Preliminary Computational Analysis of Three Configurations for an Innovative Ventricular Chamber

(1) Background: shape, dimension, hemodynamics, and hemocompatibility are just a few of the several challenging key points that must be addressed in designing any suitable solution for the ventricular chamber of mechanical circulatory support devices. A preliminary evaluation of different geometries of bellow-like ventricular chambers is herein proposed. The chambers were made with a polycarbonate urethane that is acknowledged to be a hemocompatible polymer. (2) Methods: an explicit dynamic computational analysis was performed. The actuation of the three chambers was simulated without the presence of an internal fluid. Maximum stress and strain values were identified, as well as the most critical regions. Geometric changes were checked during simulated motion to verify that the dimensional constraints were satisfied. (3) Results: one chamber appeared to be the best solution compared to the others, since its dimensional variations were negligible, and effective stresses and strains did not reach critical values. (4) Conclusions: the identification of the best geometric solution will allow proceeding with further experimental studies. Fluid–structure interactions and fatigue analyses were investigated.

A Deep-Learning Method for Radar Micro-Doppler Spectrogram Restoration

Radio frequency interference, which makes it difficult to produce high-quality radar spectrograms, is a major issue for micro-Doppler-based human activity recognition (HAR). In this paper, we propose a deep-learning-based method to detect and cut out the interference in spectrograms. Then, we restore the spectrograms in the cut-out region. First, a fully convolutional neural network (FCN) is employed to detect and remove the interference. Then, a coarse-to-fine generative adversarial network (GAN) is proposed to restore the part of the spectrogram that is affected by the interferences. The simulated motion capture (MOCAP) spectrograms and the measured radar spectrograms with interference are used to verify the proposed method. Experimental results from both qualitative and quantitative perspectives show that the proposed method can mitigate the interference and restore high-quality radar spectrograms. Furthermore, the comparison experiments also demonstrate the efficiency of the proposed approach.

Virtual Simulation and Experimental Verification for 3D-printed Robot Manipulators

SUMMARY The objective of this work is to construct a robot that is based on 3D printing to meet the low-cost and light structures. The Computer-aided-design model is used with LabVIEW to simulate the given trajectory. Users of the simulation of such methodology can preview the simulated motion and perceive and resolve discrepancies between the planned and simulated paths prior to execution of a task. The advantages of this study are the lack of need to mount extra sensors on realistic robot to measure joint space coordinates, simplifying the hardware. These outcomes can also be used in an undergraduate robotics course.

Modeling the motion processes of a multifunctional robot for animal units

The goal of the research is a mathematical modeling of the motion process of a wheeled robot along a given trajectory with the turn drill. Matlab software with the Simulink option package was used as the environment for artificial modeling of the motion process. In order to control the movement of a wheeled robot using the computational and graphic methods, a kinematic and dynamic model of a wheeled robot was determined. The robot has two independent drive wheels located on the same axis and operating on electric traction. Based on the obtained mathematical correlations, a nomenclature of artificial components was formed in the Matlab (Simulink) environment, which made possible to simulate the process of controlling the robot’s electric drive. A voltage that was twice as different was applied to the electric drive of independent wheels located on the same axis as a reliability check of the mathematical model in the Matlab (Simulink) artificial medium. The artificially simulated motion process of a wheeled robot involved studying the motion process using the “PLOT (X; Y)” function. At the moment of the robot’s movement, the trajectory of the 00 point, which is the center of robot’s mass, for a set unit of time, was obtained. This allowed confirming the reliability of the developed mathematical model for the control system of a multifunctional robot for animal units.

Kinematic Modeling of a Combined System of Multiple Mecanum-Wheeled Robots with Velocity Compensation

In industry, combination configurations composed of multiple Mecanum-wheeled mobile robots are adopted to transport large-scale objects. In this paper, a kinematic model with velocity compensation of the combined mobile system is created, aimed to provide a theoretical kinematic basis for accurate motion control. Motion simulations of a single four-Mecanum-wheeled virtual robot prototype on RecurDyn and motion tests of a robot physical prototype are carried out, and the motions of a variety of combined mobile configurations are also simulated. Motion simulation and test results prove that the kinematic models of single- and multiple-robot combination systems are correct, and the inverse kinematic correction model with velocity compensation matrix is feasible. Through simulations or experiments, the velocity compensation coefficients of the robots can be measured and the velocity compensation matrix can be created. This modified inverse kinematic model can effectively reduce the errors of robot motion caused by wheel slippage and improve the motion accuracy of the mobile robot system.

A novel motion cueing algorithm integrated multi-sensory system–Vestibular and proprioceptive system

Motion cueing algorithms are used to produce a motion which feels as realistic as possible while remaining in the limited workspace of driving simulators. Several optimal motion cueing algorithms were developed to improve both the exploitation of the workspace of a driving simulator and the realistic of the simulated motion. In the dynamics model of the optimal motion cueing algorithms, several kinds of motion-sensory systems are integrated to optimize the simulated motion sensation. However, most previous works have just focused on the visual and vestibular system. The mathematical model of the proprioceptive system, that also senses the non-visual motion, has rarely been concerned. In this paper, a novel optimal motion cueing algorithm, which integrates model of the proprioceptive system, is developed to reduce the false cues from muscle spindle of head/neck system sensing lateral tilted angle. The optimal motion cueing algorithm has a significant effect on the pilot's perception when the tilted angle is rather large. An example of the simulation of a roller coaster running along a planar S-curve trajectory with only lateral acceleration is investigated with current motion cueing algorithms and optimal motion cueing algorithm. Several objective criteria were introduced to evaluate the simulated perception of all investigated motion cueing algorithms. The results demonstrate that optimal motion cueing algorithm is better than current motion cueing algorithms in most criteria and also sub-criteria.