Paweł Waszczuk

Multisource system for NDT of welded elements exploited in aircraft industry

Purpose – The purpose of this paper is to describe a multisource system for nondestructive inspection of welded elements exploited in aircraft industry developed in West Pomeranian University of Technology, Szczecin in the frame of CASELOT project. The system task is to support the operator in flaws identification of welded aircraft elements using data obtained from X-ray inspection and 3D triangulation laser scanners. Design/methodology/approach – For proper defects detection a set of special processing algorithms were developed. For easier system exploitation and integration of all components a user friendly interface in LabVIEW environment was designed. Findings – It is possible to create the fully independent, intelligent system for welds’ flaws detection. This kind of technology might be crucial in further development of aircraft industry. Originality/value – In this paper a number of innovative solutions (new algorithms, algorithms’ combinations) for defects’ detection in welds are presented. All of...

Weld Joints Inspection Using Multisource Data and Image Fusion

The novel concept of comprehensive weld inspection with use of three sources of data (radiogram image, image composed of laser profilometer 3D data, CCD camera image) and weld images fusion is presented in the paper. The algorithms of data processing aimed at detection and visualization of weld flaws are roughly described. The special attention was paid at presentation and explanation of algorithm for aligning and spatial correction of images composed of data delivered by three independent sources. The results yielded by proposed algorithms for preprocessing of weld images, weld detection, feature extraction, shape extraction, shape matching, filtering, distortion correction, etc. are illustrated with several figures included in the paper. The concise description of designed and implemented laboratory stands is included in the paper too.

Object’s optical geometry measurements based on Extended Depth of Field (EDoF) approach

The authors propose a method of using EDoF in macro inspections using bi-telecentric lenses and a specially designed experimental machine setup, allowing accurate focal distance changing. Also a software method is presented allowing EDoF image reconstruction using the continuous wavelet transform (CWT). Exploited method results are additionally compared with measurements performed with Keyence’s LJ-V Series in-line Profilometer for reference matters.

Employment of the MFC/IMC structure in robust velocity controll of BLDC motor

The main purpose of this article is to present and describe the advantages of the MFC/IMC structure utilization in control of BLDC motor. The results of the analysis included in this work compare two-loop control structure containing internal model of the process with classical single-loop structure with PID controller, which is commonly used in control of industrial motors. In the framework of conducted computational and simulation tests the most important features of both structures from BLDC control point of view such as: sensitivity for load disturbance reduced to the input and output of the plant, tracking the reference value and maximum acceptable perturbations between plants and models parameters were compared.

CNC feed drive module model simplification and estimation of its parameters

Modelling of physical components such as spring-damper, mass or screw-nut mechanism gives opportunity to simulate actual behavior of a mechatronic system like a CNC feed drive module. Due to its complexity, it is crucial to conduct proper identification and then estimation process regarding only those parameters, which have the largest impact on the developed model. It is important to create functional physical model, because in practical use only those can be exploited. In this paper, a nonlinear model of a feed drive system is presented in details. Author propose a simplification method of differential equations, which were exploited to develop the model to facilitate estimation process. Results of simulations of developed model are included to confirm the correctness of made assumptions.

Sensor Fusion Based Tool-Workpiece Contact Detection in Micro-Milling

Information about distance between tool and workpiece is crucial for proper machining process. In micro-milling, due to very small tool dimensions, observation of the tool position with regard to the workpiece is possible only with a microscope. Exploiting of different signals obtained during micro-milling process in establishing the tool-workpiece contact moment is an interesting and efficient way of improving accuracy of this activity. Data from sensors contain material that could be an large source of diagnostic information, which might be helpful from different points of view. This paper presents a method for detecting a contact between a tool and a workpiece based on a fusion of the data representing the cutting forces and the accelerations. A digital signal processing algorithm introduced in this research, basing on the Fast Fourier Transform (FFT) and the Root Mean Square (RMS) calculations give positive results in field of the tool-workpiece contact detection and stands an alternative for commonly used techniques exploiting microscopes with large magnification. The method is designed to work in real-time in order to be used in practical industrial applications and satisfy demands regarding the automatic tool-workpiece contact detection.