Implementation of real-time parallel processing in a motion control system

The paper proposes an architecture and implementation of a motion control system, with a master-slave multiprocessor mode. Some major problems which must be considered in multiprocessor systems design, including multiprocessor system architecture, interconnection network, hardware circuit design and software design are studied.published_or_final_versio

Learning from Multiple Sources for Video Summarisation

Many visual surveillance tasks, e.g.video summarisation, is conventionally accomplished through analysing imagerybased features. Relying solely on visual cues for public surveillance video understanding is unreliable, since visual observations obtained from public space CCTV video data are often not sufficiently trustworthy and events of interest can be subtle. On the other hand, non-visual data sources such as weather reports and traffic sensory signals are readily accessible but are not explored jointly to complement visual data for video content analysis and summarisation. In this paper, we present a novel unsupervised framework to learn jointly from both visual and independently-drawn non-visual data sources for discovering meaningful latent structure of surveillance video data. In particular, we investigate ways to cope with discrepant dimension and representation whist associating these heterogeneous data sources, and derive effective mechanism to tolerate with missing and incomplete data from different sources. We show that the proposed multi-source learning framework not only achieves better video content clustering than state-of-the-art methods, but also is capable of accurately inferring missing non-visual semantics from previously unseen videos. In addition, a comprehensive user study is conducted to validate the quality of video summarisation generated using the proposed multi-source model

Robustness analysis of induction motor decoupling adaption system

By using linear analysis, the robustness of an induction motor decoupling adaptation system is studied and quantitative analytical results are given. The simulation results of the system verify the analytical results.published_or_final_versio

Permanent magnet brushless drives

The purpose of this paper is to present an optimal efficiency control scheme for constant power operation of phase decoupling (PD) PM brushless DC motor drives. The key is to adaptively adjust the advanced conduction angle to minimize the system losses for a given operation point in the constant power region. The strategy for constant power operation of PD PM brushless DC motor drives is exemplified using a 5-phase 22-pole PD PM brushless DC motor. In the sections that follow, the newly-developed optimal efficiency control technique is then illustrated. Then, after describing the corresponding implementation, both computer simulation and experimental results are presented, and some conclusions are offered.published_or_final_versio

Optimal-efficiency control for constant-power operation of phase-decoupling permanent-magnet brushless motor drives

In this paper, a control approach to optimize the system efficiency of phase-decoupling (PD) permanent-magnet (PM) brushless motor drives during constant-power operation is presented. The approach is to adaptively adjust the advanced conduction angle to minimize the total system losses for a given operation point in the constant-power region. The corresponding minimum total losses are determined by minimizing the input current for a fixed voltage source. Both computer simulation and experimental results are given for illustration.published_or_final_versio

Novel permanent magnet motor drives for electric vehicles

Novel permanent magnet (PM) motor drives have been successfully developed to fulfil the special requirements for electric vehicles such as high power density, high efficiency, high starting torque, and high cruising speed. These PM motors are all brushless and consist of various types, namely rectangular-fed, sinusoidal-fed, surface-magnet, buried-magnet, and hybrid. The advent of novel motor configurations lies on the unique electro-magnetic topology, including the concept of multipole magnetic circuit and full slot-pitch coil span arrangements, leading to a reduction in both magnetic yoke and copper, decoupling of each phase flux path, and hence an increase in both power density and efficiency. Moreover, with the use of fractional number of slots per pole per phase, the cogging torque can be eliminated. On the other hand, by employing the claw-type rotor structure and fixing an additional field winding as the inner stator, these PM hybrid motors can further provide excellent controllability and improve efficiency map. In the PM motors, by purposely making use of the transformer EMF to prevent the current regulator from saturation, a novel control approach is developed to allow for attaining high-speed constant-power operation which is particularly essential for electric vehicles during cruising. Their design philosophy, control strategy, theoretical analysis, computer simulation, experimental tests and application to electric vehicles are described. © 1996 IEEE.published_or_final_versio

Localized surface optical phonon mode in the InGaN/GaN multiple-quantum- wells nanopillars: Raman spectrum and imaging

An interesting phonon mode at around 685-705 cm -1 was clearly observed in the Raman spectra of InGaN/GaN multiple-quantum-wells nanopillars with different diameters at room temperature. The Raman peak position of this mode is found to show a distinct dependence on the nanopillar size, which is in well agreement with theoretical calculation of the surface optical (SO) phonon modes of nanopillars. Moreover, this kind of SO phonon was evidenced to be located on the pillar surface by using scanning confocal micro-Raman microscopy. © 2011 American Institute of Physics.published_or_final_versio