Self-adaptive control method of rapid attitude error convergence for small unmanned helicopter

Abstract

The invention relates to a nonlinear control method for a small unmanned helicopter, especially to an attitude control method for the small unmanned helicopter based on a second-order self-adaptive terminal sliding mode controller, and realizes rapid attitude error convergence and maintains relatively accurate attitude tracking control effect and relatively high system robustness under the condition that external interference of the small unmanned helicopter exists. According to the technical scheme of the invention, a second-order self-adaptive terminal sliding-mode method is applied to attitude system control of the small unmanned helicopter under the condition that the small unmanned helicopter has external interference. The method comprises the following steps that 1) an attitude dynamics model of the small unmanned helicopter is determined; 2) an attitude angle tracking error is defined, and a dynamics error model is arranged; 3) a control law is designed; and 4) self-adaptive control gain is designed. The method of the invention is mainly used for nonlinear control of the helicopter.

Description

technical field [0001] The invention relates to a nonlinear control method for a small unmanned helicopter, in particular to an adaptive control method for a small unmanned helicopter based on a second-order adaptive terminal sliding mode. Specifically, it involves a fast convergence adaptive control method for attitude errors of small unmanned helicopters. Background technique [0002] As a kind of rotor UAV, small unmanned helicopter has the advantages of vertical take-off and landing, good maneuverability, fixed-point hovering, and low-altitude flight. It is mainly used in military and civilian fields such as military reconnaissance, search and rescue, meteorological observation, pesticide spraying, and architectural surveying and mapping. The unmanned helicopter system has the characteristics of static instability, nonlinearity, strong coupling, and strong uncertainty. The design of its controller has always been a hot and difficult point of research at home and abroad....

AI Technical Summary

Problems solved by technology

Although the performance of the traditional sliding mode control is excellent, there are still some defects. First, the design of the sliding mode surface adopts the linear combination form of the system state, so that the system state finally reaches asymptotic convergence, which is not suitable for some control systems with high control accuracy. Occasion required

Second, due to the existence of discontinuous switching items, it will cause the chattering phenomenon of the control input

If the control gain is selected too small, the control ability will be lost and the system will be unstable; if the control gain is selected too large, it will cause large chattering, waste control energy and affect the control accuracy

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