Complex Control Systems Research Articles

Numerical and experimental studies of the electrical communication sensing device for the tunnel boring complex control system

The article considers the issues of studying the magnetic field distribution created by the power electric cable in the loca-tion of the tunneling shield of the tunnel boring complex by numerical modeling with the subsequent full-scale experi-ment on the device layout. The influence of external magnetic field sources on the readings of three-component ferro-probe sensors was determined. The significant influence of parasitic noise caused by external magnetic fields and high sensitivity of sensors has been determined, which requires the use of additional filters. When using ferroprobe sensors, the most informative is the sensor component coinciding with the longitudinal axis of the tunneling shield. Studies have shown that at current values more than 200 A and change of cable location during the experiment, there is a possibility to register signals on other components of the ferroprobe sensor and subsequent location determination of the cable with current. The results of the experiments confirmed the possibility to practically realize the multisensor device of the control system of the tunnel boring complex shield movement process.

An Optimization Method of Flexible Manufacturing System Reliability Allocation Based on Two Dimension-Reduction Strategies

As increasingly extensive applications of flexible manufacturing systems (FMSs) arise, their reliability allocation has been a research hot spot. But, since FMSs are always composed of transfer and buffer devices, production machines, and complex control systems, the large number of basic elements makes the number of variables and constraints of reliability-allocation optimization increase greatly, which leads to the difficulty and inefficiency of optimization. To solve the above problem, two dimension-reduction strategies are proposed for the FMS reliability optimization with low cost and a high level of reliability as the objectives, and they are the reliability-weight double-threshold qualification strategy (RWTS) and the bi-level optimization strategy (BLOS), respectively. Based on these two strategies, an overall reliability-allocation optimization model and a bi-level reliability-allocation optimization model are established based on the FMS reliability evaluation presented in our previous work, and their algorithms based on particle swarm optimization (PSO) are presented. In terms of their contributions, for the RWTS, thresholds of reliability and the weight index of each basic element are set to dynamically reduce the number of variables in each iteration of the optimization; for the BLOS, the overall reliability-allocation optimization problem for transitioning from the FMS to basic elements can be transformed into simpler allocation optimizations from the FMS to subsystems and from subsystems to basic elements, which have fewer variables, and this can largely improve the optimization convergence performance. Through applying this to a box-parts finishing FMS, compared with the traditional optimization method, the high efficiency and the good allocation effect of the optimization based on these two strategies for improving convergence speed are verified by the simulation results. The proposed method has great significance for FMS design due to its limited cost but high-reliability requirement.

Caputo-Fabrizio type fractional differential equations with non-instantaneous impulses: Existence and stability results

In the current article, we establish the existence and uniqueness of solutions to the initial value problem for nonlinear implicit fractional differential equations with non-instantaneous impulses, including the Caputo-Fabrizio fractional derivative. This derivative encapsulates non-local and memory-dependent effects in the system's behavior. The problem's complexity arises from its implicit nature, where the relationships between variables are not directly specified. This inherent intricacy is further compounded by the introduction of non-instantaneous impulses, signifying abrupt, intermittent changes within the system at specific junctures, which in turn trigger sudden transitions. At its core, the initial value problem is concerned with deciphering a system's behavior based on its initial conditions, necessitating a solution that adheres to the given equation while considering the presence of non-instantaneous impulses. To derive the existence results, the study leverages established mathematical tools, specifically, the standard Banach's fixed point theorem and Darbo's fixed point theorem connected to Kuratowski's measure of noncompactness (KMN). Furthermore, the Hyers-Ulam stability (HU-stability) of the given problem is discussed, which, in turn, enhances the utility and reliability of these solutions in practical applications. In order to demonstrate the applicability of the discovered results for various values of δ, we construct some examples towards the end. The practical implications of these results extend to a wide range of fields, offering improved modeling, control, and understanding of complex systems.

Fuzzy Controller from Experts’ Rules for Middle Axis Ball and Beam

The present study examined the nonlinear system of Ball and Beam, to design an intelligent controller for this dynamic system. The authors formulated a mathematical model for the system and performed simulation testing using MATLAB to control it. It is noteworthy that the mathematical model was exclusively used for simulation purposes and not for building the controller. The author's team then proceeded to develop a Fuzzy Controller for the simulation model of the Ball and Beam system. Subsequently, the team tested the Fuzzy controller on the actual Ball and Beam model. The primary objective of this study was to assess the feasibility of building and controlling an intelligent controller for a nonlinear object, without relying on its mathematical model. The findings of the study can be useful in designing and controlling complex systems that are difficult to model mathematically.

Defocus Controller for a Rotatory Fresnel Collector

Solar heat for industrial processes (SHIP) is becoming one of the most attractive solutions for industry decarbonisation. Solar plants require a complex control system to manage the fluctuation of their source, solar radiation. One of the problems of this system is the possibility of overheating when solar production is greater than consumption. The main objective of this study was to design a defocus controller for the SunDial, the rotatory Fresnel collector. A dynamic simulation was carried out for a SHIP system with the defocus controller. Finally, a solution to satisfy the accuracy needed for the SunDial was presented.

The Role of PLC in Automation, Industry and Education Purpose: A Review

Programmable logic controller (PLC) plays a significant role in every era, either it is in field of automation, industry or educational purposes. As the demand for automation grows exponentially, control systems need to be easy to program, flexible, reliable, and cost-effective. This article provides an overview of PLC implementation in automation, industry, and education. This article reviews an investigation into the role of PLC in automation, industrial, and educational goals. PLC has its own limitations, but research shows that it has more benefits than limitations. After survey it will see that the PLC can be used in any application, either it is simple or complex control systems. The analysis conducted and focuses on the concept, operation, advantages and practical applications of PLC, as well as comparison with other control systems.

Improving safety management in railway stations through a simulation-based digital twin approach

In the dynamic milieu of modern, bustling railway stations, the emphasis on safety and efficient pedestrian traffic management has never been more crucial, elevating the significance of Digital Twins (DTs). DTs bring transformative changes in the way we approach the design, operation, control, and maintenance of complex systems, such as transportation hubs. However, documented real-world applications are lacking, leaving scientists and practitioners without valuable insights on DT implementation. Drawing from a case study centered around a prominent Italian railway station, this paper showcases the prototype of a simulation-based DT that empowers station managers with capabilities such as pedestrian flow prediction, early congestion warnings, evacuation response planning, layout optimization, and intelligent gate management. The simulation-based DT acts as a sophisticated mirror reflecting the dynamics of a station's crowd, drawing data from its physical counterpart with a certain frequency, simulating the evolution of the system over a given time horizon, returning warning messages to the decision maker if issues are identified, and evaluating ex-ante different corrective solutions. The latter becomes crucial for controlling the physical world, providing a closed-loop system. Our case-based framework validates the effectiveness of methods and technical solutions engineered ad-hoc to achieve an acceptable tradeoff among accuracy, performance, and scalability. This includes addressing challenges related to the synchronization of the virtual and physical world, data integration and interoperability with existing systems, and human-system interaction. Ultimately, this contribution serves as a valuable resource, bridging the gap between theoretical concepts and tangible applications in the realm of transportation hub management.

Regularization of the Solution of a Nonlinear Integral Equation of the First Kind

Integral equations, the main branch of mathematics, are widely used in physics, engineering, mechanics, control theory and other fields. Related to the application of integral equations, new fields are developing, such as economics, some sections of biology, etc. The theory of integral equations mainly developed in the late nineteenth-early twentieth century, starting with Vito Volterra (1982, 1986), Eric Ivar Fredholm (2010), David Hilbert, Erhard Schmidt, etc. scientists began to study it. Nevertheless, within the framework of mathematical concepts that existed before the first half of the twentieth century, such problems were considered incorrect because a small change in the given functions led to a greater change in the desired functions. The Volterra equation of the first kind is an integral equation that has an exact solution only in some cases. The limit of integration has been carried out in very small quantities on non-classical linear and nonlinear integral equations with variable limits and the construction of solutions in these works is based on numerical methods. Therefore, for the so-called non-classical Volterra integral equations, it is relevant to determine the conditions that ensure the uniqueness and regularization of their solutions. In this paper, the uniqueness of the solution of the non-classical nonlinear integral Volterra equation of the first kind is resolved. The aim of the study is to solve the non-classical Volterra integral equation of the first kind, that is, to determine the conditions that ensure the uniqueness of the solution of the nonlinear non-classical Volterra integral equation of the first kind. The proposed methods can be used for the study of integral, integral-differential equations such as the Volterra integral equation of the first kind, as well as for the qualitative study of some applied processes in physics, ecology, medicine, geophysics, and the theory of control of complex systems.

Soft-stable interface in grasping multiple objects by wiring-tension

Efficiently manipulating objects in a group state poses an emerging challenge for soft robot hands. Overcoming this problem necessitates the development of hands with highly stable structures to bear heavy loads and highly compliant designs to universally adapt to various object geometries. This study introduces a novel platform for the development of robot hands aimed at manipulating multiple objects in each trial. In this setup, the objects come into soft contact with an elastic wire affixed to the finger skeletons. This combination results in a harmonious hybrid finger, inheriting both the soft, flexible properties of the wire and the robust stability provided by the finger skeleton. To facilitate this approach, a theoretical model was proposed to estimate the kinematics of manipulating multiple objects using wiring-based fingers. Based on this model, we designed a hybrid gripper comprising two wiring-based fingers for conducting experimental evaluations in manipulating four groups of samples: a pair of bevel gears, a pair of bevel gears plus a pneumatic connector, a pair of glue bottles, and a pair of silicon bottles. The experimental results demonstrated that our proposed gripper reached good performance with high success rates in durability tests conducted at various lifting velocities and high adaption with objects in soft-friendly ways. These findings hold promise for efficiently manipulating multiple complex objects in each trial without the need for complex control systems.

Modular Open-Source Design of Pyrolysis Reactor Monitoring and Control Electronics

Industrial pilot projects often rely on proprietary and expensive electronic hardware to control and monitor experiments. This raises costs and retards innovation. Open-source hardware tools exist for implementing these processes individually; however, they are not easily integrated with other designs. The Broadly Reconfigurable and Expandable Automation Device (BREAD) is a framework that provides many open-source devices which can be connected to create more complex data acquisition and control systems. This article explores the feasibility of using BREAD plug-and-play open hardware to quickly design and test monitoring and control electronics for an industrial materials processing prototype pyrolysis reactor. Generally, pilot-scale pyrolysis plants are expensive custom designed systems. The plug-and-play prototype approach was first tested by connecting it to the pyrolysis reactor and ensuring that it can measure temperature and actuate heaters and a stirring motor. Next, a single circuit board system was created and tested using the designs from the BREAD prototype to reduce the number of microcontrollers required. Both open-source control systems were capable of reliably running the pyrolysis reactor continuously, achieving equivalent performance to a state-of-the-art commercial controller with a ten-fold reduction in the overall cost of control. Open-source, plug-and-play hardware provides a reliable avenue for researchers to quickly develop data acquisition and control electronics for industrial-scale experiments.

Ontological aspects of the problem of realizability of control of complex systems

The article deals with the management of complex systems. The general definitions of the concepts "control" and "control system" are formulated. It is stated that the control system in its basis is an information system, for which the most important characteristics are performance and rapidity. Definitions are given and differences between these characteristics are revealed. The problem of realizability of control of complex systems is stated, which consists in the necessity of providing sufficient rapidity, at which the whole necessary complex of control operations is placed in the control cycle. The relationship between the control parameters: the complexity of the control object, the duration of the control cycle and the rapidity of the control system is investigated. As a result, a number of significant dependencies are revealed: the duration of the control cycle is approximately inversely proportional to the complexity of the control object; the rapidity of the control system is approximately proportional to the square of the object complexity. It is stated that within the framework of the general theory of systems there are two main options for increasing the stability of a complex system: the option of monocentrism with a central element, or by increasing the number of links in the object. The first option does not allow increasing rapidity. The second variant of stability can be implemented in practice in the form of a decentralized system. The latter option is universally realized in living systems and is promising for the control of technical systems.

Quantitative Robustness for Signal Temporal Logic With Time-Freeze Quantifiers

Signal Temporal Logic (STL) is a variant of Metric Temporal Logic (MTL) which can express intricate temporal requirements over signals, and has found wide adoption for expressing requirements over complex control systems models. A key factor in the success of STL has been that of quantitative robustness, and the development of efficient algorithms for computing the robustness values over traces. The real-valued quantitative robustness of a signal with respect to an STL property quantifies the degree of satisfaction or violation of the property by the signal. In this work we introduce a notion of robustness for a more expressive logic, Timed Signal Temporal Logic (TSTL), which can be seen as Timed Propositional Temporal Logic (TPTL) with predicates defined over real-valued signals. This logic can express many natural engineering requirements that STL cannot. We also develop algorithms for computing this robustness value over traces in the pointwise semantics. While the robustness computation for general TSTL formulae is PSPACEhard due to the PSPACE-hardness of the monitoring problem for TPTL, for the special case of one variable TSTL, a fragment of TSTL which is still more expressive than STL, we develop an optimized algorithm which computes robustness in time linear in the length of the trace. Finally, we experimentally validate the tractability of our algorithms with our prototype tool in Matlab.

Scale optimization design and work behavior analysis of a single leg walking mechanism of quadruped robot

A general methodology for modeling and analysis of a single leg walking mechanism of quadruped robot is presented in this paper to solve the problems of more drive elements, more complex structure and control system in existing single-leg walking mechanism. The principle scheme and scale optimization design of proposed walking mechanism are completed according to the requirements of the foot end trajectory curve and Grashof’s criterion. The models of kinematics and dynamics of presented mechanism have been built. By numerical calculation, the variations of displacement, the angular velocity and moment of the equivalent crank are discussed. The results indicate that the kinematic and dynamic properties of the optimized mechanism are better than those before optimization. Furthermore, these results provide a basis for the structural design of a single leg walking mechanism of quadruped robot.

Short-Term Prediction for Indoor Temperature Control Using Artificial Neural Network

Recently, data-based artificial intelligence technology has been developing dramatically, and we are considering how to model, predict, and control complex systems. Energy system modeling and control have been developed in conjunction with building technology. This study investigates the use of an artificial neural network (ANN) for predicting indoor air temperature in a test room with windows on an entire side. Multilayer perceptron (MLP) models were constructed and trained using time series data obtained at one-second intervals. Several subsampling time steps of 1 s, 60 s, 300 s, 600 s, 900 s, 1800 s, and 3600 s were performed by considering the actual operation control mode in which the time interval is important. The performance indices of the neural networks were evaluated using various error metrics. Successful results were obtained and analyzed based on them. It was found that as the multi-step time interval increases, performance degrades. For system control designs, a shorter prediction horizon is suggested due to the increase in computational time, for instance, the limited computing capacity in a microcontroller. The MLP structure proved useful for short-term prediction of indoor air temperature, particularly when control horizons are set below 100. Furthermore, highly reliable results were obtained at multi-step time intervals of 300 s or less. For the multivariate model, both calculation time and data dispersion increased, resulting in worsened performance compared to the univariate model.

Deployment of Model-Based-Design-Adaptive Controllers for Monitoring and Control Mechatronic Devices

The modeling and control of complex, non-linear, and time-changing mechatronic systems requires complex software development. They are carried out in the prototyping phase with engineering software development tools, generating models, and control algorithms that are not always easily exportable to control hardware. The following work offers an alternative that considers Model-Based Design using graphics-based languages, which facilitates programming tasks for modeling and controlling mechatronic devices and their transition from prototype to control hardware. Model-Based Design with high abstraction programming level capabilities provides the user with a fast coding and testing environment, suitable for laboratory prototyping and subsequent transfer to commercial embedded controllers. The proposed solution combines control hardware based on an STM32H7 microcontroller and a software development environment using graphics-based languages developed for MATLAB. The result is a solution that integrates control hardware and software in a hardware-in-the-loop paradigm. This solution provides robust and energy-saving controllers and demonstrates that an advanced control algorithm can be set up in a critical safety-compliant low-cost embedded controller via a custom model-based design. Algorithms and tools are transferred to the controller without losing the advantages gained in the prototyping phase. Finally, experimental results implementing an adaptive controller in a DC motor and in a pneumatic system are shown to validate the system.

An Investigation of Stability, Controllability and Observability of a Three Degree of Freedom Translational Mechanical System using State Space Approach

State-space modelling approach which is essentially time-domain developed in the late 1960s is a new approach to the analysis and design of complex control systems. Several researches have carried out modelling and analysis of mechanical systems with a number of degrees of freedom of movement using state space approach among which is the work of Sivak and Darina (2012) who modelled a system with two degrees of freedom. In this paper, therefore, we provide an extension of the work of Sivak and Darina to model and analyse a three degree of freedom translational mechanical system using state-space approach. The system was first presented in equivalent free body diagrams, then Newton's second law of motion was used to derive its equations of motion. The State-space formulation in the controllable canonical form obtained from the time-domain differential equations is adopted and the Laplace transform method was used in the analysis to determine the poles (natural frequencies) of the system using two numerical examples in MATLAB software. The software was also used to determine the controllability and observability matrices of the system. The stability, controllability and observability of the system were then discussed from the poles, controllability matrix and observability matrix respectively. Tables of numerical values and line graphs were used to present the results obtained from the analysis. Finally, in these results, the system was found to be stable, controllable and observable suggesting that a state feedback ( pole placement ) control design for the system is possible.

Using a quadratic quality criterion for the synthesis of complex control systems

The main difficulties, which are blamed for the synthesis of system control of wheeled machines according to the quadratic criterion of efficiency, are the choice of elementary matrices, with which the system of dynamic characteristics is synthesized. Therefore, in the robot, the information about the establishment of the fallowness of the dynamic powers of the optimal system in terms of the value of the elements of the matrix of the matrix according to the criterion of capacity is considered. Since the number of elements is the most important parameters for the synthesis, it is hoped that it will be possible to recognize the most important coefficients, without intermediary swaying through the parameters of the transitional process in the system.

Predicting saddle-node bifurcations using transient dynamics: a model-free approach

This paper proposes a novel method for predicting the presence of saddle-node bifurcations in dynamical systems. The method exploits the effect that saddle-node bifurcations have on transient dynamics in the surrounding phase space and parameter space, and does not require any information about the steady-state solutions associated with the bifurcation. Specifically, trajectories of a system obtained for parameters close to the saddle-node bifurcation present local minima of the logarithmic decrement trend in the vicinity of the bifurcation. By tracking the logarithmic decrement for these trajectories, the saddle-node bifurcation can be accurately predicted. The method does not strictly require any mathematical model of the system, but only a few time series, making it directly implementable for gray- and black-box models and experimental apparatus. The proposed algorithm is tested on various systems of different natures, including a single-degree-of-freedom system with nonlinear damping, the mass-on-moving-belt, a time-delayed inverted pendulum, and a pitch-and-plunge wing profile. Benefits, limitations, and future perspectives of the method are also discussed. The proposed method has potential applications in various fields, such as engineering, physics, and biology, where the identification of saddle-node bifurcations is crucial for understanding and controlling complex systems.

Asymmetric Mach-Zehnder prism interferometer coupler-based combined fiber ring resonator system for a Brillouin gyroscope.

Brillouin fiber-optic gyroscope (BFOG) is a fiber ring resonator (FRR)-based ring laser gyroscope with a large dynamic range and high sensitivity. Previous BFOGs operated under simultaneous resonance of the pump and Brillouin laser light in the FRR, resulting in complex control systems. This article introduces an asymmetric prism Mach-Zehnder interferometer coupler (APMZIC)-based FRR system, in which the coupling ratio of pump light is large, while the Brillouin laser resonates in the cavity with a negligible coupling loss, resulting in a simple control system. We analyzed the characteristics of the APMZIC and its combined resonator system both theoretically and experimentally and verified the feasibility of connecting the APMZIC with the resonant cavity of a Brillouin laser. This coupler system is compact, easy to fabricate, highly stable, and exhibits good repeatability, which are necessary for miniaturizing lasers and gyroscopes.

Энергетический комплекс на базе высокооборотной электрической машины

Purpose: The purpose of this study is to develop the scientific basis for designing high-speed electric generators used in conjunction with gas micro-turbines. Methods: To solve the tasks set, the theories of electrical machines; the finite element method; automatic control theory; methods of mathematical analysis, mathematical and circuit modeling; numerical modeling on a PC using FEMM and Matlab Simulink software complexes have been used. The research has been carried out on experimental samples of a high-speed electric generator and confirmed by the results of tests as part of an energy complex based on a gas microturbine in 2019. Results: A complex of scientifically based technical solutions for the design of a high-speed electric generator with an energy complex control system based on a micro-gas turbine has been developed. As a result, a high-speed electric generator for a gas microturbine with a power of 100 kW and a rotation speed of 100,000 rpm has been developed and manufactured. When designing, an asynchronous type electric generator with a massive rotor has been selected. A feature of the developed design is the use of a five-phase stator winding. A control system of an experimental sample of a high-speed electric generator for micro-GTU has been developed. Practical significance: It lies in the development of methods and algorithms for designing high-speed generator equipment for micro-GTU. Recommendations have been developed for choosing the type and configuration of a high-speed electric generator for an electric complex based on a micro-gas turbine. A method is proposed for calculating the parameters of the substitution circuit of a highspeed electric generator, which allows us to determine the parameters of the substitution circuit according to the known configuration of the active layer at the design stage.