Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
264,321
result(s) for
"PHYSICAL CONTROL"
Sort by:
Maintaining a healthy weight
Learn about healthy ways to control your diet and exercise in order to stay fit and healthy.
Book
Soil Surface-Trapping of Tomato Leaf-Miner Flies Emerging from Underground Pupae with a Simple Electrostatic Cover of Seedbeds in a Greenhouse
In the present study, an electrostatic apparatus for trapping adult tomato leaf miner flies (Liriomyza sativae) emerging from underground pupae at the surface of a seedbed in an organic greenhouse was developed. The apparatus consisted of insulated iron rods arranged in parallel at set intervals and linked to a voltage generator, which supplied a negative charge to the rods, as well as non-insulated grounded iron rods with the same configuration. The two layers of insulated and non-insulated iron rods were arrayed in parallel to form a static electric field between the layers. The electric field created a strong attractive force capable of capturing flies that entered the field. In a greenhouse assay, the apparatus was placed horizontally above a seedbed in a greenhouse and surveyed for its ability to capture adult flies emerging from pupae that were introduced onto the seedbed beneath the apparatus. The results revealed that the apparatus effectively trapped all adult flies that emerged from the pupae and that it functioned stably while continuously operated during the entire period of the experiment. Thus, our novel apparatus is a promising tool for the physical control of adult tomato leaf miners in the insecticide-independent cultivation of greenhouse tomatoes.
Journal Article
Target-Size-Dependent Application of Electrostatic Techniques for Pest Management in Greenhouses
Two new electrostatic devices were developed to manage greenhouse insect pests. One was an electrostatic insect catcher (EIC) to trap small flying pests, and the other was an arc-discharge zapper (ADZ) to kill larger insects emerging from soil beds. The EIC consisted of negatively charged insulated conductor plates (NIPs) and grounded conductor plates (GCPs), which were alternately arrayed in parallel at defined intervals. The ADZ had the same framework as the EIC, except that the NIPs were replaced with negatively charged non-insulated iron plates (NNPs). The EIC formed a non-discharging electric field between the NIP and GCP to create an attractive force to capture insects. By contrast, the ADZ formed a discharge-generating electric field between the NNP and GCP that killed insects. The EIC was effectively applied to small pests, such as whiteflies, thrips, leaf miners, winged aphids, and shore flies, that can pass through the conventional insect-proof nets installed on greenhouse windows. The ADZ was effective for adult houseflies emerging from pupae in soil beds. Our electrostatic devices are useful for controlling insect pests of different sizes.
Journal Article
An adaptive predefined time sliding mode control for uncertain nonlinear cyber-physical servo system under cyber attacks
Malicious attacks are often inevitable in cyber-physical systems (CPS). Accuracy in Cyber physical system for position tracking of servos is the major concern now a days. In high precision industrial automation, it is very hard to achieve accuracy in tracking especially under malicious cyber-attacks, control saturations, parametric perturbations and external disturbances. In this paper, we have designed a novel predefined time (PDT) convergence sliding mode adaptive controller (PTCSMAC) for such kind of cyber physical control system. Main key feature of our control is to cope these challenges that are posed by CPS systems such as parameter perturbation, control saturation, and cyber-attacks and the whole system then upgrade to a third-order system to facilitate adaptive control law. Then, we present an adaptive controller based on the novel PDT convergent sliding mode surface (SMS) combined with a modified weight updated Extreme Learning Machine (ELM) which is used to approximate the uncertain part of the system. Another significant advantage of our proposed control approach is that it does not require detailed model information, guaranteeing robust performance even when the system model is uncertain. Additionally, our proposed PTCSMAC controller is nonsingular regardless of initial conditions, and is capable of eradicating the possibility of singularity problems, which are frequently a concern in numerous CPS control systems. Finally, we have verified our designed PTCSMAC control law through rigorous simulations on CPS seeker servo positioning system and compared the robustness and performance of different existing techniques.
Journal Article
The Effects of Robots on Children with Autism Spectrum Disorder: A Meta-analysis
This study aimed to evaluate the effectiveness of robotic interventions in fostering the development of children with Autism Spectrum Disorder (ASD) and to identify key factors influencing these effects through a meta-analysis. A meta-analysis was conducted on 14 studies published between 2015 and 2024, incorporating 58 independent effect sizes and data from 408 children with ASD. A random-effects model was used to compute overall effect sizes, and moderator analyses were performed to examine factors influencing the impact of robotic interventions. The meta-analysis revealed that robotic interventions had a substantial positive impact on the development of children with ASD, with an overall effect size of d = 0.829 (95% CI = [0.657, 1.000]), indicating a large effect. Significant variability in effect sizes was observed based on the functional role of robots, specific developmental domains assessed, geographical regions, experimental design, and the inclusion of control groups. Notably, the effect size decreased as teacher involvement in interventions diminished. Additionally, meta-regression analysis showed that longer instructional session durations were positively associated with intervention effectiveness. Robotic interventions are effective in supporting the development of children with ASD, particularly when teachers are actively involved and instructional sessions are of sufficient duration. Future research should focus on optimizing intervention protocols and exploring the impact of different robot functionalities and regional contexts.
Journal Article
Collaborative optimization design framework for hierarchical filter barrier control suspension system with projection adaptive tracking hydraulic actuator
Coupling characteristics of integrated mechanical-hydraulic-control systems for active hydro-suspension with uncertain and time-varying parameters make it difficult to achieve system-level optimal performances if only through physical or control system design. A novel collaborative design framework is proposed to optimize selected variables with objectives of structural lightweight, controllable suspension performances, and energy consumption. To improve ride/handling performances of active hydro-suspension under limited chatter space and allowable tire dynamic load, nonlinear filter barrier-Lyapunov-function-based backstepping upper controller is designed to generate target force under uncertain body weight, and projection-based adaptive backstepping sliding mode bottom controller is presented for valve current adjustment to drive asymmetric actuator precisely track required target force under time-varying fluid parameters. Based on designed hierarchical controller, physical/control collaborative design problem for system-level optimization is formulated by tailored optimal objective functions/constraints, independent and coupling design variables. The solution efficiency is improved through reduced calls of physical/control systems using response extreme difference sensitivity analysis, updated initial sets, and dynamic search interval for subsequent optimization. Finally, numerical simulation is presented to verify the effectiveness and benefits of the proposed collaborative optimization hierarchical control design method with eliminated conflicts between ride comfort and suspension deformation, improved control performances, better robustness, and lighter structure.
Journal Article
Atmospheric drivers of a winter-to-spring Lagrangian sea-ice drift in the Eastern Antarctic marginal ice zone
Sea-ice drift in the Antarctic marginal ice zone (MIZ) is discussed using data from a 4-month-long drift of a buoy deployed on a pancake ice floe during the winter sea-ice expansion. We demonstrate increased meandering and drift speeds, and changes in the dynamical regimes of the absolute dispersion during cyclone activity, together with high correlations between drift velocities and wind from atmospheric reanalyses. This indicates a dominant physical control of wind forcing on ice drift and the persistence of free-drift conditions. These conditions occurred despite the buoy remaining largely in >80% ice concentrations and at distances >200 km from the estimated ice edge. The drift is additionally characterised by a strong inertial signature at 13.47 h, which appears initiated by passing cyclones. A wavelet analysis of the buoy's velocity confirms that the momentum transfer from winds at the multi-day frequencies is due to atmospheric forcing, while the initiation of inertial oscillations of sea ice has been identified as the secondary effect. Propagating storm-generated waves may initiate inertial oscillations by increasing the mobility of floes and enhance the drag of the inertial current. This analysis indicates that the Antarctic MIZ in the Indian Ocean sector remains much wider and mobile, during austral winter-to-spring, than defined by sea-ice concentration.
Journal Article
Observer aided robust control for cyber physical power grids with event triggered sliding mode controller
The growing integration of renewable energy in both islanded and interconnected microgrids has rendered Cyber-physical stability and resilience a vital area of research. Conventional controllers, including PID and linear state-feedback, are susceptible to network-induced delays, denial-of-service (DoS) attacks, and false data injection, resulting in diminished reactive power support and the risk of voltage collapse. This paper proposes an Observer-Aided Robust Control Framework that integrates an Event-Triggered Sliding Mode Controller (ET-SMC) with improved anomaly detection to address these challenges. An Extended Kalman Filter (EKF) and Sliding Mode Observer (SMO) are formulated to estimate hidden state variables and identify malicious data alterations with high sensitivity, facilitating dependable control decisions in the presence of Cyber-attacks. The performance of anti-windup PID and baseline SMC is evaluated against ET-SMC with observer augmentation, demonstrating that the proposed strategy offers enhanced robustness, quicker transient response, and diminished chattering. A stability-guaranteed Event-triggered communication protocol is developed through Lyapunov analysis to reduce bandwidth consumption while maintaining voltage and reactive power regulation. The proposed framework is validated on a real-time OPAL-RT hardware-in-the-loop (HIL) microgrid testbed, demonstrating its effectiveness in scenarios involving renewable intermittency, communication noise, and coordinated Cyber-attacks. Comparative results demonstrate that ROC-based detection performance and time-domain simulations underscore the advantages of observer-aided ET-SMC in ensuring resilient, low-bandwidth, and real-time Cyber-physical control for next-generation power grids.
Journal Article
Use of a Pair of Pulse-Charged Grounded Metal Nets as an Electrostatic Soil Cover for Eradicating Weed Seedlings
An electrostatic technique was developed to generate a simple physical method to eradicate weeds in crop fields. The proposed apparatus consisted of double-expanded metal nets connected to a pulse-charging type negative voltage generator and a grounded line. The two metal nets were arranged in parallel at an interval (6 mm) that caused no arc (spark) discharge between the negatively charged metal net (NC-MN) and the grounded metal net (G-MN). The paired nets were used as a soil cover to zap weed seedlings emerging from the ground. As plant seedlings are biological conductors, the seedling was subjected to an arc discharge from the upper metal net (NC-MN) when it emerged from the soil and passed through the lower net (G-MN). The discharge was strong enough to destroy the seedling with a single exposure. The arc treatment was highly effective for eradicating successively emerging mono- and dicotyledonous weed seedlings, regardless of the number of coexisting weeds or the area of the netted field. Thus, the present study provides a simple and reliable weed eradication method that could be integrated into a sustainable crop production system.
Journal Article