Design Of Digital Control System Research Articles

Design of Digital Control System for Line Following Robot

Design of mobile robots has become an increasingly growing trend in the technology of modern times. They are very attractive engineering systems, not only because of many interesting theoretical aspects concerning kinematics, intelligent behavior and autonomy, but also because of applicability in many human activities. A typical example is the line following robot (LFR). In order for a LFR to function effectively, it must demonstrate excellent line tracking control. This is achieved by having accurate and responsive control algorithms as well as high precision color sensor systems. This paper proposes a system to show that good line tracking performance can be achieved with moderately simple digital control algorithms. The platform used is a differentially driven wheeled robot constructed using the Lego Mindstorms components. The simulation models are presented and analyzed using MATLAB Simulink . The main programming environment is the EV3 Software.

Design of Discrete and Hybrid Nonlinear Control Systems

In this article the new method of discrete control systems design for nonlinear plants with differentiable nonlinearities is suggested. The increasing demands on the quality of control processes and the widespread use of computer technology provide ample opportunities for the design and implementation of digital control systems. However, discrete models of control plants are needed to solve this problem. In the case of linear plants, such models are created on the basis of z-transformation, Euler or Tustin formulas. In the case of nonlinear plants, these transformations are not applicable, so a large number of approximate discretization methods have been developed to date. Euler and Runge-Kutt transformations are used for these purposes most often, but they lead to satisfactory results only with very small period of discretization. In the case of automatic control systems, this requires the use of digital automation tools with very high speed, which is often economically impractical. Methods of discretization with a long period were most often developed on the basis of decomposition into series of the right-hand sides of the differential equations, transformed on Euler. Here, firstly, the problem of selecting the number of the series members, which to be retained arises, and secondly, already in the third or fourth order of the plant, the calculating ratios turn out to be extremely complex. The discretization method suggested below differs in that it is not the equations of nonlinear plants in the Cauchy form that are discretized, but the corresponding quasilinear model. In this case, a modified trapezoid method is used, and the discretization purpose is not the most accurate approximation of the original equations of the plant, but the stability of a closed nonlinear control system with rather big period. This system is designed using the algebraic polynomial-matrix method for designing of the nonlinear control systems. As a result, a hybrid nonlinear system with fairly simple algebraic calculation expressions is formed. The suggested approach makes it possible to create the control systems for nonlinear controlled plants using conventional computational automation tools.

Research on the influences of information presentation on information capture and performance in digital control systems

ABSTRACT This study investigates the effects of information presentation on operator performance in digital control systems at different levels of task difficulty in order to resolve the conflict between ‘large amounts of information’ and ‘limited display’. By using software to present figures of varying difficulty as target information, the operator’s behaviour such as page switching and target clicking is simulated to obtain data. Simultaneously, eye-tracking technique was used to analyse how the way information was presented at different levels of difficulty influenced the subjects’ search performance. The results show that subjects’ performance gradually decreases as the difficulty of the numbers grows for both presentations, and it is found that the complexity of the content of the navigation bar may have influenced the subjects to some extent. In addition, the different position of the navigation bar where the target is located will result in a change in the search pattern. It is noticeable that dividing the single page into double pages can effectively alleviate the contradiction of ‘large amount of information’ and ‘limited display’ in designing the system interface. Therefore, this study provides certain guideline value for the interface design of digital control systems.

Experimental studies of using the digital control system in power conversion equipment of high-voltage power supply systems in spacecrafts with a hydrogen energy accumulator

Solar-hydrogen energy for spacecraft, space interplanetary stations, space bases on the planets of the solar system must reliably provide energy: spacecraft during peak periods (repairs at a space facility, energy-consuming experiments, cleaning of facilities, regeneration of waste to extract oxygen and hydrogen, etc. .d.) and bases on planets, especially where the night lasts for a long time.The onboard hydrogen module of the solar-hydrogen plant includes: a container with water; distiller; deionizer; water lines with adjustable shut-off valves; electrolyzer; cryogenic side tanks with hydrogen and oxygen; fuel cell, hydrogen safety sensor systems based on leakage and concentration sensors; level gauges; cryogenic and gas pipelines of hydrogen and oxygen; onboard cryo-refrigerator; automatic control system for the hydrogen module. The article presents the results of experimental studies of static, dynamic and mass-dimensional characteristics of power conversion equipment (hereinafter - PCE) in the power supply system (hereinafter - PSS) of the spacecraft (hereinafter - spacecraft) with a digital control system. The purpose of experimental research is to verify the theoretical results obtained earlier in the design of digital PCE control systems of high-voltage PSS spacecraft, including the study of static and dynamic characteristics. We developed and manufactured an experimental PCE sample with an output power of 2500W in this research. It includes: four voltage stabilization modules and the 100V load supply output bus filter. Each voltage stabilization module includes a battery energy conversion channel, a solar battery energy conversion channel and a digital control system unit. The power conversion channel of the accumulator battery is designed and made on the basis of a bridge volt-booster inverter-transformer circuit. Voltage control in energy converter of accumulator battery is based on phase shift in control pulses of transistors in adjustable inverter rack related to unregulated one. The power conversion channel of the solar battery is designed and made on the basis of a two-phase circuit of a direct voltage converter of an increasing type with switching throttles. The digital control system of the voltage stabilization module is designed on the basis of analogues in the modern electronic component base in the Space class and consists of four identical channels. Each channel of the control system controls its own voltage stabilization module. We obtained the following results during our experimental studies: some pulsations of the output voltage of the energy conversion equipment during operation on an active load, transient processes of the output voltage of the energy conversion equipment during pulsations of the load current without changing the mode of operation, transient processes of the output voltage of the energy conversion equipment when changing the modes of its operation and weight and size characteristics for different values of the output power. The obtained results of experimental studies confirm the previously obtained theoretical results, and also showed that the use of a distributed digital control system will increase the specific energy characteristics of the newly developed PSS spacecraft while ensuring the given static and dynamic characteristics of output voltage quality. The results of the work are designed to create a new on-board power conversion equipment for power supply systems of promising spacecraft. The area of application of the project results is space instrumentation.

Expanding the Remote Experiment Set with the 3Axis Portal Physical Model

The problem of insufficient variety of experiments with physical models in laboratory workshops for distance learning in the design of control systems is posed. It is caused by the limited operations with the physical model when using the interface at the level of electromechanics control. The way of solving the problem is substantiated: the transition from electromechanics control of physical models of devices to control systems for the processes of using these devices. The proposed way to increase the number of types of experiments is illustrated with examples of systems for using popular physical models of an elevator, storage warehouse and production cell. However, the main focus is on expanding the functionality of the physical model 3-Axis Portal. These possibilities are realized by equipping the portal head of the base model with new sensors and actuators, improving the loads with which the portal works and using new types of active surfaces in the working field of the portal. Based on the aggregation of the proposed nodes with the basic portal model, sixteen types of systems for setting up remote experiments are described. The structures of these systems, elements of implementation and variants of experiments are described, which relate to the design of digital control systems, visualization of sorting algorithms, technical diagnostics of electronic assemblies, pattern recognition and other relevant topics for teaching students of engineering specialties.

Design of digital nuclear power small reactor once-through steam generator control system

The once-through steam generator used in the small modular reactor needs to consider the stability of the outlet steam pressure and steam superheat of the secondary circuit to achieve better operating efficiency. For this reason, this paper designs a controllable operation scheme for the steam pressure and superheat of the small reactor once-through steam generator. On this basis, designs a variable universe fuzzy controller, first, design the fuzzy control rules to make the controller adjust the PI controller parameters according to the change of the error; secondly, use the domain adjustment factor to further subdivide the input and output domain of the fuzzy controller according to the change of the error, to improve the system control performance. The simulation results show that the operation scheme proposed in this paper have better system performance than the original scheme of the small reactor system, and controller proposed in this paper have better control performance than traditional PI controller and fuzzy PI controller, what's more, the designed control system also showed better anti-disturbance performance in lifting experiment between 100% and 80% working conditions. Finally, the experimental platform formed by connecting the digital small reactor with Matlab/Simulink through OPC(OLE for Process Control) communication technology also verified the feasibility of the proposed scheme.

Influence of Programmable Logic Controller Program Structure to Digital Inputs Reaction Time

Design of digital control systems is often based on use of Programmable Logic Controllers (PLC). Such devices offer a broad variety of functions that can be organized in blocks independently or in hierarchical structures. Such an organization can lead to cumulative delays in reaction time of digital outputs of the control system. In the paper there are described results of research aimed to determine dependencies of various aspects of designing programs for Programmable Logic Control devices influencing the effective time of reaction of digital outputs. Research method is presented, assumptions are made, and experiments are described and discussed. Observations of system behavior are presented for selected control tasks and different control situations. Research results are presented and discussed, conclusion is drawn, and areas of future work are identified.

Control-oriented regularization for linear system identification

In this paper, we develop a novel theoretical framework for control-oriented identification, based on a Bayesian perspective on modeling. Specifically, we show that closed-loop specifications can be incorporated within the identification procedure as a prior of the model probability distribution via suitable regularization. The corresponding kernel varies according to the additional penalty term and provides a new insight on control-oriented identification. As a secondary contribution, we derive a Bayesian robust control design approach exploiting all the information coming from the above modeling procedure, including the estimate of the uncertainty set The effectiveness of the proposed strategy against state-of-the-art regularized identification is illustrated on a benchmark example for digital control system design.

Design of Digital Control Systems by Nonlinear Uncertain Objects

Minimum-phase nonlinear objects in the conditions of incomplete information about state variables and nonlinearities of the objects are considered. The design method of the digital automatic control systems in the conditions of uncertainty is offered. The decision is received with application of the asymptotic observers and control on state and impact under conditions of full controllability and observability of the controlled objects. This control provides the necessary performance of the control systems. The digital devices algorithm of digital control system is received by sampling of the found control. The efficiency of the developed method is shown on the numerical example. The developed method can be applied to design of digital control systems of production and technological objects of various assignment.

Designing of Digital Control Systems by Dynamic Objects with Uncertain Nonlinearity

This article is devoted to development of a method of the digital control systems design with not gaged state variables of the object with uncertain nonlinearity. Application of two observers to find the asymptotic es-timates of the nonlinearity and the state vector of the object is the main feature of the developed approach. The problem of designing is solved on the basis of the discrete-time model of the object with application of the con-trol on output and impacts and the standard normalized transfer functions. It allows to provide the required indicators of quality both in established, and in a transient mode. The numerical example illustrates effectiveness of the developed method. The obtained results can be used to design of digital control systems which can significantly increase effectiveness of the controlled objects as production and special assignment.

Design of Digital Control System for High-performance Ionosonde Based on FPGA

为建立天地一体化电磁观测系统，实现电离层等的实时准确观测，为地震机理的研究与地震预报工作提供科学有效的数据，提出了一种高性能电离层测高仪数控系统设计方案将应用于电磁卫星的地面同步验证系统中，给出了数控系统的时序控制单元、发射单元和接收单元等的具体实现.在收发延迟可变的雷达时序控制下，发射单元利用直接数字合成技术产生1～30MHz的脉冲信号，40位类巴克码对脉冲信号进行二进制相位调制编码，随后交替发射正交极化波；接收单元利用高速模数转换器实现信号的数字化，采用FPGA技术进行下变频处理.本数控系统的设计可直接获取回波信号的极化信息，高度分辨率为1.5km，探测周期小于2min.实验结果表明，该数控系统方案切实可行.

Обеспечение устойчивости работы энергетических объектов на основе защиты цифровых систем управления

Introduction. The expansion of the range of threats of critical information impacts (attacks), all of which are difficult to foresee in the design and development of digital control systems, has actualized the development of new approaches, the use of which makes it possible to detect attacks, identify them and develop control commands to stabilize equipment operation, increase the resilience of energy facilities to critical information impacts (attacks). The purpose of the study is to solve the problem of protection against unauthorized interference in the operation of automatic and automated systems that control functional units of power equipment to achieve reliability and safety of power supply as an element of ensuring technosphere safety. Research methods. Within the framework of the study, general scientific and special methods of scientific knowledge were used, including analysis, synthesis, generalization, which were based on the main provisions and patterns of behavior of systems and information theory. Research results. It is proposed to create a system for monitoring the stability of energy facilities to critical information impacts (attacks), adapted to work in emergency situations and in a special period. The characteristics of the system, the main functions, components, key modules (subsystems), the main stages of development, implementation and ensuring the efficiency of work are formulated. Conclusion. The advantage of the system is its adaptation to abnormal behavior (including for unknown reasons) of functional units of equipment in order to achieve reliability and safety of power supply as an element of ensuring technospheric safety. The system allows you to reduce the workload and responsibility of operators, especially in situations where there is no, lack of reliable information or the presence of questionable technological information. Keywords: energy, digital control systems, threats, protection, security, intelligent elements, equipment

Design and Application of a Dual Processor Digital Control System for Ultra-High Frequency Pulsed Gas Tungsten Arc Welding

Design and Application of a Dual Processor Digital Control System for Ultra-High Frequency Pulsed Gas Tungsten Arc Welding

Digital Identification and Control of Multivariable Plants Using Markov Parameters

Abstract The algorithm of the digital adaptive controller is offered in this article for control systems with identification of uncertain multivariable continuous-time objects. The adaptive controller includes unit of digital identification and unit of digital control. The algorithm of the identification unit allows to define the transfer matrix of the uncertain continuous-time plant. Unlike traditional methods of identification, the offered analytical algorithm uses Markov parameters not of the uncertain continuous-time plant, but virtual discrete-like plant. Markov parameters are determined by data of I/O of the uncertain continuous-time plant. The algorithm of the control unit is developed with use of control of two types: decomposition control and digital control on the output and impacts. The order and parameters of the control unit are determined by the method of the analytical design of digital control systems. Normalized standard transfer functions are used to create the transfer functions of the adaptive system according to required values of astatism order, settling time and overshot. The effectiveness of the proposed algorithm of adaptive controller is illustrated by a numerical example. The proposed approach can be applied to create control systems for agricultural, food, mining, and other industries.

Mathematical model of a digital control system with background controllers of the Neuman type for complex multicirculated objects

In the work, a mathematical model of digital control of multi-circuit objects is built, taking into account the real characteristics of a digital controller as an element of a control system. The problem is formulated that the methods of modeling digital control systems are known and are widely used in engineering practice, however, in the overwhelming majority, they involve the formation of models that do not take into account the presence of time intervals between transactions in a Von Neumann type computer. To solve the problem, a typical block diagram of complex multi-loop control systems with digital controllers of the Von Neumann type has been developed, which takes into account the random nature of the processed data and real time delays between transactions. It is proposed, taking into account the randomness of the time interval between transactions and the stochastic nature of switching to conjugate operators, to consider a semi-Markov process as an adequate model of the algorithm for the functioning of digital control systems. On the basis of semi-Markov processes, a method is proposed for estimating the parameters of time intervals between transactions in cyclic control algorithms, which makes it possible to evaluate the characteristics of the system at the design stage, and therefore is the key to the rational design of digital control systems for multi-circuit objects with control algorithms of almost any complexity. An example of mathematical modeling of a two-circuit system with digital control is presented.

Design of Digital Control System for DC/DC Converter of On-Board Charger

Vehicle charging power supply is widely used because of its small size and portability. Aiming at the problems of slow dynamic response, subharmonic, oscillation and limited soft-switching range of phase-shifted full-bridge DC/DC converter, the paper proposed a modified PSFB converter by introducing clamp diodes at the primary side of the transformer to suppress voltage oscillation of the transformer’s secondary side. Also, digital peak current phase-shifting control and slope compensation are introduced to avoid subharmonic oscillation. Dynamic dead-time control technology introduced adjust the dead-time in different load ranges through the dead-time adjustment subroutine. Finally, an experimental platform of on-board charging phase-shifted full-bridge DC/DC converter is established. The experimental results show that the power supply eliminates subharmonic oscillation, achieves a wide range of soft-switching, improves the dynamic performance and antiinterference ability of the system, and optimizes the power efficiency.

Design and Implementation of Digital Control System Based on PAC Architecture for Large-Capacity Pulse Power Supply

In Tokamak device, many larger capacity pulsed power supplies have been installed to provide high-energy magnetic field to control plasma. In this article, a new digital control system for satisfying larger capacity pulse power supply is introduced. This control scheme uses programmable automation controller (PAC) architecture, which consists of software platform and hardware platform to design a new digital control system, and in this system, real-time operation system (OS) and real-time communication network can provide much more precise and predictable timing characteristics to fulfill the requirements of the real-time control for pulse power supply in Tokamak device. Its hardware architecture based on integration and modularization can provide reliability, stability, and flexibility for digital control application; meanwhile, its software platform is used to handle data communication, close-looping control, protection strategy execution, and trigger output. After the digital control system of the large-capacity pulse power supply is built, its performance is verified through the HL-2A experiments. The result shows that the digital control system achieves the design goals and has high reliability and stability.

Design of Digital PID Control Systems Based on Sensitivity Analysis and Genetic Algorithms

Digital PID controllers design method in a parameter space is proposed in this article. Sensitivity analysis is processed to meet specifications in gain margin and phase margin. The stability boundary is plotted based on the proposed method in this article. The genetic algorithm is used for integral absolute error, integral time-weighted absolute error, integral square error, and integral time-weighted square error. A design procedure is proposed in this article. The design procedure is applied for a model of a boiler and a model with time delay. Computer simulation results show that the proposed method is effective.

Методи автоматизованого комп'ютерного проектування цифрового пристрою локального управління

The work is devoted to the issues of improving the reliability of logical control systems in supply systems. The presented method of computer-aided computer design of a digital device for local control (regulation). Based on a simplified algorithm for the functioning of the system, represented by GSA, an automaton model in the form of the transition graph of the Mile finite automaton consists. The transition graph is presented in the VHDL hardware description language in the form of a dual-process automaton pattern. According to the transition graph, an algorithm for diagnosing the control device is constructed according to the strategy of bypassing all the arcs of the graph, which guarantees its completeness. Based on the diagnostic algorithm, the VHDL model of the hardware diagnostic device is built. To diagnose the control finite state machine, it was proposed to conduct a “non-destructive” diagnostic experiment on traversing all vertices (arcs) of state diagram using synchronization sequences. The verification of the model of the diagnostics device developed is performed using the Active-HDL simulation system. Synthesis of control device and device diagnostics is performed using.To reduce the additional hardware costs for a device diagnosing in computer-aided design of digital control systems, methods of test-based design and built-in diagnostics should be used. The scientific novelty of the work consists in the further development of computer-aided computer-aided design of a digital local control device. The practical value of the results is in analyzing the circuit implementation (synthesis) of HDL models of the control device (control machine) and diagnostic hardware (diagnostic machine - the diagnostic device allows you to estimate the amount of additional equipment costs using Quine's criterion and analyzing the additional equipment costs and showed that they can be compared to the hardware costs of the control device itself, on the one hand, this increases the hardware costs of the digital system Thread management in general, but on the other hand, the implementation of management systems on an FPGA, SoC, as a rule, there is an untapped programmable logic, which can be used by diagnostic equipment.

Design of Digital Control System for Line Following Robot

Abstract Design of mobile robots has become an increasingly growing trend in the technology of modern times. They are very attractive engineering systems, not only because of many interesting theoretical aspects concerning kinematics, intelligent behavior and autonomy, but also because of applicability in many human activities. A typical example is the line following robot (LFR). In order for a LFR to function effectively, it must demonstrate excellent line tracking control. This is achieved by having accurate and responsive control algorithms as well as high precision color sensor systems. This paper proposes a system to show that good line tracking performance can be achieved with moderately simple digital control algorithms. The platform used is a differentially driven wheeled robot constructed using the Lego Mindstorms components. The simulation models are presented and analyzed using MATLAB Simulink. The main programming environment is the EV3 Software.