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Robot calibration highly depends on redundant measurement configurations to collect enough sample data for higher accuracy, but excessive measurements seem to be uneconomical and time-consuming. Thus lots of observability indexes to evaluate the goodness of the measurement configurations have been proposed. However, in some circumstances, it is of critical importance to obtain accurate kinematic parameters and estimate the end-effector pose precisely at the same time. Obviously one single observability index can hardly meet this need yet. Accordingly, after analyzing the essential constrains of robot calibration and the influence of measurement configurations on the observability indexes, an optimization model with two observability indexes to be taken into consideration is proposed in this paper, and then the existing DETMAX algorithm is modified to seek optimal design of measurement configurations, by adopting a set-constructing method and a set-shrinking method. Much better results have been obtained by simulation study, which implies that the proposed model and the modified DETMAX algorithm perform well in both kinematic parameter identification and pose estimation of the end-effector of the robot. [ABSTRACT FROM AUTHOR]

ABSTRACT Design centering is a design problem which looks for nominal values of circuit parameters that maximize the probability of satisfying the design specification (yield function). Direct yield optimization of electromagnetic (EM)-based circuits is obstructed by the high expense of EM simulations required in the yield estimation process. Also, the absence of any gradient information represents an obstacle against the optimization process. In this article, a new approach for design centering and yield optimization of EM-based circuits is introduced. In the proposed approach, the generalized space mapping (SM) technique is incorporated with a derivative-free trust region optimization method (NEWUOA). Moreover, a variance reduction sampling technique is implemented in the yield estimation process. Two techniques suitable for the microwave circuit design centering process are introduced. The first technique exploits the surrogate developed using any circuit optimizer, for example, minimax optimizer, in the yield maximization process. While the second technique iteratively constructs and updates an SM surrogate during the yield optimization process. Our novel approach is illustrated by practical examples showing its efficiency. One of the examples is entirely designed within the sonnet em environment. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:474-484, 2015. [ABSTRACT FROM AUTHOR]

This paper presents a novel harmonic identification algorithm of shunt active power filter for balanced and unbalanced three-phase systems based on the instantaneous power theory called instantaneous power theory with Fourier. Moreover, the optimal design of predictive current controller using an artificial intelligence technique called adaptive Tabu search is also proposed in the paper. These enhancements of the identification and current control parts are the aim of the good performance for shunt active power filter. The good results for harmonic mitigation using the proposed ideas in the paper are confirmed by the intensive simulation using SPS in SIMULINK. The simulation results show that the enhanced shunt active power filter can provide the minimum%THD (Total Harmonic Distortion) of source currents and unity power factor after compensation. In addition, the %THD also follows the IEEE Std.519-1992. [ABSTRACT FROM AUTHOR]

A heavy-duty parallel hybrid electric truck is modeled, and its optimal energy control is studied in this paper. The fundamental architecture of the parallel hybrid electric truck is modeled feed-forwardly, together with necessary dynamic features of subsystem or components. Dynamic programming (DP) technique is adopted to find the optimal control strategy including the gear-shifting sequence and the power split between the engine and the motor subject to a battery SOC-sustaining constraint. Improved control rules are extracted from the DP-based control solution, forming near-optimal control strategies. Simulation results demonstrate that a significant improvement on the fuel economy can be achieved in the heavy-duty vehicle cycle from the natural driving statistics. [ABSTRACT FROM AUTHOR]

The conversion efficiency of a solar cell can substantially be increased by improved material properties and associated designs. At first, this study has adopted AMPS-1D (analysis of microelectronic and photonic structures) simulation technique to design and optimize the cell parameters prior to fabrication, where the optimum design parameters can be validated. Solar cells of single junction based on hydrogenated amorphous silicon (a-Si:H) have been analyzed by using AMPS- 1D simulator. The investigation has been made based on important model parameters such as thickness, doping concentrations, bandgap, and operating temperature and so forth. The efficiency of single junction a-Si:H can be achieved as high as over 19% after parametric optimization in the simulation, which might seem unrealistic with presently available technologies. Therefore, the numerically designed and optimized a-SiC:H/a-SiC:H-buffer/a-Si:H/a-Si:H solar cells have been fabricated by using PECVD (plasma-enhanced chemical vapor deposition), where the best initial conversion efficiency of 10.02% has been achieved (Voc = 0.88V,Jsc = 15.57 mA/cm² and FF = 0.73) for a small area cell (0.086 cm²). The quantum efficiency (QE) characteristic shows the cell's better spectral response in the wavelength range of 400 nm-650 nm, which proves it to be a potential candidate as the middle cell in a-Si-based multijunction structures. [ABSTRACT FROM AUTHOR]