A Disturbance Upper Bound Adaptive Fractional Order Global Terminal Sliding Mode Model-Free Control Method

Abstract

The invention discloses a model-free control method for a disturbance upper bound self-adaptive fractional-order global terminal sliding mode, including, according to the energy conservation law, establishing a hypersonic vehicle aerothermal ground simulation system mathematical model and a super-local model for model-free control; The time-delay observer predicts the unknown disturbance of the hypersonic vehicle aerothermal ground simulation system; based on the fractional-order global terminal sliding mode surface, the high-frequency chattering of the hypersonic vehicle The upper bound of the network disturbance adaptively calculates the equivalent control rate and approach rate, and completes the fractional order global terminal sliding mode control. The overall design of the present invention weakens the chattering phenomenon in the approaching process, and the introduced fractional order feedback item can increase the convergence speed and stability by changing the value of the fractional order, and reduce the steady-state error. The adaptive rate of the neural network is designed to track the upper bound of the perturbation error.

Description

technical field [0001] The invention relates to the technical field of aerospace automation, in particular to a disturbance upper bound adaptive fractional order global terminal sliding mode model-free control method. Background technique [0002] During the flight, the interaction between the hypersonic vehicle and the incoming flow will generate a lot of heat due to friction on the wall of the vehicle. The choice of wall material determines whether the vehicle can withstand the high temperature environment and whether the interior of the vehicle can work normally. It is obviously unrealistic to use the same material for the entire aircraft, but the ground simulation environment test can simulate the thermal environment during flight, and the appropriate material can be selected at different heated positions according to the thermal environment. [0003] Common ground simulation devices include wind tunnel test and radiant heat test. The wind tunnel test can truly simulate...

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Problems solved by technology

[0004] The ground simulation system heated by quartz lamps has the characteristics of nonlinearity and instability. The traditional PID algorithm is susceptible to external interference in industrial applications, so it is difficult to obtain satisfactory temperature control performance.

The terminal sliding mode control is suitable as a control method for controlling the quartz lamp heater because of its insensitivity to disturbances and uncertainties, but there are several deficiencies in the terminal sliding mode control: stage, there is inevitably chattering phenomenon; local terminal sliding mode control has singular problems

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