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Aeroengine controller is a crucial and complex component aimed at pursing optimal performance while satisfying all kinds of physical and operational constrains. A novel control technique, multivariate constrained predictive control based on linear state space model, is applied to a commercial turbofan engine. To be specific, according to the control requirements of turbofan engine, its outputs are classified into two types, controlled or constrained; they are then incorporated into the cost function and the inequality constraint condition of baseline MPC algorithm respectively. Further, since key parameters of MPC play an important role in obtaining optimal performance, their selection is studied. It is shown that control performance using improved MPC is better than that of PID controller for a big disturbance while maintaining within prescribed constrains.

Tribological properties of ceramic cutting tool materials in contact with wood based materials were studied in this paper by examining how Al2O3-ceramics and Si3N4-ceramics behave in dry sliding experiment in contact with wood-based materials and by comparing their behavior with tungsten carbide material at the same time. It had been found that the ceramics exhibited much better tribological properties than tungsten carbide material, and Si3N4-ceramic performed better than Al2O3-ceramics. The Al2O3-ceramics with an addition of ZrO2 had better tribological performance than the common Al2O3-ceramics in contact with wood-based materials. The tungsten carbide had better tribological performance than ceramics in tribological contact with wood flour/PE material. A well-marked difference occurred in various cutting materials/MDF frictional pair, but the differences in various cutting materials/PB frictional pair were insignificant. An increase of the normal force didn’t result in any significant decrease of the friction coefficient. An addition of ZrO2 in the Al2O3-ceramics could inhabit corrosive wear.

Tea flushes identification from their natural background is the first key step for the intelligent tea-picking robot. This paper focuses on the algorithms of identifying the tea flushes based on color image analysis. A tea flushes identification system was developed as a means of guidance for a robotic manipulator in the picking of high-quality tea. Firstly, several color indices, including y-c, y-m, (y-c)/(y+c) and (y-m)/(y+m) in CMY color space, S channel in HSI color space, and U channel in YUV color space, were studied and tested. These color indices enhanced and highlighted the tea flushes against their background. Afterwards, grey level image was transformed into binary image using Otsu method and then area filter was employed to eliminate small noise regions. The algorithm and identification system has been tested extensively and proven to be well adapted to the complexity of a natural environment. Experiments show that these indices were particularly effective for tea flushes identification and could be used for future tea-picking robot development.

The fuzzy control technology is a kind of intelligent control method, and it has strong robustness. The fuzzy control strategy is used to choose the control currents of MR dampers in this paper. In order to illustrate how to design the fuzzy controller, three kinds of the fuzzy controller having different membership functions and fuzzy rules are designed. A five-floor MR structure using the designed different fuzzy controllers is simulated. Analysis results show that for the MR structure, it is not best that MR dampers provide the maximum forces to the structure, so the displacement and acceleration responses of the structure must be weighed at the same time to make MR dampers provide reasonable forces when the membership functions and fuzzy rules are designed.

The magnetic particles coated with the carbon are used in the magneto-rheological fluids (MRFs) and the coat-like structure slow down the sedimentation of MRFs. Meanwhile, after the performance tests, the new MRF has the low viscosity and good ability of the recovery. These characters have more advantages in the application fields. Based on the prepared MRF, a shearing model that considers the interaction force between the adjacent chains was presented. By applying the proposed model, some conclusions are reached. The volume ratio of the magnetic particles has an important effect on the yield stress of the MRFs. The shear strain where the maximum shear stress happened has something to do with the volume ratio of the magnetic particles.

This paper gives an experimental research on slightly contaminated raw water by utilizing the combined technology of electro-flotation and suspending TiO2 photochemical catalysis. During the static experiment of degrading humic acid by electro-flotation—suspended TiO2 photochemical catalysis, the ratio of CODMn removal reaches 87.8% in such conditions as two ultraviolet germicidal lamps of 10W, the voltage of 20V, the current of 0.4A, 0.5cm intervals of two groups of plates, the TiO2 dosage of 1g/L and the reaction time of 150 minutes. The preferable synergistic effect can be achieved when combining electro-flotation and photocatalytic oxidation together.

By using parallel process of photocatalysis-biological contact oxidation, a research on the pretreatment effect of micro-polluted raw water was conducted. The result indicates that the changes of HRT and the initial concentration take significant impact on the removal of NH3-N. 60min is the best residence time for the pretreatment. Once the thickness of composite media is 120mm, the removal efficiency of CODMn may reach as much as 15.55%, while the average removal efficiency of turbidity is 20%. Since the nitration reaction consumes certain amount of alkalinity, the pH value of outlet water is lower than inlet water. When employing parallel process, biological oxidation and photocatalysis are performed and finished in the same reactor simultaneously, conducing to maintaining a moderate level of the removal of CODMn and NH3-N. All these are of reference value for its application in practical engineering projects.