Control Design Research Articles

Stability analysis of random fractional-order nonlinear systems and its application

The research on stability analysis and control design for random nonlinear systems have been greatly popularized in recent ten years, but almost no literature focuses on the fractional-order case. This paper explores the stability problem for a class of random Caputo fractional-order nonlinear systems. As a prerequisite, under the globally and the locally Lipschitz conditions, it is shown that such systems have a global unique solution with the aid of the generalized Gronwall inequality and a Picard iterative technique. By resorting to Laplace transformation and Lyapunov stability theory, some feasible conditions are established such that the considered fractional-order nonlinear systems are respectively Mittag-Leffler noise-to-state stable, Mittag-Leffler globally asymptotically stable. Then, a tracking control strategy is established for a class of random Caputo fractional-order strict-feedback systems. The feasibility analysis is addressed according to the established stability criteria. Finally, a power system and a mass–spring-damper system modeled by the random fractional-order method are employed to demonstrate the efficiency of the established analysis approach. More critically, the deficiency in the existing literatures is covered up by the current work and a set of new theories and methods in studying random Caputo fractional-order nonlinear systems is built up.

Optimization of Power Control for Autonomous Hybrid Electric Vehicles with Flexible Power Demand

Abstract Technology advancement for on-road vehicles has gained significant momentum in the past decades, particularly in the field of vehicle automation and powertrain electrification. The optimization of powertrain controls for autonomous vehicles typically involves a separated consideration of the vehicle's external dynamics and powertrain dynamics, with one key aspect often overlooked. This aspect, known as flexible power demand, recognizes that the powertrain control system does not necessarily have to precisely match the power requested by the vehicle motion controller at all times. Leveraging this feature can lead to control designs achieving improved fuel economy by adding an extra degree of freedom to the powertrain control while maintaining safety and drive comfort. The present research investigates the use of an Approximate Dynamic Programming (ADP) approach to develop a powertrain controller, which takes into account the flexibility in power demand within the ADP framework. The concept of reachable sets is incorporated into the ADP framework to ensure safety, improve ride comfort, and enhance the accuracy of the optimization solution. The formulation is based on an autonomous hybrid electric vehicle (HEV), while the methodology can also be applied to other types of vehicles. It is also found that necessary customization of the ADP algorithm is needed for this particular control problem to prevent convergence issues. Finally, a case study is presented to evaluate the effectiveness of flexible power demand, as addressed by the ADP method. The experiment demonstrates a 14.1% improvement in fuel economy compared to a scenario without flexible power demand.

The Effect of a Combination of Ethanol Extract from Leaves and Flowers of Plumeria acuminate L. Against Aedes aegypti Larvae

Aedes aegypti is the primary vector that causes dengue virus (DENV) infection. Ae. aegypti resistance to abate (Temephos) has occurred in Indonesia and several other countries. Innovations are needed to develop alternative ingredients that can be used as natural larvacides. The Plumeria acuminate L. is an Indonesian plant with metabolites that have the potential to act as larvicides. This study aims to determine the potential combination of ethanol extract of P. acuminate L. leaves and flowers as a larvicide for A. aegypti. A laboratory experimental study with a post-test-only control group design was carried out on Ae. aegypti larvae instar III. The larvicide test was carried out according to WHO standards in 2005 with concentrations of 10000, 7500, 5000, and 2500 ppm, as well as control (water and 1% DMSO), with 20 larvae for each concentration. The observation was carried out at the 24th and 48th hours with 3 repetitions. Larval mortality data was analyzed using one-way ANOVA statistical tests to determine significant differences and lethal concentrations (LC50 and LC90) were calculated using probit analysis using SPSS software. The mortality of Ae. aegypti larvae due to the administration of a combined ethanolic extract of P. acuminate L. leaves and flowers was the highest at doses of 10000 and 7500 ppm, which was 100% with lethal concentrations of LC50 and LC90 of 3364.715 and 6293.759 ppm at the 24th hour observation, whereas at the 48th-hour observation, lethal concentrations were detected at 1767.998 and 2941.138 ppm, respectively. One-way ANOVA analysis test showed a significant difference in Ae. aegypti larval mortality due to the administration of a combined ethanol extract of P. acuminate L. leaves and flowers at 24th-hour observation (p = 0.000) and (p = 0.013) at 48th hour observation. The combination of ethanol extract of P. acuminate L. leaves and flowers showed larvicidal activity against Ae. aegypti larvae as evidenced by larvae mortality which were influenced by concentration and observation time.

Variational analysis of sensory feedback mechanisms in powerstroke-recovery systems.

Although the raison d'etre of the brain is the survival of the body, there are relatively few theoretical studies of closed-loop rhythmic motor control systems. In this paper we provide a unified framework, based on variational analysis, for investigating the dual goals of performance and robustness in powerstroke-recovery systems. To demonstrate our variational method, we augment two previously published closed-loop motor control models by equipping each model with a performance measure based on the rate of progress of the system relative to a spatially extended external substrate-such as a long strip of seaweed for a feeding task, or progress relative to the ground for a locomotor task. The sensitivity measure quantifies the ability of the system to maintain performance in response to external perturbations, such as an applied load. Motivated by a search for optimal design principles for feedback control achieving the complementary requirements of efficiency and robustness, we discuss the performance-sensitivity patterns of the systems featuring different sensory feedback architectures. In a paradigmatic half-center oscillator-motor system, we observe that the excitation-inhibition property of feedback mechanisms determines the sensitivity pattern while the activation-inactivation property determines the performance pattern. Moreover, we show that the nonlinearity of the sigmoid activation of feedback signals allows the existence of optimal combinations of performance and sensitivity. In a detailed hindlimb locomotor system, we find that a force-dependent feedback can simultaneously optimize both performance and robustness, while length-dependent feedback variations result in significant performance-versus-sensitivity tradeoffs. Thus, this work provides an analytical framework for studying feedback control of oscillations in nonlinear dynamical systems, leading to several insights that have the potential to inform the design of control or rehabilitation systems.

Immersion and Invariance Adaptive Control through Polynomial Adaptation

Abstract In conventional immersion and invariance (I&I) adaptive control design, control parameter adaptation is typically linear with respect to the parameter-error-induced perturbation, resulting in quadratic-rate dissipation of energy associated with the off-the-manifold variable. Departing from such a convention, this article contributes a novel strategy - polynomial adaptation. As the name suggests, control parameter adaptation in this approach takes the form of a general polynomial in relation to the perturbation. Accordingly, this new design induces polynomial-rate energy dissipation, which is faster than the quadratic one in the conventional scheme, thereby enhancing closed-loop control performance. The theoretical underpinnings of the new approach are demonstrated through the design of an I&I adaptive tracking control law for a general nth-order, single-input-single-output, parametrically uncertain, nonlinear system in the controllable canonical form. Additionally, a numerical study of the proposed method on the second-order forced Duffing oscillator showcases its improved transient performance in comparison to a baseline controller developed with the standard I&I adaptive control technique.

Penerapan Media Pembelajaran Audio Visual Berbasis Canva untuk Meningkatkan Motivasi dan Hasil Belajar Siswa dalam Mata Pelajaran TIK

Mathematics learning activities at SMP Negeri 4 Ciawigebang in general still use textbooks or package books as one of the references used. The school where the research was conducted still uses package books as a learning medium and the method used uses the lecture method, so that in this case Mathematics learning becomes monotonous and less interesting and less motivating to students. This research aims to improve mathematical skills by using Scratch media. The research method used is quantitative with a quasi-experimental type using a research design, namely pretest posttest control design which was carried out at SMP Negeri 4 Ciawigebang. The population used in this study is students in grades 8b and 8e with a total of 54 students. Data collection techniques through observation, tests and questionnaires. The analysis of research data uses a t-test. The results of the analysis showed that there was a change in the improvement of student learning outcomes after the application of scratch learning media to the material of the two-variable linear equation system in mathematics in grade VII of SMP Negeri 4 Ciawigebang

Design and experiment of a crawling-inchworm-type self-tuned dynamic vibration absorber based on silicone gel materials

Based on the different body configurations caused by varying head-to-tail distances exhibited by crawling inchworms during locomotion, this paper proposes a crawling-inchworm-type self-tuned dynamic vibration absorber (DVA) based on silicone gel materials for reducing low-frequency vibration. The proposed DVA was designed and developed by employing a magnetic hanging design with movable features, a span adjustment design with an embedded stepper motor, and a real-time control design using a microcontroller. First, a finite element simulation model was established to analyze the main structure of the self-tuned DVA using the finite element method. The frequency-shifting characteristics of the absorber were obtained by identifying the actuating modes that are sensitive to the hanging span. Second, based on the frequency-shifting characteristics of the self-tuned DVA, an absorber control system was designed by introducing a short-time Fourier transform and PID algorithm to achieve autonomous frequency adjustment of the DVA. Finally, the self-tuned absorption effects of the prototype self-tuned DVA were tested through a series of experiments, which confirmed its excellent self-tuned vibration absorption capability within the low-frequency range.

Design of adaptive barrier function-based backstepping finite time guidance control for interceptor-target systems

This study introduces an optimal finite-time backstepping sliding mode guidance law, leveraging an adaptive continuous barrier function to examine the interceptor-target system’s motion in cylindrical coordinates. The integration of sliding mode and backstepping controllers enhances the robustness and performance of the proposed guidance method amidst external disturbances and model uncertainties. This combination also improves transient response, reduces chattering, and lowers control efforts. The adaptive continuous barrier function employed in this method eliminates the need for prior knowledge of the upper bounds of uncertainties and disturbances. Additionally, it ensures that adaptation gains are not overestimated, leading to more accurate performance and complete elimination of chattering. The Lyapunov stability theory is used to prove the finite-time convergence of the state trajectories of the interceptor-target system to a predefined neighborhood around the origin, despite external disturbances and uncertainties. A genetic optimization algorithm is utilized to optimally select the parameters of the guidance method. The efficacy of the proposed technique is validated through simulation results and real-time experiments on the Baseline Speedgoat Real-Time Target Machine platform. The method’s effectiveness and performance are further demonstrated through analysis and simulation in the MATLAB/Simulink environment.

Design and Experimental Testing of Extended-Range Power Supply System for 15 Horsepower Electric Tractor

Electric tractors have many advantages, including high torque, excellent controllability, energy efficiency, a simple structure, and an electric interface for expansion. However, a significant limitation lies in their endurance. This study presents the design of an extended-range power supply system to ensure continuous endurance for an electric tractor. The objective is to provide a continuous power source for our self-developed electric tractor while preserving the benefits of electric propulsion. Extended-range power systems utilize a primary mover, typically an oil-fueled internal combustion engine, to drive the generator for electricity generation, and the generated AC-form electricity is subsequently converted into stable DC bus voltage by a power electronic converter. The hardware and control design of an extended-range power supply system are finalized and validated through experimental trials. The results demonstrate the system’s capability to sustain stable DC bus voltage amidst disruptions such as sudden load shifts and fluctuations in the prime mover’s speed. Even with a 50% sudden load change, the voltage drop is within 12% and can recover to ±3% within 4 s. The extended-range can be used alone without a battery to power the electric tractor, or it can used in parallel with other extended ranges or batteries for power sharing thanks to the droop control ability.

Fault tolerant control of uncertain hydraulic system against actuator fault based on redesign Lyapunov approach

The design of stabilizing controller for uncertain nonlinear systems with control constraints is a challenging problem. This paper proposes the design of fault tolerant control for a class of uncertain nonlinear systems with actuator faults based on Lyapunov redesign principle. First, an assumption is introduced to design the control of the nominal system. Then, a new control law has been introduced to handle the difficulty caused by actuator failures. It is shown that the actuator faults can be completely compensated by the proposed nonlinear controller. Finally, the method will be applied to a hydraulic system to show its effectiveness.

Nested case–control sampling without replacement

Nested case–control design (NCC) is a cost-effective outcome-dependent design in epidemiology that collects all cases and a fixed number of controls at the time of case diagnosis from a large cohort. Due to inefficiency relative to full cohort studies, previous research developed various estimation methodologies but changing designs in the formulation of risk sets was considered only in view of potential bias in the partial likelihood estimation. In this paper, we study a modified design that excludes previously selected controls from risk sets in view of efficiency improvement as well as bias. To this end, we extend the inverse probability weighting method of Samuelsen which was shown to outperform the partial likelihood estimator in the standard setting. We develop its asymptotic theory and a variance estimation of both regression coefficients and the cumulative baseline hazard function that takes account of the complex feature of the modified sampling design. In addition to good finite sample performance of variance estimation, simulation studies show that the modified design with the proposed estimator is more efficient than the standard design. Examples are provided using data from NIH-AARP Diet and Health Cohort Study.

A new hyperchaotic system: circuit realization, nonlinear analysis and synchronization control

This paper presents a novel seven-dimensional nonlinear hyperchaotic system characterized by a minimal number of nonlinear terms and variables, yet exhibiting high complexity. Standard nonlinear analysis is conducted to unveil the system’s intricacies, emphasizing its notable feature of possessing four to five Lyapunov exponents in certain intervals, signifying its volatility and complexity. Hyperchaotic synchronization is explored using a novel nonsingular terminal sliding control design, effectively achieving synchronization between two hyperchaotic master systems and a hyperchaotic slave system within finite time while mitigating the chattering phenomenon. Practical evaluations through orbital analysis, numerical simulations, and practical implementations further substantiate the efficacy and performance of the proposed system. This study contributes to the advancement of chaotic and hyperchaotic systems, particularly those with dimensions exceeding 5D, offering insights into synchronization techniques and practical applications in engineering and other scientific disciplines.

EFFECT OF GELAM LEAF EXTRACT (Melaleuca cajuputi) AND TRICALCIUM SILICATE CEMENT AS DIRECT PULP CAPPING

Background: Reversible pulpitis is mild pulp inflammation. The treatment is direct pulpcapping. Tricalcium silicate cement has been better at inducing reparative dentin than other materials. Tricalcium silicate cement can cause inflammation 1-2 weeks after application, that natural ingredients need to improve the quality. Tricalcium silicate cement can be combined with galam leaf extract which contains anti-inflammatory properties by accelerating lymphocyte cells. Purpose: To analyzed the effect of gelam leaf extract (Melaleuca cajuputi) concentration of 100% and Tricalcium Silicate Cement on the number of lymphocyte cells on day 3 and 5 in direct pulp capping treatment. Methods: This research is a true experimental study with a post test-only with control design. This study used 24 Wistar rats, divided into 3 treatment groups with 2 different days, namely the group given a combination of Gelam leaf 100% + tricalcium silicate cement, tricalcium silicate cement as positive control, and without treatment as negative control. Results: One-way ANOVA test obtained p value=0.00<0.05, which indicates there is a significant difference between each group. Post Hoc Bonferroni test showed significant difference between galam leaf extract and tricalcium silicate cement, tricalcium silicate cement, and no treatment on days 3 and 5. Conclusion: The combination of galam leaf extract and tricalcium silicate cement can increase the number of lymphocyte cells on day 3 of pulp inflammation and reduce the number of lymphocyte cells on day 5 more effectively than tricalcium silicate cement and without treatment on days 3 and 5 so that the healing process is faster.

TOXICITY TEST OF Eusideroxylon zwageri BARK EXTRACT ON KIDNEY HISTOPATHOLOGY GLOMERULAR HYPERTROPHY AND HYDROPIC DEGENERATION

Background: Ironwood bark extract (Eusideroxylon zwageri) has antioxidant properties such as tannins, phenolics, flavonoids, saponins and alkonoids. Most compounds in the ironwood bark extract were phenolics (31.28 mg GAE/g), flavonoids (30.48 mg CE/g), and proanthocyanidins (183.30 mg PE/g). These can be used as alternative herbal medicines, but also has toxic effects, so a toxicity test is necessary. Toxicity tests can be seen through histopathological parameters based on glomerular hypertrophy and hydropic degeneration. Purpose: To determine the toxic effect of ironwood bark extract administration at doses of 1,250 mg/kg, 2,750 mg/kg, and 4,750 mg/kg orally on the kidneys of Wistar rats based on histopathological appearance of glomerular hypertrophy and hydropic degeneration. Methods: Pure experimental study with a posttest-only with control design, consisting of 4 groups with 3 treatment groups given ironwood bark extract at doses of 1,250 mg/kg, 2,750 mg/kg, and 4,750 mg/kg, and 1 control group was given distilled water 2x1 ml every 24 hours orally for 14 days. Results: In administration of ironwood bark extract at doses of 2,750 mg/kgBW and 4,750 mg/kgBW, glomerular diameter was found increased. The histopathological hydropic degeneration showed a score of 1 in all dose groups. The research data were analyzed using the One Way Anova and Kruskal Wallis tests. Both tests showed no significant differences between groups. Conclusion: There was no toxic effect of ironwood bark extract at doses of 1,250 mg/kg, 2,750 mg/kg, and 4,750 mg/kg on the kidneys of Wistar rats based on histopathological appearance of glomerular hypertrophy and hydropic degeneration.

Intelligent Framework Design for Quality Control in Industry 4.0

This research aims to develop an intelligent framework for quality control and fault detection in pre-production and post-production systems in Industry 4.0. In the pre-production system, the health of the manufacturing machine is monitored. In this study, we examine the gear system of induction motors used in industries. In post-production, the product is tested for quality using a machine vision system. Gears are fundamental components in countless mechanical systems, ranging from automotive transmissions to industrial machinery, where their reliable operation is vital for overall system efficiency. A faulty gear system in the induction motor directly affects the quality of the manufactured product. Vibration data, collected from the gear system of the induction motor using vibration sensors, are used to predict the motor’s health condition. The gear system is monitored for six different fault conditions. In the second part, the quality of the final product is inspected with the machine vision system. Faults on the surface of manufactured products are detected, and the product is classified as a good or bad product. The quality control system is developed with different deep learning models. Finally, the quality control framework is validated and tested with the evaluation metrics.

EFFECT OF GALAM LEAF EXTRACT AND TRI-CALCIUM SILICATE CEMENT ON NEUTROPHIL CELLS IN WISTAR RAT PULP

Background: Pulp capping is a method of sealing the pulp chamber in teeth with cavities that extend to the pulp. Direct pulp capping involves applying a material directly onto the exposed pulp tissue. Tri-calcium silicate cement (Ca3SiO5) is commonly used due to its nanoparticle mineral composition, but it can cause continued inflammation. Galam leaf (Melaleuca cajuputi) is known for its anti-inflammatory properties, owing to secondary metabolites like alkaloids, flavonoids, polyphenols, and saponins, potentially compensating for the drawbacks of tri-calcium silicate cement. Purpose: To determine the effect of combining Galam leaf extract (Melaleuca cajuputi subsp. Cumingiana (Turz) Barlow) with tri-calcium silicate cement as a direct pulp capping material on neutrophil cell count in the pulp of Wistar rats (Rattus norvegicus). Methods: This pure experimental study used a posttest-only control design. Thirty-six Wistar rats were divided into nine groups: one received a combination of 100% Galam leaf extract and tri-calcium silicate cement; one positive control group received tri-calcium silicate cement alone; and one negative control group received direct placement with glass ionomer cement (GIC). The neutrophil cell count was assessed on days 1, 2, and 3. Results: Two-way ANOVA results indicated a significant effect based on treatment and time (p < 0.05). Further analysis with the Post Hoc Bonferroni test (p < 0.05) revealed differences in neutrophil cell counts across nearly all groups on days 1, 2, and 3. Conclusion: The combination of 100% Galam leaf extract and tri-calcium silicate cement significantly reduced neutrophil cell counts compared to both positive and negative control groups on days 1, 2, and 3, indicating anti-inflammatory effect.

Pengaruh Media Wordwall dalam Meningkatkan Minat Belajar Pendidikan Pancasila Siswa Kelas 5 SDN Balekambang 01 Pagi

The aim of this study is to ascertain how the use of Wordwall media by class V students at SDN Balekambang 01 Pagi affects their motivation to pursue Pancasila education. This is a quasi-experimental, quantitative study with a posttest-only control design. For the study, a sample of sixty fifth graders was used. They were divided into two groups: the experimental group used Wordwall, and the control group did not. A questionnaire is used to collect data on students' enthusiasm in learning. The results of the data analysis show that the grade 5 students at SDN Balekambang 01 Pagi's interest for learning about Pancasila Education is greatly impacted by their consumption of Wordwall media. The effect size test demonstrates a modest effect (0.494) and the t test results show that the t value is larger than the t table (2.158 > 2.002). These results provide empirical evidence that Wordwall is a useful tool for stimulating students' interest in Pancasila Education courses.

Neural Operator Approximations for Boundary Stabilization of Cascaded Parabolic PDEs

ABSTRACTThis article proposes a novel method to accelerate the boundary feedback control design of cascaded parabolic difference equations (PDEs) through DeepONet. The backstepping method has been widely used in boundary control problems of PDE systems, but solving the backstepping kernel function can be time‐consuming. To address this, a neural operator (NO) learning scheme is leveraged for accelerating the control design of cascaded parabolic PDEs. DeepONet, a class of deep neural networks designed for approximating nonlinear operators, has shown potential for approximating PDE backstepping designs in recent studies. Specifically, we focus on approximating gain kernel PDEs for two cascaded parabolic PDEs. We utilize neural operators to map only two kernel functions, while the other two are computed using the analytical solution, thus simplifying the training process. We establish the continuity and boundedness of the kernels, and demonstrate the existence of arbitrarily close DeepONet approximations to the kernel PDEs. Furthermore, we demonstrate that the DeepONet approximation gain kernels ensure stability when replacing the exact backstepping gain kernels. Notably, DeepONet operator exhibits computation speeds two orders of magnitude faster than PDE solvers for such gain functions, and their theoretically proven stabilizing capability is validated through simulations.

Optimizing traffic signal control for continuous‐flow intersections: Benchmarking against a state‐of‐practice model

AbstractContinuous‐flow intersections (CFI), also known as displaced left‐turn (DLT) intersections, aim to improve the efficiency and safety of traffic junctions. A CFI introduces additional cross‐over intersections upstream of the main intersection to split the left‐turn flow from the through movement before it arrives at the main intersection which decreases the number of conflict points between left‐turn and through movements. This study develops and examine a two‐step optimization model for CFI traffic signal control design and demonstrates its performance across more than 300 different travel demand scenarios. The proposed model is compared against a state‐of‐practice CFI signal control model as a benchmark. Microsimulation results suggest that the proposed model reduces average delay by 17% and average queue length by 32% for a full CFI compared with the benchmark signal control model.

Effect of Nesting and Swaddling on Sleep Duration of Preterm Neonate Hospitalized at Tertiary Care Centre of Eastern Nepal

Background: All preterm neonates’ sleep is disturbed during hospitalization period due to various stressful environmental factors and human error and without focusing in individual developmental care. This impacts neonatal neurological development as well as normal growth resulting lifelong disabilities. Thus, modification of the environment by intervening developmental care could minimize the iatrogenic effect and neuro-developmental delay by decreasing stressful environment. This study was conducted to assess the effect of nesting and swaddling on sleep duration of preterm neonates during hospitalization at B.P.Koirala Instituted of Health sciences (BPKIHS). Methods: True experimental (post-test control design) study conducted among 36 preterm neonates, admitted in Nursery and Neonatal Unit of BPKIHS. The objective of this study was to assess the effect of nesting and swaddling on sleep duration. Consecutive sampling technique was used for total sample size then after random allocation is applied for creates the samples into two groups: experimental and control. Performa was used to collect socio-demographic characteristics. Sleep duration was recorded in self-administer observation form base on the observational behavior characteristics scoring of neonatal sleep by AASM (American Academy of sleep Medicine). As intervention, nesting and swaddling were performed in experimental group, then the sleep was video-recorded for 2 hours for each neonate. Finally, data were analyzed using descriptive and inferential statistics. Results: Among the enrolled neonates, there were 23 male (63.9%) and 13 female (36.1%) preterm. There was significant difference in sleep duration between experimental and control group. The mean ± SD of sleep duration was 59.22 ± 22.61 minute in experimental group and 39.50 ± 8.06 minute in control with p-value 0.001. The mean sleep duration was not associated with other selected study variables except the performed intervention. Conclusions: Nesting and Swaddling can be used as convenient and effective method to increase neonatal sleep duration or rest period.