Coupled distance sensor systems for high-accuracy topography measurement: Accounting for scanning stage and systematic sensor errors

The Sharp GP2Y0A02YK0F is categorized as a nonlinear sensor for distance measurement. This sensor is also categorized as a low-cost sensor. The higher resolution, cheap, high accuracy and easy to install are the advantages. The accuracy level of this sensor depends on the type of the measured object materials, requires an additional device unit and further processing is required since the output is non-linear. The distance determination is not easy for this type of sensor since the characteristic of this sensor fulfills non-injective function. The modelling process is one of methods to convert the output voltage of the sensor to a distance unit. The advantages of polynomial modelling are simple form model, moderate in flexibilities of shape, well known and understood properties, and easy to use for computational matters. The obstacle of polynomial-based modelling is the presence of Runge’s phenomenon. The minimization of Runge’s phenomenon can be done with decreasing the model order. The piecewise Newton polynomials with vertex determination method have been succeeded to generate a nonlinear model and minimize the occurrence of Runge’s phenomenon. The low level of MSE by 0.001 and error percentage of 2.38% has been obtained for the generated model. The low MSE level leads to the high accuracy level of the generated model.

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A Fast and High-Accuracy Compass Alignment Method to SINS with Azimuth Axis Rotation

Mathematical Problems in Engineering ◽

10.1155/2013/524284 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12 ◽

Cited By ~ 4

Author(s):

Xixiang Liu ◽

Xiaosu Xu ◽

Yiting Liu ◽

Lihui Wang

Keyword(s):

Navigation System ◽

Calculation Method ◽

Inertial Navigation System ◽

Inertial Navigation ◽

Low Frequency ◽

High Accuracy ◽

Alignment Accuracy ◽

Alignment Method ◽

Axis Rotation ◽

Sensor Errors

Azimuth axis rotating modulation was introduced to improve the alignment accuracy of strapdown inertial navigation system (SINS) through compass algorithm, in which the limit accuracy was determined by equivalent sensor errors in the eastern and northern direction. In this modulation, horizontal sensor errors were modulated into zero mean periodic variables. Furthermore, two methods were introduced to ensure alignment accuracy and speed: (1) shortened rotating cycle and redesigned compass parameters were selected to eliminate or ease the amplification to low-frequency senor error inputs in compass loop caused by rotation and (2) a data repeated calculation method was designed to shorten prolonged alignment time caused by the above redesigned parameters. Based on a certain SINS, turntable test proves that alignment accuracy and time were significantly improved and slightly shortened in comparison with the classical compass alignment.

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High-Accuracy Form Measurement with Multiple Sensor Systems

Frontiers in Optics ◽

10.1364/fio.2005.ftue1 ◽

2005 ◽

Author(s):

Michael Schulz

Keyword(s):

High Accuracy ◽

Sensor Systems ◽

Multiple Sensor

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A New 1,000 kV Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100061318 ◽

1967 ◽

Vol 25 ◽

pp. 260-261

Author(s):

M. Nishigaki ◽

S. Katagiri ◽

H. Kimura ◽

B. Tadano

Keyword(s):

Electron Microscope ◽

High Voltage ◽

Basic Research ◽

Chromatic Aberration ◽

High Accuracy ◽

Biological Specimen ◽

Voltage Electron ◽

High Voltage Electron Microscope ◽

High Voltage Electron

The high voltage electron microscope has many advantageous features in comparison with the ordinary electron microscope. They are a higher penetrating efficiency of the electron, low chromatic aberration, high accuracy of the selected area diffraction and so on. Thus, the high voltage electron microscope becomes an indispensable instrument for the metallurgical, polymer and biological specimen studies. The application of the instrument involves today not only basic research but routine survey in the various fields. Particularly for the latter purpose, the performance, maintenance and reliability of the microscope should be same as those of commercial ones. The authors completed a 500 kV electron microscope in 1964 and a 1,000 kV one in 1966 taking these points into consideration. The construction of our 1,000 kV electron microscope is described below.

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