Wahyudin Syam - Wahyudin Syam (Page 2)

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.

Academic writing

Writing is about “forcing” your idea into others

Writing paper is not about marketing your idea or about conveying your idea to other people. Writing paper is more than that, it is a way to “force” your idea into people so that they use or implement your idea.

Research

Research is a broad ecosystem: All results are important!

Research is a complex ecosystem where all activities and results (in all fields) will be somehow connected, either directly or indirectly, to each other.