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The note is devoted to the interval observer design problem for discrete-time switched systems. By designing a suitable interval observer, it is convenient to achieve the interval estimation bounds of system states and reduce the effect of the unknown external disturbance. The interval observer design method has two main steps. They are $H_{\infty }$ observer design and interval hull design respectively. Besides, the superiority of the proposed method is proved in the aspect of theory. One comparative example is carried out to verify the conclusion above. [ABSTRACT FROM AUTHOR]

Incoherent noise is one of the most common noise widely distributed in seismic data. To improve the interpretation accuracy of the underground structure, incoherent noise needs to be adequately suppressed before the final imaging. We propose a novel method for suppressing seismic incoherent noise based on the robust low-rank approximation. After the Hankelization, seismic data will show strong low-rank features. Our goal is to obtain the stable and accurate low-rank approximation of the Hankel matrix and then reconstruct the denoised data. We construct a mixed model of the nuclear norm and the $l_{1}$ norm to express the low-rank approximation of the Hankel matrix constructed in the frequency domain. Essentially, the adopted model is an optimization for the subspace similar to the online subspace tracking method, thus avoiding the time-consuming singular value decomposition (SVD). We introduce the orthonormal subspace learning to convert the nuclear norm to the $l_{1}$ norm to optimize the orthonormal subspace and the corresponding coefficient. Finally, two optimization strategies—the alternating direction method and the block coordinate descent method—are applied to obtain the optimized orthonormal subspace and the corresponding coefficient for representing the low-rank approximation of the Hankel matrix. We perform incoherent noise attenuation tests on synthetic and real seismic data. Compared with other denoising methods, the proposed method produces small signal errors while effectively suppressing the seismic incoherent noise and has a high computational efficiency. [ABSTRACT FROM AUTHOR]

The electro-mechanical brake booster (EMBB) is a kind of mechatronic actuator, which is developed to suit the brake assist requirement of electric vehicles. In this paper, we report on the design of an EMBB system consisting of a dc motor, a two-state reduction of a gear and ball screw, a servo body, and a reaction disk. Considering the inconvenience of installation and high price of the pedal force sensor, we translate the control problem of brake power assist control to position tracking control. Meanwhile, a nonlinear control method for position tracking is presented to solve the problem of power assist braking, which is formalized as three parts: the steady-state control, feed-forward control based on reference dynamics, and state-dependent feedback control. The benefit of the nonlinear control method is that it offers a concise control law and performs well in engineering implementations. In addition, a second-order filter was designed to do the signal processing and obtain a higher-order derivative. Finally, the bench tests based on rapid control prototyping environment were designed and implemented to verify the performance of the controller. Test results show that both the position tracking performance and response time of the EMBB system performed well. [ABSTRACT FROM AUTHOR]

The antenna-on-chip (AoC) presents an excellent solution for applications requiring higher integration levels and lower cost; however, its radiation performance is poor due to the inherent lossy Si substrate in conventional complementary metal–oxide–semiconductor (CMOS) processes. It is well known that every chip requires a package to protect it from the environment; however, this package does not provide any functionality, despite adding to the cost and required space. In this article, we propose a functional package that has been designed to enhance the gain of the AoC. A 71 GHz coplanar waveguide (CPW)-fed on-chip monopole antenna, driven by a voltage-controlled oscillator (VCO) and frequency doubler, was realized in the standard 0.18 $\mu \text{m}$ CMOS technology. As a first step to enhance its gain, the AoC was designed on top of an artificial magnetic conductor (AMC) surface. Further gain enhancement was achieved by transforming the chip package into a combination of a superstrate layer and a Fresnel lens, qualifying this as a system-on-package (SoP). The package has been realized through additive manufacturing to maintain the low-cost aspect. Overall, the measured gain of the packaged AoC is 6.8 dBi, which has been enhanced by ~20 dBs compared to the unpackaged antenna without an AMC layer. [ABSTRACT FROM AUTHOR]

Landslide is one of the most disastrous geological hazards in the Pearl River Delta area. In the article, landslide susceptibility index (LSI) and analytical hierarchy process (AHP) have been adopted to assess landslide susceptibility (LS) of the Pearl River Delta area. A total of 294 historical landslide sites were extracted from China Geological Survey Result CGS2015-008 and remote sensing images as landslide inventory. In each experiment, 198 landslide points were randomly selected as training samples and the remaining 96 as verification samples. Nine influencing factors, i.e., standard deviation (STD) of elevation, terrain roughness, curvature, lithology, fault, land use, water density, road density, and aspect, were obtained through ASTER GDEM, China Geological Survey Result CGS2015-008, Geographical Information Monitoring Cloud Platform, Open Street Map, and Google Earth. LSI was used to represent the contribution of each category within the influencing factors to the occurrence of landslides (LSIi), and AHP was used to calculate the weights between different influencing factors (Wi). Finally, the summation of the product of LSIi by Wi was used to represent the LS value for each pixel. Then, the study area was grouped into five susceptibility classes based on the landslide susceptibility. It is indicated that terrain factors have the greatest impact on landslides, followed by engineering geological lithology and land use types. The high and very high susceptibility classes were mainly distributed in the area of: 1) STD of elevation of 0.8–2.5, roughness of 1.004–1.030, and curvature 2.7–7.2; 2) sand-shale stone and coal, bedded clastic rock, and bedded epimetamorphic rock; and 3) woodland and the urban and rural land. The receiver operating characteristic curves of many experimental results prove that the model has fine prediction performance and good stability. This article could provide a basis for landslide prevention and land development in the Pearl River Delta area. [ABSTRACT FROM AUTHOR]

Presents approaches to eliminating common-mode voltage when using multilevel pulsewidth modulation inverters. Modulation schemes for common-mode voltage elimination; Simulation and experimental results.

Presents a study which compared mitigation techniques for bearing currents, electromagnetic interference (EMI) and overvoltages in adjustable-speed drives (ASD) applications. ASD issues; Application of ASD for speed control of alternating current (ac); Adverse effects of applying ASD to ac motors.

Presents information on a study which examined a dual-bridge inverter approach to eliminate the motor common-mode voltage and resulting bearing and leakage currents. Theoretical analysis and control of the proposed dual-bridge inverter; Description of the motor winding configuration; Simulation results.