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Greenhouse climate is difficult to model as a complex nonlinear system. The solution to the problem of describing the relation between inputs and outputs is using T-S fuzzy modeling which could transform a nonlinear system into several linear systems. During the transition, c-means clustering is used to cluster the variable of inputs and outputs. The result of clustering determines the compose of...
Based on the optimal firing density of the future airspace window theory, according to the principle that the actual projectile impact point error variance should be the same with the projectile impact point error variance under the theoretical optimal firing density, we put forward the construction method about the aiming point configuration of circle future airspace window. At the same time, by...
Path following is a fundamental problem for unmanned air vehicles (UAVs). In this paper, a Lyapunov stable path guidance law is designed to generate the course control command for a small UAV. The control parameters of the guidance law is optimized by the nonlinear model predictive control (NMPC) techinque. The relative simulations with the three different approaches: Lyapunov stable controller with...
In order to detect obstacles on the runway without the ground obstacle detection system, a vision-based autonomous detection scheme is proposed in this paper. An algorithm based on adaptive singular value decomposition and reconstruction (AS VDR) is adopted to identify and segment the runway region accurately by combining Canny operator edge detection algorithm and Hough line detection algorithm....
Net recovery is an advanced accurate-point recovery way for small fixed-wing unmanned aerial vehicles (UAVs), especially in limited recovery fields or naval vessels. In order to perform recovery successfully, the aerial vehicle must satisfy certain conditions to shut down the engine so that it can glide into the net without a crash. In this paper, an aircraft longitudinal dynamic model is taken into...
The landing accuracy of a Mars entry vehicle will be degraded duo to uncertain factors in the atmospheric entry process and a novel composite guidance law, having a composite hierarchical framework, is presented to improve the landing accuracy in this paper. It could eliminate the constraint that maximum boundary value of uncertain factors must be known in advance in the multiple sliding surface guidance...
Through studying the K-L transformation (Karhunen-Loeve transformation) theory deeply, it is found that the transformation matrix is too large to be used for the compression coding of ordinary digital images. In this paper, we propose the improvement and optimizing method for this problem, and use the Feng Yun No.2 meteorological satellite cloud image to segment the image which is consist of different...
In this paper, an improved cascade second-order sliding mode (SOSM) methodology for a polymer electrolyte membrane (PEM) fuel cell air supply system is proposed. Based on the simplified six-order nonlinear model, the control objective oxygen excess ratio is achieved by using SOSM algorithm. Besides, parametric uncertainty and noise are presented in the dynamic fuel cell model. The modified two stage...
This paper investigates the finite-time consensus tracking problem for a group of quadrotor aircraft with a leader-follower structure. Based on finite-time algorithms, the finitetime position controller and attitude controller are designed respectively in this note. Based on homogenous system theory and Lyapunov theory, the finite-time stability of the closed-loop systems is given and it is shown...
Maneuvering aircraft tracking under low accuracy observations is a challenge. To solve this problem, we constructed the corresponding dynamic model for different flying states of aircraft. Then we combined the models of different flying states into single one. Since an accurate dynamic model is a strong constraint for the flying trajectory of aircraft, the trajectory should follow the dynamic characteristic...
Fuel starvation during PEMFC (proton exchange membrane fuel cell) operations can produce serious irreversible damages. A large over-pressure, i.e., the differential pressure between the anode and cathode, would damage the proton exchange membrane like causing pinholes and reducing the performance of PEMFC. In order to ensure the safe and stable operation of PEM fuel cell, this paper proposes a fuel...
This paper proposes the application of multiobjective model predictive control to achieve a dynamic optimization of boiler combustion system. The utopia point of the multi-objective model predictive control system is firstly calculated, and the optimal control sequence is then determined by finding the trade-off solution closed to the utopia point. By using this approach, the arbitrary weighting functions,...
During the operation of the coal-fired boiler, dust and slag will accumulated in the inner heat exchange surface. Removing the dust and slag is able to improve production efficiency, reduce pollution emissions and decrease production accidents. It is widely used in many plants due to its advantages like large dust removing area, low energy consumption and low investment. In this paper, a new structure...
In order to meet modeling accurately and fault simulation required, according to the working principle of Solid Oxide Fuel Cell(SOFC) Generated Elections System, dividing function module, analyzing which fault modes, building fault mathematical model and verifying model. The result shows the SOFC system fault model reflect the relation among the different module clearly and simulate fault mode effective...
This paper introduces the application of model based systems engineering (MBSE) method in designing cabin pressurization control system (PCS) for civil aircraft. Rhapsody and Simulink are used as the design and simulation tools. Use cases, functions flow, and state-machines of the system are built by corresponding models in three MBSE design phases, i.e. requirements analysis, function analysis and...
Aiming at the complicated mechanism of the sintering process of the roller kiln and the large delay in the temperature change of the kiln, which brings difficulties to the precise temperature control. This paper presents the integrated model of roller kiln temperature prediction combined with the fusion mechanism and data model. Firstly, based on the analysis of the heat transfer mechanism in the...
Energy saving of compressed air system was studied in this work. The whole process model including compressor's performance, pressure loss of pipeline and pressure change of storage tank was founded. And then compared with performance equations of FSD compressors, energy cost and related Volumetric efficiency change along the variable frequency was achieved. With these models founded, simulations...
In order to realize the ultra-precision and the large stroke of positioning, a positioning platform based on double bellows is designed. The platform is directly driven by the new type of metal bellows, and is guided and supported by the air float guide bearing which can reduce the sliding friction. And the Mercury series grating ruler is used to detect the position in real time. By analyzing the...
In this paper, firstly, the energy conservation equation of the cold side and the hot side of the precooler is written according to the energy conservation. Then the model of the precooler is established based on Matlab S-Function, and the model is simulated. The cold side helium mass flow is reduced to obtain the curve of the heat side temperature change, and the transfer function of the cold side...
In the distillation process, many important process variables are often difficult to be measured online. For example, the aviation kerosene is an important index of operation quality, but current methods cannot obtain the real-time value of the aviation kerosene efficiently. To solve this problem, a method of selecting the input variable based on partial least squares regression (PLS) is proposed...
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