功率分配用双定子永磁无刷电机设计与电磁特性分析

介绍了一种混合动力汽车(HEVs)功率分配用双定子永磁无刷(DS-PMBL)电机内外定子绕组功率合理配置的设计方法,导出了电机的尺寸方程,设计并制造了一台额定功率为2.5kW的样机。基于二维有限元法对电机的反电动势、电感、定位力矩等电磁特性进行了计算和分析。样机实验结果验证了设计方法和理论分析的正确性,为该电机用作HEVs功率分配装置的进一步研究奠定了基础。     

Intelligent phase plane switching control of a pneumatic muscle robot arm with Magneto-Rheological Brake

Pneumatic cylinders are one kind of low cost actuation sources which have been applied in industrial and robotics field, since they have a high power/weight ratio, a high-tension force and a long durability. To overcome the shortcomings of conventional pneumatic cylinders, a number of newer pneumatic actuators have been developed such as McKibben Muscle, Rubber Actuator and Pneumatic Artificial Muscle (PAM) Manipulators. However, some limitations still exist, such as the air compressibility and the lack of damping ability of the actuator bring the dynamic delay of the pressure response and cause the oscillatory motion. In addition, the nonlinearities in the PAM manipulator still limit the controllability. Therefore, it is not easy to realize motion with high accuracy and high speed and with respect to various external inertia loads. To overcome these problems, a novel controller which harmonizes a phase plane switching control method (PPSC) with conventional PID controller and the adaptabilities of neural network is newly proposed. In order to realize satisfactory control performance a variable damper, Magneto-Rheological Brake (MRB), is equipped to the joint of the robot. The mixture of conventional PID controller and an intelligent phase plane switching control using neural network (IPPSC) brings us a novel controller. The experiments were carried out in a robot arm, which is driven by two PAM actuators, and the effectiveness of the proposed control algorithm was demonstrated through experiments, which had proved that the stability of the manipulator can be improved greatly in a high gain control by using MRB with 1PPSC and without regard for the changes of external inertia loads.     

Formation of N2O and (NO)2 During NO Adsorption on Au 3D Crystals

The adsorption of NO on Au 3D hemispherical crystals (field emitter tips) has been studied by means of pulsed field desorption mass spectrometry (PFDMS) under dynamic gas flow conditions and at 300 K. Local chemical probing of ~200 Au sites in the stepped surface region between the central (111) pole and the peripheral (001) plane leads to the detection of NO⁺, N₂O⁺ and (NO) species. Obviously, molecular NO adsorption on stepped Au surfaces can lead to dimerization. Nitrous oxide formation probably occurs via the dimer, (NO)₂.