Direct Control Research Articles

From Science Fiction to Reality: Exploring Brain-Computer Interfaces and their Human Applications

Direct control of mechanical or electrical equipment through mental activity is made possible by brain-computer interfaces (BCIs), often referred to as brain-machine interfaces (BMIs). Using only brain signals, users of BCIs can operate external systems without using neurostimulators, which trigger neural tissues. This allows users to avoid using peripheral neurological and muscle systems. The brain's ability to incorporate and regulate mechanical devices as extensions of its own physiological processes is demonstrated by this capability.When it comes to helping those with severe impairments, BCI systems have a lot of potential uses. For people who suffer from neurological conditions like amyotrophic lateral sclerosis, brainstem stroke, or spinal cord injury who are completely paralyzed or "locked in," they provide a substantial benefit in terms of communication. By directly converting brain intent into executable commands, BCI technology aims to enable communication. This is especially helpful for those who are unable to speak.Neuroprosthetics, which attempt to restore lost motor and sensory functions, have been the main focus of BCI research and development. These systems make use of artificial devices to treat brain-related illnesses, take over for faulty nervous system functions, and compensate for compromised sensory organs. As this science develops, brain-computer interfaces (BCIs) have the potential to improve cognitive capacities and the quality of life for people with severe disabilities.

When in Debt, Appoint Women? A Re-Examination of Aid, Debt, and the Inclusion of Women in African Cabinets

Abstract Are more aid-dependent and indebted countries more likely to include women in their cabinets? Several studies have suggested that such countries seek to please donors and lenders. Focusing on Africa, we test whether leaders respond to international incentives and, specifically, signal donors and lenders that they value gender equality in political decision-making. Although leaders have more direct control over the gender composition of the cabinet than the legislature, our analyses do not show that aid dependence and indebtedness result in more women in either the cabinet or the legislature. We operationalize aid dependence and indebtedness as a proportion of recipient gross national income, which we argue better reflects the aid and loan recipients’ vulnerability to external pressure. Using regression analysis techniques and multiple robustness checks to evaluate our panel data, our findings remain consistent with arguments that African states have stronger bargaining positions than the foreign aid literature has acknowledged.

Essential Features and Torque Minimization Techniques for Brushless Direct Current Motor Controllers in Electric Vehicles

Essential Features and Torque Minimization Techniques for Brushless Direct Current Motor Controllers in Electric Vehicles

Sb2S3/AlGaAs-based reconfigurable metasurface for dynamic polarization and directionality control of quantum emitter emission.

In this article, we report, to the best of our knowledge, for the first time, phase change material (PCM)-based reconfigurable metasurfaces for tailoring different degrees of freedom (DoF) of the quantum emitter (QE) emission, namely polarization and directionality, two key controlling factors in applications such as quantum computing, communication, and chiral optics. We have used a hybrid plasmon-QE coupled bullseye grating system utilizing the unexplored concept of composite nano-antennas in quantum photonics as the basic building block of the structures. Carefully engineered azimuthal width profile of the Sb2S3/AlGaAs composite ridge and selectively controlled transition of PCM (Sb2S3) states provide dynamic control over the amplitude and phase of the scattered radiation. Based on this methodology, we have designed five different metasurfaces for on-demand switching of target DoFs of QE emission, ensuring high collection efficiency due to the near-field coupling scheme. The first two metasurfaces switch the majority of the outgoing radiation from radially polarized to circularly polarized, whereas the next two switch the direction of circularly polarized outgoing radiation by a maximum of 9.23° while maintaining the spin state (or polarization chirality) in the simulation environment. The third metasurface category is capable of on-demand generation and separation of opposite spin states of outgoing radiation by 11.48° utilizing the selectively controlled phase transition of Sb2S3. Such reconfigurable multi-dimensional manipulation of QE radiation has not been investigated previously. This work proves the vast potential of active metasurfaces to modify the DoFs of QE emission, paving the way for high-dimensional quantum sources for high-speed quantum communication, higher dimensional quantum processing, and switchable chiral optics.

Kinematic and neuromuscular characterization of cognitive involvement in gait control in healthy young adults.

The signature of cognitive involvement in gait control has rarely been studied using both kinematic and neuromuscular features. The present study aimed to address this gap. Twenty-four healthy young adults walked on an instrumented treadmill in a virtual environment under two optic flow conditions: normal (NOF) and perturbed (POF, continuous mediolateral pseudorandom oscillations). Each condition was performed under single-task and dual-task conditions of increasing difficulty (1-, 2-, 3-back). Subjective mental workload (raw NASA-TLX), cognitive performance (mean reaction time and d-prime), kinematic (steadiness, variability and complexity in the mediolateral and anteroposterior directions) and neuromuscular (duration and variability of motor primitives) control of gait were assessed. The cognitive performance and the number and composition of motor modules were unaffected by simultaneous walking, regardless of the optic flow condition. Kinematic and neuromuscular variability was greater under POF compared to NOF conditions. Young adults sought to counteract POF by rapidly correcting task-relevant gait fluctuations. The depletion of cognitive resources through dual-tasking led to reduced kinematic and neuromuscular variability and this occurred to the same extent regardless of simultaneous working memory (WM) load. Increasing WM load led to a prioritization of gait control in the mediolateral direction over the anteroposterior direction. The impact of POF on kinematic variability (step velocity) was reduced when a cognitive task was performed simultaneously, but this phenomenon was no modulated by WM load. Collectively, these results shed important light on how young adults adjust the processes involved in goal-directed locomotion when exposed to varying levels of task and environmental constraints.

Automatic Power Direction Control of Dual Active Bridge/Triple Active Bridge Converter in Emergency Energy Supply for Sustainability

Automatic Power Direction Control of Dual Active Bridge/Triple Active Bridge Converter in Emergency Energy Supply for Sustainability

Restoration of grasping in an upper limb amputee using the myokinetic prosthesis with implanted magnets.

The loss of a hand disrupts the sophisticated neural pathways between the brain and the hand, severely affecting the level of independence of the patient and the ability to carry out daily work and social activities. Recent years have witnessed a rapid evolution of surgical techniques and technologies aimed at restoring dexterous motor functions akin to those of the human hand through bionic solutions, mainly relying on probing of electrical signals from the residual nerves and muscles. Here, we report the clinical implementation of an interface aimed at achieving this goal by exploiting muscle deformation, sensed through passive magnetic implants: the myokinetic interface. One participant with a transradial amputation received an implantation of six permanent magnets in three muscles of the residual limb. A truly self-contained myokinetic prosthetic arm embedding all hardware components and the battery within the prosthetic socket was developed. By retrieving muscle deformation caused by voluntary contraction through magnet localization, we were able to control in real time a dexterous robotic hand following both a direct control strategy and a pattern recognition approach. In just 6 weeks, the participant successfully completed a series of functional tests, achieving scores similar to those achieved when using myoelectric controllers, a standard-of-care solution, with comparable physical and mental workloads. This experience raised conceptual and technical limits of the interface, which nevertheless pave the way for further investigations in a partially unexplored field. This study also demonstrates a viable possibility for intuitively interfacing humans with robotic technologies.

Preparation and Preclinical Characterization of a Simple Ester for Dual Exogenous Supply of Lactate and Beta-hydroxybutyrate.

Elevation of the plasma levels of (S)-lactate (Lac) and/or (R)-beta-hydroxybutyrate (BHB) occurs naturally in response to strenuous exercise and prolonged fasting, respectively, resulting in millimolar concentrations of these two metabolites. It is increasingly appreciated that Lac and BHB have wide-ranging beneficial physiological effects, suggesting that novel nutritional solutions, compatible with high-level and/or sustained consumption, which allow direct control of plasma levels of Lac and BHB, are of strong interest. In this study, we present a molecular hybrid between (S)-lactate and the BHB-precursor (R)-1,3-butanediol in the form of a simple ester referred to as LaKe. We show that LaKe can be readily prepared on the kilogram scale and undergoes rapid hydrolytic conversion under a variety of physiological conditions to release its two constituents. Oral ingestion of LaKe, in rats, resulted in dose-dependent elevation of plasma levels of Lac and BHB triggering expected physiological responses such as reduced lipolysis and elevation of the appetite-suppressing compound N-L-lactoyl-phenylalanine (Lac-Phe).

Controlling lamination and directional growth of β-sheets via hydrophobic interactions: The strategies and insights

The self-assembling morphologies of proteins, nucleic acids, and peptides are well correlated with their functioning in biological systems. In spite of extensive studies for the morphologies regulating, the directional control of the assembly morphology structure for the peptides still remains challenging. Here, the directional structure control of a bola-like peptide Ac-KIIF-CONH2 (KIIF) was realized by introducing different amount of acetonitrile to the system. The morphologies were characterized by transmission electron microscopy (TEM) and atomic force microscopy (AFM), and the secondary structure was evaluated by circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR). The results demonstrated that the introducing of different amount of acetonitrile has significantly tuned the hydrophobic interactions amongst the side chains, thus affecting the self-assembling morphologies. As acetonitrile content increased, the assemblies changed from nanotubes to helical/twisted ribbons and then to thin fibrils, with a steady decrease in the width. In contrast, the assemblies changed from thin fibrils to helical/twisted ribbons, and then to matured nanotubes, exhibiting a steady increase in the width with peptide concentration increasing. Complementary molecular dynamics (MD) simulations demonstrated the important role of acetonitrile in controlling the hydrophobic interactions, providing microscopic evidence for the structure transition process. We believe such observations provide important insights into the design and fabrication of functional materials with controlled shape and size.

Enhancing HVAC multivariable system performance through hybrid modeling and direct Nyquist Array control

This study explores a closed-loop multivariable control system for HVAC systems. A hybrid distributed parameter-lumped model was developed using MATLAB’s System Identification Application, resulting in a transfer function matrix. The Direct Nyquist Array (DNA) control strategy was applied, dividing the HVAC system into two SISO loops, each equipped with PID controllers. Stability analysis confirmed system stability according to the Nyquist criterion. Simulation of the system under DNA control showed improved performance over the open-loop setup, with faster response times of nearly 1 s and overshoots between 7% and 15%, maintaining thermal comfort and occupant satisfaction. The system effectively managed ambient heat transfer variations, maintaining desired airflow rate and air temperature. The closed-loop setup exhibited robustness against disturbances, quickly returning to steady-state values. Settling times ranged from 1 to 2 s with minimal impact on HVAC performance. Overall, the closed-loop multivariable DNA control with SISO PID controllers proved reliable for enhancing energy efficiency and thermal comfort in HVAC systems. Practical application This study provides a comprehensive framework for multivariable control in HVAC systems, significantly benefiting built environment professionals by enhancing energy efficiency and occupant comfort. By applying advanced control strategies, the research offers practical solutions for optimizing HVAC performance, reducing operational costs, and ensuring sustainability in building management. The detailed analysis and methodologies presented can be directly implemented to improve system reliability and responsiveness, thereby supporting professionals in creating smarter, more resilient, and environmentally friendly built environments.

Direct torque control of switched reluctance motor driven by full bridge power converter

Direct torque control of switched reluctance motor driven by full bridge power converter

Intelligent Control System for Brain-Controlled Mobile Robot Using Self-Learning Neuro-Fuzzy Approach.

Brain-computer interface (BCI) provides direct communication and control between the human brain and physical devices. It is achieved by converting EEG signals into control commands. Such interfaces have significantly improved the lives of disabled individuals suffering from neurological disorders-such as stroke, amyotrophic lateral sclerosis (ALS), and spinal cord injury-by extending their movement range and thereby promoting self-independence. Brain-controlled mobile robots, however, often face challenges in safety and control performance due to the inherent limitations of BCIs. This paper proposes a shared control scheme for brain-controlled mobile robots by utilizing fuzzy logic to enhance safety, control performance, and robustness. The proposed scheme is developed by combining a self-learning neuro-fuzzy (SLNF) controller with an obstacle avoidance controller (OAC). The SLNF controller robustly tracks the user's intentions, and the OAC ensures the safety of the mobile robot following the BCI commands. Furthermore, SLNF is a model-free controller that can learn as well as update its parameters online, diminishing the effect of disturbances. The experimental results prove the efficacy and robustness of the proposed SLNF controller including a higher task completion rate of 94.29% (compared to 79.29%, and 92.86% for Direct BCI and Fuzzy-PID, respectively), a shorter average task completion time of 85.31 s (compared to 92.01 s and 86.16 s for Direct BCI and Fuzzy-PID, respectively), and reduced settling time and overshoot.

Vehicle Stability Control Based on Vehicle Motion State and Tire Force Estimation

The direct yaw moment control system is able to greatly enhance the vehicle stability when driving on challenging road surfaces. This paper introduces a direct control approach for managing the vehicle yaw moment, utilizing terminal sliding mode control and a Square Root Cubature Kalman Filter (SRCKF). Initially, the longitudinal and lateral forces acting on the vehicle's tires are estimated through a sliding mode observer. Subsequently, the SRCKF algorithm and the four-wheel tire force are employed to accurately estimate the yaw rate and sideslip angle. Based on these estimations, additional yaw moments are determined using the terminal sliding mode control algorithm, and a combined control of yaw rate and sideslip angle is achieved through a threshold method. A rule-based braking force distribution strategy is then implemented to ensure vehicle stability control. Simulation results demonstrate that the tire force estimations from the sliding mode observer and the vehicle yaw rate and sideslip angle estimations from the SRCKF algorithm closely align with the output results from Carsim, with an error margin of less than 15%. The braking force distribution strategy, based on the direct yaw moment control using the terminal sliding mode algorithm, effectively tracks the desired yaw rate and sideslip angle.

Robust fuzzy controller design with FPGA implementation for matrix converter based induction motor drive

This paper aims to design a controller for a matrix converter fed induction motor drive providing less torque ripples and eliminating peak overshoots with good transient and steady state responses utilizing fuzzy and direct torque control. The proposed controller utilizes Direct Torque Control (DTC) strategy with space vector modulation for regulating stator flux and electromagnetic torque. Due to the superior control capabilities of the matrix converter such as bidirectional power flow, sinusoidal input/output waveforms, high power density and lesser volume, it has attracted significant research interest in the field of adjustable speed drive. Hence the proposed matrix converter based controller is developed in MATLAB/Simulink and tested in different input/output conditions. To validate simulation results, a laboratory prototype is built around the Altium Nano Board 3000 equipped with a Xilinx Spartan using Field Programmable Gate Array (FPGA) is employed. The proposed control scheme, validated through simulation and hardware testing, ensures stable, robust drive system with significant reductions in input side harmonics and enhances induction motor drive's performance.

Surface Passivation of Norland Optical Adhesive Improves the Guiding Efficiency of Gliding Microtubules in Microfluidic Devices.

The microtubule-kinesin biomolecular motor system, which is vital for cellular function, holds significant promise for nanotechnological applications. In vitro gliding assays have demonstrated the ability to transport microcargo by propelling microtubules across kinesin-coated surfaces. However, the uncontrolled directional motion of microtubules has posed significant challenges, limiting the system's application for precise cargo delivery. Microfluidic devices provide a means to direct microtubule movement through their geometric features. Norland Optical Adhesive (NOA) is valued for its mold-free application in microfluidic device fabrication; however, microtubules often climb up channel walls, limiting controlled movement. In this study, a surface passivation method for NOA is introduced, using polyethylene glycol via a thiol-ene click reaction. This technique significantly improved the directional control and concentration of microtubules within NOA microchannels. This approach presents new possibilities for the precise application of biomolecular motors in nanotechnology, enabling advancements in the design of microfluidic systems for complex biomolecular manipulations.

A Direct Contour Control Method for Free-Form Surface Machining Trajectories Based on Coordinate Transformation

The requirement for high-speed and high-precision contouring with free-form surfaces in the CNC machining process is increasing. The contour error is an essential criterion for the quality of CNC machining. For the problem of contour error control, the present research is mainly based on position tracking, and the control method directly aiming at contour control has not been well studied. This paper proposed a new type of coordinate transformation-based direct contour control method (CT-DCC) for free-form surface machining trajectories. By real-time monitoring of the contour error and the foot point of the free-form parametric trajectory, the contouring task is decomposed into the contour error control task in the normal direction and the velocity control problem in the feed direction. Using coordinate transformation, the output commands of the two tasks are converted to the axial motion command. CT-DCC completely eliminates position tracking in the traditional control to achieve direct control of the contour error, which provides a new solution for the contour control problem of free-form surface machining. Both the axial velocity control and the axial torque control-based CT-DCC scheme were studied, and the two-axis and three-axis direct contour controllers were tested. The simulation and experiment results show the feasibility of the proposed method.

Experimental Implementation of a TD3 Agent Based Speed Controller for Direct Torque Control of PMSM Drives

This manuscript presents a novel control approach for Permanent Magnet Synchronous Motors (PMSMs) by integrating the widely used Direct Torque Control (DTC) method with Deep Reinforcement Learning (DRL), specifically the Twin Delayed Deep Deterministic Policy Gradient (TD3) algorithm. The TD3 algorithm is well-suited to address the challenges posed by high-dimensional state and action spaces in PMSM drives. The conventional Proportional–Integral (PI) controller in the outer loop of DTC is replaced with the DRL based TD3 agent to overcome the limitations of traditional PI controllers, such as model dependency and complex parameter tuning. The DRL technique allows the agent to learn optimal control policies from experience, making it suitable for complex and nonlinear control problems. Extensive simulation studies demonstrate the effectiveness of the TD3-based control in achieving accurate speed tracking under varying operating conditions. Real-time experimental validation using a TMS320F28379D digital signal processor confirms the feasibility of the proposed DRL based approach. The research offers new insights into improving the performance of PMSM drives and paves the way for future advancements in electric drive control.

Boosting hydrogenation properties of supported Cu-based catalysts by replacing Cu0 active sites

Balancing the Cu+/Cu0 ratio is a common strategy to improve catalytic activity of Cu-based catalysts but is still constrained by low atomic utilization and the inherent nature of charge distribution. Herein, we reported a strategy of replacing the Cu0 active sites in Cu-based catalysts by constructing bimetallic sites on ceria, which consist of spatially separated trace amounts of palladium metal and plate-shaped Cu+ clusters with one-atom layers. The catalytic activity of the prepared Cu100Pd1/CeO2-FA catalyst (using formic acid) was 4 times that of conventional Cu100Pd1/CeO2-H catalyst in selective hydrogenation of 5-hydroxymethylfurfural to 2,5-bis(hydroxymethyl)furan, even outperforming some existing noble metal catalysts. Multiple characterizations and theoretical calculations demonstrated that the Pd atom is the heterolytic activation site for H2 molecules while plate-shaped Cu+ metal clusters act as effective hydrogenation places. This directional control involving both spatial relationship and electronic structure of the active site provides a new strategy for designing hydrogenated catalysts.

Strategy of Out-Fold Double Eyelid Corrected Into In-Fold: Low Position Design, Direction Control Suture, and Fat Transfer.

Double eyelid surgery is a common but delicate cosmetic procedure in Asia. Because of the precise requirements and technical reasons, patients who received blepharoplasty may not satisfied with their out-fold crease. Some patients are born with unsatisfied out-fold double eyelids. The medial creases of double eyelid were higher than should be. In this study, the authors developed a strategy to correct out-fold crease of double eyelid to in-fold to satisfy patients' requirements. From January 2022 to May 2024, 102 patients (96 females and 6 males) were included in this retrospective analysis. Patients with out-fold double-eyelid inborn or obtained. The patients were divided into 3 groups: inborn out-fold double-eyelid, obtained double-eyelid with epicanthus, and obtained double-eyelid without epicanthus. The surgical strategy contained low position design, direction control suture, and fat transfer. Preoperative and postoperative images were collected, and patients' satisfaction and complications were evaluated. In total, 102 consecutive patients were included in this study, with an average follow-up of 11.9 months. Eleven patients had inborn out-fold creases, and 83 patients had out-fold creases with epicanthus after primitive blepharoplasty, and 8 patients had out-fold creases without epicanthus after primitive blepharoplasty. Ninety-six (94.12%) patients were satisfied with their results. Complications included narrow double eyelid width (n =1, 0.98%), asymmetric creases (n=2, 1.96%), incompletely in-fold creases (n=3, 2.94%), and subtle fork in medial creases (n=4, 3.92%). The surgical strategy, which contained low-position design, direction control suture, and fat transfer, could correct out-fold creases of double-eyelid into in-fold effectively.

Campaign Prop Handling by Bandung City Bawaslu in Realizing Environmental Cleanliness

The policies passed and stipulated by the government in the election to pay attention to the optimization of Bawaslu's policies in Law No.7 of 2017 concerning general elections as election organizers and the optimization of Bawaslu's policies regarding the control of campaign props in General Election Commission Regulation No. 20 of 2023 on the amendment of General Election Commission Regulation No. 15 of 2023 this regulation shows the government's attention so that the elections are held properly, in accordance with applicable regulations. The conceptual control model will make it easier for policy implementers to be on target, by realizing the control of campaign props in accordance with the targets, as well as zoning areas that have been set in Bandung City. The research used is based on the skinative method and descriptive analysis, through the Hasibuan theory including direct control, indirect control, and exception control related to the handling of campaign props by the Bandung City Bawaslu