Continuous passive motion (CPM) machines are used in the rehabilitation of members that have been injured to recover their range of motion and prevent stiffness. Nowadays, some CPM machines for the knee, ankle, arm, and elbow are available commercially. In this paper, ankle and shoulder rehabilitation robots, based on an X-Y table, are presented. The novelty of these rehabilitation robots is that they have a computerized numerical control system, resulting in low-cost machines. Some G-codes for basic and combined movement routines for ankle and shoulder rehabilitation are presented. In addition, the use of a robust generalized PI controller is also proposed to guarantee safe rehabilitation movements and compensate for passive stiffness in the ankle joint of stroke survivors. Some numerical simulations are included to illustrate the dynamic performance of the robust Generalized Proportional Integral (GPI) controller using the virtual prototype.

The current paper addresses the lack of explicit analytical solutions for stress evaluations in variable-thickness flywheels by proposing an approximate formulation for conical profiles, where thickness varies linearly along the radius. The main objective was to develop a compact and practical expression to estimate radial and tangential stresses without relying on finite element analysis. Starting from a stress function, the model was simplified under the assumption of a small-thickness gradient, allowing the derivation of a closed-form solution. The resulting expression explicitly relates stresses to geometric and material parameters. To validate the approximation, stress distributions were computed for various outer-to-inner thickness ratios and compared with results obtained through FEA. The comparison, evaluated using the coefficient of determination, mean absolute percentage error, root mean squared error, normalized root mean squared error, and stress ratios, demonstrated strong agreement, especially for moderate-thickness ratios ($1\leqq t_o/t_i\leqq 4.5$). The method was more accurate for radial stress than tangential stress, particularly at higher gradients. The results confirmed that the proposed analytical approach provides a reliable and efficient alternative to numerical methods in the design and optimization of conical flywheels, offering practical value for early-stage engineering analysis and reducing reliance on time-intensive simulations.

Powering lower limb assistance/augmentation systems throughout long time periods is one of the major challenges in such an area. Researchers have proposed many solutions to diminishing energy consumption in such systems, many of which rely on the user’s biomechanics, that is, the design is intended to take advantage of the user’s inertia to spare/store energy in some subphases of the walking cycle and use or release it in the subphases with the greatest energy requirement. We have approached this issue and developed a lower limb exoskeleton that would spare up to 47% of the energy required throughout the walking cycle. We have achieved this by adding a clutch at the hip to set it passive during the stance phase. Such a mechanism could be implemented in a wide range of lower limb exoskeletons with successful results.

The equilibrium equation for a variable thickness flywheel is approximated analytically, assuming that the flywheel’s thickness varies linearly and as smoothly as to neglect it. The solution shows an accurate approximation of maximum radial and tangential stresses, with respect to finite element method, for a wide range of outer/inner thickness relation. The performance of the results was quantified with the Pearson correlation factor, the mean absolute percentage error, and the relation between the maximum stresses calculated with FEA and the results obtained with the obtained solution.

This study explores the structural and microstructural effects of Dy doping on the magneto‐crystalline properties of (Fe ₈₁ Al ₁₉ ) _{100‐ x} Dy _x ( x = 0, 0.05, 0.10, and 0.15) alloys prepared by the arc melting technique. All compositions exhibited a single‐phase body‐centered cubic (BCC) A2 structure, corresponding to the Im m space group (No. 229). Progressive Dy incorporation led to an increase in lattice parameters and promoted the development of preferential orientation, particularly along the (200) and (310) crystallographic planes, as confirmed by inverse pole figure analysis. A total magnetostriction (λ _∥ ‐λ _⊥ ) enhancement is found in all doped samples, increasing from 28 ppm for the undoped alloy to a maximum of 92 ppm in the x = 0.10 composition. Further Dy additions did not yield additional improvements, suggesting a change in the grains of the microstructure accompanied by defect generation. Additionally, significant variations in average crystallite shape were found, mainly due to growth in the (200) plane, indicating stress accumulation. The magnetostriction enhancement is primarily attributed to a reduction in average maximum strain and, secondary, to the preferential orientation development. The x = 0.10 alloy exhibited a favorable (200) preferential orientation fraction of 57.3% and the lowest average maximum strain value of 55.3×10 ⁻⁴ .