High Accuracy, Low-Invasive Displacement Sensor (HALIDS)

2013 ◽  
Author(s):  
Swavik Spiewak ◽  
Curtis Zaiss ◽  
Stephen J. Ludwick
Keyword(s):  
Degrees Of Freedom ◽  
Inertial Sensors ◽  
Signal Transmission ◽  
High Accuracy ◽  
Displacement Sensor ◽  
Reference Base ◽  
Root Cause ◽  
Wireless Signal ◽  
Measurement Units ◽  
6 Degrees Of Freedom

Sub-micron accuracy and precision in measuring unconstrained, spatial motion is pivotal in science and engineering. It imposes stringent requirements on the accuracy, reliability, and invasiveness of sensing devices (including lasers, lidar sensors, or optical scales). While the capabilities of these devices have seen dramatic improvements in the last decades, the needs for sub-micron accuracy, low-invasive sensors greatly outpace the available solutions. The root cause of measurement difficulties is a conflict between the very nature of motion (simultaneous translations and rotations relative to a chosen reference base) and the fundamental requirement of measurement accuracy known as the Abbe principle. Small and accurate Microsystems Technology based inertial sensors (accelerometer and gyroscopes) can alleviate, or at least significantly mitigate, many of the current difficulties. If contained in small Inertial Measurement Units (IMU) and equipped with a wireless signal transmission, they can be placed on or very close to the objects whose motion is to be measured. Furthermore, as long as the IMU, its fixture, and some region of this object around the fixture can be considered as rigid, coordinate transformation rules facilitate converting signals measured by IMU into translations and rotations of any point in this rigid region. Consequently, a virtual 6-DOF sensor can be created. Its dimensions are infinitesimally small, and it can be “placed” anywhere within the above rigid region. In particular, it can be placed such that it is collinear with the displacements of the cutting tool or robot’s end effector, and satisfies the Abbe principle. We present a High Accuracy, Low-Invasive Displacement Sensor (HALIDS) for application in manufacturing and in engineering design. The sensor is capable of measuring simultaneously 6-degrees-of-freedom displacements of objects. Its short term resolution is down to 0.1 nanometer and accuracy better than 1 micron. The sensor can be built small, light and wireless. Results from experimental evaluation of two prototype versions are presented.

Abnormalities Detection of IMU Based on PCA in Motion Monitoring

2012 ◽  
Vol 224 ◽  
pp. 533-538 ◽  
Author(s):  
Jing Zhou ◽  
Steven Su ◽  
Ai Huang Guo ◽  
Wei Dong Chen
Keyword(s):  
Measurement Method ◽  
Degrees Of Freedom ◽  
Inertial Sensors ◽  
Principal Component ◽  
Body Sensor Networks ◽  
Remote Measurement ◽  
Micro Electro Mechanical Systems ◽  
Inertial Measurement ◽  
Multiple Degrees Of Freedom ◽  
Measurement Units

Inertial measurement units (IMU) are used as an affordable and effective remote measurement method for health monitoring in body sensor networks (BSNs) based on tracking people’s daily motions and activities. These inertial sensors are mostly micro-electro-mechanical systems with a combination of multi-axis combinations of precision gyroscopes, accelerometers, and magnetometers to sense multiple degrees of freedom (DoF).Unfortunately in the process of motion monitoring actual sensor outputs may contain some abnormalities, which might result in the misinterpretations of activities. In this paper, we use Principal component analysis (PCA) combined with Hotelling’s T2 and SPE statistic to detect abnormal data in the process of motion monitoring with IMU to ensure the reliability and accuracy in application. The simulated results prove this method is effective and feasible.

Novel Device for Inputting Handwriting Trajectory

2001 ◽  
Vol 13 (2) ◽  
pp. 134-139
Author(s):  
Yasuhiro Sato ◽  
◽  
Mitsuru ShingYouuchi ◽  
Toshiyuki Furuta ◽  
Tomohiko Beppu ◽  
...  
Keyword(s):  
Data Processing ◽  
Degrees Of Freedom ◽  
Inertial Sensors ◽  
Experimental Results ◽  
Novel Device ◽  
Integration Error ◽  
Velocity Correction ◽  
6 Degrees Of Freedom ◽  
Processing Device ◽  
Additional Calculation

A pen-shaped input apparatus for inputting drawings, symbols, characters into a data processing device, such as a computer, is developed. It can trace a handwritten 2-dimensional trajectory using built-in inertial sensors. As sensors, it has 3 accelerometers and 3 gyroscopes. By detecting accelerations about 3 axes and angular rates around them as 6 degrees of freedom, it can represent the 2-dimensional trajectory of the pen tip after additional calculation. Velocity correction enables precise trajectories to be represented with a small integration error. Experimental results demonstrate the feasibility of this device as a handwritten input apparatus.

The GIOTTO Project - Building Monitoring with 6DoF Sensors

2021 ◽  
Author(s):  
Felix Bernauer ◽  
Louisa Murray-Bergquist ◽  
Felix Strobel ◽  
Joachim Wassermann ◽  
Heiner Igel ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Laboratory Experiments ◽  
Ground Motions ◽  
Strong Motion ◽  
Coda Wave ◽  
Sensor Performance ◽  
Building Monitoring ◽  
First Results ◽  
Measurement Units ◽  
6 Degrees Of Freedom

<p>Characterizing earthquake induced building damage in an efficient, automated and non-<br>invasive way is a crucial support for the decision on further usability of critical infras-<br>tructure. In the GIOTTO project (Gebäudeschwingungen: kombinierte Zustandsanalyse<br>mit innovativem Sensorkonzept) we propose to use 6 degrees of freedom sensors (6DoF)<br>to monitor the complete movement of a building structure in three rotational and three<br>translational degrees of freedom. On one side, we develop 6DoF sensor networks for<br>strong motion building monitoring on the basis of 20 inertial measurement units (IMU50<br>by iXblue, France) originally designed as north-finding gyroscopes, on the other side we<br>incorporate the new observable of rotational ground motions into the concept of coda wave<br>interferometry for continuous real-time structural health monitoring. In this contribution<br>we show first results (1) from laboratory experiments for sensor performance characteriza-<br>tion as well as (2) from a 6DoF active source experiment at a horizontal 24 m long concrete<br>beam (the BLEIB test structure hosted by the Bundesanstalt für Materialforschung und<br>-prüfung, south of Berlin, Germany).</p>

scholarly journals Prediction of dynamics and seaworthiness of amphibious hovercraft

2021 ◽  
Vol 27 (1) ◽  
pp. 22-32
Author(s):  
В.В. Зайцев ◽  
Вал.В. Зайцев ◽  
Д.В. Зайцев ◽  
В.В. Лукашова
Keyword(s):  
Mathematical Models ◽  
Degrees Of Freedom ◽  
High Accuracy ◽  
Sufficient Accuracy ◽  
Trial And Error ◽  
Slow Pace ◽  
Operational Characteristics ◽  
Depth Analysis ◽  
The Cost ◽  
6 Degrees Of Freedom

Annotation – The creation of hovercraft projects is a very expensive procedure, and the emergence of new ships of this type and their evolution is proceeding at a very slow pace. Despite the fact that hovercraft have been used for decades and there is a large amount of literature that is related to the theory of such ships and the practice of their design, there are still a number of unresolved problems associated with these ships. There are various methods, theories and publications that allow to calculate and design various complexes and systems of hovercraft, and as a result, this allows to create vessels that are successful in operation and with good seaworthiness. But at the same time, until now, the main problem remains to achieve sufficient accuracy in predicting the operational characteristics of hovercraft under various modes. Therefore, it is not uncommon for a successful hovercraft project to be born after a series of unsuccessful trial and error. The presented work describes a methodology for creating simulations of hovercraft for various modes of their operation. Various types of simulations of such ships and the ways of their implementation into functioning software are considered. The main mathematical models that are involved in the implementation of such simulations are described and their structure is shown for various hovercraft. The described complex of mathematical models, embodied in the program, allows an in-depth analysis of the dynamics and operational characteristics of hovercraft before the completion of their design and before the start of construction. It is argued that the most difficult, but suitable for real practical problems of analyzing the dynamics of hovercraft is the simulation of this ship with 6 degrees of freedom. The study allows us to conclude that the described methodology for creating a complex of mathematical models makes it possible with high accuracy to predict the dynamics of hovercraft and simulate any hovercraft with 6 degrees of freedom, which will reduce the cost of designing and building a lead hovercraft with accurately predictable seaworthiness and operational characteristics.

Systematic Calibration Method for FOG Inertial Measurement Units

2013 ◽  
Vol 662 ◽  
pp. 717-720 ◽  
Author(s):  
Zhen Yu Zheng ◽  
Yan Bin Gao ◽  
Kun Peng He
Keyword(s):  
Inertial Measurement Unit ◽  
Inertial Sensors ◽  
Calibration Method ◽  
State Equation ◽  
Measurement Unit ◽  
Observation System ◽  
Body Frame ◽  
Inertial Measurement ◽  
Measurement Units ◽  
Error Coefficients

As an inertial sensors assembly, the FOG inertial measurement unit (FIMU) must be calibrated before being used. The paper presents a one-time systematic IMU calibration method only using two-axis low precision turntable. First, the detail error model of inertial sensors using defined body frame is established. Then, only velocity taken as observation, system 33 state equation is established including the lever arm effects and nonlinear terms of scale factor error. The turntable experiments verify that the method can identify all the error coefficients of FIMU on low-precision two-axis turntable, after calibration the accuracy of navigation is improved.

4D in in vivo 2-photon laser scanning fluorescence microscopy with sample motion in 6 degrees of freedom

2011 ◽  
Vol 200 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Sabine Scheibe ◽  
Mario M. Dorostkar ◽  
Christian Seebacher ◽  
Rainer Uhl ◽  
Frank Lison ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Laser Scanning ◽  
Degrees Of Freedom ◽  
Sample Motion ◽  
6 Degrees Of Freedom

Workspace, dexterity and dimensional optimization of microhexapod

2015 ◽  
Vol 35 (4) ◽  
pp. 341-347 ◽  
Author(s):  
E. Rouhani ◽  
M. J. Nategh
Keyword(s):  
Degrees Of Freedom ◽  
Optimization Problem ◽  
Screw Theory ◽  
Design Parameters ◽  
Dimensional Synthesis ◽  
Content Type ◽  
Workspace Analysis ◽  
The Difference ◽  
Flexure Joints ◽  
6 Degrees Of Freedom

Purpose – The purpose of this paper is to study the workspace and dexterity of a microhexapod which is a 6-degrees of freedom (DOF) parallel compliant manipulator, and also to investigate its dimensional synthesis to maximize the workspace and the global dexterity index at the same time. Microassembly is so essential in the current industry for manufacturing complicated structures. Most of the micromanipulators suffer from their restricted workspace because of using flexure joints compared to the conventional ones. In addition, the controllability of micromanipulators inside the whole workspace is very vital. Thus, it is very important to select the design parameters in a way that not only maximize the workspace but also its global dexterity index. Design/methodology/approach – Microassembly is so essential in the current industry for manufacturing complicated structures. Most of the micromanipulators suffer from their restricted workspace because of using flexure joints compared to the conventional ones. In addition, the controllability of micromanipulators inside the whole workspace is very vital. Thus, it is very important to select the design parameters in a way that not only maximize the workspace but also its global dexterity index. Findings – It has been shown that the proposed procedure for the workspace calculation can considerably speed the required calculations. The optimization results show that a converged-diverged configuration of pods and an increase in the difference between the moving and the stationary platforms’ radii cause the global dexterity index to increase and the workspace to decrease. Originality/value – The proposed algorithm for the workspace analysis is very important, especially when it is an objective function of an optimization problem based on the search method. In addition, using screw theory can simply construct the homogeneous Jacobian matrix. The proposed methodology can be used for any other micromanipulator.

An improved calibration curve between soil pH measured in waterand CaCl2

Soil Research ◽  
2002 ◽  
Vol 40 (8) ◽  
pp. 1399 ◽  
Author(s):  
B. L. Henderson ◽  
E. N. Bui
Keyword(s):  
Statistical Analysis ◽  
Water Resources ◽  
Soil Ph ◽  
Calibration Curve ◽  
Smooth Function ◽  
Degrees Of Freedom ◽  
Additive Model ◽  
Smoothing Spline ◽  
Look Up Table ◽  
6 Degrees Of Freedom

A new pH water to pH CaCl2 calibration curve was derived from data pooled from 2 National Land and Water Resources Audit projects. A total of 70465 observations with both pH in water and pH in CaCl2 were available for statistical analysis. An additive model for pH in CaCl2 was fitted from a smooth function of pH in water created by a smoothing spline with 6 degrees of freedom. This model appeared stable outside the range of the data and performed well (R2 = 96.2, s = 0.24). The additive model for conversion of pHw to pHCa is sigmoidal over the range of pH 2.5 to 10.5 and is similar in shape to earlier models. Using this new model, a look-up table for converting pHw to pHCa was created.

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