Application of Computer Vision and Python Scripts as Educational Mechatronic Platforms for Engineering Development in STEM Technologies

This paper presents the process of designing, fabrication, assembling, programming and optimizing a prototype of a nonlinear mechatronic Ball-Plate System (BPS) as a laboratory platform for STEM engineer education. Due to the nonlinearity and complexity of BPS, task presents challenging issues, such as: 1) difficulties in controlling the stabilization of a given position point known as steady state error, 2) position resolution known as specific distance error and 3) adverse environmental effects - light shadow error, also discussed in this paper. The laboratory BPS prototype for education was designed, manufactured and installed at the Karlovac University of Applied Sciences at the Department of Mechanical Engineering, Study of mechatronics. The low-cost two degrees BPS system uses a USB HD camera for computer vision as feedback and two DC servomotors as actuators. Due to controlling problems, an advanced block diagram of control system is proposed and discussed. An open-source control system based on Python scripts that allows the use of ready-made functions from the library allows changing the color of the ball and the parameters of the PID controller, thus indirectly simplifying control system and directly the mathematical calculation. The authors will continue their research on this BPS mechatronic platform and control algorithms.

Two-wave laser displacement meter

A two-wave laser displacement meter based on Michelson interferometer has been developed for measurements at an unknown temperature profile at the measurement trace. The requirements for meteorological parameters support during displacement measurements using the offered laser interferometer are less strict compared to using an one-wave interferometer. The article describes the optical schematic of the device. The results for the measurements of the developed laser interferometer for realization of the displacement unit within the limits of 60 m are presented. The weather condition influence on measurements was estimated. The application of pseudorandom displacement of the interferometer’s reference arm with accumulation made possible the reflector position resolution down to 0.01 μm the stoped-displacement mode, and down to 0.05 μm at the displacement mode. It was shown that such resolution allows to measure displacements at trace up to 60 m with inaccuracies less than 10 μm at the temperature profile amplitude up to 1 °C.

Determination of Position Resolution for LYSO Scintillation Crystals Using Geant4 Monte Carlo Code

LYSO scintillation crystals, due to their significant characteristics such as high light yield, fast decay time, small Moliére radius, and good radiation hardness, are proposed to be used for the electromagnetic calorimeter section of the Turkish Accelerator Center Particle Factory (TAC-PF) detector. In this work, the center of gravity technique was used to determine the impact coordinates of an electron initiating an electromagnetic shower in a LYSO array, in a calorimeter module containing nine crystals, each 25 mm × 25 mm in cross-section and 200 mm in length. The response of the calorimeter module has been studied with electrons having energies in the range 0.1 GeV-2 GeV. By using the Monte Carlo simulation based on Geant4, the two-dimensional position resolution of the module is obtained as σ R mm = 3.95 ± 0.08 / E ⊕ 1.91 ± 0.11 at the center of the crystal.

Pulse-shape calculations and applications using the AGATAGeFEM software package

A software package for modeling segmented High-Purity Segmented Germanium detectors, AGATAGeFEM, is presented. The choices made for geometry implementation and the calculations of the electric and weighting fields are discussed and models used for charge-carrier velocities are described. Numerical integration of the charge-carrier transport equation is explained. The impact of noise and crosstalk on the achieved position resolution in AGATA detectors is investigated. The results suggest that crosstalk, as seen in the AGATA detectors, is of minor importance for the position resolution. The sensitivity of the pulse shapes to the parameters in the pulse-shape calculations is determined as a function of position in the detectors. Finally, AGATAGeFEM has been used to produce pulse-shape data bases for pulse-shape analyses of experimental data. The results with the new data base indicate improvement with respect to those with the standard AGATA data base. The AGATAGeFEM package sets itself apart with its high precision of the detector geometry description. This lends itself to numerical studies of the impact of segmentation lines and charge diffusion in the next step of code development.

Enhanced Monitoring of Sleep Position in Sleep Apnea Patients: Smartphone Triaxial Accelerometry Compared with Video-Validated Position from Polysomnography

Poor sleep quality is a risk factor for multiple mental, cardiovascular, and cerebrovascular diseases. Certain sleep positions or excessive position changes can be related to some diseases and poor sleep quality. Nevertheless, sleep position is usually classified into four discrete values: supine, prone, left and right. An increase in sleep position resolution is necessary to better assess sleep position dynamics and to interpret more accurately intermediate sleep positions. This research aims to study the feasibility of smartphones as sleep position monitors by (1) developing algorithms to retrieve the sleep position angle from smartphone accelerometry; (2) monitoring the sleep position angle in patients with obstructive sleep apnea (OSA); (3) comparing the discretized sleep angle versus the four classic sleep positions obtained by the video-validated polysomnography (PSG); and (4) analyzing the presence of positional OSA (pOSA) related to its sleep angle of occurrence. Results from 19 OSA patients reveal that a higher resolution sleep position would help to better diagnose and treat patients with position-dependent diseases such as pOSA. They also show that smartphones are promising mHealth tools for enhanced position monitoring at hospitals and home, as they can provide sleep position with higher resolution than the gold-standard video-validated PSG.

Accessing tens-to-hundreds femtoseconds nuclear state lifetimes with low-energy binary heavy-ion reactions

A novel Monte Carlo technique has been developed to determine lifetimes of excited states in the tens-to-hundreds femtoseconds range in products of low-energy heavy-ion binary reactions, with complex velocity distributions. The method is based on a detailed study of Doppler-broadened $$\gamma $$ γ -ray lineshapes. Its relevance is demonstrated in connection with the $$^{18}\text {O}(7.0\, \text {MeV/u})+\,^{181}\text {Ta}$$ 18 O ( 7.0 MeV/u ) + 181 Ta experiment, performed at GANIL with the AGATA+VAMOS+PARIS setup, to study neutron-rich O, C, N, ... nuclei. Excited states in $$^{17}\text {O}$$ 17 O and $$^{19}\text {O}$$ 19 O , with known lifetimes, are used to validate the method over the $$\sim 20{-}400\,\text {fs}$$ ∼ 20 - 400 fs lifetime-sensitivity range. Emphasis is given to the unprecedented position resolution provided by $$\gamma $$ γ -tracking arrays, which turns out to be essential for reaching the required accuracy in Doppler-shift correction. The technique is anticipated to be an important tool for lifetime investigations in exotic neutron-rich nuclei, produced with intense ISOL-type beams.

Enhanced position resolution for ZnS:Ag/$$^6$$LiF wavelength shifting fibre thermal neutron detectors

The high neutron intensity, improvements in neutron delivery and increasingly more complex experiments at neutron scattering facilities, i.e. J-PARC, SNS, ISIS, CSNS and ESS, which is presently under construction, drive the development of neutron scattering instruments and their associated detectors. High position resolution is one of the most demanding detector requirements and is particularly relevant of neutron reflectometry applications. Scintillator detectors using ZnS:Ag/$$^6$$ 6 LiF coupled to wavelength shifting fibre (WLSF) are currently employed in several neutron scattering facilities, including J-PARC, SNS, ISIS and CSNS. For WLSF-based scintillation detectors, the position reconstruction is routinely achieved by determining the combination of fibres that absorb scintillation light. The use of position reconstruction algorithms, analysing light spread in the system, leads to an increase in the position resolution. The optimisation of a centre of gravity interpolation method for linear position-sensitive detectors has been developed, and a factor 2 improvement in position sensitivity has been achieved. The investigation of the light spread over the fibres and the detector performance in correlation with the reconstructed position resolution are discussed.