precision motion
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2022 ◽  
pp. 1-48
Author(s):  
Yijie Liu ◽  
Zhen Zhang

Abstract Electron beam lithography (EBL) is an important lithographic process of scanning a focused electron beam (e-beam) to direct write a custom pattern with nanometric accuracy. Due to the very limited field of the focused election beam, a motion stage is needed to move the sample to the e-beam field for processing large patterns. In order to eliminate the stitching error induced by the existing “step and scan” process, we in this paper propose a large range compliant nano-manipulator so that the manipulator and the election beam can be moved in a simultaneous manner. We also present an optimization design for the geometric parameters of the compliant manipulator under the vacuum environment. Experimental results demonstrate 1 mm × 1 mm travel range with high linearity, ~ 0.5% cross-axis error and 5 nm resolution. Moreover, the high natural frequency (~ 56 Hz) of the manipulator facilitates it to achieve high-precision motion of EBL.


Actuators ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 331
Author(s):  
Zhenle Dong ◽  
Yinghao Yang ◽  
Geqiang Li ◽  
Zheng Zhang

For the demands of a high precision motion control of an uncertain electro-mechanical launching platform, a novel integrated error constraint asymptotic control in the presence of parametric uncertainties and uncertain disturbance is proposed, of which the barrier function method and a continuous asymptotic control design are integrated for the first time. The former technique can effectively avoid excessive tracking errors at the transient phase, which is caused by the disturbance and the large uncertain system parameters’ deviation between the initial estimated value and the actual value, by selecting a proper barrier threshold, while the latter technique can handle the uncertain disturbance to achieve asymptotic tracking. A rigorous stability analysis is given to illustrate the theoretical performance. In addition, as a supplementary measure, repetitive control is employed to estimate and compensate the possible periodic-like disturbance under certain conditions. Two experimental cases on a prototype of a launching platform demonstrate the effectiveness of the proposed controller.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Jinghai Han

With the continuous development of social economy, robots gradually replace human beings in many aspects of auxiliary work, but it is worth noting that orderly, accurate, and safe operation is the reasonable form of robot movement. In view of the existing limitations, this study combines the gradient matching algorithm, by using a high-precision motion matching for the visual system, improves the automation precision, and, at the same time, picking fruit image smoothing and enhancement, achieves fruit edge feature extraction; the simulation experiments proved that matching the gradient algorithm is effective and can realize the visual and actions match together and support picking robot movement.


2021 ◽  
Author(s):  
Mohammad Al Saaideh ◽  
Natheer Alatawneh ◽  
Mohammad Al Janaideh
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