High Precision Height Control for Wing-in-Ground Crafts

In particular, it is useful to pay attention to control strategies to reduce energy consumption. In this article, the purpose is to regulate and control the temperature and humidity of the air in a room with specific dimensions. The dynamical equations of the HVAC system are presented as equations of temperature and humidity variation. A control system based on LQR optimal control method is designed for this air conditioning system including two heating and cooling operations. Then, after examining the stability of the system based on the Lyapunov stability criterion, and also a temperature control performance index is defined to express and compare the performance of control system with different gains. Finally, by performing the simulation, the control and HVAC system performance is evaluated with the help of defined performance index in the presence of designed algorithm which results show that LQR gains have direct effect on energy consumption and control system performance.

In the field of civil engineering, magnetorheological fluid (MRF) damper-based semi-active control systems have received considerable attention for use in protecting structures from natural hazards such as strong earthquakes and high winds. In this paper, the MRF damper-based semi-active control system is applied to a long-span spatially extended structure and its feasibility is discussed. Meanwhile, a trust-region method based instantaneous optimal semi-active control algorithm (TIOC) is proposed to improve the performance of the semi-active control system in a multiple damper situation. The proposed TIOC describes the control process as a bounded constraint optimization problem, in which an optimal semiactive control force vector is solved by the trust-region method in every control step to minimize the structural responses. A numerical example of a railway station roof structure installed with MRF-04K dampers is presented. First, a modified Bouc-Wen model is utilized to describe the behavior of the selected MRF-04K damper. Then, two semi-active control systems, including the well-known clipped-optimal controller and the proposed TIOC controller, are considered. Based on the characteristics of the long-span spatially extended structure, the performance of the control system is evaluated under uniform earthquake excitation and travelling-wave excitation with different apparent velocities. The simulation results indicate that the MR fluid damper-based semi-active control systems have the potential to mitigate the responses of full-scale long-span spatially extended structures under earthquake hazards. The superiority of the proposed TIOC controller is demonstrated by comparing its control effectiveness with the clipped-optimal controller for several different cases.

Present study aimed to analysis whether delegation of authority and changes in control and management accounting systems, adjusts or increases the relationship between competition and corporate performance. Study Population is companies listed in Tehran Stock Exchange and needed data is gathered from questionnaire and financial statements. Excel software used to category information and for testing hypothesis statically software was used. Results show that there is a positive and meaningful relationship between competition power and management delegation of authority, change in control systems and management accounting system and corporate performance and changes in control and management accounting systems. Results also show that there is relationship between delegation of authority with variables like control and management accounting systems changes and corporate performance. Other results explain that there is meaningful relationship between changes in control and management accounting systems with corporate performance of management.

The field-oriented control (FOC) strategy of a permanent magnet synchronous motor (PMSM) in a simplified form is based on PI-type controllers. In addition to their low complexity (an advantage for real-time implementation), these controllers also provide limited performance due to the nonlinear character of the description equations of the PMSM model under the usual conditions of a relatively wide variation in the load torque and the high dynamics of the PMSM speed reference. Moreover, a number of significant improvements in the performance of PMSM control systems, also based on the FOC control strategy, are obtained if the controller of the speed control loop uses sliding mode control (SMC), and if the controllers for the inner control loops of id and iq currents are of the synergetic type. Furthermore, using such a control structure, very good performance of the PMSM control system is also obtained under conditions of parametric uncertainties and significant variations in the combined rotor-load moment of inertia and the load resistance. To improve the performance of the PMSM control system without using controllers having a more complicated mathematical description, the advantages provided by reinforcement learning (RL) for process control can also be used. This technique does not require the exact knowledge of the mathematical model of the controlled system or the type of uncertainties. The improvement in the performance of the PMSM control system based on the FOC-type strategy, both when using simple PI-type controllers or in the case of complex SMC or synergetic-type controllers, is achieved using the RL based on the Deep Deterministic Policy Gradient (DDPG). This improvement is obtained by using the correction signals provided by a trained reinforcement learning agent, which is added to the control signals ud, uq, and iqref. A speed observer is also implemented for estimating the PMSM rotor speed. The PMSM control structures are presented using the FOC-type strategy, both in the case of simple PI-type controllers and complex SMC or synergetic-type controllers, and numerical simulations performed in the MATLAB/Simulink environment show the improvements in the performance of the PMSM control system, even under conditions of parametric uncertainties, by using the RL-DDPG.

Uncertainty is an inherent characteristic of actual control systems since their parameters are not fixed and may change based on external factors. The behaviour and performance of control systems can be strongly impacted by these unknown characteristics. Variability in the environment, ageing of core components, and manufacturing tolerances are some of the factors that contribute to this uncertainty and pose an unknown risk to control systems. As a result, real control systems' intrinsic parameter indeterminacy may have an impact on how well they operate. Real-life scenarios are often ambiguous and complex, posing challenges for decision-makers to articulate their opinions. Neutrosophic sets are employed in such contexts to handle indeterminacy effectively. Neutrosophic theory suggests a variable interval based on truth, indeterminacy, and falsity, allowing for the expression of both determinate and indeterminate information. Nevertheless, neutrosophic sets have not yet been used in the modelling, analysis, and design of uncertain control systems with determinate parameters. To close this gap, a new neutrosophic design technique is established in this study by introducing single-valued neutrosophic systems. The suggested control design method is illustrated with a numerical example employing neutrosophic parameters.

This paper aims to focus on database configuration of process control systems during project engineering phase and the impact of initial configuration on their performances and lifetime. We will start by highlighting operation principle of such systems, taking as example DCS systems (Distributed Control Systems) where we discussed their hardware and software architecture evolution and then identify the most common problems encountered on these systems. Through a case study, we will focus on the optimization of database configuration and see how could bad configuration practices reduce the control system performances and then may affect industrial process operation. The case study discussed is about a DCS system installed to control oilfield processing facilities where hardware and software description on this control system is given. We will emphasize on system deficiencies which the most important of them is the problem of database memory saturation which causes significant system performances and lifetime decreases.KeywordsProcess control system (PCS)Distributed control system (DCS)Database configurationMemory saturationSystem performance and lifetime

Distributed control and optimization form the backbone of many critical control systems, with typical examples including sensor networks, power grids, and intelligent transportation systems. As these systems grow in scale and complexity, ensuring the privacy of individual agents becomes increasingly essential. Privacy protection is no longer an optional add-on; it is a crucial element in the design of these systems. Sensitive data, such as states, measurements, and decisions, must be shielded from unauthorized access or malicious attacks, while still allowing the system to function effectively. This special issue aims to explore novel techniques and strategies that protect privacy in distributed control and optimization, showcasing how these approaches can be seamlessly integrated into real-world applications. The diverse contributions in this issue demonstrate the growing importance of privacy in the evolving field of distributed control systems. RNC7747 introduces a privacy-preserving method for coverage control in multi-agent systems with limited communication ranges, ensuring efficient operation without compromising agents' privacy. RNC7798 proposes a privacy-preserving consensus mechanism based on pulse-coupled oscillators, helping maintain privacy while agents coordinate in distributed networks. RNC7778 presents privacy preservation techniques for cloud-based cooperative LQG control systems, enabling privacy protection even when leveraging cloud resources. RNC8051 discusses achieving privacy-preserving average consensus in unreliable network environments, ensuring privacy despite communication challenges. RNC7929 introduces a novel approach to open privacy-preserving consensus via state decomposition, allowing agents to reach consensus while maintaining privacy. RNC7966 investigates leader-follower consensus in multi-agent systems with distributed event-triggered observations, ensuring privacy during agent coordination in real-time systems. RNC7789 discusses the tradeoff between privacy protection strength and control performance in control systems. RNC8029 proposes a new privacy mechanism for distributed average consensus on time-varying directed graphs. RNC7776 investigates event-triggered distributed optimization with differential privacy, reducing communication costs while safeguarding sensitive data. RNC7885 develops an event-triggered privacy-preserving optimization method for directed communication networks, emphasizing privacy during optimization tasks. RNC7791 focuses on robust optimization for virtual power plant scheduling under uncertainty, incorporating privacy preservation into the optimization process. RNC7730 explores prescribed-time distributed optimization with set constraints, offering time guarantees while maintaining privacy in dynamic optimization scenarios. RNC7926 provides a privacy-preserving algorithm for constrained resource allocation with communication delays, crucial for real-time decision-making in distributed systems. RNC7848 presents an adaptive event-triggered control strategy for cyber-physical systems under DoS and deception attacks, ensuring privacy and system security. RNC8068 addresses initial state privacy in nonlinear systems on Riemannian manifolds, offering methods to protect privacy in complex, high-dimensional control systems. RNC7906 focuses on dynamic consensus-based formation control for multi-robot systems, preserving privacy through output masking techniques while achieving coordination. RNC7688 introduces a periodic dynamic encoding mechanism for stealthy attack detection in distributed state estimation, focusing on security and privacy under attack scenarios. RNC70033 tackles robust consensus Kalman filtering for distributed state-saturated systems, incorporating dynamic-disturbed saturation levels and censored measurements to ensure privacy under uncertain conditions. The contributions in this special issue span a broad spectrum of topics related to privacy in distributed control and optimization. As distributed systems continue to evolve, these papers contribute to the ongoing conversation about balancing privacy protection with efficient system operation, highlighting the importance of privacy as a key consideration in the design and optimization of future distributed control systems. The authors declare no conflicts of interest.

A set of indices to assess the real performance of daylight-linked control systems

In this paper, a theoretical investigation of improving the performance of automatic control systems with random inputs by using nonlinear characteristics is described. If the statistical characteristics of random inputs are known, an optimum nonlinear characteristic can be introduced in order to minimize the mean squared value of the error signal in the system. Proceeding from the analytical procedure derived previously by the authors, a method of obtaining the optimum nonlinear characteristics is shown in detail. It has been applied to the interesting practical cases of automatic control systems for the random inputs with a typical auto-correlation function. That is, the optimum nonlinear characteristic has been obtained for the following two cases : (1) the case of a control system with a Gaussian random disturbance ; (2) the case of a control system with a Gaussian random signal contaminated by random noise. The procedure is also summarized in the final section.

The control performance of hydraulic systems is basically influenced by the performance of the electro-hydraulic servo valve incorporated in a hydraulic control system. In this study, the authors propose a control design to improve the control performance of a servo valve with a non-contact eddy current type position sensor. A mathematical model for the valve is obtained through an experimental identification process. A PI-D control together with a feedforward (FF) control is applied to the valve. To further improve the dynamic response of the servo valve, an input shaping filter (ISF) is incorporated into the valve control system. Finally, the effectiveness of the proposed control system is verified experimentally.

Aerodynamic characteristics of an airfoil, NACA 6409, flying over a wavy wall is investigated numerically. An Euler code based on the LU-factored algo rithm and higher-order upwind scheme is constructed and its accuracy is tested on two benchmark problems : NACA 4412 airfoil moving over a level ground and NACA 0012 airfoil in free-flight pitching oscillation. The calculated flow about NACA 6409 airfoil over the wavy ground represented by a moving sine function indicates that the aerodynamic property of the airfoil becomes sensitive if the wave number or amplitude of the wavy ground is increased, and/or if the proximity of the airfoil to the ground is smaller. Introduction When an aircraft flies near the ground, the aerodynamic performance of the wing is much changed from that of the free flight. In particular, a wing in proximity to the ground manifests reduced upwash, downwash, and tip vortices which cause enhancement of lift and pitching moment, and reduction of induced drag. These effects, in overall, are called ‘the ground effect’ whereas the wing taking advantage of these effects is called ‘wing in the ground effect’ or WIG, in short. There has been recently considerable interest in development of WIG crafts in such countries as Russia[1,2], Japan[3,4], Germany[5,6], and China[7] due to its energy saving feature as a means of passenger and cargo transportation. Preliminary design of a WIG airplane is under progress in South Korea[8] and the present research is motivated by this particular program. The gain in the lift-todrag ratio might be achieved by a WIG craft at the cost of stability due to the increased pitching moment. The flight properties of a WIG hence need to be investigated thoroughly during the aircraft development process. Recently, a few reports have appeared on the aerodynamic performance of WIG wings and airfoils[4-7,9] flying over a level *Doctoral candidate, Dept. of Aerospace Engineering. tprofessor, Dept. of Aerospace Engineering, Member AIAA. Copyright @ 2000 by YEHOO” Im. Kcun-Shik Chmg. Publidld by the Americ-n Institute of Aeronautica md Aatronautica. Inc. with permhion. ground. NACA Cdigit airfoils are, in general, known to have positive ground effect. However, a symmetric airfoil with large thickness, NACA 0012, for example, can exhibit negative ground effect at a small angle of attack[4,7]. The WIG craft operated over the sea is quite often expected to face with rough wavy surfaces. This rather periodic terrain will cause ground effect different from that of the level ground. In the literature, the unsteady flow past a twodimensional airfoil moving over a wavy ground has been investigated with the lifting surface theory by Ando et al.[lO], and with the unsteady panel method by Morishita and Ashihara[ll]. Mizutani and Suzuki[l2] used Rankine source and boundary element method to compute the wing aerodynamics over the coastal free surface. Their results have certainly offered some useful data for fundamental study of the lifting airfoils. However, the solutions of Euler and Navier-Stokes equations are still wanted in order to study the possible compressibility and viscosity effect of the WIG craft. In this paper we have numerically solved the Euler equations with the LU-factored algorithm[l3] and high-resolution upwind scheme for the unsteady WIG airfoil moving over a wavy wall. Fortunately, Mizutani and Suzuki[l2] have found that deformation of the free surface caused by the proximate flight of a WIG craft is only negligible. We verified accuracy of the present computer code by reproducing two earlier results : NACA 4412 airfoil over a level ground[l4], and the NACA 0012 airfoil in pitching oscillation[l5]. Various parameter effects on NACA 6409 airfoil flying over a wavy wall with a subsonic flight Mach number, M, = 0.3, is elaborated in this paper. Governing Equations We consider unsteady twodimensional Euler equations in the computational domain (t, 5, n), 1 OF 8 aQ ai aF z+-+-=O ac 877 with the flux vectors (1) AMERICAN INSTITUTE OF AERONAUTICS AND ASTRONAUTICS PAPER 2000-0657

Researching optimization problems of controller is need of industrial process control ,in which PID controller is widely used,which its parameters can be equivalent to optimization problems. In the industrial control the PID controller is widely used in excitation control system to improve its control performance.In order to find the optimal PID controller parameters effectively ,a kind of Adaptive Particle Swarm Optimization method (CAPSO) based on Cloud Theory is applied to fuzzy PID controller. Through the establishment of particle swarm algorithm of fuzzy PID controller parameters optimization model, which it can be used to optimize the membership function of fuzzy PID controller. Particle code adopts real coding. Particle dimension is related with the number of the input variables divided by fuzzy set and the number of control rules of whole fuzzy control system, thus the parameters of PID control are optimized on real time. The result from the simulation shows that compared with PID control and fuzzy control this system has several advantages which are small overshoots ,fast response ,and good stable performance to improve the control performance of excitation control system.

There have been many reports on the design of active vibration control systems. Most of them have optimized control systems based on the LQ optimal regulator or H∞ control theory. However, there are no answers to the problem whether given passive parameters of plants (e. g., spring constant on damping coefficient) are 'suitable' for the designed controller. In this paper, we consider structure and control simultaneous optimization for an active vibration control system. To provide solutions, several methods have been proposed which are based on tuning the design paramethers existing in the structure and controller. Most of the control laws are those of standard LQ optimal requlators which require full states measurements and estimate performance of a closed-loop control systems in the time domain. From the viewpoint of active vibration control, it is natural to discuss the performance of the control system in the frequency domain. Therefore, we adopt the frequency shaped LQG control law in simultaneous optimization design, which enables output feedback control and frequency shaping.

Control of an Unstable Batch Chemical Reactor

This paper presents design and research studies in marine loading arm plant system. Artificial Neural Network (NN) and ELM (Extreme Learning Machine) methods are used and compared in this valve control system by implement it in a prototype using microcontroller. This prototype use value of temperature sensor and value of ammonia gas sensor in the furnace as parameter of heat to control the flow of air and valve of safety device. The temperature sensor used in this research is the type of DHT11. The ammonia gas sensor is MQ sensor. This prototype also uses fan and servo as the actuator. Fans are used to supply the oxygen and servo is used to control the valve of ammonia. From the experimental result, the data shows that the optimization of safety device system using ELM method works better compared with NN. The control system has a very good response and it can work well (percentage of error is less than 0.4%). Hence, if the system is applied in the marine loading arm plant, it could improve the performance of safety device control systems and save the leakage of ammonia gas.