A Vibration Suppression Algorithm for Space Flexible Manipulator

Abstract

The invention discloses a vibration suppression algorithm of a spatial flexible mechanical arm. The algorithm is implemented as follows: S1, a dynamic model of a rigid-flexible coupling mechanical arm system is established under a generalized coordinate system; S2, a generalized variable in the dynamic model of the rigid-flexible coupling mechanical arm system is decomposed to obtain a quick-changing parameter and a slow-changing parameter; S3, corresponding sub systems are established for the quick-changing parameter and the slow-changing parameter and corresponding control laws are configured; and S4, the control laws of the quick-changing parameter and the control law of the slow-changing parameter are combined, thereby localizing the rigid-flexible coupling mechanical arm system and carrying out vibration suppression. According to the invention, the dynamic model of the rigid-flexible coupling mechanical arm system is established and is decomposed into the quick-changing and the slow-changing sub systems with different dimensions; and the rigid attitude motion state and the flexible vibration state of the platform are separated and controllers are designed respectively to carry out combined controlling. Therefore, a flexibility vibration control problem of in-orbit flexible mechanical arm operation is solved.

Description

technical field [0001] The invention relates to the technical field of attitude control of on-orbit maneuvering spacecraft, in particular to a vibration suppression algorithm of a space flexible manipulator. Background technique [0002] my country's spaceflight "three-step" strategy (manned spaceflight, air docking, and space station establishment) is being implemented smoothly. The astronauts' out-of-cabin activities have been completed. The next step is to realize the docking of spacecraft and the construction of the space station. Developing countries like our country where space funding activities are not very abundant, it is more appropriate to use space flexible manipulators for space operations, which can save huge expenses while avoiding unnecessary casualties. The research on this key technology has important theoretical value and engineering application value. [0003] When the spatially flexible manipulator performs the operation task, not only the controller is...

AI Technical Summary

Problems solved by technology

However, for a space manipulator system with a flexible arm, the design of its vibration controller faces the following difficulties: First, the transfer function between the drive torque input at the joint end and the end position output at the end of the arm has a non-minimum phase characteristics, especially when there is a positive input on the joint axis and a negative displacement at the end; secondly, the operating load and boundary conditions of the manipulator are time-varying, and the vibration modal parameters are time-varying and uncertain Thirdly, the modal truncation technique during modeling will cause control overflow and observation overflow, resulting in the excitation of the remaining modes, making the control performance worse or even unstable

These factors make it difficult to realize the precise positioning control of the end of the flexible manipulator. If only the joint position is controlled as the output of the system, although the transfer function can be converted into the minimum phase, it is obviously impossible to suppress the vibration, which will definitely cause a lot of damage. Dynamic tracking error; if the controller is designed with the nominal truncated model of the system, its robustness must be guaranteed

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