Optical differential operation based on anisotropic crystals

Many MEMS/NEMS sensors, including gyroscopes, chemical sensors, and RF filters utilize the mechanical resonance of the MEMS/NEMS structure as a highly sensitive detector. Typically, changes in the external environment lead to changes in the resonant frequency or amplitude. Due to the low-loss of micro and nano mechanical structures, large quality factors are achievable, leading to sharp resonance curves that change greatly after only small changes in the environment. This allows sensitive detectors, but also leads to poor stability and tight fabrication tolerances. This paper will discuss these issues as well as mitigation techniques including feedback control, tuning, differential operation, and sensor fusion, amongst others.

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Plate Location Based on Low Frequency Vertical Edge and Regional Searching

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.411-414.1326 ◽

2013 ◽

Vol 411-414 ◽

pp. 1326-1329

Author(s):

Yong Yang ◽

Jian Hua Wang ◽

Long Hao ◽

Na Huo

Keyword(s):

Low Frequency ◽

Operation Time ◽

Vertical Edge ◽

Location Method ◽

First Order ◽

Vertical Boundary ◽

Differential Operation ◽

Boundary Information ◽

Plate Location ◽

Region Information

The paper takes license location method based on the low-freq image vertical boundary and region searching. doing the vertical first-order differential operation on the graph, taking the vertical boundary information out, Use the line scan method into license region searching; detect region information of the suitable license texture status-hopping, the algorithm located accurately and lose less operation time than traditionally which has been achieved at the goal for license location fast and accurately.

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A New Index of Static Actuation Force Sensitivity of Mechanisms Based on Unified Forward Jacobian Matrix

Journal of Mechanisms and Robotics ◽

10.1115/1.4046976 ◽

2020 ◽

Vol 12 (6) ◽

Author(s):

Xu Wang ◽

Weizhong Guo ◽

Youcheng Han

Keyword(s):

Jacobian Matrix ◽

Screw Theory ◽

Structural Constraints ◽

Parallel Mechanisms ◽

Analysis Method ◽

Actuation Force ◽

Force Sensitivity ◽

Differential Operation ◽

Static Equation ◽

Pose Optimization

Abstract This paper proposes a novel performance index, which is called static actuation force sensitivity (SAFS), to investigate the response of the actuation forces when the amplitude of the suffered load of the end-effector has a change. Smaller SAFS can protect the actuations, and the load is mainly suffered by the structural constraints. This work starts with the construction of the unified forward Jacobian matrix of both serial and parallel mechanisms by screw theory. Then, with the forward Jacobian matrix, the inverse static equation is established. SAFS is thus introduced by the “partial differential” operation on the inverse static equation. SAFS is only related to the position of the whole mechanism and the direction of the suffered load, but not related to the detailed value of the amplitude of the load and the detailed value of the actuation forces; thus, SAFS can reveal the essence of static force capacities of the mechanisms. The example mechanism (namely, the 3revolute-prismatic-spherical (RPS) parallel mechanism) is used to illustrate the distribution of SAFS both over the workspace and at a certain pose. The analysis method of SAFS and the proposed index are expected to be applied to the pose optimization in the motion planning of the mechanisms to protect the actuations.

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