Non-linear mechanical system type fixed time control method considering actuator faults

Abstract

The invention relates to a non-linear mechanical system type fixed time control method considering actuator faults, which designs a robust control technology of a type of fixed-time convergence so that the system not only can adaptively process the fault problem of an actuator, but also can ensure that the mechanical system reaches a stable state within a time range given by a user, and the steady-state performance and the transient-state performance of the system are both within pre-designed performance indexes. The method has the following advantages: the mechanical system enters the steadystate before this time, namely, tracking an expected track with high precision is achieved to ensure the successful completion of a task; the self-adaptive law can achieve self-adaptive compensation autonomously and ensure the stability of the mechanical system; the transient parameters (such as convergence time and convergence rate) and steady-state parameters (steady-state tracking error) of themechanical system can be designed independently by the technical users, the parameters are closely combined with engineering technical indexes, so that the method is very suitable for engineering application.

Description

technical field [0001] The invention belongs to the technical field of robust control of mechanical systems, and relates to a fixed-time control method for non-linear mechanical systems considering actuator faults. Background technique [0002] Many practical mechanical systems can be modeled in the form of Euler-Lagrange (EL) systems, such as robotic systems, literature: Karayiannidis Y, Doulgeri Z.Model-free robot joint position regulation and tracking with prescribed performance guarantees[J].Robotics and Autonomous Systems, 2012, 60(2): 214-226.; Spacecraft systems, literature: Wei C, Luo J, Dai H, et al. Adaptive model-free constrained control of postcapture flexible spacecraft: a Euler–Lagrange approach[J]. Journal of Vibration and Control,2018,24(20):4885-4903.; Energy transmission system, literature: Lee T S. Lagrangian modeling and passivity-based control of three-phase AC / DC voltage-source converters[J].IEEE Transactions on Industrial Electronics,2004,51(4):892-90...

AI Technical Summary

Problems solved by technology

However, most of the existing research results have not considered a key issue: how to design the control performance of mechanical systems a priori

However, this method also has implementation problems: due to the existence of fractional-order states, when the system works in a steady state, external measurement noise and interference are easily amplified by the controller, resulting in problems such as low steady-state accuracy and chattering in the system

However, this method also has problems: the traditional performance boundary design method can only guarantee that the system is exponentially convergent

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