Time delay compensation method with double-control function between transmitter (controller) and actuator

Abstract

The invention provides a time delay compensation method with a double-control function between a transmitter (controller) and an actuator, belonging to the interdisciplinary field between network communication technology and control technology. The invention replaces the network time delay compensation model between the transmitter (controller) node and the actuator node with the network data transmission process between the true transmitter (controller) node and the actuator node, thereby avoiding the measurement, estimation or identification of the network data transmission time delay between nodes and ignoring the requirement for node clock signal synchronization. When the controlled object preestimates a deviation between the model parameter and the true model parameter, a second controller can enhance the robustness and antijamming capacity of the system. The method can be used for reducing the influence of network time delay on the system stability and improving the quality of the system control performance. The invention is suitable for network control system time delay compensation and control when the mathematical model of the controlled object is given or not completely given and the network only exists between the transmitter (controller) node and the actuator node.

Description

technical field [0001] The invention relates to a network time delay compensation method with dual control functions in which the network only exists between a transmitter (controller) node and an actuator node, and belongs to the technical field of network control systems. Background technique [0002] A closed-loop feedback control system based on a real-time communication network is called a networked control system (Networked control systems, NCS), and a typical structural block diagram of a networked control system suitable for the present invention is as follows figure 1 shown. [0003] The network control system fully embodies the development of the control system in the direction of networking, integration, distribution, and node intelligence, realizes network resource sharing, and increases the flexibility and reliability of the system. However, due to the limited network bandwidth, information Transmission will inevitably produce network delay, the existence of de...

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Problems solved by technology

[0007] Since there is an exponential term e of the network delay τ in the denominator of the closed-loop transfer function shown in equation (1) -τs , the existence of time delay will deteriorate the control performance quality of the system, and even cause the system to lose stability, and in severe cases, the system may fail.

[0008] The key to reducing the impact of delay on system stability is whether the exponential term e of the network delay τ between the transmitter (controller) node and the actuator node can be realized -τs It is removed from the denominator of equation (1), that is, the exponential term of the network delay is not included in the closed-loop characteristic equation, and then the compensation for the network delay is realized. However, to realize the compensation for the network delay, we must first know The size of the network delay. At present, the method usually used at home and abroad is to compensate the influence of the delay on the system stability by measuring the network delay τ. However, because the accurate measurement of the network delay needs to satisfy the node clock signal Synchronization requirements. If hardware is used to realize the complete synchronization of node clock signals, a large economic investment is required; if software is used to correct clock signals, it is difficult to achieve because the correction signals may be affected by network delays when they are transmitted between nodes. The node clocks are completely synchronized; if the method of estimating, identifying or predicting the network delay is used to obtain the size of the network delay, the accurate probability distribution of the network delay must be known, or an accurate mathematical model, but due to the network delay The size may be random or time-varying, and its value is related to factors such as specific network protocols, network load, and network topology, and there may be deviations in the estimation or identification of network delay.

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