The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper presents the experimental implementation of a controller for the rotor position of a separately-excited DC Motor. The control law was designed by using a dynamic model for the motor and a dynamic model for the load torque. The torque model was proposed in order to improve the performance of the closed loop system. Discrete state feedback, discrete integrator and a discrete state observer...
This chapter proposes a novel design methodology for a Multi-stAge noise SHaping (MASH) digital delta–sigma modulator (DDSM) which employs multi-moduli. The structure is termed the MM-MASH. The adequacy and benefit of using such a structure is demonstrated. In particular, the sequence length is lengthened if the quantizer modulus of the first-order error feedback modulator (EFM1) of each stage are...
The development procedure of permanent magnet drives for sensor less operation beginning from standstill under overload conditions has to consider different design aspects coevally. First, the robust rotor position sensing by test signal enforces a design with a strongly different behavior of the spatial dq-oriented differential inductance values. Therefore, the interior rotor magnet array arrangement...
The structure characteristics and working principle of silicon resonant micro-accelerometer based on electrostatic rigidity are presented. Dynamic characteristics of double-ended tuning fork (DETF) in the sensor are analyzed. Force equilibrium equations of mass and DETF are built respectively for with or without acceleration, through which the relationship between DETF resonant frequency and acceleration...
A novel dual-pulse voltage driver has been proposed to reduce dielectric charging in micro-electromechanical system (MEMS) switch, leading to a longer switch lifetime. Mathematical and transient circuit models have been utilized to simulate dielectric charging in the RF MEMS switch, enabling the analysis of charge built-up at the switch dielectric and substrate brought about by the actuation voltage...
Controlling rotary wing platforms, especially helicopters, is a difficult problem because of the nonlinearity of the structure and strong coupled motion dynamics. In this paper, linear quadratic regulator method is used to control the trajectory and mission paths of the autonomous helicopter. Nonlinear motion dynamics is trimmed and linearized about certain operating points and linear model is obtained...
From the rating plate data of an induction motor the nominal efficiency can be determined. Without detailed knowledge of equivalent circuit parameters, partial load behavior cannot be computed. Therefore, a combined calculation and estimation scheme is presented, where the consistent parameters of an equivalent circuit are elaborated, exactly matching the nominal operating point. From these parameters...
This paper presents a physical model of a squirrel cage induction machine with rotor topology. The machine is modeled in Modelica, an object oriented multi physical modeling system. The presented machine model is used to investigate electrical rotor asymmetries in induction machines. For the case of a single broken rotor bar a simulation model is compared with measurement results.
This paper presents two simulation models for two variants of a large chipper drive used in a paper mill. If a slip ring induction motor is used, the impact of a rotor circuit rheostat with respect to starting behavior and heavy duty load impulses can be examined. Furthermore a speed controlled squirrel cage induction machine will be investigated. The modeling language for both drives is Modelica...
Macro cells are used more and more in current designs as they provide the benefit of reusability directly resulting in the decrease in design time and cost. However, there lies a gap in the EDA industry for macro-cell placement tools. This chapter looks at the implementation of a force-directed macro-cell placement tool that is developed to target the gap in industry.
The comprehensive Ando’s surface roughness (SR) model examined for nMOSFETs. Four distinct source terms contribute in SR scattering. Relative strength of these contributing source terms are evaluated and compared. The most influential term turned out to be due to scattering with the “physical steps” at the interface. Remote SR scattering is also significant in ultra-thin MOS structures. The proposed...
Efficient neural network based adaptive equalisations for digital communication channels have been suggested in recent past. Recurrent neural network (RNN) exhibits better performance in nonlinear channel equalization problem. In this present work a hybrid model of recurrent neural equaliser configuration has been proposed where a Discrete Cosine Transform (DCT) block is embedded within the framework...
The hypercube parallel architecture is one of the most popular interconnection networks due to many of its attractive properties and its suitability for general purpose parallel processing. An attractive version of the hypercube is the crossed cube. It preserves the important properties of the hypercube and most importantly reduces the diameter by a factor of 2. In this chapter, we show the ability...
Software fault tolerance demands additional tasks like error detection and recovery through executable assertions, exception handling, diversity and redundancy based mechanisms. These mechanisms do not come for free; rather they introduce additional complexity to the core functionality. This paper presents light weight error detection and recovery mechanisms based on the rate of change in signal or...
Performances of speaker verification systems are superb in clean noise-free conditions but the reliability of the systems drop severely in noisy environments. In this study, we propose a novel approach by introducing Support Vector Machine (SVM) as indicator system for audio reliability estimation. This approach directly validate the quality of the incoming (claimant) speech signal so as to adaptively...
This article presents a discussion on the impact of Hardware-assisted Virtualization for the ×86–64 architecture. A quantitative performance analysis has been done using a simple prototype of a purely Hardware-assisted Virtual Machine Monitor. The performance impact is measured in terms of the CPU time consumed by certain critical sections of Virtualization specific code. The analysis reveals that...
Software quality assessment models are quantitative analytical models that are more reliable compared to qualitative models based on personal judgment. These assessment models are classified into two groups: generalized and product-specific models. Measurement-driven predictive models, a subgroup of product-specific models, assume that there is a predictive relationship between software measurements...
The use of heterogeneous architectures in embedded systems together with the increasing complexities of hardware and software, the increased pressure to deliver full-featured products with reduced time-to-market, and the fact that more embedded systems are using dedicated hardware components (ASIC) and software running on processors is more and more increasing the complexity of designing embedded...
The design of dynamic, adaptable discrete-event systems calls for adequate modeling formalisms and tools in order to manage possible changes occurring during system’s lifecycle. A common approach is to pollute the design with details not concerning the current system behavior, rather its evolution. That hampers analysis, reuse and maintenance in general. A Petri net-based reflective model (based on...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.