We present transport measurements of a tunable silicon metal-oxide semiconductor double quantum dot device with lateral geometry. The experimentally extracted gate-to-dot capacitances show that the device is largely symmetric under the gate voltages applied. Intriguingly, these gate voltages themselves are not symmetric. A comparison with numerical simulations indicates that the applied gate voltages serve to offset an intrinsic asymmetry in the physical device. We also show a transition from a large single dot to two well isolated coupled dots, where the central gate of the device is used to controllably tune the interdot coupling.

This paper explores the design, control, construction, and leading manufacturers of upper limb rehabilitation robots through a thorough literature review. Utilizing databases such as Scopus, IEEE Xplore, Science Direct, Springer Link, and the Clinical Trials database, the research adhered to a rigorous screening process in accordance with PRISMA guidelines. This included analyzing abstracts and conducting comprehensive reviews of full articles when necessary. A total of fourteen relevant papers were systematically selected for in-depth analysis. The study offers a detailed classification of robotic technologies along with their Technology Readiness Levels (TRLs), discusses the primary challenges hindering their adoption, and proposes strategic research directions to address these issues. In conclusion, while upper limb robotic devices exhibit significant potential, persistent technological and design challenges must be addressed, underscoring the need for ongoing research and multidisciplinary collaboration to facilitate broader and more effective adoption.

In this paper a comparison between two popular fault detection methodologies is performed for detecting rotor broken bars in an induction motor: Motor Current Signature Analysis (MCSA) and Vibration Analysis. Tests are performed in a 3-phase, 2 hp induction motor dedicated for this type of study. Experiments are performed under different levels of fault severity and load conditions. Analysis of each signal is carried out in Matlab ^® environment. Experimental results show different performance in fault detection and evaluating the fault severity of each technique under different load scenarios. As a result, MCSA is recommended when the motor is running under a significant load condition. Meanwhile, vibration analysis is suggested under low load regimes.

This study presents the mathematical modelling, system identification using grey-box model estimation and position-tracking control for an electro-hydraulic servo system (EHSS) using four control strategies based on LQR formulation: Linear quadratic regulator (LQR) approach for servo systems, linear quadratic integral (LQI), linear quadratic tracking (LQT) and a variation of LQT named here LQTβ. First, the nonlinear model of the electro-hydraulic servo system was obtained using differential equations based on hydraulic theory and physical laws. The model was then linearized and its parameters were estimated using grey-box method when the open-loop system was excited with a chirp signal from 0 to 30 [Hz]. The estimated model was verified with experimental data of the open-loop system response for square wave and continuous step inputs of different amplitudes and frequencies. For the position-tracking four control strategies based on LQR formulation were proposed. The main difference among them is the conception of the cost function that is minimized: the LQR includes all the system’s states and the control signal, the LQI includes all system’s states, the tracking error and the control signal, the LQT includes only the tracking error and the LQTβ the tracking error and its derivative. The four control strategies were simulated in MATLAB Simulink and initially tuned using Bryson’s rule, then were implemented in the real system and finely tuned by trial and error until the best performance is achieved. They all were tested using step, square wave and sine wave inputs, and were analyzed in terms of settling time, rising time, peak time, overshoot margin, steady-state error, energy consumption and repeatability against a conventional PID controller. The experimental results showed better tracking, better repeatability and less energy consumption using the LQR based techniques than using the PID control, specifically the LQR and the LQTβ showed the fastest response and smallest steady-state error among the LQR based strategies. This study was carried out with the electro-hydraulic servo system (EHSS) of the seismic shaker table of the Dynamics and Structural Control Lab at Universidad Industrial de Santander. The seismic shaker table is composed of a Parker double rod dynamic hydraulic cylinder commanded by an MTS 252.24G-04 servo valve and powered by an MTS 505.11 hydraulic power unit. Cylinder’s position was measured using an integrated Trans-Teck LVDT. The control system was build and implemented in MATLAB Simulink using Quanser Q8-USB card.

Quantum dot (QD) layouts are becoming more complex as the technology is being applied to more sophisticated multi-QD structures. This increase in complexity requires improved capacitance modeling both for the design and accurate interpretation of QD properties from measurement. A combination of process simulation, electrostatic simulation, and computer-assisted design (CAD) layout packages are used to develop a 3-D classical capacitance model. The agreement of the classical model's capacitances is tested against two different, experimentally measured, topographically complex silicon QD geometries. Agreement with experiment, within 10%-20%, is demonstrated for the two structures when the details of the structure are transferred from the CAD to the model capturing the full 3-D topography. Small uncertainties in device dimensions due to uncontrolled variation in processing, like layer thickness and gate size, are calculated to be sufficient to explain the disagreement. The sensitivity of the capacitances to small variations in the structure also highlights the limits of accuracy of capacitance models for QD analysis. We furthermore observe that a critical density, the metal-insulator transition, can be used as a good approximation of the metallic edge of the QD when electron density in the dot is calculated directly with a semiclassical simulation.