编号 3 (2022)
Analysis and Design of Control Systems
Tracking system DESIGN for a single-link sensorless manipulator under nonsmooth disturbances
摘要
The controlled plant is a single-link manipulator having an elastic connection to a DC motor and operating under uncertainty and incomplete measurements. The problem is to design a discontinuous feedback control for tracking a given reference signal of the plant’s angular position. The angular position and velocity of the manipulator are not available for measurements; the sensors are located only on the drive; parametric and exogenous disturbances affecting the manipulator are nonsmooth and cannot be directly suppressed by control applied to the actuator. Within the block approach, a decomposition procedure is developed to design a nonlinear local feedback control. This control ensures the controlled variable’s invariance with respect to uncertainties unmatched with the control action. A state observer of reduced order is constructed to estimate the angular position and velocity of the manipulator required for feedback design. The state variables in this observer are estimated using the principle of restoring exogenous disturbances by their action on the controlled plant. With this principle, a dynamic model of exogenous disturbances is not needed. In both problems (control and observation), S -shaped bounded continuous local feedbacks are used (smooth (sigmoidal) and nonsmooth (piecewise linear) local feedbacks, respectively). These local feedbacks suppress bounded disturbances acting with them through the same channel. The algorithms developed below do not require real-time identification of parametric and exogenous disturbances. However, they stabilize the observation and tracking errors with some accuracy. The effectiveness of the dynamic feedback is validated by the results of numerical simulation.
Control Sciences. 2022;(3):3-15
3-15
Control in Social and Economic Systems
MANAGEMENT OF TECHNOGENIC SAFETY BASED ON A RISK-ORIENTED APPROACH
摘要
This paper proposes a managerial decision algorithm based on the developed risk assessment methodology with multidimensional statistical analysis. The methodology allows calculating an acceptable level of risk, which can be used in regulatory documents. The decision algorithm is integrated into the information system of territorial risk and security management. The industrial agglomerations of Siberia are chosen as the object of research, and their main types of technogenic hazards are analyzed. The complex risk is assessed using statistical data on man-made dangerous events, emergencies, material damage, and fatal outcomes from the official database (the Emercom of Russia). According to risk factor analysis, the main technogenic load in territorial units is due to fire and explosive events. The inverse problem is solved, showing the need to reduce the main risk factors for achieving an acceptable level. Minimizing the complex technogenic territorial risk is a management problem with two criteria: the minimum number of fatal outcomes and the minimum amount of damage. Within the complex risk assessment approach, the problem is solved by proposing preventive measures to improve territorial security.
Control Sciences. 2022;(3):16-28
16-28
An approach TO COMPARe ORGANIZATION MODES OF ACTIVE AGENTS and CONTROL METHODS
摘要
When interacting, active agents can behave independently, cooperate, or have hierarchical relations. In turn, a hierarchical impact may be exerted by administrative or economic methods with or without feedback. These organizational modes and control methods are systematically described based on game-theoretic models with different information structures without uncertainty. It seems crucial to compare the payoffs of separate agents quantitatively with social welfare under the organization modes and control methods. A methodology is proposed to build the systems of social and individual preferences in normal form games and determine shares when allocating the cooperative payoff. A system of relative efficiency indices is developed for detailed quantitative assessment. This methodology is illustrated by several Cournot oligopoly models.
Control Sciences. 2022;(3):29-39
29-39
Information Technology in Control
ASSESSMENT OF OPERATOR AUTHENTICATION METHODS IN INDUSTRIAL CONTROL SYSTEMS
摘要
This paper considers the authentication of operators in instrumentation and control (I&C) systems for industrial facilities. The main emphasis is on such systems for critical facilities, on an example of nuclear power plants (NPPs). Authentication methods known for public information systems (password, token, and biometrics) are surveyed, and their applicability in typical operating conditions of an I&C operator is analyzed. The analysis includes experimental testing of password and biometric authentication methods and an expert assessment of their advantages and disadvantages for I&C systems. According to the testing results, all the methods under consideration have somewhat worse values of the false rejection rate (FRR) compared with the known characteristics from available sources. The best results are shown by biometric identification by the face oval. However, the percentage of FRR for this method is significant, which can affect the availability of the control function for a legitimate operator. As concluded, a promising approach for industrial control systems is to implement multi-factor authentication: token or password protection for blocking authentication jointly with biometric authentication by the face oval with a non-blocking security policy.
Control Sciences. 2022;(3):40-54
40-54
THE SIMULTANEOUS START OF ACTIONS IN A DISTRIBUTED GROUP OF AUTOMATIC DEVICES: A DECENTRALIZED CONTROL METHOD WITH A SIGNAL REPEATER
摘要
This paper proposes a method for accelerating decentralized synchronization processes in the distributed control of a group of stationary or mobile automatic objects. With this method, the objects pass to specified states or affect the environment simultaneously or with required time delays. Some examples of such objects include actuators, computers in a computing cluster, distributed data processing facilities in supercomputers, and mobile robots. The object’s action depends on the current state of all objects and the environment. The actions should start with minimum delay after detecting the possibility to perform them. Arbitrarily located sources of executive commands and their receivers are synchronized by exchanging signals and messages between objects through an intermediary (a signal repeater). Means are used to accurately measure the time intervals of signal transfer between each object and the repeater. Group operations are used to accelerate synchronization processes. These operations involve a large number of objects simultaneously. The object’s data are used in operations simultaneously. Data are processed during their transmission without extra time. Operations are executed by network devices of the system objects and the common network device without any computing facilities (the repeater).
Control Sciences. 2022;(3):55-64
55-64