Metrology Error compensation for coordinate measuring instrument: Error separation and self-calibration Rehearsal method is a method to separate combined or coupled errors into separated individual error elements. By separating the combined errors into individual errors, the error quantification of an instrument can be performed without a calibrated artefact and/or calibration instrument.
Metrology Error compensation for coordinate measuring instrument: The mathematical model of 3-axis coordinate measuring machine (CMM) The mathematical model of a measuring instrument is important for building the error compensation system for the instrument.
Metrology Error compensation for coordinate measuring instrument: Steps and calibration instruments For the implementation of error compensation on measuring instruments or machine tools, there are steps to follow, that are the reconstruction of an error map (via mathematical modelling via analytical or empirical methods) and the calibration process to quantify and characterise the error map.
Metrology Error compensation for coordinate measuring instrument: introduction and types Error compensation is an important process to produce an accurate measuring instrument. Any measuring instruments, although inherently constituted by accurate and precise components, always have some degree of error.
Research Disruptive innovation to create growth: A research perspective Economic growth is one of the main targets of a nation to reach prosperity. It is well known that developed nations leverage knowledge-based economic created from advanced research and high-value products or services.
Metrology X-Ray computerised tomography (X-ray CT) for industrial part measurement: History, working principle, measurement procedure, applications and characteristics X-Ray computerised tomography (X-ray CT) has the ability to non-destructively measure internal features of a part that is made of different materials including metals and non-metals.
GNSS Correlator outputs for clean and spoofed GPS L1 C/A signals The pseudorange and navigation data determination from global navigation satellite system (GNSS) signals are calculated from the correlator outputs at the tracking stage of the GNSS signal processing.
GNSS Public datasets for spoofing and evil waveform (EWF) signals Spoofing attacks on GNSS signals become more serious than ever due to the advancement of spoofing algorithms and computational capabilities and processing. These spoofing attacks transmit a counterfeit signal that leads to a wrong positioning, timing and navigation (PNT) solutions.
Research Reverse step: building research and knowledge from data or observation study Research is an iterative process and can be performed in either forward or reverse steps. Different fields of research require different research steps that best suit the specific situation of each field.
Metrology Mathematical geometrical fitting: Direct least-square fitting of circle geometry (with tutorial and code) Circle is a non-linear geometry that has a non-linear mathematical model. In this post, a closed-form and deterministic method to fit a circle from points (e.g., obtained from a measurement) by using direct least-square (DLS) estimation method is presented.
Metrology Mathematical geometrical fitting: Automatic measurement algorithm case studies In this post, practical case studies of algorithm implementations for automatic geometrical perpendicularity and cutting tool measurements are presented.
Metrology Mathematical geometrical fitting: Data filtering of measurement points Data filtering is a process to reduce noises or supress certain components or information contained in measurement data by using a specific kernel (filter).
Metrology Mathematical geometrical fitting: Initial solution problems Any iterative optimisation algorithms, used to optimise non-linear and multi-modal objective functions, always require an initial solution estimation.
Metrology Mathematical geometrical fitting: Non-linear geometry least-squared fitting (with tutorial) The fitting process for non-linear geometry is more complex than that for the linear geometry fitting. Non-linear geometry includes circle (2D and 3D), sphere, cylinder, cone and torus as well as more complex geometries such as free-form surfaces.
Metrology Mathematical geometrical fitting: Linear geometry least-squared fitting (with tutorial) The least-squared fitting of linear geometry is solved by transforming a non-linear objective function of residuals into a linear objective function of the residuals.
Metrology Mathematical geometrical fitting: Concept and fitting methods One of instrumental aspects in dimensional, geometrical and surface texture measurements is an algorithm to mathematically fit a geometry to spatial points. These spatial points are captured and digitised by a measuring instrument.
Metrology Optical measuring instrument: Focus variation microscopy (FVM) for coordinate and surface texture measurements Focus variation microscopy (FVM) is an optical coordinate measuring machine (CMM) that is able to measure both micro-scale part geometry and areal surface texture. An FVM machine can have an up to 5-axis motion system.
Research Research: Lessons learnt from “Hands of Time: A Watchmaker's History of Time” Time is the only thing that all humans have equally. Whether they come from a royal family or from an ordinary family, they all have the same 24 hours per day!
GNSS Post-correlation Carrier to Noise Density (C/N0) calculation in GNSS signal processing Carrier to Noise Density (C/N0) is one of instrumental metrics for GNSS receiver and signal processing. In this post, C/N0 is calculated at the post-correlation stage (signal tracking) in the GNSS signal processing stage [1].
Research Research as value and economy creation activities In this post, we will discuss how to estimate the value (in cash) that can be generated from a research activity. In finance, cash is king!
Applied programming The problem of writing high-digit numbers into a file and its solution In this post, the problem of writing a real number with high digit to a file in scientific and numerical computing is presented and discussed.
Tolerancing Geometric dimensioning and tolerancing (GD&T) and assembly of additive manufacturing parts In this post, the challenge of applying geometrical dimensioning and tolerancing (GD&T) on additive manufactured (AM) or 3D printed parts will be discussed.
Tolerancing Geometric dimensioning and tolerancing (GD&T) and assembly of aerospace parts The assembly feature design and tolerance stack-up analysis of aerospace parts are very important for the analysis of assembly variations or deviations.
Metrology Uncertainty estimation of laser interferometry measurements Length or distance measurement with a laser interferometer has an important application in various engineering and scientific fields.
Metrology Optical measuring instrument: Point auto-focus (PAI) for coordinate and surface texture measurements Point auto-focus (PAI) optical measuring instrument works based on the principle of following the focus position of a microscope objective lens. This auto-focus mechanism follows the height of the surface of a measured object.
