High performance nonlinear adaptive control of temperature in cryogenic wind tunnel

Temperature control in a cryogenic wind tunnel is the key to realizing finely controlled Reynolds number close to true flight. This study deploys the L1 adaptive control methodology to ensure the total temperature profile of the cryogenic wind tunnel tracks a specified reference trajectory. After introducing a non-linear model of a cryogenic wind tunnel and a linear temperature model, a linear–quadratic–Gaussian (LQG) controller is implemented as the baseline controller. The L1 adaptive controller with piecewise constant adaptive law is used as an augmentation to the baseline controller to cancel the matched and unmatched uncertainties within the actuator’s bandwidth. By introducing two modifications to the standard L1 adaptive controller, which are the transportation delay modelling in the state predictor and the non-linear state dependent filter, the L1 adaptive controller improves the performance of the baseline controller in the presence of uncertainties in temperature control, guaranteeing proper stability and delay margin. The simulation results and analysis demonstrate the effectiveness of the proposed control architecture. The main contribution of this paper lies in the first applications of L1 adaptive control to the wind tunnel control problem and the non-linear state dependent filter in L1 adaptive control structure.

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Nonlinear Adaptive Control of High Performance Aircraft Using Neural Networks

10.1109/aerocs.1993.720971 ◽

2005 ◽

Cited By ~ 2

Author(s):

T. Juneau ◽

J.K. Hedrick

Keyword(s):

Neural Networks ◽

Adaptive Control ◽

High Performance ◽

Nonlinear Adaptive Control ◽

High Performance Aircraft

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Nonlinear L1 adaptive control of stagnation pressure in a cryogenic wind tunnel

Advances in Aerodynamics ◽

10.1186/s42774-019-0024-5 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

Rusong Zhu ◽

Mingwei Xie ◽

Daxiong Liao ◽

Gengsheng Tang ◽

Wen Gai

Keyword(s):

Adaptive Control ◽

Mach Number ◽

Wind Tunnel ◽

Nonlinear Systems ◽

Feedforward Control ◽

Pressure Control ◽

Stagnation Pressure ◽

Control Architecture ◽

Adaptive Feedforward ◽

Cryogenic Wind Tunnel

AbstractCryogenic wind tunnel is a sophisticated aerodynamics ground test facility, which operates in cryogenic temperature with injection of liquid nitrogen. The multi-variable, nonlinear and coupled dynamics existing between the temperature, pressure and Mach number in the tunnel, poses great challenges for the effective control of the tunnel. L1 adaptive control is a new control methodology developed in recent years with good robustness properties, which has good potentials to address these challenges. But this control method does not provide full adaptive feedforward control in its generic structure. In the paper, adaptive feedforward control action is introduced into the standard L1 adaptive control architecture for nonlinear systems in the presence of matched un-modeled dynamics. This new control structure is applied to the stagnation pressure control in a cryogenic wind tunnel, which could also be used for the control of temperature and Mach number in the tunnel. This new method could effectively compensate known disturbances with linear gain uncertainty, which occur in the nonlinear systems, while retaining the closed-loop control performance of L1 adaptive control. After the proof and discussions on the stability of this method, simulations of the stagnation pressure control in the wind tunnel are presented. The results and analysis demonstrate the effectiveness of the proposed control architecture.

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A Check Tool for the Half-Model Balance of the Cryogenic Wind Tunnel Cologne DNW-KKK

51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition ◽

10.2514/6.2013-417 ◽

2013 ◽

Author(s):

Junnai Zhai

Keyword(s):

Wind Tunnel ◽

Cryogenic Wind Tunnel

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Characteristic model-based adaptive control for cryogenic wind tunnels

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331220960652 ◽

2020 ◽

pp. 014233122096065

Author(s):

Chenhui Yu ◽

Fei Liao ◽

Haibo Ji ◽

Wenhua Wu

Keyword(s):

Reynolds Number ◽

Wind Tunnel ◽

Flow Field ◽

Control Problem ◽

Mimo System ◽

Adaptive Controller ◽

Characteristic Model ◽

Model Based ◽

Field Control ◽

Cryogenic Wind Tunnel

With the increasing requirement of Reynolds number simulation in wind tunnel tests, the cryogenic wind tunnel is considered as a feasible method to realize high Reynolds number. Characteristic model-based adaptive controller design method is introduced to flow field control problem of the cryogenic wind tunnel. A class of nonlinear multi-input multi-output (MIMO) system is given for theoretical research that is related to flow field control of the cryogenic wind tunnel. The characteristic model in the form of second-order time-varying difference equations is provided to represent the system. A characteristic model-based adaptive controller is also designed correspondingly. The stability analysis of the closed loop system composed of the characteristic model or the exact discrete-time model and the proposed controller is investigated respectively. Numerical simulation is presented to illustrate the effectiveness of this control method. The modeling and control problem based on characteristic model method for a class of MIMO system are studied and first applied to the cryogenic wind tunnel control field.

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