Construction of a control system for disturbance rejection using a dual observer

A well‐known control system which can reduce the adverse effects of disturbances is a disturbance observer. However, in many cases of mechanical systems, system disturbances which do not satisfy the matching condition may be imposed. Therefore, it may be difficult to reduce the adverse effects of the disturbances by the traditional disturbance observer. In this paper, a method of control system synthesis for disturbance rejection using a dual observer is proposed. This method is based on the zeroing induced by the disturbance localization problem. This problem may be solved by dividing the state space into observable subspace and unobservable subspace. As compared with an H_∞ controller based on perfect observation, the usefulness of the proposed control system for disturbance rejection is demonstrated by numerical simulations for a two‐mass spring system. © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 50–60, 2002; DOI 10.1002/eej.1138     

Structure and Properties of Endosperm Starch and Water Soluble Polysaccharides from Sugary Mutant of Rice (Oryza sativa L.)

Structure and properties of starch and water soluble polysaccharides (WSP) from sugary (su) endosperm of rice were examined. The su starch contained more amylose and had a somewhat higher ratio of the short chains to the long chains of amylopectin than normal starch. The WSP consisted of short α-1, 4-chains and their average degree of polymerization was 8.6 glucose units. Susceptibility of the su starch to crude Rh. glucoamylase was higher than that of the normal. The initial and final temperatures and heat of gelatinization of the su starch granules were much lower than those of the normal ones.     

Discrimination of forearm''s motions by surface EMG signals using neural network

The effect of the antiviral, antitumoural xanthate D609 on the activity of phospholipase A2, C (PC- and Pi-specific) and D was investigated. D609 is the first model substance of a new concept of antiviral therapy that interferes with cellular regulation mechanisms, rather than with virus coded enzymes. Exclusively phosphatidylcholine (PC) specific phospholipase C (PC-PLC) was found to be inhibited in a dose-dependent manner. Enzyme activity was determined either as the rate of acid release from PC or as the rate of phosphorylcholine production form 3H labelled PC. Lineweaver-Burk plots revealed D609 as a competitive inhibitor of PC-PLC with a Ki of 6.4 microM. In addition, D609 competitively inhibited PC-PLC mediated cleavage of P-nitrophenylphosphorylcholine (p-NPP), a pseudo-substrate of PC-PLC with a Ki of 8.8 microM. These data suggest that D609 competes with the phosphorylcholine residue of PC for binding to PC-PLC.     

Kinetics of Iron Chlorination of Roasted Illmenite Ore,Fe2TiO5 in a Fluidized-Bed Reactor

The preferential chlorination reaction of iron constituents in roasted ilmenite ore was studied in an experimental fluidized bed reactor. The influence of the roasting temperature on the selectivity of chlorination reactions was also examined. It was found that preferential iron chlorination is dependent on roasted product morphology. Effects of chemical and process variables in the fluidized bed reactor, such as chlorination temperature, chlorine gas partial pressure, gas-solid contact time and the quantity of coke added, were investigated in order to study the kinetics of the preferential chlorination reaction. A modified bubble assemblage model was applied to analyze behavior of gases and solids in the reactor. The chlorination reaction rate constant was found to be a function of temperature and coke quantity present.     

Continuous intra-arterial infusion therapy via the occiptial artery for head and neck tumors: second choice treatment

We report three cases in which continuous intra-arterial infusion therapy via the occipital artery was combined with radiotherapy for head and neck tumors. An angiographic catheter was inserted into the feeding artery of the tumor retrogradely via the occipital artery under fluoroscopic guidance. Patients treated were maxillary sinus cancer, tongue cancer and hemangiosarcoma. No complications occurred due to this procedure in any of the three patients. This procedure was considered very useful when the approach from the superficial temporal artery was not possible due to prior treatment.     

Correlation between friction of articular cartilage and reflectance intensity from superficial images

The lubrication mechanism of articular cartilage is characterized by an efficient performance. In this work, friction of articular cartilage was evaluated with in-site images of articular surface. The images were captured with the laser light reflected at the interface between a prism and articular cartilage. The attenuation of reflectance was associated with the increase of the contact of collagen network of articular cartilage. The light reflectance and friction coefficient for short sliding presented a significant positive correlation. Friction tests were also carried out for short (30 s) and long (300 s) preloading times. The results indicate that depletion of fluid film is responsible for the increase of friction and the recovery of the fluid film was observed for the long preloading after the early stage of sliding.     

MATLAB在异步电动机直接转矩控制系统仿真中的应用

应用ＭＡＴＬＡＢ语言进行软件编制,能方便快捷地解决矩阵的多种运算及异步电机的直接转矩控制系统的仿真研究。