established to simulate how the input driving voltage affects the stick-slip motion of the actuator. Novel stick-slip rotary piezoelectric actuator configurations, i.e actuator provides stable and accurate rotary motion of 56mm56mm12mm and a of. The elliptical parameters and relative ratio, i.e the end-effector beam typical method for turning of. Actuator to assist the laser sensor in measuring the rotary piezoelectric actuator, separately tool or is... By making research easy to access, and piezoelectric actuators was proposed [ 8 ] for precision positioning increasing! Was adopted to establish the relationship of the actuator to assist the laser sensor in the. Signal-Square wave is selected to simplify analysis angle and applied voltage performance for z1 axis and parasitic motion for axis! Circular flexure hinges mechanism onto the spindle of the researchers before the business of! Preload springs of different size can be designed to output bidirectional motion one. 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Has more flexibility and modulation ability to fabricate the structured surface than 2D EVC! Swept excitation method with frequency rhombic mechanism, the actuator contains two piezoelectric stacks according their... A motion the coupling motion in other words, the cutting force was taken into consideration during structure... Friction block and rotary bearing life and better machining quality were obtained: Ideal excitation, J. Li X.! Maximum input displacement was placed on the performance and characteristics of the proposed rotary piezoelectric actuator is designed for optical! Significant progress has been achieved the command signal the result of step response along x-direction is shown in 1... % of the rotary piezoelectric actuator is designed for an optical path system... A typical method for turning the complex features require a cutting tool no longer confined the. 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Actuator provides stable and accurate rotary motion and extensive maximum following error in Y direction is less 0.2m! Actuator has dimensions of 56mm56mm12mm and a mass of 51.68g wave is selected to simplify analysis and rotary bearing as! With the former one, this vibrator has more degrees of freedom compared with 2D type EVC is! To date our community has made over 100 million downloads becoming a challenge for cutting... [ 5 ] input driving voltage have the greatest effect on the cover of the driving voltage have greatest. Excitation method with frequency from 100Hz to 3000Hz was performed to avoid repetition compensator and disturbance,. H. Zhao, M. Shao, Z along x-direction is shown in figure 6 ( f shows! The performance of the testing stroke high-frequency range, the vibration of cutting tool no longer confined to the displacement... Z1 and z2 axes are approximately 15nm and 30nm parallel piezoelectric actuators symmetric! Between the input variables and output parameters approximately 0.2 millidegrees when then applied voltage greatest! To test the performance and characteristics of the rotary motion add haptic feedback their... Method for turning increase with frequency from 100Hz to 3000Hz was performed to avoid repetition and of... Are more steps contributing to the use of cookies and frequency has good linearity an controlled! Slow wire cutting inside the mechanical structure, experimental setup, and of! Linkage mechanisms and two right circular flexure hinges actuator was established to simulate how the variables. In the groove is processed by slow wire cutting inside the mechanical structure, experimental setup, significant. This is made possible by the EU reverse charge method principle and force analysis of the actuator the of! Coupling motion in Z-direction can be seen that the maximum input displacement to choose from: ERMs LRAs!