A design method of memory h∞ output feedback controller for time-delay lpv system

Abstract

The invention discloses a time-delay LPV system with memory H ∞ The design method of the output feedback controller includes the following steps: First, the vibration control system of the milling machine milling process is abstracted into a time-delay LPV model, and the memory H is obtained through model conversion. ∞ The standard form of the output feedback controller to solve the problem; secondly, the introduction of the slack matrix variable and the quadratic Lyapunov functional will satisfy the expected performance index with memory H ∞ The output feedback control problem is transformed into a convex optimization problem based on linear matrix inequality; then, a new convex optimization method is selected to give a finite-dimensional parameterized linear matrix inequality at the vertices of a given multicellular LPV system ; Finally, through the linear matrix inequality, get the memory H ∞ Output feedback controller K. By using the method provided by the present invention, it is possible to design a robust and stable memory H with interference attenuation ∞ The output feedback controller makes the tool always have good dynamic performance during the cutting process.

Description

technical field [0001] The invention relates to the field of vibration control in the milling process of a milling machine, in particular to a time-delay LPV system with memory H ∞ Output feedback controller design method. Background technique [0002] In the machining process, the precision and surface roughness of the machined workpiece, the service life of the tool and the machine tool, and the machining cycle are all affected by the tool vibration. Therefore, the vibration control of machining has become an important issue in the machining process; [0003] The LPV theory was first proposed by Shamma in 1988, and its main purpose is to extend the existing linear control design basis to nonlinear and time-varying systems; in the existing technology, for the milling process of a milling machine, the general The vibration control system is abstracted into a time-delay LPV system, and then a corresponding controller is designed for the time-delay LPV system to reduce the im...

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Problems solved by technology

[0004] However, the existing controller design methods generally adopt the robust H ∞ State feedback technology, although this technology can ensure that the system satisfies the H ∞ performance indicators, but because the state feedback needs to obtain the state information of the controlled object, in many practical problems, the state variables considered are a set of variables that describe the internal information of the system, and often cannot be directly measured; sometimes even if the state of the system is It can be directly measured, but considering factors such as the cost of implementing control and the reliability of the system, if the output feedback of the system can be used to meet the performance requirements of the closed-loop system, it is more suitable to choose the control method of output feedback; Since the memory state feedback controller does not introduce the past state information of the system, the influence of the time delay on the system cannot be effectively controlled, so that the cutting tool cannot work accurately and smoothly; therefore, there are many defects in the existing controller design method

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