Design Method Of Control System Research Articles

Frequency Domain Design Method of the Aeroengine Fuel Servo Constant Pressure Difference Control System with High Performance

The constant pressure difference regulating mechanism is widely used in aeroengine fuel servo metering systems, and it almost decides the metering precision. However, the design theory and design method of the available constant pressure difference regulating mechanism are unclear, and it is difficult to follow the high stability, high accuracy, and high robustness requirements of the modern aeroengine fuel servo metering system. In this paper, the design theory of the constant pressure difference regulating mechanism is revealed, and it indicates that it consists of two basic control units: a state feedback stabilization controller to ensure the asymptotic stability and disturbance rejection performance; and a servo and feed-forward compensator to ensure the asymptotic tracking ability. In addition, based on the frequency domain analysis method, the decisive influences about the control gains of the two control units on the dynamic performance and stability are analyzed. On this basis, a frequency domain design method of the two core control gains is proposed to complete the design task of the closed-loop system. The simulation results show that, under the adverse conditions of 1 MPa strong step disturbance of the inlet pressure and 50 mm2 strong step disturbance of the variable inlet flow area, the steady-state working range of the controlled pressure difference meets 0.92 ± 0.01 MPa, the steady-state error is not more than 1%, the regulation time is not more than 0.01 s, the dynamic overshoot is not more than 10%, and the designed phase margin is more than 70°.

Design and Discussion on Information Management and Control System of Agricultural Machinery and Equipment

In order to solve the problem of low development efficiency of agricultural mechanization information network system, a design and discussion method of agricultural machinery equipment information management and control system is proposed. This paper introduces the technologies required to realize the agricultural machinery operation management control system: Android development technology required to develop mobile phone positioning software, Internet map API for displaying location data, and construction of agricultural machinery resource allocation model for the realization of the scheduling module. Different objective functions are set, and the model results in different situations are obtained through experimental data. The experimental data are in the case of schedulable agricultural machinery, if the target is short-distance short-distance operation, it can save time by 0.16 h, and the existing M1 model is in Changying. Village work, the work end time is about 2.5 hours; M4 and M2 models work in the Xuzhuang Village, and the work end time is about 0.5 h; M3 model works in the Jiangtang Village, and the calculation results for different goals are as follows: M1 model first dispatches short-distance operations; the M3 type is dispatched first for short-distance operations; the M4 type operating in Xuzhuang Village is given priority to dispatch short-distance and short-distance operations. According to the analysis of system requirements, each submodule of the system is designed, including the function description and realization method of the module. The history track query module, mobile phone positioning module, and agricultural machinery scheduling module are introduced in detail. Using the Android development technology required by mobile phone positioning software, the information management of user interface, server system, and database is realized, which provides conditions for the collection of agricultural machinery and equipment information and the generation of information management control.

Super‐spiral sliding mode controller design for single‐winding bearingless switched reluctance motor

The strong coupling effect between the torque system and the suspension system of the single-winding bearingless switched reluctance motor (SWBSRM) would result in continuous interference to the system and bring difficulties to the design of the control system. Moreover, strong external disturbances will further reduce the stability of the control system. To improve the anti-disturbance ability and enhance the robustness of the control system of SWBSRM, a design method of the entire control system based on the second-order sliding mode (SOSM) controllers is proposed. The strongly coupled SWBSRM torque system and suspension system are linearised and decomposed through the feedback linearisation method to benefit the design of SOSM controllers. Then, combined with a super-spiral algorithm, the super-spiral sliding mode controllers in the outer loop for torque and suspension system are designed separately. The design of controllers considers the interference caused by the coupling effect and the influence of external disturbance. The range of gain, which can ensure the finite time convergence of the control system is determined through proof of stability. Simulation and experiment results show that the second-order sliding mode controllers have faster response speed and control precision when suppressing coupled interference and strong external disturbance.

A new control strategy of stopped-rotor aircraft based on manipulation model

PurposeThe purpose of this paper is to study the control strategy of transition mode of the stopped-rotor (SR) aircraft under the condition of redundant control and complex aerodynamic characteristics.Design/methodology/approachThis paper first proposes a transition strategy for the conversion between helicopter mode and fixed-wing mode. Then, aiming at the redundancy of the two control systems in the transition process, a control model is proposed, which greatly simplifies the control in conversion mode. Then, to facilitate the design of the control system, the Takagi-Sugeno model of the SR aircraft in transition mode is established. Finally, an explicit model tracking and tuning parameter stability augmentation control system is designed, so that the SR aircraft has a good stability during the transition process. Then, the outer loop control system of transition flight is designed.FindingsThe simulation results show that the control strategy proposed in this paper can realize the mode conversion well. It lays a solid foundation for the subsequent engineering flight test for the SR aircraft.Originality/valueThe work done in this paper provides ideas and methods for the flight control system design of SR aircraft in transition mode. The method of designing control model to solve the coordination of redundant control system is also applicable for other multimode aircraft, which provides a simple and convenient method for the multimode aircraft control.

Design of Robust Decentralized Control Systems for Distillation Columns

This paper is devoted to the development of a decentralized control system design method with improved robustness, applicable to distillation columns control problem. The aim is attained by solving the following tasks: selection of representative models of columns; development of an effective transfer function identification algorithm; development of a decentralized controller design algorithm, which takes into account the cross-links impact; verification of the developed method for the selected models of columns. The most important result is the developed design method, which includes two algorithms. The first algorithm can be used to identify simplified models of the effective transfer functions. The second algorithm makes it possible to design a decentralized control system based on the ratio between the diagonals of the original model and effective transfer functions. Modified PI controller is used. The achievement of the distillation column control system robustness to the synchronous technologically conditioned deviation of the model parameters by up to three hundred percent of the nominal value is the paper significant result. The digital implementation of the designed controllers is simple. The analysis of the literature shows that none of the previously proposed methods for designing decentralized automatic control systems solved such a problem. The efficiency of the developed algorithms is illustrated using the known models of dynamics of distillation columns. The analysis of limitations of the method as well as its significant differences to the Biggest Log Tuning and H∞ loop shaping methods is presented.

Data‐driven dual‐rate cascade control and application to pitch angle control of UAV

SummaryA data‐driven design method for a cascade control system is proposed. The cascade control system consists of inner and outer loops, where the control interval of the outer loop is an integer multiple of the inner loop; hence, the system is a dual‐rate system. In the proposed method, controllers in the inner and outer loops are designed based on one‐shot data. In such a dual‐rate cascade system, since the controllers are designed using different data‐rate signals, the lifting technique is applied to align the dual‐rate data. To show its effectiveness, the proposed method is compared with a conventional single‐rate cascade control method, and numerical simulations and experiments are presented to examine servo and regulation performance.

Design of spaceborne self-closed loop extensible temperature control system based on FPGA

Abstract The paper describes the design method and implementation of a self-closed loop extensible temperature control system for spaceborne based on FPGA. FPGA is used as the core of data processing System. Firstly using the high accuracy AD and analog switch for temperature data collection. The FPGA is to filter data by average calculation, voltage correction algorithm and PWM controlling temperature algorithm. Finally, after processing temperature control parameters, according to the corresponding channel relation it outputs temperature control parameters to the corresponding control output on NMOS. It can be uploaded temperature threshold parameters through SPI bus, and the corresponding relationship parameters between temperature control and temperature measurement can be modified, and it carry out the remote sensing function on the earth. The system can realize multi-system cascade temperature control through Rs422 bus. This process realizes a complete self-closed loop process, and finally achieves the system design goal.

Full mode flight dynamics modelling and control of stopped-rotor UAV

The Stopped-Rotor (SR) UAV combines the advantages of vertical take-off and landing of helicopter and high-speed cruise of fixed-wing aircraft. At the same time, it also has a unique aerodynamic layout, which leads to great differences in the control and aerodynamic characteristics of various flight modes, and brings great challenges to the flight dynamics modelling and control in full-mode flight. In this paper, the flight dynamics modelling and control method of SR UAV in full-mode flight is studied. First, based on the typical flight profile of SR UAV when performing missions, using the theory and method of fuzzy mathematics, the T-S flight dynamics model of SR UAV in full-mode flight is established by synthesizing the flight dynamics model of each flight mode. Then, an explicit model tracking and parameter adjusting control system based on fuzzy theory is designed to enhance the stability of the inner loop of SR UAV in full-mode flight, which effectively reduces the coupling between axes and improves the control quality of the system. Finally, the outer loop control system is designed by using classical control method, and the control law of SR UAV in full-mode automatic flight is obtained. The simulation results show that the proposed control system design method is feasible and effective, which lays a solid foundation for the subsequent engineering implementation of the SR UAV.

Renewable DNA Proportional-Integral Controller with Photoresponsive Molecules.

A molecular robot is an intelligent molecular system. A typical control problem of molecular robots is to maintain the concentration of a specific DNA strand at the desired level, which is typically attained by a molecular feedback control mechanism. A molecular feedback system can be constructed in a bottom-up method by transforming a nonlinear chemical reaction system into a pseudo-linear system. This method enables the implementation of a molecular proportional-integral (PI) controller on a DNA reaction system. However, a DNA reaction system is driven by fuel DNA strand consumption, and without a sufficient amount of fuel strands, the molecular PI controller cannot perform normal operations as a concentration regulator. In this study, we developed a design method for a molecular PI control system to regenerate fuel strands by introducing photoresponsive reaction control. To this end, we employed a photoresponsive molecule, azobenzene, to guide the reaction direction forward or backward using light irradiation. We validated our renewable design of the PI controller by numerical simulations based on the reaction kinetics. We also confirmed the proof-of-principle of our renewable design by conducting experiments using a basic DNA circuit.

Parameter Optimal Iterative Learning Control Design: from Model-based, Data-driven to Reinforcement Learning

Iterative learning control (ILC) is a high-performance control design method for systems operating in a repetitive fashion by learning from past experience. Our recent work shows that reinforcement learning (RL) shares many features with ILC and thus opens the door to new ILC algorithm designs. This paper continues the research by considering a parameter optimal iterative learning control (POILC) algorithm. It has a very simple structure and appealing convergence properties, but requires a model of the system. We first develop a data-driven POILC algorithm without using model information by performing an extra experiment on the plant. We then use a policy gradient RL algorithm to design a new model-free POILC algorithm. Both algorithms achieve the high-performance control target without using model information, but the convergence properties do differ. In particular, by increasing the number of function approximators in the latter, the RL-based model-free ILC can approach the performance of the model-based POILC. A numerical study is presented to compare the performance of different approaches and demonstrate the effectiveness of the proposed designs.

Semi-active vibration control of structural systems with a variable inerter

We propose a design method of semi-active vibration control systems using a variable inerter for structural systems subject to seismic disturbances. The inerter is a vibration control device generating resistance force proportional to the relative acceleration between both ends. In the variable inerter, the inertia mass of the inerter can be changed by a command signal in realtime. The mathematical model of the variable inerter is defined considering the dynamic delay of the inertia mass change subject to the command signal. For the dynamic model of a structural system with the variable inerter, we propose a semi-active control law based on a reference active control system. The reference active control system is a virtual system showing the ideal control performance. In the proposed semi-active control law, the variable inertia mass is changed by considering a predicted control output, the predicted error between the control output of the semi-active and reference active control systems, and the predicted reaction force of the inerter. The characteristic of the reference active control is optimized so that the control performance of the resulting semi-active control system is close to that of the best control systems among the passive off (without control), passive on (maximum inertia mass), and reference active control systems. A simulation study shows the effectiveness of the proposed semi-active control method.

Algorithmic Method for the Design of Sequential Circuits with the Use of Logic Elements

This article presents issues related to the design of sequential control systems. The algorithmic design method of sequential control systems is discussed, which allows the design of a diagram of any sequential system. The algorithmic method uses the description in the form of a connection formula. The connection formula defines the order of actuations of driver elements, in this case actuators. The algorithmic method is used, among others, for systems with actuators cooperating with distributors controlled electrically on both sides. The process of creating a system graph has been characterized. The operation of the system has been shown graphically. On the basis of the created graph describing the functions of signal processing, a method for rapid programming of sequential electro-pneumatic systems with the use of logic elements has been provided. A separate dedicated timing unit has been used to perform memory functions. Its operation is based on successive states, in such a way that the next state deletes the previous one. Graph-based systems have been validated through simulation using Festo’s FluidSim computer-aided design software.

New Normal After Education Game Design Pandemic Uses Approaches Agile Scrum Application of Finite State Machine (FSM) Method

Game is an application that infers human behavior into software, and players who play the game feel they are entering the game world. Games can be used as a medium for information and education. The current rise of Covid-19 requires every individual to implement health protocols in their daily life. This term is called new normal. New normal is a change in behavior to continue carrying out normal activities but with the addition of implementing health protocols to prevent Covid-19 transmission. Unfortunately, in everyday life, the application of the new normal is less effective so that in one area, new cases have emerged and the PSBB must be re-applied. The new normal themed educational game can be a fun information medium for the community, with the New Normal After Pandemic educational game, it is hoped that it can educate the public in implementing health protocol rules. This game was created using Construct 2 software because it is based on HTML 5 which is specifically for 2D platforms. 2D designs are created using Corel Draw X7, Easy Paint Tools SAI and Adobe Photoshop. The final result of this study is a game application that applies the FSM (Finite State Machine) control system design method in each level rule and uses the Agile Scrum system development method with a process of 2x sprint iterations

Event-triggered H–/L∞ fault detection observer design for discrete-time Lipschitz nonlinear networked control systems in finite-frequency domain

This paper proposes an event-triggered fault detection observer (FDO) design method for discrete-time Lipschitz nonlinear networked control systems (NCSs) in finite-frequency domain. First, a discrete event-triggered transmission scheme is proposed to mitigate the utility of limited network bandwidth. Second, with the aid of a reformulated Lipschitz property, the nonlinear error dynamics are converted into a linear parameter varying (LPV) networked system model. Third, based on this model, the finite-frequency index is used to measure the worst-case fault sensitivity performance and the norm from unknown disturbance to residual is used to measure disturbance robustness performance. Next, a residual evaluation and a dynamic threshold are synthesised based on the norm. Furthermore, sufficient conditions of the FDO design are derived and transformed by a set of linear matrix inequalities (LMIs). The proposed FDO design method can significantly reduce the data transmission to relieve the communication pressure, and can also achieve better FD performance than the full frequency domain. Finally, A numerical example is provided to demonstrate the effectiveness and applicability of the proposed design approach.

Modular substation intelligent control cabinet temperature control system

When the temperature control system of intelligent control cabinet of modular substation is designed by the current method, the PID controller is not improved, and there are problems such as low temperature prediction accuracy, low temperature tracking accuracy and poor control effect. The design method of temperature control system of intelligent control cabinet of modular substation is proposed. Through FPGA, input circuit, output circuit, man-machine interface, frequency division module five parts constitute the modular substation intelligent control cabinet temperature control system framework, in the temperature control system combined with the predictive function control algorithm to achieve the modular substation intelligent control cabinet temperature control system software system design. The experimental results show that the designed system can control the terminal temperature stably and reduce the temperature fluctuation to a small extent.

A Design Method for Low-cost and SOPC-based Flexible Lifting Control System

To efficiently reduce the development and production costs of the intelligent lifting control system, we introduce a design method for the intelligent lifting system with client-server architecture. We replace DSP processor core or DSP (Digital Signal processor) core with Nois II soft-core processor so that the design and production costs can be effectively cut. By replacing DSP processor or DSP processor core with Nois II soft-core processor, the design and production costs can be significantly reduced. In our design, loop vector control units work as a server processor, and a central computing unit with four independent multipliers and two adders is employed, with the implementation method based on a state machine. The experimental results prove effective in reducing resource requirements for FPGA (Field Programmable Gate Array), show that the proposed method can be successfully applied to the implementation of a complete intelligent flexible lifting control system on a low-end Altera Cyclone FPGA, and servo motor control achieves better dynamic performance

Temperature Control System of Medical Instrument Based on Dual Threshold Hysteresis Comparison Circuit

The paper presents a design method of temperature control system of medical instrument based on dual threshold hysteresis comparison circuit. The system adopts a negative temperature coefficient thermistor as the temperature sensor and a thermoelectric cooler as the control object. By means of this method, the working temperature in the medical instrument ranges from two degrees centigrade to four degrees centigrade accurately. According to the test results the design scheme is optimized and improved. The design method is scientific, effective and economic by experiments.

Multi-objective visual design method of control system for synchronous motor drives

Design of current controller for synchronous motor drive system can hardly achieve the desired time- and frequency-domain specifications simultaneously, therefore a multi-objective visual design method is proposed. D-partition technique, which is suitable for nonlinear system, is applied to obtain the controller parameters stable region. In order to improve the stability and dynamic property of synchronous motor drives, frequency-domain specifications such as gain margin and phase margin, time-domain specifications such as overshoot and settling time are considered. Firstly, these specifications are analyzed using three-dimensional (3D) visualization technique. The 3D graphs of gain margin, phase margin, overshoot and settling time changing with controller parameters in the stable region are plotted, respectively. Furthermore, to meet the desired requirements, a multi-objective visual design method is proposed and an optimization region is obtained, which shows the relationship between the desired requirements and the controller parameters. Finally, optimal controller parameters can be derived from the optimization region which meet the requirements of practical engineering. The design process is intuitive and clear, meanwhile time- and frequency-domain specifications can be achieved simultaneously without trial-and-error. Simulation and experimental results verify the proposed method of effective and practical.

Research on a design method of pneumatic logic control system

Aiming at the complex characteristics of the sequential logic control system design, such as X-D diagram and karnaugh map method, a design method based on stepper module was proposed, the procedure of which does not need to be checked and corrected. The design of different pneumatic circuits was carried out with the automatic drilling machine as the application object. First, a stepper module composed of a two-position three-way valve and a dual-pressure valve was constructed, and its structure principle was analyzed in detail. Next, three kinds of stroke programs were listed by analyzing the working process of automatic drilling machine, which were multi-cylinder single reciprocating, multi-cylinder multi reciprocating and multi-cylinder multi-section reciprocating stroke program, and the pneumatic circuit control system was designed by the stepper module method. Finally, the pneumatic circuit was simulated and analyzed using the software Fluid-SIM. The simulation results showed that each actuator can complete the corresponding actions according to the design requirements, which verified the correctness and reliability of the stepper module design method. This work would provide a fast and effective method for the design of the sequential logic control system.

Nonlinear Control System Design of an Underactuated Robot Based on Operator Theory and Isomorphism Scheme

The number of actuators of an underactuated robot is less than its degree of freedom. In other words, underactuated robots can be designed with fewer actuators than fully actuated ones. Although an underactuated robot is more complex than a fully actuated robot, it has many advantages, such as energy, material, and space saving. Therefore, it has high research value in both control theory and practical applications. Swing-up is a mechanism with two links, which mimics a gymnast performing a horizontal bar movement. Over the past few decades, many sufficiently robust control techniques have been developed for a fully actuated robot but almost none of them can be directly applicable to an underactuated robot system. The reason is that such control techniques require certain assumptions that are valid only for fully actuated robot systems but not for underactuated ones. In this paper, a control system design method for underactuated robots based on operator theory and an isomorphism scheme is first proposed. Bezout identity is designed using isomorphism. The effectiveness of the design method is confirmed by simulation. The simulation results show that the performances, such as robust stability and response time, of an underactuated robot control system are improved.