Showing papers by "Norbert C. Cheung published in 2007"
TL;DR: A self-tuning regulator (STR) is proposed to combat the difficulties and uncertain control behaviors of the LSRM and is a low-cost solution to fast, accurate, and reliable position tracking for many demanding motion control applications.
Abstract: In the high-technology mass manufacturing industry, high-speed and high-precision motion is an indispensable element in the automated production machines. In recent years, there has been a growing tendency to employ direct drive permanent magnet linear synchronous motors in demanding motion applications. Although the overall performance is good, its implementation cost remains high. This is mostly due to the cost of the Neodymium-Boron magnets, the manufacturing of the magnetic rails, and the precision of the overall mechanics. In this paper, a much cheaper alternative is proposed-to use a low-cost linear switched reluctance motor (LSRM) and an adaptive control strategy to overcome the tolerances and difficult control characteristics inherent in the motor. The LSRM has simple and robust structure, and it does not contain any magnets. However, its force is solely drawn from the reluctance change between the coil and the steel plates. Variations on the behavior of these two elements due to different operating conditions will change the motion behavior of the motor. Also, to keep the overall cost low, the LSRM sets a marginal mechanical tolerance during its mass production. This leads to characteristic variations in the final product. Finally, since the LSRM is a direct drive motor, any variations on the motor characteristics will directly reflect on the control system and the motion output. In this paper, a self-tuning regulator (STR) is proposed to combat the difficulties and uncertain control behaviors of the LSRM. This paper first introduces the motor winding excitation scheme, the model of the LSRM, and the current control method. The LSRM system is modeled as a single-input single-output discrete model with its parameters estimated by the recursive least square (RLS) algorithm. Then, an STR based on the pole placement algorithm is applied to the LSRM for high- performance position tracking. Both the simulation investigation and the experimental verification were conducted. In both cases, the results verified that the proposed RLS algorithm can estimate the parameters with fast convergence. The STR can provide quick response and high precision which is robust to the change of system parameters. Combined with STR control, the LSRM is a low-cost solution to fast, accurate, and reliable position tracking for many demanding motion control applications.
77 citations
01 Nov 2007
TL;DR: In this article, a fuzzy logic controller is used to control wheel slip for ABS in electric vehicles to enhance the vehicle stability and safety under highly nonlinear and time variant braking conditions simulation was used to derive a rule base and robustness of the fuzzy-logic slip regulator is further tested by applying the resulting controller over a wide range controller over different operating conditions.
Abstract: In this paper, the braking strategy is developed for electric vehicle which includes regenerative braking and anti-lock brake system (ABS) Induction motor is used in EV to regenerate kinetic energy This paper describes the preliminary research and implementation of a fuzzy logic controller to control wheel slip for ABS The controller is used to enhance the vehicle stability and safety under highly nonlinear and time variant braking conditions Simulation was used to derive a rule base The robustness of the fuzzy-logic slip regulator is further tested by applying the resulting controller over a wide range controller over a wide range of operating conditions
13 citations
01 Nov 2007
TL;DR: In this paper, a contactless power converter is examined for power transfer in intelligent clothing, which has a number of electronic devices that require power using magnetic coupling, the power can be transferred Magnetic and circuit design, analysis and test will be presented in the paper.
Abstract: The contactless power converter is examined here for power transfer in intelligent clothing which has a number of electronic devices that requires power Using the contactless power converter that is based on magnetic coupling, the power can be transferred Magnetic and circuit design, analysis and test will be presented in the paper A gapped design is used for the magnetic device and a compensation method is implemented in the transformer primary and secondary sides for improvement for power transfer
9 citations
23 May 2007
TL;DR: A novel approach is proposed to model the behavior of a commercial 1.8deg hybrid stepper motor accurately and efficiently and damping algorithms for open loop and servo control are proposed.
Abstract: It is well known that commercial hybrid stepper system has one or more low speed resonant points. However, this characteristic is not accurately modeled without high order equations or complicated measurement of motor parameters. In this paper, a novel approach is proposed to model the behavior of a commercial 1.8deg hybrid stepper motor accurately and efficiently. Damping algorithms for open loop and servo control are proposed. Both simulation and experiment results show that the proposed algorithms can effectively eliminate low speed resonance and vibration of the stepper system.
9 citations