Research on a New Azimuth Control Method for Stratospheric Balloon-borne Gondola System

摘要

For a class of non-matching uncertain nonlinear system such as stratospheric balloon-borne gondola azimuth control system, a new robust adaptive multiple sliding mode controller is proposed.In this control method, the virtual and the practical control variables are obtained by designing the multiple sliding modes step-by-step.For avoiding the chattering problem generated by discontinuous input, the traditional sign function is replaced by hyperbolic tangent function.Meanwhile, the CMAC neural network is used to approximate the system uncertainties and the derivative of virtual control input online, which can reduce the conservation of controller parameters design.The system stability analyses show that the control method can guarantee that the output tracking error and slide modes asymptotically convergent to boundary layer.The simulation results show that the controller has higher tracking accuracy, and stronger robust to nonlinear and uncertainty of system, and it also can be applied to other similar non-matching uncertain nonlinear systems.