In this paper, based on the nonlinear disturbance observer, the model-following sliding mode controller is designed for the UAVs flight control system. First, the nonlinear disturbance observer is designed to observe the disturbance of the system, which converts the observed disturbance into the corresponding input. Then, the advantages of model following and sliding mode control are employed. Through Linear Quadratic Regulator method, the sliding surface is designed to make the sliding mode have good dynamic characteristics and to eliminate the steady state error. The simulations results demonstrate that the UAVs flight control system using the proposed method not only reduces the chattering, but also achieves satisfactory model following performance.
In this paper, a direct adaptive control scheme is proposed for a faulty helicopter using the outer loop compensation technique. Firstly, the model reference adaptive control is introduced, which is used for designing the fault tolerant control system of helicopter. Secondly, an outer-loop adaptive compensator is designed for improving the self-repairing capability of the model reference adaptive control approach. Finally, simulation results on a linear varying-parameter helicopter control system are given to illustrate the effectiveness and feasibility of the presented direct adaptive control approach using outer loop compensation technique.
High hydrostatic pressure (HHP) is a widely used method for sterilizing and processing food, but it can release intact intracellular components, including allergenic proteins, into the food matrix, which poses a risk of sensitization. In this study, we investigated the leakage of allergenic protein enolase from Saccharomyces cerevisiae during HHP treatment. Results showed a gradual increase in enolase leakage with increasing HHP treatment. Enolase was found to be altered in advanced structure and bound to other intracellular substances, leading to regular allergenicity in spilled material. The kinetics of enolase leakage from HHP-treated Saccharomyces cerevisiae were established, and a mathematical model was developed to predict the risk of allergen leakage from HHP-treated food. These findings have important implications for safety risk warning of allergens during HHP treatment and for promoting HHP technology in the food industry.
In order to achieve the direct self-repairing control for faulty UAVs, a kind of direct adaptive control based on the paralleled integral and fuzzy control is proposed to the fault model of a UAV's flight control system. First, adopting the model reference adaptive control law based on fuzzy control, the control is realized by analyzing the flight control performance when some complex faults occur. Then, the method of a new direct self-repairing control is formulated by the paralleled integral and fuzzy control. Consequently, the stable error, the properties of response, and robustness are improved. The simulation results are given to illustrate that a good dynamic performance of the flight control system with large faults can be maintained with the proposed method.
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