A new optimization control method, which is based on the optimization employing Bezier curves of control variables, is proposed to improve engine thrust response performance. The minimum of the time consumption for control variables changing from start to end point is selected as objective function. Unlike conventional methods, the optimization variables are altered to the Bezier curves of the control variables in this scheme. This new acceleration optimization control only establishes one optimization problem for the overall acceleration process instead of establishing a series of sub optimization problems, which is usually adopted by conventional optimization controls. Hence, the proposed method is easier to overcome the disadvantage of the conventional ones, which just search for the optimal engine performance in local time period. Finally, for comparisons, the simulations for the proposed method and the conventional one have been both conducted. The simulations demonstrate that, although the conventional optimization control shows better performance in initial half part of acceleration process, however, the overall acceleration performance turns to be worse whereas for the new one, the acceleration time from idle to 95% of the maximum power is surprising decreased by 1.4 s compared to the conventional optimization control.

In the coverage path planning (CPP) problem of an agricultural spraying UAV, a margin reduction algorithm was designed first to address special situations such as ditches and channels within the operational terrain. Regarding the particularity of a concave polygon area, an algorithm based on topology mapping was developed to judge the concave points of the concave polygon area, and the path with special concave points was scheduled. For the evaluation of the pesticide spraying mission, the flight distance and extra coverage ratio were the most appropriate optimization objectives. Therefore, this paper selected these two indicators to form a fitness function, then found the optimal operating heading angle of the mission after iterative optimization. Finally, the CPP for an agricultural spraying UAV in an arbitrary polygon area under the optimal heading angle was realized. The simulation and flight test results showed that the CPP method could significantly shorten the flight distance and reduce additional coverage, then avoid energy consumption and pesticide waste. In addition, the engineering practicability of the method was verified in this paper. This method can be popularized and widely used for an agricultural spraying UAV, which has great engineering application value.

A real-time optimization control method is proposed to enhance engine thrust response and enlarge its maximum thrust during emergent flight. This real-time optimization control is model based, and the on-board engine predictive model is devised by a multi-input multi-output recursive reduced least squares support vector regression method. Two emergency engine control modes during engine emergent acceleration process, the overthrust mode and the faster response mode, are redesigned by specifying relative objective function with engine operation constraints. Namely, the overthrust mode is for getting much bigger maximum thrust, and the faster response mode is for obtaining faster engine response. In the initial engine acceleration stage, the two modes have the same objective function for fastest thrust response within necessary operation constraints. After that, the objective function varies to maximum thrust in the overthrust mode, whereas the faster response mode keeps the objective for fastest response unchanged. For solving the online optimization problem, a feasible sequential quadratic programming algorithm is utilized here. The simulation results demonstrate that, first, engine response ability can be improved in faster response mode. Second, not only more thrust was provided over the maximum value but also fast response ability was achieved in the overthrust mode. Moreover, compared to conventional operation nowadays, argumentation of compressor guided vane angle control and broadening operation restrictions were deeply studied and verified in the new schemes.

As per few investigation in installed performance for variable cycle engines, an analysis scheme is proposed on the basis of integrating variable cycle engine and supersonic inlet system model. An integrated mathematical model, containing the inlet and the variable cycle engine is built, realizing the simulation of influences on the installation performance by varying geometry components. The impact on engine performance of variable geometric regulation was analyzed and concluded respectively. The experimental results show that the overflow resistance of the variable cycle engine with variable geometry optimization is reduced at subsonic cruise stage, and the installed fuel consumption is reduced, which significantly improves the installation performance.

In order to damp torsional vibrations in the helicopter, which would cause resonance in rotating components like engine, transmission and rotor, an adaptive notch filter is proposed. Instead of fixed notch filter, the adaptive one, with FFT analyzer and sorting algorithm, can damp the low-order torsional vibration signal with natural frequency varying in a wide range. Then, in order to enhance the power following capability of the engine, a nonlinear model predictive controller based on the supported vector machine is designed to compensate for the dynamic control performance. Through the adaptive notch filter, the torsional vibration of the free turbine speed whose frequency is away from the set-point value can effectively be suppressed by 50% compared with the fixed notch filter. Furthermore, instead of conventional PID controller, the nonlinear model predictive controller based on the adaptive notch filter can reduce the sag of the free turbine to less than 0.4%. Therefore, the control strategy achieves fast, high-quality response of the turbo-shaft engine.