Behavior Of Control System Research Articles

A Review on Cascaded Linear Quadratic Regulator Control of Roll Autopilot Missile

The missile roll control system is considered based on design of autopilot that controls the roll angle of a missile. The Linear Quadratic Regulator Controller (LQR) is involved in controlling the roll angle of missile autopilot system. The roll controllers are represented in the second order time domain system and the results of LQR control is distinguished with the results of sliding mode control (SMC) and Fuzzy logic controller (FLC). Then, the behaviour of roll control systems is analysed to decide which controller gives better performance result with respect to the desired roll angle. As per the literature survey analysis, it is clear that LQR controller deliver the best performance than sliding mode controller and fuzzy logic controller. In the design of a missile roll control of an autopilot LQR is most convincingly employed. The stable performance characteristics are obtained by decoupling the dynamics of missile roll. The assessment on the effective stabilization of the missile autopilot in a practical model is discussed in this paper. Linear quadratic regulator exhibits the better effectiveness than the Fuzzy Logic Controller and Sliding Mode Control.

Pseudochaotic behavior of deterministic automatic control systems of technical devices

А method for generating a pseudo-random response in a linear dynamic system is considered. An example of the system transition to pseudochaotic behavior is given. The calculation of fatigue loads in the toggle plate by the given method is presented. The advantage of this method in calculating fatigue loads is shown.

Self-Tuning of Adaptive Backstepping Control for Reference Tracking

Abstract This paper presents a nonlinear control approach based on backstepping techniques for a high-speed linear axis driven by pneumatic artificial muscles (PAMs). Its guided carriage is actuated by a nonlinear drive system consisting of two pulley tackles with PAMs mounted at both sides. This allows for an increased workspace as well as higher carriage velocities as compared to a direct actuation. The proposed control scheme has a cascaded structure, where backstepping control concepts are used for a fast inner pressure control loop as well as an outer position control. Hysteresis of the PAMs is not modelled directly but counteracted by an additional adaptive parameter in the outer control loop. The main contribution of this paper is the investigation of a self-tuning algorithm that optimises the controlled system behaviour. Based on several criteria, the gradient of an evaluation cost function (ECF) w.r.t. the control design parameters is approximated and used for an optimisation. Two different variants of the self-tuning adaptive backstepping control are compared with each other using realistic simulations of a given test rig. The obtained results show an excellent closed-loop performance after tuning – compared with the initial design.

Socio-Organo Complexity, Project Schedule Performance and Underdamped Transient Motion

Complexity is an inherent property of all systems and a result of interconnections. In projects various systems come together to deliver the required outcome(s). The most common type of project complexity mentioned / considered in practice is the technical complexity and this has always been considered a main factor which affects project performance. Despite that, projects are delivered by people who interface ontinuously and therefore are effected by complexity, and in particular that caused by socio-organo interfaces and the boundaries between the various teams and parties. This has not been investigated. ocio-organo complexity leads to reduction in performance if interconnections are not managed. Research has been carried out to understand the effects of complexity through project management processes on project schedule and performance, aiming towards the development of a tool and identification of actions that will enable the management of these effects. The author presents results of five case studies, which demonstrate that socio-organo complexity affects performance and these results have similarities with the behaviour of underdamped control systems. The results have significant implications on the way socioorganisational complexity can be managed, how processes are implemented, but also enable parallels to be drawn between the fields of project management and control systems. Considering control systems theory proposals are made in this paper for actions to be taken which will contribute towards the management of the effects of socio-organo complexity on projects.

Are Yellow Sticky Cards and Light Traps Effective on Tea Green Leafhoppers and Their Predators in Chinese Tea Plantations?

Simple SummaryLeafhoppers are serious insect pests in agriculture across the world. Both nymphs and adults suck the sap of plant shoots and leaves with their piercing–sucking mouthparts causing damage called “hopperburn”. The tea green leafhopper, Empoasca onukii, is one of most damaging pests in tea plantations in Asia. In China, yellow sticky cards and light traps are increasingly used to control leafhoppers in tea plantations, especially the tea green leafhopper. Visually, several leafhoppers appear to be captured and killed, however, the real control efficiency and the damage to natural enemies remains unclear. In our study, a 16-week open field experiment with daily weather monitoring was designed to test the responses of tea green leafhopper, parasitoids and spiders to yellow sticky cards and light traps (cover with sticky cards) that used different light colours. An exclosure experiment was also designed to further test the influence of the three light systems (without sticky card) on the same groups of species. The results suggested that light, especially green and white, can be useful as a way to control leafhopper populations without affecting parasitoids and spiders too much.In Chinese tea plantations, yellow sticky cards and light traps are increasingly used to control insect pests, especially the tea green leafhopper Empoasca onukii. In this study, a 16-week open-field experiment with daily weather monitoring was designed to test the responses of tea green leafhopper, parasitoids and spiders to yellow sticky cards and three light traps with different wavelengths (covered with sticky cards). An exclosure experiment was also designed to further test the influence of the three light systems (without sticky card) on the same species. The results showed that all three light emitting diode (LED) light traps (white, green and yellow) and yellow sticky cards attracted many more E. onukii male adults than females during the course of the open field experiment, with less than 25% of trapped adults being females. Parasitoids and spiders were also attracted by these systems. Weather variables, especially rainfall, influenced the trapping efficiency. In the exclosure experiment, the population of leafhoppers in the yellow sticky card treatment did not decline significantly, but the number of spiders significantly decreased. The green and white light treatments without sticky cards showed a significant control of E. onukii and no obvious harm to spiders. These results suggest that yellow sticky cards and light traps have limited capacity to control tea green leafhoppers. However, light, especially green light, may be a promising population control measure for tea green leafhoppers, not as killing agents in the traps, but rather as a behavioral control system.

FAKTOR-FAKTOR YANG MEMPENGARUHI KECENDERUNGAN KECURANGAN AKUNTANSI DENGAN KOMITMEN ORGANISASI SEBAGAI VARIABEL INTERVENING

The purpose of this study was to analyze the influence of the Government Internal Control System, Compliance with Accounting Rules, Law Enforcement and Unethical Behavior on the Tendency of Accounting Fraud with Organizational Commitment as an Intervening Variable in Bengkalis Regency. The population in this study was OPD in the Riau Provincial Government. The sample in this study were officials or employees involved in financial management / accounting at OPDs in Bengkalis Regency, amounting to 35 OPDs with 105 respondents. The sampling method is saturated sampling method or census. The data collection method is a survey method. Data analysis using SEM using SMART PLS. The results showed that the government's internal control system, regulatory compliance, law enforcement and unethical behavior had an effect on the tendency of accounting fraud. Organizational commitment is an intervening variable between the government's internal control system, compliance with accounting rules and adherence to accounting rules and the tendency of accounting fraud, but organizational commitment is not an intervening variable between unethical behavior and the tendency of accounting fraud.

Convolutional Multi-Spike Neural Network as Intelligent System Prediction for Control Systems

The evolution in the field of Artificial Intelligent (AI) with its training algorithms make AI very important in different aspect of the life. The prediction problem of behavior of dynamical control system is one of the most important issue that the AI can be employed to solve it. In this paper, a Convolutional Multi-Spike Neural Network (CMSNN) is proposed as smart system to predict the response of nonlinear dynamical systems. The proposed structure mixed the advantages of Convolutional Neural Network (CNN) with Multi -Spike Neural Network (MSNN) to generate the smart structure. The CMSNN has the capability of training weights based on a proposed training algorithm. The simulation results demonstrated that the proposed structure has the ability to predict the response of dynamical systems more powerful than with the CNN. The proposed structure is more powerful than the CNN by 28.33% in terms of minimizing the root mean square error.

Identification and optimization of CNC dynamics in time-dependent machining processes and its validation to fluid jet polishing

In time dependent CNC processes such as polishing, a target material removal profile is obtained by creating and inputting G-codes with varying feed into the controller of a machine tool. The input G-codes are firstly filtered by a CNC interpolator, and the real-time generated signal then goes to a feed drive system of the machine. Through these steps, the original signal is distorted and the ideal feed profile cannot be achieved in some areas. This distortion affects the material removal distribution, and thus the accuracy of the final polished surface profile. While a number of methods have been developed for predicting polished surfaces, most of them fail to consider the influence of controller dynamics. In this paper, a method for accurate prediction of polished surfaces is proposed that considers the error contribution from control signal distortion, and a strategy for compensation of this error. Firstly, the principles of identification of control system behavior in a machine tool are explained, and a process model for Fluid Jet Polishing (FJP) is introduced. Secondly, the transfer functions of the control system are identified, and the process model calibrated against experimental data. Thirdly, a simulator for predicting polished surface profiles is implemented that combines the control system and process model. A micro-groove polishing experiment is carried out that validates the reliability of the proposed method, and shows its limitations. Finally, an algorithm based on particle swarm optimization is proposed for reducing the impact of controller dynamics in micro-groove polishing.

Control Scheme of a Bidirectional Inductive Power Transfer System for Electric Vehicles Integrated into the Grid

Inductive power transfer (IPT) systems have become a very effective technology when charging the batteries of electric vehicles (EVs), with numerous research works devoted to this field in recent years. In the battery charging process, the EV consumes energy from the grid, and this concept is called Grid-to-Vehicle (G2V). Nevertheless, the EV can also be used to inject part of the energy stored in the battery into the grid, according to the so-called Vehicle-to-Grid (V2G) scheme. This bidirectional feature can be applied to a better development of distributed generation systems, thus improving the integration of EVs into the grid (including IPT-powered EVs). Over the past few years, some works have begun to pay attention to bidirectional IPT systems applied to EVs, focusing on aspects such as the compensation topology, the design of the magnetic coupler or the power electronic configuration. Nevertheless, the design of the control system has not been extensively studied. This paper is focused on the design of a control system applied to a bidirectional IPT charger, which can operate in both the G2V and V2G modes. The procedure design of the control system is thoroughly explained and classical control techniques are applied to tailor the control scheme. One of the advantages of the proposed control scheme is the robustness when there is a mismatch between the coupling factor used in the model and the real value. Moreover, the control system can be used to limit the peak value of the primary side current when this value increases, thus protecting the IPT system. Simulation results obtained with PSCADTM/EMTDCTM show the good performance of the overall system when working in both G2V and V2G modes, while experimental results validate the control system behavior in the G2V mode.

Association between childhood trauma and risk for obesity: a putative neurocognitive developmental pathway

BackgroundChildhood trauma increases the risk for adult obesity through multiple complex pathways, and the neural substrates are yet to be determined.MethodsParticipants from three population-based neuroimaging cohorts, including the IMAGEN cohort, the UK Biobank (UKB), and the Human Connectome Project (HCP), were recruited. Voxel-based morphometry analysis of both childhood trauma and body mass index (BMI) was performed in the longitudinal IMAGEN cohort; validation of the findings was performed in the UKB. White-matter connectivity analysis was conducted to study the structural connectivity between the identified brain region and subdivisions of the hypothalamus in the HCP.ResultsIn IMAGEN, a smaller frontopolar cortex (FPC) was associated with both childhood abuse (CA) (β = − .568, 95%CI − .942 to − .194; p = .003) and higher BMI (β = − .086, 95%CI − .128 to − .043; p < .001) in male participants, and these findings were validated in UKB. Across seven data collection sites, a stronger negative CA-FPC association was correlated with a higher positive CA-BMI association (β = − 1.033, 95%CI − 1.762 to − .305; p = .015). Using 7-T diffusion tensor imaging data (n = 156), we found that FPC was the third most connected cortical area with the hypothalamus, especially the lateral hypothalamus. A smaller FPC at age 14 contributed to higher BMI at age 19 in those male participants with a history of CA, and the CA-FPC interaction enabled a model at age 14 to account for some future weight gain during a 5-year follow-up (variance explained 5.8%).ConclusionsThe findings highlight that a malfunctioning, top-down cognitive or behavioral control system, independent of genetic predisposition, putatively contributes to excessive weight gain in a particularly vulnerable population, and may inform treatment approaches.

New trends in modeling and control of hybrid systems

New trends in modeling and control of hybrid systems

Robustness Improvement of Model-Based Sensorless SPMSM Drivers Based on an Adaptive Extended State Observer and an Enhanced Quadrature PLL

Conventional model-based sensorless surface-mounted permanent magnet synchronous motor (SPMSM) drivers suffer deteriorated performance in transient-state operation such as accelerating during wide-speed range or encountering large load torque disturbance. In this article, an effective sensorless control solution is proposed to improve the robustness of sensorless SPMSM drivers in transient-state operation. Two extended state observers (ESOs) are utilized to estimate the αβ-axis back electromotive forces (EMFs). An adaptive bandwidth tuning scheme is proposed to online tune the parameters of the ESOs, with which the desired estimation performance of back EMFs can be achieved in wide-speed operation range. Additionally, the dynamic mechanical behavior of the sensorless control system during large load torque transient is investigated by using small-signal analysis, and then a corresponding speed estimation compensation scheme for the conventional quadrature phase-locked loop (QPLL) is developed, with which the capability of QPLL in tracking the rapidly changing speed can be significantly enhanced. Experiments on an SPMSM demonstrate the superior robustness of the proposed method to that of the conventional method in transient-state operation.

Numerical solution of two-dimensional nonlinear fuzzy delay integral equations via iterative method and trapezoidal quadrature rule

In recent years, fuzzy delay integral equation has received a considerable amount of attention. From the viewpoint of engineering, time delays in controllers may induce complex dynamic behavior and will limit the performance of the active control. Therefore, time delays play an important role in the dynamic behavior of active control systems. In our paper, we introduce an iterative method using trapezoidal quadrature formula for solving two-dimensional nonlinear fuzzy delay integral equations. In addition, the existence and uniqueness of the solution of these equations are proved. Also, the convergence analysis and a criterion to stop of the presented method are investigated. Moreover, we prove numerical stability analysis of the method through choosing the perturbation in the first iteration. Eventually, some numerical examples are provided to demonstrate the applicability of this procedure.

ANALISIS FAKTOR DETERMINAN TERJADINYA KECENDERUNGAN KECURANGAN (STUDI PADA PEMERINTAH PROVINSI PAPUA)

The study conducted to examine the effects of compensation suitability, leadership authority, internal control system, information asymmetric, regulatory enforcement and moral reasoning to the fraud tendency—unethical behaviour used as mediating variable. I raised the data using a survey. The data is analyzed using WrapPLS 6.0 application. The result shows that the leading authority and moral reasoning have an effect on the tendency of fraud, while compensation suitability, internal control system, information asymmetry, regulatory enforcement, and unethical behaviour has no effect. Furthermore, unethical behaviour does not mediate the compensation suitability, leadership authority, internal control system, information asymmetry, regulatory enforcement, and moral reasoning.

Control trajectory optimisation and optimal control of an electric vehicle HVAC system for favourable efficiency and thermal comfort

In order to increase the driving range of battery electric vehicles, while maintaining a high level of thermal comfort inside the passenger cabin, it is necessary to design an energy management system which optimally synthesizes multiple control actions of heating, ventilation and air-conditioning (HVAC) system. To gain an insight into optimal control actions and set a control benchmark, the paper first proposes an algorithm of dynamic programming (DP)-based optimisation of HVAC control variables, which minimises the conflicting criteria of passenger thermal comfort and HVAC efficiency. Next, a hierarchical structure of thermal comfort control system is proposed, which consists of optimised low-level feedback controllers, optimisation-based control allocation algorithm that sets references for the low-level controllers, and a superimposed cabin temperature controller that commands the cooling capacity to the allocation algorithm. Finally, the overall control system is verified by simulation for cool-down scenario, and the simulation results are compared with the DP benchmark. The results show that the control system behaviour can approach the DP benchmark if the superimposed controller bandwidth is tuned along with the allocation cost function weighting coefficients, where a fast controller tuning relates to better thermal comfort while a slow tuning results in improved efficiency.

Modified rotor-side converter control design for improving the LVRT capability of a DFIG-based WECS

The rapid integration of wind-power generation with existing power grids has caused reliability and stability concerns owing to the negative impact on the dynamic behaviors of power systems. During a fault, large electromotive force is induced in the rotor circuit of a doubly fed induction generator (DFIG) as the circuit is highly vulnerable to it. Such circumstances increase the importance of the low-voltage ride-through (LVRT) capability of a DFIG to ensure stability of the electric grid during transient conditions. Considering these factors, this study focuses on the mitigation of rotor overcurrents and DC-link voltage variations by modifying the control structure of the DFIG converter, thereby enhancing its LVRT capability. Additional voltage terms are injected into the rotor-voltage references to improve the transient behavior of the DFIG control system. In the proposed design, transient rotor currents and DC-link voltage variations are effectively suppressed. Because the voltage terms are introduced outside the current loops, there is no impact on their stability. Furthermore, electromagnetic torque oscillations during the faults are considerably suppressed. Finally, the validity of the proposed design during abnormal grid conditions is demonstrated via MATLAB/Simulink. The results confirm the feasibility and effectiveness of the improved converter control design to enhance the LVRT capability of a DFIG.

Study and Comparison of Seismic Behaviour of Isolator-Damper Hybrid Control System with Conventional Structural Systems

In this paper, in addition to introduce a hybrid structural system contained local isolators and dampers, its behavior and functional capabilities were studied on a conventional structure. For this purpose, an RC frame building with six-story was designed based on valid codes and then, in four cases based on the number of spans, it was split into two separate adjacent frames. Base isolation was done underneath the columns of one frame, while the bottom connections of the other frame’s columns were remained fixed and viscous dampers provided the connection of two adjacent frames on the same floors. Nonlinear time history analysis (NTHA) under three near-fault and three far-fault earthquakes and frequency-domain analysis are performed. Displacement, drift, acceleration and shear forces of the stories in the four proposed hybrid cases with two limited cases, full base-isolated and full base-fixed frames, as well as nonlinear hysteresis behavior of a damper and an isolator are assessed. The results showed that using the novel hybrid control method in most cases can mitigate deteriorating effects of all types of seismic motions observed in the conventional structural systems. However, among them, two cases (2 isolated columns -5 fixed columns and 3 isolated columns -4 fixed columns) had the best significant influence on seismic performance and structural response reduction. Furthermore, frequency response functions of displacement and acceleration with respect to ground acceleration demonstrated that the two proposed cases further suppress the responses of the limited cases, over a wide range of frequencies including all natural frequencies. Due to decrease about 50-70% in the number of base isolators (compared to full isolation) lead to considerable construction cost savings. In spite of the limitation of ASCE7-10 code on separately using base isolators and dampers on structure, applying the proposed combination technique of these two dissipating devices can overcome the limitation.

Reinforcement learning-based detection method for malware behavior in industrial control systems

Due to the popularity of intelligent mobile devices, malwares in the internet have seriously threatened the security of industrial control systems. Increasing number of malware attacks has become a major concern in the information security community. Currently, with the increase of malware variants in a wide range of application fields, some technical challenges must be addressed to detect malwares and achieve security protection in industrial control systems. Although many traditional solutions have been developed to provide effective ways of detecting malwares, some current approaches have their limitations in intelligently detecting and recognizing malwares, as more complex malwares exist. Given the success of machine learning methods and techniques in data analysis applications, some advanced algorithms can also be applied in the detection and analysis of complex malwares. To detect malwares and consider the advantages of machine learning algorithms, we developed a detection framework for malwares that threatens the network security of industrial control systems through the combination of an advanced machine learning algorithm, i.e., reinforcement learning. During the implementation process, according to the actual needs of malware behavior detection, key modules including feature extraction, policy, and classification networks were designed on the basis of the intelligent features of reinforcement learning algorithms in relation to sequence decision and dynamic feedback learning. Moreover, the training algorithms for the above key modules were presented while providing the detailed functional analysis and implementation framework. In the application experiments, after preprocessing the actual dataset of malwares, the developed method was tested and the satisfactory classification performance for malware was achieved that verified the efficiency and effectiveness of the reinforcement learning-based method. This method can provide an intelligent decision aid for general malware behavior detection.

Searching for Complexity in the Human Pupillary Light Reflex

This article aims to examine the dynamical characteristics of the pupillary light reflex and to provide a contribution towards their explanation based on the nonlinear theory of dynamical systems. To introduce the necessary concepts, terminology, and relevant features of the pupillary light reflex and its associated delay, we start with an overview of the human eye anatomy and physiology with emphasis on the iris, pupil, and retina. We also present the most highly regarded models for pupil dynamics found in the current scientific literature. Then we consider the model developed by Longtin and Milton, which models the human pupillary light reflex, defined by a nonlinear differential equation with delay, and present our study carried out on the qualitative and quantitative dynamic behavior of that neurophysiological control system.

Impact of Behavioral Safety (Behavioural-Based Safety – BBS) on the Modification of Dangerous Behaviors in Enterprises

Abstract In enterprises, accidents happen mainly due to improper and dangerous behavior of employees. The approach called Behavioral Safety (BBS) assumes that the most effective attempts to modify dangerous employee behavior are based on influencing people abuse. As a consequence, change in behavior leads to a change in the way of thinking and attitude. In the other words, as a result of using behavioral methods for a long time, employees create a safe attitude that in the future translates into further safe behavior. Mutual control of employees during work is not accepted in Poland and positively perceived by participants of the work process. It is difficult to change the mentality and habits of people. Increasingly, employee behavior control systems are implemented in medium and large enterprises. Shaping a positive attitude of the employee to such systems and methods is a long and time-consuming work that lies with the employer and OSH supervisor. Presented studies have shown that a fairly large proportion of employees do not understand the positive effects of using behavioral safety methods. There is a great need to shape awareness of safe behaviors among Polish employees using behavioral safety, i.e. safety based on mutual observation of behaviors. This paper contains the results of the first stage of the study aimed at modifying undesirable behavior among employees using the implemented BBS system.