共查询到20条相似文献,搜索用时 31 毫秒
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A. Ferreira C. Cassier S. Hirai 《Mechatronics, IEEE/ASME Transactions on》2004,9(2):321-333
We proposed an automated micromanipulation workcell for visually servoed teleoperated microassembly assisted by virtual reality techniques. It is composed of two micromanipulators equipped with microtools operating under a light microscope. Visual servoing techniques are applied for efficient and reliable position/force feedback during microassembly tasks. First, a pushing-based micromanipulation strategy for the microobject to follow a planned trajectory is proposed under vision based-position control. Then, we present the cooperation control strategy of the microhandling operation under vision-based force control integrating a sensor fusion framework approach. A guiding-system based on virtual microworld exactly reconstructed from the CAD-CAM databases of the real environment being considered is presented for the imprecisely calibrated microworld. Finally, a planned scenario is executed and experimental results of microassembly tasks performed on millimeter-sized components are provided. 相似文献
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Design and Fabrication of a Four-Arm-Structure MEMS Gripper 总被引:1,自引:0,他引:1
Tao Chen Liguo Chen Lining Sun Xinxin Li 《Industrial Electronics, IEEE Transactions on》2009,56(4):996-1004
This paper is focused on the design and fabrication of a four-arm-structure microelectromechanical systems gripper integrated with sidewall piezoresistive force sensors. Surface and bulk micromachining technologies are employed to fabricate the microgripper from a single-crystal silicon wafer (i.e., no silicon-on-insulator wafer is used). A vertical sidewall surface piezoresistor etching technique is used to form the side direction force sensors. The end effector of this gripper is a four-arm structure: two fixed cantilever arms integrated with piezoresistive sensors are designed to sense the gripping force. The resolution of the force sensor is in the micronewton range and, therefore, provides feedback of the forces that dominate the micromanipulation processes. An electrostatically driven microactuator is designed to provide the force to operate the other two movable arms. In this way, it creates a deflection of 25 mum at the arm tip, and the range of the operation is 30-130 mum. Experimental results show that it can successfully provide force sensing and play a main role in preventing the damage of microparts in micromanipulation and microassembly tasks. 相似文献
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《Mechatronics, IEEE/ASME Transactions on》2009,14(4):504-514
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微装配技术的研究进展及其展望 总被引:3,自引:0,他引:3
微装配是电子制造、微制造、机器人操作等制造领域的共性前沿技术之一,近年来得到了广泛的研究与应用.首先,指出了微装配技术与纳米装配技术的本质区别,阐明了尺度效应和粘附效应给微装配技术带来的问题与挑战;分别介绍了传统微装配技术和新兴自装配技术的最新研究进展,讨论了一些急待解决的关键技术问题;最后对微装配技术的研究趋势进行了展望. 相似文献
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《Mechatronics》2014,24(6):590-604
In this paper, modeling and control strategies for a new observability-optimized piezoelectric microactuator are presented. The targeted applications mainly concern the design of microgripper for micromanipulation tasks. The device has been designed using a topological optimization method, which takes into account the optimal full integration of piezoelectric actuating and sensing elements within the device. It is achieved in link with modal controllability and observability considerations. The vibrational modes that govern the tip deflection of the monolithic compliant structure are proved to be fully observable by the integrated sensing area of the device. The proposed control strategy permits to simply reconstruct the deflection using electric charges measurement and modal state observer. Finally, the vibrations that are naturally induced by the flexible structure are successfully damped using robust and low order controller. 相似文献
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《Mechatronics》2007,17(8):462-467
This paper reports on the design and modeling of an endoscopic tooth-like tactile sensor which is capable of measuring compliance of a contact tissue/sensed object. Present day endoscopic graspers are designed to be tooth-like in order to grasp slippery tissues. They are not, however, able to measure tissue tactile properties such as force and softness. In this work, proof of a conceptual and innovative design of an endoscopic piezoelectric tactile sensor is presented. The main objective of this study is to design and model a piezoelectric sensor capable of measuring the total applied force on the sensed object, as well as the compliance of the tissue/sensed object. Detecting the sensed objects compliance is based on the relative deformation of contact object/tissue on the rigid and compliant elements. One polyvinylidene fluoride (PVDF) film is placed between the rigid cylinder and the plate and is responsible for the measurement of the force applied on the rigid element. Another PVDF film is sandwiched between the two base plates to measure the total force applied on the sensor. The compliance of the sensed object is measured by recording the PVDF films response under different load sets. The data obtained for the force variation are plotted against the modulus of elasticity of the sensed object. We used finite element modeling results as a basis of comparison for the experimental data. The agreement between the theoretical predictions and the experimental data is reasonable and within the acceptable range. 相似文献
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In order to improve the precision of static load pressure recognition and identify the position of the applied force accurately, a fiber Bragg grating (FBG) flexible sensor array is proposed in this work. Numerical analysis for the package thickness (4 mm) and package position (2 mm from the bottom) of the FBG flexible sensor is performed using COMSOL, and optimal package thickness (4 mm) and package position (2 mm from the bottom) are selected in the analysis. By using 12-FBGs layout method and random forest algorithm, the position and load prediction model is established. The results show that the average error of the distance between the prediction points of coordinates X-Y and static load F and the real sample points is 0.092. Finally, to verify the proposed models, the pressure sensing experiments of the flexible FBG array are carried out on this basis. The weights of 100 g to 1 000 g are applied to different regions of the flexible sensor array one by one in accordance with a certain trajectory. The variation of each FBG wavelength was taken as the input of the stochastic forest prediction model, and the coordinate position and the static load size F were taken as the output to establish the prediction model. The minimum distance error between the actual point and the predicted point was calculated by experiment as 0.03491. The maximum is 0.2481, and the mean error is 0.1515. It is concluded that the random forest prediction model has a good prediction effect on the pressure sensing of the flexible FBG sensing array. 相似文献
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In this paper we present development of a sensing and actuation mechanism along with its controller for an Interfacial Force Microscope. The device can be used as a micro-scale force sensor or actuator using a feedback control scheme that regulates the interaction force between the probe tip and the sample. The mechanism is essentially a force balancing system consisting of a torsion bar and two variable gap parallel plate capacitors with a sharp probe attached to the moving plate of one of the capacitors. The capacitors are utilized to measure the air gap distance and act as electrostatic actuators to compensate the force applied to the sensor tip. Given that the system is nonlinear with respect to the control input, a nonlinear feedback linearization scheme coupled with a dynamic output feedback controller is developed and integrated with available measurement and computing hardware. The dynamic controller requires measurement of position information only and provides improved performance when compared to conventional controllers. Experimental studies are conducted for nanoindentation and imaging applications and performance of the controller is evaluated. 相似文献
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《Electron Devices, IEEE Transactions on》1979,26(5):815-817
A novel "soft-touch" contact sensor and analog position-indicating device is described. It uses a double-layer PVF2 piezoelectric bimorph-type cantilever structure. An ac voltage applied across one layer causes mechanical vibration. The piezoelectric output signal from the other layer provides information on the presence and position of an external object. 相似文献
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Lamb波损伤监测技术是近年来结构健康监测研究的热点之一。由于Lamb波传播过程中存在频散及多模效应,监测过程中结构响应信号十分复杂,给信号处理和分析带来困难。根据压电元件激励与传感模型,对Lamb波模式调制及选择方法进行了分析研究,给出了基于压电元件的选择性模式激励与接收原理,实现对期望模式的激发和采集,简化响应信号及后续处理。在铝板结构上的实验研究验证了方法的有效性。 相似文献
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Cheng Hou Kaiyao Wang Fengxia Wang Hanyang Li Liang Lou Songsong Zhang Yuandong Gu Huicong Liu Tao Chen Lining Sun 《Advanced functional materials》2023,33(43):2302812
In robotic-assisted minimally invasive surgery (RMIS), non-sentient surgical instruments make it impossible for surgeons to perceive operational force during the procedure. To facilitate surgeons with force telepresence during surgery, a highly integrated MEMS-based piezoresistive 3D force sensing module, which is composed of a MEMS-based piezoresistive sensor chip, an encapsulation cap with miniature pyramids, and a top elastic layer, is demonstrated. This innovative combined construction allows for rapid replacement of elastic layers with different thicknesses and different Young's modulus, so as to realize an adjustable sensitivity and measurement range for different surgeries. By replacing the elastic layer, the same amount of change in resistance can be achieved for external force of 3 and 10 N in the Z-axis; the sensitivity in X- and Y-axes can be increased by a maximum of eight and seven times, respectively. Meanwhile, miniature size enables it to be integrated into various surgical instruments’ tip. Experimental demonstrations involving palpation simulated nodule detection of kidney, ex vivo puncture, and threading forces estimation of tissue-mimicking are conducted to validate the effectiveness of adjusting sensitivity and range. This sensing module is potentially a promising solution for low-cost and versatility to surgical instruments, which can facilitate unification of force-sensing/intelligent surgical instruments. 相似文献
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In this paper, a new desktop NC machine tool with the ability of compliance control is presented for finishing of metallic molds with small curved surface. The NC machine tool consists of a three-axis robot whose single one has a high position accuracy of 1 μm, which means that it can perform higher resolutions of position and force, compared to general industrial robots. A ball-end abrasive tool is attached to the tip of z-axis through a force sensor. In order to first confirm the application limit of an industrial robot to a finishing task, we evaluate the backlash that causes inaccuracy in position at the tip of the abrasive tool, by simply measuring the position and force. The basic resolution of the proposed NC machine tool is shown through the similar position and force measurement to one used in the conventional robot. Next, a CAD/CAM-based position/force control method with a fine-velocity pulse converter is proposed for a pulse-based servo controller that actuates the single-axis of the robot. We further introduce a systematic method for tuning a desired damping, which is coming from the critically damped condition used in a static force control system. The desired damping is the most important factor when an impedance model following force control is applied. Finally, to evaluate the characteristics of the NC machine tool, a profiling control experiment is conducted along a spiral path for a plastic lens mold with axis-symmetric concave areas. Consequently, it is confirmed that the proposed NC machine tool has a good performance, which can be applied to the finishing process of plastic lens molds. 相似文献
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钢丝绳传动在航空光学遥感器上的应用 总被引:1,自引:0,他引:1
针对某航空光学遥感器扫描组件和消旋组件需以高精度同步旋转的要求,提出一种通过双电机驱动,采用独立的位置环和速度环控制的钢丝绳精密传动方法。首先,详细介绍了钢丝绳精密传动的结构形式和控制方法,并简要分析了钢丝绳的传动刚度,最后,通过实验对钢丝绳精密传动的精度进行测试,同时分析了预紧力和负载力对精度的影响。实验结果表明:本钢丝绳精密传动系统实现了扫描组件和消旋组件旋转同步精度0.03°,旋转速度为5°/s时稳速精度达1.5%,满足设计要求。实验结果验证了本钢丝绳精密传动应用方法的可行性,为钢丝绳精密传动在航空光学遥感器上的应用提供了一种新的方法。 相似文献
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A discrete-time control law which gives the optimal applied force for a given position trajectory of a linear second-order external load is computed using linear quadratic regulator (LQR) theory. This control law is used with an existing first-order fixed interpulse interval (IPI) muscle force controller to regulate position in a simulated electrically stimulated loaded agonist-antagonist muscle system. Both force and position feedback are required to implement the control strategy. A nonlinear second-order model of a predominantly slow twitch muscle is used in the simulation. The results suggest that good position control of a loaded antagonist-agonist muscle system is possible if a linear model of the external load is appropriate. 相似文献
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Originated from aerospace area, smart material structures have been a research hotspot in the application of engineering. For structural health monitoring within the context of civil engineering, the research about high-performance sensing units are very important. As one of the piezoelectric materials belonging to smart ones, Polyvinylidene Fluoride (PVDF) is widely regarded for its property advantages of low cost, good mechanical abilities, high sensibility, and corrosion resistance. In this paper, for the validation of PVDF sensors as sensing units for bridge structural local monitoring, wireless experimental systems of PVDF sensor for structural local monitoring on a bridge model and beam were built. Firstly, based on the operating mechanism, the measurement circuit and the characteristics of PVDF are introduced. Secondly, system framework of PVDF sensor for local monitoring is proposed, a bridge model is built, wireless sensor kits are then developed. Finally, Bridge damage monitoring experiments have been done for structural local health monitoring using PVDF sensors. The experimental results show that PVDF sensor can handle structural impact response monitoring and damage detection of civil engineering, and the developed wireless sensor experimental system can be easily implemented for use in practical monitoring engineering. 相似文献